HANDBOOK ON FABRIC MANUFACTURING: grey fabrics 9789385059162, 9789385059711, 9385059165

Citation preview

114337

Handbook on fabric manufacturing (grey fabrics: preparation, weaving to marketing)

B. Purushothama

WOODHEAD PUBLISHING INDIA PVT LTD New Delhi

Published by Woodhead Publishing India Pvt. Ltd. Woodhead Publishing India Pvt. Ltd., 303, Vardaan House, 7/28, Ansari Road, Daryaganj, New Delhi - 110002, India www.woodheadpublishingindia.com

First published 2016, Woodhead Publishing India Pvt. Ltd. © Woodhead Publishing India Pvt. Ltd., 2016 This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission. Reasonable efforts have been made to publish reliable data and information, but the authors and the publishers cannot assume responsibility for the validity of all materials. Neither the authors nor the publishers, nor anyone else associated with this publication, shall be liable for any loss, damage or liability directly or indirectly caused or alleged to be caused by this book. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming and recording, or by any information storage or retrieval system, without ermission in writing from Woodhead Publishing India Pvt. Ltd. The consent of Woodhead Publishing India Pvt. Ltd. does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from Woodhead Publishing India Pvt. Ltd. for such copying. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. Woodhead Publishing India Pvt. Ltd. ISBN: 978-93-85059-16-2 Woodhead Publishing India Pvt. Ltd. e-ISBN: 978-93-85059-71-1

Preface

Producing fabrics using weaving is an ancient art, developed over thousands of years. However, still the people find it difficult to understand the variations and their requirements in fabric manufacturing. It is practically impossible to list all the variations of weaving. In this book an attempt is made to explain the present day practices in organized weaving mills of India engaged in producing fabrics mainly for apparel end use. The purpose of this book is to guide the fresh entrants in to the field aspiring to become technicians who supervise and manage the activities in shop floor. This book deals mainly with the activities involved in manufacturing of grey fabrics, inspection of both grey and finished fabrics, presentation of samples for market, marketing and customer services activities where technical people are involved. The financial aspects, commercial aspects and regulatory requirements are not dealt in this book. The activities of value addition to the fabric by way of wet finishes like bleaching and dyeing, finishing printing, etc. are explained in a separate book. This book does not deal with any technology or design of the machine parts and mechanisms, but explain the methods of monitoring the activities in general. The book deals with the purpose of each process, the activities within the process, the knowledge required to run the process, the control points and check points, the dos and don’ts of the process, normal problems observed in the process, the responsibilities and authorities of supervisors in the process, methods of working out the expected productivity and the workloads, so that the supervisor handling that process can handle it efficiently. The individuals have to study the manuals given by machinery manufacturers, and refer to the systems followed in their company and make their own manual for day to day activities. This book can be taken as a guide. My friends helped me in gathering and compiling the information; especially Mr. Kannan Krishnamurthy in weaving preparation and weaving, Mr. B.A. Sanaki in yarn processing like mercerizing and yarn dyeing. I am very much thankful for the kind support given by them. Woodhead Publishing has always supported me by publishing my books. This is eight books being published by Woodhead Publishing India. I am very much thankful for them.

Contents

Preface iii 1 Activities in a fabric manufacturing unit 1.1 Introduction 2 Cone winding 2.1

1 1 4

Winding

4

2.1.1

Purpose of cone winding

6

2.1.2

What cone winding should do?

7

2.1.3

What cone winding should not do?

8

2.2

General activities in cone winding

8

2.3

Knowledge required for cone winding

9

2.4

Control points and check points

10

2.4.1

Control points in cone winding

10

2.4.2

Check points at cone winding

10

2.5

2.6

Normal problems in winding

13

2.5.1

Improper splicing

13

2.5.2

Electronic Yarn Clearer (EYC) failures

14

2.5.3

Double end

14

2.5.4 Stitches

14

2.5.5

Soft/bulged cones

14

2.5.6

Sunken nose/base

14

2.5.7

Weight variation between cones

14

2.5.8

Shade variation within cones

15

2.5.9

Wrong cone tip or cone label

15

Dos and don’ts for cone winding

15

2.6.1 Dos

15

2.6.2 Don’ts

16

vi

Contents

2.7

Responsibilities of supervisor in winding

17

2.8

Authorities of supervisor in winding

18

2.9

Some hints for better performance

18

2.10 Applicable formulae

18

2.10.1 Method of working out expected production, efficiency and workloads 18 3 Winding–yarn dyeing section

21

3.1 Purpose

21

3.1.1

Purpose of soft winding

21

3.1.2

Purpose of hard winding of dyed yarn

23

3.2

General activities in winding 3.2.1 Soft winding

25 25

3.2.2

25

Hard winding

3.3 Knowledge required for cone winding

25

3.4

Routine activities of winding supervisor

26

3.4.1

Activity specific to soft winding

27

3.4.2

Activities specific to hard winding

27

3.5

3.6

3.7

Control points and check points

28

3.5.1

Control points for soft winding

28

3.5.2.

Check points for soft inding

29

3.5.3

Control points in dyed yarn winding

31

3.5.4

Check points in dyed yarn winding

32

Normal problems

35

3.6.1

Problems in oft winding

35

3.6.2

Problems in dyed yarn winding (hard winding)

35

Dos and Don’ts

36

3.7.1 Dos

36

3.7.2 Don’ts

38

3.8

Responsibilities of supervisor in winding

39

3.9

Authorities of winding supervisor

40

3.10 Some hints for better performance

40



Contents

3.11 Applicable formulae 3.11.1

Working out production and work loads

4 Quest for ideal yarn dye package 4.1

4.2

4.3

4.4

4.5

vii 40 41 44

Winding of soft package for dyeing

44

4.1.1

Crossing or winding angle

44

4.1.2

Winding ratio

45

4.1.3

Package stability

45

The package

45

4.2.1

Package holder (yarn holding tube)

46

4.2.2

SS dye springs

46

4.2.3

Perforated cones

46

4.2.4

Perforated plastic and SS dye tubes

47

4.2.5

Package weight and density

48

Conventional or random winding machines

48

4.3.1

Patterning or ribbon formation and hard edges

49

4.3.2

Hard edge formation

50

4.3.3

Traverse of the package

50

4.3.4

Weight release mechanism

50

4.3.5

Length measuring device

50

4.3.6

Balloon breaker

50

4.3.7

Yarn tension controlling

50

4.3.8

Winding speed

51

Ideal dye package

51

4.4.1

Requirements for a good dye package

51

4.4.2

Dyeing related requirements

51

4.4.3

Requirements from downstream processing and quality control

52

Principles of winding

52

4.5.1

Random winding

52

4.5.2

Precision winding

53

4.5.3

Step-precision winding: (DIGI winding or hybrid winding)

54

viii

Contents

4.5.4

Resulting packages – packages that conform to requirements

54

4.5.5

Packages that do not conform to requirements

55

4.6

Main features of dye package machines

56

4.7

How to calculate the package density?

57

5 HTHP yarn dyeing

59

5.1 Introduction

59

5.2

Purpose of yarn dyeing on HTHP machine

60

5.2.1

What HTHP yarn dyeing should do?

61

5.2.2

What HTHP yarn dyeing should not do?

61

5.3

General activities of Yarn dyeing in HTHP machine

61

5.3.1

Standard operating procedure

62

5.4

Knowledge required for HTHP dyeing

65

5.5

Routine activities of yarn dyeing supervisor

65

5.5.1

66

5.6

5.7

5.8

Activity specific to loading and unloading

Control points and check points

67

5.6.1

Control points for yarn dyeing

67

5.6.2

Check points in arn dyeing

68

Normal problems in yarn dyeing

71

5.7.1

Shade variation within cheeses

71

5.7.2

Shade variation between cheeses

71

5.7.3

Uneven dyeing

72

5.7.4

Stains

72

5.7.5

Improper shade or tonal difference between lots 72

5.7.6

Poor fastness properties

72

5.7.7

Brittle yarn

72

5.7.8

Strength drop after dyeing/bleaching

72

5.7.9

Hard packages after rewinding

73

Dos and don’ts for supervisor

73

5.8.1 Dos

73

5.8.2 Don’ts

74



Contents

5.9

Responsibilities of supervisor in yarn dyeing

ix 75

5.10 Authorities of yarn dyeing supervisor

75

5.11 Some hints for better performance

76

6 Yarn singeing – yarn gassing 6.1

77

Yarn singeing

77

6.1.1

What Singeing should do?

78

6.1.2

What Singeing should not do?

79

6.2

Quality of singeing

79

6.3

General activities in yarn singeing

79

6.4

Knowledge required for singeing

79

6.5

Precautions to be taken for singeing

80

6.6

Control points and check points

80

6.6.1

Control points

80

6.6.2

Check points

81

6.7

Normal problems in yarn singeing

83

6.8

Dos and don’ts for singeing

83

6.8.1 Dos

83

6.8.2 Don’ts

83

Responsibilities of supervisor in singeing

84

6.9

6.10 Authorities of supervisor in singeing

84

6.11 Some hints for better performance

84

7 Yarn mercerising 7.1 Mercerising

7.2

85 85

7.1.1

Changes during mercerising process

86

7.1.2

Concentration, temperature and wet ability of mercerising lye

86

Purpose of yarn mercerising

86

7.2.1

What Mercerising should do?

87

7.2.2

What Mercerisation should not do?

87

7.3

Quality of Mercerising

87

x

Contents

7.4

General activities in yarn mercerising 7.4.1

7.5

7.6

88

Steps involved in one cycle of yarn mercerising 89

Knowledge required for mercerising

91

7.5.1

Significance of different steps in mercerising cycle 91

7.5.2

Precautions to be taken for mercerising

92

Control points and check points

92

7.6.1

Control points

92

7.6.2

Check points

93

7.7

Normal problems in yarn mercerising

95

7.8

Dos and Don’ts for mercerising

95

7.8.1 Dos

95

7.8.2 Don’ts

95

Responsibilities of supervisor in mercerising

95

7.9

7.10 Authorities of supervisor in mercerising

96

7.11 Some hints for better performance

96

8 Space dyeing of yarns 8.1

8.2

97

What is Space dyeing?

97

8.1.1

Warp printing

97

8.1.2

Hank dyeing

97

8.1.3

Space dyeing of cheeses

99

Purpose of space dyeing of yarn

99

8.2.1

What space dyeing should do?

100

8.2.2

What Space dyeing should not do?

100

8.3

Quality of space dyeing

100

8.4

General activities in yarn space dyeing

100

8.5

Knowledge required for space dyeing

103

8.6

8.5.1

Significance of different steps in space dyeing cycle

103

8.5.2

Precautions to be taken for space dyeing

104

Control points and check points

104

8.6.1

Control points

104

8.6.2

Check points

105



xi

Contents

8.7

Normal problems in yarn space dyeing

106

8.8

Dos and don’ts for space dyeing

107

8.8.1 Dos

107

8.8.2 Don’ts

107

8.9 Responsibilities of supervisor in yarn space dyeing

107

8.10 Authorities of supervisor in yarn space dyeing

108

8.11 Some hints for better performance 9 Warping

108 109

9.1

Purpose of warping

109

9.2

Different types of warping

110

9.2.1

Beam warping

110

9.2.2

Sectional warping

111

9.2.3

Draw-warping

111

9.2.4

Ball warping

111

9.2.5

Beam to beam rolling

113

9.3

What warping should do?

114

9.4

What warping should not do?

114

9.5

General activities in warping

115

9.6

Knowledge required for running warping 115

9.7

Control points and check points

116

9.7.1

Control points in warping

116

9.7.2

Check points in warping

117

9.8

Normal problems in warping

119

9.8.1

Variation in tension within and between beams

120

9.8.2

Missing ends

120

9.8.3

Crossed ends

120

9.8.4

Poor quality of beam preparation

120

9.8.5

Production loss due to some cones running out early

121

xii

Contents

9.9

9.8.6

Pattern not proper

121

9.8.7

Lost end

122

9.8.8

Section mark

122

9.8.9

Draw back

122

Dos and don’ts for warping

122

9.9.1 Dos

122

9.9.2 Don’ts

123

9.10 Responsibilities of supervisor in warping

123

9.11 Authorities of supervisor in warping

124

9.12 Some hints for better performance

125

9.13 Applicable formulae

125

9.13.1 Method of working the expected production and the workloads 10 Sizing 10.1 Definition and purpose

125 129 129

10.1.1 Definition of sizing

129

10.1.2 What sizing should do?

130

10.1.3 What sizing should not do?

131

10.2 Quality of sized beam 10.2.1 Performance assessment of sizing is done by

131 132

10.3 General activities in sizing

133

10.4 Knowledge required for sizing

133

10.5 Control points and check points

134

10.5.1 Control points in sizing

134

10.5.2 Check points in sizing

135

10.6 Normal problems in sizing

138

10.6.1 High size pick up

139

10.6.2 Size pick up and fabric weight

139

10.6.3 Low size pick up

139

10.6.4 Uneven size pick up

139



Contents

xiii

10.6.5 Low elongation at break

140

10.6.6 High moisture content

140

10.6.7 Low moisture content

140

10.6.8 Excessive lappers

140

10.7 Dos and don’ts for sizing

140

10.7.1 Dos

141

10.7.2 Don’ts

142

10.8 Responsibilities of supervisor in sizing

143

10.9 Authorities of supervisor in sizing

144

10.10 Some hints for better performance

145

10.11 Applicable formulae

145

11 Basics of fabric structure

146

11.1 Weaves

146

11.2 Plain weave

146

11.2.1

Basic basket weaves

147

11.2.2 Other plain weaves

148

11.3 Twill weave

149

11.4 Satin/sateen weave

150

11.5 Leno weave

151

11.6 Honey comb weaves

152

11.7 Huck a back weaves

152

11.7.1

Waffle weave

153

11.8 Crepe weaves

154

11.9 Dobby fabrics

155

11.10 Jacquard fabrics

155

11.10.1 Types of Jacquard fabric 11.11 Pile fabrics

155 156

11.11.1 Uncut pile

156

11.11.2 Cut pile

156

11.11.3 Different types of cut pile fabric

156

11.12 Double cloth

157

xiv

Contents

12 Drawing-in 12.1 Purpose of drawing-in

158 158

12.1.1 What drawing-in should do?

158

12.1.2 What drawing-in should not do?

159

12.2 General activities in drawing-in

159

12.3 Knowledge required for drawing-in

160

12.4 Control points and check points

160

12.4.1 Control points

160

12.4.2 Check points

160

12.5 Normal problems in drawing-in

162

12.6 Dos and don’ts

163

12.6.1 Dos

163

12.6.2 Don’ts

164

12.7 Responsibilities of supervisor in drawing-in

164

12.8 Authorities of supervisor in drawing-in

165

12.9 Some hints for better performance

165

12.10 Applicable formulae

165

13 Weaving

166

13.1 Definitions and functions

166

13.2 Methods of shedding

168

13.2.1 Tappet shedding

168

13.2.2 Dobby shedding

171

13.2.3 Jacquard shedding

172

13.3 Types of shed 13.3.1 Open shed 13.4 Methods of weft insertion

174 174 177

13.4.1 Shuttle Looms 

178

13.4.2 Projectile looms

179

13.4.3 Rapier (flexible and rigid) technology

181

13.4.4 Jet looms

182

13.5 Multi-phase loom

186

13.6 Multi-axial weaving technology

187



Contents

xv

13.7 Weaving machines with embroidery unit

194

13.8 Multi-axis three dimensional (3D) woven fabric

195

13.8.1 3D orthogonal fabric

195

13.8.2 Multi-axis 3D fabric

197

13.9 Needle weaving technology

198

13.10 Measuring weaving loom shed performance

201

14 Weaving - shuttle looms 14.1 Purpose of shuttle loom shed

203 203

14.1.1 What shuttle loom shed should do?

203

14.1.2 What loom shed should not do?

203

14.2 Quality of loom shed

204

14.3 General activities of a shuttle loom shed

204

14.4 Knowledge required for running shuttle looms

205

14.5 Routine activities of shuttle loom shed supervisor

205

14.6 Control points and check points

207

14.6.1 Control points in loom shed

207

14.6.2 Check points in loom shed

208

14.7 Normal problems in loom shed

214

14.7.1 Yarn related problems

214

14.7.2 Loom related problems

216

14.7.3 Working related problems

221

14.8 Dos and don’ts for weaving

223

14.8.1 Dos

223

14.8.2 Don’ts

223

14.9 Responsibilities of weaving supervisor

224

14.10 Authorities of weaving supervisor

225

14.11 Some hints for better performance

225

14.12 Applicable formulae

225

15 Weaving - shuttle less looms 15.1 Purpose of shuttle less Loom shed 15.1.1 What loom shed should do?

227 227 227

xvi

Contents

15.1.2 What loom shed should not do?

227

15.2 Quality of loom shed

227

15.3 General activities of a loom shed

228

15.4 Knowledge required for running shuttle less looms

229

15.5 Routine activities of loom shed supervisor

229

15.6 Control points and check points

232

15.6.1 Control points in loom shed

232

15.6.2 Check points in loom shed

233

15.7 Normal problems in loom shed

237

15.7.1 Yarn related problems

237

15.7.2 Loom related problems

238

15.7.3 Working related problems

242

15.8 Dos and don’ts for supervisor

245

15.8.1 Dos

245

15.8.2 Don’ts

245

15.9 Responsibilities of weaving supervisor

246

15.10 Authorities of weaving supervisor

247

15.11 Some hints for better performance

247

15.12 Applicable formulae

247

15.12.1 Expected production and work loads 16 Grey fabric inspection 16.1 Purpose

248 250 250

16.1.1 What grey inspection should do?

250

16.1.2 What grey inspection should not do?

250

16.2 General activities in grey inspection

251

16.3 Knowledge required for Fabric inspection

251

16.4 Control points and check points

253

16.4.1 Control points

253

16.4.2 Check points

253

16.5 Normal problems in grey inspection

255



Contents

16.6 Dos and don’ts for fabric inspection

xvii 255

16.6.1 Dos

256

16.6.2 Don’ts

256

16.7 Responsibilities of supervisor in grey inspection

257

16.8 Authorities of supervisor in grey inspection

257

17 Mending of Defects in Fabrics

258

17.1 What is mending?

258

17.2 Mendable and non-mendable defects

259

17.3 Stages of mending

260

17.4 Mending methods for woven fabrics

262

17.5 Mending a sweater

271

17.6 Typical procedure followed in a mill for mending

273

17.7 Care for fancy and special fabrics

274

17.8 Possible mending defects

275

17.9 Methods for removal of stains from fabrics made out of natural fibres

276

18 Final Inspection and packing of fabrics

280

18.1 Introduction

280

18.2 Receiving

280

18.2.1 Dos and don’ts for receiving

281

18.3 Mapping faults and cutting finished fabrics

282

18.3.1 Dos and don’ts for cutting

284

18.4 Good cutting 18.4.1 Dos and don’ts for good cutting 18.5 Book folding 18.5.1 Dos and don’ts for book folding 18.6 Packing 18.6.1 Dos and don’ts for packing 19 Folding of fabrics 19.1 Purpose of folding

285 286 287 289 290 292 294 294

19.2 Hand folding – warkata (वारकाटा) 294

xviii

Contents

19.3 Single folding machine

295

19.4 Double folding machine

296

19.5 Typical procedure for folding

297

19.6 Control points and check points

298

19.6.1 Control points

299

19.6.2 Check points

299

19.7 Dos and don’ts

300

19.7.1 Dos

300

19.7.2 Don’ts

301

20 Fabric Sampling and Presentation

302

20.1 Presentation of samples

302

20.2 Different types of sample presentation

303

20.2.1 Swatch cards

303

20.2.2. Memo samples

307

20.2.3 Sample hangers

310

20.3 Sample cutting machines

314

20.3.1 Manual sample cutting machine

314

20.3.2 Motorised sample cutting machine

315

20.3.3 Waterfall sample cutting machine

317

20.3.4 Slitter – Rewinder

317

20.4 Typical procedure followed for Sample preparation

318

20.5 Control points and check points

321

20.5.1 Control points

321

20.5.2 Check points

321

20.6 Dos and Don’ts

322

20.6.1 Dos

322

20.6.2 Don’ts 21 Textile marketing

323

21.1 What is marketing?

323

21.2 Marketing strategies

323

21.3 Competitive environment in marketing

324



Contents

21.4 Sales management 21.4.1 Distribution channels 21.5 Textile marketing 21.5.1 Marketing grey fabrics to process houses

xix 325 326 329 329

21.5.2 Marketing finished fabrics to garment industry 331 21.5.3 Marketing finished fabrics in retail shops

332

21.5.4 Studying markets and booking orders for fabrics 335 21.5.5 Handling orders 22 Customer Services

336 339

22.1 Importance of Customer Services

339

22.2 Product development

340

22.2.1 Design and development

341

22.2.2 Single package yarn sizing

342

22.2.3 Developing warp sheet using single end warping machine

346

22.2.4 Developing desk loom samples

349

22.2.5 Monitoring the designing activities of yardage 351 22.2.6 Designing activity for bulk designing

352

22.2.7 First piece checking for design

354

22.2.8 Monitoring production hall of product development section

355

22.3 Production planning and control

356

22.3.1 Communicating and monitoring the production schedules

356

22.3.2 Preparing monthly and quarterly production plans and reserving required yarns

359

22.3.3 Production planning and control activity

360

22.4 Quality assurance 22.4.1 Yarn approval

361 361

22.4.2 Measurement of density of soft wound package 362

xx

Contents

22.4.3 Sectional warping inspection

363

22.4.4 Sizing machine inspection

364

22.4.5 Process control in loom shed

365

22.4.6 Greige fabric audit

367

22.5 Market feedback and complaint analysis

368

22.5.1 Handling market complaints and taking actions 368 22.5.2 Handling situation in case of customer order cancellation

374

22.6 Controlling of non-conformance and taking corrective actions

375

22.7 Preventive actions

378

References 380 About the Authour 384

1 Activities in a fabric manufacturing unit

1.1 Introduction The fabrics are made from fibres and yarns by adopting different techniques. Knitting and Weaving are the two major systems adapted for making fabrics using yarns, whereas nonwoven techniques are used for making fabrics directly from fibres. In this book, only the manufacturing of grey fabrics using weaving technique shall be discussed. As told earlier, the raw materials used for making a fabric are yarns. The yarns are made into two groups, viz. warp and weft. The yarn which runs along the line of the fabric is termed as warp and the one that goes across the fabric is weft. The yarns may be single, double or multi-fold depending on the requirement of the fabric. The yarns used might be in grey form or processed one like bleached, mercerized, singed, dyed, spaced dyed, printed, etc., depending on the end use. The yarns received from spinning, doubling or processing are first converted into cones of required dimensions having specified length of yarn wound with uniform tension. The cones are made into two parts, one for warp and the other for weft. The warp yarns are wound onto a warp beam either by using a beam warping machine or a sectional warping machine. The sectional warping is used normally where dyed yarns are used for various patterns in the fabric, or in the case of doubled or multi-fold yarns where sizing is not required. The yarns going for warp needs good strength and elasticity. Hence in case of single yarns in warp, they are invariably sized, whereas in case of double yarns, depending on the situation, decision for sizing is taken. The warp yarns are drawn into reed and healds depending on the weave and the pattern. The weft yarn is wound on pirns in case of shuttle looms, whereas for shuttle less looms, the wefts are supplied on large cones. Figure 1.1 illustrates the processes involved from yarn manufacture to fabric manufacture. Depending on the requirement of the customers and the type of machine used, the processes adopted are different. There are number of permutations and combinations. The technician has to plan and decide on the processes required for a particular requirement of the fabric.

2

Handbook on Fabric Manufacture

Grey Yarn from Open end spinning – Rotor, Jet spinning etc.

Yarn Processing – Bleaching, Mercerizing, Dyeing etc.

Reeling on Hanks

Winding on soft packages

Winding on cones

Grey Yarn from Ring spinning

Winding on hard packages

Sectional warping

Beam warping

Pirn winding for shuttle looms

Direct weft

Sizing

Drawing-in

Weaving – Shuttle less looms

Weaving – Shuttle looms

, Grey Fabric inspection mending and packing

Value adding Processes for fabrics

Processed Fabric inspection, mending and packing

Figure 1.1 Process in fabric manufacturing

The grey fabrics from loom cannot be used directly for apparels. They undergo various processes like desizing, scouring, bleaching, dyeing, printing, finishing etc., depending on the requirement of the customer and of the end product. Some of the processes are by means of chemical treatments whereas some might not use any chemicals. Majority of them use water, whereas some neither use water nor chemicals; but use some mechanical means. All these processes add value to the fabrics and hence can be termed



Activities in a fabric manufacturing unit

3

as “Value Addition Processes for Fabrics.” These processes shall be dealt separately in a different book. In forthcoming chapters let us try to understand the purposes of each processes, the controls to be exercised to get the results, the normal problems or nonconformities and the actions needed. We shall also discuss on some aspects of preparing samples for marketing, product designing, production planning, quality assurance and marketing aspects relating to grey fabrics.

2 Cone winding

2.1 Winding Winding is the process of transferring yarn or thread from one type of package to another to facilitate subsequent processing. The yarn from ring frame cops are transferred to big cone or yarns from a badly wound cone is rewound on a new cone. The rehandling of yarn is an integral part of the textile industries. The package and the yarn should be suitable for processing on the next machine in the production process, and also other factors such as packing cases, pressure due to winding tension, etc., must be considered. Basically, there are two types of winding machines: Precision winders and drum winders or non precision winding. Precision winders, used primarily for filament yarn, have a traverse driven by a cam that is synchronised with the spindle and produce packages with a diamond-patterned wind. By precision winding successive coils of yarn are laid close together in a parallel or near parallel manner. By this process it is possible to produce very dense package with maximum amount of yarn stored in a given volume. Features of precision winding are as follows. • Package are wound with a reciprocating traverse. • Patterning and rubbing causes damage of packages. • Package contains more yarn. • Package is less stable. • The package is hard and compact. • The package is dense. • Rate of unwinding of package is low and the process of unwinding is hard. • The unwound coil is arranged in a parallel or near parallel manner. Non precision winders, namely, drum winders are used principally for spun yarns; the package is driven by frictional contact between the surface of the package and the drum. By this type of winding, package is formed by a single thread which is laid on the package at appreciable helix angle so that the layers cross one another and give stability to the package. The packages



Cone winding

5

formed by this type of winding are less dense but is more stable. The features of non-precision winders are as follows. Only one coil is used to make this packages. • Cross winding technique is used. • The package density is low. • Minimum number of yarn is wound. • The package formed is soft and less compact. • The stability is high. • Flanges are not required. • The rate of unwinding is high and the process is easy. • The packages formed have low density. The drum winders are invariably used in cotton and spun blended yarn winding. The yarns pass through tensioners which control tension of winding, pass through waxing where needed and then through yarn clearers before getting wound on to a paper cone. The yarn clearers may be mechanical or electronic in nature. The traverse is guided by a rotating groved drum. The surface speed of the grooved drum is considered as speed of winding for calculating the efficiency (Figure 2.1).

Package

Rotating grooved drum

Clearer Waxing Unit Tension system

Yarn to be wound

Figure 2.1 Cone winding using grooved drum

The winding machines can be of manual type or automatic type. In manual winding machines, normally a single shaft contains number of drums and hence all packages are driven at a time. All activities like creeling, taking the yarn through the tensioners and guides, knotting the yarn, doffing the full cones, etc., are done manually. The automatic cone winding machines come with different configurations. For feeding ring cops magazines may be provided for individual drums or a common hopper for the complete machine.

Author: Please check the citations of Figures 2.1–2.3 and correct if necessary.

6

Handbook on Fabric Manufacture

For joining ends either knotters or splicers are used. They may be provided for individual drums or for a group of five, ten or more drums. Doffing may be automatic or manual as per need. Attachment of length measuring units are optional. Electronic yarn clearers with versatile setting, inverter drive for individual drums, are normal features. The winding speeds can go up to 2000 m/min in modern automatic winders, whereas with manual winders, maximum speed attainable is 750 m/min. Link-coner is a combination of Ring frame with auto doffing and an automatic winding unit. This reduces the material handling, accumulation of ring spun yarn and avoids mix ups. Where link-coners are installed, they come under the control of Ring frame section (Figures 2.2 and 2.3).

Precision winding

Non-precision winding

Figure 2.2 Precision and non-precision winding

2.1.1

Purpose of cone winding

The ring spun yarn package dimensions are limited by the lift and ring diameters; hence they have shorter lengths. Further, the tensions of winding vary both within and between bobbins. Uneven tensions in the yarns lead to poor working in warping, sizing, pirn winding and weft unwinding on looms and leads to unstable fabric. The ring frame cops cannot be used directly for either making warp sheet or as weft because of the short comings explained. Hence it is needed to wind them on to a large package with uniform tension. Due to various reasons, the ring spun yarns can have various faults, which need to be cleared before making a fabric. The faults, if not cleared, can result in breaks during weaving and also produce damages in the fabric. Hence the purpose of cone winding is to clear the yarn from objectionable faults and wind with uniform tension on large packages like cones or cheeses



Cone winding

Manual winding machine

Automatic winding machine with individual magazines

Automatic winding machine with common hopper feed

Link coner

7

Figure 2.3 Different cone winding machines

to facilitate the activities of warping and weaving, and for easy handling for transporting.

2.1.2

What cone winding should do?

Winding should ensure the following. a. Clear the yarns from objectionable faults which hinder the process of warping, weaving and knitting and can lead to a faulty fabric. b. Wind yarns with uniform tension so that the yarns unwind uniformly in warping, weaving and other processes. c. Wind yarns of required length on cones or cheeses so as to have minimum remnants while working on warping. d. Empty the spinners’ bobbins so that they can be used again. e. Build suitable and stable packages for easy transportation within a mill or to an outside factory.

8

Handbook on Fabric Manufacture

f. Provide clear identification on cones/cheeses to identify the material, type of yarn, lot, count, the winding machine and drum used.

2.1.3

What cone winding should not do?

a. Should not cut unobjectionable faults and create problems of knots or bad splices. Cutting of unobjectionable faults lead not only to a lower efficiency at winding but also to a yarn with more weak spots due to splicing or objectionable faults due to knots. b. Should not increase hairiness. If the surface of machine parts which comes in contact with running yarn is rough the hairiness shall increase. c. Should not develop winding faults like bunches, snarls, ribbon, stitches, sunken nose, etc., which can create problem in further processes. The winding faults can result in breakdowns of machine parts like reeds, drop pins, healds and needles and also smashes in fabrics. d. Should not mix up different counts or different lots of yarns. Any mix up shall result in an undesired fabric and complete fabric shall have to be rejected.

2.2

General activities in cone winding

Following are the general activities in cone winding section meant for weaving preparation. a. Getting programme from user departments for the yarns required for them in terms of the material, count, lot numbers, quantity, cone weights and number of cones. b. Informing spinning section regarding the yarn requirement and getting the ring frame yarns for winding. c. Allocating different winding machines and drums for winding as per production requirement. d. Setting the yarn clearers considering the quality requirements and the actual quality of yarn received. e. Setting the tension unit and waxing units as required. f. Setting the machine speed considering the count and strength of yarn being wound. g. Selecting the empty cones with agreed colour codes. h. Winding the yarn on large cones with predetermined length and tension.



Cone winding

9

i. Mending the breaks and cops run outs with suitable splicing or knotting as needed. j. Doffing full cones and sending them to the next process or packing them and keeping in warehouse as the case may be. k. Cleaning the remnant ring frames cops and sending the empty cops to ring frames.

2.3

Knowledge required for cone winding

The technicians and the people working in winding section need to have the following knowledge. a. Importance and functions of machines, mechanisms and infrastructure in the section. b. Critical quality requirements of the cones depending on the end use like warp or weft, base yarn or pile yarn in case of warp, the fabrics going for single shades or for designs with woven or printed patterns, the type of machines used in warping like high speed warping, slow speed warping, pirn winding or soft package winding and so on. c. Setting electronic yarn clearers, splicers, tensioners as per the yarn count, quality requirements and the fibres in use. d. Knowledge about cone angles, cone dimensions, cone quality requirements and selection of cone holders and drums to suit the requirements. e. Production planning and balancing the machines depending on the spinning doffs in stock and spinning productions expected in the shift. f. Calculation of production and efficiency, the industry norms and factors affecting productivity. g. Role of humidity and temperature in maintaining quality and productivity considering the materials being worked, h. Workloads, work allocation and standard working conditions appropriate to the section. i. Standard operating procedures and work instructions depending on the machines, materials and quality requirements. j. Colour codification and its importance. k. Precautions to be taken while working. l. Importance of cleanliness and personal safety. m. Safety gadgets used in the factory and the workplace.

10

Handbook on Fabric Manufacture

2.4

Control points and check points

It is essential to have clarity on the points to be controlled to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own “Control Points and Check Points” and display them in the work area so that the people can follow. The supervisors should religiously follow the instructions given as control points and check points.

2.4.1

Control points in cone winding

a. Selection of suitable process parameter considering the material, the next process and customer requirements. The parameters to be controlled are generally speeds, yarn clearer settings, tension, cone dimensions, length of yarn in cone, wax quality and settings at contamination channel. b. Cone identifications: viz. Colour of plastic cones, cone tip in case of paper cones, cone label, winder no. machine no, lot no. contract no. c. Engagement of trained workmen for different jobs and for different types of winding machines. d. Evolving maintenance schedules and activities, and implementing them. e. Deciding the work allocation and production targets.

2.4.2

Check points at cone winding

Material related a. Materials brought for winding (count, mixing, blend, etc.) and the critical quality requirements. b. Spinning doff stocks in different counts, expected production in different counts for the shift and winder allocation. c. Cones required in each lot to complete packing. d. Doff lables on the cops/crates, date and shift of spinning, the ring frame number. Following first-in-first-out system is very important within a given mixing and count to avoid various problems like barre, shade variations and so on. e. Whether the identification given for cops is as decided and agreed? Winding machine related a. Condition of machine parts viz. drums, cone holders, tension units, porcelain guides, suction units, air valves, air pipes, conveyor belts,



Cone winding

b. c. d. e. f. g. h. i. j.

11

splicing/knotting units, doffing units, empty cone reserve, creel magazine, etc. Working of all stop motions. The tension applied for the yarn quality and uniformity of tension on all production positions. Application of wax and proper working of all waxing units wherever waxing is a requirement. The quality, shape and size of wax discs running. Condition and cleanliness of the yarn path and the machine. Alignment of the creel pegs and the yarn guides. Setting of the cone holders. Check for proper revolving of the magazines and feeding the cops exactly in place. Free movement of the conveyors.

Setting related a. The settings required and done as per the yarn quality requirement namely count, slubs, long thick, long thin, count mix, length taken out for splicing, contamination channel, etc. b. The speeds recommended and the actuals. c. Application of the tension as per yarn quality. d. Suitability of the prisms used in splicer for the count and materials. e. The settings of splicer as per the yarn quality. f. The length set as per requirement and uniformity on all drums. Performance related a. Clearing efficiency of yarn clearers. b. Production efficiency of each drum in automatic winders. c. Winding drum-wise performance, i.e. breakages, cop rejections, cuts, stoppages and production. d. Winder-wise production and wastes generated in manual winding. e. Cone quality. f. Weight variations between cones. g. Hard wastes generated and the reasons. h. Splicing quality – strength, appearance and dimensions. i. Friction value for waxed yarns.

12

Handbook on Fabric Manufacture

j. Cone hardness. k. Increase in hairiness and imperfections after winding. Documentation related a. Check whether the cone labels are entered with all relevant information on all cones. b. Check and verify the cone weights for uniformity and as per calculation and the length set. c. Proper entering of data of each winding machine in the records. d. Check whether the cones were sent to next process/packing with proper memo and documentation. e. Verify whether the remnant cops are counted/weighed, recorded and returned to spinning with proper memo. Work practice related a. Check whether the workers are briefed on the standard operating procedures and relevant work instructions. b. Following the material handling systems as per requirements. c. Winders putting the correct type of knot while mending breaks in case of manual winders. d. Removing of unused materials in time from time to time. e. Cleanliness of the machines and surroundings area all the time. f. Workers using the spinning doffs with the machine traceability in view. g. Removing of the hard wastes from time to time from suction box. h. Whether the workers are wearing waste bags and collecting the defective cops, cleaning them and putting back for winding? i. Whether the cleaned cops are put back randomly or fed to the nearest drum? Log book related Check whether the following information are entered in the log book. a. The machines allotted for different counts and lots, the number of drums allotted, the colour codification and cone identification used, the lot completion details, the cone weights required, the winders engaged and the production of each winder, the doff stock at the end of the shift. b. Stoppages with reasons for stoppages. c. The problems faced like short of materials, materials not received in time, breakages, and quality related issues.



Cone winding

13

Management information system related Check for the correct entry of following data in the system. a. Lot number and contract number. b. Count and type of material. c. Winding machine no. d. No of drums. e. Winder number. f. Productions – winder wise and machine wise. g. Average weight of cones and total cones. h. Date and time of production. i. Date and time of issue to next process/packing. j. Remnants returned to spinning. k. Colour codification used. General a. b. c. d. e. f.

Maintaining the temperature and humidity as per requirement. The quantity of hard wastes generated. Whether the hard wastes generated are within the norms? Proper cleaning of the machine by the maintenance people. Whether the paper/plastic cones used are of required quality? Whether the required paper/plastic cones are brought for the next shift and handed over. g. Whether you received the shift in a good condition? h. How was the condition of your section when you handed over the shift to next person?

2.5

Normal problems in winding

Some of the normal problems in winding are Improper Splicing, Electronic Yarn Clearer (EYC) failures, Double end, Stitches, Soft/Bulged cones, Sunken Nose/base, Weight variation between cones, Shade variation within cones and Wrong Cone Tip and Label.

2.5.1

Improper splicing

Normally spinning mills run different counts on the same winding machine, but are not be able to match the prism size, the air pressures, timing, etc., required for the yarn. This results in improper splicing. The problem is more

14

Handbook on Fabric Manufacture

in coarse counts. Low air pressure, improper mingling chamber and improper setting for opening and splicing are other reasons for improper splicing.

2.5.2

Electronic Yarn Clearer (EYC) failures

Normal reasons for EYC failures are Fluff accumulation in the measuring slot, Low input voltage, Blunt cutters, Jammed cutters, and loose fitting of PCB. Checking of each EYC by the winders before starting the work in the shift is recommended to avoid the problem.

2.5.3

Double end

When an end is still running in winding the cop is removed and new cop is put and another end is taken up and joined, double ends are formed on the cone. Failure of EKP (Electronic Knotter Programmer) in cutting the end after a splice or a knot, and failure of bobbin conveyor belt are the main reasons for double ends found on cones.

2.5.4

Stitches

Variation in cone holder settings, vibrations in cone holder/drum, and damaged drums are the normal reasons for stitches. The static electricity generated during winding, especially creates stitches in manmade fibre yarn winding, which are prone for static charges.

2.5.5

Soft/bulged cones

Normal reasons for soft or bulged cones are very low tension, yarn going out of the tension disc, fluff accumulation between tension discs, and improper rotation of tension discs.

2.5.6

Sunken nose/base

The main reasons for the sunken nose or base are improper fitting of paper cones on cone holder, improper size of paper cones, and improper setting of cone holder.

2.5.7

Weight variation between cones

The normal reasons for weight variation between cones are variations in tensions between drums, improper setting of either conometer or diameter on cones, malfunctioning of drum sensor and too much variation in yarn count.



Cone winding

2.5.8

15

Shade variation within cones

The normal reasons for shade variations within cone are mix up of yarn from different mixing, variation in day to day mixing preparation and addition of soft wastes, ring cut or abrasion of yarn polishing a part of yarn, very slack tape resulting in a very low TPI in spinning, contamination of oil or grease while spinning, and exposing the ring cops to smoke or fumes.

2.5.9

Wrong cone tip or cone label

It is normal practice that empty cones and cone labels are brought in advance and labels are pasted to the empty cones before winding yarn on it and kept it in cone magazine. Sometimes, there shall be a change in programme and different count is started on the same drums. In such cases, if the winder does not remove all the spare empty cones from the machine, some cones might be with wrong cone tip and cone identification label. The empty cone and the label to be used on a machine are indicated to all by hanging a specimen cone. Sometimes, when a count is changed, the specimen cone and label are not updated on winding machine, and hence wrong cone tips and labels may be used.

2.6

Dos and don’ts for cone winding

Understand clearly what you are supposed to do without fail and what you should not do at any cost in cone winding. Some examples of dos and don’ts are given below.

2.6.1

Dos

a. Verify and understand the cone quality requirements before starting your work. b. Get clarity regarding the number of cones to be produced and weight required for each cone. c. Verify the calculations and assumptions before implementing. d. Stick to colour codes and other identification system agreed between sections. e. Work for getting maximum utilisation and efficiency for which men are engaged. f. Have control on generation of hard wastes. g. Check personally rather than depending on a third person whenever a problem is referred to you.

16

Handbook on Fabric Manufacture

h. Check the grey yarn lot running. i. Check the visual quality of cones produced. j. Check the settings at electronic yarn clearers. k. Check the cleanliness of the machine. l. Check the tension and uniformity in tension. m. Check the working of waxing in case of wax being used. n. Decide on the length to be set after considering allowances for wastes and slippage. o. Check the length set and compare with the standard. p. Check the speed set. q. Check the production to be taken out in the lot. r. Confirm that the yarn is approved by Quality Assurance section (Q.A) before it is brought to winding. s. Check the available quantity of yarn in winding and the yarn required for completing the lot before bringing fresh yarn. t. Check the details written in display boards. u. Take the stock of yarn at the end of each shift and hand it over to next shift supervisor. v. Discuss with the packing/warping in-charge before taking any yarn for winding. w. Make trail on five drums before finalising parameters on all drums. x. Keep only those materials that are required for working in the shift. y. Always insist on wearing waist bag and collecting all hard wastes in the bag. z. Hand over the machines and the winding section to next shift in a clean condition.

2.6.2

Don’ts

a. Do not decide on colour code by yourself, but discuss with the users and suppliers. b. Do not draw more yarn from spinning or produce more cones than the ordered quantity. c. Do not increase speeds or the weight of packages to get more productions. d. Do not engage people in the shift unless you have confirmed orders. e. Do not start the machine if the yarn received is not as per the plan given.



Cone winding

17

f. Do not use broken plastic cones for winding yarn. g. Do not run the drum which is not giving the required cone quality. h. Do not start winding if the lot numbers are not matching to order. i. Do not accept the yarn if colour code used are not as per requirement. j. Do not run coarse counts by the side of fine counts. k. Do not allow to clean the machine with compressed air while working. l. Do not allow anyone to use compressed air for cleaning self. m. Do not allow using of loose hard wastes for cleaning the machines. n. Do not allow wearing of loose cloths while working on the machines.

2.7

Responsibilities of supervisor in winding 1. Completing the assigned jobs and achieving the production with quality as agreed upon besides maintaining the discipline, housekeeping and team working. 2. Ensuring that all the programmed machines are kept working. 3. Getting the machines started in time and achieving maximum utilisation. 4. Responsible for ensuring clean working area all the time and all materials and records are kept in their respective place. 5. Verifying the yarn lot number before taking yarns for winding. 6. Checking and adhering to the colour codes as decided. 7. Taking corrective actions like getting the settings corrected, getting the cones rewound, while limiting him to the authorities given to him. 8. Getting the collected hard wastes put in designated places and disposed after documenting. 9. Ensuring safe handling of the cones and preventing hard wastes due to poor handling practices. 10. Supplying cones in time to user department/packing. 11. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline. 12. To report HRD in case of any accidents and filling the accident reports in time. 13. To help winding in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.

18

Handbook on Fabric Manufacture

2.8

Authorities of supervisor in winding

a. Questioning the jobber and workers when the work done is not satisfactory. b. Sending memo to HRD in case of serious lapse in discipline by any of the employee working under him. c. Allotting or change jobs to winders and other workers considering their skills. d. Arranging for rewinding of the cones in case of winding defects and informing higher authorities regarding the quantity and the reasons for rewinding. e. Recommending leave and/or permission to the subordinates in the section. f. Stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions.

2.9

Some hints for better performance

a. Always keep the winding area clean. b. Do not bring more yarn from spinning and keep in stock at winding section. c. Observe for repeated breaks in drums and attend the electronic yarn clearer. d. Keep the idle drums at lowest possible level.

2.10

Applicable formulae

Yarn clearing ( Faults present in yarn fed − Faults in cleared yarn ) × 100 = efficiency % Faults present in yarn fed

Production per Winding speed in Y.P.M × No of minutes in shift × Efficiency % = drum in Kgs Count Ne × 840 × 2.2 × 100

2.10.1 Method of working out expected production, efficiency and workloads Following table explains the method of working out expected production in winding and drums that could be allotted to a winder.



Cone winding

19

Sr. No

Activity and time for each activity

A

To take charge from previous technicians in minutes

B

To receive instruction from shift in charge in minutes

Ca

Resultant count worked – Ne

Cb

No of drums allotted

Cc

Speed MPM

Cd

Final Package weight Gms

Ce

Supply Package weight in Gms

Cf

Length of yarn per supply cone = Ca × 840 × Ce)/(453.4 × 1.08)

Cg

Number of supply cones per one final cone = Cd/Ce

C

Time to run one supply cone in minutes = Cf/Cc

D

Placing the cones at bottom and piecing in minutes

Ea

Breaks per cone

Eb

Time to mend one break in minutes

E

Time to mend break per cone (Ea * Eb)

F

Time for building one cone = Cg × (C + D + E)

G

Time for writing yarn details on sticker

H

Time for putting stickers on machine

I

Time for putting stickers on cone

J

Time to fix empty cone on drum

K

Time for Wrapping yarn end to the empty cone

L

Time to remove cone in minutes

M

Time for putting a cone in basket in minutes

N

Total operating time per one cone building in minutes = Cg × (C + D + E) + (F + G + H + I + J + K + L + M)

O

Number of working minutes in a shift

P

No of cones per drum at 100% machine working (Number of doffs) = (O/N)

Q

Expected production per drum in Gms

20

Handbook on Fabric Manufacture

Sr. No

Activity and time for each activity

R

Work load per cone = Cg × (D + E + G + H + I + J + K + L + M + N)

S

Variable work load per drum = (R × Q)

T

Number of minutes at 75% workload per shift

U

Fixed work load

V

Drums that could be allotted per winder = (T − U)/Q

W

Suggested drums per winder

X

100% production per drum in Gms = (Cc × 480 × 453.4)/(1.08 × 840 × Ca)

Y

Efficiency at full working = (Q × 100/X)

Z

Expected efficiency after deducting time for taking charge, instructions and for patrolling at 120 min)

3 Winding–yarn dyeing section

3.1 Purpose In yarn dyeing of packages there shall be two winding sections, one before dyeing and another after dyeing. Soft cheeses are wound before dyeing whereas hard packages are wound after dyeing. In case of hank dyeing, there shall be one process of reeling before dyeing and a process of hank to cone winding after dyeing. The purposes are different for soft winding and hard winding. Let us understand them (Figure 3.1).

Grey yarn cones

Soft winding

Cones ready for warping and weaving

Soft packages loaded on carrier

Yarn dyeing

Hard winding

Dyed yarn taken out from dyeing

Figure 3.1 Processes of winding for dyed yarns

3.1.1

Purpose of soft winding

• The main purpose of soft winding is to loosely wind yarn on perforated tubes with uniform density to facilitate dyeing on high

22

Handbook on Fabric Manufacture

temperature high pressure package dyeing machine. The quality requirements of soft wound packages are discussed in detail in next chapter (Figures 3.2 and 3.3).

Figure 3.2 Soft winding

Soft packages are loaded on spindles and locked at the top

Figure 3.3 Carriers of HTHP yarn dyeing machine

• It is necessary to maintain the cheese dimensions with required weight (package density) to suit the requirement of dyeing. The cheese diameter is decided by the gaps between spindles in the carrier of a dyeing machine.



Winding–yarn dyeing section

23

What soft winding should do? a. Producing soft wound cheeses on perforated tubes/springs of required count as per the yarn dyeing programme. b. Keeping the soft wound cheeses in pegged trolleys and avoiding the deformation of cheese by handling. c. Ensuring zero breakages while winding yarn on soft packages. d. Providing suitable identification for the count of yarn being wound in discussions with yarn dyeing section. e. Keeping a track on the quantity of yarn drawn for soft winding, yarns wound on cheeses and yarns left in stock. What soft winding should not do? a. Soft winding should not wind more yarn than required for dyeing and keep soft packages in stock. By producing more soft packages than required and keeping them in stock make the cheeses more soft which can result in uneven dyeing or increase in wastes. b. Keeping cheeses in baskets or crates damages the layers and results in more wastes. The soft packages should be kept in pegged trolleys so that no cheese shall touch another cheeses, and also no one touches the body of the cheese while handling or transporting. c. Soft winding should not aim for clearing yarn faults while winding as the breakages and piecing can lead to uneven density of packages leading to uneven dyeing within packages and between packages.

3.1.2

Purpose of hard winding of dyed yarn

The purpose of hard winding is to wind the dyed yarn of required length on cones with application of suitable lubrication like wax and uniform tension to make it suitable for warping, knitting and weaving operations. In case the yarn is dyed in loose form, the hanks need to be rewound on cones using a hank to cone winding machine (Figures 3.4 and 3.5). What hard winding should do? a. The hard winding should wind yarns of required length on cones by taking instructions from warping and produce the exact number of cones in each shade as required by the design. The lengths and number of cones in each shade are decided by warping section depending on the design and the order quantity. b. Winding the yarn with uniform tension and ensuring proper density of wound yarn cone is an essential activity of hard winding.

24

Handbook on Fabric Manufacture Delivery package

Grooved drum Waxing unit Tension unit

Feed package

Figure 3.4 Dyed yarn winding machine

Figure 3.5 Hank to cone winding machine

c. The inner portion of the cheese shall have a slightly different depth of shade, and hence remove the shade variation portion from the inner portion of the cheeses while running them out. d. Apply suitable lubricant like wax to the yarn and make it pliable and free from hairiness. What hard winding should not do? a. Should not produce cones with different lengths than specified. b. Should not produce cones with very high density (hard cones). c. Should not produce cones with bunches and ribbons. d. Should not produce more wastes than estimated and agreed.



Winding–yarn dyeing section

3.2

General activities in winding

3.2.1

Soft winding

25

a. Getting programme from yarn dyeing and accordingly preparing soft wound packages. b. Getting grey yarn from yarn godown or cone winding section as per the requirement of dyeing section. c. Setting the winding machines (speed, tension and length) to run the yarn depending on the count of yarn. d. Winding the yarn on perforated tubes or on collapsible springs. e. Fixing tie yarns of specific colours and materials as indicator of the count. f. Supplying the soft packages to dyeing by putting them on pegged trolleys.

3.2.2

Hard winding

a. Getting instructions from warping and/or weaving regarding the weight and number of cones required in different shades and counts. b. Getting the dyed yarn on dye packages. c. Setting the winding machines as required for the count and length of cones. d. Getting instructions for shade cutting from quality control section or the supervisor and cutting the yarn on cheese. e. Winding the yarn on cones. f. Putting the count label and sending the cones to next process through yarn godown. g. Keeping records of hard wound cones produced and delivered design wise.

3.3 Knowledge required for cone winding People handling winding section should have knowledge of the following. a. Importance and functions of various winding machines, mechanisms and infrastructure in the section. Unless one understands the machines and mechanisms available with him, he cannot produce the results as required. b. Setting tensioners as per the yarn strength, the quality requirements and the fibres in use.

26

Handbook on Fabric Manufacture

c. Waxing and its importance. There are different types of waxes available, and one should know which wax is suitable for the materials and working conditions. d. Knowledge about cone angles, cone dimensions, cone quality requirements and selection of cone holders and drums to suit the requirements. e. Production planning and balancing of winding drums to suit the production requirements. f. Workloads, work allocation and standard working conditions appropriate to the section. g. Calculation of production and efficiency, the industry norms and factors affecting productivity. h. Colour codification and its importance. i. Precautions to be taken while working soft packages and dyed yarns. j. Importance of cleanliness and personal safety.

3.4

Routine activities of winding supervisor

a. Taking charge from the previous shift supervisor regarding the machines working, material and lots working, problems faced, pending works and specific instructions and getting a general feel of the problems encountered and being encountered in both soft winding and hard winding areas. b. Understanding the production plan, production efficiency being achieved and allocating the drums/machines for different activities as per the priorities of warping and dyeing departments by coordinating with them. c. Coordinating with yarn godown and getting the required yarns as per plan. d. Allocation of workmen on the machines considering their skills and capabilities. e. Counselling the workers and motivating them for attending the work regularly and doing the work efficiently. f. Taking repeated rounds in the work area and understanding the actual position of materials being worked and the problems being faced on a continuous basis. g. Coordinating with electrical and mechanical sections relating to problems in the machinery and the working area, and getting them attended.



Winding–yarn dyeing section

27

h. Ensuring that the machine parameters are set as required, viz. the speed, length, tension, and setting of waxing unit. i. Ensuring that the condition of the machine is maintained for getting the quality and production as needed. j. Ensuring that the empty/remnant cones removed from the creel are kept in designated place and sent to concerned area. k. Ensuring that all safety gadgets are utilised properly all the time for operating the machines and while transporting the materials. l. Ensuring that the hard wastes collected are disposed to waste section with proper identification and recording. m. Recording the stoppages of each machine reason wise and working out the production loss due to stoppages. n. Recording the activities in a log book giving details of machines worked, counts allotted, number of people engaged, production achieved, problems faced and productions to be achieved in each order, stock of feeding material, stoppages and special instructions. o. Reporting the activities to winding in-charge highlighting the problems faced, actions taken, present situation, and getting instructions for further actions.

3.4.1

Activity specific to soft winding

1. Getting the cartons opened and ensuring proper disposal of the old carton in the specified area of scrap or reused for packing the wound yarn as per instructions. 2. Verifying the quality of cheeses produced by randomly checking the dimensions, weight, visual appearance, labels, colour codification and markings. 3. Ensuring that the old cartons and the paper cones are collected, packed and sent to scrap section with memo. 4. Checking the stock of empty plastic tubes and ensuring that the empty tubes are got from yarn godown/hard winding in time so that the winding machines do not wait for empty cones.

3.4.2

Activities specific to hard winding

1. Getting empty plastic/paper cones from yarn godown/stores. 2. Returning the run out plastic perforated tubes to yarn godown/soft winding with proper accounting.

28

Handbook on Fabric Manufacture

3. Verifying the stock of cones in each shade for the design and working out the requirement of winding drums and winders. 4. Verifying the quality of cones produced by randomly checking the dimensions, weight, visual appearance, labels, colour codification and markings. 5. Ensuring the delivery of wound cones to the warping or weaving through yarn godown in time as per plan. 6. Maintaining sample book with samples of all the lots worked (shade cards).

3.5

Control points and check points

In any process it is essential to have clarity on the points to be controlled to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own “Control Points and Check Points” and display them in the work area so that the supervisors refer and follow. The control points and check points shall be different for soft winding and hard winding and also shall vary depending on the count and shade in hand and the design requirements. Following are some general examples (Figure 3.6).

Figure 3.6 Perforated tube and identification band

3.5.1

Control points for soft winding

a. The count and type of yarns, number of soft packages to be prepared for the design in hand, the deadline for giving wound material. b. The package dimensions required depending on the cheese holding capacity in dyeing machine, i.e. the traverse and maximum diameter.



Winding–yarn dyeing section

29

c. The soft package density required i.e. the weight of each soft package for the diameter and traverse (grams per litre) d. Type of dye package tube, i.e. perforated plastic, perforated metallic tubes or collapsible steel tubes/springs. e. The identification threads/bands to be put on soft wound packages. f. Instructions to be given to winders. g. Engagement of skilled employees. h. Deciding of work norms and allocation of workmen. i. Designing maintenance activities and implementing them. j. The information to be entered in the log book and data to be given to Management Information System.

3.5.2.

Check points for soft inding

Material related a. Whether the yarns received are as per the indent and design requirements? b. Whether the cones are good in shape and have uniform hardness? c. Whether all the yarn given in a lot belongs to same source of supply or not? Winding machine related a. Whether the running drums are in good condition? b. Whether the stop motions are functioning properly? c. Whether the length counters are working normal? d. Whether the tensioners are in good condition? e. Whether the tension discs are coded suitably depending on their weights. f. Whether the quality of dye tubes and their fitting in the cheese holder is okay? Setting related a. Whether the tension set is as per the count and strength of yarn? b. Whether the tension discs on all drums are uniform for the count being worked? c. Whether the speed set is as per norms? d. Whether the speed set on all drums are uniform and as planned? e. Whether the length set on all drums are uniform?

30

Handbook on Fabric Manufacture

f. Whether the length set gives the required weight as per the count of the yarn? g. Whether the required weight of package is obtained for the diameter decided? Performance related a. Whether the breakages are within limits. b. Soft package density and dimensions. Check for variations between cheeses. c. Lot wise/design wise productions completed and cheese further required in each lot. d. Production efficiency. e. Winding machine wise performance. f. Winding drum-wise performance. g. Winder-wise production and wastes generated. Work practice related a. Whether the stop motions are kept functioning properly? b. Whether winders are putting correct type of knots? c. Whether the workers are following the material coding systems as per requirements? d. Whether the machines and surroundings are kept clean? e. Whether all winders are putting hard wastes in the designated place or not? Documentation and records a. Whether the productions are recorded against each winder or not? b. Whether winding drum wise productions are monitored? c. Whether the soft packages are sent to next process with proper memo and documentation? d. Whether production data are entered in system in time or not? Waste monitoring a. What is the quantity of hard wastes generated? b. Whether the hard wastes generated are within the norms? c. Whether the wastes are monitored machine wise or not? d. Whether the wastes are weighed, labelled and recorded before sending it to waste section?



Winding–yarn dyeing section

31

Log book related Check whether the required information are entered in the log book like: a. The number of machines working count wise. b. The men engaged machine wise and drums wise. c. The production achieved machine wise, count wise. d. The hard wastes generated machine wise. e. The reason wise stoppages of the drums and machines. f. The problems faced and the actions taken. g. The stock of empty plastic tubes (colour wise). h. Stock of yarn (count wise) waiting to be wound on soft packages. i. Stock of soft wound packages (count wise) waiting for delivery to dyeing. j. Special instructions if any. Management information system related Check whether the following information are entered in the system properly: a. The count and quantity of yarn received for soft winding from yarn godown. b. The date and time of receipt of yarn from godown. c. The number of soft wound cheeses prepared count wise and sent to dyeing. d. The stock of raw yarn count wise. e. The stock of soft wound packages count wise. f. Winding machine wise production. g. Winder wise productions. h. Materials returned back to godown. General a. Whether the humidity is maintained as per requirement? b. Whether the remnant cones are counted, weighed and returned to yarn godown with proper documentation? c. Whether the machine cleaning was done properly by the maintenance people? d. Whether the shop floor was handed over to you in a clean condition? e. How was the condition of your department when you handed over the works to next shift?

32

Handbook on Fabric Manufacture

3.5.3

Control points in dyed yarn winding

a. The count and type of yarns, number of cones to be prepared in each shade for the design in hand and the deadline for giving wound material. b. The length and weight of each cone to be maintained. c. Type of cone to be used (plastic cones or paper cones). d. The identification marks to be put on dyed yarn cones. e. Engagement of skilled employees. f. Deciding of work norms and allocation of workmen. g. Designing maintenance activities and implementing them. h. Deciding on the information to be written in the log book and data to be furnished for MIS.

3.5.4

Check points in dyed yarn winding

Material related a. Whether the yarn received are as per the design requirements? b. Whether required quantity of yarn is received in each shade as per the design requirement? c. Whether the dyed yarn cheeses are good in shape and have uniform moisture? d. Whether all the yarn given in a lot belongs to same shade and lot? e. Whether the quality of wax discs is as per requirement? Winding machine related a. Whether the drums are in good condition? b. Whether the stop motions are working properly? c. Whether the length counters are working normal? d. Whether the waxing units are working properly? e. Whether the tensioners are in good condition? f. Whether the tension discs are coded suitably depending on their weights? g. Whether the quality of paper cones and their fitting in the cone is proper? Setting related a. Whether the tension discs on all drums are uniform for the count and shade being worked? b. Whether the speed set is as per norms? c. Whether the speed set on all drums are uniform and as planned?



Winding–yarn dyeing section

33

d. Whether the length set on all drums are uniform? e. Whether the length set gives the required weight as per the count of the yarn? Performance related a. Whether the breakages are within limits? b. Design wise productions completed and cones required in each shade to complete packing. c. Whether the waxing is being done properly? d. Whether the cones are uniformly dried and conditioned before taking for winding? e. Whether the humidity is maintained as per requirement? f. Production efficiency. a. Winding machine wise performance. b. Winding drum-wise performance. c. Winder-wise production and wastes generated. Work practice related a. Whether the stop motions are kept functioning properly? b. Whether winders are putting correct type of knots? c. Whether the workers are following the material coding systems as per requirements? d. Whether the machines and surroundings are kept clean? e. Whether all winders are putting hard wastes in the designated place or not? Documentation and records a. Productions recorded against design and against each winder. b. Winding drum wise productions. c. Whether the dyed yarn cones are weighed and packed before sending to yarn godown with proper memo and documentation? d. Whether production data are entered in system in time or not? e. Whether the remnant dye packages are counted, weighed and returned to yarn godown with proper documentation? Waste monitoring a. What is the quantity of hard wastes generated? b. Whether the hard wastes generated are within the norms?

34

Handbook on Fabric Manufacture

c. Whether the wastes are monitored machine wise and shade wise or not? d. Whether the wastes are weighed, labelled and recorded before sending it to waste section? Log book related Check the entry of the following in the log book: a. Machines worked. b. Counts and shades worked on each machine. c. Drums allocated for different counts and shades. d. Men employed on different counts and machines. e. Production achieved count wise, winder wise, design wise, Shade wise and machine wise. f. Stock of dyed yarn waiting for winding. g. Stock of wound yarn to be packed and sent to yarn godown. h. Stock of paper cones. i. Stock of wax discs. j. Hard wastes produced design wise and shade wise. k. Stoppages of machinery with reasons. Management information system related Check whether the following data are entered in the system correctly for MIS. a. Design numbers. b. Count-wise, design-wise and shade-wise number of dye packages received from dyeing for winding. c. Machine allotted for different designs. d. Gram and length set for cones. e. Production design wise, count wise, shade wise, machine wise, winder wise. f. Material despatched to yarn godown – design wise, count wise, shade wise number of cones and kilograms. General a. Whether the machine cleaning was done properly by the maintenance people? b. Whether the department was handed over to you in a clean condition? c. How was the condition of your department when you handed over the works to next shift?



Winding–yarn dyeing section

3.6

Normal problems

3.6.1

Problems in soft winding

35

Too soft yarn package, too hard yarn package, side stitches, ribbon formation and count mix up are normal problems in soft winding. Too soft yarn package A lower tension on the yarn being wound is the reason for soft packages, which can be due to a lower tension weight applied, yarn passing out of tension guide, and very low speed of winding. The soft packages touch the adjacent package in the dyeing vessel and hinder the movement of dye liquor and results in uneven dyeing. Too hard yarn package Too hard yarn package is normally due to excessive tension applied on the yarn, a higher speed of winding and a higher relative humidity in the work area. Hard packages does not allow the dye liquor to pass easily and hence inner portions do not get dyed properly. Side stitches Improper traverse of the yarn, vibrations in winding head, and a loose adopter are the normal reasons for getting stitches in the yarn package. The side stiches give problem in unwinding and hence results in higher yarn wastes. Ribbon formation Malfunctioning of ribbon breaker and improper cleaning of drums are the reasons for ribbon formation. The ribbons do not allow free movement of dye liquors and results in uneven dyeing. Count mix-up Improper colour codification and lack of education to the workmen and staff are the main reasons for mix up of cones or cheeses. A count mix up produces a defective fabric, and hence complete fabric shall have to be rejected.

3.6.2

Problems in dyed yarn winding (hard winding)

Variations in yarn length on cones, hard wound cones, too many breaks while winding and stitches are some of the normal problems in dyed yarn winding. Variations in yarn length on cones In spite of adapting length measuring systems in cone winding, we get variations in length wound between cones. This results in higher remnants while

36

Handbook on Fabric Manufacture

running out the yarns on warping or knitting creel leading to higher wastes, and more losses. The following are some of the reasons for length variation. 1. Uneven tension is one of the main reasons for length variations. This may be because of improper unwinding due to yarn sticking to inner layers, variations in tension discs, and wax not rotating properly. 2. Slippage of yarn while winding due to jumping cone holders or wax holding the yarn. 3. Irregular pattern of breakages between drums. 4. Improper shade cutting. Hard wound cones Inadequate drying of dyed yarns and higher tension applied on yarn are the normal reasons for hard wound cones. Hard wound cones do not unwind easily in warping or knitting and becomes tighter whereas other yarns shall be with a different tension in the warp sheet or in knitting. This results in barre effect in circular knitting and higher breaks in warping. Too many breaks while winding Yarn tendering while dyeing is the main reason for too many breaks while winding. This problem can be seen more in extra dark shades and when yarns are reprocessed to get correct shade. The other reasons for higher breakages are: 1. Yarn coils getting disturbed while dyeing, washing and handling of yarn packages in soft winding as well as after dyeing. 2. Over drying of yarn after dyeing. 3. Higher tension or speed applied while rewinding. Stitches The reasons for stitches are improper fitting of paper cones on the cone holder, removing the running cone in between and refitting on the cone holder and vibrating cone holder. The stitches increase breaks while unwinding in warping, knitting or in loom.

3.7

Dos and Don’ts

Understand clearly what you are supposed to do without fail and what you should not do at any cost. Some examples are given below.

3.7.1 Dos 1. Verify and understand the design in detail before starting your work. Workout the number of cones in each shade/count, the weight per



Winding–yarn dyeing section

2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

37

cone required and the assortment in which the materials are to be delivered. Verify the calculations and assumptions before implementing. Stick to colour codes and other identification system agreed between sections. Work for getting maximum utilisation and efficiency for which men are engaged. Have control on generation of hard wastes. Check the grey yarn lot running. Check the visual quality of grey cones running. Check the cleanliness of the machine. Check the tension and uniformity in tension. Check the working of waxing in case of wax being used. Check the dimensions of the cheeses using a calliper (Figure 3.7).

Figure 3.7 Measuring diameter of cheese

12. Decide on the length to be set after considering allowances for wastes and slippage. 13. Check the length set and compare with the standard. 14. Check the speed set. 15. Check the production to be taken out in the lot. 16. Verify the dyed yarn lot number, shade number and compare with the design card and production plan. 17. Confirm that the yarn is approved by Q.A (Quality Assurance) before it is brought to winding. 18. Check the available quantity of yarn in winding and the yarn required for completing the lot before bringing fresh yarn. 19. Check the details written in display boards.

38

Handbook on Fabric Manufacture

20. Enter the lot details on the lot identification card and hook it on to the trolley carrying soft wound packages. 21. Load the soft packages in pegged trolley only. 22. Take the stock of yarn at the end of each shift and hand it over to next shift supervisor. 23. Discuss with the dyeing in-charge before taking any yarn for soft winding. 24. Put specified thread band on the empty perforated plastic tube for identification of count where count wise colour codification is not in practice. 25. Make trail on five drums before finalising parameters on all drums. 26. Keep only those materials that are required for working in the shift. 27. Always insist on wearing waist bag and collecting all hard wastes in the bag. 28. Hand over the machines and the winding section to next shift in a clean condition.

3.7.2 Don’ts 1. Do not decide on colour code by yourself. 2. Do not draw or produce more than the ordered quantity. 3. Do not increase speeds of the machine or the weight of packages to get more productions. 4. Do not engage people in the shift unless you have confirmed orders. 5. Do not press the soft wound cheeses. 6. Do not start the machine if the grey yarn received is not as per the plan given. 7. Do not run the drum if the cone quality is not as per requirement. 8. Do not use broken tubes or springs (Seat on tubes) for winding yarn. 9. Do not work the drum which is not giving the required package density. 10. Do not start winding if the design number, shade number and lot numbers are not matching to design card. 11. Do not accept the yarn if colour code band is missing or not as per requirement. 12. Do not take the yarn for winding if you find the yarn to be harsh. 13. Do not bring the yarn from godown without giving the required issue slip duly signed.



Winding–yarn dyeing section

39

14. Do not allow to clean the machine with compressed air while working. 15. Do not allow anyone to use compressed air for cleaning self. 16. Do not run bleached yarn by the side of dark shades. 17. Do not allow using of loose hard wastes for cleaning the machines. 18. Do not allow wearing of loose cloths while working on the machines.

3.8

Responsibilities of supervisor in winding

1. Completing the assigned jobs and achieving the production with quality as agreed upon besides maintaining the discipline, housekeeping and team working. 2. Ensuring that all the programmed machines are kept working. 3. Getting the machines started in time and achieving maximum utilisation. 4. Verifying and ensuring that the lengths set on each drum are as per the requirement of yarn running on that drum. 5. Responsible for getting the tensions set properly. 6. Ensuring that wax discs are rotating properly where waxing is being done. 7. Responsible for ensuring clean working area all the time and all materials and records are kept in their respective place. 8. Verifying the yarn lot number and shades before taking yarns for winding. 9. Checking and adhering to the colour codes as decided. 10. Taking corrective actions like getting the settings corrected, getting the cones rewound, while limiting him to the authorities given to him. 11. Getting the hard wastes collected put in designated places and disposed after documenting. 12. Ensuring safe handling of the cones and preventing hard wastes due to poor handling practices. 13. Supplying cones and cheeses in time to user department. 14. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline. 15. To report HRD in case of any accidents and filling the accident reports in time.

40

Handbook on Fabric Manufacture

16. To help winding in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.

3.9

Authorities of winding supervisor

1. Questioning the jobber and workers when the work done is not satisfactory. 2. Sending memo to HRD in case of serious lapse in discipline by any of the employee working under him. 3. Allotting or changing jobs to winders and other workers considering their skills. 4. Arranging rewinding of the cones in case of winding defects and informing higher authorities regarding the quantity and the reasons for rewinding. 5. Recommending leave and/or permission to the subordinates in the section. 6. Stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions.

3.10 a. b. c. d.

3.11

Some hints for better performance Always keep the winding area clean. Do not bring more yarn for winding and keep in stock. Observe for repeated breaks in drums and attend the problems. Keep the idle drums at lowest possible level.

Applicable formulae

Pr oduction per Winding speed in Y.P.M × No of minutes in shift × Efficiency % = drum in kg Count Ne × 840 × 2.2 × 100

The volume of cheese is worked by using the formula

π × l (D2 − d 2 ) 4 π = 22/7, l = length of the cheese, D = full cheese diameter and d = bare cheese diameter. When the measuring units are in cm. we get the result in cubic centimetre. Divide the figure by 1000 to get the volume in litres (Figure 3.8).



41

Winding–yarn dyeing section Full cheese dia = D

Cheese length = l cm.

Bare cheese dia = d cm. Figure 3.8 Measuring dimension of cheeses

3.11.1

Working out production and work loads

Following table gives the method of working out production required and the workloads that can be given with examples. Sr. No

Activity

Time/ operation in sec

Soft winding

1 to 1 rewinding

Final winding for warp

A

To take charge from previous technicians in minutes

300

5

5

5

B

To receive instruction from shift in charge in minutes

300

5

5

5

Ca

Resultant count worked – Ne

 

20

20

20

Cb

No of drums allotted

 

55

55

27

Cc

Speed MPM

 

750

700

600

Cd

Final package weight g

 

1100

1100

350

Ce

Supply package weight in g

 

1100

1100

1100

Cf

Length of yarn per supply cone = Ca × 840 × Ce)/ (453.4 × 1.08)

 

37,740

37,740

37,740

42 Sr. No

Handbook on Fabric Manufacture

Activity

Time/ operation in sec

Soft winding

1 to 1 rewinding

Final winding for warp

Cg

Number of supply cones per one final cone = Cd/Ce

 

1.00

1.00

0.32

C

Time to run one supply cone in minutes = Cf/Cc

 

50.32

53.91

62.90

D

Placing the cones at bottom and piecing in minutes

13.01

0.2168

0.2168

0.2168

Ea

Breaks per cone

 

0.15

0.3

0.15

Eb

Time to mend one break in minutes

28

0.4667

0.4667

0.4667

E

Time to mend break per cone (Ea * Eb)

 

0.0700

0.1400

0.0700

F

Time for building one cone = Cg × (C + D + E)

 

50.6062

54.2705

20.1047

G

Writing count on cones by chalk

5

0.0800

0.0833

0.0833

H

Time for writing yarn details on sticker

4.8

0.0800

0.0800

0.0800

I

Time for putting stickers on machine

4

0.0667

0.0667

0.0667

J

Time for putting stickers on cone

0.67

0.0112

0.0112

0.0112

K

Time to fix empty cone on drum

1.75

0.0292

0.0292

0.0292

L

Time for wrapping yarn end to the empty cone

11.35

0.1892

0.1892

0.1892

M

Time to remove cone in minutes

5.05

0.0842

0.0842

0.0842

N

Time for putting a cone in basket in minutes

3.93

0.0655

0.0655

0.0655

O

Total operating time per one cone building in minutes = Cg × (C + D + E) + (F + G + H + I + J + K + L + M + N)

 

51.21

54.88

20.71



Sr. No

43

Winding–yarn dyeing section

Activity

Time/ operation in sec

Soft winding

1 to 1 rewinding

Final winding for warp

P

Number of working minutes in a shift

 

720

720

720

Q

No of cones per drum at 100% machine working (Number of doffs) = (P/O)

 

14.0592

13.1196

34.7594

Ra

Expected production per drum in g

 

15465.11

14431.58

12165.79

R

Work load per cone = Cg × (D + E + G + H + I + J + K + L + M + N)

 

0.8927

0.9660

0.2851

S

Variable work load per drum = (R × Q)

 

12.5502

12.6736

9.9096

T

Number of minutes at 75% workload per shift

 

11

11

11

U

Fixed work load

 

10

10

10

V

Drums that could be allotted per winder = (T − U)/Q

 

0.04

0.04

0.05

W

Suggested drums per winder

 

40

55

55

X

100% production per drum in g = (Cc × 480 × 453.4)/ (1.08 × 840 × Ca)

 

15739.46

14690.16

12591.57

Y

Efficiency at full working = (Ra × 100/X)

 

98.26

98.24

96.62

Z

Expected efficiency after deducting time for taking charge, instructions and for patrolling at 120 min)

 

81.88

81.87

80.52

4 Quest for ideal yarn dye package

4.1

Winding of soft package for dyeing

Winding yarn on to dye package is the first step in yarn package dyeing process and success of dyeing depends on the quality of winding. Hence, it is necessary to understand the objectives and the technical requirements of the process, be familiar with the working principles of package winding machine and required technical parameters, and understand the theoretical back ground and build-up of winding package. Note: The term “Yarn dyeing” in this chapter also includes yarn bleaching, scouring, washing, etc., which are all done in wet stage. The soft package winding is the most important pre dyeing operation, which directly affects not only the dyeing quality but also post dyeing operations such as the performance in post winding like poor unwinding, yarn breakages, wastage, rejections, etc. “Well wound is half dyed”, is the popular saying. One can’t expect miracles by installing the most advanced dyeing machinery if the packages are of poor quality. In order to ensure uniformity and consistently good winding, precise adjustment and careful maintenance of the equipment is necessary and the operators must be trained and closely supervised. Factors like count of the yarn, angle of winding, tension during winding, diameter of the package, the winding ratio, compactness and size of the feed package affect the package make up. Hence they must be considered while selecting a machine for soft package winding. Hard and soft places can occur within a single package if winding is poor, causing some part of package to dye lighter or darker. The most compact part of any package is edges or shoulders, where the yarn turns the corner and is the most difficult place to wet out and penetrate during package dyeing, resulting in lighter dyed or not at all dyed undyed spots. “Cupping” or “Crimping” is the only solution found out by the dyer to overcome from this problem. Cupping is the method of softening the hard edges of packages by pressing manually by hand; thus, hard edge breaks and become softer.

4.1.1

Crossing or winding angle

It is the angle at which the yarns cross each other on a wound package; smaller the crossing angle denser will be the package.



4.1.2

Quest for ideal yarn dye package

45

Winding ratio

It is number of turns of yarn per revolution of the package, or distance between the threads of layer. More the number of turns per revolutions more is the density. Increasing the distance between the threads of a layer decreases the density.

4.1.3

Package stability

It is the tendency of wound yarn on the package holder to remain stable. If the yarn layers do not hold well on the package holder, (tube) the dye package may deform easily in subsequent processing. For example, on precision winding machines the winding angle reduces with increase in package diameter, thus, making the packages a little bit harder from outside layers, which may fall off during handling.

4.2

The package

The yarn to be dyed is first wound in to a package. The weight and diameter of the package is limited by the space available between the spindles of the dye carrier. The package dimensions and weight are influenced by the type and construction of the yarn to be processed, machine flow rate, and package holder, i.e. spring cheese or plastic cheese (Figure 4.1).

Full cheese dia = D cm.

Cheese length = l cm.

Bare cheese dia = d cm

Figure 4.1 Soft wound package

Author: Please check the citaions of Figures 4.1–4.4 and correct if necessary.

46

Handbook on Fabric Manufacture

The yarn package must be stable enough to withstand the handling during loading, processing and unloading from the machine. It should withstand the temperature change and flow volume and flow direction of liquor. It should accommodate a small amount of shrinkage and swelling during processing with temperature increase as well as wetting.

4.2.1

Package holder (yarn holding tube)

Package holder may be an SS (stainless steel) dye spring, a perforated plastic cheese (which is reusable or disposable) or perforated plastic cones. Each one has advantages and disadvantages. A dyeing package is characterised by its geometry and its density profile. The bigger diameter dye centre has advantages over the smaller inner diameter packages as it offers lesser resistance to the flow liquor in case of in to out and at the same time area exposed to dye liquor is more for better uniformity of the dyeing. As a thumb rule, the main objective from the dyers point of view is to get the material uniformly dyed throughout the package, the machine is used to its full capacity, the hydro extraction and drying is done without affecting the quality of the dyed material and un winding is trouble free.

4.2.2

SS dye springs

The SS dye springs are most commonly used package holders. The main advantages are that these are reusable, compressible, making a perfect column after pressing, and spacers are not used between the packages; Thus reducing the possibility of channeling. Dye springs offer much lesser resistance to the liquor flow through the packages. Due to the higher compression possibility the dyeing machines can be loaded to a higher capacity and liquor ratio can be reduced for better economy of the process. The main disadvantage is the higher initial investment. In some cases due to the shrinkage of the yarn, channeling takes place causing unevenness. Another disadvantage is poor unwinding property, particularly inner most layers are not easily unwind resulting in yarn breakages and wastage of yarn. In turn, this also affects the yarn quality by the addition of more number of knots (joints) at initial layer of yarn. Now a day SS springs are rarely used for cotton yarns.

4.2.3

Perforated cones

Conical dye packages are conventionally being used for their comparatively good run off behavior. The material wound on the cones of the



Quest for ideal yarn dye package

47

standard weight and dimensions are taken for dyeing. Generally spacers (washers) are used between individual cones to make the dyeing column. The biggest advantage of cones is considered to be their subsequent use in next operation without rewinding. However, these are no more popular due to their numerous disadvantages. Use of spacers (washers) is itself a big problem, as it causes the liquor blow out at the joints. The liquor flow through the cone is also not uniform due to the different dimensions at the bottom and tip of the cone. The dye centre is defined by the cone tip inner diameter, which pose resistance to the liquor flow resulting in unleveled dyeing. More space remains unutilised due to the shape of the cone which reduces capacity utilisation and higher material liquor ratio. The solid cones cannot be compressed; hence the machine remains under loaded. The shade variation between inner layers and other portions cannot be cut and removed as there is no rewinding, which can result in poor appearance of the fabric.

4.2.4

Perforated plastic and SS dye tubes

These tubes, an alternative to the dye springs, are made of polypropylene (either for multiple or single use) or stainless steel. Winding is uniform on perforated dye tubes due to its special design. The flow through the package is improved with better designed and bigger perforations or holes. The perforated plastic tubes are available in various colours that help in identifying the yarn count; thus avoiding the chances of mix-up of yarn. Different qualities can be processed simultaneously without fear of mix-up. It has consistent dimensions, and remains intact when used and handled properly. Perfectly designed adaptor end eliminates the use of washers while loading in to the dye spindles, and perfect fitting minimise the chances of liquor blow out at the joints. The density of the dyeing column is governed by the individual packages and hence it can be controlled at winding stage itself. The thread reserve remains intact because these are not compressed. These are suitable particularly in case of materials which are delicate in nature and having higher wet shrinkage properties. The main disadvantage of perforated solid tubes is non-compressibility, which reduces the loading and hence machine capacity. The yarn generally sloughs off in case of the yarns which get relaxed after heat treatment. Tube edges are easily damaged if not taken care while loading packages in to dye spindles. The tubes get deshaped (oval) if the hydro extraction facility is not proper (speed and centrifugal force of pressure during hydro extraction). If winding quality and package density are not proper or uniform within and between packages, the dyeing results would be poor.

48

4.2.5

Handbook on Fabric Manufacture

Package weight and density

The package weight and density are two important parameters needing standardisation for uniform and trouble-free dyeing. The package, both soft and hard, should conform to the standards. When too soft, liquor flowing through it will have least resistance and cause channeling, leaving some parts of the package relatively undyed or lighter. With hard wound packages, a point can be reached where the flow of liquor is restricted to such an extent that poor dyeing or un-dyeing may occur. The package weight and dimensions depend upon the type of the machine, its flow rate, automation, type and construction of the yarn, type and quality of package holders (empty tubes). The typical density norm for different type of yarns is between 350 and 400 GPL (grams per litre). The most important requirement of soft-package for dyeing are, 1. Density of the package should be uniform throughout the package, i.e. layer to layer density is controlled. 2. The packages should not have hard edges or these must be broken or cupped by a suitable device or manually. 3. The package weight must be controlled so that all the packages fall within the standard norms. 4. The density variation from one package to another must be controlled statistically and CV% should not exceed 5%. Following factors affect the flow of liquor through the packages: 1. Yarn or filament fineness – The permeability increases with increase in yarn diameter. 2. Yarn twist – The permeability decreases with the increase in yarn twist. Two twisted yarns can adopt a flat rather than circular shape, which makes the packages more permeable. 3. Winding ratio – More the number of revolutions of package makes the package less permeable. 4. Winding angle – The smaller winding angle makes the packages less permeable. 5. Yarn tension at winding – The higher yarn tension at winding makes the package harder and denser and hence less permeable. 6. Swelling and shrinkage – The higher swelling and shrinkage during dyeing make the package less permeable.

4.3

Conventional or random winding machines

In conventional winding machines grooved drum acts as both the driving as well as the traversing element. The winding is done through indirect drive to



Quest for ideal yarn dye package

49

the package, which is called as the friction drive. The yarn lay formed is random; hence it is called random winding. The main characteristics of random winding are, 1. Winding angle: Since grooved drums are used for winding, the winding angle remains same. 2. Winding ratio: The number of coils per rotation of the package decreases as the diameter of the package increases, so the package is softer at outer layers. 3. Ribbon formation: Ribbon formation may occur at certain points within the package when package reaches to a certain ratio of drum diameter. 4. The package stability is good. 5. Layer to layer density is not very uniform throughout the package. 6. Hard edges formation may occur at the yarn turning at the package ends. 7. Machine cannot be run with very high speed, because it is very difficult to maintain good density at higher speeds on random winding machines. 8. Machine cost is low.

4.3.1

Patterning or ribbon formation and hard edges

Patterning or ribbon formation is seen when yarn being wound rests exactly on the earlier wound layer of yarn. Ribbon breaking or anti-patterning devices are attached to grooved drum winding machines. When the ratio of traverse frequency to the rate of revolution of the package becomes full numbers like 1:1, 1:2, 1:3, etc., the turns of new layer are deposited exactly on the top of the turns of the preceding layer, and this process repeats itself for several successive layers till the ratio changes. This generates informally crossing ridges, the so called pattern winding or ribbon formation zones. This restricts the dye liquor penetration in to the package and makes un-level dyeing. This also affects the unwinding and may result in yarn breakage too. The machine must be equipped with good and effective anti-patterning device, which minimise the pattern/ribbon formation. The pattern breaking device ensures that the traverse speed is not uniform but is subjected to variation thus it will not allow the ratio of traverse frequency to the rate of revolution of package to become 1:1, 1:2, 1:3, etc., and eliminates the pattern formation.

50

4.3.2

Handbook on Fabric Manufacture

Hard edge formation

Due to the nature of friction winding with the grooved drum, the yarn stays for a relatively longer time at the edges, and creates hard edge. The machine must be equipped with a proper arrangement in which the cradle or the cheese holder slides slightly (by few mm) on the drum through a lateral movement device reducing the chance of hard edges formation by widening the edge area.

4.3.3

Traverse of the package

While winding particularly on solid perforated cheeses, we should take care that the perforations on both the sides are covered completely and equally, if these are not covered equally there may be undyed parts. If yarn is wound on blind area, channeling may take place when there is no winding on a particular end making tube visible or not covered by yarn.

4.3.4

Weight release mechanism

Since the weight of the package increases with the increase in diameter of the package, it increases the cradle pressure on the drum and affects the density of the packages. Therefore the machine must be equipped with a proper weight release mechanism to balance out the increased package weight. New machines are equipped with a programmed cradle weight regulation system.

4.3.5

Length measuring device

The machine must be equipped with a length measuring unit control system to control the package weight variation, that helps to control and maintain right quantity of yarn per package.

4.3.6

Balloon breaker

The balloon breaking device in winding machine provides more flexibility to use different size of feed packages and also reduce the breakage rate.

4.3.7

Yarn tension controlling

It is very important to have a good yarn tension control system that ensures the uniform package density within the package and between packages. Since tension varies within feed package (at start and at remnant stage), it is very difficult to control manually. Hence positive tension control system is necessary to get uniform package density.



4.3.8

Quest for ideal yarn dye package

51

Winding speed

The winding speed is also a constraint in random winders, but now machines are available with individual drum drives which can run at different speeds and it is also possible to make soft packages on automatic winders which can run up to 1400 m/min.

4.4

Ideal dye package

Packages wound on precision winders with closed-loop tension control systems can fully meet all yarn dyeing and post dyeing requirements in terms of quality and economy. In yarn dyeing even the most advanced dyeing equipment will not produce perfect results without properly wound dye packages. In fact, with the right kind of package the job of yarn dyeing is half done. So a properly wound yarn dye package takes away 50% of dyers worries.

4.4.1

Requirements for a good dye package

A yarn dye package has to meet two major aspects, i.e. A. Demands from dyeing. B. Demands from downstream processes and quality control.

4.4.2

Dyeing related requirements

These include the basic physical issues relating to the fundamental requirement of each and every fibre in the dye package, which is to be exposed to an equal amount of dye liquor over an equal length of time, and thus we require, a. Uniform liquor flow within a package. b. Uniform liquor flow between packages (within batch) c. Uniform liquor flow between packages (batch-to –batch) In other words, each and every yarn dye package has to conform to a prescribed density, and this density has to be uniform from inside to outside and from top to bottom of the package. Similarly, packages of identical density and dimensions have to be produced on any drum of the winding machine at any given time, means total reproducibility. The density of spun yarn dye packages recommended by leading dyeing vessel manufacturers is, For cotton – 400–420 GPL For cotton/polyester – 430–450 GPL

52

Handbook on Fabric Manufacture

However, a softer package gives still better uniformity in dyeing and hence in India it is common to have package density of 360–380 GPL for cotton and 380–400 GPL for cotton polyester blends. Since such packages, as compared with those intended for use in warping creels or knitting creels, feel softer, also referred as “soft packages”.

4.4.3 Requirements from downstream processing and quality control Apart from yarn dyeing these packages must also conform to certain post dyeing requirements, like a. Optimum unwinding properties, b. Resistance of package to handling. c. After dyeing, the yarn will be used in either weaving or knitting, and thus has to be unwound for further processing. Therefore, no tension variation or disturbed yarn layers must be present, as these defects are a major source of hairiness and yarn breakages.

4.5

Principles of winding

Mainly there are two types of windings, random winding and precision winding.

4.5.1

Random winding

The random wound package is characterised by its constant winding angle and the resulting decrease in the number of coiling per rotation of the package with increasing diameter. As a result of the friction drive and the method of yarn displacement by a grooved drum, the yarn lay is at random, hence, the term “random winding” (Figure 4.2).

Inial Coiling Package outer coiling Figure 4.2 Initial and outer coiling in random

Main issues of random winding are, a. Constant winding angle. b. Variable winding ratio.(reduced number of coiling per rotation as package diameter increases)



Quest for ideal yarn dye package

53

c. Pattern forming (ribbon formation) d. Cheap machine to make.(low cost machine) e. Good package stability. f. Poor liquor flow properties g. Poor unwinding properties. The presence of pattern is an inherent problem of random winders, as they use grooved drum as both driving and traversing element. Thus, whenever the diameter of the grooved drum and that of the package being wound reach certain ratios, ribbon forming occurs. This can be controlled via anti-patterning devices, but not eliminated.

4.5.2

Precision winding

Precision wound packages are characterised by their constant number of coiling per rotation of the package. The winding angle decreases as the package diameter increases. In true precision winding, the package is driven through the spindle and the yarn is displaced by a separate system, such as propeller blades or thread guides (Figure 4.3).

Initial coiling Package outer coiling

Figure 4.3 Inner and outer coils in precision winding

There is no slippage in the drive or uncontrolled displacement of yarn, hence the term “precision winding”. Main issues of precision winding are, a. Constant winding ratio.(permanent number of coiling per rotation as diameter increases) b. Variable winding angle (decreases as package diameter increases) c. Moderate cost of machine. d. Acceptable package stability. e. Good liquor flow properties f. Excellent unwinding properties. Precision winding machines use separate elements to drive the yarn package and to displace the yarn. Digital tension control systems, helps to

54

Handbook on Fabric Manufacture

produce packages of absolutely uniform density from inside to outside and from top to bottom, whereas random winders produce a predictable and inherent variation in density from inside to outside.

4.5.3 Step-precision winding: (DIGI winding or hybrid winding) Here, in addition to the features of precision winding, the traverse ratio is variable, allowing for any winding angle (and thus, for any number of coiling per rotation) at any diameter of the package (Figure 4.4). Inial coiling Package outer coiling

Figure 4.4 Initial and outer coils in Step-precision winding

Main issues of step-precision winding are, a. Controlled winding angle. b. Controlled winding ratio. c. High cost machine d. Good package stability e. Good liquor flow properties. f. Good unwinding properties. This type of machine combines the advantages of random winding and precision winding without any of disadvantages. However, such machines cost more and until recently were the only solution for achieving packages of uniform density.

4.5.4 Resulting packages – packages that conform to requirements As we can see from the above, only precision-wound packages (wound on machines with digital tension control systems) and step-precision wound packages, meet all requirements of a dye package, as they are only types that can offer good liquor flow characteristics, uniform density and excellent unwinding properties. Precision packages can be wound to the recommended dyeing density directly on the soft package winder. Thus the practice of compressing, leading



Quest for ideal yarn dye package

55

to displaced yarn layers, tension variations during unwinding and increased hairiness can be eliminated. Moreover, only precision winding machines offer full control over yarn speed and traverse motion. On random winders, which use friction drive, there is no positive control over package rotation and thus yarn speed. To satisfy the requirement of within batch and between batch uniformity, single drum control is required, which practically conventional random winder do not offer.

4.5.5

Packages that do not conform to requirements

As explained above, a random wound package cannot offer uniform density and thus cannot offer uniform liquor flow characteristics. It is thus unsuitable for use as a soft dye package. To address this inherent inadequacy, some dyers resort to compressing random-wound packages. The idea is that by subjecting the package to pressure, the softer areas will compress while the harder areas will not. In practice, this means that a random-wound package intended for dyeing is wound to a low average density of 320–350 GPL and then compressed by 20–25% to reach a final density of approximately 400 GPL. Dye houses resorting to this practice do so in the belief that they have found a way around the somewhat costlier precision or step-precision wound packages. However, they do so disregarding the significant downstream and quality issues caused by compressing. By compressing a random-wound package of 6 inch traverse by 20–25% will mean that the package will be dyed at a traverse of around 4.8–4.5 inches. After dyeing and release of the compressing force, it will not relax to its previous shape and size again. This is a clear warning signal that by compressing, the yarn layers have been disturbed and when unwound such a package will cause higher tension variation and higher levels of hairiness. From a quality point of view, compressing soft packages for yarn dyeing is an out dated practice and given the growing focus on yarn hairiness, is most likely to come under increasing awareness of garment quality. Precision-wound and step-precision wound soft packages offer excellent unwinding properties and thus can be directly used on knitting machines or warping creels after dyeing. Packages wound on precision winders with closed-loop tension control systems and on step-precision winders can fully meet yarn dyeing and post dyeing requirements in terms of quality and economy. Considering the quality of dye package and economy, precision soft package winders equipped with digital tension control systems are viable than equivalent step-precision winders.

56

Handbook on Fabric Manufacture

4.6

Main features of dye package machines

The table below gives the comparison of the three types of winding machines. Comparative characteristics Characters

Random winding

Precision winding

Step precision winding

Technology

Old

Present

Advanced

Technology problem

More

Moderate

Almost eliminated

Machine speed

Low to moderate

High

High

Machine cost

Low

Moderate

High

Machine productivity

Low

High

High

Winding angle

Constant throughout the package

Variable. Since propeller blades or guide is used for yarn displacement the winding angle does not remains the same and decreases with the increase in package diameter

Remains almost constant throughout the package and controlled

Winding ratio

Variable

Constant

Constant and controlled

Package stability

Stable

Moderate

Good

Density

Change from package inner layer to outer layer (harder to softer) Inherent variation

Does not change with diameter of package

Does not change with diameter of package

Ribbon formation

Ribbon formation occurs at certain ratio

No ribbon formation

No ribbon formation

No-of coils per turns of package

Decrease in no-of coils per rotation as package diameter increases

Remains same as the diameter of package increases because the number of displacement remains constant per rotation of the package

Remains same as the diameter of package increases because the noof displacement remains constant per rotation of the package



Quest for ideal yarn dye package

57

Characters

Random winding

Precision winding

Step precision winding

Yarn displacement (traverse)

Through grooved drums

With the help of guide or propeller blades

With the help of guide or propeller blades

Yarn lay on package

Random

With the help of guide or propeller blades

With the help of guide or propeller blades

Yarn tension control

Manually with washers

Through electronic or digital yarn tension control system, which vary as the diameter of package increases

Through electronic or digital yarn tension control system, which vary as the diameter of package increases

Hard end formation at Package edge

Yes, hard edges at turning points

No hard edges

No hard edges

Package drive

Indirect drive or friction drive

Each package is driven through individual motor

Each package is driven through individual motor.

Dye package loading in to a dye spindle

Moderate (ensure proper fitting of each package)

Good, fitting properly

Good, fitting properly

Liquor flow

Restricts at hard edge, ribbon formation place

Good, un interrupted liquor flow

Good, un interrupted liquor flow

Unwinding.

Some yarn breaks due to variation in unwinding yarn tension, and at the hard edges of package

Good, smooth and break free unwinding

Good, smooth and break free unwinding

Technology and from the dyers and post dyeing point of view the precision winding machines with a digital tension control device and solid perforated plastic cheese is the best combination to achieve standard package quality and production.

4.7

How to calculate the package density?

The package density is expressed as weight per unit volume say as grams/ litre (GPL) or gm/cc. It is easy to know the net weight of yarn on a package.

58

Handbook on Fabric Manufacture

Calculation of volume occupied by yarn on package is normally measured on dimensions of empty as well as wound packages. (A) Cylindrical package Let the gross weight of package is = W1 g. The weight of the empty cheese is = W2 g. Hence, net weight of yarn is W3 = W1 − W2 Height of cheese (traverse) is = h mm Outer radius of empty cheese = r1 mm Outer radius of wound cheese = r2 mm Volume of empty cheese V1 = πr12h Volume of wound package V2 = πr22h Volume of net yarn wound V3 = V2 – V1 Density ( GPL ) =

W3 ( Net weight of yarn in g ) V3 Net yarn volume

× 1000 × 1000

(B) Conical package: Let the gross weight of package is = W1 g The weight of the empty cone is = W2 g Hence, net weight of yarn is W3 = W1 – W2 Height of cone (taper height) = h mm Radius of cone base (OD) = R mm Radius of cone top (OD) = r mm Calculation of volume of empty cone and yarn wound cone: 1 Volume = π h R2 + Rr + r2 3

(

)

Empty cone volume and full cone volume calculated separately. To get actual yarn volume, subtract empty cone volume form fully wound cone volume. Volume of empty cone V1 = πr12h Volume of wound cone V2 = πr22h Volume of net yarn wound V3 = V2 − V1 Density ( GPL ) =

W3 ( Net weight of yarn in gm ) V3 Net yarn volume

× 1000 × 1000

5 HTHP yarn dyeing

5.1 Introduction High temperature high pressure dyeing machines are designed for processing wound yarn packages at a higher speed. The processing includes all wet processes like scouring, bleaching, dyeing, finishing and partial drying. The yarn to be processed is first wound onto a perforated tube at low tension, termed as soft package. The soft packages are loaded on the spindles of the carrier of the dyeing machine. Soft packages loaded on spindles are locked at the top. The carrier has a loop in the centre that can be hooked to the overhead bridge crane. The Carrier is inserted in the main dyeing vessel. The top lid is closed and locked.

Dye spring and yarn wound on dye spring Carrier of the dyeing machine

The carrier has a loop in the centre, that can be hooked to the overhead bridge crane

Soft packages are loaded on spindles and locked at the top

Crane carries the carrier and inserts it in the dyeing vessel

Figure 5.1 Process of yarn dyeing in a HTHP dyeing machine

The dyeing machine has one main tank, one dosing tank and one preparation tank. The material is loaded to main tank. The colour solution shall be put in the dosing tank. The preparation tank shall be filled with water, which shall be heated and kept ready for use as needed.

60

Handbook on Fabric Manufacture

During the operation, the dye liquor moves from inside out and outside in number of times while keeping the yarn package intact on the spindle. The process can be programmed in the machine

Figure 5.2 Flowing of dye liquor in HTHP dyeing machine

The processes programmed shall be as per the requirement of the customer and the product. The normal processes are full bleach, reactive dyeing in light, medium or dark shades, vat dyeing in light, medium or dark and disperse. After the process is over, the cheeses are taken out and hydro-extracted to remove the excess water, and afterwards are dried using a radio frequency dryer. Different sizes of HTHP dyeing machines are installed in a dyeing factory to dye lots of different sizes. This helps in optimising the dyeing as per lot size and reduce the consumption of liquor and generation of effluents.

5.2

Purpose of yarn dyeing on HTHP machine

a. To process the loosely wind yarn packages on perforated tubes/ springs to get the required shade using a high temperature high pressure package dyeing machine. b. To maintain the uniformity of shade with required depth to suit the requirement of fabric to be woven or knitted. c. To dye the required number of yarn packages in each shade of a given design and deliver them together. d. To achieve optimum utilisation of water, steam, colours and chemicals resulting in lowest possible cost as well as minimum discharge of waste water. To summarise, ensuring effective processing of yarns in packed forms like dyeing and bleaching, working of HTHP dyeing machines and getting uniform dyeing quality, drying using hydro extractors and radio frequency driers.



HTHP yarn dyeing

5.2.1

61

What HTHP yarn dyeing should do?

a. Producing required number of yarn packages in each shade required for a design and delivering them together. b. Achieving uniform shade between packages and within packages of a lot. c. Achieving consistency in shade between lots of the same shade. d. Ensuring minimum consumption of colours, chemicals, water and steam for the shade being dyed.

5.2.2 a. b. c. d. e.

What HTHP yarn dyeing should not do? Dyeing more yarn packages than required for given design. Keeping dyed cheeses in baskets or crates. Using a large vessel for dyeing small lots. Having more number of lots for the same shade in a given design. Reducing the strength and elongation of yarns by over treatment.

5.3 General activities of Yarn dyeing in HTHP machine a. Getting the requirements of the customer/warping/weaving regarding the number of cones required in each shade, the exact shade requirements and the finishing they prefer. b. Preparing lab dip with the help of laboratory and getting the shade matched. c. Sending the sample for customer approval wherever called for. d. Preparing the process parameters referring to the approved shade. e. Deciding on the vessel depending on the quantity to be dyed in a lot. f. Indenting for yarn with yarn godown or winding. g. Informing the soft winding section and getting the required number of soft cheeses wound with uniform yarn density on perforated tubes or collapsible springs. h. Preparing the dye recipe as per the process card developed depending on lab dip results. i. Cleaning the dye vessel thoroughly before loading the carriers. j. Loading the soft wound cheeses on carriers and locking the cheeses. k. Downloading the carrier into dye vessel.

62

Handbook on Fabric Manufacture

l. Setting the timing, temperature and pressure on the panel of dyeing machine. m. Processing the yarn in the dye vessel as per the set parameters and timing. n. Removing the cheeses after all the processes are over like scouring, dyeing, fixing, finishing, washing etc., and hydro-extracting them. o. Finally drying the hydro-extracted cheeses in radio-frequency drier. p. Sending the dyed cheeses for winding onto cones.

Hydro extractor

Radiofrequency dryer

Figure 5.3 Drying after dyeing

5.3.1

Standard operating procedure

Establishing of standard operating procedures, educating and training all those who are involved in the activities and displaying it in the work area are essential to ensure proper implementation. Following is an illustration of standard operating procedure, which may change from mill to mill. Activity

Responsibility

1) The laboratory shall dye small samples, match the shade and workout the recipe to be used and sends to incharge dyeing.

Lab incharge

2) Incharge dyeing indents gets the required number of soft wound packages from respective winding section.

Dyeing incharge

3) Grey yarn is brought to the department by loading helper as per the production plan given by yarn dyeing in-charge. This plan is based on the dyeing orders received from P.P.C (production planning and control section).

Loading helper

4) The density of the soft package is checked and accepted if density lies between 360 and 370 (gm/litre).

In-charge preparatory

5) The cheeses are checked and rejected if there is any ribbon formation visible on the surface of the cheeses. It is also ensured that traverse of the package are uniform and sit on tubes (perforated tubes) equally covered by yarn on both side. If tube is broken or having crack, such cheeses shall be rejected.

Loading helper

AQ: Please confirm whether the edit made in the sentence beginning ‘Establishing standared...’, is correct.



HTHP yarn dyeing

63

Activity

Responsibility

6) As per programme, packages are loaded in carriers. While loading the cheeses, number of cheeses and count are crosschecked with that mentioned on the planning sheet. In case of any discrepancy, it is checked with dyeing order.

Loading helper

7) Depending on the quantity to be dyed, dying machine of suitable capacity is selected. This is to reduce colour and water consumption and finally effluents.

Dyeing incharge

8) Verify the lot number, count, the material and supplier, and check with the programme given. Then, load the packages to be processed on the spindles of the carrier.

Helper

9) Lock the spindles using gravity locks/lock plates.

Helper

10) Loaded carrier is then transferred to respective yarn dyeing machine with the help of crane.

Helper

11) Make use of the bridge crane and load the carrier in the dye vessel.

Helper

12) Close the lid after loading the material.

Helper

13) Ensure there are no leakages.

Helper

14) Fill the water in the preparation tank and start heating.

HTHP M/c operator

15) Green card or drug sheet is prepared for the shade which is to be dyed through system, which contains all the necessary information for the programme to be executed for yarn dyeing.

HTHP M/c operator

16) Green card remains on the machine till the dyeing is over.

HTHP M/c operator

17) Prepare the colour as per the recipe given and put in the dozing tank.

HTHP M/c operator

18) Select the programme depending on the type of process, viz. full bleach, reactive light, reactive medium, reactive dark, vat light, vat medium, vat dark, disperse and feed the correct programme in the micro processor.

HTHP M/c operator

19) Check points at pre-treatment stage: a) uniform absorbency less than 3 seconds b) core pH:6.5–7.0 c) whiteness index: visual assessment Start dyeing if all the above parameters are okay

HTHP M/c operator

20) Start and run the machine as per programme.

HTHP M/c operator

64

Handbook on Fabric Manufacture

Activity

Responsibility

21) Check points at dyeing stage: • pH of dyeing bath: 10.8–11.2 for cotton and pH of 4–5 for polyester • Temperature as per the set dyeing programme • Check shade with the standard; if found ok it should be finished • pH of finishing bath:5.5–6.5 • Before unloading the carrier, check few packages visually whether the levelness is okay or not.

Quality control

22) After the process is over, allow the machine to cool and reduce pressure.

HTHP M/c operator

23) Open the lid. By making use of the bridge crane, lift the dyed material carrier. Take the carrier to the material unloading area and bring down the hoist.

Helper

24) Unload the carrier at the specified unloading area.

Helper

25) Remove the wet material and load onto a pegged trolley.

Helper

26) Load the materials into hydro extractor and rotate for 15 minutes. Remove the packages and again load onto the pegged trolley and bring to radio frequency drier (RFD).

Hydro extractor operator

27) Before starting radio frequency drier, clean the air filter. Start cooling tower first and then blower and steam. Wait for 5 minutes and then start the drier.

R.F.D operator

28) Keep the material to be dried on the slowly moving conveyor of the drier. Set the speed as prescribed by the dyeing in-charge in case of different count or else run with the set speed in metres per hour as follows: a) 85KW – RF – 6.3–6.8 b) 100KW- RF – 7.2–7.6 c) The material shall enter the drier and comes out after drying from other end. Remove the material after it comes out.

R.F.D operator

29) Before stopping the radio frequency drier, stop the drier first and then steam and blower. After five minutes, stop the cooling tower.

R.F.D operator

30) Remove the dried materials. Put them on pegged trolley, insert the process sheet and send to yarn winding section through yarn godown after getting approval from quality assurance department.

Helper

31) In case of processing polyester yarns, there is no need of radio frequency drier. Only hydro extracting is sufficient.

Helper



HTHP yarn dyeing

5.4

65

Knowledge required for HTHP dyeing

People engaged in yarn processing need to have knowledge of the following: a. Importance and functions of various mechanisms in HTHP dyeing machine, hydro extractor, RF dryer and operations of overhead crane. b. Knowledge of various dyes and chemicals used; their reactions with the materials being processed; the after effects of dyeing or processing and the safety aspects to be considered while handling the dyes and chemicals. c. Preparing lab-dip samples, matching the shade and appropriately deciding the process parameters for bulk dyeing. d. Setting and monitoring the process parameters on HTHP dyeing machines, hydro-extractors and RF drying machine. e. Testing of dyes and chemicals for their purity. f. Preparing the dyeing recipe as per requirement.

5.5

Routine activities of yarn dyeing supervisor

a. Taking charge from the previous shift supervisor regarding the machines working, materials and lots working, problems faced, pending works and specific instructions and getting a general feel of the problems encountered and being encountered. b. Discussing with in-charge of dyeing operations and understanding the priorities of orders in yarn dyeing and the works to be carried for the shift. c. Understanding the production plan, production being achieved and allocating the vessels for different lots and shades within a design as per the priorities of warping/knitting or marketing by coordinating with them. d. Coordinating with yarn godown and getting the required yarns as per plan and in time. e. Planning for the activities including indenting for materials required for the shift considering the production efficiency being achieved not only in dyeing vessels but also in RF dryers and hydro extractors. f. Allocation of the workmen on the machines considering their skills and capabilities, monitoring their works and counselling them for improving their performance. g. Guiding for loading carries for different dyeing operations and machines.

66

Handbook on Fabric Manufacture

h. Checking the count of soft yarn, lot number etc., before loading on to spindles. i. Checking locking of spindles before allowing the materials in dyeing vessel. j. Getting dyeing recipe prepared from the colour man as required. k. Going through the process card and setting the process parameters and timing. l. Monitoring the pH of the dye bath. m. Keeping defective packages separately and informing the dyeing in-charge. n. Monitoring the production with quality and smooth working of the department. o. Ensuring that the condition of the machine is maintained for getting the quality and production as needed. p. Ensuring that all safety gadgets are utilised properly all the time for operating the machines and while transporting the materials. q. Ensuring that the waste water is discharged after proper checking and recording. r. Recording the stoppages of each machine reason-wise and working out the production loss due to stoppages. s. Recording the activities in log book giving details of lots and machines worked, people engaged, production achieved, problems faced and productions to be achieved in each order, stock of feeding material, stoppages and special instructions. t. Reporting to in-charge of yarn dyeing regarding the activities and performance of the department on daily basis and whenever required depending on the situation. u. Handing over the charge to next shift in-charge with clear instructions, clean work area and proper identifications on the materials being worked.

5.5.1

Activity specific to loading and unloading

a. Discussing with the in-charge and understanding the materials to be received and to be despatched. b. Supervising the unloading activities and ensuring that the materials received match to the descriptions in the delivery challan. c. Marking the packed yarns with details as required for despatch.



HTHP yarn dyeing

67

d. Supervising loading operations and ensuring that the packages loaded are as per the order.

5.6

Control points and check points

It is essential to have clarity on the points to be controlled to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘Control Points and Check Points’ and display them in the work area so that the supervisors refer and follow.

5.6.1

Control points for yarn dyeing

a. The raw material (yarn) type and quality, dyes and chemical’s requirements for the orders received and placing indents. b. Deciding the number of soft packages needed for the design in hand, the deadline for getting the wound material and communicating to winding. c. Employing trained employees and educating them on the process sequence of each order. d. Reviewing the dyeing capacities and planning activities for the orders received for yarn dyeing. e. Verifying the availability of dyeing machines of different capacities and the time taken for different dyeing cycles depending on the shade and dye combination. f. Planning the dyeing so that design-wise shade output can be achieved. g. The package dimensions required depending on the cheese holder capacity in dyeing machine, i.e., the traverse and maximum diameter. h. The soft package type (springs or perforated tubes) and density required, i.e., the weight of each soft package for the diameter and traverse (grams per litre). i. Identification to be put on dye tubes by mutual agreement with the dyeing and winding. j. The number of cones to be loaded per lot depending on the order size and the capacity of the HTHP dyeing machine. k. The water quality, the softness, turbidity and purity to get the required results. l. The dye recipe required.

68

Handbook on Fabric Manufacture

m. Dye recipe preparation: a. Use of colour Kitchen. b. Providing the required containers, balances, stirrers and safety equipments. c. Deciding on the method and sequence of recipe preparation. n. The dyeing operation sequence, time, temperature, steam pressure, liquor ratio, number of cycles, number of washes etc. o. The after treatment depending on the dye and depth. p. The acceptance criteria for fastness, shade variation between and within lots, whiteness index in case of bleaching and the physical properties of final yarn.

5.6.2

Check points in arn dyeing

5.6.2.1

Raw material related a. Check the availability of soft packages of particular count prior to planning of particular batch. b. Check by keeping soft wound packages side by side under natural light to confirm whether the grey yarn received has uniformity in shade or not. c. Whether the quality of soft wound package, i.e., density, diameter and weight are as per requirement or not? d. Whether the quality of dye tube is as required? e. Check the soft package built to confirm whether the quality of winding is okay or not. f. Dye a sample, if necessary to ensure whether the sample gives uniform dyeing or not.

5.6.2.2

Machine related a. Check the hoist for its condition. Whether the hoist is suitable for lifting and transporting the carrier with load? b. Check whether the programme selected to HTHP machines are correct for each dye lot. c. Whether the quality of spindles in the carrier is okay without bends? d. Whether there is sufficient space between spindles and dye tube for liquor to flow? e. Verify whether the dye package compressor is functioning properly without disturbing the yarn coils or resulting in more wastes.



HTHP yarn dyeing

69

f. Check the condition of joints in pipes and ensure there are no leakages. g. Check the condition of gaskets at the lid and ensure they are not allowing for any leakages of steam or liquid. 5.6.2.3

Water related a. Verify the water hardness test report to confirm whether the hardness is within the limits of 15 to 25 ppm. b. Whether the pH of water received and the wash water are within the specified limits? c. Whether metal contents, especially of iron are within the specified limits in the raw water? [This check is very important during hot summer period] d. Check the turbidity of water used, treat with alum and then filter it to bring to normalcy. [This check is very important during rainy season]

5.6.2.4

Colours and chemicals related a. Before planning for any batch in yarn dyeing vessel, ensure that dyes and chemicals are available in sub store. b. Check whether the quality of chemicals and dyes are as per requirement. c. Verify whether the dyes and chemicals required are available or not. d. Check all chemicals and dyes being used for their expiry period. e. Check for the availability of alternatives and combinations for dyes and chemicals.

5.6.2.5

Colour kitchen related

a. Check the weight and measurement of dyes and chemicals. b. Verify the preparation of dye paste/liquor and ascertain whether it is as per laid out procedure or not. c. Check and confirm for lump-free paste preparation. d. Check for the cleanliness of containers before use. e. Verify the correctness of balances and measures. 5.6.2.6

Process related

a. Verify and ensure that recipe is ready for particular batch. b. Verify and ensure correctness and completeness of process sheet. c. Verify the calibration of steam pressure gauges, temperature controllers and timers.

70

Handbook on Fabric Manufacture

d. e. f. g. h.

Verify the percentage utilisation of dye vessel. Check for the fastness and confirm it as per requirement. Verify the pressure in dyeing machine; out-in and in-out flow. Whether the intermediate additions are done as per time? Whether rise in temperature and cooling time are followed as per process sheet? i. Check the condition of pH during different stages of process. j. Check the dyeing and fixation time and temperature maintained as per process sheet. k. Check whether finishing temperature and time are maintained as per process sheet. l. Check and monitor the water consumption. m. Get the residual chemicals in effluents checked by the concerned department. 5.6.2.7

Work practice related

a. Observe and verify the work practices followed as per standard operating procedures. b. Check whether all are using safety gadgets as required for yarn dyeing, colour preparation and material handling operations of the yarn dyeing section. 5.6.2.8

Final yarn related

a. Verify whether uniformity in shade is achieved in the lot. b. Check the fastness test results to ensure the required fastness properties are achieved. c. Verify and ensure adequate conditioning of cones after drying before giving it to winding or packing them in plastic bags. 5.6.2.9

Log book related

Check whether the required information are entered in the log book. For e.g., a. The number of machines working lot-wise and shade-wise. b. The men engaged for various activities. c. The production achieved. d. The reason-wise stoppages of the machines. e. The problems faced. f. Stock of yarn (count-wise) waiting to be dyed.



HTHP yarn dyeing

71

g. Stock of dyed yarn packages (count-wise) waiting for delivery. h. Special instructions if any. 5.6.2.10

Management information system related

Check whether the following information are entered in the system properly: a. The count and quantity of yarn received from soft winding/yarn godown. b. The date and time of receipt of yarn from godown. c. The stock of raw yarn count-wise waiting for dyeing. d. The stock of dyed yarn packages count-wise. e. Dyeing machine-wise production. f. Materials delivered to godown/next process. 5.6.2.11 General

a. Whether the steam pressure received and maintained are as per requirement? b. Whether the machine cleaning was done properly? c. Whether the department was handed over to you in a clean condition. d. How was the condition of your department when you handed over the works to next shift? e. Whether material safety data sheet was received for all dyes and chemicals, and displayed prominently for taking safety precautions.

5.7

Normal problems in yarn dyeing

Normal problems in yarn dyeing are the shade variation within cheeses, shade variation between cheeses, uneven dyeing, stains, improper shade or tonal difference between lots, poor fastness properties, brittle yarn, and strength drop after dyeing/bleaching and hard packages after re-winding.

5.7.1

Shade variation within cheeses

The normal reasons for shade variations within packages are variations in package density within the package, mix-up of yarns of different count/TPI/ cotton within the package, and package touching each other during processing.

5.7.2

Shade variation between cheeses

Main reasons for variation in shade between cheeses are variation in package density between cheeses and improper draining of liquor.

72

5.7.3

Handbook on Fabric Manufacture

Uneven dyeing

Normal reasons for uneven dyeing are improper preparation of dyeing recipe, inadequate wetting, inadequate steam pressure, inadequate temperature of dyeing, improper additions of chemicals and inadequate liquor ratio.

5.7.4 Stains There are number of reasons for stain, and the following are prominent ones: 1. Stains of rust and oil can come from the hoist while transporting yarn packages. 2. Stains can also come from the drier and can be controlled by proper cleaning of drier and drier filter. 3. The stains can also come due to other dyestuff particles on wet cheeses, which can be controlled by covering the empty cheeses with clean paper, cloth or a polythene sheet.

5.7.5

Improper shade or tonal difference between lots

The main reasons for getting shade difference between lots are improper weighing of colours and chemicals, improper dissolution of colours and chemicals, lack of control in the time of treatment and increase in temperature and pressures, improper matching of samples and shade, change in some of the colours or chemicals, and change in cotton lots.

5.7.6

Poor fastness properties

Improper washing resulting in non-removal of unfixed dye-particles, inadequate temperature and pressure during dyeing, variation in process parameters are the normal reasons for poor fastness properties. A wrong selection of dyestuff can also cause poor fastness properties.

5.7.7

Brittle yarn

Over drying of dyed yarn and inadequate softening agents while finishing are the main reasons for brittleness in the yarns. Waxing the yarns after dyeing shall reduce the brittleness of the yarns and reduces its friction value.

5.7.8

Strength drop after dyeing/bleaching

Normally, strength drop is seen in extra dark shades where the chemical reaction is severe. Improper washing and neutralization causes the fibres to tender



HTHP yarn dyeing

73

and loose strength. Presence of iron contents in water results in gradual tendering of dyed/bleached yarn. Re-processing of yarns to get the required shade normally results in lower strength and elongation of processed yarns. Over drying of yarns is one of the reasons for drop in strength.

5.7.9

Hard packages after rewinding

Higher moisture content, i.e., improper or inadequate drying is main reason for hard packages after rewinding. Excessive tension while winding also causes the hard packages to some extent.

5.8

Dos and don’ts for supervisor

Understand clearly what you are supposed to do without fail and what you should not do at any cost in yarn processing. Some examples are given below:

5.8.1 Dos a. Verify and understand the design requirements in detail before starting your work, i.e., number of cones required in each shade and the date on which the delivery is required for warping and weaving. b. Verify the calculations and assumptions made in process sheet before implementing. c. Stick to colour codes and other identification system agreed between sections. d. Work for getting maximum utilisation of vessel capacity and efficiency. e. Insist and ensure use of gloves and gum shoes while handling chemicals. f. Check the condition of carrier and ensure it as good. g. Insist and ensure use of water shower for washing face and eyes. h. Insist and ensure use of gum shoes for the men working in wet area. i. Insist and ensure use of helmets for people working under overhead cranes and moving carriers. j. Get the dye vessels cleaned thoroughly after completing dyeing of each lot. k. Check and get the leakages in steam, air and water pipes without delay. l. Before starting dyeing machine, check the main water, air and steam valve; whether open or not.

74

Handbook on Fabric Manufacture

m. Ensure at pre-treatment stage the uniformity in absorbency at less than 3 sec, core pH between 6.5 and 7.0 and whiteness index by visual assessment. n. Check the pH of the dye bath and ensure it is between 10.8 and 11.2 and pH of finishing bath between 5.5 and 6.5 for dyeing cotton yarns. o. Give only the hydro-extracted yarn packages to the radio frequency dryer. p. Verify the lot number, count and supplier before loading the soft packages on to the carrier. q. Take all packages of a single lot number of the supplier for dyeing one lot. r. Verify the cheese quality, cheese density, and the condition of perforated seat on tubes before loading. s. Check the programme to be selected before starting the process. t. Follow the recipe and the process exactly as instructed.

5.8.2 Don’ts a. Do not draw or produce more material than the design requirements specified. b. Do not increase or reduce time, temperature, pressure, liquor ratio, quantity of colour and chemicals or the packages without the permission of dyeing in-charge c. Do not allow a machine to work if steam is leaking from it. d. Do not allow a machine to work if the pressure gauges are not operating properly. e. Do not allow a worker to work if safety gadgets provided are not used by him. f. Do not load the material without verifying the cotton yarn source and lot numbers. g. Do not mix two different lots of cotton yarn even though they are from same supplier and same count. h. Do not accept the cheeses having ribbon formation, broken seat on tubes or improper winding. i. Do not load the machine without locking the packages on the spindles tightly. j. Do not try to open the lid of a pressure vessel unless the pressure is completely released.



HTHP yarn dyeing

75

k. Do not give polyester yarns for radio frequency drier. l. Do not feed full wet material to radio frequency drier. m. Do not add any chemical or colour in between the process.

5.9

Responsibilities of supervisor in yarn dyeing

a. Completing the assigned jobs of yarn processing and achieving the production with quality as agreed upon besides maintaining the discipline, housekeeping and team working. b. Getting the machines started in time and achieving maximum utilisation of vessels. c. Ensuring clean working area all the time. d. Ensuring all materials and records are kept in their respective place. e. Verifying the yarn lot number before taking yarns for processing. f. Following up to get the soft packages of yarn in time. g. Checking the recipe sheet and preparing the recipe as needed. h. Ensuring that all machines are kept in good condition. i. Maintaining the samples and records relating to yarn dyeing. j. Reporting and taking corrective actions in time for the problems encountered. k. Ensuring that all the gauges and timers on the machines are calibrated in time and maintained properly. l. Ensuring safe handling of the packages and preventing damages and wastes due to poor handling practices. m. Taking corrective actions like getting the process settings corrected, getting the materials reprocessed, while limiting him to the authorities given to him. n. To help dyeing in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.

5.10

Authorities of yarn dyeing supervisor

a. Following up for grey yarns on soft packages required for dyeing. b. Rejecting the yarns received if found not proper. c. Getting the required colours and chemicals from stores by signing the issue slip. d. Following up with engineering section for getting the machines and other equipments rectified.

76

Handbook on Fabric Manufacture

e. Arranging for reprocessing of the processed cheeses in case of improper dyeing and informing to higher authorities. f. Stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions. g. Questioning the jobber and workers when the work done is not satisfactory. h. Informing HRD in case of lapse in discipline by any of the employee working under him. i. Allotting or changing jobs to workers considering their skills. j. Recommending leave and/or permission to the subordinates in the section.

5.11

Some hints for better performance

a. Always keep the working area clean, dry and tidy. b. Do not bring more yarn and keep in stock at dyeing section as it can lead to mix ups and misuse. c. Provide spare carriers and keep the cheeses loaded in advance before a running vessel completes its running lot and gets ready for next lot. d. Encourage workmen to work in teams rather than doing only some prescribed jobs individually.

6 Yarn singeing – yarn gassing

Figure 6.1 Singeing machine

6.1

Yarn singeing

Singeing is a process of removing superfluous fibres from yarn surface by burning them out. It is done either by using gas burners or electrical heating coils. This improves the smoothness of yarn. Singeing is done before subjecting the yarn for wet processes. Gassing is the name given for the process of passing yarn very rapidly through a series of Bunsen gas flames in a gassing frame to burn off the projecting fibres and make the thread round and smooth and also brighter. After gassing or singeing, the yarn passes through a box filled with water to prevent sparks or fires. Note: a. Only the high end superior qualities of yarn are gassed, such as that used for voiles, poplins, venetians, gabardines, many Egyptian qualities, etc. b. There is a loss of weight in gassing or electrical singeing, which varies’ about 5 to 8 per cent c. Normally, singeing is not done for single yarns as chances of breakage and bad quality is high. The doubled and multi-fold yarns are subjected to singeing operation.

78

Handbook on Fabric Manufacture

Figure 6.2 Yarn before singeing and after singeing

Yarn singeing machine consist a number of suitable sized gas jet burners or electrical heating coils equal to the number of packages to be handled at a time, normally in multiples of 24. The yarn passing from a big package is allowed for gas burning, but winding shall be on small packages for the purpose of safety. In case of electrical heating, temperature up to 1100˚C is obtained to burn the hairs.

Figure 6.3 Singeing operation

6.1.1

What Singeing should do?

• Remove superfluous fibres from the surface of yarn and improve lustre and feel of yarn. • Make the yarn bright by removing the hairs.



Yarn singeing – yarn gassing

6.1.2

79

What Singeing should not do?

• Should not burn the good yarn and create breaks and increase knots. • Should not change the colour of yarn. • Should not result in uneven singeing or uneven removal of hairs resulting in shade variations after dyeing.

6.2

Quality of singeing

Quality of singeing is measured by following methods: • Reduction in hairiness in the yarn. • Uniformity in singeing throughout the yarn. • Uniformity in the shade of the yarn; i.e., no yellowing of yarn due to excess burning.

6.3

General activities in yarn singeing

The general activities of a yarn singeing section may be listed as follows: a. Getting the requirement of yarn to be singied by the user department. b. Getting the required yarn from winding or yarn godown. c. Cleaning the singeing machine thoroughly before starting the works. d. Setting the heating elements in case of electric singeing. e. Setting the flame lengths, in case of gas singeing (gassing). f. Cleaning the surface of the cones to be singied by compressed air. g. Creeling the cones on the pegs. h. Starting the drums and then taking the yarn up through the guides, tensioners and wrapping on to cone above, before allowing the yarn to enter singeing element. i. Taking out the singed cones and sending for checking. j. Sorting and segregating the cones depending on the shade variations seen by naked eyes. k. Packing the cones and sending to next operation; normally yarn mercerising.

6.4

Knowledge required for singeing

Following are the essential knowledge one should have to look after singeing operations: a. Functions of different mechanisms in singeing machines.

80

Handbook on Fabric Manufacture

b. Maintenance of singeing elements like electric heating coils and gas burners. c. Setting of singeing elements. d. Controlling the singeing parameters like voltage in electrical coils, flame height in case of gassing and speed of winding. e. Safety precautions in singeing, especially prevention of fires while singeing. f. Maintenance and operation of firefighting equipments.

6.5

Precautions to be taken for singeing

Following precautions are to be taken while singeing: a. Precautions for preventing occurrence of fire. b. Providing firefighting equipments near to singeing machine. c. Providing training to all operators and workers regarding firefighting and safety. d. The singeing room should not have loose fluff accumulation, as it can lead to fire. e. Fluff accumulation should not take place near to burning elements, as it can lead to uneven flame heights and fires. f. The gas cylinders should be kept outside the singeing room in open area to avoid accidents. g. Singeing operations are not to be done along with other processes or in yarn godown. It should be done in a separate room isolated from other processes.

6.6

Control points and check points

It is essential to have clarity on the points to be controlled in singeing to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare their own ‘Control Points and Check Points’ and display them in the work area so that the people can refer and follow.

6.6.1

Control points

• Deciding the process parameters depending on the raw material and count.



Yarn singeing – yarn gassing

• • • • • • •

81

Speed of winding. Voltage to be set in case of electrical singeing. Height of flame in case of gas singeing. Delivery package dimensions. Providing skilled employees. Deciding on work norms and allotting people to work. Providing the required safety gadgets and firefighting equipments.

6.6.2

Check points

6.6.2.1

Material related

a. The count and ply of yarns received for winding and comparing with the production plan given. b. Quantity of material received and the quantity to be singied as per plan. c. The quality of wound packages received; if there are winding faults like stitches, sunken nose etc., there are chances of yarn stopping and getting burnt off. 6.6.2.2

Singeing machine related

a. Whether machine is cleaned well before starting the work? b. Whether the alignment of singeing elements is in line with yarn path without forcing yarn to touch any machine part? c. Whether winding drum, shaft, bearing, cone holders are in good condition. d. Whether the gas cylinders have sufficient gas to run in the shift. 6.6.2.3

Setting related

a. Whether the winding speed is as per plan? b. Whether the voltage/flame height is uniform and as per plan on all singeing elements? 6.6.2.4

Performance related

a. Whether the singed yarns have uniform shade within packages and between packages? b. Whether all the singeing elements are giving the same performance efficiency? c. Whether the reduction in hairiness is as planned? d. Whether the production is as planned?

82

Handbook on Fabric Manufacture

6.6.2.5

a. b. c. d. 6.6.2.6

a. b. c. d. 6.6.2.7

a. b. c. d. 6.6.2.8

a. b. c. d. e. f. g. h. i.

Documentation related

The lot number, contract number, count and quantity singied. The colour codifications used for identification of materials. The gas cylinders exhausted and replaced. Stock of yarn waiting for singeing. Work practice related

Whether the singed materials are properly marked as per plan? Whether the shaded materials are segregated from good material? Whether the gas cylinders are stored as per the safety regulations? Whether the surroundings of the singeing machine is always kept clean? Log book related The singeing machines worked. The men employed. Count, lot. Contract number and quantities singied on each machine. Instructions for next shift regarding the contract number, lot number, count and quantity to be singied. Management information system related

Date. Shift. Contract number. Count and material. Machine number. Quantity singied. Quantity approved as fresh quality. Quantity graded as seconds because of uneven shades. Operator.

6.6.2.9 General

a. Whether the workers employed are adequately trained? b. Whether the safety gadgets are in order and being used by all the employees? c. Whether the fire extinguishers are in order and kept at designated place?



Yarn singeing – yarn gassing

6.7

83

Normal problems in yarn singeing

The normal problems faced in singeing are as follows: a. Yarns going out of singeing elements at the time of attending breaks and resulting in unsinged portions. b. Yarns getting black or yellow (scorched) by touching the heating elements. c. Hairiness remaining at one side of the yarn especially with electrical singing. d. Loose fluff accumulating on burning elements resulting in the change of height of flames and also excessive breakages.

6.8

Dos and don’ts for singeing

Understand clearly what are supposed to be done without fail and what should not be done at any cost. Some examples are given below:

6.8.1 Dos a. Clean the singeing elements regularly and do not allow any blocking to develop. b. Check the height of flame and ensure that the height is maintained on all elements. c. Clean the incoming yarn cones with compressed air to remove all superfluous fluff. d. Check the quality of yarn and winding before taking it for gassing. e. Keep a watch on voltage and see that it is uniform. f. Always keep the firefighting equipment ready by the side of the machine.

6.8.2 Don’ts a. Do not take a low quality yarn with higher slubs and imperfections for gassing or singeing. b. Do not increase the height of flame or increase the voltage in electric element to improve singeing performance. c. Do not increase the speed to get higher production. d. Do not reduce the speed to get good singeing. e. Do not allow outsiders to touch the singeing machine.

84

Handbook on Fabric Manufacture

f. Do not engage untrained workers for singeing activities. g. Do not install singeing machine along with other machines in textile mill.

6.9

Responsibilities of supervisor in singeing

Following are the responsibilities of a supervisor in yarn singeing: a. Planning the activities considering the priorities of singeing and completing the work. b. Ensuring that singeing elements are set properly. c. Ensuring quality of singeing and getting minimum seconds/ rejections. d. Ensuring colour codifications followed as per the requirement of next process. e. Ensuring cleaning of machines and surroundings clean all the time. f. Ensuring adherence to the safety systems all the time. g. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline.

6.10

Authorities of supervisor in singeing

a. Authorised to reject a yarn lot if found with more uneven yarn or improper winding. b. Authorised to stop an element of singeing if the flame height is not proper or quality of singeing is not proper. c. Authorised to stop work if any leakage is found in gas pipes or in cylinders.

6.11 a. b. c. d.

Some hints for better performance Always keep the singeing elements clean and in good working order. Do not engage untrained workers for singeing. Do not accept singeing of a low quality yarn. Ensure good ventilation in the singeing room.

7 Yarn mercerising

Figure 7.1 Yarn mercerising machine

7.1 Mercerising Mercerising is one of the important process of giving special effects to cotton materials, both yarn and fabrics. It brings lustre to the fibre, increases hygroscopic property, strength and improves its dye affinity. This process was invented by a British calico printer ‘John Mercer’, which was called as mercerisation in his honour. The mercerisation consists treating of cellulosic materials with concentrated solution of caustic soda at required temperatures. Under the action of alkaline solution, chemical and structural modifications of cellulose take place. The material is immersed under tension in a cold sodium hydroxide (caustic soda) solution in warp or skein form or in the piece, and is later neutralized in acid. The process causes a permanent swelling of the fibre and thus increases its lustre. Sometimes mercerising is done only in relaxed condition, which helps in gaining strength and also improves dye ability, but improved lustre cannot be obtained.

86

Handbook on Fabric Manufacture

7.1.1

Changes during mercerising process

a. Fibre: 1. Swelling cotton fibres. 2. Cross sectional morphology changes from bean shape to round. 3. Shrinkage along with longitudinal direction. b. Molecular: 1. Hydrogen bond readjustment. 2. Orientation (parallelization) of molecular changes in amorphous region along the direction of fibre length. 3. Orientation of the crystallinity in the direction of the fibre length. c. Chemical: 1. Increased rate of reaction on hydrolysis and oxygen. 2. Liberation of heat during the caustic treatment (heat of sorption and heat of reaction). 3. Increase in the alkali absorption. The mercerising involves these three subsequent steps: a. Impregnation of the material in relaxed state in cold caustic solution of required strength and wettability. b. Stretching while the material is still impregnated in the caustic solution. c. Washing off the caustic soda from the material while keeping the material still in the stretch state.

7.1.2 Concentration, temperature and wet ability of mercerising lye For better and effective mercerisation, following parameters are considered as suitable: a. Caustic lye concentration = 300 GPL ± 20, i.e., 50 to 54˚TW b. Caustic lye temperature = 30 degree C ± 5. c. Caustic lye wet ability = Cotton yarn sinking time up to 5 seconds considered as good and 5 to 10 sec is acceptable.

7.2

Purpose of yarn mercerising

a. To provide strength and lustre to cotton yarns by treating with mild caustic soda solution under tension.



Yarn mercerising

87

b. To improve the dyeability of cotton yarns. c. To improve the dimension stability of cotton yarn.

7.2.1

What Mercerising should do?

a. Treating cotton yarns in hank form with mild caustic soda solution under tension. b. Neutralising the yarn after the treatment is over. c. Improve strength, lustre, dyeability and dimensional stability of yarn.

7.2.2

What Mercerisation should not do?

a. Should not damage cotton yarn by long exposure to alkali. b. Yarn should not get tendered by action of acid while neutralizing after caustic treatment. c. Treated water with chemicals should not be discharged without treating and neutralizing.

7.3

Quality of Mercerising

Quality of mercerising is measured by barium activity number. Mercerised sample absorbs barium hydroxide (alkali) to a greater degree than sodium hydroxide, and from practical point of view, barium hydroxide is easier to estimate. The ratio of uptake of this reagent has been referred as barium activity number. 2 gm mercerised and unmercerised samples are placed separately in two conical flasks containing 30 ml of N/4 barium hydroxide and left for 2 hours or preferably overnight. 10 ml of clear solution is withdrawn and titrated against N/10 HCl using phenolphthalein as indicator. A blank titration is also carried out on the measured barium hydroxide solution using Methyl red as indicator. Barium activity number = (b − s) × 100/(b − u) where b = ml required for blank test s = ml required for mercerised cotton u = ml required for unmercerised cotton For exact estimation correction should be made for moisture regain of the sample. Barium activity number of unmercerised cotton is considered as 100 and semi-mercerised cotton ranges from 115 to 130 and for completely mercerised cotton is about 155.

88

Handbook on Fabric Manufacture

Pulfrich Photometer, the Gorez Glarimeter comparative glass method and microscopic examination of cross section of fibre are qualitative methods for degree of mercerisation. This is not practiced in the textile mills. X-ray photograph of native cellulose (unmercerised) reveals presence of two arcs close together and inside the prominent 002 arc. Further analysis can be made to measure the level of mercerisation, but normally not practiced in textile mills. Determination of Infra-red crystallinity at different wave lengths is another method of measuring mercerisation. This method also not practiced in the mills.

7.4

General activities in yarn mercerising

Following are the general activities in a yarn mercerising section:. a. Getting requirement of yarns to be mercerised against various orders and their priority. b. Getting the required yarn for mercerising, may be singed or unsinged. c. Getting the yarn converted into hank form with required girth. d. Mounting the hanks on the mercerising machine. e. Preparing solution of caustic soda with required concentration. f. Treating the hanks in cold caustic soda solution under stretch for specified time. g. Taking out the caustic soda solution and washing with water. h. Neutralizing the washed hanks with an acid, normally acetic acid or light hydrochloric acid. i. Taking out the hanks and drying in hot air. j. Getting the hanks converted back on to cones by using a hank to cone winding machine. k. Sending the yarns for packing or to next process. Wetting power of mercerising lye can be improved by adding wetting agents. The quantity of wetting agent is optimised by the shrinkage, wetting/ sinking tests to get better wet ability at a given temperature and concentration. Lower additions of wetting agent will result in less shrinkage or wetting, thus lead to poor mercerising, and higher doses will increase the cost of ­manufacturing. Generally non-foaming, odour free, non-cresylic types of wetting agents are used in mercerising, which gives uniform wetting and better penetration of caustic liquor.



Yarn mercerising

89

General process flow in yarn mercerising can be illustrated as follows: Yam Twisting

Singeing

Reeling (hank makng) Mercenzing Bleeching

Neutralization

Dyeing HYDROEXTRACTION Drying Hank yam

Hank to cone

Figure 7.2 Process flow in yarn mercerising

7.4.1

Steps involved in one cycle of yarn mercerising

Following is an example. Depending on the equipment and the materials, the timings and activities may change. S. No Activity

Cycle time in seconds (approx.)

1

Loading cotton yarns hanks on the rollers in rest position

Depends on the quantity

2

Lowering of rollers to reach caustic tray

10

3

Moving caustic tray upwards – ready position to take caustic lye

4

Pre tensioning of hanks before starting

20

5

Free shrinkage and mercerising continued

90

6

Stretch during mercerising

20

7

Squeezing

20

8

Tray change from caustic to washing

10

90

Handbook on Fabric Manufacture

S. No Activity

Cycle time in seconds (approx.)

9

First hot wash and tensioning

20

10

Second hot wash

20

11

Third hot wash

20

12

Final cold wash

20

13

Squeezing

20

14

Lifting of rollers and downward movement of wash tray

10

15

Unloading of hanks

Depends on the quantity

Total cycle time in seconds other than loading and unloading

1. Hank loaded loosely on the mercerising rollers.

280

2. Hanks are stretched while being treated with caustic.

3. Hank in stretched condition after completion of washing.

Figure 7.3 Steps in yarn mercerising



Yarn mercerising

7.5

91

Knowledge required for mercerising

Following knowledge are essential for successful running of yarn mercerising: a. Basic knowledge of chemistry, the composition of cellulose, the reaction of caustic soda with cellulose under different conditions and concentrations, the reaction of acids on cellulose under different conditions and concentrations. b. Testing and titration activities to ascertain the strength of chemicals used. c. Basic knowledge of converting cones into hanks and hanks into cones. d. Importance of various functions provided in hank mercerising machine.

7.5.1  Significance of different steps in mercerising cycle 1. Pre tensioning: This is the first step in yarn mercerising cycle, which helps for uniform distribution of hanks on the rollers without any entanglement. The material should become completely wet in this step. 2. Shrinking: This is the actual caustic treatment step in which the yarn is allowed to shrink freely. The yarn hanks rotate in the caustic lye tray for sufficient time in relaxed state to react completely with caustic. Higher the shrinkage achieved better will be the mercerising. 3. Hank stretching: Hank stretching during mercerising or ‘lye tensioning’: The lye tensioning or stretching of hanks is done to stretch the yarn back to original length. This operation helps in improving the lustre of yarn. 4. Squeezing: It is done to remove the unbound caustic solution from the hanks/materials, so that the hanks/material can be washed effectively and quickly to reduce caustic content. This step also helps to control or minimise the wastage of excess caustic during washing. 5. Washing and tensioning: The stretch is applied to get the maximum lustre. Mercerised hanks are washed along with stretching beyond its original length (by about 4%) to get better lustre. The amount of stretch applied depends upon the lustre required and quality of yarn. The wash water temperature (Hot spray water) is kept near boil to make washing efficient and short. Time or sequence of washing is so adjusted to reach a residual caustic content below 10% within shortest possible time.

92

Handbook on Fabric Manufacture

6. Final caustic content: The final caustic content should be below 5%. If it is more, it will be sufficient to carry out further mercerising effect and the material will shrink back and loose the lustre. During the shortage of mercerised material, the water from the exposed areas will evaporate and get concentrated locally causing mercerising effect, which is called local mercerising, and this will lead to patchy dyeing during dyeing process. 7. The level of residual caustic: The level of residual caustic in the yarn is to be maintained less than 3%; if it is on the higher side then washing is not effective. It may require further washing.

7.5.2

Precautions to be taken for mercerising

a. Wearing safety gadgets like gloves, aprons and gum shoes while handling chemicals. b. Wearing mask when the chemicals are active and reacting with cellulose. c. Not storing alkali and acid together or side by side. d. Not to keep the chemical containers open to air. e. Ensuring that concentration of caustic soda does not exceed 5% after final washing.

7.6

Control points and check points

It is essential to have clarity on the points to be controlled in mercerising to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own “Control Points and Check Points” and display them in the work area so that the people refer and follow.

7.6.1

Control points

a. Deciding and selection of process parameters, viz., machine setting, mercerising time and temperature, stretch%, stretching time and temperature, caustic lye concentration, washing and neutralising sequences, batch size and liquor ratio. b. Deciding acceptance criteria for degree of mercerisation. c. Deciding on quality of raw materials to be procured.



Yarn mercerising

d. e. f. g.

93

Deciding on chemicals and their quality to be procured. Employing qualified and trained employees. Evolving production norms. Evolving norms for consumption of chemicals, water and steam.

7.6.2

Check points

7.6.2.1

Material related

a. Whether the raw materials, chemicals and auxiliaries are checked and ensured for meeting the acceptance criteria? b. Whether the raw materials like yarn hanks are as per the contract and programme? c. Whether the hanks are with the girth (circumference of the hank) and weight as specified? 7.6.2.2

Mercerising machine related a. Whether the quantity of material taken for a run is within the capacity of mercerising machine. b. Whether the condition of the machine is good and operates as per the programme set.

7.6.2.3

a. b. c. d. e. f. 7.6.2.4

Setting related

Whether the concentration of caustic lye is as required? Whether the wetting agents were added as needed? Whether the temperature of the caustic lye is maintained as needed? Whether the mercerising process cycle time is maintained as scheduled? Whether the stretch is maintained as planned? Whether the shrinkage set and actually achieved are as per requirement?

Performance related a. Whether the neutralising sequence is followed as per programme? b. Whether pH of neutralising liquor is maintained as specified? c. Whether barium activity number of the mercerised material is as per norms? d. Whether the production is achieved as per norms?

94

Handbook on Fabric Manufacture

7.6.2.5

Documentation related

a. The yarn details and the quantity received. b. Quantity to be mercerised and actually mercerised in each variety. c. Reprocessing done to make up the rejections. 7.6.2.6

Work practice related

a. Whether the people are following safety requirements all the time? b. Whether the machine is thoroughly cleaned after completing each run? c. Whether the chemicals are stored properly? 7.6.2.7

Log book related

a. Number of mercerising machines worked and the quantity mercerised in each lot. b. Stock of yarn to be mercerised and its details. c. Quantity of chemicals consumed. d. Problems faced in the shift. e. Special instructions for the next shift. f. Number of men engaged. 7.6.2.8

a. b. c. d. e. f. g. h. i. j.

Management information system related

Yarn count and details. Mercerising machine worked. Quantity of yarn received for mercerising. Quantity mercerised. Quantity approved as fresh quality. Quantity of yarn converted from hank to cones. Quantity of rework. Quantity rejected as seconds. Consumption of caustic soda. Consumption of acid.

7.6.2.9 General

a. Whether the men employed are adequately trained? b. Whether the consumption of chemicals, steam and water are as per plan?



Yarn mercerising

7.7

95

Normal problems in yarn mercerising

Normal problems in yarn mercerisation are as follows: a. Local mercerisation leading to patchy dyeing. b. Low barium activity number. c. Entanglements in the hanks resulting in more breakages while winding from hank to cones. d. When the mercerisation action is taking place, the temperature increases because of sorption. It is necessary to cool the bath to avoid damage to fibres.

7.8

Dos and Don’ts for mercerising

Understand clearly what you are supposed to do without fail and what you should not do at any cost. Some examples are given below:

7.8.1 Dos a. Check the quality of hanks received for mercerising. b. Check the concentration of caustic solution before feeding it to mercerising machine. c. Verify the process sheet before setting the process parameter on the mercerising machine. d. Check the weight of yarn before mounting it on the mercerising rollers. e. Ensure that the yarn is completely wet.

7.8.2 Don’ts a. Do not accept the yarn for mercerising if the hanks are found entangled while mounting on the mercerising rollers. b. Do not allow the temperature to increase while mercerising. c. Do not try to get fast results by increasing the concentration of alkali or acid. d. Do not stretch the hank beyond limits.

7.9

Responsibilities of supervisor in mercerising

a. Ensuring that the required quantity of yarn is mercerised with least rejections in spite of various problems being faced in the department.

96

Handbook on Fabric Manufacture

b. Ensuring that the mercerised yarn is got dried and wound on to cones and supplied to the user in time. c. Monitoring the consumption of chemicals. d. Recovering the caustic as much as possible for reusing. e. Ensuring all safety precautions are taken while handling chemicals and running the machines.

7.10

Authorities of supervisor in mercerising

a. Authorised to reject the yarn if entanglements are found in the hanks. b. Authorised to reject the caustic lye and the acids if they are found contaminated or weak. c. Authorised to question the operators when the quality or productivity is not as expected.

7.11

Some hints for better performance

a. Understand the process before deciding the process sequence or cycle. b. Check the purity of caustic soda and the quality of water before preparing caustic solution. c. Stick to the process parameters rather than trying to do some hasty things to increase production. d. Ensure that the hanks are fully wet before immersing in caustic solution.

8 Space dyeing of yarns

8.1

What is Space dyeing?

Space dyeing is a yarn-dyeing process in which each strand is dyed with more than one colour at irregular intervals. Space dyeing produces an effect of unorganised design in subsequent fabric form. There are different methods of space dyeing using knit-de-knit, warp printing, hank dyeing, cheese dyeing, etc.

8.1.1

Warp printing

In warp printing method, a warp sheet passes between pairs of printing rollers. Afterwards, the colour is fixed in a dye fixation unit. This operation is a continuous operation just like roller printing. This gives repeat effects.

Printing rollers

Warp sheet

Dye fixing unit

Warp sheet out

Space dyeing via warp printing for overall application

Figure 8.1 Warp printing

8.1.2

Hank dyeing

Space dyeing can be done on hanks using either single or multi-colour spaces along a given length in either a repeat or random pattern. When woven together, patterns can emerge depending on the length and variation of each colour block. This type of space dyed yarn is sometimes referred to as dip dyed yarn.

98

Handbook on Fabric Manufacture

The space dyeing of yarn involves the use of a special chemical called a mordant. The purpose of a mordant is to help permanently fix the dye to the yarn after the space dyeing process. Since different colours of dye require different types of mordents, this makes it possible to dye the same skein of yarn many different colours. Space dying can be done in either coordinating or contrasting shades. Space dyeing in coordinating colours, such as various neutral tones or assorted shades of blue, provides a subtle yet sophisticated look. Space dyed yarn in contrasting shades, such as purple, red and blue, offers a funkier feel. Space dyeing yarn allows one to create a multi-coloured colour-way in a single pot.

Figure 8.2 Space dyeing of hanks

8.1.2.1

Space dyeing of woollen yarn by hand

Following is an illustration of method employed for space dyeing of woollen hanks: a. Materials needed: Water, white vinegar, food colouring and 100% wool yarn wound into a skein and stove for heating. b. Set up the dye bath: Add 1 teaspoon of white vinegar per cup of water in the dye bath. Take water just enough to cover the yarn. c. Put the yarn to the dye bath before you turn on the heat. This will help reduce movement in the dye bath for when you add the dye so we get maximal separation between the colours. d. Turn off the stove after the dye bath is simmering. e. Drop food colouring into the pot, adding each drop in a different spatial area. f. Do not stir the pot. By stirring, the colours shall get mixed up and you will get one compound shade instead of different shades at different places. g. Let the yarn sit until all of the dye has absorbed to the yarn. If the skein is cool enough to touch, wash with lukewarm water and mild soap until the rinse water runs clear. h. Allow the skein dry.

Please edit the sentence beginning ‘Add the yarn...’ to have better readability.



Space dyeing of yarns

99

Figure 8.3 Space dyeing machine for cheeses

8.1.3

Space dyeing of cheeses

Space dyeing of cheeses is done by using a machine fitted with multiple colour tanks and colour pipes that are programmable to inject the required colour to the cheese as shown above. Following is an example of Space dyeing machine made by Om Sai Engineering. • The machine has 8 dye tanks as shown in the figure. Each tank has a separate injection pump. • Capacity of each tank is 30 litres and 80 cheeses can be dyed when tank is filled. • It has got different mould systems for different cone sizes. • The machine process is with cold dyeing system. • The machine is controlled by the time relay system. • In the process, multiple injections are provided to inject different dyes at a time and steam is forced in the vessel. • There are 48 pipes and 30 ml of colour is injected at a time from each pipe.

8.2

Purpose of space dyeing of yarn

The purpose of space dyeing is to ensure special effects of dyeing yarn at different spaces are produced on yarns effectively so that the fabrics produced out of it have delighting and decent fancy effects.

100

Handbook on Fabric Manufacture

Figure 8.4 Space dyeing machine parts

8.2.1

What space dyeing should do?

Space dyeing should produce yarn with differently dyed with either different colours or with varying shade, which can give a pleasant look to the fabrics may be woven or knitted.

8.2.2

What Space dyeing should not do?

• The colours should not get mixed up resulting in a single compound shade. • The colours should not bleed when in use.

8.3

Quality of space dyeing

There are no specified quality norms for space dyeing. “We do not guarantee repetition of shades or depth” is the claim made by space dyeing personnel.

8.4

General activities in yarn space dyeing

The activities in space dyeing (Cheese dyeing) are as follows: (i) Selecting the yarns to be dyed depending on the customer needs and/or design needs. Getting them wound on soft packages as per



101

Space dyeing of yarns

(ii)

(iii)

(iv) (v) (vi)

(vii)

requirement. The diameter of the soft package is very important; the package should be tightly held by the package holder. Hence, there is no tolerance for diameter in the negative side. Selecting the dyes and the blank bath recipe to be used for dyeing. Following is an example of blank recipe for Polyester filament dyeing: • 4.5% Printing paste –8 kgs • Acid buffer (colour tex PBI) 100 gms • Steaming accelerator [HTS] – 100 gms • Acetic acid [glacial] 50 gms • Levelling agent [PESI] 100 gms • Dispersing agent [WS] 100 gms • Water 100 litres Preparing the blank recipe: Take one mug of water of around 2 litres. Put 8 Kg of printing paste while stirring. After completing the printing paste, add PBI, HTS, Acetic Acid, PESI and WS in the same sequence. Keep stirring for minimum 10 minutes. Deciding whether coordinating or contrasting shades are to be developed. Deciding the colour recipe by referring to shades that are to be developed along with the proportion of blank bath to be used. Prepare dye recipe as per the recommendation of dye stuff manufacturers depending on the class of dye being used. Alternately, if the same combination has worked earlier, take the reference from that. Select the sequence of colours and put the liquor in respective tanks. An example is shown here for 4 colours in the ratio of 4:3:3:2 and with different combination of dye and blank. Shade

Liquid gm

No. of pipes

Ratio of self

Ratio of blank

D1

400

16

Full

Nil

D2

300

12

7

1

D3

300

12

3

1

D4

200

 8

3

2

(viii) Set the parameters on the machine: a. 51 seconds per package for operation,

102

Handbook on Fabric Manufacture

(ix) (x)

(xi) (xii)

b. Vacuum at 700 mm, c. Quantity of dye to be fed per injection pick up. d. Timing for vacuum 1st – 25 to 29sec and 2nd - 45 to 55 sec. e. Pick up 65% for warp 46% for bright tolerance ± 2%. Mounting the dye package in the machine and closing the lid. After mounting the package on the spindle, put the switch ON. The upper die (Cap) shall close first and then the outer die shall close and hold the package. The process shall start. After the set time, the package holder will open out followed by the cap. Remove the dyed cheese and feed the next one. After the operation in the space dyeing machine, do the curing. Load dyed yarn packages in the Ageing machine. Do the activities as follows (example): a. Loading 10 minutes approximate. b. While loading the cheeses, put brown craft paper on the top of each layer of cheeses. Top Plate Brown Craft Paper Dyed cheeses Bottom Plate

Figure 8.5 putting brown craft paper between cheeses

c. Heat and maintain 125˚C → 20 min for light shades, → 30 min for medium shades, → 35 min for dark shades. d. Cooling 20 minutes approximate. e. Reverse the package. Put fresh brown paper, Approximately 10 minutes. f. Heat at 135˚C for → 65 minutes for light shades, → 70 Minutes for medium shades, → 80 Minutes for dark shades. g. Cooling for 20 minutes approximate. h. Remove the cones - 10 minutes approximate. Keep steam pressure of 2 Kg/sq. cm. (35lbs/sq.in) (xiii) After ageing is over, close the steam valve and wait till the machine becomes cool.



Space dyeing of yarns

103

Figure 8.6 Steaming chamber after space dyeing

(xiv) (xv) (xvi) (xvii)

8.5

Remove the top lid and allow the steam to go out. After all steam has gone out, remove the cheeses. Give the cheeses for hydro extraction. After hydro extraction, send the cheeses for final hard winding.

Knowledge required for space dyeing

For space dyeing, one should have knowledge as follows: • Knowledge of complementary shades, contrasting shades and the way they behave when space dyed. • Different mordents and printing pastes that can be used for space dyeing. • Selecting different recipes depending on the customer’s requirements. • Selecting different proportion of colours to be injected. • Selecting the sequence of colour tanks and pipes. • The reaction of various chemicals on dyes and on the material being dyed.

8.5.1

 ignificance of different steps S in space dyeing cycle

a. Selecting the diameter of cheese; the cheese should not be loose when held by package holder. If the cheese is loosely held, the colours may spill out and the space dyeing effect shall not be proper in the outer and inner surfaces of the cheese.

104

Handbook on Fabric Manufacture

b. Preparation of blank recipe helps in proper and quick dyeing of yarn. c. Deciding whether coordinating or contrasting shades, based on the effect required in the fabric. d. Setting the parameters on the space dyeing machine to get the required shade and effect. e. Curing after dyeing to fix the colours.

8.5.2

Precautions to be taken for space dyeing

a. Preparation of cheeses with required dimensions, density and uniformity. b. Proper preparation of recipe. c. Putting brown papers on each layer of cheeses while curing to avoid dripping of colours from one cheese to other. d. Reversing of cheeses after half curing is done. e. Using gloves while handling chemicals. f. Covering the work surface with paper or polythene and wearing rubber gloves.

8.6

Control points and check points

It is essential to have clarity on the points to be controlled in space dyeing to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘Control Points and Check Points‘ and display them in the work area so that the people refer and follow.

8.6.1

Control points

a. The raw material type and quality, dyes and chemical’s requirements for the orders received and placing indents. b. Deciding the number of soft packages needed for the design in hand, the deadline for getting the wound material and communicating to winding. c. Employing trained employees. d. Reviewing the dyeing capacities and planning activities for the orders received for yarn dyeing. e. The package dimensions required depending on the cheese holder capacity in dyeing machine, i.e., the traverse and maximum diameter.



Space dyeing of yarns

105

f. The soft package type (springs or perforated tubes) and density required, i.e., the weight of each soft package for the diameter and traverse (grams per litre). g. The dye recipe required. h. Dye recipe preparation. i. The dyeing operation sequence.

8.6.2

Check points

8.6.2.1

Material related

• Whether the materials received are as per the programme. • Whether the cheese dimensions are as per requirements. 8.6.2.2

Machine related

• Whether the machine is in good condition. • Whether the colour pipes are clean and free for the colour solution to flow. • Whether the timers and controls are working properly in dyeing machine. • Whether the timer and controls are working well in ageing machine. 8.6.2.3

Setting related

• Whether the dyeing cycle set in the machine is as per the requirement. • Whether the quantity of colour per cycle set is as required. • Whether the time and temperatures set on ageing machine is as required. 8.6.2.4

Performance related • Whether the production achieved is as per planned. • Whether the space dyeing effect achieved is as per customer’s requirement. • Percent hard wastes generated in hard winding. • Whether colours and chemicals consumed are as per planned.

8.6.2.5

Documentation related

• The order number, shade number and the quantity dyed. • The recipe used. • The process timing and cycle set in dyeing and ageing.

106

Handbook on Fabric Manufacture

8.6.2.6

Work practice related

• Whether the dye tanks are cleaned well before filling colours • Whether the brown paper is put on each layer of cheese while ageing. • Whether the cone reversing was done after half ageing. • Whether the cheeses were sufficiently dried before sending it for hard winding. 8.6.2.7

Log book related

• The order number processed. • The material and count of yarn received and remaining to be received. • The quantity dyed and instructions for next shift for dyeing. 8.6.2.8

• • • • • • •

Management information system related Order No. Shade No. Yarn description. Number of cheeses dyed. Winding production completed. Quantity packed. Chemicals consumed.

8.6.2.9 General

• Whether housekeeping is good. • Whether the album of space dyed samples are maintained with details as needed.

8.7

Normal problems in yarn space dyeing

Normal problems encountered are as follows: • Choking up of any tube in dyeing machine resulting in less flow of a particular colour. • As the number of people working in space dyeing is very low, even one man not coming for work is a big problem. • Migration of colours from one place to another spoiling the space dyeing effect.



Space dyeing of yarns

8.8

107

Dos and don’ts for space dyeing

Understand clearly what are all supposed to be done without fail and what should not be done at any cost. Some examples are given below:

8.8.1 Dos a. Check the quality of cheeses received for space dyeing. b. Check the blank dyeing recipe prepared before feeding it to space dyeing machine. c. Verify the process sheet before setting the process parameter on the space dyeing machine. d. Select the sequence of colours and put the liquor in respective tanks. e. Prepare dye recipe as per the recommendation of dye stuff manufacturers depending on the class of dye being used. f. Reverse the packages when half curing is done. g. Put brown craft paper above the cheeses on each layer while curing. h. Use water shower for washing face and eyes. i. Use gum shoes while handling chemicals. j. Use gloves while handling chemicals. Cover the work surface with paper or polythene and wear rubber gloves; wash well after handling.

8.8.2 Don’ts a. Do not accept the yarn for space dyeing if the cheese diameter is less than required. b. Do not accept the cheeses if the traverse if not correct. c. Do not allow filling of tanks when dyeing operation is on. d. Do not try to get fast results by increasing the temperature of ageing. e. Do not touch the yarn bobbins by hand, and do not allow rough handling as the filaments shall slip and result in hard wastes especially while handling filaments.

8.9 Responsibilities of supervisor in yarn space dyeing a. Ensuring that the required quantity of yarn is dyed with least rejections irrespective of various problems being faced in the department.

108

Handbook on Fabric Manufacture

b. Ensuring that the dyed yarn is got dried and wound on to cones and supplied to the user in time. c. Monitoring the consumption of chemicals. d. Ensuring all safety precautions are taken while handling chemicals and running the machines.

8.10 Authorities of supervisor in yarn space dyeing a. Authorised to reject the yarn if ribbons are found in the cheeses. b. Authorised to reject the dyes and chemicals if they are found contaminated or weak. c. Authorised to question the operators when the quality or productivity is not as expected.

8.11

Some hints for better performance

a. Understand the process before deciding the process sequence or cycle. b. Check the purity of dyes and chemicals and the quality of water before preparing recipe. c. Stick to the process parameters rather than trying to do some hasty things to increase production. d. Ensure that the cheeses are of correct size to get proper grip by package holders.

9 Warping

9.1

Purpose of warping

A woven fabric is made up of two sets of yarn called as warp and weft. Warp is the set of yarn that run along the length of fabric and weft yarn goes across the width. Warping is the preparation of yarns for use as warp in a fabric. The required yarns are wound as a sheet with uniform tension. The purpose of warping is therefore to wind yarns parallel on a beam and prepare a sheet with required number of ends with the required pattern to get required effect on fabric and be a part of woven fabric.

Warp

We

Figure 9.1 Components of a woven fabric

Textile warping is the processing of creating the base yarn that runs top to bottom on woven cloth. Two types of warping are popular in textile industry for preparing warp for power driven high speed looms, viz., beam warping and sectional warping. Sectional warping is used when dyed yarns or yarns which do not require sizing are to be warped. The beam warping is normally used for grey single yarns or double yarns which require to be sized. In some mills, beam warping is used even for double and multi-fold yarns where sizing is not required, but weavers beam is prepared by using a dry tape machine, where different beams are just combined and final beam is made. Let us understand some terms in warping. • Creeling: The mounting of supply packages in a creel to feed yarn to a process like beaming or warping. • Transfer tail: A long end of yarn wound at the base of a package that permits increased warping or transfer efficiency by providing an easily accessible connecting point for the succeeding package. Earlier

110

Handbook on Fabric Manufacture

Creel Press roller Flanged beam

Figure 9.2 Schematic diagram of Warping

this system was in practice to increase the efficiency of warping. The system of having transfer tail is now discontinued in all quality conscious mills as it gives variation in yarn tension from full cones to the cones getting runout. • Beaming: The operation of winding warp yarns onto a beam usually in preparation for slashing, weaving or warp knitting. Also called warping. • Lost end: An end on a section or tricot beam that has been broken at some stage in warping and has not been repaired by a knot. • Reel: The large wheel in a horizontal warper onto which the warp sections are wound in the indirect system of warping.

9.2

Different types of warping

There are different types of warping, which include beam warping, sectional warping, beam to beam warping, draw-warping and ball warping. Let us try to understand the basic differences.

9.2.1

Beam warping

It is used for preparing warp beams suitable for feeding to sizing machine. Normally, beam warping is done for spun single yarns, and filament yarns those are needed to be sized and used for producing fabrics those are either piece dyed or going for printing. Beam warping is the process of creating the base yarn sheet with specified number of ends of specified count and pattern that runs top to bottom on woven cloth. A set of cones are creeled in warping machine and ends are taken together with a uniform tension in a sheet form and wound on a beam. Number of such beams is combined together in sizing depending on the number of ends required in the fabric.



Warping

111

Creel

Headstock

Figure 9.3 Modern beam warping machine

Modern beam warping machines have creels with moveable trolleys; inside with 8 rows and 5 stands in each holding 40 cones on each side. The trolleys are movable so that cones can be creeled in reserve when one set is working in the machine. There are 9 such moveable trolleys in working condition, so that 360 cones can be creeled on each side totalling to 720 cones.

9.2.2

Sectional warping

It contains a reel that is a large wheel in a horizontal warper onto which the warp sections are wound in the indirect system of warping. Number of sections required is decided on the design and the repeat. After all sections are wound on the reel, the wound sets are pulled out in the form of a single sheet and wound on the final beam. Hence, sectional warping is not a continuous operation, whereas beam warping is a continuous operation.

9.2.3 Draw-warping A process in which a number of thread lines, usually 800 to 2000 ends of POY feedstock, are oriented under essentially equal mechanical and thermal conditions by a stretching stage using variable speed rolls, then directly wound onto the beam. This process gives uniform end-to-end properties.

9.2.4

Ball warping

Ball warping is required to form the rope of yarn. It involves creeling multiple ends of yarn (Between 350 and 500 ends) and collecting them into an untwisted rope for dyeing. The rope is wound onto a long cylinder called a log on a machine called as a ball warper. The process is as follows: Packages of yarn are preconditioned before ball warping. They are loaded into the creel and placed on adapters. An adapter supports the package of

112

Handbook on Fabric Manufacture

Conventional sectional warping machine with beaming unit

Modern sectional warping machine with beaming unit

Figure 9.4 Sectional warping machines – modern

Creel Draw Unit

Guides

Finish Application

Inspection

Beaming

Figure 9.5 Draw warping

yarn and ensures that the package remains aligned to the tensioning devices. Wooden plug type adapter are most effective as they require least amount of exertion to remove the empty package. Next Step is threading the tensioner located at each yarn package. There are two types of tensioners, namely, Post & Disk tensioner and the driven disk tensioner. Post and Disk tensioner has two posts mounted onto a flat base. Two round disk are placed onto each post. The yarn is threaded between the disks and wrapped around the post. One of the parts is movable so that the angle of



Warping

113

wrap can be varied. More tension can be added to the yarn by adding round weights onto the top disk. They are inexpensive, do marginally adequate job of maintaining yarn tension, simple to thread up and requires low maintenance. The disadvantages are as follows: 1. Yarn has a tendency to jump out from between the disks at the rear of the creel. 2. It is labour intensive – when different tension levels are required. 3. There is more frequency of cleaning up 4. It does not control tension well at higher speed. 

Figure 9.6 Ball Warping

The driven disk tensioner also uses twin disk arrangement, however the disks are supported from below – there are no posts. Tension is applied from above – there are weights or spring loaded. A gear under each pair of disks is matched to another gear mounted on a continuous shaft which runs the length of the vertical tension post. This shaft is connected to a 4 rpm motor, which rotates the disk. Advantage of disk rotation is that it prevents thread cutting, dampening out variation due to ballooning action of yarn. The tension is more uniform and less effort is required to change tension levels. It has disadvantages like more difficult to thread up, more maintenance due to electric motor used and at high speed and the tension control is not well. 

9.2.5

Beam to beam rolling

Beam to beam rolling is used to repair a defective beam, which is either removed from a working loom or from a sizing. It is more ideal for preparing small lots of same fabric with several colours in warp sheet. It reduces yarn wastage in small lot sizing and helps increasing in loom efficiency.

114

Handbook on Fabric Manufacture

Figure 9.7 Beam to beam rolling

9.3

What warping should do?

a. To form from a predetermined number of single end packages, a continuous sheet of yarn of specified length and width. b. The individual ends of the sheet should be spaced uniformly across its full width. c. All the ends in the sheet should be wound at almost uniform tension. d. The density of wound yarn beam should be uniform across the width and from start to end of winding the sheet.

9.4

What warping should not do?

a. Attempt should not be made to remove yarn faults during the process of warping; the yarn breaks during warping should be as less as possible. Operation cost of an end break in warping shall be about 700 times of that in automatic winding. b. Density of the beam should be controlled not by increasing yarn tension but by adjusting the pressure of the beam on the drum or of the pressure roll on the beam in case of spindle driven beam. c. The yarn should not get damaged during warping. This can happen if the drum surface is not smooth and/or the parts in the yarn path have cut marks. d. The yarn sheet or the beam should not have faults, such as missing ends, cross ends, slack ends, fluff or wild yarn, high variation in tension between ends, damaged beam flanges, etc., which will cause end breaks or defects at subsequent processes.



Warping

9.5

115

General activities in warping

a. Getting the details of the design, pattern and length to be warped. b. Indenting the yarns with yarn godown or the winding section depending on the system followed in the mills. c. Cleaning the creel and creeling the cones as per the pattern given. d. Drawing the ends through the tensioners, thread guides and reed and wrapping on the warping drum. e. Warping section by section in case of sectional warping and full beam in the case of beam warping. f. Joining all sections and wrapping on final beam in case of sectional warping. g. Cutting the beam after the length is complete and doffing the beam. h. Weighing the warped beam and finding the net content by deducting the tare weight of the beam from the gross weight. i. Sealing the cut ends with a gum tape and attaching the beam card with details of design number, beam number, count, number of ends, beam length and beam weight. j. Sending the warp beams to next process, either sizing or drawing-in.

9.6

Knowledge required for running warping

a. Different types of warping viz., beam warping, ball warping, sectional warping, beam to beam warping and their purposes. b. Importance and functions of various mechanisms in warping machine. c. Knowledge of design and creeling cones as per design. d. Relation between cone weight, count and the yarn content in the cone. e. Importance of selvedge ends and creeling them. Workloads, work allocation and standard working conditions. f. Calculation of production and efficiency, the industry norms and factors affecting productivity in warping. g. Adjusting and monitoring tension of yarns. h. Importance of leasing and the method of leasing. i. Deciding process parameters like speed, tension, number of sections and number of ends in a section.

116

9.7

Handbook on Fabric Manufacture

Control points and check points

It is essential to have clarity on the points to be controlled in Warping to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘Control Points and Check Points’ and display them in the work area so that the people refer and follow.

9.7.1

Control points in warping

a. Selection of process parameters like: (i) Number of ends in the creel, (ii) Pattern of creeling the cones, (iii) Length of yarn in each beam, (iv) Warping speed, (v) Number of beams per set, (vi) Tension, (vii) Number of sections and leasing plan in case of sectional warping. b. Selection of design parameters like: (i) Material in the yarn, (ii) Type of yarn (single or doubled, compact or normal), (iii) Count of yarn, (iv) Shades of yarn, (v) Number of ends in each shade and their sequence (pattern), (vi) Total number of ends in the final warp beam, (vii) Number of ends in the creel, (viii) Number of selvedge ends and selvedge yarns, (ix) Length of yarn in each beam, (x) Number of beams per set, (xi) Creeling position of feed packages, (xii) Number of sections and leasing in case of sectional warping. c. Beam identification, i.e., information (specific points) to be written in beam card. d. Deciding the skill requirement and engagement of skilled employees. e. Deciding of work norms and allocation of workmen. f. Designing maintenance activities and implementing them.



Warping

117

g. Deciding and entering the required information in the log book like: (i) The machines allotted for different designs, (ii) The number of sections, (iii) The total number of ends, (iv) Ends per section, (v) Selvedge, (vi) Weight of empty beam and full beam, (vii) The warper engaged.

9.7.2

Check points in warping

9.7.2.1

Material related

a. Whether the feed material is as per plan, i.e., count, material (cotton/ PC/linen, etc.), shades, number of cones in each shade, and weight of each cone? b. Check the weight of cones looking very small compared to others and workout the available length. Use this figure as a base for setting the length on warping. c. Check whether the cones are creeled as per the pattern or not? 9.7.2.2

a. b. c. d. e. f. g. h. 9.7.2.3

a. b. c. d. e. f.

Warping machine related Alignment of creel pegs and the yarn guides. Condition of the ceramic guides and tension pins. Identification of tension discs with proper colour codes. Functioning of the stop motions. Functioning of the fans on the creel. Cleanliness of the yarn path and the machine. Functioning of the brakes. Condition of the empty beams. Setting related

Whether the cones are creeled as per plan? Whether the selvedge ends are drawn as per plan? Whether the number of sections taken is as per design? Whether the length set is as per plan? Whether the set length was obtained in the last section? Whether the speed is maintained as per plan?

118 g. h. i. j.

Handbook on Fabric Manufacture

Whether the tension set is as per plan? Whether tension is maintained uniformly on all ends? Whether the width of the set is obtained as per plan? Check and ensure there are no over lapping of yarns in the final beam.

9.7.2.4

Performance related a. Check the breakages to ensure whether the breakages are within norms. Observe the breaks for different component yarns, like shades and components. b. Whether the machine is giving the required production? c. Whether the machine is giving required efficiency? d. Whether the cone running out is uniform on all cones?

9.7.2.5

Documentation related

a. b. c. d.

Whether the beam cards are entered with all relevant information? Whether the beam weights are uniform and as per calculation? Whether the data of each warp beam was entered in the records? Whether the beams were sent to next process with proper memo and documentation? e. Whether the remnant cones are counted, weighed, recorded and returned to yarn godown/winding with proper memo? 9.7.2.6

Work practice related

a. Whether the workers are following the material handling systems as per requirements? b. Whether the tenters are putting the correct type of knot while mending breaks? c. Whether the unused materials are removed in time from time to time? d. Whether the machines and surroundings are kept clean all the time or not? e. Whether the spare creels are loaded and kept ready for next beam while the machine is working? 9.7.2.7

Log book related

Check whether the following information are entered in the log book: a. The machines allotted for different designs. b. The number of sections, the total number of ends, ends per section, selvedge details, weight of empty beam and full beam, the warper engaged and the beam count for each warping machine.



Warping

119

c. Stoppages with reasons for stoppages. d. The problems faced like short of materials, materials not received in time, uneven running out of cones in the creel and quality related issues. 9.7.2.8

Management information system related

a. Check for the correct entry of following data in the system: (i) Design No., (ii) Warping Machine No., (iii) No. of sections, (iv) Ends per section, (v) Selvedge ends, (vi) Total ends, (vii) Total length of beam, (viii) Nominal count, (ix) Weight, (x) Beam count, (xi) Date and time of production, (xii) Date and time of issue to sizing, (xiii) Remnants returned to godown. 9.7.2.9 General

a. Whether the temperature and humidity are maintained as per requirement? b. What is the quantity of hard wastes generated? c. Whether the hard wastes generated are within the norms? d. Whether the machine cleaning was done properly by the maintenance people? e. Whether you received the shift in a good condition? f. How was the condition of your section when you handed over the shift to next person?

9.8

Normal problems in warping

Following are some of the normal problems related to warping: a. Variation in tension within and between beams. b. Missing ends.

120 c. d. e. f. g. h. i.

9.8.1

Handbook on Fabric Manufacture

Cross ends. Poor quality of beam preparation. Production loss due to some cones running out early. Pattern not proper. Lost end. Section mark. Draw back.

Variation in tension within and between beams

Normal reasons for variations in tension are changes in balloon heights as the cones run out, reduction in unwinding diameter of the package as the unwinding progresses, the difference in the lengths of yarn between respective first thread guide and the head stock, the number of guide points for the yarn in the creel, the angles of deflection in the path of yarns from the axis of the respective packages to the first guide roll in the headstock and variations in the weight of tension discs and package diameters.

9.8.2

Missing ends

Normal reasons for missing ends are improper functioning of stop motions, bent drop wires, fluff accumulation in stop motions and entanglement of broken yarn with drop pin

9.8.3

Crossed ends

A crossed end is an end broken during warping that when repaired was not free or was tied in with an adjacent end or ends overlapping the broken end. The end draws or pulls back when unwound on the slasher. A crossed end is also referred as draw back. Normal reasons for cross ends are broken ends not drawn correctly and improper insertion of lease rods.

9.8.4

Poor quality of beam preparation

a. The build of the beam should be firm, which can be achieved by uniform tensioning with required weights. b. The surface of the yarn building on beam should be even and free from ridges from one selvedge to another. c. Ensure uniform spacing of comb dents, matching the comb width with the beam width, minimum variation in tension within and



Warping

d. e.

f.

g.

h.

121

between ends, matching of distance between beam flanges with the length of the drum and concentricity of beam flanges. The yarn sheet from the beam at subsequent processes should unwind smoothly without entanglements and breaks. Ensure effectiveness of stop motion and brakes, proper mending of broken end without introducing kinks snarls or cross ends, good condition of beam flanges and proper working of creel fans. The yarns in the beams should not have any frictional damages, for which ensure the following: a. Smooth surface of the drum, b. Absence of cuts in parts of the machine coming in contact with yarns and c. Suitability of warping speed for the type of yarn and the count. All the warper’s beams in a set, or all sections in sectional warping should have same length of warp sheet, for this the length measuring system should be accurate. During unwinding of beams, there should be minimum variation in tension from start to finish, for this the prescribed minimum diameter of the barrel is to be maintained.

9.8.5 Production loss due to some cones running out early Although length measuring units are fitted in winding, all cones shall not have same length and some cones run out early resulting in stoppage of machine and increase in hard wastes. You can solve the problem by following methods: a. Where same yarn is used for warp as well as for weft, creel full cones in warp and after the beam is taken out, send the remnants to weaving as weft. b. Keep some cones of 20 Gms, and use them to replace the run out cones, instead of taking out some cones from warp creel for rewinding and keeping the warping machine stopped till rewound yarns are received.

9.8.6

Pattern not proper

While creeling different dyed yarns in warping creel, care should be taken to creel exactly in the same position as per the design card, but sometimes there may be some mistake.

122

9.8.7

Handbook on Fabric Manufacture

Lost end

An end on a section or tricot beam that has been broken at some stage in warping and has not been repaired by a knot is referred as lost end.

9.8.8

Section mark

A fabric defect consisting of marks running warp wise in an evenly repeating pattern, caused by the improper setting of sections in silk system (or indirect) warping.

9.8.9

Draw back

A crossed end; an end broken during warping that when repaired was not free or was tied in with an adjacent end or ends overlapping the broken end. The end draws or pulls back when unwound on the slasher.

9.9

Dos and don’ts for warping

Understand clearly what you are supposed to do without fail and what you should not do at any cost in warping. Some examples are given below:

9.9.1 Dos a. b. c. d. e. f. g. h. i. j. k.

Verify and understand the design in detail before starting your work. Verify the input materials in detail and compare with the design. Verify the calculations and assumptions before implementing. Stick to colour codes and other identification system agreed between sections. Check the weight of the empty beam before mounting on the beaming machine. Check the quality of empty beam before taking it. Maintain uniform tension on all ends. Work for getting maximum utilisation and efficiency for which men are engaged. Have control on generation of hard wastes. Record/observe the wastes generated count wise, shade wise and material wise and analyse. Check personally the problems in working like loose ends, high breaks, etc., rather than depending on a third person.



Warping

123

l. Before setting the length on warping machine, check the weight of cones those are looking small compared to others and workout the available length of yarn on those cones. m. Check and ensure that creel peg and yarn guides are aligned properly for all ends. n. Check the pattern before starting to warp on drum. o. Check and ensure that all necessary warping details are written on the design card/beam card. p. Ensure that all the yarn in stocks are removed from warping area, which are not being used for the designs running on the machines.

9.9.2 Don’ts a. Do not change the pattern since it is not looking good to you. b. Do not engage people in the shift unless you have confirmed orders. c. Do not creel cones seen with uneven dyeing, ribbon, entanglement and bad cone built. d. Do not take the machine for creeling unless all the component yarns are received in full as per the design sheet. e. Do not draw or produce more than the ordered quantity. f. Do not keep any unwanted material near the warping machine. g. Do not accept to keep any material which is in the account of yarn godown in the production area as it can lead to misuse, misplacement, and mix-up, hindrance for movement, dust accumulation and damages to yarn.

9.10

Responsibilities of supervisor in warping

a. Completing the assigned jobs and achieving the production with quality for the designs working besides maintaining the discipline, housekeeping and team working. b. Ensuring that all the programmed machines are kept working. c. Getting the required cones for warping either from yarn godown or from winding as per the system followed in the mills. d. Verifying the yarn lot number and shades before the yarns are taken for warping. e. Getting the machines cleaned well before creeling the cones and starting the machine.

124

Handbook on Fabric Manufacture

f. Getting the machines started in time and achieving maximum utilisation. g. Ensuring proper housekeeping and clean working area all the time. h. Ensuring that all materials are kept in their respective places. i. Ensuring that records are kept in their respective place. j. Ensuring that the beam cards are entered with required information and attached to the beam. k. Taking corrective actions like getting the settings corrected, cones rewound, etc., while limiting self to the authorities given. l. Getting the hard wastes collected put in designated places and disposed after documenting. m. Ensuring safe handling of the cones and beams and preventing hard wastes due to poor handling practices. n. Supplying warp beams in time to user department. o. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline. p. Reporting HRD in case of any accidents and filling the accident reports in time. q. To help warping in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.

9.11

Authorities of supervisor in warping

a. Indenting and getting the required yarn as per design requirements. b. Rejecting the cones received if winding is not proper or too many breaks are found in any cone. c. Rejecting the cones received if the colour codification and labels are not as per the agreed norms. d. Questioning the jobber and workers when the work done is not satisfactory. e. Sending memo to HRD in case of a lapse in discipline by any of the employee working under him. f. Allotting or changing jobs of workers considering their skills. g. Rejecting empty warper beams if found to be of poor quality. h. Arranging for rewinding of the cones in case of remnants. i. Recommending leave and/or permission to the subordinates in the section.



Warping

125

j. Stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions.

9.12

Some hints for better performance

a. Always keep the warping area clean. b. Do not bring more yarn and keep in stock at warping section as it can lead to fluff accumulation, mix ups and misuse. c. Observe for repeated breaks in cones and attend to them, either by setting the tension or replacing the cone. d. Provide spare creel and keep the cones creeled in advance before running out of the cones in the running beam. e. Prepare some baby cones and replace the run out cones in the creel and avoid stoppage of warping machine for quick running out of few cones. f. Encourage workmen to work in teams rather than doing only some prescribed jobs individually.

9.13

Applicable formulae Beam Count Ne =

No of ends × Beam length in Metres × 0.9144 840 × 2.2 × Beam weight in Kgs

Or Beam Count Ne =

0.002395 × No of ends × Beam length in Metres Beam weight in Kgs

Length of yarn in cone in Mtr =

Ne × 840 × 0.9144 × weight of cone in gm 453.4

Or Length of yarn in cone in Mtr = 1.694 × Ne x weight of cone in gm

9.13.1 Method of working the expected production and the workloads Following table gives an illustration of working out production required, efficiency and workloads that can be given in sectional warping for operators, back attendant and helper.

126

Handbook on Fabric Manufacture

S. No. Front attendant work load

Time /operation in sec

A

To take charge from previous technicians in minutes

300

5.00

5.00

B

To receive instruction from Shift in-charge in minutes

300

5.00

5.00

Ca

Total ends

 

4120

2120

Cb

Metres set

 

765

300

Cc

Speed MPM

 

500

300

Cd

No of cones fed per section

 

190

200

C

Time to run one set in minutes = Cb/Cc

1.53

1.00

Da

Time to draw 100 ends through V reed and fixing on the section (To work with back attender)

5.00

5.00

D

Total time to draw the ends = (Da × Cd)/100

9.52

10.00

E

Number of leasing

3

3

F

Time for leasing

2.50

2.00

Ga

Breaks per section

0.60

0.20

Gb

Time to mend one break in minutes

2.00

2.00

G

Time to mend break per Section (Ga × Gb)

1.20

0.40

H

Total time for running one section(C + F + G)

5.23

3.40

I

Number of sections

21

10

J

Time for Completing all sections (H × I)

109.83

34.00

K

Beaming time per 100 Mtrs in minutes

320

5.33

5.33

La

Drum Leasing per 100 ends

300

5.00

5.00

L

Total Drum Leasing Time = (Cd × La)

9.52

10.00

M

Time for beaming ((Cb × K) × L)/100

40.90

16.10

N

Total selvedge ends

120

120

O

Time to draw selvedge ends

6.00

6.00

P

Time for leasing selvedge ends

7.00

2.00

300

 

120

 

 



Warping

S. No. Front attendant work load

127

Time /operation in sec

Q

Total time for completing one beam (D + J + M + O + P)

173.25

68.10

R

Number of beams expected for 720 minutes = (720/Q)

4.16

10.57

P

Work load per warper in minutes (D + (((F + G) × I) + L) × R) + A + B

377.01 379.47

Q

Total length warped per 12 hours (R × I × Cb)

66764

31718

R

Machine efficiency (Q/(Cc × 480)) × 100

27.82

22.03

 

190

200

102

1.7

1.7

3.238

3.4

Creeling time by Creel Boy D

No of cones fed per section

Ea

Time for removing the 100 remnant cones and cleaning the creel

E

Time for removing all the old cones and cleaning (D*Ea)/100

 

Number of remnant cones put in carton per minute

280

280

F

Keeping remnant cones in cartons

0.68

0.714

Ga

Time for creeling 100 cones

16.33

16.33

G

Time for creeling all the cones = (D × Ga)/100

31.11

32.67

H

Time for taking ends and combining 100 ends

456.00

7.60

7.60

I

Time to draw 100 ends through V reed and fixing on the section (To work with front attender)

100.00

16.67

16.67

J

Total time for combining and feeding through reed (I + H) × D/100

46.22

48.53

N

Total selvedge ends

120

120

O

Time to draw selvedge ends

6.00

6.00

P

Time for leasing selvedge ends

7.00

2.00

Total non-running time with in a beam

90.33

89.20

Ratio of idle time because of attending at back to total time

0.521

1.31

980

 

128

Handbook on Fabric Manufacture

Sr. No Back Attendant work load

Time /operation in sec

A

To take charge from previous technicians in minutes

300

5.00

5.00

B

To receive instruction from shift in-charge in minutes

300

5.00

5.00

C

Count worked – Ne

 

NA

NA

D

No of cones fed per section

 

560

560

Ea

Time for removing the 100 remnant cones and cleaning the creel

102

1.7

1.7

E

Time for removing all the old cones and cleaning (D*Ea)/100

9.52

9.52

F

Keeping remnant cones in cartons

2.00

2.00

Ga

Time for creeling 100 cones

16.33

16.33

G

Time for creeling all the cones = (D × Ga)/100

91.47

91.47

H

Time for taking ends and combining 100 ends

7.59

7.59

I

Time to draw 100 ends through V reed and fixing on the section (To work with front attender)

1.67

1.67

J

Total time for combining and feeding through reed (I + H) × D/100

51.82

51.82

K

Total selvedge ends

240

160

L

Time for creeling the cones = (K × Ga)/100

39.20

26.13

M

Total time for combining and feeding through reed (I + H) × K/100

22.21

14.81

N

Total work load = (E + F + G + J + L + M)

216.21 195.74

O

Number of creels could be done for 540 minutes (360-A-B)/N

980

100.00

 

2.45

2.71

10 Sizing

10.1

Definition and purpose

10.1.1 Definition of sizing Sizing is a generic term for applying various compounds to warp yarn to bind the fibre together and stiffen the yarn to provide abrasion resistance during weaving. Starch, gelatine, oil, wax and manufactured polymers such as polyvinyl alcohol, polystyrene, polyacrylic acid and polyacetates are employed. The warp yarns, during weaving, undergo number of stresses and strains due to up and down motion of healds in shedding, beating up by the reed, abrasion while passing through the droppers in warp stop motions, abrasion by heald eyes, reed wires, tension due to the action of let-off and take up operations in weaving. The stress is more as the speed of the loom increases. The height of shedding also has a contribution for the stress and strain on warp yarns. Therefore, it is necessary to provide warp with sufficient strength and resistance to abrasion, cyclic tensions and stresses. The purpose of sizing is to improve weavability of yarns by providing required strength, elongation and flexibility to the warp yarns and helping them to withstand the stresses and strains while working on looms. Sizing aims at the reduction of loom stoppages due to breakage of warp during weaving. The function of a sizing machine is to put a size on to the warp in the most suited manner to the particular type of fibre used, and to the ultimate fabric construction which enables the weaving operation to be performed without difficulty at a high rate of efficiency.

Creel

Drawing Waxing

Sizing Bath Eyelet

Inspection

Figure 10.1 Draw - Sizing

Dryers

Beaming

130

Handbook on Fabric Manufacture

Draw-sizing: A system linking draw warping and sizing in a continuous process. A typical system includes the elements like creel, eyelet board, warpdraw machine, intermingler, tension compensator and break monitor, sizing bath, dryers, waxing and winding units.

Schematic diagram of a multi-cylinder sizing machine

Creeling of sizing machine

Multi cylinder drying range

Sow box

Head stock of sizing machine

Figure 10.2 Multi cylinder sizing machine

10.1.2

What sizing should do?

a. Improve strength and elongation of the yarn. b. Improve abrasion resistance of the yarn. c. Reduce generation of static charges while working on looms at high speeds.



Sizing

131

d. Cover hairs of yarn to facilitate smooth movement in drop pins, healds and reed while weaving. e. Ensure uniformity in moisture content throughout the beam. f. Wind sized yarn sheet of required length with specified width on a beam with uniform tension.

10.1.3

What sizing should not do?

a. b. c. d. e.

Should not reduce the elongation at break of yarns below the norm. Should not excessively increase missing ends and cross ends. Should not produce sticky ends. Should not make the ends brittle. Size applied should not remain permanently on the yarn or stain the yarns permanently. f. Size applied should not create any problem while desizing. g. Size applied should not become hazardous or create problems of irreparable pollutions.

10.2

Quality of sized beam

A perfect sized beam should have the following: a. Ends wound straight and parallel to each other, with no rolled, crossed, stuck or lost ends. b. Uniform tension from end to end. c. Uniform warp density throughout the sized beam. d. Selvedge ends not high or low but flat with warp. e. Uniform application of size. f. The warp ends retaining required elasticity. g. Uniformity in moisture content. h. Absence of stickiness. The essential properties of a good size in the order of preference are as follows: i. Adhesion j. Film forming k. Solubility in water l. Wetting out m. Removability

132

Handbook on Fabric Manufacture

n. Moisture sensitivity o. Drying p. Size preparation q. Temperature stability r. Antistatic effect s. Good appearance It has been found that the weaving performance is greatly influenced by the abrasion resistance of the sized yarn. Abrasion resistance of a sized yarn depends on the uniformity and smoothness of the size film on the yarn. Both of these are governed by the viscosity characteristics of the size paste. Measuring and monitoring of viscosity using ISO viscosity cup is very essential.

Figure 10.3 ISO Cup

10.2.1 a. b. c. d. e. f. g. h.

Performance assessment of sizing is done by

Percent size add-on against planned. Moisture content of sized yarn and its variation. Single yarn breaking strength and elongation at break. Stretch on yarn during sizing. Lappers and migration of ends. Droppings at loom. Invisible loss of sizing ingredients. Lower end breaks and smooth working at weaving.



Sizing

10.3

133

General activities in sizing

a. Getting details of yarn, the number of ends and the weaving details like weave and type of loom, the speed at which it has to work and deciding the sizing recipe and the percent of size to be added. b. Working out the number of warp beams to be creeled and advising warping relating to number of ends per beam and the beam length. c. Deciding the sizing parameters, number of sow boxes to be used and number of drying cylinders to be used. d. Deciding the steam pressure and temperatures to be maintained on drying cylinders. e. Getting the warp beams. f. Creeling warp beams on the creel. g. Taking the yarn sheet forward with the help of leader sheet up to the expanding comb. h. Cooking the size and preparing the size solution as per the recipe decided. i. Washing the sow box and filling the size solution. j. Allowing steam to the cylinders and increasing the pressure. k. Starting the hot air exhaust fan in the hood above the drying cylinders. l. Denting the yarns through the reed and then winding on the bare beam. m. Putting lease rods. n. Starting the machine and monitoring stretch and moisture content. o. Doffing the beam after required length is wound on beam. p. Weighing the full beam. q. Entering the data as per the beam card and sending to beam gaiting. r. Returning the empty warper beams to warping section. s. Maintaining the records of beams sized, the recipe used, the consumption of size materials and stocks in hand.

10.4

Knowledge required for sizing

a. Importance of sizing. b. Importance and functions of various sizing materials, mechanisms in sizing and cooking machines and infrastructure in the section.

134

Handbook on Fabric Manufacture

c. Different types of sizing machines viz., Two cylinders slasher sizing, multi-cylinder sizing, infra-red drying in sizing, hot air drying in sizing and single end sizing and their purposes. d. Size recipe, single size recipe, properties of various components of size recipe. e. Working out size pick up and methods of controlling size pick up. f. Role of moisture content in maintaining correct weights. g. Factors affecting productivity in sizing. h. Safety, Legal and statutory requirements applicable to sizing operations. i. Procedure for preparing size recipe and maintaining the required viscosity. j. Monitoring the steam pressure, sow box temperature, the moisture content and stretch while sizing. k. Leasing and its importance. l. Denting the ends and adjusting the expanding combs.

10.5

Control points and check points

It is essential to have clarity on the points to be controlled in size preparation and sizing to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare their own ‘Control points and check points’ and display them in the work area so that the people can refer and follow.

10.5.1

Control points in sizing

a. Selection of design parameters like number of beams in the creel, total number of ends in weaver’s beam, length of yarn in each beam and the deadline by which the production is to be completed. b. Deciding process parameters like: (i) Sizing speed, (ii) Number of beams per set, (iii) Tension, (iv) Creeling position of feed packages, (v) Size recipe, (vi) Size pickup,



Sizing

135

(vii) (viii) (ix) (x) (xi) (xii) (xiii) (xiv)

c. d. e. f. g. h.

Temperatures of sow boxes, Temperature of individual drying cylinders, Steam pressure in individual drying cylinders, Squeezing pressures on different squeezing rollers, Steam pressure in steam inlet, Beam width, Leasing system, Number of drying cylinders to work and number of sow boxes, i.e., single or double, (xv) Whether waxing is to be done or not, etc. Beam identification and details to be written on the beam card. Engagement of skilled employees. Deciding of work norms and allocation of workmen. Designing maintenance activities and implementing them. Collection of wastewater and treating them. Collection of water vapours and wastes and disposing.

10.5.2

Check points in sizing

Material related a. Whether the warp beams received are as per the design requirement? b. Whether all the warp beams received are of identical length and weight or not? c. Whether the beams are creeled as per plan? d. Whether the empty beams are in good condition? Sizing machine related a. The condition of the sizing machine. b. The condition of the hoist/crane. c. The condition of the brakes for the creel beams. d. Whether the creel bearings are free or not? e. The condition of the reed and expansion comb. f. The condition and surface of the squeezing rollers. g. Whether Teflon coating on drying cylinders are good? h. Working of the exhaust above the drying cylinders. i. Condition of the steam and water pipe joints.

136

Handbook on Fabric Manufacture

j. Functioning of the moisture controller. k. Check the calibration of steam pressure gauge. l. Check whether the drainage below the sow box is clean and free. Size cooking and sow box related a. Whether the size recipe used is as per standard given? b. Whether the size is prepared as per sequence of size preparation plan? c. Whether the size paste was well prepared without lumps before cooking? d. Whether the stirrer is in good condition? e. Whether the size in stock is being continuously kept in rotation or not? f. Check for the removal of air from the air vent valve while preparing size paste in pressure kettle. g. Whether the temperature at sow box is constant and uniform as needed? h. Whether the viscosity is as per requirement? i. Whether the cooked size is continuously being heated with open steam or not? j. Whether the sow box was thoroughly cleaned while taking a new design? k. Whether the size cooking vessel was thoroughly cleaned before preparing fresh recipe? Setting related a. Whether the creel tension is uniform on all the sheets from each of the warp beam? b. Whether the squeezing pressure is uniform and as per requirement? c. Whether the length set is as per plan? d. Whether the speed is maintained as per plan? e. Whether tension and stretch are maintained as per plan? f. Whether the selection of drying cylinders is as per plan? g. Whether the size pick up is uniform and as per plan? h. Whether the denting is as per plan? Performance related a. Design wise productions completed and beams required for completing the order.



Sizing

137

b. Sizing machine wise performance. c. Whether the machine is giving the required production and efficiency? d. Whether the stoppages and breakages are within limits? e. Check whether the production of the previous shift is according to norms. Identify the root cause for low production and take preventive actions. f. Whether the size pick-up is as per the requirement? g. When waxing is a requirement, whether it is being done properly? h. Whether the sized yarn has required strength and elongation? i. Whether the moisture content in the delivered sized yarn is as per requirement? Documentation related a. Whether the beam weights are uniform and as per calculation? b. Whether the beam cards are entered with all relevant information? c. Whether the remnant beams are weighed and returned to warping with proper documentation? Work practice related a. Whether the workers are taking safety precautions and following the material handling systems as per requirements? b. Whether the draining of condensates is done as per schedule? c. Whether the beams and trollies are kept in their specified places? Waste monitoring a. Quantity of hard wastes generated – sized and un-sized. b. The hard wastes generated and the norms. c. Whether the wastes are monitored machine wise? d. Weighing, labelling and recording of wastes before sending it to waste section. e. Whether the steam and water consumption are as per norms? f. Collection and sending the wastewater for treatment. g. Disposal of the steam and water vapour. Log book related a. Check whether the sizing machines worked are entered properly with the design number, time of loading, number of beams taken out, the

138

Handbook on Fabric Manufacture

beam numbers allocated, the size recipe, actual size pick up in each beam and the men employed with their names and ticket numbers. b. Check whether the size recipe preparation book is entered properly with the weights of chemicals and water. c. Check whether the sizing record of individual machine is entered properly. d. Check whether the highlights of the findings of Q.A. is entered in the log book. Management information system related Check the following entries in the system: a. Design number b. Sizing machine number c. Date and shift d. Number of warp beams e. Total ends f. Beam numbers and the type of loom g. Length on each beam h. Weight of each beam i. Size pickup % of each beam j. Time and quantity of size recipe prepared k. Hard wastes generated – sized and unsized separately l. Date and time of issuing sized beams to drawing-in and looms General a. Whether the machine cleaning was done properly by the maintenance people? b. Whether the department was handed over to you in a clean condition. c. How was the condition of your department when you handed over the works to next shift?

10.6

Normal problems in sizing

• High size pick up • Low size Pick up • Uneven size pick up



Sizing

• • • •

139

Low elongation at break High moisture content Low moisture content Excessive lappers

10.6.1

High size pick up

The normal reasons for high size pick up are excessive pressure on squeezing rollers, slow speed in sizing allowing the yarn to remain for a longer time in sow box and use of more wetting agent than required. A higher size pick up can make the yarn brittle and rough, and also shall add to the cost of manufacturing.

10.6.2

Size pick up and fabric weight

In some instances, the weavers want more weight of fabric, and for that they insist on higher pick up, and the sizer adds weighting agents. This is not a good practice, as it reduces the life of loom parts. It is essential to work out the required count of yarn to get the prescribed weight per square meter of fabric, but the weavers go for finer count to get more length of fabric and end up with low weight per square metre of fabric.

10.6.3

Low size pick up

The normal reasons for low size pick up are as follows: a. Lower pressure on the squeezing rollers, b. A higher twist in the yarn, c. Improper preparation of size recipe, d. Lower temperature in sow box, e. Higher viscosity of the size and f. Insufficient time given for yarn to stay in sow box. A low pick up results in lower strength of yarn and hence can lead to breaks.

10.6.4

Uneven size pick up

The normal reasons for uneven size pickup are: a. Improper size preparation with undissolved parts, b. Improper addition of size into sow box,

140 c. d. e. f. g.

Handbook on Fabric Manufacture

Allowing the steam to condense in sow box diluting the size, Improper surface of rubber roller in sow box, Uneven pressure on squeezing rollers, Frequent stoppages of the sizing machine and Jerky motion.

10.6.5

Low elongation at break

Low elongation at break is due to excessive stretching of warp during sizing. Some sizers purposefully keep a higher stretch to get an advantage of higher length of fabric, but this leads to higher breakages at loom, and the loom efficiency drops down, and there shall be a big loss. It is essential to measure the stretch and maintain zero stretch to get a higher elongation at break, a good working of loom and a fabric with a good feel.

10.6.6

High moisture content

a. Low temperature of drying cylinders due to low pressure and condensation not removed periodically are the main reasons for high moisture content. b. High moisture content results in sticky ends, soft beam and higher breaks.

10.6.7

Low moisture content

a. Excessive drying results in low moisture content. b. Low moisture leads to brittle yarn and high breaks.

10.6.8

Excessive lappers

Excessive lappers are due to stickiness and high breaks while sizing. This leads to more migration of ends and cross ends, leading to higher breaks. High stretch also results in higher lappers and cross ends.

10.7

Dos and don’ts for sizing

It is essential to understand clearly what is supposed to be done without fail and what should not be done at any cost. Some examples are given as follows:



Sizing

10.7.1

141

Dos

a. Verify and understand the design in detail before starting your work. b. Verify the calculations and assumptions before implementing. c. Stick to codes and other identification system agreed between sections. d. Work for getting maximum utilisation and efficiency for which men are engaged. e. Check the condition of the beam and adjust the width between flanges before mounting the empty beam. f. Take round in the loom shed to check visually at least one beam alley per shift for working of sized beams in general and to investigate particular sized beams on the basis of complaints. g. Give feedback to warper by filling the complaints related to lappers, cross ends, loose ends, waste, loose and damaged flange etc., for warper beams along with the details of warper number, shift, type of complaint and action taken. h. Check the design number and the beam number before picking the warp beam for sizing. i. Check mending of lappers on the sizing machine. j. Check viscosity of size recipe by using ISO - 3mm viscosity cup k. Check the work practice of warper in warping section. l. Ensure wearing of helmet while operating the hoist and lifting the beams. m. Insist workers to wear helmet while operating the hoist and lifting the beams. n. Check the balance of size ingredients in stock. o. Check balance of sized beams before deciding on taking next lot for sizing. p. Ensure use of hook knife to remove the lappers from squeeze rollers. q. Ensure use of protective gloves while removing lappers from the squeeze rollers. r. Check the condition of squeezing rollers by taking impression at least once in a fortnight. Get the squeezing rollers buffed if the impression is not proper. s. Ensure uniform pressure on the squeeze roller on both the sides.

142

Handbook on Fabric Manufacture

t. Control the effluents, water consumption and steam consumption while achieving targeted production. u. Check and ensure that safety gadgets provided are operating properly. v. Check personally the pressure, temperature, stretch and moisture rather than depending on a third person.

10.7.2

Don’ts

a. Do not decide on beam identification codes by yourself. b. Do not draw or produce more than the ordered quantity. c. Do not change any process parameters of the machine or the beams to get more productions. d. Do not engage people in the shift unless you have confirmed orders e. Do not avoid taking round in loom shed and understanding the performance of beams on loom. f. Do not use the warp beam if the beam card is not entered properly. g. Do not allow the machine to run if the size level is very low and not properly touching the lower roller. h. Do not allow the machine to run if the pressure gauges are not functioning properly. i. In sizing machines with double sow box, do not keep a particular sow box always idle, as cracks are likely to develop in the surface of squeeze rollers. j. Do not pour dry powder directly into full water for preparing size. k. Do not allow lumps to form while preparing size liquor. l. Do not expose the Sizing chemicals to moist weather. m. Do not keep your creel dirty as it can lead to breakages in weaving because of fluff entanglement. n. Do not keep the beams below the oil box of the hoist as chances of oil leakage is there. o. Do not use a beam if the beam card is not entered properly. p. Do not allow more live steam in the sow box as it can dilute the size. q. Do not run the machine if the pressure gauges are not functioning properly. r. Do not use a squeeze roller with tapering or hollow effects s. Do not allow the size to become cool as it can lead to skimming.



Sizing

143

t. Do not allow the use of size if lumps are found in it. u. Do not allow use of a straight knife for removing lappers.

10.8

Responsibilities of supervisor in sizing

a. Understanding the sorts/orders to be sized. b. Deciding the size recipe and size pick-up percent required as per the quality of yarn, the number of ends and the weaving details like weave and type of loom, the speed at which it has to work. c. Checking the stock of empty beams and arranging further beams depending on the orders to be beamed. d. Preparing production plan considering the number of warp beams and set length. e. Allocating the sizing machines for different activities. f. Verifying the condition of beam flanges and getting them corrected. g. Verifying the weighing balance for its correctness by using standard calibrated weights before using for weighing. h. Ensuring that the warp beams are creeled as per the pattern required. i. Working out the size recipe and getting materials from stores as needed. j. Ensuring that the size cooking is done as per the size recipe suggested considering the type of yarn and the number of ends. k. Ensuring the size ingredients are stored and handled in a safe way. l. Ensuring the sow box is washed well before starting a new set. m. Ensuring that the tension is set and stretch is maintained as minimum as possible and uniformly. n. Ensuring that the steam condensates are discharged from time to time. o. Ensuring that the ends pass through the stop motion and reed. p. Ensuring that the steam pressure and the temperature are maintained. q. Ensuring that drying is uniform and adequate. r. Ensuring that the empty beams are weighed where weights are not written on beams and ensuring the weights are recorded before starting each beam. s. Ensuring the length set is correct as per the requirement of the beams.

144

Handbook on Fabric Manufacture

t. Working out the size pick up for each beam by weighing the full beams. u. Checking the productions of all sizing machines. v. Maintaining the Sizing record as per the requirement. w. Completing the assigned jobs and achieving the production with quality as agreed upon besides maintaining the discipline, housekeeping and team working. x. Ensuring that all the programmed machines are kept working. y. Getting the machines started in time and achieving maximum utilisation. z. Monitoring the effluents, water consumption and steam consumption while achieving targeted production. aa. Ensuring clean working area all the time. bb. Ensuring that all materials are kept in their respective place. cc. Ensuring that all records are kept in their respective places. dd. Verifying the warping beam number and design numbers before they are taken for sizing. ee. Getting the hard wastes collected put in designated places and disposed after documenting. ff. Ensuring safe handling of the beams and preventing hard wastes due to poor handling practices. gg. Supplying size beams in time to user department. hh. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline. ii. Reporting HRD in case of any accidents and filling the accident reports in time. jj. Helping sizing in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.

10.9

Authorities of supervisor in sizing

a. Authorised to issue sizing chemicals for size cooking after checking the recipe sheet and the weights of the chemicals. b. Authorised to question the workers when the work done is not satisfactory. c. Authorised to send memo to HRD in case of serious lapse in discipline by any of the employee working under him.



Sizing

145

d. Authorised to allot or change jobs of workers considering their skills. e. Authorised for recommending leave and/or permission to the subordinates in the section. f. Authorised for stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions.

10.10

Some hints for better performance

a. Remove the evaporated water particles from surface of drying cylinders effectively by exhausting them through hood. b. Periodically remove the condensed water particles from inside the drying cylinders. c. Always maintain the surface of the squeezing roller clean and plain. d. Do not heat the size bath in sow box using live steam. e. Ensure uniform squeezing pressure. f. Increase in squeezing pressure increases size pick up. g. Do not use a sharp knife to remove lappers from squeezing rollers, instead use hook. h. Keep minimum gap between threads and to the beam flange on the size beam and avoid yarns going in between the gap.

10.11

Applicable formulae

Size pick up% =

( Weight of sized yarn − Weight of unsized yarn ) ×100 Weight of unsized yarn

11 Basics of fabric structure

11.1 Weaves The fabric weave or design is the manner in which the warp and weft are interlaced. The pattern or repeat is the smallest unit of the weave which when repeated will produce the design required in the fabric. There are many ways of representing a weave, a most familiar method being to use square design paper. A house filled indicates that warp is in the top and a blank house indicates that weft is in the top. The warp ends are shown in vertical lines and weft in horizontal lines. There are innumerable fabric constructions and it is not possible to cover all weaves and types of fabrics in one chapter. We are discussing some basic constructions only. The form of interlacing of warp and weft yarns can be divided basically into three categories – plain, twill and satin/sateen weave. These three kinds of forms are called basic weaves.

11.2

Plain weave

In a plain weave, each warp yarn passes over alternate weft yarns. Neighbouring warp yarns pass over the adjacent weft yarns. The plain weave is the simplest and commonly used. In this type of weave, the warp and filling yarns cross alternately.

Figure 11.1 Plain weave

Some examples of plain-weave fabric are crepe, taffeta, organdie, and muslin. The plain weave may also have variations, which include the following: • Warp rib weave – Warp rib weaves may be described as plain weave in which two or more picks are inserted in the same shed.

Author: Please cite all figures in text.



Basics of fabric structure

147

In rib weaves the filling yarns are larger in diameter than the warp yarns. A rib weave produces fabrics in which fewer yarns per square centimetre are visible on the surface. Warp rib weaves are normally used in warp faced constructions. The warp cover factor and the warp crimp are substantially higher than the weft cover factor and the weft crimp. The intention is to produce fabrics with prominent weft-way rib formed by the crowns of the warp threads. • Weft rib weave – Weft rib may be described as plain weave in which two or more ends weave together as one. It is difficult to achieve very high weft cover factors in weft faced plain-weave cloths. By using two finer ends weaving as one, it becomes possible to achieve the higher weft cover factor. Such cloths are expensive to weave and not very common. • Basket, matt or hopsack weave – In matt, basket or hopsack weaves two or more ends and two or more picks weave as one. The simplest and commonest of these weave is 2/2 matt.

11.2.1

Basic basket weaves

Figure 11.2 Basic basket weaves

The three basic types of basket weaves are (a) plaited, warps and wefts are indistinguishable; (b) wicker, warps are vertical and wefts are horizontal; and (3) coiled, warps are horizontal, wefts vertical. •• Regular basket weave: This is commonly used for edges in drapery, or as a bottom in very small weave repeats, because the texture is too loose-fitting for big weave repeats; moreover, yarns of different groups can slip, group and overlap, spoiling the appearance. This is why only basket weaves 2-2, 3-3 and 4-4 exist. •• Irregular basket weave: This is generally a combination of irregu­ lar warp and weft ribs.

148

Handbook on Fabric Manufacture

11.2.2

Other plain weaves

• Wicker weaving techniques: (a) In plain wicker, wefts are passed over and under one, (see top figure, middle) or two warps at a time, then alternated in the next row; (b) In twined wicker, two wefts are woven one over and one under single warp elements, twisted over each other between warps, and alternated in the next sequence; and (c) The process in wrapped wicker is a literal wrapping of the weft element about each warp.

Figure 11.3 Wicker weaving technique

• Chiffon: A very soft and filling plain woven silk texture consisting of the finest singles which are hard twisted and woven in the gum condition. The cloth is afterward degummed. • Georgette: A cotton crepe fabric made in imitation of silk georgette, with hard twisted warp and weft yarn. A good cloth is woven plain with right and left twist thread arranged in 2 and 2 order in warp and weft. • Shantung: Coarse silk fabric with Slubs. Mostly Tussah Silk but can be polyester, nylon and viscose. • Seersucker: It is created by holding some warp yarns at tight tension, some at slack tension. Those at Slack Tension puff up to form a sort of Blister-effect, often slack and tight yarn of different colour. • Regular basket weave: This is commonly used for edges in drapery, or as a bottom in very small weave repeats, because the texture is too loose-fitting for big weave repeats; moreover, yarns of different groups can slip, group and overlap, spoiling the appearance. This is why only basket weaves 2-2, 3-3 and 4-4 exist. • Irregular basket weave: This is generally a combination of irregular warp and weft ribs. • Monks cloth: Heavy cotton cloth in a coarse basket weave, chiefly used for draperies.



Basics of fabric structure

149

• Oxford: Oxford weave fabric consists of two, thin warp yarns woven to very soft, thicker yarn in the filling direction. The unbalanced construction of the fabric causes the thin yarns to break and leave tiny holes. The primary use of oxford weave fabric is in cotton shirting. It is also used in other forms of apparel.

11.3

Twill weave

A basic weave characterized by a diagonal rib, or twill line which makes a pattern of diagonal lines. Each warp floats over more than one weft, at least two consecutive picks. Each warp yarn passes over (and/or under) more than one weft and adjacent warp yarns follow the same pattern, but are displaced by one cell. This is shown in Figure 11.4

Figure 11.4 Twill weave

These twill lines are produced by letting all warp ends interlace in the same way but displacing the interlacing points of each end by one pick relative to that of the previous end. In twill weave line moves sinisterly (Right– Left, Z twill) and dextrally (Left–Right, S twill). Twill weaves are more closely woven, heavier and stronger than weaves of comparable fibre and yarn size. They can be produced in fancy designs. Common derivatives of twill weave are as follows: • Zigzag weave – If the direction of the diagonal in a twill fabric is reversed periodically across the width, a zigzag effect is produced. Zigzag weave is achieved by simply combining two S and Z twill weaves of equal repeat. • Diamond weave – Diamond weaves are achieved by combining two symmetrical zigzag weaves of equal repeat. Diamond designs are vertically and horizontally symmetrical. • Herringbone weave – In Herringbone weave also the twill direction is reversed periodically like zigzag weave but at the point of reversal the order of interlacement is also reversed and then twill line commence as usual.

150

Handbook on Fabric Manufacture

• Diaper weave – Diaper weaves are produced when we combine two Herringbone designs. Diaper designs are diagonally symmetrical. • Denim: Heavy cotton twill made of coarse yarns. A strong warp face cotton cloth used for overall, Jeans skirts, etc. Largely made in 3/1 twill weave. Generally warp yarn is dyed dark brown or indigo blue and crossed with white weft. ``White back” denim, made with brown or blue warp and white filling. ``Double and Twist” means yarns are doubled and then twisted. Drapery denim is finer and has softer finish than overall denim; usually yarn-dyed and woven in small geometric figure. Uses of denim are couch covers, upholstery, hangings, slip covers and dress materials. • Gabardine: A warp face cloth mostly woven 2/2 twill, 27/2 tex warp, 20/2 tex cotton weft. Here cotton weft is yarn dyed but the wool warp may be dyed in piece. Shows raised cord on right side. The two types of twill plaiting are: (a) over-two-under-two; and (2) over-one-under-three.

Figure 11.6 Two types of twill plaiting

11.4

Satin/sateen weave

The satin weave is characterized by floating yarns used to produce a high lustre on one side of a fabric. Warp yarns of low twist float or pass over four or more filling yarns. The low twist and the floating of the warp yarns, together with the fibre content, give a high degree of light reflection. Weights of satin fabrics range from chiffon satin to heavy duchesse satin. The sateen weave is similar to a satin construction except that in the sateen weave, the filling yarns float and are visible on the surface of fabric. Examples: cotton sateen, and damask. In a satin weave, the warp yarn floats over four or more weft yarns and passes under only one. Adjacent warp yarns have their floats arranged



Basics of fabric structure

151

as randomly as possible, so no twill line is generated, as seen clearly in Figure 11.6

Figure 11.6 Satin weave

•• Satin: Used for ribbons, trimmings, dresses, linings, etc. and originally was an all silk fabric with a fine rich glossy surface formed in a warp satin weave. The warp is much finer and more closely set than the weft, and the latter which only shows on the underside is frequently composed of cotton. Double faced satins are made on the reversible warp backed principle, with one side differently colour from the other. •• Sateen: A cotton fabric is made in five thread weft face sateen, and woven like cotton. It is sold in bleached, mercerized or printed condition. •• Charmeuse: It is a light weight fabric woven with a satin weave, where the warp threads cross over three or more of the backing (weft) threads. The front side of the fabric has a satin finish-lustrous and reflective-whereas the back has a dull finish.

11.5

Leno weave

A leno weave is a locking type weave in which two or more warp yarns cross over each other and interlace with one or more filling yarns. It is used primarily to prevent shifting of yarns in open fabrics.

Figure 11.7 Leno weave

152

Handbook on Fabric Manufacture

In leno or gauze weave pairs of warps are twisted over each other with each passing of filling yarn. The leno weave is the modern descendant of a technique called twining that was used thousands of years ago for making fabrics. In leno-weave fabrics, the warp yarns are paired. A special attachment, the doup or leno attachment, crosses or laps the paired warp yarns over each other, while the filling passes through the opening between the two warp yarns. Leno-weave fabrics are made in Open, gauzelike constructions. They are normally used in Thermal Blankets, curtains. Mock Leno: A mock leno weave is exactly what the name implies. It is an open type weave that resembles a leno and is accomplished by a system of interlacing that draws a group of yarns together and leaves a space between the groups. The warp yarns do not actually cross each other as in a true leno and, therefore, no special attachments are required for the loom.

11.6

Honey comb weaves

Name of weave used in towelling and occasionally for cotton or wool suiting. Marked ridges and hollows suggest surface of a honeycomb. This weave is desirable in towelling because it exposes more surfaces for absorption than a plain weave.

Figure 11.8 Honeycomb weaves

11.7

Huck a back weaves

Huck a back weaves are also used for absorbent fabrics like towels. A heavy, serviceable towelling made with slackly twisted filling yarns to aid absorption.



11.7.1

Basics of fabric structure

153

Waffle weave

Waffle weaves are used for dishtowels. Waffle weave isn’t a separate structure in its own, rather it’s all in the treadling. Here is the draft of a typical waffle weave: The threading here is the traditional point twill. Waffle weave are not only on point twill threading’s, but also on Rose path and broken twill threading, as well as Huck, Monk’s Belt, and Overshot. The tie-up involves tying two treadles for plain weave, and tying the rest to lift (or sink) three shafts or one. This creates the floats, which can be seen in the close up view of fabric. The treadling is tromp as writ, which simply means treadling in the same pattern as the threading draft, that means treadling one through four and reverse. A combination of warp and weft floats create the “waffles.”

Figure 11.9 Huck a back

Figure 11.10 Waffle weave

154

11.8

Handbook on Fabric Manufacture

Crepe weaves

Crepe is a general term covering many kinds of crinkled or uneven surfaced materials. Crepe effect is brought by using hard twisted yarns or by using the right and left hand twist of warp or filling yarns. Uses of crepes are seen in kimonos, smocks, women’s and children’s dresses, curtains, needlework. Crepe effects are also produced by various other methods, not only by weave. They include producing permanently creped in grooves lengthwise by engraved rollers with heat, pressure and chemicals, Plisse a light weight thin cotton fabric with puckered stripes or all over blistery effect produced by chemicals where wax deposited on the cloth in stripes, dipped in alkali, the uncovered portions shrink, and when the wax is removed puckered stripes result. Wool crepe or Crepon is rather wiry fabric; surface effect is got due to treatment of yarns (difference in the degree of twist, or left and right hand twist in same fabric) or having some warp yarns slacker than others. • Crepe-back satin. Fabric woven in the gum with a satin face and back of tightly twisted yarns, alternating right and left hand twist, which makes a dull, crispy surface when degummed. • Creped or craped. Hard twisted yarns in right and left twist, warp or filling, or both which kink up when released from the loom. Examples – georgette, Japanese crepe.

Figure 11.11 Crepe weave



Basics of fabric structure

155

• Crepe de Chine. Crepe fabric woven in the gum of tightly twisted yarns having right and left hand twist. Crepiness appears after degumming. Heavy Crepe de Chine is very durable.

11.9

Dobby fabrics

Dobby is a woven fabric produced on the dobby loom, characterised by small geometric patterns and extra texture in the cloth. The warp and weft threads may be the same colour or different. Satin threads are particularly effective in this kind of weave as their texture will highlight the pattern.

11.10

Jacquard fabrics

Jacquard is a system of weaving that utilizes a highly versatile pattern mechanism to permit the production of large, intricate designs. The weave pattern is achieved by a series of punched cards. Each card perforation controls the action of one warp thread for the passage of one pick. The machine may carry a large number of cards, depending upon the design, because there is a separate card for each pick in the pattern. Jacquard patterns, when carefully analysed, may be seen to contain combinations of plain, twill, and satin weaves, even in the same crosswise yarn. Many decorative fabrics are made by the jacquard technique. Yarns woven into unlimited designs, often intricate, multi-colour effect. Expensive, but the design do not fade or wear out. Durability depends on the fibre used. The Jacquard loom was invented by Joseph Marie Jacquard. In Jacquard fabrics Warp is individually controlled with each pick passage creating intricate designs. Jacquard weaving is used for tapestry, brocade, Damask, brocatelle, figured necktie and dress fabrics, and some floor coverings.

11.10.1

Types of Jacquard fabric

•• Brocade: Originally a heavy rich silk fibre ornaments with raised figures formed by extra threads or by embroidery. Mostly used for upholstery fabrics and draperies. •• Damask: Fabric with a weft sateen figures on a warp satin, twist or plain grained, made of silk, cotton, rayon and linen yarns. Damasks are reversible. Cotton and linen damasks are made either with four yarn float or a seven yarn float in the satin weave. The Longer floats are more lustrous, but the shorter floats are more durable.

156

Handbook on Fabric Manufacture

11.11

Pile fabrics

Extra sets of warps or fillings are woven over ground yarns of plain or twill weave to form loops. Pile fabrics have been defined as fabrics(s) with cut or uncut loops which stand up densely on the surface Pile fabrics may be created by weaving or through other construction techniques, such as tufting, knitting, or stitch through. To create the loops that appears on the surface of woven pile fabrics, the weaving process. Piled fabric are classified as Uncut Pile and Cut Pile Fabric.

11.11.1

Uncut pile

• Loops are possible on both sides of fabric. • Soft and absorbent, relatively inexpensive. • Can snag if loops are caught. Generally they are plain or twill weaves with a third dimension – ­additional warp yarn or filling yarn is introduced into the basic structure and forms a loop at regular intervals.

11.11.2 • • • • •

Cut pile

Soft and warm, resilient, absorbent. May have a nap that must be matched. May be expensive and need professional cleaning. Method of construction. Similar to uncut pile, but loops have been cut

11.11.3

Different types of cut pile fabric

•• Corduroy: Corded velveteen structures in which a weft pile forms longitudinal lines or chords, strong heavy clothes being used for trouser-rings, smoking jackets and lighter fabrics for dress materials. •• Velvet: A cut warp pile fabric with a short, soft, dense pile. •• Velveteen: A short heavily wefted cotton fabric uniformly covered with a short dense pile of fibres which formed after the cloth has been woven by cutting certain picks of weft that float somewhat loosely on the surface.



11.12

Basics of fabric structure

157

Double cloth

Cloths woven with two sets of warp and one filling, one warp and two fillings, two fillings and two warps or with a fifth set of binding yarns to unite the two cloths. Example: double-faced coatings, ribbons and Jacquard blankets. Both sides may be alike or show a pattern reversed in colour. Weave – twill, satin, Jacquard, combined in various ways with various finishes.

12 Drawing-in

12.1

Purpose of drawing-in

Drawing-in is the process of threading warp ends through the eyes of the drop pins of warp stop motion, the eyes of the heddles and the dents of the reed in weaving. The activity of drawing-in may be manual, semi-automatic or fully automatic. The activities involve drawing-in, reaching, entering and tying. Reaching is making the yarns straight by using a hook and pushing through the eyes of drop wires, healds and reed so that they can be pulled out. Drawing-in and reaching are two operations complementary to each other. Entering is the process of threading each warp yarn on a loom beam through a separate drop wire, heddle, and reed space in preparation for weaving. This process may be done by hand or by a semiautomatic machine. Tying is the operation of pulling the warp sheet and rolling it on the fabric roll. When the same weave without any change in number of ends is to be continued on the loom, there is no need of separate drawing-in, reaching, entering operations, whereas only dressing the warp and knotting end to end using a knotter is sufficient. The purpose of drawing-in is to prepare the weaver’s beam for the purpose of weaving fabrics as per design on the loom and considering the make of the loom by drawing the ends through healds and reed as per the design plan.

12.1.1

What drawing-in should do?

a. Understanding the design and selecting the number of heald frame and the reed of required quality. b. Understanding the loom for which the beam is being prepared and getting the required heald wires, heald frames and drop pins. c. Ensuring required number of heald wires and drop pins are collected considering the number of ends in the beam and additional ends for selvedge. d. Set making, i.e. selecting required heald shaft and heald wires ,cleaning it and fixing it on to drawing-in frame. e. Dressing, i.e. drawing the sheet of ends from the beam, dressing it and fixing it on to the drawing-in frame.



Drawing-in

159

f. Drawing, i.e. drawing ends from the weaver’s beam through drop pins, heald eyes of different harnesses g. Denting the reed i.e. drawing the drawn ends through the dents of reed in the order that is determined by the design of the fabric. h. Tying the group of ends in a knot after denting in the reed.

12.1.2

What drawing-in should not do?

a. Cross drawing should not be done while drawing the ends. b. The heald eyes and drop pins of different make of looms should not be kept mixed. c. The heald wires and drop pins should not be dropped on floor while drawing or while doing any other work in the section. d. Drawing the ends without dressing properly leads to cross ends.

12.2

General activities in drawing-in

a. Getting the details of the beam, the design, pattern and the make of the loom on which the beam is to be gaited. Reading the design sheet and getting the required type and number of heald shafts as per loom and design from the heald stand. b. Bringing the heald wires, heald frames, drop pins, reed and cleaning them. Inserting the required cleaned heald wires into to the holder rods and counting the same. Preparing the set by fixing the healds frames on the frame. Transferring the required number of heald wires on to the heald shafts considering the design, number of heald shafts, body ends and selvedge ends. c. Getting the required drop pins from the stand, counting it and loading in the required number depending on the total ends in the beam. Setting the drop pin stand at required height and fixing the drop pin bars on it. d. Taking the warp sheet from the beam on to frame and cutting the groups of ends evenly with a knife and tying the ends of each bunch. Drawing the sheet of ends from the beam, dressing it and fixing it on to the drawing-in frame. Mounting the reed on to the drawing-in frame after checking for any defect. e. Cleaning the work area and the drawing-in stand by compressed air before starting the work. f. Transporting the required beam in a trolley from the specified location of beams.

160

Handbook on Fabric Manufacture

g. Leasing the warp ends of beam by hand (if leasing is not present) by separating by ends and inserting lease cord. h. After completing denting all ends as per design, writing the details of drawing-in, name of drawer and reacher, date and shift and transport the beam in trolley to the parking location.

12.3

Knowledge required for drawing-in

To handling the drawing-in operations should have knowledge of the following: a. Design, draft and pattern. b. Number of heald shafts and its effect on weaving performance. c. Types of heald wires used on different models of looms. d. Types of reed. e. Reed count. f. Drawing and reaching. g. Different types of drop pins and their suitability. h. Importance of dressing before drawing-in or knotting.

12.4

Control points and check points

It is essential for a supervisor to have clarity on the points to be controlled in drawing-in to achieve the quality and targeted production and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare their own “Control Points and Check Points” and display them in the work area so that the people can refer and follow.

12.4.1

Control points

a. Selecting suitable heald eye considering the count and material of yarn. b. Selecting suitable reed count for the design, pattern and the material of the fabric. c. Deciding the number of heald shafts considering the fabric design.

12.4.2

Check points

Material related a. The details written on beam card like the material, count and number of ends in beam.



Drawing-in

161

b. Matching of coloured yarn to the pattern and design given. c. Ensuring that there are no cross ends in the beam brought for drawing. Machine related a. The condition of the frame used for drawing-in. b. Condition of heald frames. c. The type and condition of heald wires brought and the actual requirement. d. The suitability of drop pins brought for the loom to be gaited. e. The condition of the reed. Setting related a. The pattern given and the drafting plan. b. The type of heald wires for the type of loom to be gaited. c. Suitability of reed count for the design to be produced. d. The type of reed for the material to be woven and the loom to be gaited. e. The suitability of drop pins for the type of loom. Performance related a. Number of ends drawn by a drawer (or a pair of drawer and reacher) for given time. b. Time taken to complete a beam against the expected time. Documentation related a. The beam number, design number, total ends in the beam of the beams gaited. b. The names of the beam drawer and reacher against the beam number they gaited. c. Details entered in the beam card. Work practice related a. Whether the house keeping in drawing area is good? b. Whether the reeds are cleaned before starting the work? c. Whether the alignment of shafts and beams are verified before starting the drawing work? d. Whether the healds were counted before putting on the shaft? e. Whether the wastes collected are properly put in the bin provided?

162

Handbook on Fabric Manufacture

f. Whether the knots are put properly after completing denting? Log book related a. The beam numbers planned for drawing and actual beams completed drawing-in. b. Availability of reed for the drawing-in to be done. c. Availability of heald wires and drop pins for the beams to be drawn. Management information system related a. Beam number drawn. b. Date and time of completion of drawing-in. c. Men employed for that beam. General a. Likely beam falls in the shift and in next shift. b. The looms needing only knotting and the looms needing gaiting. c. Whether the beams are drawn and kept ready for the looms to be gaited.

12.5

Normal problems in drawing-in

a. Cross ends while drawing: Cross ends are due to improper alignment of yarns on the weavers beam and slipping of yarns while drawing in. A good lighting facility is essential so that the drawer and reacher can see the ends clearly before lifting them and hooking. b. Mix up of heald wires of different types: The heald wires are different as per the material and make of the loom. Same heald wire cannot be used on all looms. Hence while a beam is runout and the heald frames are removed, care should be taken to collect all the heald wires, tie them properly, label them and then keep in the stand at designated place. If the heald wires get mixed, separate people have to be engaged to segregate them which is time consuming, very costly and unwanted job. c. Mix up of drop pins of different types: The drop pins are designed as per the type of warp stop motion and the make of the loom. Same drop pin cannot be used on all looms. Hence while a beam is runout and the drop pins are removed, care should be taken to collect all the drop pins, wire them properly, label them and then keep in the stand at designated place. If the drop pins get mixed, separate people have to be engaged to segregate them which is time consuming, very costly and unwanted job.



Drawing-in

12.6

163

Dos and don’ts

Understand clearly what are supposed to be done without fail and what should not be done at any cost. Some examples are given in below.

12.6.1 Dos a. Separate the type of heald wires like ‘J’, ‘O’ or ‘C’ type removed from heald shafts. b. Select only required type of reed considering the loom, for example profile reed for air jet looms. c. Get clarified before starting the drawing-in if denting or drawing is not clear in design sheet. d. Refer to the production programme, the beam running out status at the loom shed and decide on the beams to be taken for drawing-in sequence. e. Decide on whether to go for manual drawing-in or for automatic drawing-in depending on the quality and the looms being planned. f. Clean the work area and the drawing-in stand by compressed air before starting the work. g. Count and insert the required cleaned heald wires into to the holder rods. h. Transfer the required number of heald wires on to the heald shafts considering the design, number of heald shafts, body ends and selvedge ends. i. Spread the heald wires evenly to check free movement. j. Dress the ends properly and minimize crossing ends. k. Start and run the automatic drawing-in machine slowly to start with. l. Keep the waste in designated collection crate. m. Leave extra ends properly. n. Tie the bunch of selvedge ends in a knot on either sides into separate bunches. o. Keep the heald wires neatly and orderly. p. Start drawing from specified distance of heald frame and reed as per requirement of the type of the loom. q. Make entry of the details of beam number, design number, count, number of ends, date of receipt of beam, date of drawing-in and the team engaged for drawing-in the production register. r. Inform supervisor about the completion of the drawing-in and denting in.

164

Handbook on Fabric Manufacture

12.6.2 Don’ts a. Do not mix or throw heald wires in a haphazard way. b. Do not select flat reed for air jet looms. c. Do not assume and draw ends incorrectly if design sheet is not properly understood. d. Do not start drawing-in without properly dressing the ends. e. Do not throw waste on the floor. f. Do not use a reed for drawing which is not properly cleaned. g. Do not do the work of drawing-in poor light. h. Do not keep the warp sheet loose with less tension on the dressing frame, especially for automatic drawing. i. Do not directly run an automatic drawing-in machine at high speed without checking that drawing operation is correctly happening.

12.7

Responsibilities of supervisor in drawing-in

a. Understanding the design requirements, colour combinations and allotting competent persons for drawing-in. b. Understanding the beam fall on looms and deciding the priority to draw the beams. c. Ensuring that no loom is detained for want of drawn beam. d. Ensuring that there is no mix up of heald wires, drop pins, etc. e. Ensuring that the reeds are kept in the reed stand at the specified slots as decided and marked. f. Ensuring that drawing is done under sufficient light. g. Ensuring that the reeds, heald wires, drop pins are of required quality for the beam being drawn. h. Ensuring that the heald wires received from weaving are sorted, bundled, labelled and kept in storage place. i. Ensuring that the drop pins received are sorted, bundled, labelled and kept in storage place. j. Maintaining good housekeeping of drawing-in section all the time. k. Updating the beam card after completing the drawing-in operation. l. Maintaining discipline in the work area. m. Ensuring that all materials and records are kept in their respective place.



Drawing-in

165

n. Getting the wastes collected from each machine and putting in designated places and disposing after documenting.

12.8

Authorities of supervisor in drawing-in

a. Rejecting a beam for taking for drawing if found the ends are sticky. b. Refusing a beam if the beam card does not have all information as specified. c. Authorised to stop partially drawn beam and demanding for redrawing if mistake is found in drawing-in. d. Questioning the drawer and reacher in case of poor quality of drawing-in or slow in completing the activities. e. Sending memo to HRD in case of serious lapse in discipline by any of the employee working under him. f. Allotting or changing jobs to workers considering their skills and the requirements of the department. g. Recommending leave and/or permission to the subordinates in the section.

12.9

Some hints for better performance

a. Keep the heald wires and drop pins segregated as per their quality, make sets, put a tag and then store in the specified area. b. See that the reeds are cleaned well and there is no rust or damaged wires. c. Always keep the reeds covered with a paper to prevent getting rusted due to moisture. d. Provide sufficient light so that there shall be no mistake in drawing the ends.

12.10

Applicable formulae

Reed count = number of dents in 2 inches.

13 Weaving

13.1

Definitions and functions

Loom: A machine for weaving fabric by interlacing a series of vertical, parallel threads (the warp) with a series of horizontal, parallel threads (the filling or weft). The warp yarns from a beam pass through the heddles and reed, and the filling is shot through the ‘shed’ of warp threads by means of a shuttle or other device and is settled in place by the reed and lay. The woven fabric is then wound on a cloth beam. • The primary distinction between different types of looms is the manner of filling insertion. The principal elements of any type of loom are the shedding, picking and beating-up devices. • In shedding, a path is formed for the filling by raising some warp threads while others are left down. Picking consists essentially of projecting the filling yarn from one side of the loom to the other. • Beating-up forces the pick that has just been left in the shed, up to the fell of the fabric. This is accomplished by the reed, which is brought forward with some force by the lay.

Figure 13.1 Basic structure of a loom

Let-off motion: A device for controlling the delivery and tension of the warp during weaving. If let-off is not uniform, the fabric shall be uneven with variations in pick density and firmness.



Weaving

167

Shedding: A process of raising and lowering of warp yarns by harnesses to make an opening for the filling (weft) yarn to pass through. The raised and lowered form of warp yarns is called shed. Hence, shedding is the operation of forming a shed in weaving. Different mechanisms are used for shedding. They may be grouped as tappet mechanism, Dobby mechanism and Jacquard mechanisms. Picking: The operation of passing the filling through the warp shed during weaving. It may be done by hand or by using devices like shuttle, gripper, rapier, air jet or water jet. Heddle (also referred as healds): A cord, round steel wire or thin flat steel strip with a loop or eye near the centre through which one or more warp threads pass on the loom so that the thread movement may be controlled in weaving. The heddles are held at both ends by the harness frame. They control the weave pattern and shed as the harnesses are raised and lowered during weaving. Heald shaft/harness: A frame holding the heddles in position in the loom during weaving. It is usually more than one. Shuttle: This is a vehicle for weft and passes through the divided warp for the interlacement of the warp and weft. It has tapered ends on both the sides and a place to hold the weft yarn package in the centre. The yarn package in the form of pirn is kept inside the shuttle from which the yarn is released and inserted in the fabric as weft. Normally, shuttles are made of wood. Shuttle box: Compartment of each end of the sley of a shuttle loom used to retain the shuttle between picking motion. Picker: It is a piece of leather, plastic or metal placed in grooves or on a spindle inside a shuttle box which pushes the shuttle with force to move to the other end of the fabric across the width. Beams: A cylindrical body with end flanges on which a multiple of warp ends is wound in such way to permit the removal of these yarns as a warp sheet. Front rest: It is a fixed roller placed in front of the loom above the cloth beam and act as a guide for the cloth to wind on to the cloth beam. Lease rods: The division of warp yarn into one & one, two & two and so on is termed as lease. The two rods passed between the two successive divisions of warp yarns are called lease rods. Sley: It is the portion of loom that carries the reed and oscillates between the harness and the fell of the cloth.

168

Handbook on Fabric Manufacture

Reed: A comb-like wire or device used to separate yarns on a loom and to beat up the filling during weaving. Treadle: The treadle is a paddle or lever under a loom with which a thread is connected by means of cords. The treadle operates the heald shaft to move up and down to form the shed. Temple: Roller device on a loom that hold the cloth at a proper width to prevent it from being drawn in too much by the filling. Beating up: The last operation of the loom in weaving in which the last pick inserted in the fabric is ‘beat’ into position against the preceding picks. Basic mechanisms The basic mechanism in any type of loom can be classified as mentioned below: Primary motions: 1. Shedding: The Shedding opens the warp sheet into layers to facilitate passage of weft. 2. Picking: The Picking motion propels the weft from one end of the loom to the other. 3. Beat-up: The beating motion lays the previously laid weft to the fell of the cloth. Secondary motions: 1. Take up motion: Take up motion is an arrangement to wind the cloth on to the cloth roller. The speed of take up regulates the pick density. 2. Let-off motion: The Let-off motion is an arrangement to let the warp from the weaver’s beam at uniform rate thus maintaining the appropriate warp tension throughout the weaving process. Auxiliary motions: 1. Warp stop motion: The warp stop motion stops the loom in the event of warp breakage. 2. Weft stop motion: The weft stop motion stops the loom in the event of weft breakage or exhaustion of yarn in the weft package.

13.2

Methods of shedding

13.2.1

Tappet shedding

A tappet having a rotary motion depresses a follower and a lever, known respectively as the anti-friction bowl and the treadle arrangement, by means of



Weaving

169

which the heald shaft is operated. A tappet is a cam having some dwell period which controls the up/down movement of heald shafts and the time of opening of the shed. The bulkiness of its mechanical movement limits the loom to control up to 8 shafts. The tappet shedding is the simplest and least versatile shedding motion. The design is restricted to plain weave, simple twill and simple sateen or satin weave, simple honey comb and huck-a-back weaves. Any design more than 8 shafts requires dobby loom. The tappets can be of negative type or positive type. In negative tappet, the treadle levers are pressed by the tappet, but do not guide it back to move up whereas in the positive tappet, the bowl moves inside the groves of the tappet and is positively guided. Negative tappet shedding mechanism (Figure 13.2): A pair of tappets A and B is fixed to the bottom shaft C at 180 degrees to each other. Two treadle levers D and E are connected to the loom back-rail by a bracket F. The bracket acts as a fulcrum for the levers. The two treadles have teeth to carry the lamb rods G and H, respectively. Two heald shafts J and K are connected to the lamb rods. A top reversing roller shaft Q carries two rollers of different diameters. The roller of small diameter N is connected to leather strap L to which the front heald shaft J is connected. The roller P of large diameter is connected to leather strap M to which the back heald shaft K is connected. The tappets A and B touch the anti-friction bowls or followers R and S, respectively, which are fixed to the treadle levers.

Figure 13.2 Negative tappet shedding mechanism

170

Handbook on Fabric Manufacture

The heald shafts have heald eyes T and U through which the warp threads pass. X is the warp sheet and Y is the cloth. The odd ends are passed through one heald shaft while the even ends are passed through the other heald shaft. As the tappets revolve, they press the treadles that in turn make the heald frames move up and down, thus forming the shed to facilitate insertion of weft. A - Tappet shaft B - Tappet C - Track D - Bowl E - Tappet lever F - Fulcrum G - Link rods H - Fulcrum I - Heald wire J - Heald shaft link K - Heald shaft

Figure 13.3 Positive tappet shedding mechanism

Positive tappet shedding mechanism: In this type of shedding, the heald shaft is raised and lowered by the tappet (Ref Figure 13.3). The tappet shaft A carries tappet B that has a groove C or track in which a bowl D is placed. The bowl is connected in turn to a tappet lever E, link rods G, links J and a heald shaft K. Each tappet is separately connected to a heald shaft through link rods and tappet lever. F and H are fulcrums for tappet lever and links G, respectively. When the tappet is rotated, the bowl is also rotated. According to the shape of the groove, the bowl is moved up or down or remains still. If the bowl is moved up, the tappet lever moves to the right through the links G and J and the heald shaft is lowered. If the bowl is moved down, the tappet lever moves to the left and the heald shaft is raised. Since the heald shaft is raised and lowered by means of the mechanism, this tappet shedding is known as positive tappet shedding mechanism. When the bowl stands still, the heald shaft is in the ‘dwell’ stage. The main advantages of tappet shedding is that It is robust, simple and cheap, It is capable of lifting a heavy weight with less wear and tear than other shedding mechanisms. It can move heald shafts at great speeds, puts less strain upon the warp, consumes less power, gives greater output and requires less maintenance. It has some disadvantages also. If the weave is changed, it will be necessary to change the tappet and the change gear wheel in the counter shaft arrangement. So work involved in changing the weave is



Weaving

171

more. The capacity of a tappet to produce a pattern/weave is very much limited. A maximum of 8 or 10 tappets only can be used.

13.2.2

Dobby shedding

Dobby is a compact, electronically or mechanically guided shedding motion. Dobbies normally are capable of having up to 28 shafts. Dobby shedding is more complex and versatile shedding motion. A dobby loom, as it can have up to 28 shafts, a much greater weave repeat is possible compared to tappet shedding. Design may be woven with two or more basic weaves and their variation. Such fabrics may be referred as dobby cloths or dobby weave. Fabrics usually show geometric designs when pattern is provided by dobby. Although it can produce more complex designs compared to tappets, the production is less.

Figure 13.4 Dobby mechanism and cord

Negative dobby shedding: In the negative shedding, the heald frames are operated by the jack and lever. The levers are connected with the knife and the knives are attached with the driving rod by means of connecting needle. A pattern is used according to the weave plan. When the teeth of chain come in contact of chain drum, then whole arrangement moves together and the spring lowers the heald frame. The lowering of the heald frame happens by spring or jack lever. When the pattern cylinder does not find peg on the pattern drum then baulk lever and jack lever bring the heald frame in downward direction, and the lowering of the heald frame is occurred by means of spring tension. A manual dobby uses a chain of bars or lags each of which has pegs inserted to select the shafts to be moved. A computer-assisted dobby uses a set of solenoids or other electric devices to select the shafts. Activation of these solenoids is under the control of a computer program. In either case, the selected shafts are raised or lowered by either leg power on a dobby pedal or electric or other power sources. Positive dobby shedding: In this type of shed, both lifting and lowering of the heald frame is possible. Lifting is by means of jack and lever, and

172

Handbook on Fabric Manufacture

lowering is by means of spring under tension. It is a combination of three cylinders, jack lever, spring and a shaft. Between the three cylinders, one shaft is fulcrum in one side. The upper cylinder moves in the anti-clockwise direction and lower cylinder moves in the clock wise direction. The main cylinder gets motion from the shaft when it finds peg or pattern plan. The cylinder is attached with the upper half toothed disc and lifts the heald frame up, and when the pattern cylinder does not find peg then the main cylinder is attached with the lower half toothed disc and the spring retains the heald frame in the downward direction.

13.2.3

Jacquard shedding

Jacquard shedding is needed for large repeats of designs, which is unlimited. This shedding motion has no shafts; instead, a harness consisting of number of cords as many as the ends in the warp sheet connects each end individually to the jacquard machine. Each warp could weave independently of all others. This is complex but most versatile shedding motion. A very large repeat is possible as each warp yarn is individually controlled. Jacquard shedding mechanisms are capable of producing large and intricate weave designs that are beyond the scope of dobby shedding mechanisms. Many specialized types of jacquard machine have been developed for weaving particular kinds of fabric, such as terry towels, damasks and carpets.

Figure 13.5 Jacquard mechanism and punched cards



Weaving

173

Jacquard consists of upright hooks and horizontal needles. Needle board is a perforated board through which the needles pass. At the back of each needle, a small fine brush spring or still wire is placed. Springs are held in position in the spring box. The wires of hooks are doubled at the base. For shedding, punched card is used that is made according to design. The cards are stitched into a pattern chain, which is placed on pattern cylinder. Card holes indicates warp up of the design. The knives from the griffe (which are all fastened together) are moved up and down from the crank shaft of the loom. When the griffe begins to move upward, the cards of the perforated cylinder is pressed against the needles. It there is hole in the card, the needle directly opposite the hole will pass through it and in to the perforation of the cylinder and the knife will take the hook to which this needle is connected and forms the top line of shed. If the card is blank opposite to any needle, it will pass back the hook and as the knife lifts, the hook is left down. Now electronic jacquards are available that are controlled by computers and there is no need for preparing laborious punching cards and pattern chains. With punching card system, each weft insertion needs one punched card, and hence the number of cards in a large design used to be several thousands and several days were required to develop one design. With electronic system, a design can be developed and sample produced within 20 to 30 minutes. The speed of a jacquard loom is much less compared to a tappet loom or a dobby loom. Differences between Jacquard shedding, Dobby shedding and tappet shedding: Jacquard shedding

Dobby shedding

Tappet shedding

Most complex mechanism.

Quite complex mechanism.

Simple mechanism.

Installation cost is high.

Installation cost is medium.

Installation cost is low.

2 to 1000 yarns can be controlled collectively.

2 to 36 yarns can be controlled collectively.

2 to 8 yarns can be controlled collectively.

Jacquard is placed generally above the loom.

Dobby is placed generally above the loom.

Tappet is placed generally below the loom.

It can produce any shape of design.

It can produce square and rectangular or geometrical design.

In can produce basic design.

Harness cord used.

Heald shaft used.

Heald shaft used.

Less production.

Less production than tappet but more than jacquard.

Production is more than dobby shedding.

174

Handbook on Fabric Manufacture

13.3

Types of shed

In shedding, there are typically 2 types, namely, open shed and closed shed. There are two types of open shed, namely, fully-open shed and semi-open shed. There are two types in closed shed also. They are centre-closed shed and bottom-closed shed

13.3.1

Open shed

The shed is always in the open position in this type of shed Fully-open shed: In this type of shed, the warp threads form two stationary lines, one at the top and the other at the bottom. After inserting a pick, changes are made by carrying threads from one fixed line to the other, so some threads are lowered from the top line and some threads are raised from the bottom line. During this change, the raising and lowering of threads occur simultaneously. Therefore the shed is formed in a minimum period of time. As the falling threads help the rising threads to move, strain upon the warp yarn is low. Figure 13.6 shows a fully-open shed. In the figure, A and B are the stationary bottom and top lines respectively. The arrows C and D show the movements of the falling and rising threads respectively. Full lines show that the shed is always in an open position only. So this shed is known as fully-open shed. C

D

B A

A - Bottom line of warp B - Top line of warp C - Movement of falling threads D - Movement of rising threads

Figure 13.6 Fully-open shed

The Merits of this type of shed are as follows: 1. Rising threads help to move lowering threads. 2. Strain upon the warp is low, so it requires a minimum period of time to form a shed. 3. The loom can run at a high speed. 4. Power consumption is low. 5. Wear and tear of the loom parts is low. The Demerits are as follows: 1. This type of shedding is troublesome to weavers because the two fixed lines make it more difficult to repair broken ends. Therefore, a levelling mechanism is added to all looms using this type of shedding



Weaving

175

mechanism. While repairing broken ends, this levelling mechanism is brought in to operation. 2. As the shed is always open, breakages may results especially when the yarn is weak. 3. When many heald shafts are used, the strain on the warp yarns in the back heald shafts is increased and hence warp breakages may occur. This type of shed is used in plain loom for producing twill and satin weaves and in double-lift dobby and in double-lift jacquards. Semi-open shed: This is formed under both closed and open principles. In this shed, a stationary bottom line is retained. The top line is a movable one. After inserting a pick, the top line moves towards the bottom line. When the threads are moving down, some of the threads which are to form once again at the top line are arrested midway and are then carried to the top line. The remaining threads move down. Similarly, the threads which are to be at the top line also move up and are carried to the top line. Figure 13.7 shows a semi-open shed. In this figure, A is the bottom stationary line. B is the top line. Arrow D shows the movement of rising threads from the bottom to the top line. Arrow E shows the movement of rising threads from the bottom to the top line. Arrow F shows the movement of the arrested threads at the midway position C. From the midpoint C, these threads are carried to the top line. The full lines indicate the positions of shed lines after inserting a pick. They are in a semi-open state. So this type of shed is known as semi-open shed. B E C

F

D A

A - Bottom line of war p B - Top line of war p C - Point where some of the downward movement of threads is arrested D - Movement of rising threads E - Movement of falling threads F - Movement of arrested threads

Figure 13.7 Semi open shed

Many double-lift dobbies and double-lift jacquards form semi-open sheds. The merits of semi open shed are as follows: • In a semi-open shed, the strain upon the warp is low. • It requires minimum time to form a shed. • The loom can run at a high speed. • Power consumption is low. • Wear and tear of the loom parts is low.

176

Handbook on Fabric Manufacture

The Demerits are as follows: • This shedding is troublesome to weavers because the two fixed lines make it more difficult to repair broken ends. Therefore, a levelling mechanism is added to all the looms using this type of shedding motion. While repairing broken ends, this levelling mechanism is used. • As the shed is always open, breakages may result, especially when the yarn is weak. • When many heald shafts are used, the strain on the warp yarn at the back heald shafts is increased and hence warp breakages may occur. • In a fully-open shed, the strain on the rising and falling threads is equally distributed. But in a semi-open shed, since some of the threads are coming from the bottom line and some threads are arrested midway and again carried to the top, the strain is not equally distributed. Closed shed: This type of shed closes after insertion of every pick. Hence, all warp threads come to the same level after each pick insertion. Centre-closed shed: In this type of shed, warp threads move in an upward and downward direction from a central line. The threads which are to form the top line move upwards and the threads which are to form the bottom line move to bottom. After inserting a pick both the lines meet at the centre-line. Figure 13.8 shows a centre-closed shed. A is the centre-line. B and C are the top and bottom lines respectively. D and E are the arrows showing the movements of the rising and falling threads respectively. Centre-shed dobbies, centre-shed jacquards and handlooms form centre-closed sheds. A - Bottom line of warp B E D

A C

B - Top line of warp C - Point where some of the downward movement of threads is arrested D - Movement of rising threads E - Movement of falling threads

Figure 13.8 Centre-closed shed

Centre closed shed has advantages as a rising thread is partially balanced by a falling thread. The machine can run at high speed and the power consumption and wear and tear of the loom parts are low. However, it has some disadvantages. Since every thread is moved to form each shed, strain on the warp is more than that for the open shed. An unsteady movement of threads is caused by the warp threads being in constant motion.



Weaving

177

Bottom-closed shed: This kind of shed is formed by giving motion to only those threads that form the top line. Under these conditions, after inserting a pick, all the warp yarns come to the bottom line. Figure 13.9 shows a bottom-closed shed. A represents the bottom stationary line, B the top line and C is the arrow showing the movement of threads.

B A

C

A - Bottom stationary line of warp B - Rising and falling threads C - Arrow showing the movement of threads

Figure 13.9 Bottom closed shed

The alternate tightening and slackening of threads produces a cloth with good cover. Fine fabric, i.e., silk can be produced in this method. This method mostly is used in hand loom. Single-lift dobbies and single-lift jacquards produce bottom-closed sheds. However, it has the following demerits: a. It takes a long time to produce a shed since it is necessary to move the threads a space equal to twice the depth moved in other types of sheds. b. It is unsuitable for high loom speed. There is more chance of breakage on top warp line. c. Strain on the warp is high. There remain more stress or tension on the top warp line and less tension on bottom warp line. d. Unequal warp tension produces poor quality fabric. e. Wear and tear of the loom parts is high. f. Power consumption of the loom is high. g. By this shed type it is impossible to produce compact fabric. h. More power consumption is required in this shed type. i. It also requires more time for this type of shed.

13.4

Methods of weft insertion

The weft insertion in hand looms may be either by hand or by using a shuttle, whereas in power driven looms the weft insertion is either by using a shuttle or by number of shuttle-less methods like use of grippers, rapiers, air jet and water jet. Some weft insertion methods in practice other than the conventional shuttle looms are as follows: • Projectile technology (gripper technology) • Rapier (flexible & rigid) technology

178

Handbook on Fabric Manufacture

• Water jet technology • Air jet technology • Multi-phase weaving technology • Multi-axial weaving technology • Weaving machines & embroidery unit • Needle weaving technology for narrow fabrics & ropes • Three dimensional (3D) weaving The chart below shows the various types of looms depending on the weft insertion methods. Looms

Mulphase

Single Phase

Shule

Flat

Shule less

Warp wave (Flat)

Filling wave (Circular)

Circular

Projecle

Rapier

Rigid

Jet looms

Flexible

Air Jet

Water Jet

Figure 13.10 Different methods of weft insertion

13.4.1

Shuttle Looms 

The shuttle loom is the oldest type of weaving loom, which uses a shuttle containing a bobbin of filling yarn (pirn) that inserts weft yarn through a hole situated in the side. The shuttle is batted from both sides across the loom and during this process, it leaves a trail of the filling at the rate of about 110–225 picks per minute (ppm). Although very effective and versatile, the shuttle looms are slow and noisy. The shuttle sometimes leads to abrasion on the warp yarns and at other times causes thread breaks. The shuttle looms have number of limitations. The pirn dimensions are limited and frequently the pirns are to be replaced with fresh pirns. A separate



Weaving Filling yarn

179

Pirn

Shuttle

Figure 13.11 Weft insertion by shuttle

pirn winding process is needed to run the shuttle looms. The shuttle my fly out and result in accidents. The production rate is limited. The shed should be big enough to allow the shuttle to move freely. Although modern shuttle less looms give very high production at much lower costs, for certain type of fabrics, only shuttle looms are preferred. 13.4.1.1

Feature of shuttle less looms 

1. Shuttle less looms give much higher production compared to shuttle looms. Both speed and the width of looms are higher. 2. The entire process and cost of pirn winding is eliminated. There is no need for maintaining inventory of pirns, labour for supply of pirns to looms and collecting empty tubes, cleaning of bottom wastes and so on. 3. Strain upon the warp threads is reduced due to smaller depth of shed. This helps in going for higher speeds of loom. 4. Heavy cost of repairs and replenishment of worn out parts is reduced. 5. The physical and mental strain upon the weaver is reduced because of lesser noise. 6. A weaver can look after more looms compared to shuttle looms. 7. There is no risk of shuttle fly out owing to the absence of conventional shuttle and packing being positive. 8. Quality of the fabric gets enhanced because of a positive control over the weaving process. 9. The looms are easier to work and manipulate. 10. Efficiency of the shuttle less weaving shed is comparatively higher as there are less warp breaks and large cones are fed in weft instead of small pirns.

13.4.2

Projectile looms

A bullet-like flying part 90 mm long and weighting about 40 g, technically named as gripper projectile is used to insert the weft thread into the warp threads. Sulzer brothers, Winterthur, Switzerland, developed the projectile method of weft insertion.

180

Handbook on Fabric Manufacture

Figure 13.12 Weft insertion by projectile

The picking and the projectile units are separated from the moving sley. The sley (projectile track) carries the reed and gripper guides. The gripper projectile, made of the fine steel 90 mm long, 14 mm wide and 6 mm thickness carries the weft thread in to the warp shed. The weft is drawn directly from a large stationary cross wound package with or without accumulator. The gripper projectile is picked across the warp shed at the very high speed, the picking energy being derived from the energy stored in the metal torsion bar which is twisted at predetermined amount and released to give the projectile a high rate of acceleration. Picking always takes place from one side but several projectiles are working on conveyor chain located underneath the warp shed. During its flight through the shed the projectile runs in a rack like steel guides, so that the warp threads are touched neither by the projectile nor weft thread. Every pick is cut-off at the picking side near the selvedge after weft insertions, leaving a length about 15mm from the edge. Similar length of weft also projects from the selvedge on the receiving side. The ends of weft thread projecting on both sides of the cloth are tucked into the next shed by means of a special tucking device and woven in with next pick, thus providing firm selvedge. The reed is not reciprocated as in a shuttle loom, but rocked about its axis by a pair of cams. The reed and projectile guides are stationary during pick insertion. The sley which carries the reed and projectile guides is moved forward and backward through a saddle carrying two follower bowls, which bear against the surface of two matched cams. A sley dwell of 255 at back centre enables the projectile to travel through the warp shed without being unnecessarily reciprocated by the sley. Whenever the reed width is reduced for weaving a small width cloth from the standard reed width, the projectile receiving unit is moved inward on the telescopic shaft, to the new selvedge position, and so the projectile travel distance is reduced. Projectile looms have smaller shed opening compared to shuttle looms because of the smaller size projectile. This might result in lower warp breakage rate. It is possible to achieve weaving performances with breakage rates per square metre of cloth at 50% of the number of breaks that would occur on a conventional loom. The lower warp breakage rate in a projectile weaving machine may be due to smaller warp shed, reed with higher ratio of air to wire (70:30) and beat up line being nearer to the centre of the reed between the two baulks.



Weaving

181

A reed with higher ratio of air to wire will give a greater flexibility. Similarly, if the beat-up line is nearer to the centre of the reed oversized knots will pass more readily because of greater flexibility of the reed wires. In the conventional loom beat-up line is much nearer to the bottom baulk of the reed. This will result in building up higher tension of warp thread if a bigger knot of that particular thread could not pass through the reed dent, and finally the end will break. Smaller warp shed will reduce the warp threads tension to some extent. However, care should be taken to maintain uniform tension to ensure that the warp shed is of same depth from one end to another. Otherwise a few slack warp threads at the top shed will result in stitching and end cut by the projectile. Weft insertion rate from 900 to 1500 m/min. is possible depending up to the width of the weaving machine. The colour changing mechanism is less complicated. There is facility of inserting two picks in the same shed without the use of a dobby. In case of weft breakage, the take-up beam and heald frames can be driven in reverse by a pick finding mechanism. Two or three cloths can be woven simultaneously. There are four sizes in projectiles as explained below: Table characteristics of projectile looms D1 (steel)

D12 (steel)

D2 (steel)

K3 (composite)

Length

89.00

89.00

89.00

96.00

Width

14.30

14.30

15.80

18.00

Height

00.35

00.35

8.50

8.00

D1 is the standard steel projectile for the vast majority of commercial yarns. D12 is the same as D1 with a larger yarn clamping surface to ensure more reliable gripping ever of delicate yarns. D2 has a big cross section and large clamping surface and is used for extremely coarse yarns. K3 is the synthetic (carbon composite) projectile which was intended to economically produce very delicate fabrics.

13.4.3

Rapier (flexible and rigid) technology

Insertion of weft by rapier is a mechanically modern and refined version of the primitive method of fabric production in which the weft was secured in a slot of a stick. At present version of the gripper head which are attached to rapiers which are flexible tapes or rigid rods. Mr. John Gabler can be regarded as the father of modern rapier technology he has built a rapier device on a cotton weaving machine in 1922. 

182

Handbook on Fabric Manufacture

Rapier loom may have various types according to the weft insertion mechanism and number of pick such as insertion of double pick, insertion of single pick, two phase rapier etc. In all rapier looms, to-and-fro-movement of the rapiers is derived initially either from a linkage mechanism or from a cam. The use of linkage mechanism has the advantages of simplicity reliability and is cheap, quiet and consumes less energy than a cam mechanism but it does not provide any dwell to the rapiers. Single rapier loom can insert weft only on alternate rapier traverse. In many cases this is modified to achieve a higher rapier velocity in the early and late parts of the movement and thus maximum velocity halfway through the movement. A useful feature of rigid rapiers is that they can be simultaneously inserted in two sheds one above the other, for producing double plush and certain carpets. Filler yarn

Rigid Rapier

Filler yarn

Flexible Rapier

Figure 13.13 Weft insertion by rapier

Due to high rate of insertion, the possibility of yarn breakages rate may increase. Additionally, it is necessary to control the weft by passing it through an effective tension arrangement so that the weaving tension will be more uniform, this can also reduce weft break. The rigid rapier is driven from the centre and has a rapier head at each end. In one cycle of 360 degree the rapier inserts one pick alternately in the right hand and left hand. The picks are inserted and beaten up in opposite phase.

13.4.4

Jet looms

In jet picking, the weft yarn is inserted by means of a fluid known as jet. The fluid may be air or water. The relative velocity between the jet and the weft yarn produces a force on the weft which results in its insertion in the shed.



Weaving

183

The air jet looms are supplied with compressed air from a compressor. The water jet looms are equipped with individual injection pumps to pressurize water. Waste water is discharged into a drain. To achieve acceleration of either compressed air or pressurized water together with the leading end of the weft yarn, a nozzle is used. The mass of insertion medium to be accelerated is very small, relative to shuttle, projectile or rapier. This allows the looms to run at a very high speed. Unlike shuttle, rapier or projectile weft insertion systems, there are not many mechanically moving parts to control the insertion of weft yarns. However, technical requirements of the fluid are important. As the tractive force applied to the weft is not very high, it is needed to be prepared for insertion by a metering device. In majority of jet weaving machines, the picking system is fitted only on one side and firmly to the machine frame so that the beat-up mechanism carries only the reed and/or the air duct. 13.4.4.1

Air jet looms

Weft insertion by means of air jet has made a major breakthrough in the early 1970s and its importance is increasing further because of its ability to weave a wide range of fabrics at a very high speed weft insertion rate of about 2000 MPM. The first attempt to use a compressed air stream instead of shuttle is made by Brooks in 1914.  Air Filling yarn

Figure 13.14 Weft insertion by air jet

To insert the weft compressed air is used. It is generally not suitable for the coarser count or heavier fabric, but recently denims are being produced on air jet looms. The timing of jet activity should be controlled in such a way that the main nozzle is supplied with compressed air from the beginning of the weft insertion phase and the relay nozzles also receive compressed air. High maintenances is needed. Following are main parts of Air Jet loom for weft insertion: • Tensioner: Additive disk type tensioner is used for weft insertion which maintain proper tension in the weft yarn. • Weft break sensor: It is an electric sensor which detect any weft break in the region between weft package and accumulator and automatically stop the loom in case any weft break.

184

Handbook on Fabric Manufacture

• Accumulator: It is a device fitted between weft package and main nozzle that unwinds a predetermined length of weft from the package and store it in the form of number of coils on a cylindrical drum. This yarn is then fed in to insertion device.  • Stopper: It is an electronically controlled electromagnetic device integrated with the accumulator. Its function is releasing the yarn at start of insertion and stop it at the end of insertion.  • Balloon breaker: It is fitted just after accumulator. Its function is to separate the balloon formation so as to reduce as ballooning tension as well as minimising the tension fluctuation. It is generally used for coarser yarn. • Fixed main nozzle: Its function is to form the air jet from compressed air with the required velocity and acceleration characteristics and project it in a proper direction in to air guide channel.  • Relay nozzle or sub nozzle: Fitted in series along the sley. It creates an additional air flow in the direction of air jet so as to compensate the loss of air velocity.  • Profile reed: In air jet loom the reed is profiled so as to form a guide channel which guides the air jet as well as weft during insertion.  • Weft cutter: It is cam operated device fitted in the region between the moveable main nozzle and the reed at picking side. Its function is gripping and cutting the weft after every pick at around beat-up.  • Air guide channel: It is formed on the reed. Its function is guiding and confining the free expansion of the air jet in order to maintain the velocity over larger distance as possible.  • Weft detector: It is an optical device fitted at the end of reed at the receiving side. Its function is to check the arrival of weft at the receiving side. In case of late arrival or miss pick it senses and stops the loom.  • Stretch nozzle: It is located just beside the weft detector. It supplement the effect of enhanced stretching action on the weft by the closely spaced relay nozzle at the end of insertion so as to prevent the chance of weft recoiling due to action of stopper.  • Selvedge cutter: Located at the receiving side. It is an electronically operated mechanical device which cut the weft yarn extending between fabric and auxiliary selvedge so as to separate the auxiliary selvedge which is passed out as a waste. 13.4.4.2

Water jet looms In a water jet loom, a miniature pump is used to feed water under pressure to the nozzle. The water carries the weft from one end to another. As water is



Weaving

185

used to carry the weft, both weft and warp yarn must be insensitive to water, i.e., hydrophobic in nature. The use of water-jet looms is restricted to filament yarns of acetate, nylon, polyester and glass; yarns that are non-absorbent, and those that do not lose strength when wet. Weaving of the water absorbing materials (Hygroscopic) is not possible by the water jet loom. Thermoplastic yarns offer the advantages of severance of weft by a heated blade and the provision of a heat selvedge by fusing. In this technique, a water jet is shot under force and, with it, a weft yarn. The force of the water as it is propelled across the shed carries the yarn to the opposite side. This machine is economical in its operation. A water jet of only 0.1 centimeter is sufficient to carry a yarn across a 48-inch shed. The amount of water required for each weft yarn is less than 2.0 cubic centimetres. Water-jet machines can reach speeds of 2,000 meters of picks per minute. The water jet looms can produce superior high quality fabrics that have good appearance and feel. They are less noisy and require less space than most other types of weaving machines. They cause minimal damage to warp yarns during the weaving operation, because the air or water jets are less abrasive than moving metal parts.

Pressurized Water

Nozzle

Filling yarn

Figure 13.15 Weft insertion by water jet

Figure 13.16 Water jet loom

186

13.5

Handbook on Fabric Manufacture

Multi-phase loom

Multi-phase weaving machine is one in which several phases of the weaving cycle takes place at any instant such that several filling yarns can be inserted simultaneously. In this mechanism, more than one weaving shed is formed at a time. A multi-phase loom with magnetic shuttle features that the spiral reed blade with shuttle path is used for beating-up. The linear motor is used for wefting, the heald wheel or electromagnetically excited heald needle is used for opening, and the weft opening with off-line multi-path asynchronous weft replenishing is used. Its advantages include high efficiency, high speed and low weaving cost. The process transforms weaving into a continuous process rather than a cycle of shedding, picking, and beating up. Multi-phase loom continually inserts weft yarns from yarn carriers. Rotary beat-up devices press inserted yarn firmly against previously formed cloth. If the pattern changes, small groups of yarns are changed into a new shedding position after each new yarn carrier has passed.  The operation of multished weaving machines is based on a series of wave like motions across the weaving surface. In general, fabrics woven on these looms do not have a true 90° angle between warp and weft; the weft yarns are slightly slanted or skewed. Multished weaving is limited to special types of fabrics, but it can be expected to gain acceptance in the years ahead.  The Multi-phase can weave 190 cm width with 69 meters of fabric per hour. It can form many different sheds at different places, thereby enabling insertion of number of filling yarns, one behind the other. As many as 16–20

Figure 13.17 Multi-phase loom



Weaving

187

weft carriers insert the pre-cut weft in a continuous process instead of the intermittent process of single-shed weaving. Beating up and shedding arrangements are different. In this continuous weaving process, the number of picks per minute is doubled. However, multi-phase looms have never been extensively used in the industry.

13.6

Multi-axial weaving technology

In recent years, multi-axial fabrics have begun to find favour in the construction of composite components to provide sufficient strength in multiple directions. These fabrics consist of one or more layers of long fibres held in place by a secondary non-structural stitching thread. The main fibres can be any of the structural fibres available in any combination. The stitching thread is usually polyester due to its combination of appropriate fibre properties and cost. The main design considerations for this system are that sufficient additional fibre is supplied so the ±45° fibre is very dense, the additional fibre does not impede the base structure, and that the system be suited to existing weaving equipment. The stitching process allows a variety of fibre orientations, beyond the simple 0/90° of woven fabrics, to be combined into one fabric. The most common forms of this type of fabric are shown in the following diagrams:

Figure 13.18 Common forms of multi-axial cloth

Multi-axial machines enable reinforcement materials to be made in one single manufacturing process. These materials comprise uni-axial non-woven plies (0°, 90°, + or – 45°), which are laid one on top of the other and stitched together. These fabrics consist of one or more layers of long fibres held in place by a secondary non-structural stitching tread. The main fibres can be any of the structural fibres available in any combination. The stitching thread is usually polyester because of its combination of appropriate fibre properties (for binding the fabric together) and cost. The stitching process allows a variety of fibre orientations, beyond the simple 0/90° of woven fabrics, to be combined into one fabric. The two main

188

Handbook on Fabric Manufacture

improvements with stitched multi-axial fabrics over woven types are better mechanical properties, mainly from the fact that the fibres are always straight and non-crimped, and that more orientations of fibre are available from the increased number of layers of fabric. With the ‘weave and stitch’ method, the +45° and -45° layers can be made by weaving weft unidirectional and then sewing the fabric, on a special machine, to 45°. A warp unidirectional or a weft unidirectional can also be used unsewed to make a 0° and 90° layer If both 0° and 90° layers are present in a multi-layer stitched fabric then this can be provided by a conventional 0/90° woven fabric. Due to the fact that heavy rovings can be used to make each layer the weaving process is relatively fast, as is the subsequent stitching together of the layers via a simple stitching frame.

Figure 13.19 Forming a stitched multi layer fabric

To make a quadraxial (four-layer: +45°, 0°, 90°, -45°) fabric by this method, a weft unidirectional would be woven and skewed in one direction to make the +45° layer, and in the other to make the -45° layer. The 0° and 90° layers would appear as a single woven fabric. These three elements would then be stitched together on a stitching frame to produce the final four-axis fabric, Simultaneous stitch manufacture is carried out on special machines based on the knitting process. such as those made by Liba, Malimo, Mayer etc. Each machine varies in the precision with which the fibres are laid down, particularly with reference to keeping the fibres parallel. The two key improvements with stitched multi-axial fabrics over woven types are better mechanical properties, primarily from the fact that the fibres are always straight and non-crimped, and that more orientations of fibre are available from the increased number of layers of fabric and improved component build speed based on the fact that fabrics can be made thicker and with multiple fibre orientations so that fewer layers need to be included in the laminate sequence. A novel method and apparatus was developed by Angela Durie, Ross Griffith and Alan Tomlinson for integrally weaving a dense sheet of parallel



Weaving

189

±45° fibre on the surface of woven structures. The additional ±45° fibre has been incorporated onto a range of compound three-dimensional structures by means of a new device, which was developed for use with conventional weaving looms. The additional fibre forms a contiguous plane of ±45° fibre, while the configuration of the underlying structure remains substantially undisturbed. Three-dimensional multi-axial structures have been successfully produced using high performance fibres including carbon and glass, which require special processing considerations. These developments are based on modified lappet weaving technology. The base weave structure can be produced using conventional weaving equipment, with the additional fibre introduced using an add-on lappet device and associated driving mechanisms. The system developed allows for the interlacing of the additional bias yarns on a freely selected basis. The intermittent, selective binding of the extra yarns allows for a very high density of these yarns without detriment to the base structure at the interlacing points. In addition, this selectivity allows for all yarns to be successively incorporated into an edge if required. This system can produce quadraxial structures via a conventional loom, as distinct from those which require special additions to a triaxle loom. The device consists of a guide plate, tube guide, tube and depression plate as illustrated in Figure 13.20. The bias fibre is passed through the tube, which in turn telescopes through the tube guide. The bracket on the tube guide fits onto the guide plate. The depression plate fits around the upper end of the tube to engage the depression collar. The figure shows only one tube assembly on the guide plate; in practice, the guide plate is tightly packed with many tube assemblies.

Figure 13.20 Components of the bias device & assembled device showing only one tube

190

Handbook on Fabric Manufacture

Each tube can be selectively lowered into the upper shed of the base structure by engaging the depression collar using the depression plate (which can have a variety of profiles depending on the desired tie-in sequence). The additional yarn in the lowered tube is bound into the base structure using weft yarn. The tubes are then lifted and weaving takes place while the tubes progress laterally around the guide plate. This has the effect of moving the additional yarn across the warp. The sequences in this process are illustrated and described in more detail below:

Figure 13.21 Schematic of bias forming sequence; steps 1 to 8

• Step 1 - The reed beats up to the fell position to consolidate previously inserted weft. The tubes, tube guides and guide plate are held forward of the fell position so as to be clear of the forward motion of the reed, this is known as the rest position. This position may be held for several weaving cycles that do not involve binding of the bias reinforcement. • Step 2 - The reed is withdrawn from the fell position. The tube guides and guide plate are held in the rest position. • Step 3 - With the reed at back centre, a shed is formed from the warp yarns. A special selection of warp yarns is made to accommodate the selected tubes. The guide plate and accompanying tube guides and tubes are moved away from the rest position toward the reed and coming in close proximity to, but forward of the reed. The tubes remain above the upper shed.



Weaving

191

• Step 4 - Using the depression plate, selected tubes or all tubes, depending on the desired structural characteristics, are lowered between the upper shed warp yarns previously positioned in Step 3. • Step 5 - Weft is inserted into the shed now formed, which includes at least some bias reinforcing fibre in the lower shed position. Figure 13.22 is a photograph of the apparatus at this stage of the weaving sequence. • Step 6 - The previously lowered tubes, as in Step 4, are now raised to the neutral position where the bias reinforcing is above the upper shed position of the warp yarns. • Step 7 - The guide plate including guide tubes and tubes, is moved towards the rest position and the reed moves forward to beat the weft into the fell position. The beat-up of weft yarn may occur in the open shed, closed centre or closed bottom shed positions. • Step 8 - The guide tubes are moved around the guide plate to the next position. This position is determined by the desired binding pattern. To achieve a binding of each yarn at the edge of the bias zone of the fabric, it would be necessary for each tube to dwell for one cycle at the extremities of the guide plate.

Figure 13.22 The device in use, processing carbon fibre (Step 5)

In its most obvious application, the bias reinforcement would be incorporated across the full width of the base fabric. However, the system is also capable of confining the zone of additional fibre within these boundaries, and even allowing variable positioning of the zone during production of a particular product, a feature which may be useful for curved components. Similarly,

192

Handbook on Fabric Manufacture

the rate of binding of the additional yarns into the base structure can be altered during production, resulting in variation in the angle of the additional reinforcing, as shown in Figure 13.23, which can range from close to the weft direction through to the warp direction. Individual bias reinforcement yarns may be stopped short of the edge, while others may continue to the full extent of the zone. This would allow tapering of the bias yarns at the edges of the structure, and would be useful in optimising fibre placement for an I-beam where less ±45° fibre is required on the flanges compared to the web. This is achieved through selective tube control by altering the profile of the depression plate, or using different plates in the one design.

Figure 13.23 Angle of the bias fibre changing

Figure 13.23 is an example of the weave structure produced using bias forming device where the angle of the bias fibre changes along the sample. Each bias yarn proceeds to the edge of the bias forming zone. The plain weave of the base structure is largely undisturbed. Additional fibre has been added to customary two-dimensional orthogonal woven structures, compound or multilayer woven structures and complex three-dimensional woven structures such as I-beams and sandwich structures. The additional fibre can form a contiguous plane, while the configuration of the underlying structure remains substantially undisturbed. Triaxial fabrics: Triaxial weave has basically three sets of yarns as ± bias (± warp) and filling. They interlaced to each other at about 60˚ angle to form fabric as shown in Figure 13.24. The interlacement is similar with the traditional fabric which means one set of yarns is above and below to another and repeats through the fabric width and length. Generally, the fabric has



Weaving

(a)

(b)

193

(c)

Figure 13.24 Triaxial fabrics - loose fabric (a), tight fabric (b) and one variant of triaxial woven fabric (c)

large open areas between the interlacements. Dense fabrics can also be produced; however, it may not be woven in a very dense structure compared to the traditional fabrics. This process has mainly open reed. Triaxial fabrics have been developed basically in two variants. One is loose-weave and the other is tight weave. The open-weave triaxial fabric has certain stability and shear stiffness to ±45˚ direction compared to the biaxial fabrics and has more isotropy. The machine consists of multiple ± warp beams, filling insertion, open beat-up, rotating heddle and take up. The ± warp yarn systems are taken from rotating warp beams located above the weaving machine. After leaving the warp beams, the warp ends are separated into two layers and brought vertically into the interlacing zone. The two yarn layers move in opposite directions, i.e., the front layer to the right and the rear layer to the left. When the outmost warp end has reached the edge of the fabric, the motion of the warp layers is reversed so that the front layer moves to the left and the rear layer to the right as shown in Figure 13.25. As a result, the warp makes the bias intersecting in the fabric. Shedding is controlled by special hook heddles which are shifted after each pick so that in principle they are describing a circular motion. The pick is beaten up by two comb-like reeds which are arranged in opposite; each other in front of and behind the warp layers, penetrate into the yarn layer after each weft insertion and thus beat the pick against the fell of the cloth.

(a)

(b)

(c)

(d)

Figure 13.25 The schematic views of weaving method of triaxial woven fabrics; bias orientation (a), shedding (b), beat-up (c) and take-up (d)

194

13.7

Handbook on Fabric Manufacture

Weaving machines with embroidery unit

Germany-based Lindauer Dornier GmbH’s has introduced a new dimension for pattern on Dornier weaving machines by adding embroidery units. They are as follows: • DORNIER A1: Air jet weaving machine with embroidery unit • DORNIER P1: Rapier weaving Machine with embroidery unit The Dornier ORW (Open Reed Weave) technology allows wide diversity in pattern for clothing and decorative fabrics or specially applied reinforcements in technical textiles, which considerably extends pattern versatility for light, classic fabrics and eliminates downstream processing. The production of figures highlighted in colour in fabrics for clothing and furnishing fabrics requires a certain technical effort such as increasing the number of shafts or using Jacquard equipment for weaving Scherli effects or subsequent further processing through embroidery. By using ORW technology, it is possible to successfully integrate embroidery in the weaving process, so that weaving and embroidery can run at the same time on weaving machines. Air-jet weaving machine AWS 6/S 12 OC is integrated with an embroidery mechanism that controls a set of yarns. The embroidery yarns are guided by needles and are raised up to move out of the reed dents as the reed is open at top. While they are out of the reed, these yarns are moved laterally

Figure 13.26 Dornier air jet type AWS 6/S 12 OC with embroidery unit



Weaving

195

depending on the embroidery design, and then are lowered and entered into the reed dents. The embroidery yarns form sheds to interlace with the weft yarns according to the design. The sequence is repeated until a design repeat is formed. Besides the competition with embroidery machinery, the system could replace the weaving technique known as extra warp figuring that requires dedicated Jacquard hooks. The system also competes with the embroidery effect produced by yarn lay-in in warp knitting. While intricate design could be obtained by the system, the degree of intricacy is limited compared to that of traditional embroidery because of the limitation of the lateral movement of embroidery needles or yarns. Another limitation of the system is that the embroidery yarn size is limited to the reed dent width. 

13.8

 ulti-axis three dimensional (3D) M woven fabric

Three dimension (3D) textile structural composites are widely used in various industrial sections, such as civil and defence as they have some better specific properties compared to the basic materials such as metal and ceramics. The textile preform fabrication may be done by weaving, braiding, knitting, stitching and by using non-woven techniques, and they can be chosen generally based on the end-use requirements. The three dimensional (3D) preforms are classified according to fibre interlacement types. Multi-axis 3D woven preform is developed in the specially developed Multi-axis 3D weaving and its in-plane properties are improved by orienting the fibre in the preform.

13.8.1

3D orthogonal fabric

3D orthogonal woven preforms have three yarn sets: warp, filling and z-yarns. These sets of yarns are interlaced to form the structure wherein warp yarns are longitudinal and the others are orthogonal. Filling yarns are inserted between the warp layers and double picks are formed. The z-yarns are used for binding the other yarn sets to provide the structural integrity. The unit cell of the structure is given in Figure 13.27. A loom which has three rigid rapier insertions with dobby type shed control systems is converted to produce 3D woven preform as seen in Figure 13.28, which can also produce various sectional 3D woven preform fabrics. Specially designed weaving looms for 3D woven orthogonal woven preform are developed to make part manufacturing for structural applications as billet and conical frustum. They are shown in Figure 13.29. First loom was developed based on needle insertion principle by King in 1977 whereas second loom was developed on the rapier-tube insertion principle by Fukuta in 1974.

196

Handbook on Fabric Manufacture

(a)

(b)

Figure 13.27 Orthogonal woven unit cell; schematic (a) and 3D woven carbon fabric (b)

(a)

(b)

Figure 13.28 Traditional loom (a) and new loom (b) producing 3D orthogonal woven fabrics

(a)

(b)

Figure 13.29 weaving looms for thick part manufacturing based on needle (a) and rapier (b) principles

3D angle interlock fabrics can be fabricated by 3D weaving loom. They are considered as layer-to-layer and through-the-thickness fabrics as shown in Figure 13.30. Layer-to-layer fabric has four sets of yarns as filling, ± bias and stuffer yarns (warp). ± Bias yarns oriented at thickness direction and interlaced with several filling yarns. Bias yarns made zig-zag movement at the



Weaving

197

thickness direction of the structure and changed course in the structure to the machine direction. Through-the-thickness fabric has again four sets of fibres as ± bias, stuffer yarn (warp) and fillings. ± Bias yarns are oriented at the thickness direction of the structure. Each bias is oriented until coming to the top or bottom face of the structure. Then, the bias yarn is moved towards top or bottom faces until it comes to the edge. Bias yarns are locked by several filling yarns according to the number of layers.

(a)

(b)

Figure 13.30 Angle interlock fabrics (a) and schematic view of 3D weaving loom (b).

Another type of 3D orthogonal woven fabric, which pultruded rod is layered, was introduced by Evans in 1999. ± Bias yarns were inserted between the diagonal rows and columns for opening warp layers at a cross-section of the woven preform structure. The process includes ± bias insertion needle assembly, warp layer assembly and hook holder assembly as shown in Figure 13.31. Warp yarns are arranged in matrix array according to preform cross-section. A pair of multiple latch needle insertion systems inserts ± bias yarns at cross-section of the structure at an angle about 60˚. Loop holder fingers secure the bias loop for the next bias insertion and passes to the previous loop.

(a)

(b)

Figure 13.31 Orthogonal fabric at an angle in cross-section (a) and production loom (b)

13.8.2

Multi-axis 3D fabric

Multiaxis 3D woven fabric, method and machine based on lappet weaving principles were introduced by Ruzand and Guenot in 1994. Fabric has four

198

Handbook on Fabric Manufacture

yarn sets: ± bias, warp and filling as shown in Figure 13.32. The bias yarns run across the full width of the fabric in two opposing layers on the top and bottom surfaces of the fabric, or if required on only one surface. They are held in position using selected weft yarns interlaced with warp binding yarns on the two surfaces of the structure. The intermediate layers between the two surfaces are composed of other warp and weft yarns which may be interlaced.

(a)

(b)

(c)

Figure 13.32 Multi-axis 3D woven fabric (a), structural parts (b) and loom based on lappet weaving (c)

The basis of the technique is an extension of lappet weaving in which pairs of lappet bars are used on one or both sides of the fabric. The lappet bars are re-segmented and longer greater than the fabric width by one segment length. Each pair of lappet bars move in opposite directions with no reversal in the motion of a segment until they fully exceed the opposite fabric selvedge. When the lappet passes across the fabric width, the segment in the lappet bar is detached, its yarns are gripped between the selvedge and the guides and it is cut near the selvedge. The detached segment is then transferred to the opposite side of the fabric where it is reattached to the lappet bar and its yarn subsequently connected to the fabric selvedge. Since a rapier is used for weft insertion, the bias yarns can be consolidated into the selvedge by an appropriate selvedge-forming device employed for weaving. The bias warp supply for each lappet bar segment is independent and does not interfere with the yarns from other segments.

13.9

Needle weaving technology

Narrow looms technology was introduced by Jakob Muller, Switzerland whereas Eppa H. Ryon, patented his Needle loom in USA in 1903 for producing narrow fabrics-like ribbons and tapes. In this class of looms, a series of narrow-ware fabrics or ribbons are woven on one loom, each fabric being woven separately by a separate needle mechanism. In E. H. Ryon’s needle mechanism, the needle has a pivotal or swinging motion to carry the filling-thread over the shuttle, supplying the selvage - thread, and also an



Weaving

199

additional motion in the direction of the width of the fabric to move the pivotal support of the needle toward and away from the fabric in the operation of weaving. In a needle loom, the oscillating needle carry the filling-thread. A longitudinal reciprocating bar connected with the needle-supporting for moving the bar causes the oscillation of the needle-supporting and the movement toward and away from the fabric. The combination with the lay a bar supported on an oscillating lever connected with bar, and a needle attached to lever, of a cam-surface fast on the lay and adapted to engage and oscillate lever and the needle, and mechanism for communicating a longitudinal reciprocating motion to bar substantially. In needle mechanism, the combination with the breast beam and a shuttle-supporting arm pivotally support a spring acting on arm. A shuttle-holder supported on arm, and an extension on arm adapted to extend in the path of and be engaged by a roll or pin on the lay, of roll or pin, adapted to engage shuttle-supporting arm and move the same away from the fabric, on the forward beat of the lay. The combination with a needle having an oscillating movement and also a reciprocating transverse movement in the direction of the width of the loom, at its pivoted end, of means for communicating to needle an oscillating movement, and also a transverse movement at its pivoted end, substantially. Functions of different parts of a needle loom are as follows: • Connecting rods connects the reed arm to the weft arm and plays a very crucial role in the needle loom. • Flat healds, Steel healds, Wire healds are fitted in the frame to create a shed for precise weaving. Different sizes available as per loom models and sizes. Even healds with two eyelets for two sheds is available. • Metal link of different sizes and shapes assemble together to form a cam. In old days, cams were designed, manufactured to suit different designs and new cams were made for each new design. With the metal links and plastic locks, one can make his own flexible cam in the form or a chain also. He can even dismantle the cam or chain and reuse the links and locks to prepare new cams or chains. So these are also known as the flexible cams. • Weft needle or carrier fitted on the carrier arm carries the weft thread between the shed from one to the other end and back, hence creating a weave between the warp and the weft. Since it carries the weft thread this component is also called the carriers.

200

Handbook on Fabric Manufacture

Figure 13.33 Needle looms and weft insertion

• Weft Arms or Carrier Arms rest on the axle & bearings, which is driven with the help of the connecting rod by the reed arm, plays a significant role in the weft weaving process. Since it carries the weft needle and the weft thread to weave the tape this part is also known as the carrier arm. • The cam or chains in a loom makes the shedding lever rise and fall. Heald frames are attached to these levers which also rise and fall hence creating a shed through which the weft passes creating a weave. With reference to the cam design or chains the number of times the lever rises and falls and stays up or down with reference to picks creates a design as required. Hence levers are called shedding levers and is considered to be the pulmonary function of the machine.



Weaving

201

• Droppers are used mainly to ensure warp threads in weaving process controls the electronic stop motion and acts as a switch. If one or many warps break the dropper drops and acts as a switch to stop the machine controlled through various electronic devices. • Reed arms fitted on a shaft which creates an oscillation motion. The front reed is fitted on this arm which aligns the weft pick on completion of one oscillation. Perpendicular and precise manufacturing in accordance with requisite dimensions is the key to this product. • Heald frame supports assembled to form a heald frame. These supports are manufactured to utmost perfection in terms of dimensions and raw materials. Since there is constant movement within the slides there is a lot of frictional heat and resistance on this component. • Gears and pulleys are the integral part of engineering motion mechanics. Manufactured on state of art CNC hobbing or milling machines gears have very precise spam measurement resulting in very controlled and precise movements of the shafts and rollers. • Weft feeders control the throw of weft thread while weaving. It ensures very smooth finish and even surface to avoid yarn breakage. • Reed has a dual purpose in weaving. It acts as a separator of warp yarn (threads) and also is used to align the weft yarn.

13.10

Measuring weaving loom shed performance

Weaving performance is normally measured as the efficiency, which is expressed as a percent of picks inserted to the picks that should have been inserted as per the speed of the loom. However in this system there are some shortcomings. For a given yarn and count, if the ends per inch and picks per inch are lesser, it shall be easy to weave and one can get a higher efficiency. If the total ends are more in a loom, it shall have more stoppages due to warp breaks considering the same quality of yarn and weaving preparation. New measures were suggested by the author in his article ‘towards scientific evaluation of loom shed performance’ in Journal of Textile Association published in Sept 1979. The concepts are as follows: Initially, a system was suggested considering the number of interlacements done in a given time as a measure of loom shed performance and was called as ‘P’ value. As the counts become finer, it shall be easy to have more interlacements, and hence a second measure was developed by dividing P value with product of square roots of warp count and weft count, or multiplying the P value with product of Tex of warp and weft. This measure was termed as ‘Q’ value.

202

Handbook on Fabric Manufacture

As calculating both ‘P’ value and ‘Q’ value takes more time, an easy measure was developed, which is obtained by multiplying total square meters of fabrics produced with cover factor of the fabric. This was termed as ‘R’ value. However, the performance of a loom shed also depends on the weave, the designs employed and the colours employed. Hence, it is not correct the compare the performance of one loom shed with other without understanding all the aspects. Finally, one should be able to assess the production possible and try to achieve it by avoiding unwanted stoppages and breakages.

14 Weaving - shuttle looms

14.1

Purpose of shuttle loom shed

Weaving is the interlacing of warp and filling yarns with each other to form cloth. A shuttle loom produces fabric by making use of shuttles for filling the weft in fabric. The purpose of a shuttle loom shed is to produce grey woven fabric of required quality in time by allocating appropriate looms and adapting appropriate weaving techniques like under pick, over pick, box motion etc.

14.1.1

What shuttle loom shed should do?

a. Understand the construction and design to be produced, the weave required and the component yarns of warp and weft for producing that fabric. b. Identify the suitable loom for the fabric to be woven. c. Follow up with sizing and pirn winding and get the required materials in time for completing the orders. d. Organize the weaving shed to get maximum possible utilisation and efficiency by supplying materials in time and allocate suitable persons for doing the job. e. Inspect and select the shuttles that are balanced and set the motion to get damage free fabrics and also accident-free working. f. Produce fabrics with least defects. g. Send the fabrics for grey inspection. h. Return the weavers beam to sizing section and empty pirns to pirn winding in time. i. Ensure quality of the fabric after each new beam gaiting by checking the first piece in detail.

14.1.2

What loom shed should not do?

a. Increase cost of weaving. b. Wasting yarns. c. Producing defective fabrics.

204

Handbook on Fabric Manufacture

d. Producing unwanted/unsold fabrics. e. Disturbing other sections by huge noise.

14.2

Quality of loom shed

Quality and performance of loom shed is measured by the following aspects: a. Efficiency of looms: Higher is better. Efficiency is worked out basing on the picks inserted in a given time and the standard speed of the loom. b. Percent of fresh quality fabrics: Higher is better. The fabric defects and the downgrading should be as minimum as possible. c. Wastes generated: Lower is better. d. Manufacturing cost per metre of fabrics woven: Lower is better. e. Reed space utilization: Higher the reed space utilization, the manufacturing cost per square metre of the fabric produced shall be less. f. Noise: - Lower is better. Noise not only affect the people working within loom shed but also is a disturbance for other sections.

14.3

General activities of a shuttle loom shed

Following are the normal activities of a shuttle loom shed. a. Understanding the design and production plan and allocating the looms for different activities considering complications in design and the workloads of the weaver. b. Allocating the workers on the machines considering their skills, capabilities and workloads agreed. c. Getting the weavers beam from drawing-in section before running out of the working beam. d. Incase running sort continues with new beam, the beam shall be knotted to the running loom without drawing-in. e. Getting the required weft yarn on pirns from weft winding section as per the requirement for the shift. f. Gaiting the looms and doing routine maintenance at the time of gaiting. g. Monitoring the humidity and temperature as per requirement by coordinating with the concerned engineering operator h. Running the looms and doffing the cloth at predetermined lengths. i. Getting the doffed fabrics inspected and taking corrective actions if needed.



Weaving - shuttle looms

205

j. Returning the empty beams to sizing/warping section as per the system. k. Returning the empty pirns to pirn winding section. l. Monitoring the efficiency of each loom. m. Periodically checking the shuttles and ensuring that they are balanced properly and setting the looms.

14.4

Knowledge required for running shuttle looms

a. Importance and functions of various mechanisms and infrastructure in the section. b. Different types of picking in shuttle looms like over pick and under pick. c. Different types of shuttle looms like plain power looms with over pick mechanism, power looms with under pick motion, box changing mechanism for checks, pirn changing auto looms, shuttle changing auto looms, dobby and jacquards application etc. d. Setting the looms, their timings to get trouble-free working. e. Precautions to be taken while running a shuttle loom. f. Fabric design, draft and peg plan and selecting loom suitable for the design. g. Production balancing – Importance and methodology for different product combinations. h. Role of humidity and temperature in maintaining quality and productivity i. Workloads, work allocation and standard working conditions appropriate to the weaving section. j. Calculation of production and efficiency, the industry norms and the factors affecting productivity. k. Importance of cleanliness and personal safety. l. Firefighting and first aid. m. Safety gadgets used in the factory and the workplace.

14.5 Routine activities of shuttle loom shed supervisor a. Taking charge from the previous shift supervisor regarding the machines working, material, count and type of warp and weft and

206

b.

c.

d. e.

f. g.

h.

i.

j. k.

l.

Handbook on Fabric Manufacture

lots working, designs, problems faced in the previous shifts, pending works and specific instructions, and getting a general feel of the problems encountered and being encountered. Understanding the production plan, production efficiency being achieved and allocating the looms for different designs as per the priorities given by the weaving in-charge. Taking round of each loom and assessing the weft availability in each shade to run the full shift or to complete the beam likely to run out in the shift. Coordinating with pirn winding and getting the required pirns as per plan and in time. Ensuring allocation of the available workmen on the machines considering their skills and capabilities. Following up with HRD in case of short of people and getting the required people for doing the job. Counselling the workers and motivating them for attending the work regularly and doing the work efficiently. Taking round in the department and understanding the actual position of materials being worked and the problems being faced on a continuous basis. Discussing with each weaver on the breakages in each loom and analysing design wise performance. Taking quality round, at least once in a shift and checking the pattern of both warp and weft, the ends and picks per inch, the fabric width, visible defects in the fabrics, stains and putting his signature at a corner in the fabric and entering the details of the problems in the log book. Checking all the new beams started in the previous shift. Ensuring that the machine parameters are set as required, viz. the speed, picks, reed space, temples, level of heald shafts, tension, length of cloth to be doffed and setting of pirn tip and tongue for easy withdrawal through the shuttle eye. Ensuring that the machines are started in time after the activities of beam gaiting, doffing of fabric, breakages and repairs. Ensuring that the machines are provided with required materials in time for all activities like beam gaiting, cloth doffing, preventive maintenance and waiting is avoided. Verifying and ensuring that fabric identification marks are put properly at the end of piece like design number, loom number, date and shift of doffing, and the length in metres in the piece according to the coding system in practice.



Weaving - shuttle looms

207

m. Checking the loom while the beam gaiting process is on for its condition, the beam being installed, handling of drop pins, healds and reeds and the quality of shuttle to minimise the breakages of ends. n. Ensuring that the empty beams removed are transported without delay to the designated area for warping and sizing sections. o. Ensuring that the empty pirns removed are cleaned and kept in designated place and sent back to pirn winding area. p. Monitoring the temperature and humidity of the weaving shed as per requirement of the material being worked. q. Ensuring that the hard wastes collected are disposed to waste section with proper identification and recording. r. Recording the stoppages of each machine reason wise and working out the production loss due to stoppages. s. Verifying the quality of fabrics by visiting the grey folding and inspection area and understanding the type of defects and the looms generating the defects, and arranging for the correction. t. Following with grey inspection for the first piece checking for new beams gaited, and getting the loom attended in time. u. Recording the activities in log book giving details of machines worked, designs worked, number of people engaged, efficiency achieved, problems faced and actions taken for the problems, stoppages and special instructions. v. Reporting the activities to weaving in-charge highlighting the problems faced, actions taken, present situation, and getting instructions for further actions.

14.6

Control points and check points

It is essential to have clarity on the points to be controlled to achieve the quality and targeted production and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘Control Points and Check Points’ and display them in the work area so that the supervisors refer and follow.

14.6.1

Control points in loom shed

1. Selection of design parameters like the type of loom, Weave, the total number of ends, the pattern, ends and picks per inch or per cm, grey

208

2.

3.

4.

5. 6. 7. 8. 9.

Handbook on Fabric Manufacture

width, length of piece to be doffed, the type and count of yarn used in warp and weft and the deadline for delivery. Selection of process parameters like speeds of looms, type of healds and reed, number of shafts, number of beams (single or double), number of hooks in case of jacquard, timings of different mechanisms in looms, settings of various motions like shedding, picking, beat-up, let-off and take up motions, weft feeler, cutter setting etc. Selecting the type of emery roller depending on the type of fibre and yarn, and type of temples. Fabric identification: marks to be put at the end of piece like design number, loom number, piece number, date and time of doffing and the length in metres in the piece according to the coding system. Deciding and maintaining required temperature and humidity in the loom-shed depending on the type of fibres being used and the type of looms. Evolving work norms and work allocation depending on the complexity of design and weave, and the type of machines. Engagement of trained and skilled employees for the design and type of weaves. Designing maintenance activities and implementing them. Indenting required spares depending on the changes in weave and materials. Maintaining the log book; recording the activities, problems faced and actions taken in each shift.

14.6.2

Check points in loom shed

Material related a. Check whether the weft pirns received are as per the requirement of the design for the loom, i.e., count of weft yarn, shade number and lot number. b. Check whether the quality of pirn winding is good without entanglements and sloughing-off problems. c. Check whether correct beams were gaited on the loom as per programme. d. Check the cross ends and loose ends in the beam gaited, and the extra ends left. Straighten the ends and draw extra end if possible. e. Verify the breaks due to beam quality. f. Verify the breaks due to weft quality.



Weaving - shuttle looms

209

Design related a. Whether the number of shafts/hooks taken is as per the design requirement? b. Whether the box motion set is matching the design requirement? c. Whether the loom is producing correct design as per requirement, i.e., ends and picks per inch on the loom, the pattern and repeat, grey width on loom, the selvedge formation and cover of fabric? Loom related a. Whether the beam is gaited correctly with uniform tension on both the sides? b. Whether the condition of reeds and healds used are good and as per requirement of the design, number of ends and count and the material? c. Whether the positioning of the reed is correct? d. Whether the let-off tension is uniform? e. Whether the emery roller is of correct type for the type of material being worked? f. Whether the shuttle is in good condition? g. Whether the condition of pins in the temple is good and the temple selected is of correct type for the type of material and fabric? h. Whether the drop pins used are of correct type? i. Whether the warp stop motion is working properly? j. Whether the weft stop motion is working properly? k. Whether the reserve pirns are filled in magazine properly in pirn changing auto looms? l. Whether the temple table position is properly set? m. Whether the shedding is set properly? n. Whether the picking force is adequate and the shuttle box is set properly? o. Whether the speed of the loom is as per standard? p. Whether the pick counter is acting properly? q. Whether the piece length set is proper? Process and quality related a. Whether the looms are giving the normal/expected efficiency? b. Whether the looms are producing fabrics of required quality without any defects?

210

Handbook on Fabric Manufacture

c. Whether any defects are being produced because of weaving machine problems? d. Whether loom quality rounds are taken as per schedule and supervisor’s initials are put? e. Whether the ends per inch and picks per inch are uniform at different places of the same fabric at different timings? f. Whether the temperature and humidity maintained near the looms are as per requirement of the material being produced? g. Whether the grey width is uniform and within the tolerance at different timings. h. Whether the quality and condition of the selvedge is correct as per design? i. Whether fabric cover is acceptable? j. Verify the reasons for stoppages of looms. k. What is the time taken for attending to stoppages and whether the time taken is reasonable? l. What action is taken on the first piece inspection reports on the looms? First piece checking related a. What is the first piece length decided for approval? b. Whether the first piece of the fabric was sent for inspection immediately after the piece was doffed? c. How much time was taken to receive the first piece inspection report? d. What remarks were made in the first piece inspection report? e. What actions were taken on the loom depending on the first piece report? f. Whether the loom was kept working or stopped after the first piece was sent for inspection? g. What happened to the material produced on the loom till it was corrected after going through the first piece report? h. Whether the fabric density was within the specified limits? Actions on final inspection reports a. What defects were noticed in final inspection relating to weaving operations? b. The extent of rejections like fents, rags and chindis.



Weaving - shuttle looms

211

c. The number of points as per the four point inspection system. d. Actions taken in the loom shed for arresting the defects. e. Whether all weavers were educated on the actions initiated? Workmen and work quality related a. Whether the workmen are adequately trained? b. Whether the number of persons engaged is as per plan? c. Whether the doffed fabrics are marked for identification as per plan? d. Whether the looms and the surroundings are maintained clean? e. Whether the unused materials are taken out from time to time? f. Whether the workers are reporting for work in time? g. Use of the safety gadgets like ear plug and masks by workmen as required. Maintenance related a. Whether the preventive maintenance is carried out as per schedule? b. Whether information was given to supervisors and weavers in advance relating to the preventive maintenance activities? c. Whether supervisor collected the list of problems from each weaver of each loom and gave to maintenance staff when the looms were taken for maintenance? Log book related a. Check whether the looms worked are entered properly indicating the weaver wise loom allocation and the design number worked. b. Recording the loom stoppages properly with correct reasons. c. Entering the beam gaited record along with design number in the log book. d. Check whether the instructions written in the log book are clear and simple. e. Check whether the first piece observations are entered in the log book. Management information system related (MIS) a. Check whether the pick readings were taken exactly at the specified time on each loom where shift-wise pick counters are not provided. b. Check whether the pick readings were entered in the MIS correctly. c. Check whether the stoppages of each loom are entered with reasons and timings in the computer system.

212

Handbook on Fabric Manufacture

d. Check whether the balance cuts on beams entered in MIS are correct. e. Check whether the beam gaited was correctly entered along with design card details in MIS. f. Check whether the weft received was entered properly against the same loom. g. Entering the materials returned back to yarn godown with details. h. Check whether all grey checking reports were entered in the system for MIS. i. Check the doffed metres entered in grey folding against the piece number. j. Matching the length actually measured while inspection with the length recorded while doffing. k. Check the entry of figures for production in metres as per picks and the actual length measured while grey checking in the system. General a. Whether the house keeping in the loom shed is okay? b. Whether the material handling is proper? c. Whether the reports are written in time and submitted? d. Whether the wastes are collected loom wise, weighed and recorded? e. Depositing of wastes to the waste godown with proper recording and labels. f. Returning the empty beams taken out from looms to preparatory department in time. g. Whether you received the loom shed in good condition from previous shift? h. Did you hand over the loom shed in clean working condition to your next shift? Daily checking a. Shed opening. b. Shuttle condition and weft insertion device. c. Pirn alignment and firmness in shuttle. d. Picker condition (bush condition for plastic picker). e. Picking force and timing. f. Shuttle checking in shuttle box. g. Weft fork and grate functioning.



Weaving - shuttle looms

Weekly checking a. Actual loom speed. b. Belt fork setting. c. Loom brake functioning. d. Warp protector motor functioning. e. Anti-crack motion functioning. At every beam fall a. Loom cleanliness and lubrication. b. Thorough cleaning of all oil holes. c. Free swinging of stop rod. d. Warp stop motion spring pressure. e. Shedding motion. f. Reed alignment and firmness. g. Count of emery and temples. h. Picks per inch. i. Temple mark defect in fabric.

Figure 14.1 Temple mark

At every new shuttle a. Shed opening. b. Picking motion. c. Shuttle box setting and condition. d. Swell setting. e. Spindle setting and picker centering.

213

214 f. g. h. i. j.

Handbook on Fabric Manufacture

Reed alignment and angle. Race board alignment. Box back angle. Warp protector motion. Shuttle guard condition and setting.

14.7

Normal problems in loom shed

The problems in loom shed can be grouped as yarn related, loom related and working related problems.

14.7.1

Yarn related problems

Normal Yarn related problems are warp streaks, weft bar, thick end and thick picks, coarse end, coarse pick, shade bar, fine end, tight end, pilling, bullet etc. 14.7.1.1

Warp streaks

Warp streaks are narrow, barre and dense stripes running along the warp direction. Main reasons are the variation in density of adjacent group of warp ends due to non-uniform dent spacing, wrong drawing-in, or count variations. The variations in lustre, reflectance of dye pick-up of adjacent groups arising out of differences in raw materials, blend composition or yarn constructions also contribute for streaks. 14.7.1.2

Weft bar It is a band running weft-wise across the full width of the cloth. The normal reasons are the periodic medium to long term irregularity in the weft yarn, count difference in weft, excessive tension in the weft feed package, especially in filaments, variability in pick density and difference in twist, colour or shade of adjacent group of picks, difference in blend composition or in the cottons used. 14.7.1.3

Thick end and thick picks

Higher diameter in yarn for a short distance can be due to improper piecing at spinning preparatory or drop in pressure on the drafting rollers for a short time. This also can happen due to not removing of spinners double, not piecing the end properly by removing the lapped materials, accumulation of fluff in condensers, cradles and in the necks of the top rollers.



Weaving - shuttle looms

215

Figure 14.2 Thick pick

14.7.1.4

Coarse end

Coarse end is a warp yarn that has a diameter too large, too irregular or that contains too much foreign material to make an even, smooth fabric. 14.7.1.5

Coarse pick

Coarse pick is a filling yarn that is too large and imperfect to appear to advantage in the final cloth. 14.7.1.6

Shade bar

Shade bar is a distinct shade change of short duration across the width of the fabric. This is normally due to a mix up of weft with different property.

Figure 14.3 Yarn mix up showing shade difference

14.7.1.7

Fine end

A defect in filament warp yarn consisting of thin places that occur when some of the filaments that should be in the warp yarn are absent, generally caused by improper reeling. Warp end of abnormally small diameter, i.e., long thin places of class I1 and I2 also is referred as fine end.

216

Handbook on Fabric Manufacture

14.7.1.8

Tight end

A tight end is a warp yarn in a woven fabric that was under excessive tension during weaving or shrank more than the normal amount. 14.7.1.9 Pilling

Fibre filaments that break in yarn due to friction leave small lumps of loose fibres on the surface and forms pilling. 14.7.1.10 Bullet

Bullets are low twisted double yarn seen weft wise in fabrics. Those are generally zero twisted parallel yarns. Practical causes of faults are improper functioning of bunch motion, incorrect yarn path through spindle, loose tensioners, capsule and spring working, insufficient yarn as bunch and knot is not applied after removing bunch yarn. 14.7.1.11

Variation in yarn Variation in yarn gives an unaccepted fabric which is non mendable.

Figure 14.4 Variation in yarn

14.7.2

Loom related problems

Normal loom related problems are reediness, reed mark, reed streak, misdraw (colour), broken picks, mispick, broken end, end out, float, pin marks, loom barre’, thick and thin places, box marks, shuttle traps, shuttle flying and smashes. 14.7.2.1 Reediness

These are very fine cracks or lines between groups of warp threads, caused due to excessive warp tension, late shedding, use of coarse reed with more



Weaving - shuttle looms

217

number of ends per dent, bent reed wires, improper spacing of reed wires, wrong drawing and insufficient opening of shed, i.e., tension difference between top and bottom shed lines during beat up. 14.7.2.2

Reed mark A crack between groups of warp ends, either continuous or at intervals, which can happen due to damaged reed or improper spacing of dents.

14.7.2.3

Reed streak A warp wise defect attributable to a bad reed like uneven reed space, bent reed wire, slant wire, damaged reed wire etc. Stripes in warp direction in cloth are also due to various reasons like run through and incorrect reed draw-in while drawing-in, damaged warp stop motion drop wires and damaged reed.

14.7.2.4

Misdraw (colour)

In woven fabrics, the drawing of coloured yarns through the loom harness contrary to the colour pattern and/or design weave is termed as Misdraw. 14.7.2.6

Broken picks

A filling yarn that is broken in the weaving of a fabric appears as a defect. Improper functioning of weft stop motion results in broken picks undetected and going in to the fabric.

Figure 14.5 Broken picks

14.7.2.7 Mispick

Mispick is a defect in woven fabric caused by a missing or out-of-sequence weft yarn. 14.7.2.8

Broken End

Broken end is a defect in fabric caused by a warp yarn that was broken during weaving or finishing. The possible reasons are insufficient warp strength and elongation in warp yarn, too high tension applied on warp while weaving, single warp threads without tension, i.e., loose ends in a beam, damaged warp

218

Handbook on Fabric Manufacture

stop motion wires, warp stop motion drop wires set too close and improper relative humidity for weaving. 14.7.2.9 End out

End out is a warp yarn that was broken or missing during weaving. If the warp stop motion detects and machine is stopped, the weaver mends the break. If the warp stop motion misses it then we get end out. 14.7.2.10 Float

Slack warp and faulty pattern card are the main reasons for a float in a woven fabric. Damaged or broken heald wire and foreign matter falling on warp can also cause floats.

Figure 14.6 Float

14.7.2.11

Pin marks

Poorly adjusted temple pins or damaged pins can lead to pin marks. The possible reasons are dirty temples, incorrect setting of temples, damaged temples, and close of shed of shedding device too early. 14.7.2.12

Loom barre’

Repetitive selvedge-to-selvedge unevenness in woven fabric usually attributed to a mechanical defect in the let-off or the take-up motion leads to loom barre. 14.7.2.13

Thick and thin places

These are similar to weft bar, but unlike weft bars, it repeats at intervals. They are mainly due to irregular let-off, incorrect setting of holding and releasing pawls on the ratchet wheel of take-up motion, gears of take-up motion not meshing properly, and gear wheel teeth worn out or broken.

14.7.2.14

Weaving - shuttle looms

219

Box marks

Box marks are due to something bruising or staining the weft while it is in or near the box. Main causes are dirty boxes, shuttle riding over the weft, oil from shuttle tongue, dirty shuttles, weft flying about too freely, oil splashes from loose cranks, oily spindles and buffers and dirty picking stick for under pick. 14.7.2.15

Shuttle traps

Entangled warp ends due to fluff falling on the warp, broken warp end entangled to adjacent end, knot with a long tail resulting in entanglement, snarls in yarn getting entangled, too much hairiness in yarns, weak picking, faulty shuttle checking, gear wheels slipping due to broken teeth, loose stop rod finger and uneven joint of flat belt are normal reasons for shuttle trap. 14.7.2.16

Shuttle flying

Fibrous yarns, knots with long tail ends, slack warp, uneven race board, small sheds, bottom line too high, worn pickers, swells giving twist to the shuttle as it leaves the box, early picking, late shedding, unbalanced shuttle, box spindle not set properly, box front not set properly and missing shuttle guard are the main reasons for shuttle flying. 14.7.2.17 Smashes



Daggers not working, frog spring ineffective, bad shuttle, improper boxing of shuttle, worn out picker, worn out transfer hammer, damaged pirn and entanglements are main causes of smashes.

Figure 14.7 Smash

220

Handbook on Fabric Manufacture

14.7.2.18

Bad selvedge

Improper shuttle wire tension, bent shuttle jaw, shuttle crack, more tension on selvedge yarns, late shedding resulting in rubbing of shuttle to the selvedge and improper selection of selvedge weave for the fabric being woven are the main reasons for bad selvedge.

Figure 14.8 Bad selvedge

14.7.2.19 Slough-off

Weft yarn has slipped from the pirn. Proper monitoring of strength and chase in pirn winding can solve this problem.

Figure 14.9 Slough-off

14.7.2.20 Jerk-in

Jerk in is an extra piece of filling yarn jerked by the shuttle into the fabric along with a regular pick of filling. 14.7.2.21 Knot

Knot is defined as a knob or lump formed by interlacing portions of one or more flexible strands or a quantity of yarn, or thread, which varies with the fibre; it consists a set of coils. Control in pirn winding, the winding to binding coils ratio can solve this problem. 14.7.2.22

Loom bar Loom bar is a change in shade across the width of a fabric, resulting from a build-up of tension in the shuttle before a filling change.



14.7.3

Weaving - shuttle looms

221

Working related problems

Normal working related problems in a loom shed are warp breaks, weft breaks, bad selvedge, double end, contamination of fluff, set mark and stop marks etc. 14.7.3.1

Warp breaks There are number of reasons for a warp yarn to break. Some examples are Excessive warp tension, Too small or too big shed formation, Bottom shed line beating down on sley race, Jerky movement of healds, Too early or too late shedding, Race board badly worn out, Healds catching each other, Sharp or rigid reed wires, Warp size accumulation on reed, Improper sizing, Improper humidity in the loom shed, A weaker warp yarn, A higher speed of loom, More number of ends per inch for the count being used and Less air space in reed. 14.7.3.2

Weft breaks

Normal reasons for a weft to break include Sloughing-off or loosely built pirn, Weft fork too far through the grate, Damaged tip of the pirn, Damaged porcelain guide in shuttle eye, Broken yarn not pieced in pirn winding and Vibrating spindles in pirn winding creating overlapping of coils on pirns. 14.7.3.3

Bad selvedge

More tension on selvedge yarns, late shedding, improper cutting at selvedge by cutter and improper selection of selvedge weave for the fabric being woven are the main reasons for bad selvedge. 14.7.3.4

Double end

Two ends that weave as one is termed as double end. This happens because of migration of a broken end to the adjacent reed space along with the neighbouring end. 14.7.3.5

Contamination of fluff Different fibres or foreign materials get mixed during spinning, winding or in weaving preparation stage, causing visual objection in fabric. The causes of fluff are improper cleanliness, not properly cleaning the machines after each doff and lot changes, improper suction of drafting zones of gill boxes and roving, improper cleaning of scrapper and scrapper plate after every lot change of doff, not using of curtains for partition of machines running on different colours, overhead cleaners of ply winding and ring frames blowing dust on running spindles or drums, material not covered to avoid fly and fluff accumulation, use of compressed air for cleaning machines while in working

222

Handbook on Fabric Manufacture

or while adjacent machine is working and use of common return air ducts and running different coloured fibres in the shed.

Figure 14.10 Contamination

14.7.3.6

Set mark Set mark is a defect in woven fabric resulting from prolonged loom stoppage. Because of the humid weather and the fine dust present in the atmosphere, the cloth exposed shall get slightly different colour and also some relaxation takes place. A combined effect gives a line in weft direction. 14.7.3.7

Stop mark (starting mark) Stopmarks are narrow band of different weave density across the width of a woven fabric caused by improper warp tension adjustment after a loom stop. A well trained weaver can reduce this type of defects. 14.7.3.8

Mix up of coarse yarn or multifold yarn

Mix up of coarse or multifold yarn show-off like a barre as shown in figure below:

Figure 14.11 Mix up of coarse yarn



Weaving - shuttle looms

14.8

223

Dos and don’ts for weaving

Understand clearly what are all the things that are supposed to be done without fail and what should not be done at any cost in a shuttle loom shed. Some examples are given below:

14.8.1 Dos a. Verify and understand the design in detail and the looms allotted for each design before starting your work. Ask for clarifications in case of any doubt. b. Stick to codes and other identification system agreed between sections. See that the fabric information like design number, loom number, date and shifts are clearly written on the doffed fabrics with accepted coding system. c. Feed correct RPM and pick in system where computerised monitoring of production and efficiency is practiced. d. Work for getting maximum utilisation and efficiency for which men are engaged. Monitor the stoppages, and see that the stopped machines are restarted. e. Have control on generation of wastes. Keep records of machine wise wastes and design wise wastes. f. Take periodic rounds and observe the quality and production of each loom. Check the problems and details personally rather than depending on a third person. g. Discuss with each worker relating to the problems they are facing related to loom and the material being worked. h. Insist on doffing the fabric as per predetermined cut length. i. Insist and get the first piece checking report as early as possible and take action on it. j. Insist on handing over the loom shed in clean condition from the previous shift and hand over a clean working shed to the next shift.

14.8.2 Don’ts a. Do not draw more material or produce more than the ordered quantity. b. Do not increase speeds of the machine or reduce picks per inch to get more productions. c. Do not decide on information to be attached to fabrics rolls by yourself; discuss with user department and fellow supervisors.

224

Handbook on Fabric Manufacture

d. e. f. g.

Do not engage people in the shift unless you have confirmed orders. Do not engage people above sanctioned strength. Do not allow a loom to work unless the noticed defects are rectified. Do not send the wastes to waste godown without weighing and recording. h. Do not send any materials out without proper labelling. i. Do not take decision on your own in case of weft shortage in any shade.

14.9

Responsibilities of weaving supervisor

a. Completing the assigned jobs and achieving the production and efficiency with quality besides maintaining the discipline, housekeeping and team working. b. Checking and ensuring that the condition of the machines is maintained for getting the quality and production as needed. c. Ensuring that all the programmed machines are kept working. d. Getting the machines started in time and achieving maximum utilisation. e. Ensuring clean working area all the time. f. Ensuring that all materials and records are kept in their respective places. g. Verifying the beam number and design details before the beams are taken for drawing-in or knotting. h. Checking the yarn details like the count, shade and quantity before taking them for weaving. i. Getting the hard wastes collected are put in designated places and disposed after documenting. j. Ensuring safe handling of the materials like beams, cones and fabrics and preventing wastes due to poor handling practices. k. Supplying fabrics in time to grey inspection and folding department as per programme. l. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline. m. To report HRD in case of any accidents and filling the accident reports in time. n. To help weaving in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.



Weaving - shuttle looms

14.10

225

Authorities of weaving supervisor

a. Questioning the jobber and workers when the work done is not satisfactory or when a problem is noticed. b. Sending memo to HRD in case of serious lapse in discipline by any of the employee working under him. c. Allotting or changing jobs to weavers and other workers considering their skills. d. Removing the beam in case of too many breaks due to stickiness or drawing-in problems and informing higher authorities regarding the quantity remaining and the reasons for removing. e. Recommending leave and/or permission to the subordinates in the section, while adhering to rules and regulations. f. Stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions.

14.11

Some hints for better performance

a. Always maintain dust free atmosphere at the reed and weft feeding area. b. Always maintain the required temperature and humidity. c. Ensure proper light so that the weaver can identify the broken thread fast. d. Do not give all tough sorts to a weaver. Make a combination of easy sorts and complicated sorts and allot on the looms. e. Ensure that all materials are brought and kept ready for gaiting or knotting before beam fall, and avoid time lost for gaiting. f. Develop the concept of team work between the gaiters, helpers and mechanics and encourage them to start the machine fast. g. Observe the quality and working of newly gaited beam and correct in the beginning itself.

14.12

Applicable formulae

Speed in picks per minute × Minutes per shift 100% Production in = metre per shift Picks per cm × 100 Loom efficiency % =

Actual picks produced in given time × 100 100% picks for the given time

226

Handbook on Fabric Manufacture

Weight of warp per = metre in grams

Ends per inch × reed space in inches × 39.4 × ( crimp% / 100 ) × 453.4 Count Ne of warp × 36 x 840

Weight of warp Total ends in fabric × 39.4 × ( crimp% / 100 ) × 453.4 = per metre in grams Count Ne of warp × 36 × 840

Weight of Weft = per metre in grams

Picks per inch × reed space in inches × 39.4 × ( crimp% / 100 ) × 453.4 Count Ne of weft × 36 × 840

15 Weaving - shuttle less looms

15.1

Purpose of shuttle less Loom shed

Weaving is the interlacing of warp and filling yarns with each other to form cloth. A shuttle less loom produces fabric at a very high speed without making use of the conventional shuttles. The weft insertion may be by using a projectile, rapier, air jet or water jet. The noise level is very low compared to shuttle looms. The purpose of a shuttle less loom shed is to produce grey woven fabric of required quality in time by allocating appropriate looms and adapting appropriate weaving techniques.

15.1.1

What loom shed should do?

a. Understand the design to be produced, the weave required and the component yarns of warp and weft for producing that fabric. b. Identify the suitable loom for the fabric to be woven. c. Organise the weaving shed to get maximum possible utilisation and efficiency by supplying materials in time and allocate suitable persons for doing the job. d. Produce fabrics with least defects.

15.1.2 a. b. c. d. e.

15.2

What loom shed should not do?

Increase cost of weaving. Wasting yarns. Producing defective fabrics. Producing unwanted/unsold fabrics. Disturbing other sections by huge noise.

Quality of loom shed

The quality of a shuttle less loom weaving shed is measured by following attributes. a. Efficiency of looms → Higher the efficiency, it is better. Efficiency is worked out as a percent of picks inserted to the picks should have been inserted for the time considered if there were no interruptions.

228

Handbook on Fabric Manufacture

b. Fresh quality fabrics → Shuttle less loom is expected to produce 100% fresh fabrics, i.e., without any defects that is objectionable. Any mistake in loom setting or maintenance or in the weaving preparation can produce an objectionable defect. c. Wastes → Any type of waste is expensive and it should be minimum. It may be weft yarn remnants, cut wastes from beams, fabric pieces cut-off due to defects or damages, wasting lubricants, wasting heald wires or drop pins or wastes of any type. d. Manufacturing cost per metre of fabrics woven → The competitiveness of a weaving shed depends on the cost of manufacturing, which is expressed as cost per square metre of the fabric produced. Lower the cost of manufacturing, the competitive shall be the weaving shed. e. Less noise disturbance for other sections.

15.3

General activities of a loom shed

1. Understanding the design and production plan and allocating the looms for different activities. 2. Allocating the workers on the machines considering their skills and workloads agreed. 3. Getting the weavers beam from drawing-in section. 4. In case a running sort continues with new beam, the beam shall be knotted to the running loom without drawing-in. 5. Getting the required weft yarn from yarn godown as per the requirement for the shift. 6. Gaiting the looms and doing routine maintenance at the time of gaiting. 7. Monitoring the humidity and temperature as per requirement by coordinating with the concerned engineering operator. 8. Running the looms and doffing the cloth at predetermined lengths. 9. Getting the doffed fabrics inspected and taking any corrective actions if needed. 10. Returning the empty beams to sizing/warping section as per the system. 11. Monitoring the efficiency of each loom. 12. Maintaining the loom accessories like heald wires, heald frames, reeds, drop pins, grippers etc. in a good condition. 13. Maintaining good housekeeping in the loom shed.



Weaving - shuttle less looms

229

15.4 Knowledge required for running shuttle less looms 1. Importance and functions of various mechanisms and infrastructure in the section. For instance knowledge of air quality, air compressor monitoring in case of air jet looms, water quality and water pump maintenance in case of water jet looms are necessary in additions to the basic loom mechanism, dobbies and jacquards used. 2. Precautions to be taken while running a loom. 3. Fabric design, draft and peg plan and selecting loom suitable for the design. 4. Production balancing: – Importance and methodology for different product combinations. 5. Role of humidity and temperature in maintaining quality and productivity. The weaving supervisor should have knowledge of monitoring the humidification plant to get the required humidity and temperature. 6. Workloads, work allocation and standard working conditions appropriate to the weaving section. 7. Calculation of production and efficiency, the industry norms and the factors affecting productivity. 8. Importance of cleanliness and personal safety. 9. Firefighting and first aid. 10. Safety gadgets used in the factory and the workplace.

15.5

Routine activities of loom shed supervisor

1. Taking charge from the previous shift supervisor regarding the machines working, materials in process, designs and lots working, problems faced in the previous shifts, pending works and specific instructions, and getting a general feel of the problems encountered and being encountered. 2. Understanding the production plan, production efficiency being achieved and allocating the looms for different designs as per the priorities given by the weaving in-charge. 3. Taking round of each loom and assessing the weft availability in each shade to run the full shift or to complete the beam if it is likely to run out in the shift. 4. Coordinating with yarn godown and getting the required weft yarns as per plan and in time.

230

Handbook on Fabric Manufacture

5. Ensuring allocation of the available workmen on the machines considering their skills and capabilities. Following up with HRD in case of short of people and getting the required people for doing the job. 6. Counselling the workers and motivating them for attending the work regularly and doing the work efficiently. 7. Taking round in the department and understanding the actual position of materials being worked and the problems being faced on a continuous basis. Discussing with each weaver on the breakages in loom and analysing design wise performance. 8. Taking quality round, at least once in a shift and checking the pattern of both warp and weft, the ends and picks per inch, the fabric width, visible defects in the fabrics, fringe width and stains, and putting his signature at a corner in the fabric and entering the details of the problems in the log book. 9. Checking all the new beams started in the previous shift. Ensuring that the machine parameters are set as required, viz. the speed, picks, reed space, temples, level of heald shafts, reserve in the weft accumulator, tension, cloth length to be doffed and setting of cone tip in line with the weft feeder. 10. Ensuring that the machines are started in time after the activities of beam gaiting, doffing of fabric, breakages and repairs. 11. Ensuring that the machines are provided with required materials in time for all activities like beam gaiting, cloth doffing, preventive maintenance and waiting is avoided. 12. Verifying and ensuring that fabric identification marks are put properly at the end of piece like design number, loom number, date and shift of doffing, and the length in metres in the piece according to the coding system. 13. Checking the loom while the beam gaiting process is on for its condition, the beam being installed, handling of drop pins, healds and reeds to minimise the breakages of ends. 14. Ensuring that the empty beams removed are transported without delay to the designated area for warping and sizing sections. 15. Ensuring that the empty cones removed from the weft creel are kept in designated place and sent to concerned area. 16. Monitoring the temperature and humidity of the weaving shed as per requirement of the material being worked. 17. Ensuring that the hard wastes collected are disposed to waste section with proper identification and recording.



Weaving - shuttle less looms

231

18. Recording the stoppages of each machine reason wise and working out the production loss due to stoppages. 19. Verifying the quality of fabrics by visiting the grey folding and inspection area and understanding the type of defects and the looms generating the defects, and arranging for the correction. 20. Recording the activities in log book giving details of machines worked, designs worked, number of people engaged, efficiency achieved, problems faced and actions taken for the problems, stoppages and special instructions. 21. Reporting the activities to weaving in-charge highlighting the problems faced, actions taken, present situation, and getting instructions for further actions. 22. Specific to Rapier looms a. Checking the looms for broken pick and loose picks. b. Checking the sole and tape of rapiers. c. Checking fringe lengths on both the sides. d. Ensuring sufficient stock of false selvedge spools. 23. Specific to Air Jet looms a. Checking the air consumption of each loom after beam gaiting or knotting and ensuring that the consumption is within the limit. b. To check air pressure of main line. c. To check fabric for weft loop defect. d. Checking the position of nozzles, viz. main nozzle, relay nozzles stretching nozzle. e. Checking air pressure at relay nozzles, control valve unit, stretching nozzle, and main nozzle for operating pressure, holding pressure for idle machine as well as running machine, and threading pressure. 24. Specific to Water jet looms a. Check the fringe width. b. Check for water leakages. c. Check water for purity – free from dust, fibres and minerals. d. Check performance of water pump supplying pressurized water. 25. Specific for Projectile looms a. Check the working of projectiles.

232

15.6

Handbook on Fabric Manufacture

Control points and check points

It is essential to have clarity on the points to be controlled to achieve the targeted production with quality and those to be checked to ensure the process in control in shuttle less looms. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘Control Points and Check Points’ and display them in the work area so that the supervisors refer and follow.

15.6.1 Control points in loom shed 1. Selection of design parameters; for example: The type of loom, weave, the total number of ends, the pattern, ends and picks per inch, grey width, length of piece to be doffed, the type and count of yarn used in warp and weft and the deadline for delivery. 2. Selection of process parameters like speeds of looms, type of healds and reed, number of shafts, number of beams (single or double), number of hooks in case of jacquard, timings of different mechanisms in looms, settings of various motions like shedding, picking, beat-up, let-off and take up motions, weft feeler, cutter setting, selecting the type of emery roller depending on the type of fibre and yarn, type of temples, setting of cut selvedge width and weave, and number of turns in the weft feeder. 3. Fabric identification: marks to be put at the end of piece like design number, loom number, piece number, date and time of doffing, and the length in metres in the piece according to the coding system. 4. The colour weft to be run in grey bottom design. 5. Deciding and maintaining required temperature and humidity in the loom-shed depending on the type of fibres being used and the type of looms. 6. Evolving work norms and work allocation depending on the complexity of design and weave, and the type of machines. 7. Engagement of trained and skilled employees. 8. Designing maintenance activities and implementing them. 9. Indenting required spares depending on the changes in weave and materials. 10. Maintaining the log book; recording the activities, problems faced and actions taken in each shift.



15.6.2

Weaving - shuttle less looms

233

Check points in loom shed

Material related a. The wefts received and the requirement of the design for the loom, i.e., Count of weft yarn, shade number and lot number. b. Check whether correct beams were gaited on the loom as per programme. c. Check the cross ends and loose ends in the beam gaited, and the extra ends left. Straighten the ends and draw extra end if possible. d. Verify the breaks due to beam quality. e. Verify the breaks due to weft quality. f. Whether the weft cones are having tail ends or not? Design related a. Whether the number of shafts/hooks taken is as per the design requirement? b. Verify the pattern requirements fed in the loom against the design given, i.e., synchronization of warp and weft pattern. c. Whether the loom is producing correct design as per requirement, i.e., ends and picks per inch on the loom, the pattern and repeat, grey width on loom, the selvedge formation and cover of fabric? Loom related a. Whether the beam is gaited correctly with uniform tension on both the sides? b. Whether the condition of reeds and healds used are good and as per requirement of the design, number of ends and count and the material? c. Whether the positioning of the reed is correct? d. Whether the let-off tension is uniform? e. The emery roller and its suitability for the type of material being worked. f. The condition of pins in the temple and its suitability for the type of fabric. g. Whether the drop pins used are of correct type? h. Whether the warp stop motion is working properly? i. Whether the weft stop motion is working properly?

234

Handbook on Fabric Manufacture

j. Whether the weft feeders are set properly? k. Whether the weft tension is adjusted properly? l. Whether the weft feeler is functioning properly? m. Whether the reserve cones are positioned properly in the weft creel? n. Whether the temple table position is properly set? o. Whether the shedding is set properly? p. The feeder setting viz. positioning, stopper setting and filling length. q. The speed of the loom and the standard. r. Whether the pick counter is acting properly? s. Whether the piece length set is proper? Process and quality related a. Whether the looms are giving the normal efficiency? b. Whether the looms are producing fabrics of required quality without any defects due to weaving machine problems? c. Loom quality rounds taken as per schedule and supervisor’s initials on fabric. d. Uniformity of ends per inch and picks per inch at different places of the same fabric at different timings. e. Maintaining the temperature and humidity near the looms as per requirement of the material being produced. f. Whether the grey width is uniform and within the tolerance at different timings. g. Whether the quality and condition of the selvedge is correct as per design? h. Whether fabric cover is acceptable? i. What are the reasons for stoppages of looms? j. The time taken for attending to stoppages and whether the time taken is reasonable. k. What action is taken on the first piece inspection reports on the looms? l. Whether the cut selvedge is as per plan? First piece checking related a. What is the first piece length decided for approval? b. Time taken for sending the first piece of the fabric for inspection after the doffing.



Weaving - shuttle less looms

235

c. How much time was taken to receive the first piece inspection report? d. What remarks were made in the first piece inspection report? e. What actions were taken on the loom depending on the first piece report? f. Whether the loom was kept working or stopped after the first piece was sent for inspection? g. What happened to the material produced on the loom till it was corrected after going through the first piece report? h. Whether the fabric density was within the specified limits? Actions on final inspection reports a. What defects were noticed in final inspection relating to weaving operations? b. The extent of rejections like fents, rags and chindis? c. The number of points as per the four point inspection system, and actions were taken? d. Actions taken in the loom shed for arresting the defects? e. Whether all weavers were educated on the actions initiated? Workmen and work quality related a. Whether the workmen are adequately trained? b. Whether the number of persons engaged is as per plan? c. Whether the doffed fabrics are marked for identification as per plan? d. Whether the looms and the surroundings are maintained clean? e. Whether the unused materials are taken out from time to time? f. Whether the workers are reporting for work in time? g. Whether the safety gadgets like ear plug and masks are used by workmen as required? Maintenance related a. Whether the preventive maintenance is carried out as per schedule? b. Whether information was given to supervisors and weavers in advance relating to the preventive maintenance activities? c. Whether supervisor collected the list of problems from each weaver of each loom and gave to maintenance staff when the looms were taken for maintenance?

236

Handbook on Fabric Manufacture

Log book related a. Check whether the looms worked are entered properly indicating the weaver wise loom allocation and the design number worked. b. Whether the loom stoppages are recorded properly with correct reasons? c. Check recording of the beam gaited along with design number. d. Check whether the instructions written in the log book are clear and simple. e. Check whether the first piece observations are entered in the log book. Management information system related a. The pick readings taken on each loom. b. Check whether the pick readings were entered in the MIS correctly. c. Entering of the stoppages of each loom with reasons and timings in the system. d. Check whether the balance cuts on beams entered in MIS are correct. e. Entering of the beam gaited along with design card details in MIS. f. Check whether the weft received was entered properly against the same loom. g. Entering the materials returned back to yarn godown properly in the system. h. Check whether all grey checking reports were entered in the system for MIS. i. Check whether the doffed metres entered in grey folding is correct against the piece number, and whether the length actually measured while inspection matches with the length recorded while doffing. j. Check whether the figures entered for production in metres as per picks and the actual length measured while grey checking were entered without mistake in the system. General a. Whether the house keeping in the loom shed is okay? b. Whether the material handling is proper? c. Whether the reports are written in time and submitted? d. Whether the wastes are collected loom wise and weighed? e. Depositing the wastes to the waste godown with proper recording and labels.



Weaving - shuttle less looms

237

f. Delivering the empty beams taken out from looms to preparatory department in time. g. Whether you received the loom shed in good condition from previous shift? h. Did you hand over the loom shed in clean working condition to your next shift?

15.7

Normal problems in loom shed

The problems in loom shed can be grouped as yarn related, loom related and working related.

15.7.1

Yarn related problems

Normal yarn related problems are warp streaks, weft bar, thick end and thick picks, coarse end, coarse pick, shade bar, fine end, tight end, pilling and bullet etc. 15.7.1.1

Warp streaks

Warp streaks are narrow, barre and dense stripes running along the warp direction. Main reasons are the variation in density of adjacent group of warp ends due to non-uniform dent spacing, wrong drawing-in, or count variations. Also, the variations in lustre, reflectance of dye pick-up of adjacent groups arising out of differences in raw materials, blend composition or yarn constructions contribute for streaks. 15.7.1. 2

Weft bar

It is a band running weft-wise across the full width of the cloth. The normal reasons are the periodic medium to long term irregularity in the weft yarn, count difference in weft, excessive tension in the weft feed package, especially in filaments, variability in pick density and difference in twist, colour or shade of adjacent group of picks, difference in blend composition or in the cottons used. 15.7.1.3

Thick end and thick picks

Higher diameter in yarn for a short distance can be due to improper piecing at spinning preparatory or drop in pressure on the drafting rollers for a short time. This also can happen due to not removing of spinners double, not piecing the end properly by removing the lapped materials, accumulation of fluff in condensers, cradles and in the necks of the top rollers.

238

Handbook on Fabric Manufacture

15.7.1.4

Coarse end

Warp yarn that has a diameter too large, too irregular or that contains too much foreign material to make an even, smooth fabric. 15.7.1.5

Coarse pick Filling yarn that is too large and imperfect to appear to advantage in the final cloth. 15.7.1.6

Shade bar

A distinct shade change of short duration across the width of the fabric. This is normally due to a mix up of weft with different property. 15.7.1.7

Fine end Fine end is a defect in filament warp yarn consisting of thin places that occur when some of the filaments that should be in the warp yarn are absent, generally caused by improper reeling. Warp end of abnormally small diameter, i.e., long thin places of class I1 and I2 also is referred as fine end. 15.7.1.8

Tight end

Warp yarn in a woven fabric that was under excessive tension during weaving or shrank more than the normal amount. 15.7.1.9 Pilling

Fibre filaments that break in yarn due to friction leaving small clumps of loose fibres on the surface. 15.7.1.10 Bullet

Bullets are low twisted double yarn seen weft wise in fabrics. Those are generally zero twisted parallel yarns. Practical causes of faults are improper functioning of bunch motion, incorrect yarn path through spindle, loose tensioners, capsule and spring working, insufficient yarn as bunch and knot is not applied after removing bunch yarn.

15.7.2

Loom related problems

The normal loom related problems are reediness, reed mark, reed streak, misdraw (colour), weft loops, broken picks, half pick, mispick, broken end, end out, float, pin marks, Loom Barre’ , Thick and Thin places etc. 15.7.2.1 Reediness

These are very fine cracks or lines between groups of warp threads, caused due to excessive warp tension, late shedding, use of coarse reed with more



Weaving - shuttle less looms

239

number of ends per dent, bent reed wires, improper spacing of reed wires, wrong drawing, and insufficient troughing of shed, i.e., tension difference between top and bottom shed lines during beat up. 15.7.2.2

Reed mark A crack between groups of warp ends, either continuous or at intervals, which can happen due to damaged reed or improper spacing of dents. 15.7.2.3

Reed streak Reed streak is a warp wise defect attributable to a bad reed like uneven reed space, bent reed wire, slant wire, damaged reed wire etc. Stripes in warp direction in cloth are also due to various reasons like run through and reed draw-in is not correct while drawing-in, damaged warp stop motion drop wires, damaged reed, air hoses to relay nozzles leaking, incorrect layout of relay nozzles and dirty nozzles. 15.7.2.4

Misdraw (colour)

In Woven fabrics, the drawing of coloured yarns through the loom harness contrary to the colour pattern and/or design weave is termed as Misdraw. 15.7.2.5

Weft loops

Loops from weft project from the surface of cloth either on one or both sides of a cloth because of a small portion of weft getting caught by the warp threads. The main reasons are late shedding, low warp tension and use of bad temples. There are some more reasons as follows: • In air jet looms, sometimes the filling thread does not reach filling stop motion 1, but remains as loop left cloth half. Left filling thread end is not cut or not cut cleanly. The possible causes are low warp tension, back rest roll too high and upper shed position too loose, thread start set early in filling insertion, dirty or worn-out filling thread scissors, dirty filling thread clamp, incorrect setting of filling thread clamp, feeder position to nozzles improper and main nozzle to tandem nozzle positioning not proper. • Filling thread end does not reach filling stop motion but springs back and remains curled in the cloth. The possible reasons are the operating pressure for main nozzles/tandem nozzles too high, filling insertion relay nozzles blowing duration too short, thread arrival too late, relay nozzles air pressure not correct, dynamic pressure too low for reed and relay nozzles, filling thread not held by stretching nozzle, air hose leaking in stretching nozzle, defective solenoid valve for stretching nozzle, weaving shed setting incorrect, filling thread touches warp

240

Handbook on Fabric Manufacture

•

•

•

•

•

•

•

because of knots or buttons in warp, any single warp thread with low tension, leno thread tension too low, leno device dirty, relay nozzles dirty, improper positioning of main nozzle and tandem nozzle. Filling thread end does not reach filling stop motion but lies in RHS selvedge. Possible causes are fibre fly deposits in selvedge, selvedge break, thread arrival timing set too late, leno thread tension too low, leno device dirty, shed closing early for RHS leno device. Filling thread end does not reach filling stop motion, but twists around warp threads. The possible reasons are thread start in filling insertion menu set too early, fibre fly deposits on warp and clinging warp thread material. Filling thread end does not reach filling stop motion but remains stringed on LHS. Possible causes are filling thread fed into wrong main nozzle, (filling insertion only through holding pressure), feeder releases only one winding, air pressure hose to main nozzle and tandem nozzle is defective and switching time for main nozzle/tandem nozzle solenoid valve too long. Filling thread end does not reach filling stop motion, but forms a sling in LHS selvedge. Possible reasons are fibre fly deposits in LHS selvedge, selvedge break, thread starting set too early in filling insertion menu. Filling thread end does not reach filling stop motion 1, but forms a snarl in right cloth half. The possible reasons are too high operating pressure for main nozzle and tandem nozzle, holding air pressure at nozzles are too high for running machine, thread insertion set too early in menu, incorrect setting of weaving shed, shed opening too small, too low air pressure in relay nozzles, and low dynamic air pressure. Small loops on the left side of the cloth are found due to loose filling in air jet looms. The possible reasons are blowing duration of main nozzle/tandem nozzle too long for weft insertion, blowing duration of first relay nozzle group too long, thread arrival too late, main nozzle holding pressure too high, relay nozzles air pressure too low, feeder too far forwards at control cabinet and close of shed too early. Filling thread springs back and remains snarled in RHS cloth edge. The possible cause is too short length of filling thread in the stretching area.

15.7.2.6

Broken picks A filling yarn that is broken in the weaving of a fabric appears as a defect is termed as broken pick. Improper functioning of weft stop motion results in broken picks undetected and going in to the fabric.



Weaving - shuttle less looms

241

In air jet looms, sometimes the filling thread end does not reach filling stop motion and ends in the centre of the cloth. The possible reasons are fibre fly depositing before tandem nozzle and main nozzle, filling thread knot before or in tandem nozzle or main nozzle (injector diameter too small for the yarn) and feeder thread hooked on feeder drum. Malfunctioning of solenoid valve of relay nozzles also can lead to such problem. 15.7.2.7

Half pick

In case of rapier looms, if the second rapier does not collect the weft, it shall stop in between, and we get half pick. 15.7.2.8 Mispick

A defect in woven fabric caused by a missing or out-of-sequence yarn. 15.7.2.9

Broken end A defect in fabric caused by a warp yarn that was broken during weaving or finishing. The possible reasons are insufficient warp strength and elongation in warp yarn, too high tension applied on warp while weaving, single warp threads without tension, i.e., loose ends in a beam, damaged warp stop motion wires, warp stop motion drop wires set too close and improper relative humidity for weaving. 15.7.2.10

End out

A warp yarn that was broken or missing during weaving is termed as End Out. If the warp stop motion detects and machine is stopped, the weaver mends the break. If the warp stop motion misses it then we get end out. 15.7.2.11 Float

Slack warp and faulty pattern card are the main reasons for a float in a woven fabric. Damaged or broken heald wire and foreign matter falling on warp can also be a cause for floats. 15.7.2.12

Pin marks

Poorly adjusted temple pins or damaged pins can lead to pin marks. In the case of air jet looms, we sometimes get warp or filling thread bursting in temple area. The possible reasons are dirty temples, incorrect setting of temples, damaged temples, and close of shed of shedding device too early. 15.7.2.13

Loom barre’ Repetitive selvedge-to-selvedge unevenness in woven fabric usually attributed to a mechanical defect in the let-off or the take-up motion is termed as Loom barre.

242

Handbook on Fabric Manufacture

15.7.2.14

Thick and thin places

Thick and thin places are similar to weft bar, but unlike weft bars, it repeats at intervals. They are mainly due to irregular let-off, incorrect setting of holding and releasing pawls on the ratchet wheel of take-up motion, gears of take-up motion not meshing properly, and gear wheel teeth worn out or broken.

15.7.3

Working related problems

The working related problems in a shuttle less loom shed are warp breaks, weft breaks, bad selvedge, double end, contamination of fluff, set mark, stop mark and double pick etc. 15.7.3.1

Warp breaks

There are number of reasons for a warp yarn to break. Some examples are Excessive warp tension, too small or too big shed formation, bottom shed line beating down on sley race, jerky movement of healds, too early or too late shedding, race board badly worn out, healds catching each other, sharp or rigid reed wires, warp size accumulation on reed, improper sizing, improper humidity in the loom shed, a weaker warp yarn, a higher speed of loom, more number of ends per inch for the count being used and less air space in reed 15.7.3.2

Weft breaks Normal reasons for a weft to break include High weft tension, back stitches in cones fed as weft, sloughing-off or loosely built weft package, selvedge ends cutting the weft, weft fork too far through the grate, improper alignment of cone in weft feeder, lower twist in weft resulting in weft opening out in air-jet looms, grippers missing the picks, improper knotting of tail ends, and rough handling of cones. Apart from actual weft breaks, the looms may stop indicating a broken weft due to various reasons. They are whole or uncut filling thread at filling stop motion, torn part of filling thread at filling stop motion, photocell on the weft feeder is dirty, number of reserve windings are too high, feeder drum diameter too large, thread tension on feeder drum too low, wrong feeder position, holding air pressure for running machine too high in case of air jet looms, filling thread insertion speed too high. In case of Air jet looms, torn part of filling thread at filling stop motions may be due to relay nozzles air pressure too high, holding air pressure for running machine too high, stretching nozzle air pressure too high, thread arrival too early, too many relay nozzles blowing at thread arrival, feeder release too late, thin places or splices in filling yarn and machine speed too high.



Weaving - shuttle less looms

243

In air jet looms, sometimes the filling stop motion 1 detects arrival of thread whereas the second stop motion detects a torn thread. The normal reasons are feeder position to main nozzle/tandem nozzle incorrect, stretching nozzle air pressure too high, holding air pressure for running machine too high in main nozzle, filling thread insertion speed too high in relay nozzles, thin places or splices in filling yarn, filling thread clamping pressure too high. 15.7.3.3

Bad selvedge

More tension on selvedge yarns, late shedding, improper cutting at selvedge by cutter and improper selection of selvedge weave for the fabric being woven are the main reasons for bad selvedge. 15.7.3.4

Double end When two ends are woven as one it is called as Double End. This happens because of migration of a broken end to the adjacent reed space along with the neighbouring end. 15.7.3.5

Contamination of fluff

Different fibres or foreign materials get mixed during spinning, winding or in weaving preparation stage, causing visual objection in fabric. This is termed as contamination of fluff. The causes are improper cleanliness, not properly cleaning the machines after each doff and lot changes, improper suction of drafting zones of gill boxes and roving, improper cleaning of scrapper and scrapper plate after every lot change of doff, not using of curtains for partition of machines running on different colours, overhead cleaners of ply winding and ring frames blowing dust on running spindles or drums, material not covered to avoid fly and fluff accumulation, use of compressed air for cleaning

Figure 15.1 Fluff contamination

244

Handbook on Fabric Manufacture

machines while in working or while adjacent machine is working and use of common return air ducts and running different coloured fibres in the shed. In case of air jet looms, fibre fly deposits on feeders and/or filling tensioner and dirty filling thread scissors also create fly slubs. 15.7.3.6

Set mark

Set mark is a defect in woven fabric resulting from prolonged loom stoppage. Because of the humid weather and the fine dust present in the atmosphere, the cloth exposed shall get slightly different colour and also some relaxation takes place. A combined effect gives a line in weft direction. 15.7.3.7

Stop mark (starting mark)

Stop mark is a narrow band of different weave density, across the width of a woven fabric, caused by improper warp tension adjustment after a loom stop. A well trained weaver can reduce this type of defects. 15.7.3.8

Double pick

When a weft runs out, the last portion of the cone which was cut by the scissor is not sucked by the suction tube and gets entangled with the weft yarn drawn from new weft. This is referred as ouble pick. 15.7.3.9

Oil stains

Oil stain is a common problem in grey fabrics, which can be due to improper wiping and cleaning of machines after maintenance, workers not cleaning their hands while touching a fabric, excess oiling and oil spilling, keeping fabric roll on a dirty floor and so on. It is suggested to use oils that are easily washable to ensure less loss.

Figure 15.2 Oil stains



Weaving - shuttle less looms

15.7.3.10

245

Section mark

A fabric defect consisting of marks running warp wise in an evenly repeating pattern, caused by the improper setting of sections in silk system (or indirect) warping.

15.8

Dos and don’ts for supervisor

Understand clearly what are all the things that are supposed to be done without fail and what should not be done at any cost. Some examples are given below:

15.8.1 Dos a. Verify and understand the design in detail and the looms allotted for each design before starting the work. b. Stick to codes and other identification system agreed between sections. See that the fabric information like design number, loom number, date and shifts are clearly written on the doffed fabrics with accepted coding system. c. Feed correct RPM and pick in system. d. Work for getting maximum utilisation and efficiency for which men are engaged. Monitor the stoppages, and see that the stopped machines are restarted. e. Have control on generation of wastes. Keep records of machine wise waste generated and design wise waste generated. f. Take periodic rounds and observe the quality and production of each loom. g. Discuss with each worker relating to the problems they are facing related to loom and the material being worked. h. Insist on doffing the fabric as per predetermined cut length. i. Insist and get the first piece checking report as early as possible. j. Insist on handing over the loom shed in clean condition from the previous shift and hand over a clean working shed to the next shift.

15.8.2

Don’ts

a. Do not draw more material or produce more than the ordered quantity. b. Do not increase speeds of the machine or reduce picks per inch to get more productions.

246

Handbook on Fabric Manufacture

c. Do not decide on information to be attached to fabrics rolls by yourself; discuss with user section and Quality Assurance. d. Do not engage people in the shift unless you have confirmed orders. Do not engage people more than sanctioned strength. e. Do not allow a loom to work unless the noticed defects are rectified. f. Do not send the wastes to waste godown without weighing and recording. g. Do not send any materials out without proper labelling. h. Do not take decision on your own in case of weft shortage in any shade.

15.9

Responsibilities of weaving supervisor

a. Completing the assigned jobs and achieving the production and efficiency with quality besides maintaining the discipline, housekeeping and team working. b. Ensuring that the condition of the machine is maintained for getting the quality and production as needed. c. Ensuring that all the programmed machines are kept working. d. Getting the machines started in time and achieving maximum utilisation. e. Ensuring clean working area all the time. f. Ensuring all materials and records are kept in their respective places. g. Verifying the beam number and design details before the beams are taken for drawing-in or knotting. h. Checking the yarn details like the count, shade and quantity before taking them for weaving. i. Getting the hard wastes collected are put in designated places and disposed after documenting. j. Ensuring safe handling of the materials like beams, cones and fabrics and preventing wastes due to poor handling practices. k. Supplying fabrics in time to grey inspection and folding department as per programme. l. Maintaining discipline in the section and informing the higher authorities in case of any serious breach in discipline. m. To report HRD in case of any accidents and filling the accident reports in time. n. To help weaving in-charge in investigating the root cause for poor quality, deviation in systems, breach of discipline and poor productivity.



Weaving - shuttle less looms

15.10

247

Authorities of weaving supervisor

1. Questioning the jobber and workers when the work done is not satisfactory. 2. Sending memo to HRD in case of a lapse in discipline by any one working under him. 3. Allotting or changing jobs to weavers and other workers considering their skills. 4. Removing the beam in case of too many breaks due to stickiness or drawing-in problems and informing higher authorities regarding the quantity remaining and the reasons for removing. 5. Recommending leave and/or permission to the subordinates in the section, while adhering to rules and regulations. 6. Stopping the production in case of any deviations found in the quality and informing the superiors for necessary corrective actions.

15.11

Some hints for better performance

a. Always maintain dust free atmosphere at the reed and weft feeding area. b. Always maintain the required temperature and humidity. c. Ensure proper light so that the weaver can identify the broken thread fast. d. Do not give all tough sorts to a weaver. Make a combination of easy sorts and complicated sorts and allot the looms. e. Ensure that all materials are brought and kept ready for gaiting or knotting before beam fall, and avoid time lost for gaiting. f. Develop the concept of team work between the gaiters, helpers and mechanics and encourage them to start the machine fast. g. Observe the quality and working of newly gaited beam and correct in the beginning itself.

15.12

Applicable formulae

Speed in picks per minute × Minutes per shift 100%Production in = metre per shift Picks per cm × 100 Loom efficiency % =

Actual picks produced in given time × 100 100% picks for the given time

248

Handbook on Fabric Manufacture

Weight of warp = per metre in grams

Ends per inch x reed space in inches × 39.4 × ( crimp% / 100 ) × 453.4 Count Ne of warp × 36 × 840

Total ends in fabric x 39.4 × ( crimp% / 100 ) × 453.4 Weight of warp = per metre in grams Count Ne of warp × 36 × 840

Weight of weft = per metre in grams

Picks per inch × fabric width in inches × 39.4 × ( crimp% / 100 ) × 453.4 Count Ne of warp × 36 × 840

15.12.1 Expected production and work loads Method of working out expected production and the workloads that can be given to a weaver  

 

Gripper

Water jet

Rapier

Air jet

A

Speed in P.P.M

320

480

550

700

B

Pick per inch

62

64

80

84

C

100% Production in Metres for 8 hours (A*480/B)/39.4

62.88

91.37

83.76

101.52

D

Number of breaks per loom hour (example)

2

2

0.5

3.5

D1

Normal time to attend a break in minutes

2

2

1.5

1.5

D2

Interference time approximate minutes

1.0

1.0

1.0

1.0

E

Total stoppage time to attend breaks in min (D × 8(D1 + D2))

48

48

10

70

F

Piece length in Mtrs

100

100

100

250

G

Time for completing one piece in hours ( F/C)*8

12.72

8.76

9.55

19.70

H

Time for removing doff in minutes

1.5

1.5

1.5

1.5

I

Time spent in a shift for removing doffs (H × C/F)

0.94

1.37

1.26

0.61

J

Average beam length Metres

2000

2000

2000

1000



Weaving - shuttle less looms

 

 

K

Number of shifts to run a beam at 100% eff (J/C)

L

Time for beam gaiting Hrs

M

249

Gripper

Water jet

Rapier

Air jet

31.81

21.89

23.88

9.85

3

3

3

3

Time lost for beam gaiting per shift in minutes L × (C/J) × 60

5.66

8.22

7.54

18.27

N

Total time lost in a shift (E+I+M)

54.60

57.59

18.79

88.88

 

Expected efficiency = {(480 − N)/480) × 100

88.62

88.00

96.08

81.48

16 Grey fabric inspection

16.1 Purpose Normally, the visual inspection is carried-out on the textile products to examine the occurrence of yarn defects, fabric defects, fabrication defects, design and colours besides specification particulars and followed by drawing the samples for testing to know the hidden quality parameters such as shrinkage, strength, colour fastness etc. The purpose of grey fabric inspection is to inspect and grade the grey fabrics produced at the loom shed considering the level of defects to help taking suitable actions for their utilisation. The purpose can be listed as follows: • To ensure fabric produced is of required quality. • To identify the looms producing defects and taking corrective action. • To prevent losses after cutting the fabric for making a garment because of fabric defects. • To classify the products according to the different quality based on the demands of the buyer/market or client.

16.1.1

What grey inspection should do?

a. Noting down the design, sort and loom number and verifying the length of roll received for inspection and comparing with the length marked or written in doffing slip. b. Inspecting the grey fabric for defects and mark/flag the defects for taking action. c. Trimming the loose or projecting threads. d. Informing the weaving supervisors regarding the defects observed so that they can take suitable correcting actions. e. Sending the inspected grey fabrics to grey warehouse for delivering to next process.

16.1.2

What grey inspection should not do?

a. Should not cut the fabric at defective portions. b. Should not pull the loose threads; but cut with a sharp scissor.



Grey fabric inspection

16.2

251

General activities in grey inspection

a. The fabric rolls are received from loom shed. b. Inspector is given special instruction if any by writing on job card by supervisor as per instruction of in-charge of weaving. c. Checking the details of fabric received and conforming before taking them for checking. d. Cleaning the inspection table and the surrounding before start of the work. e. Checking the fabric weight and comparing with the ‘should be weight’ as per design. If the weight is differing than the norms, rechecking shall be done and the concerned persons shall be given alarm to take decision. f. Setting the length counter after the fabric end reaches the inspection area. g. Switching on lights both below the table and above the table. h. Checking the back and face side of the fabric first and then inspecting the goods for visible defects as per the required standards, for e.g. four points system. i. Marking the defects with sticker at the location of defect or with a marker (sticker, tag etc.) at selvedge edge. j. Informing the supervisor regarding the materials checked and taking Instruction for further checking. If damages are found, the counting of defects is not done and the incharge is informed to take decision. k. Keeping the inspected fabric roll on the fabric stand and putting the tag.

16.3

Knowledge required for Fabric inspection

• The parts and functions of a fabric inspection machine for woven fabrics and knitted fabrics. • The standards of illumination required for inspection. 1200 Lux is recommended. • Allocating penalty points to the defects as per the guidelines. Following is the guidelines for 4 point inspection system. Size of defects Points assigned

Inches

Cm

1

23Cm

Top light Tension regulators

Fabric in the inspection area

Position of inspector

Fabric for inspection

Platform for keeping fabric

Figure 16.1 Schematic diagram of fabric inspection machine.

Figure 16.2 Illumination system for fabric inspection.



Grey fabric inspection

253

Distinguishing major defects: A major defect is any defect that would cause a final garment to be considered as second. Major woven fabric defects include but are not limited to slubs, holes, missing yarns, yarn variation, end out, soiled yarns, and wrong yarn. Understanding the difference between major and minor faults and not allotting any penalty marks to minor defects is the real challenge and indicate maturity of an inspector. Allocating points: Not to assign more than 4 penalty points for any single defect. Consecutive linear meter in which a continuous running defect exceeds 9 inches (23 cm) shall be allotted 4 points. In case a defect runs for the full width of the fabric, 4 points shall be allotted. Points per 100 square metres =

16.4

Total Points for the roll × 100, 000 Inspected Meters × Fabric Width ( MM )

Control points and check points

It is essential to have clarity on the points to be controlled to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘Control Points and Check Points’ and display them in the work area so that the supervisors refer and follow.

16.4.1 a. b. c. d. e. f. g. h.

Control points

Fabric speed on inspection machine. Level of illumination. Side mirror in case of knitted fabrics. Angle at which the inspection is done, i.e., 45˚ to 60˚ The distance for the inspector’s eye to the fabric being inspected. Method of marking the defects. Method of reporting. Periodic checking of inspectors for colour blindness.

16.4.2

Check points

Material related a. The fabric details like loom number, sort number, design number and length marked on the piece. b. Whether it is first piece or a running piece?

254

Handbook on Fabric Manufacture

Machine related a. The angle of inspection – it should be between 45˚and 60˚. b. Whether the light is sufficient – Minimum 1200 lux is required. c. Whether the glass on inspection table is clean and light is uniformly distributed? Setting related a. What is the speed of inspection set? – It should not exceed 15 metres per minute. b. Whether the side mirror is set properly? c. Whether length counter is set to zero when the fabric reached inspection area? Performance related a. Whether the meters inspected per inspector is as per agreement? b. Whether the reporting is done properly? Documentation related a. Whether the details of fabrics inspected are documented correctly? b. Whether the grading done is documented and informed to weaving and processing? c. Whether the length of each roll is checked and documented. d. Whether the weight of each roll is checked and documented? Work practice related a. Whether the inspection tables were cleaned before starting inspection of each roll? b. Whether the defects are marked clearly and shown to the concerned? Log book related a. Whether the priorities for inspection are written in the log book? b. Whether the rolls in stock waiting for inspection are mentioned in the log book? Management information system related Check whether the data entered for MIS is correct like c. Loom number, d. Sort number, e. Design number



Grey fabric inspection

f. g. h. i. j. k. l.

255

Length in meters as per pick reading on loom Actual length in metres found on cloth Total weight of fabric roll Standard weight per linear metre Actual weight per linear metre Number of points as per the inspection system Grading of fabric

General a. Whether the house keeping is good? b. Whether all the first piece checking was done in time and reports submitted? c. Whether the inspected rolls were marked properly and delivered to warehouse? d. Whether the inspector has undergone checking for colour blindness and approved.

16.5

Normal problems in grey inspection

The normal problems in grey inspection are as follows: a. Disagreement between two inspectors regarding allocating penalty points. It is suggested to have periodic round tests, i.e., getting the same fabric inspected by different inspectors and making them to explain why they consider something as a defect and something as not defect. Let them come to one consensus. By this the difference of agreements shall reduce. b. Fatigue of inspection; inspectors cannot see certain defects. When same type of fabric is inspected for a long time, the eyes get fatigued and some of the defects cannot be seen. It is therefore necessary to give rest to the eyes for some time by asking the person to do other works like the entries, moving the fabrics, cleaning the area and so on. c. Demand for inspecting fast, whereas the defective points are more and inspection is getting delayed. When the defects are more, the time taken for inspection increases as each defect need to be marked, flagged and data entered in the system as well as in the books.

16.6

Dos and don’ts for fabric inspection

Understand clearly what are all the things that are supposed to be done without fail and what should not be done at any cost. Some examples are given below.

256

Handbook on Fabric Manufacture

16.6.1 Dos a. Take the design card and confirm that the design is same on the fabric. b. Get the priority for inspection from the incharge before starting the work. c. Clean the inspection table and the surrounding before start of the work. d. First check the back and face before going for full inspection. e. Ensure that the face of the fabric comes to the top on the inspection table while inspecting. f. Verify the length while inspecting the cloth by referring to length counter and compare with the length declared in the document. A tolerance of ± 1 metre is allowed. g. Stop pulling in the event you find any defect in the fabric. h. Inspect for visual defects with the light ‘on’ at a speed slow enough to find the defects. i. Enter the type and location of the defect in the report chart. j. Fabric width must be checked from selvedge to selvedge against standard. k. All defects must be flagged during inspection. l. Keep the rejected rollers at a specified place with suitable identification. m. Marking should be done at the end of the cloth by leaving the space of 5˝

16.6.2 Don’ts a. Do not allow any other person to remove or handle the fabric rolls. They may misplace them. b. Do not carry on your checking without confirming from your supervisor. c. Do not count the defects if the defects are too high. Inform the incharge and take his advice. d. Do not inspect the cloth if the light is not sufficient. e. Do not cut any fabric because of the defect. Discuss with incharge and follow the instruction. f. No penalty points are to be assigned to minor defects.



Grey fabric inspection

257

g. Do not assign more than 4 points to any defect. h. Do not inspect a fabric at higher speed.

16.7 Responsibilities of supervisor in grey inspection a. Arranging for inspection of fabric rolls after understanding the priorities and first piece checking. b. Ensuring good housekeeping in inspection area. c. Ensuring sufficient light is provided for inspection. d. Ensuring fatigue free inspection by rotating the jobs. e. Checking the labels on all inspected rolls and confirming them as correct. f. Ensuring correct entry of data in MIS and in other records.

16.8

Authorities of supervisor in grey inspection

a. Authorised to ask for re-inspection if there is any doubt in the test report. b. Authorised to stop inspection provided the table and glass are not clean. c. Authorised to refuse inspection if the fabric weight is differing from the standard weight. d. Authorised to refuse inspection if defects are too many. e. Authorised to report to HRD if any malpractice of manipulating the inspection reports is found.

17 Mending of Defects in Fabrics

17.1

What is mending?

Mending is an operation of correcting minor defects/faults, which are spoiling the appearance of the fabric. The faults are either removed by using a pincher or painted to make it not visible; the threads are realigned after removing a fault and finally the fabric is made acceptable to the customer. The faults are judged as mendable or non-mendable. The fabric is cut into short piece when a fault is non-mendable. The fabric defects such as slubs, smash, thick pick, floats, double picks, colour fluff contamination, missing pick and shaft hold are normally mended. The fabric defects such as yarn mix, defective selvedge, reed marks, reediness, weft bars, streakiness, temple abrasion, loose picks and loom stop marks are normally not mendable.

Figure 17.1 Shaft hold

Grey inspection is an important stage at which proper inspection should be carried out.The fabric construction, weight, structure, cotton quality and grades used, besides its other parameters like width, strength in grey, physical appearance like kitties, neps, manufacturing defects, piece lengths etc., are to be checked and cleared for processing as all these characteristics have their influence on the wet processing activity. The faults those can be mended at grey stage needs to be mended and then send to processing. A wrong decision at this stage can be disastrous, as any amount of intervention later cannot solve the problem. The 100% inspection is generally carried out to segregate



Mending of Defects in Fabrics

259

the products quality wise and perform mending activity for products having mendable defects. The main purpose of mending is to ensure that objectionable faults in the fabric are not passed on to end users. The fabrics made with fancy yarns or fancy designs and processes are high value adding, but are highly dangerous when fails in the market because of unacceptable quality. Hence, special care is to be taken while dealing with uncommon and fancy products. Any defect present in the fabrics/made-ups/garments, mars the general appearance and serviceability of the products. Hence, it is advisable to mend the mendable defects before further processing. A checker/mender should look into the following points before checking any type of products: 1. Any instruction from the buyer regarding non mending of specific flaws. 2. Defect appearing beyond the acceptable piece length should invariably be cut., e.g., if a buyer requires minimum piece length of 50 meters and a defect appears at 50.25 or 50.50 meters length then the piece should be cut just before the defect. 3. In case of fabric meant for garments/made-ups, defect on the selvedge or very close to the selvedge may be overlooked by the checker as these are eliminated during fabrication. In case of furnishing fabrics and made-ups with selvedge like shawls, sarees, towels, etc., selvedge defects cannot be overlooked. 4. Before checking/mending, the operative should take care that his hands, equipments used, checking table etc., are cleaned so that no handling stains are added to the product being checked. Mending cannot be done after weaving in certain fabrics like pure silk and closely woven fabrics, i.e., fine shirting etc.

17.2

Mendable and non-mendable defects

Defects are characterised as mendable or non-mendable depending upon the magnitude of the defect and the quality of the fabric. (e.g. double end throughout the length in denser fabric is non-mendable, whereas in loose woven fabric it is mendable). Mendable defects: Normal mendable defects include box marks, broken ends woven in a bunch, broken end, broken pick, colour flecks, coloured, oily or soiled ends, defective labels, double end, double pick, few stitches/snarls, fly or fluff contamination, grout, hole, knots, lashing-in, local distortion, loose or hanging threads, minor float, minor selvedge defects, misalignment of

260

Handbook on Fabric Manufacture

button and button holes, missing picks, oil or other stains, oily weft, sloughoff, slub, thick place, two ends missing at a place, two pick crack, defective hemming, shaft hold, size variation in towels (only on plus side) and weft loop. Non mendable defects: The defects normally not mendable are barre, big floats, big gouts, bleaching spot/uneven bleaching, blurred or dark patches, bowing of cloth, broken pattern, colour out, colour smear, crack of more than two picks, cutting defects, defect due to hanging threads, defective embellishment, defective selvedge, doctor’s stain, dye bar, dyestuff stain, embroidery defects, Hole/cut/tear, loom stop mark, loose picks, major selvedge defects, misprint or absence of print, more number of stitches/snarls, more than two missing/broken ends, patchy or streaky or uneven dying, pile less spot in towels, reed mark/reediness, shade variation, size variation (on minus side), slubby weft, smash, temple abrasion, uneven printing, weft bar, white spot and yarn mix.

Figure 17.2 Loose pick

17.3

Stages of mending

Mending is done at three different stages. They are in the grey stage, in dyeing and after finishing. 1. Mending in the grey fabric stage is done, where the loose and entangled yarns, bunches, big knots, smashes, are identified and removed. It is very important as any loose yarns, bunches of yarns etc., when present shall not allow the dye to penetrate in padding, and chances of getting white spec is there. 2. In the process house, mending stage is decided depending on the type of material and the style of dyeing being done. The stage of mending is as shown in the flow chart (Figure 17.3) in the dyeing, which depends on the type of fabric and the type of dyeing decided. 3. In the finishing mending, the faults like contaminations, thick neps, colour spots etc. are cleaned.



Mending of Defects in Fabrics

261

Figure 17.3 Mending in a fabric process house

Some of the tools used in mending are explained in figures 17.4 and 17.5. Thermo-bond patches: Thermo-bond patches are simple pre-cut patches supplied in different shapes and sizes, which can be used for mending small faults. A special glue layer on the back of the patch is heated under pressure which creates a firm fixation between both fabrics. Thermoplastic coating is produced by a unique technology, resulting in a very thin, smooth layer. Repair materials are supplied both on rolls and as pre-cut patches.

262

Handbook on Fabric Manufacture

Figure 17.4 Mending table

The mending operator checks the fabric and identifies the areas to be mended as marked by the checker. The mender discusses with the incharge in case some faults are non-mendable or the frequency of such faults are too many which may make mending unviable. In case the faults are too many and are non-mendable, the fabric shall be downgraded or offered to customer for approval. Only mendable faults will be mended.

17.4

Mending methods for woven fabrics

While discussing various methods adopted for mending woven fabrics, some aspects of garments are also discussed, as in some cases like bed sheets, towels, kerchiefs etc., the edges are stitched, and labels are put by weaver itself. Darning: Darning, also referred as reweaving is the repairing of damaged woven fabric. This is done with the use of a special hand tool. Either a new section of material is taken from a hidden area of the fabric and used for the repair, or replacement threads are directly woven into the damaged area. Care is taken to select the threads of same shade and depth. Once this new section is created then it is woven into the fabric that surrounds the damage area. The resulting repair, in most cases is not perceivable to the naked eye. The new section is woven into the fabric. The repair begins to appear seamless. Even with a fine weave, the result can be nearly perfect.



Mending of Defects in Fabrics

Mending scissors

263

Round-tipped needle In case of double ends or floats, the yarn is taken out by using round-tipped needle. Special needles are used to darn the damaged woven fabrics.

Pincher - Pinchers are used to remove thick slubs, contaminations or knots. Mending threads of varying shade and depth It is always suggested to take yarn from the fabric that is being mended. In case availability of the yarn from the same fabric is not there, or it is not sufficient, external threads can be used. This depends on the type and depth of damage on the fabric. Burling pens are the traditional artisanmedia of the cloth and garment industry used for mending faults in yarns and garments. Clothing factories use these products for retouching button-holes as well as repairing small faults in finished goods. They serve to eliminate small faults and stripes. It is advisable to sharpen the point to a spatula shape before use and then to begin with retouching. After retouching, spread Burling pens evenly with the palm or a piece of cloth to achieve a better transition to the adjacent area. Bondex tapes or thermopatch repair materials or similar materials for mending. These are special thermo-bonding tapes available in different designs and colours. One needs to select the tape nearest to the design and pattern. These tapes are used to mend small holes, torn portions of fabrics. The tape is kept aligning to the fabric design and then ironed. The hole or tear becomes invisible and fabric becomes washable. A basic sewing kit will have almost everything one needs to mend clothing. Depending on the types of fabrics and the normal mending works, the sewing kit shall be made ready.

Figure 17.5 Mending tools

264

Handbook on Fabric Manufacture

Figure 17.6 Thermo-bond patches

Weaving a new section using yarns of same count, shade and depth.

The new section is woven into the fabric.

Once this new section is created then it is woven into the fabric that surrounds the damage area.

The repair begins to appear seamless.

The resulting repair, should not be perceivable to the naked eye.

Even with a fine weave, the result can be nearly perfect.

Figure 17.7 Darning process

The possible causes and the method of mending some of the normal faults are explained below. Rips and tears: Rips and tears may be due to abrasion or sharp objects piercing. The mending technique used depends on whether it matters how much the mend shows, and whether the piece is worth spending much time on. For mending denim pants, children’s play clothes, everyday sheets and so on, the easiest and most effective method is making the repair with iron-on mending tape, or with the sewing machine’s straight or zigzag stitch. Most tears are



Mending of Defects in Fabrics

265

either straight or L-shaped, because they tend to follow the grain of the fabric. If the fabric is medium-weight or slightly heavier, use of mending tape is recommended. The mending procedure is as follows: 1. Cut a piece of tape about 1 inch wider and 1 inch longer than the tear, and round-off the corners. 2. Lay the piece to be mended on an ironing board so that the torn portion faces up, wrong side up. If it is hard to lay out the item making the edges of the tear stay together, make a large temporary patch of either fabric or heavy brown paper, and baste it lightly to the side of the fabric opposite the side where the mending tape will be attached. Be sure the basting threads are far enough from the tear so they would not be caught by the mending tape. 3. Lay the mending tape, adhesive side down, over the tear. Position it carefully; then use tailors’ chalk or a pencil to mark around it at several points. Take it off temporarily and preheat the torn area by ironing it briefly. 4. Replace the mending tape over the tear inside the markings. Iron it down according to the directions on the mending tape package; make sure the tape is completely bonded to the fabric. Let the patch cool completely before moving the mended item. If a basted fabric or paper holding patch is used, remove it when the item is completely cool. 5. Sometimes the edges of a tear cannot be brought together neatly because some of the fabric is missing or is so badly damaged it has to be cut away. When this happens, use iron-on or fabric patches, or hide the damage with decorative appliqués or patch pockets. Zigzag machine stitching is ideal for either patching or appliqué. 6. When a lightweight fabric needs mending like a torn curtain, iron-on tape is sometimes too stiff or heavy. For such light fabrics, hand or machine stitching makes a more flexible mend. 7. To repair a straight or L-shaped tear by machine, set the machine for a straight stitch, with about 10 to 12 stitches to the inch. Lay the piece under the presser foot so that the tear runs crosswise in front of you and the left-hand end of it is 1/2 inch to the right of the presser foot. Put the needle and the presser foot down on the fabric and sew in a zigzag pattern back and forth across the tear, switching the machine from forward to reverse and back again, pull the fabric gently with your left hand to keep it moving slowly from right to left under the presser foot. The mended tear should be held together by even zigzag rows of straight stitching, making a very strong but usually conspicuous mend.

266

Handbook on Fabric Manufacture

8. Where the mend can not be obvious, hand stitching can be made much less visible. Use a fine sewing needle (size 8 or 9) and fine thread; make tiny stitches back and forth across the tear. If the tear is very long or the fabric is difficult to hold, keep the edges in place while you work by basting the fabric to a piece of white tissue paper. Work back-and-forth rows of stitching through both fabric and tissue; sponge the tissue lightly to soften it, if necessary. Then carefully tear the paper away and remove the basting thread. Floats: Float is the improper interlacement of warp and weft threads over a certain area. The causes may be improper sizing (ends sticking) or broken end entangling with the other ends.Only minor floats can be rectified. The floating threads are cut with a clipper. Combing in both directions rectifies the resultant patch. Double end: Two or more ends getting woven as one is called as double end. This defect is characterised by a thick bar running parallel to the warp. This end, being twice or more the size of the regular ends, is the unwanted result of two bobbins of roving running in spinning in what commonly is referred to as doubling. Wrong drawing, taking more ends in heald eye are also the possible causes of double end. This fault can be corrected by pulling out the extra end with the help of needle. A bare patch is formed and can be filled by combing in both directions with the help of metallic comb. Missing end: The fabric is characterised by a gap, parallel to the warp. The number of ends missing may be one or more. The causes may be a) Loom not equipped with warp stop motion, b) Dirty drop wires or accumulation of lint may prevent their dropping and c) In electric warp stop motion, the electric bars are dirty or corroded.

Figure 17.8 Missing end



Mending of Defects in Fabrics

267

When there are only two adjacent ends missing, the fault can be rectified by combing in both directions using a metallic comb. This may fill the bare patch formed due to missing ends. Missing picks: The fabric is characterised by a gap, parallel to the weft. This might happen because of the weft stop-motion not detecting a broken weft. When there are only two adjacent picks missing, the fault can be rectified by combing in both directions using a metallic comb. This may fill the bare patch formed due to missing picks causing irregular weft density.

Figure 17.9 Missing Pick.

Double-pick: This is the result of one filling feed on a multi-feed shuttle-less weaving machine picking up the end from the reserve supply package and pulling in a double filling. This will continue to run until broken-pick is noticed. In plain woven fabrics, this defect materialises by the presence of two picks in the same shed for a part of the width of the fabric mainly because of sloughing-off. Remove the extra pick by using a needle and pincher, and then comb both the sides with a metal comb.

Figure 17.10 Slub

268

Handbook on Fabric Manufacture

Slub: Slub should be cut by thread clipper from both the sides carefully and cut portion should be removed by plucker. The resultant bare place can be rectified by combing with a metallic comb. Coloured flecks: Coloured portion should be carefully removed from the yarn by plucker if not possible, then follow the procedure as mending slub. If it is white polypropylene contamination in a dark colour dyed fabric, it can be removed by using a hot air gun with a pointed nozzle. It makes the polypropylene to melt and come out. Two ends missing at a place: Combing in both the direction by using metallic comb may rectify the bare place formed due to missing ends. Oil or other stain: These are spot defects of oil, rust, grease or other stains found in the fabric. Excess or improper oiling/greasing of looms and oil stained take-up roller are the main reasons for oily spots. Improper handling and storage of material in spinning department, oil-contaminated guides and oily hands during process of warping and improper handling of warp beams are also the reasons for oily warp ends. Weft package falling on oily ground, handling the weft with oily hands, weft carrying baskets having oil and dropping of oil on weft package during oiling of the winding machine are the possible reasons for oily weft. For mending, keep the stained portion of the fabric over an absorbent pad. Apply the stain remover and wet the stain and surrounding portion thoroughly. Rub gently to quicken the penetration of the stain remover. Rubbing should be done towards the centre of stain to avoid spreading. Note: Delicate fabric needs reduced pressure, otherwise defects like hole formation or displacement of the fabric will occur. Coloured, oiled or soiled ends, oily weft and oil or other stain: These defects can be removed by keeping the stained portion of the product over the absorbent pad. Apply the stain remover over the stain wetting it and the surrounding portion thoroughly. Rub gently to quicken the penetration of the stain remover and loosen the stain, rub immediately after application to avoid evaporation of the stain remover and partial drying up and rub while the stain is fully wet. If the stained portion gets partly dried, as in the case of a long stain, wet the dried portion again with water or stain remover for rubbing. Rubbing should be done towards the centre of the stain to reduce spreading. If the stain is hard, allow the stain remover to soften it before rubbing. Wipe out the loosened stain with a scoured or absorbent cloth or sponge soaked in water. If any traces remain, wipe again with the wet cloth. If still not removed, wet with more stain remover and rub and wipe as before. Change or wash the pad when it becomes dirty. The cleaned



Mending of Defects in Fabrics

269

wet portion can be allowed to be dried naturally or dry with an air jet if available. Spotting gun can also be used to remove the stain from the product. A spotting gun applies the stain remover and rubs and flushes out the stain. Precautions to be taken while using spotting gun, i.e., spray pressure and concentration of the jet of the spotting gun should be adjusted to suit the fabric weave or structure. Delicate fabrics need a reduced pressure, otherwise, hole formation, displacement or puckering of the fabric will result. Note: Grease stains are easy, which can be removed by the solvents like perchlorethylene, turpentine, gasoline, ether, acetone and alcohol. Sub Chapter 17.9 gives more details on removing stains. Minor float, stitches: The floating threads may be cut with clipper from both the ends. Combing in both the direction with the help of metallic comb may rectify the resultant bare place formed. One or two pick crack: Combing in both the directions with the help of metallic comb can cover the narrow bare streak. Care should be taken to avoid major local distortion.

Figure 17.11 Crack

Box marks: Only stained picks can be washed as oily weft. Injured weft cannot be mended. Gout/slough-off: The extra foreign matter/extra weft (bulk) yarn can be pulled out by means of needle and trim with the help of trimmer. Combing in both directions with the help of metallic comb can fill up the resultant bare place. Broken ends woven in a bunch: The broken end woven in a bunch can be removed by using plucker then resulting loose threads cut by trimmer. A bare pace occurring as a result can be filled up by combing in both directions by metallic comb.

270

Handbook on Fabric Manufacture

Figure 17.12 Broken ends woven in a bunch

Snarls: Snarls can be pulled by needle and the loops appeared on the surface of the fabric are to be clipped with the help of clipper. Local distortion: This defect can be corrected by combing in both the direction using metallic comb. Minor selvedge defect: Minor selvedge defect having less number of loops can be corrected by clipping with the help of clipper. Lashing-in: This defect can be corrected by pulling out extra pick from the selvedge end, which can be clipped with the help of a clipper. Combing in both the directions with the help of metallic comb can fill up the resultant bare place. Loose or hanging threads: These defects can be easily rectified with the help of clipper. Double ends: One extra end which can be pulled out with the help of a needle. The resultant loose end can be clipped with the help of clipper. A bare place if formed can also be filled up by combing in both the directions with the help of metallic comb. Size variation (on plus side): If the size is on the higher side than the acceptance limit, depending on the end use rework can be done to the required size.



Mending of Defects in Fabrics

271

Defective hemming: The defect can be normally eliminated by reworking the process of hemming partly or fully. Stitching defects: The defects depending on the nature and magnitude can be reworked to the requirements. Misalignment of button and button holes: These defects normally can be reworked and corrected depending on the extent of deviation. Defective labels: These defects can be reworked and eliminated depending on the extent of deviation/position.

17.5

Mending a sweater

Although this book is dealing with woven fabrics, the mending of sweaters is discussed here as it can help in mending embroidery defects, leno weaves and special fabrics. Repairing a sweater is a bit different from mending other types of clothing. Hand-knit sweaters and most sweaters made to look hand-knit can be mended when they’ve been badly frayed or snagged. Many good sweaters are even sold with a bobbin of yarn attached. Test for needle sizes by slipping needles into the existing stitches. The body is usually knitted on a needle that is a size or two larger than the cuffs.

Figure 17.13 Repairing sweater

Tools: yarn needle, straight knitting needles sized for the sweater cuffs or body, sharp scissors, crochet hook sized for the yarn.

272

Handbook on Fabric Manufacture

Materials: matching yarn of the same colour, weight, and type as that used for the sweater (acrylic, wool etc.). 1. When one thread in a sweater is snagged and broken, a horizontal tear opens between two rows of stitches. The tear can be rewoven in a stitch that looks almost like the original. Work with the right side of the sweater toward you, from the right end of the tear. With the point of a yarn needle, pick the two loose ends of broken yarn out far enough back to give you a length that can be tied to a new piece of yarn. Cut a piece of matching yarn about 1 foot long and tie one end of it to the loose end of the old yarn at the right end of the tear. Tie a small knot on the wrong side of the sweater, leaving 1½ inches of yarn on the end to be woven in on the wrong side after the repair is made. Thread the end of the new piece of yarn into the yarn needle. 2. Starting from the knot, bring the needle up through the first loop or stitch on the bottom edge of the tear, from the wrong side to the right side. Carry the needle across the opening and up through the opposite stitch on the top edge of the tear, from right side to wrong side. Bring the needle from the wrong side to the right side through the next stitch on the top of the tear, then down across to the first stitch on the bottom edge of the tear, from right side to wrong side, so there’s one up and one down strand in each loop. Continue forming a row of loops like the knitted stitches between the two rows of stitches that form the edges of the tear. After the last stitch at the left of the tear is woven, tie the end of the mending yarn to the loose end of the sweater yarn, on the wrong side of the sweater. With a crochet hook, weave the loose ends into stitches on the wrong side of the sweater. 3. If the neckband or the cuffs are frayed or torn (sometimes caused by binding-off too tightly) clip the stitching that holds the cuff or band seam, from the outside edge well past the cuff or band. Ensure not to cut into the knitting. Smooth the ribbed part flat and clip the yarn in the bind-off or cast-on row at its edge; pull the edge of the yarn to ravel the ribbing. Ravel the entire ribbed band, rolling the yarn as you go; tie broken ends of yarn together as you go. 4. With the ravelled edge and the right side of the ribbing toward you, pull the yarn to ravel it exactly to the right-hand end of the last row. With a straight knitting needle sized for the sweater cuffs, pick up the loose stitches from the left end, slipping the point of the needle into the right side of each stitch so that all stitches lie evenly in the same direction. 5. Reknit the cuff or neckband with the ravelled yarn, using the same ribbing pattern as the old cuff or band; when you come to a place



Mending of Defects in Fabrics

273

where the broken ends of yarn were tied together, bring the knot to the wrong side of the sweater as you reknit. Leave enough yarn to bind-off loosely so the edge of the ribbing does not break again; rebind carefully. The band will probably be two or three rows shorter than it originally was. 6. If the old yarn is too badly damaged to use, or if matching yarn of the same colour, weight, and type (acrylic, wool etc.) is readily available, reknit the cuff or neckband with new yarn, following the procedure above.

17.6 Typical procedure followed in a mill for mending The following procedure is normally followed while mending: 1. The fabric checker shall mark the mendable defects with washable colour, either by using a tailor’s chalk or a sketch pen. 2. The fabric after inspection is sent to mending section along with the job card. 3. The details are first entered in the stock register having columns of batch number, design number, user name and number of metres. 4. The respective heads of process house dealing with different materials or processes like Cotton, PC, PV and PW, or bleaching, dyeing, finishing etc., give the priority of their section referring to delivery schedules. 5. The incharge of mending allocates the skilled workers for different jobs of mending. 6. The mending operator checks the fabric and identifies the areas to be mended as marked by the checker. 7. The mender discusses with the incharge in case some faults are non-mendable or the frequency of such faults are too many which may make mending unviable. 8. In case the faults are too many and are non-mendable, the fabric shall be downgraded or offered to customer for approval. Only mendable faults will be mended. 9. In case of thick slubs, contaminations or knots, the operator uses a pincher and removes the defect. 10. In case of double ends or floats, the yarn is taken out by using round-tipped needle. 11. Special needles are used to darn the damaged woven fabrics. 12. After mending, a seal is put on the job card indicating that the fabric is mended.

274

Handbook on Fabric Manufacture

13. The materials mended are accounted against each mender’s name, and mending registers are maintained separately for cotton, PC, PV and PW. 14. The columns in the mending register are batch number, lot number, design number, user name, number of pieces, total metres in each piece, received date, mending date, mender and remarks. Signature of the person receiving the report at user department is taken. 15. In case the damages are very high, they are entered in the high damage register with the columns of batch number, design number, metres, and the type of damages seen. A sample is attached to indicate the type of faults and the signature is taken from the receiver of report in the user department. 16. Pre-finish mending entry book is prepared after completing the mending job and giving the report to the user department for the purposes of accounting and making payment to the menders.

17.7

Care for fancy and special fabrics

Special care is required to be taken while dealing with fabrics having fancy yarns and dyed for single component or cross dyed. Following procedure is an example: 1. Whenever a yarn is indented for special purposes, the production planning and control (P.P.C) shall indicate the quality requirement of the yarns with specific terms. 2. If single component dyeing or cross dyeing is adopted, the suppliers shall be informed that the yarns are going for single component dyeing, and yarns shall be specially prepared for that. No yarn shall be purchased from market which is in stock. 3. A technical team shall visit the yarn manufacturers and approve the spinner for the supply of yarn for special purposes and fancy yarns. No yarn shall be purchased from open market. 4. The supplier of yarn shall submit the test report of yarn, when ordered specifically for special purposes. 5. Sample yarns shall be dyed and swatches made to verify whether the yarn supplied is suitable for single component dyeing. 6. Marketing shall provide bench mark samples for deciding the acceptance levels for effects/defects to avoid over mending, over rejections and accepting of substandard materials. 7. If marketing is unable to provide a benchmarking fabric sample, the product design cell (PDC) shall prepare three samples from different grades of available yarns and send for approval.



Mending of Defects in Fabrics

275

8. The marketing shall discuss with the customer and get the approval from the customer. 9. The approved sample shall be kept as bench mark. The approved sample shall be cut and made three reference samples. One sample shall be kept in marketing, one with quality assurance and one with product development cell. 10. A library of master samples shall be made by taking the bench mark yarns and the bench mark fabric samples given by marketing are compared with that. The approved master sample shall be preserved for reference. 11. The fabrics produced in bulk shall be compared with the approved master sample. 12. In grey inspection, the loose and entangled yarns, bunches, big knots, smashes, are identified. The loose yarns are trimmed-off by using trimming scissors. 13. The checker shall mark on the grey fabric where mending is required. The grey fabric is mended at grey ware house as per the markings made by the checkers. 14. In process house, the fabrics are mended before mercerising after the vertical drying range drying. 15. In the intermediate fabric checking at process house, the checker shall verify the effects of mending to ensure that the mending is effective. 16. In the finished fabric inspection, the checker shall flag or put a sticker where mending is required.

17.8

Possible mending defects

Following are the possible mending defects: Defect description

Reason

Double end

During mending one extra end is not removed.

Double pick

During mending one extra pick is not removed.

Figure 17.14 Double pick Loops

During mending, after filling ends or picks, they are not properly relaxed.

276

Handbook on Fabric Manufacture

Defect description

Reason

Pin holes

During mending, if a knot on onside is relaxed unevenly, which is sheared in the shearing operation results as a pin hole after shrinking.

Figure 17.15 Pin hole

Un-mended

While mending, some defect misses the attention of mender. This normally happens if the checker has not marked the defect with a sticker or put a flag at the side of the fabric.

Tight pick

While mending, if pick is tightly filled and not relaxed properly.

Tails out

While mending if tails are not properly cut or trimmed and not interlaced in tuck-in.

Figure 17.16 Tails out Wrong mended

While mending if end or pick is not properly filled as per the weave and pattern, or if not relaxed properly after mending.

Pincher marks

Pincher marks shall appear if the end or pick is tightly relaxed creating abrasion while repairing. It can also happen because of using hard quality rubber or relaxing directly with metal surface.

Trailing picks

These are extra tuck-in length, more than 15 mm, which interlace in the fabric body, not pulled properly and cut during mending work.

Mending soil mark

If the grey fabric is directly put on floor or pushed from one place to another on a dusty floor we get soil marks. Wipe out the soil and dust periodically and do not keep fabric on floor.

Holes

Holes are formed mainly due to knots in yarn, accumulation of fluff or any sharp edges piercing in the fabric.

17.9 Methods for removal of stains from fabrics made out of natural fibres Kind of stain

Type of fabric

Procedure and removal

Acid

All

Neutralise with ammonia

Adhesive tape

All

Harden with ice cubes; rub-off with fingers, then apply perchlorethylene or other solvent.



Mending of Defects in Fabrics

277

Kind of stain

Type of fabric

Procedure and removal

Airplane glue

All

Apply acetone or nail polish remover followed by alcohol.

Alcoholic beverages

All

Soak in cold water immediately followed by white vinegar, then rinse with cold water.

Alkali

All

Neutralise with vinegar.

Blood

Cotton, Linen, Silk, Soak in cold water, then in dilute ammonia, wash Wool and sponge with cold water.

Butter

All

Sponge with perchlorethylene or other solvent.

Candle wax

All

Scrape away then sponge with perchlorethylene or other solvent.

Chewing gum

All

Apply ice, soak in cold water, sponge with perchlorethylene or other solvent.

Chocolate

Cotton, linen

Soak in cold water, wash with hypochlorite bleach.

Silk, wool

Soak in cold water, wash with hydrogen peroxide and then with water.

Cotton, linen,

Soak in cold water, wash.

Silk, wool

Soak in cold water, then in hydrogen peroxide. Wash again with water.

Cotton, linen,

Soak in cold water, wash.

Silk, wool

Soak in cold water, sponge with perchlorethylene or other solvent.

Fruit

All

In fresh, pour boiling water through stain, if stubborn, bleach with hypochlorite or hydrogen peroxide.

Grass

All

Sponge with alcohol, then with soap and water.

Ice cream

All

Sponge with perchlorethylene or other solvent.

Iodine

All

Soak in alcohol or boil in solution of sodium thisulphate (photographer’s hypo).

Ink (Fountain pen - writing)

Cotton, linen

If fresh, detergent and water, if dried, sponge with bleach, then sponge with oxalic acid, then wash, or put in sweet milk and let turn sour.

Silk, wool

Sponge with hydrogen peroxide, then with oxalic acid or skim milk.

Coffee

Egg

278

Handbook on Fabric Manufacture

Kind of stain

Type of fabric

Procedure and removal

Ink (ball-point)

All

Let stand 10 to 15 minutes in detergent lather, rinse. If stain remains, use petroleum jelly or sodium hydrosulphite, then sponge with perchlorethylene or other solvent. Some inks dissolve in glycerine followed by shampoo.

Iron rust

Cotton, linen

Sponge with oxalic acid, rinse well, or spread.

Lip stick

Cotton, linen

Rub with lard (a type of fat) until stain is soft, scrape-off grease wash in hot suds.

Silk, wool

Sponge with alcohol or perchlorethylene or other solvent.

Mildew

Cotton, linen

Sponge with hypochlorite bleach.

Milk or cream

All

Sponge with perchlorethylene or other solvent.

Mustard

Cotton, linen

Apply warm glycerine, wash with suds (foams) and hydrosulphite bleach.

Oil

All

Wash in soap and water or sponge with perchlorethylene or other solvent.

Paint

All

Wash in soap and water or sponge with perchlorethylene or other solvent on wrong side of stain (latex and acrylic paints wash out if not dried)

Perspiration

All

Sponge with peroxide and ammonia.

Rubber

All

Sponge with perchlorethylene or other solvent.

Rust

All

Sponge with lemon, vinegar or oxalic acid.

Shellac

All

Sponge with denatured alcohol.

Scorch

All

If light, dampen and place in sunlight or sponge with hydrogen peroxide.

Sugar

All

Sponge with hot water.

Tar

All

Moisten with perchlorethylene or other solvent, scrape-off, and then sponge residue with same solvent.

Tea

Cotton, linen

Soak in borax solution, rinse; or keep stain moist with lemon Juice, then expose to sun for day or two.

Urine

All

Sponge with soap and water or with salt solution, then apply dilute ammonia or hydrogen peroxide briefly and rinse.



Mending of Defects in Fabrics

279

Kind of stain

Type of fabric

Procedure and removal

Varnish

All

Sponge with equal parts alcohol and perchlorethylene or other solvent.

Petroleum jelly

All

Sponge fresh stains with perchlorethylene or other solvent, or so spread talcum. Let stand, then brush.

Water spot

Silk, wool

Hold in steam until damp, then iron

18 Final Inspection and packing of fabrics

18.1 Introduction The fabrics produced in a textile mill need to be packed as per customer’s requirements. The customer does not accept defective pieces, and hence they are not to be packed. The fabric needs inspection and mapping of defects. Depending on the type of defects and the distance between defects, decision shall be taken to cut the fabrics so that in fresh packed goods, there shall be no defects, and customers can be assured of it. It is termed as grading. After grading, it is packed as per customer’s requirement and dispatched to the given destination There is a difference between 4 point system and the final packing inspection. The 4 point system is used to verify whether the fabric can be accepted for further processes, whereas final packing inspection for ensuring that no defective piece goes to the customer. The activities in final inspection and packing are receiving the fabrics for inspection, inspecting and mapping the defects, preparing cut plan, cutting as per the cut plan, and finally packing either on rolls, book folding or thaan packing.

18.2 Receiving While receiving the fabric, one needs to ensure that the required fabric needed to be inspected is received and taken for inspection so that the results can be given in time and deliveries can be done in time. The priority for receiving and inspection shall be done as per the committed delivery dates. Following steps are to be followed while collecting fabric for inspection: 1. For inspection, if any priority is there, it shall be given to supervisor by department manager. 2. Supervisor is given special instructions, if any, by writing on job card. 3. The inspection operator takes instructions from the supervisor regarding the roll to be brought for inspection and specific points to be checked. 4. The concerned contractor or jobber hands over the horsy (special trolley for carrying finished fabric) to fabric inspector with job card.



Final Inspection and packing of fabrics

281

Figure 18.1 Horseback trolleys (horsey)

5. The design number and shade number shall be entered in the job card and shade card shall be given along with job card. 6. The machine and the surroundings are cleaned before taking the roll for mapping. 7. Job cards are tallied with given memo. 8. The following details are obtained: 1. Purchase order number, 2. Lot number / sort number / design no. 3. Roll number to be inspected. 4. Shade number. 9. The fabric cutting attached on all job-card is verified for design. 10. In case of piece dyed qualities, the shade card should be attached with job-card and verified. 11. The Job card is verified and ensured that Q.A. report is attached. 12. All horsey in the finishing department are verified against job card. All horsey are kept in the specified area waiting for inspection. 13. The required fabric is brought on horsey to the inspection area. 14. The details are entered in the fabric inspection register.

18.2.1

Dos and don’ts for receiving

Dos 1. Check for all the details in the Job card and special instructions before taking a fabric horsy for inspection. 2. Ensure shade card is attached to job card in case of piece dyed qualities.

282

Handbook on Fabric Manufacture

3. Ensure that fabric cutting is attached to all job cards 4. Ensure that Q.A. report is enclosed with the job card. Don’ts 1. Do not take any fabric for inspection unless the instructions are clear. 2. Do not accept a piece dyed fabric for inspection if the shade card is not attached to the job card. 3. Do not accept a job card if it is without fabric cutting. 4. Do not take a fabric for inspection and packing if the Q.A. report is not attached.

18.3

Mapping faults and cutting finished fabrics

The fabric inspector inspects the cloth and marks the defects as per their class. Supervisor in finish fabric cutting and packing area refers to mapping reports and understands the types of defects found and the distance between defects. He shall workout a feasible plan so that the loss to the company is less, while customers are assured of required quality. Supervisor shall prepare the cut plan and gives to the cutting operator. While preparing a cut plan, care is taken to ensure that the cut fabric is in multiples of lay length required for garments, and short lengths are avoided as much as possible. Very short lengths, those are not accepted by garment industry, viz., fents, rags and chindis are classified as follows: 5. Fents - Fabric cut pieces of length varying from 45 cm to 90 cm. 6. Rags - Fabric cut pieces of length 23 cm to 44 cm. 7. Chindis - Fabric cut pieces of less than 22 cm length. Thaan (थान) is a folded fabric in open width, ready for sale. The length shall be in multiples of a shirt length or a trouser length, and maximum length in a Thaan shall not exceed 12.5 metres. An example of cut plan is given in figure 18.2. The cutting machine operator shall check and mount the fabric on the machine with the help of the helper. Operator fixes a sticker on the fabric piece and also writes the details with chalk on both the ends of the fabric, and puts stamp on the ends of the fabric. Operator shall cut the fabric as per the plan given to him while verifying the actual place of fault. The cut pieces are grouped as per the grades, shade and pattern. They are wound on paper tube as per their grades. All good-cut pieces of same design/shade are wrapped on same paper tube, and on the last piece, sticker is fixed with the required details. For cutting the fabric, following steps are to be followed: 1. Supervisor refers to mapping report and understands the types of defects found and the distance between defects. He shall workout a



Final Inspection and packing of fabrics

283

Figure 18.2 Example of cut plan

2. 3. 4.

5.

feasible plan so that the loss to the company is less, while customers are assured of required quality. Supervisor shall prepare the cut plan and give to the cutting operator. The cutting machine operator shall check the trolley number and mount the fabric on the machine with the help of the helper. Operator fixes a sticker on the fabric piece and also writes the details with chalk on both the ends of the fabric, and puts stamp on the ends of the fabric. Operator shall cut the fabric as per the plan, but after verifying the actual place of fault.

284

Handbook on Fabric Manufacture

6. Cutter shall check the width of each piece and record.

Figure 18.3 Fabric inspection and roll cutting machine

7. The cut pieces are grouped as per the grades, shade and pattern. They are wound on paper tube as per their grades. 8. All good-cut pieces of same design/shade are wrapped on same paper tube, and on the last piece, sticker is fixed with the required details. 9. On each group cutting, the operator shall write metre, width, end piece number, and fix a sticker on last piece of design with details. 10. The cutting report shall have the details of the cutter no., lot no., date, shift, width, machine. 11. Before sending the material further, the length of grey fabric produced in that design is tallied with the lengths cut. If the length is not tallying, the report shall not be sent further unless all rolls are checked and the figures tallied. 12. The data is entered in the register and also the systems for management information system. 13. The cut rolls are sent for packing.

18.3.1

Dos and don’ts for cutting

Dos 1. Map the fabric well before taking decision for cutting. 2. Prepare a cut plan to have minimum loss to the company. 3. Check the trolley number before mounting the fabric on the inspection table. 4. Verify the actual place of fault before cutting, although you are given a cutting plan.



Final Inspection and packing of fabrics

285

5. Roll the fabric cut on paper tubes and keep in designated place with proper label. 6. Verify the details in the cutting report before sending it forward. Don’ts 1. Do not cut a fabric without cut plan. 2. Do not send the report if the length of grey fabric produced in that design is not tallied with the lengths cut.

18.4

Good cutting

There are different requirements of customer regarding the length of fabric they need for getting their dresses stitched. It depends on the type of garment they wish to get stitched like trousers, shirts, etc. The fabrics are inspected and then cut into specified length with a guarantee that there are no defects in that length and offered to customers as good length. The customer specifies the length requirement. Good cutting is the term used for cutting the good portions of the fabric into the required length for stitching garments, so that the buyer can directly purchase the cut pieces for stitching, for example, pant piece, shirt piece, blouse piece etc. The procedure normally followed for good cutting is as follows: 1. Mapping the defects as per procedure laid down. 2. Cutting the fabrics at the place of defects. 3. Collecting the short length fabrics that cannot go as rolls. 4. Separating the bottom weights (pant pieces) and shirting pieces. 5. Getting the details of exact length to be cut from the incharge of folding. 6. Cleaning the table before starting the cutting works. 7. Adjusting the manual folding frame ‘Warkata’ (वार् काटा) as per the length required. 8. Folding the small lengths of fabric using Warkata as per procedure laid out. 9. Cutting the pieces as per the specified piece length. 10. Checking the cut pieces and tallying with the length specified in the job card. 11. After checking, separating Fresh pieces B pieces, BB pieces, BBB pieces, fents, rags chindis.

286

Handbook on Fabric Manufacture Hand Folding – (Warkata) In case hand folded fabrics are required, the folder folds the fabric with the help of distance pins. By selecting the pins, the folder can get exact length for folding. This work involves skill of the operator. He has to fold the fabric with uniform tension. Any length can be adjusted as per the requirement of customers. For example, 1.2 metres for trouser length. Normally, 1 metre or 1 yard is preferred where the customer counts the number of folds to measure the length of fabric

Figure 18.4 Warkata वार (War) = Yard, कटा (Kata) = measuring scale

Note:

12. 13. 14. 15.

18.4.1

1. Fresh pieces → The pieces with full length as specified without any defect. 2. Fents → Fabric cut pieces of length varying from 45 cm to 90 cm. 3. Rags → Fabric cut pieces of length 23 cm to 44 cm. 4. Chindis → Fabric cut pieces of less than 22 cm length Packing assorted bales as per gradation. Packing 30 pieces in one bundle and all the bundles in one bale. Giving the packed bales for despatch. Entering the packing details in the systems.

Dos and don’ts for good cutting

Dos 1. Always select good pieces from the short length fabric rolls. 2. Get the details of length to be cut from the incharge as per the job card given. 3. Take help of Warkata for measuring exact length. Don’ts 1. Do not cut a big roll just for giving small lengths of good cut pieces, as price realised by good rolls are high.



Final Inspection and packing of fabrics

287

2. Do not cut the fabric as per your previous experience. 3. Do not use metal length measuring scale for measuring the length for cutting, as there might be human errors in holding the scale properly.

18.5

Book folding

Book folding is the term used for folding the fabrics in small book size so that they can be put in the show cases within the space available like books kept in a library. The size depends on where the fabrics are going to be showcased. Fabrics of a Thaan are wrapped on either a thick hard board or a wooden frame either by hand or by using a machine.

Figure 18.5 Book folding

The steps normally followed for book folding are as follows: (i) Get instructions from packing incharge regarding the fabrics that are to be book folded. (ii) Take the rolls from operator for book-folding after verifying the details. (iii) Clean the book folding table and surrounding area before starting the work.

288

Handbook on Fabric Manufacture

(iv) Open the fabric roll on table. Keep a clean fabric on plastic sheet to avoid stains. (v) Make double fold Warkata (double folding on hand folding frameवारकाटा) as per laid out procedure. (vi) Cut the fabric of the required length as per the despatch advice. (vii) Square up the fabric by aligning the selvedge while doing double folding. Do not worry if the cut edges do not match (Figure 18.6). (viii) Keep the hard board or the wooden frame exactly parallel to the edge cut and perpendicular to the selvedge (Figure 18.7). (ix) Fold the fabric on the hard board (Figure 18.8). (x) Continue folding the fabric around the board until you reach the end (Figure 18.9). (xi) Get confirmation from the supervisor whether to pin the end or to put a cello tape to prevent the fabric from getting unfolded (Figure 18.10).

Figure 18.6

Figure 18.7

Figure 18.8

Figure 18.9



Final Inspection and packing of fabrics

Figure 18.8

289

Figure 18.9

Figure 18.6 to 18.11 Steps in book folding

(xii) Make Thaan (थान ्) complete as mentioned in despatch advice for each piece and the total metres in the multiples of cut piece lengths (Figure 18.11). (xiii) Count the number of folds to confirm the number of cut pieces in each thaan. (xiv) Stack the thaan as per design. (xv) Pack fabric pieces as per grade viz. good cut, fents, rags, and chindis. (xvi) Hand over the packed materials to despatch with appropriate memo. (xvii) Enter the packing details in to the systems.

18.5.1

Dos and don’ts for book folding

Dos a. Get dimensions regarding the length and width to be folded for each book. b. Verify the dimensions of the wooden frame or hard board before taking them for folding. Don’ts a. Do not use the same standard for all customers while making book folding. b. Do not use a metal pin or clip without getting confirmation from the customer.

290

Handbook on Fabric Manufacture

18.6 Packing The purpose of packing is to ensure that the fabrics inspected and sorted out are packed in suitable bale form. The packing is carried out as per the guidelines given by marketing considering the requirements of customers and retail selling agents. The packing of rolls into bales are done as per the following steps. (i) The rolls after shade sorting are grouped as suggested in the sorting report. (ii) The sorted rolls shall be put in polythene bags and sealed with cello tape.

Figure 18.12 Putting sorted rolls in polythene bags

Figure 18.13 Fixing self-adhesive cello tape on the polythene

Figure 18.14 Shade sorted rolls waiting for packing

Figure 18.15 Rolls put in the HDPE bag, waiting for stitching

(iii) Packer shall check the batch number on roll sticker and verify with the inspection report. (iv) Number of rolls to be put in a bale is decided on the length of the rolls.



Final Inspection and packing of fabrics

291

(v) Data is fed in the system to generate barcode and barcode sticker is printed. (vi) The barcode sticker of piece number is fixed on roll after matching the metre and kachha (कच्चा) (temporary) roll number.

Figure 18.16 Pasting the barcode sticker

Figure 18.17 Barcode sticker

Figure 18.18 Inserting fabric rolls into HDPE bag

(vii) Bale marker will write down bale number at two places, design number, metre and number of pieces in bag. Wherever specified, the shade number is also written.

292

Handbook on Fabric Manufacture

Figure 18.19 Marking details on the bale

Figure 18.20 Weighing the bale The rolls as required are put in the bags by the helpers.

(viii) The Stitcher shall stitch the bags.

Figure 18.21 Stitcher stitching the bale

Figure 18.22 Noting down the details in register before entering into system

Figure 18.12 to 18.22 steps in packing

(ix) Bale marker marks on the inspection report after rolls are put in the bale. (x) The inspection report after marking is given to record keeping, where data is entered in the system.

18.6.1

Dos and don’ts for packing

Dos a. Check the batch number and roll number before taking for packing. b. Check the shade sorting report and group the rolls as per the report.



Final Inspection and packing of fabrics

293

c. Match the metres and kachha (temporary) roll number before pasting the barcode sticker. Don’ts a. Do not pack without verifying batch number. b. Do not pack without verifying shade sorting report. c. Do not put a barcode sticker without verifying metres and kachha (temporary) roll number.

19 Folding of fabrics

19.1

Purpose of folding

The folding is done to ensure that the materials are folded as per the need of the customers for easy transportation and storing. The folding may be either by hand or machine with single fold or double fold or on a roll. There are different requirements of customer regarding the type of folding they need. It depends on the type of storage facility they have, the culture of the people and the ease for handling. Folding is also done to make the fabric attractive and presentable.

19.2

Hand folding – warkata (वारकाटा)

A metal frame with number of pins fixed at predetermined length is used for the purpose of hand folding. One can select the pins depending on length needed in each fold, so that it is easy to cut. Normally 1 yard was very popular, and hence the frame is called as “warkata” in Hindi. War (वार) means yard and kata (काटा) means a measuring aid like a balance or stick. In case hand folded fabrics are required, the folder folds the fabric with the help of distance pins. By selecting the pins, the folder can get exact length for folding. This work involves skill of the operator. He has to fold the fabric with uniform tension. Pins at predetermined distances to set the folding width

Figure 19.1 Warkata frame



Folding of fabrics

295

Figure 19.2 Width setting for folding

Any length can be adjusted as per the requirement of customers. Normally 1 metre or 1 yard is preferred where the customer counts the number of folds to measure the length of fabric. 1.2 metres are asked specially for trouser material as normally one trouser length of an adult is 1.2 metres, and it shall be easy to cut and sell. Normally in hand folding, a worker folds 450 to 500 yards per hour depending on his capacity and the type of fabric.

19.3

Single folding machine

In single folding machine, the machine is adjusted to make folds of specified length; Normally 1 metre or 1 yard. Machine can operate at 50 strokes per minute. As 1 metre is set per stroke we can fold 50 metres per hour. However, depending on the length of fabric fed in each trolley, the time taken for set change shall vary.

Figure 19.3 Single folding machines

296

Handbook on Fabric Manufacture

The fabric is loaded in the back of the machine and taken up over the fabric tension rollers. The fabric is then taken through the swivel and clipped on the table. The machine is allowed to work. After 2 strokes, the length is checked and stroke is adjusted if needed.

19.4

Double folding machine

In double folding, the fabric is folded lengthwise by passing the fabrics on a “V” plate and then folded for a given length, a metre or a yard. Machines are available to make roll or book of double folded fabric.

Thaan folding

Figure 19.4 Single folding

Book folding Figure 19.5 Double folding

There are machines available that can be used for both single folding as well as double folding.

Figure 19.6 Double folding



Folding of fabrics

297

In case of machine folding, after folding the number of folds are counted, and at the same time the fabric is inspected. In hand folding, the folder himself counts the number of folds before removing the fabric from the stand.

19.5

Typical procedure for folding

Following steps are followed while folding a fabric: 1. The customer specifies the type of folding they need and marketing communicates this to the process house/folding section. 2. The head of concerned process advises the folding department regarding the folding requirements in writing. 3. The incharge of folding allots the works to different people by considering the stock of materials waiting for folding, the different types of fold required and the availability of men. 4. Before starting folding of a fabric, the concerned operator cleans the machine thoroughly by wiping with a cotton fabric. 5. In case of hand folding, the hooks are selected depending on the length of fold needed.

Figure 19.7 Selecting the hooks on warkata

6. For machine folding, load the fabric in the back with the help of a helper. 7. After three or four strokes, stop the machine and check whether the fold is coming properly. There should not be any creases or folds. 8. Adjust the tension if needed so that the fabric is folded without creases and fold, and at the same time, the selvedges are aligned. 9. Run the machine till the fabric lot fed is complete. 10. Remove the fabric from the folding machine and keep it on the counting table. 11. Check the fabric quality while counting.

298

Handbook on Fabric Manufacture

Figure 19.8 Loading fabric

Figure 19.9 Checking fabric quality

12. Count the number of folds and enter the number of meter of each piece in the fabric lot as per piece number in the production record, and enter the same in the system. 13. Verify the process house record of total length of fabric in each fabric lot and tally with the actual number of metres seen while folding. In case of major differences, inform the head of processing and arrange for searching the remaining rollers, and recheck the folded material. 14. Once the lengths are tallied, put the fabric stickers with details of Blend, fabric lot no., design no. and number of metres.

19.6

Control points and check points

It is essential to have clarity on the points to be controlled to achieve the targets and those to be checked to ensure the process in control. These points



Folding of fabrics

299

need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘control points and check points’ and display them in the work area so that the people on spot refer and follow.

19.6.1

Control points

a. Selection of suitable folding method for the material being folded and the customer’s requirement. b. Deciding on the length of fold for the fabric considering the purpose. c. Deciding and selection of process parameters, viz.: • Length of stroke. • Speed, i.e., strokes per minute. d. Deciding acceptance criteria for quality of folding of fabrics. e. Employing qualified and trained employees. f. Evolving production norms.

19.6.2

Check points

Material related a. The fabrics received against the folding plan received. b. The quantity of fabric received in metres. c. Type of fabric. Machine related a. The condition of the machine. b. The condition of the tension guides. Setting related a. The setting of stroke in yards or metres. b. In case of warkata, the distance between the pins selected. c. The speed, i.e., stroke per minute set. d. The tension set to keep the fabric straight without folds while feeding. Performance related a. Uniformity of folds throughout the fabric. b. The production achieved.

300

Handbook on Fabric Manufacture

Documentation related a. The design number, lot number and roll number of the fabric received for folding. b. Length of fabric folded. Work practice related a. Whether the machine was thoroughly cleaned before loading the material. b. Whether the speeds maintained are as per norms. c. Whether fabric was folded with uniform tension. Log book related a. Machines working b. Starting time of the running lots. c. Activities done and to be done. Management information system related a. Machine number b. Design number c. Roll number d. Type of fold e. Number of metres folded General a. Cleaning of the machine and its surroundings.

19.7

Dos and don’ts

Understand clearly what you are supposed to do without fail and what you should not do at any cost. Some examples are given below:

19.7.1 Dos a. Get the customer’s requirement for folding in writing from the head of processing. b. Verify the length folded after three or four strokes and ensure it as correct. c. Keep the folding area always clean and cover the fabrics in stock and the materials folded.



Folding of fabrics

301

19.7.2 Don’ts a. Do not accept oral instructions for packing, as you cannot take corrective actions after packing. b. Do not accept the folded fabric if the edges get folded and selvedges are not aligned. c. Do not allow more than 3 mm variation in 1 metre fold. d. Do not accept if the folding is not proper. Get it refolded. Selvedges should be aligned.

20 Fabric Sampling and Presentation

20.1

Presentation of samples

Samples are prepared and presented in the market to the customers to showcase the ability of the producer to produce different designs, styles and fabrics, and also to help customers to think and give more innovative suggestions to develop new varieties. The fabrics of similar category are grouped and presented in a manner that is appealing to the customer. The presentations may be done in different forms like hangers, booklet or cards as per the customer’s requirement so that the customer can show them to their customers and end users and book orders. A textile sample is generally a piece of cloth or fabric designed to represent a larger whole. A small sample, usually taken from existing fabric, is often called a swatch, whilst a larger sample, made as a trial to test production methods, is called a strike-off.  The use of swatches is an essential part of the design process as it enables designers to show the type of fabric to use, demonstrating how colours and different materials and trimmings will look in real terms before going to the trouble of making up a full design. They also offer the advantage of illustrating how colours and patterns will appear on an actual fabric, something that may not be readily apparent from a paper or digital design. The textile manufacturer might bring together many swatches of their materials into a single sample book, enabling a salesperson to show a wide selection of available designs in various colourways to potential customers without the necessity of having multiple rolls of fabric immediately to hand.  Sampling is a very important operation for sales promotion. Whatever designs are manufactured, some fabrics are taken out as samples and send to customers so that they can send the samples to their retailers and use as a base for selecting the fabrics and placing repeat orders. Depending on the availability of space, the retailers can display the samples effectively. There are three main categories of samples, viz., sample cards, booklets and hangers. Sample cards have very small sample of fabric with variations in shade from sample to sample indicating the possible shades in that design. The book samples have different samples bound as a book where the customer can have a feel of the fabric. Hangers are for displaying to get an idea about the design. Normally, a number of samples are hung together so as to get a feel of comparison.



20.2

Fabric Sampling and Presentation

303

Different types of sample presentation

Samples of fabrics can be presented in a number of ways. Following are some examples: a. Swatch cards: It may include surface mounted cards, sandwich cards, waterfall cards, pad cards, digital cards and presentation boards. b. Memo samples: It includes ticketed memo samples, back printed memo samples, labelled memo samples and chain memo samples. c. Hanging samples: It includes individual hanging samples, presentation hangers. d. Sample books: Sample books include stack books and waterfall books.

20.2.1

Swatch cards

Swatch cards are the most common way of presenting material samples. Designers and consumers prefer this to get a quick, convenient overview of what’s available in the materials catalogue. A typical swatch card is an 8½” x 11” panel that can be easily kept in a ring binder. Larger swatch cards can be made to fold to fit into a ring binder. Flip style boxes and cradles have become increasingly popular and make it possible to incorporate custom sizes. The variations in swatch cards include surface mounted cards, sandwich cards, waterfall cards, pad cards, digital cards and presentation boards. The quality of swatch card is as important as the quality of fabric being presented. If the swatch card is not good, it is not possible to impress the customer and sell the products. It needs the following: a. The right swatch in the right position on every card. b. Swatches that are straight, without stretching or lapping. c. Sharp, clean die cuts. d. Clean, crisp printing. e. No smudges, smears or glue residue. The swatch cards are also presented on-line through internet. The swatch card is scanned and put in the web, so that the customers can select the samples. Once the samples are selected, orders may be placed on-line, or else the customer may visit the supplier and see the sample personally and have complete feel of the fabric. 20.2.1.1

Surface mounted cards A surface mounted card is a swatch card that consists of a printed card stock with material swatches on one or both sides. These cards are the most

304

Handbook on Fabric Manufacture

Figure 20.1 Surface mounted cards

economical way of presenting material samples and work very well in a materials catalogue. Since surface mounted cards do not require expensive dies or complex tooling, they allow the greatest flexibility in design. 20.2.1.2

Sandwich cards A sandwich card is a swatch card with material swatches held between two plies of printed card stock. The swatches can be viewed and felt through die cut windows on the front and/or back of the card. Swatches are always straight-edge cut, and the visible portion of the swatch is determined by the size and shape of the die cut windows.

Figure 20.2 Sandwich card

Although sandwich cards are generally more expensive than surface mounted cards, they hold up better in use. Raveling and fraying of the edges are nearly non-existent.

20.2.1.3

Fabric Sampling and Presentation

305

Waterfall cards

On a waterfall card, the surface-mounted swatches partially overlap each other to offer a larger viewing area of the material. Waterfalls are also used to encourage the user to ‘feel’ the material.

Figure 20.3 Waterfall cards

The waterfall swatches can be straight edge cut or pinked, depending on the material. Standard size waterfall cards can be easily kept in a ring-binder materials catalogue. It is a very convenient way to show a larger number of material swatches without increasing the size of the card or using multiple cards. Waterfall swatches can be folded to highlight and accentuate the hand or softness of the material – great for velvets and other luxurious fabrics. Per swatch, waterfall cards are generally more expensive than sandwich and surface mounted cards, but they are less expensive when you consider the total area of viewable fabric. 20.2.1.4

Pad cards A pad card is a material swatch card consisting of one or more die cut framed swatches assembled into a card stock ‘case’ that can be put in a catalogue or ring binder. The swatches are identified on the die cut frame, which also adds dimensional stability. Pad swatches are usually pinked, but they can also be straight edge cut, depending on the material. They offer the largest viewing

Figure 20.4 Pad cards

306

Handbook on Fabric Manufacture

area possible in a catalogue-style presentation. For enhanced impact, the cards may include room scene images and other literature add-ons to showcase the materials in a typical use setting. The great advantage of pad cards is that they allow for smaller incremental releases of colour book offerings. This lets you avoid the significant investment of producing a large multi-book colouring set. 20.2.1.5

Digital cards

Instead of actual material swatches, a digital card contains digitally printed images of the materials which we want to show. The card can have a combination of digitally reproduced images and real material swatches to demonstrate hand and textural features of selected materials.

Figure 20.5 Digital cards

With digital swatching, one can show even the largest scale fabrics and materials in a catalogue. Fabrics with large pattern repeats, such as privacy curtains, can be scaled down to show the entire pattern sequence. Digital swatching is also a very cost-effective way to quickly produce a material’s sampling card because it eliminates the cost of the material as well as material handling and processing. 20.2.1.6 Presentation boards

A presentation board is essentially a large swatch card, usually constructed as a case-turned board with a swatched inside liner. Swatches are usually straight edge surface mounted, but can also be pinked or waterfalled. Since presentation boards are usually made in rather small quantities, sandwiching is rarely used. Presentation boards are often used by salespeople during the introduction of a new material to the market. As a result, these boards are generally sized to fit in a salesman’s portfolio with a closed size of around 12½″ × 17″ and an open size (two panels) of approximately 25″ × 17″.



Fabric Sampling and Presentation

307

Figure 20.6 Presentation boards

20.2.1.7 Sample cards

Sample cards contain different samples of very small size of the same shade with different depth of dyeing in a row so that the customer can select the fabric and shade as per his choice. A reference catalogue shall be given indicating the sample number so that customer can quote that number in the orders placed. On the cards, only the sample identification number is given without any other details.

Figure 20.7 Sample cards

Sample cards are given to regular customers, which they can keep in their office and refer while placing orders.

20.2.2 Memo samples A memo sample is an individual material sample used to confirm the designer’s or consumers’ initial material selection. Designers also use memo samples to present material recommendations to their clients.

308

Handbook on Fabric Manufacture

Figure 20.8 Memo samples

Memo samples are usually the final selection tool for the surface material and typically become the informal ‘contract’ specifying the material the end-consumer expects from their purchase. Memo swatches are generally larger than catalogue samples, such as swatch cards, stack books or swatch decks. The most common sizes for this type of sample are 8½″ × 8½″, 13″ × 13″ and 17″ × 17″. In memo samples, one large sized sample shall be attached on a card which contains all the details related to the samples. The details may be printed either on the back of the card or on the top or bottom in the face. This card shall be given to the fabric developers and also to inspectors, who may be internal auditors or final auditors. Memo samples, include ticketed memo samples, back printed memo samples, labelled memo samples, and chain memo samples. 20.2.2.1

Back printed memo samples

Back printed memo samples are used only on surface materials that can accept ink directly on their backing. This form of memo identification is mostly limited to wall coverings, which are either scrim, paper or spun backed.



Fabric Sampling and Presentation

309

Figure 20.9 Back printed memo samples

Back printing is an economical method when material characteristics and run quantity allow, since no additional material or attachment is required. Back printing is not feasible when the material does not readily accept lithographic inks, or when the quantity required is low. 20.2.2.2

Labelled memo sample Labelled memo samples are used when graphic continuity with back printed memos is wanted, but the quantity or material type does not allow for high quantity back printing. Labelled memos can be pinked, straight-edge cut, serged, or even paper-framed depending on the material.

Figure 20.10 Labelled memo sample

20.2.2.3

Chain memo samples

A chain memo sample or peg sample is generally just a smaller version of a memo sample. The sample itself is usually smaller than the fold-over ‘ticket’ used for identification. They usually come in a set, secured with a ball chain such as those used for key rings. Peg samples are usually placed individually on wall display pegs in showroom scenarios. Identifications can also be made with tickets that do not fold over. Sometimes they extend beyond one edge of

310

Handbook on Fabric Manufacture

Figure 20.11 Chain memo samples

the sample to provide branding identification visible from the face side of the material. Chain samples and peg samples can also be presented in a flip-style box or cradle. These boxes are fairly popular with design firms that have sufficient library sample storage. Some companies also use chain and peg samples as their memo samples. The smaller swatch size offers a cost savings relative to the larger memo sample.

20.2.3

Sample hangers

Sample hangers are kept on display in show rooms and marketing offices. The samples are relatively of larger size compared to samples presented in the sample cards.

Figure 20.12 Sample hangers



Fabric Sampling and Presentation

311

The hangers are normally made of card board and sometimes in plastic. It has a slot in the top so that it can be hanged on to a rod in the wardrobe or in a show case. Individual hanging samples are commonly used in retail or in a designer’s showroom. Hanging samples are typically large enough to allow the user the ability to drape, fold or hang the sample in a way that matches its intended use, such as covering an upholstery frame, or window. Presentation hangers can also be used to show suggested colour and pattern correlations, while still allowing sufficient swatch size to effectively show the pattern design. Hanging samples can be pinked or straight cut and serged. Serging is the most popular method, as these samples are subjected to a lot of use and handling. Hanging methods range from turned-edge cases with metal hanger units to plastic skirt hangers and fully incorporated die-cut cap units. Identifications can be applied directly to the incorporated hanger, or they can be attached to the swatch with a label or fold-over ticket. Sizes for individual hangers usually run 17″ × 17″ to 26″ × 26″ and are displayed folded to a size of 8½″ wide or 13″ wide by sample length. Because of the large amount of material per swatch, hanging samples usually call for a fairly limited distribution. With hangers, the customers get a complete feel of fabric, the patterns, which help them in taking a decision, whereas with sample cards, as the sample size is very small, complete idea of the fabric cannot be obtained. The hangers are easy to replace. The fabric is pinned with a stapler to the hanger. They can be arranged and rearranged depending on the theme and the occasion. 20.2.3.1

Individual hanging samples

Individual hanging samples are the most common form of sampling in the retail environment. They are bound into a hanger style cap and are usually identified with tickets, or ID cards.  The tickets can be applied to virtually any surface material, allowing for a consistent and contiguous graphic style. Individual hanging samples can be printed with multiple colours and can also include schematics and halftone imagery. This allows for the entire pattern repeat to be shown without the material costs of showing the entire repeat. Depending on the material, edges can be straight, pinked, framed or serged.

Figure 20.13 Individual hanging sample

312

Handbook on Fabric Manufacture

20.2.3.2. Presentation hangers

Presentation hangers are ideal selling tools when one wants to present a coordinated set of materials in a retail environment.  They are bound into a hanger style cap and are usually identified with identification strips or individual labels. Presentation hangers can have straight, pinked, framed and serged edges depending on the material being sampled. 20.2.3.3

Sample books

Sample books are made for taking different samples to the customers place and Figure 20.14 Presentation explaining the salient features. The samhangers ples are bigger compared to cards, but are smaller compared to hangers. In one book, number of samples can be fixed and is easy to carrying from place to place. In some show rooms, the books are also hanged so that the customer can open the book and see the samples without taking the samples out.

Figure 20.15 Sample books

Sample books are most often a permanently bound presentation. This allows for a more controlled presentation to the viewer, encouraging materials to be seen together. This permanence also means that the entire presentation is dependent on the timeliness and longevity of the entire collection of materials shown. With smaller swatch sizes and manufacturing processes more suited to large quantities, sample books are a good way to make the product viewable in more locations. Sample books include stack books, waterfall books and specialised books. 20.2.3.4

Stack books Stack books and stack pads are the common sample book used in the residential and hospitality markets. They consist of individual swatches stacked on top of each other and permanently bound into a turned-edge case.



Fabric Sampling and Presentation

313

Figure 20.16 Stack books

Swatches are often pinked, but they can be straight edge cut depending on the materials. Some fabrics require serging to limit fraying. Swatches are usually identified by a printed identification strip which runs along the bottom edge of the swatch back, or by a printed die-cut paper frame which covers all four edges of the swatch. Swatches can be stacked in one simple stack with all swatches having the same height and width, or they can be assembled in a vignette format. This allows large scale patterns to be viewed at the same time as their smaller scaled or solid colour coordinates. Stack books can be produced in many different sizes, depending mostly on the material being shown. The most versatile size shows a feature swatch of approx. 10″ wide × 8½″ high in combination with various half width and partial height swatches. Waterfall books A waterfall book consists of multiple individual swatches assembled together onto a page before final assembly into the turned-edge case. The swatches stair-step over each other on a single page, allowing all colours to be viewed

20.2.3.5

Figure 20.17 Waterfall books

314

Handbook on Fabric Manufacture

together. It allows the viewer to see several swatches at the same time, providing quicker access to their desired colour. Waterfall swatches can also be folded, which is a great way to present velvets and other fabrics that offer a rich, luxurious hand. Waterfall swatches are generally pinked, but can be straight edge cut; serging is also possible. 20.2.3.6

Specialised books

Specialised books are highly customised ways to present material samples. Sometimes the product is unique enough to warrant a little extra-special merchandising to get the attention it deserves. Special case constructions include textile covering, tip-in labels, sandwiched printed windows, a special handle, hot stamp foil decoration, decorative corners to give the book its own special look and so on. One can combine stack books with waterfall pages, swatch cards or even digital swatches. Special engineering may be required to show a specific repeat in the fabric swatch without incurring huge material waste.

Figure 20.18 Specialised books

20.3

Sample cutting machines

There are various types of sample cutting machines. Some commonly used machines are explained in this book.

20.3.1

Manual sample cutting machine

Different sample cutting machines are available for cutting samples in a presentable way, normally with zig-zag cutters. Manual cutters are used when the quantity available for preparing samples are very small, and the operator has to select some portion of the fabric manually and cut so that the sample has a pleasant look.



Fabric Sampling and Presentation Manual fabric sample cutting machine max. 45 x 45 cm SC 45-Hoza-Cutter -

315

Manual Sample Machinery » Brand ALMAC » MSCM

c.

Figure 20.19 Manual Sample cutting machines

Manual Sample Machinery - Brand ALMAC- MSCM has following features • The machine is used for cutting zig-zag swatches or samples of textiles. • The machine comes with 18″ with a blade; a maximum of 17.5″ × 17.5″ of samples can be cut conveniently. • The zig-zag serrated blade is re-sharpenable type, which gives a long life to blade. • Layers or piles of fabric up to 2″ or 50 mm can be cut at the same time. • The piled fabric is placed into a cutting board, which is placed on table on which cutting takes place. The blade is brought down for cutting by means of hand wheel. Once the blade touches the fabric, pushing a ratchet type hand lever does the cutting. • The hand wheel and hand lever movements are translated into movement of blade holder by gear mechanism. • These gears are machine cut to give a very high accuracy and ease of cut. • Two eccentric wheels connected to the blade holder allow immediate, constant and uniform cutting. • To ensure that accurate sizes of samples are cut, a scale has been provided on one side.

20.3.2

Motorised sample cutting machine

Motorised sample cutting machines are used when there are more samples to be cut, especially for hangers and books.

316

Handbook on Fabric Manufacture Sample Making Machinery » Brand ALMAC

ZEN Hoza-cutter- max 250 cm fabric sample cutting machine

‘PERFECT CUT’-Fabric sample cutting machine

Figure 20.20 Motorised samople cutting machines

Zen- Hoza sample cutting machines are manufactured in a cutting width from 30cm up to 165cm for serrated and 250cm for straight cuts. A manual model up to a fully automatic machine is possible. First one should check which sizes of samples are needed, in which thickness it has to be cut maximum (for books), which width is the fabric roll, whether there is a need to produce waterfall collections as well and how many samples are needed. After getting this information, the manufacturer can suggest the best model for the company. Brand ALMAC - MSCM has following features • The machine is fabricated from M.S. sheet metal structure and cross channels to give adequate rigidity and strength to the machine. • The machine is available in various sizes of 20″/24″/32″/36″ size serrated blade run by 2/3/5/5 H.P. 1400 R.P.M. 440 volts 50 Hz electric motor and suitable gearbox. • The zig-zag serrated blade is re-sharpenable type, which gives a long life to blade. • Layers or piles of fabric up to 2″ or 50 mm can be cut at the same time. • The machine has special safety device wherein it can be switched on with both the hand only thus ensuring that the operator hands are safe during the cutting operation.



Fabric Sampling and Presentation

317

• The cutting table has a scale which allows the operator to decide the size of cut conveniently and accurately. • Two cutting boards are provided with the machine that ensures that the blade does not get damaged during the cutting operation. • A wheel is provided to move the cutting board forward for the next cutting position. • Machine is mounted on vibration pads to allow minimum vibrations to pass through the machine during the cutting operation.

20.3.3

Waterfall sample cutting machine

Waterfall sampling machine is used when numbers of samples of different types are to be taken together. It presents the samples one after another in a continuous strip. The way in which the sample is coming out of the machine looks like a water fall as can be seen in the pictures below.

Waterfall sample mounting machine Labomat

Waterfall sample mounting machine KL II

Figure 20.21 Waterfall Sample cutting and mounting machines

20.3.4

Slitter – Rewinder

The Slitters are installed on fabric inspection machine, where the fabric is slit into 4 or 5 strips as per the need. The rewinding and slitting machines are

318

Handbook on Fabric Manufacture

manufactured upon customer´s request and can be supplied in different working methods. For example with Hoza cutter, It is possible to work with crush cut blades or ultrasonic cutting head, hot cutting also is possible sometimes. Also vertical or diagonal cutters can be installed.

Figure 20.22 Slitter – Rewinder

It is possible to manufacture modules to install into an existing machine., e.g., cloth inspection machine or behind a stenter frame. An edge cutting system is also a possible option.

20.4 Typical procedure followed for Sample preparation Following steps need to be followed while grouping fabric and preparing them for presenting to customers as samples: 1. Receiving fabric rolls from folding department in each design; for example, in cotton shirting 4.00Mtr, cotton bottom 3.00Mtr and in polyester suiting 3.00Mtr as per schedule. 2. Measuring rolls with warkata (hand folding frame) and scrutinizing the design in system. In case the design is correct, then taking it for next process in sampling. 3. Entering the design and metres in the stock sheet in records (excel) with the date of receiving the materials.

Figure 20.23 Ironing the sample



Fabric Sampling and Presentation

319

4. In each design of cotton shirting, cut 80cm samples, in cotton bottoms cut 50cm samples and in polyester suiting cut 2.00mtr samples, and prepare hanger, booklet and card as per marketing requirement. 5. Arrange the fabric on ironing table and iron it to remove the wrinkles and creases before taking it for cutting. 6. Make use of sample cutting machine to prepare hanger, booklet and card. 7. Use waterfall sampling machine when number of samples of different types are to be taken together. 8. Make use of multiple stapling machines for preparing hangers.

Single stapler is used while stapling number of small bits on to a card.

Multiple staplers in a row (4 staplers are fitted)

Figure 20.24 Staplers

9. Use manual cutting machine where the sample size is small and number of samples are few. 10. Prepare a hanger by keeping the fabric samples exactly in line with the card board hanger and staple it using multiple stapling machine.

Figure 20.25 Preparing a hanger

11. Prepare booklets by putting samples in the small booklet as shown in the figure 20.26

320

Handbook on Fabric Manufacture

Figure 20.26 Preparing booklet

12. Use Fabric punching machine for punching holes in fabric and preparing book let when specified by marketing.

Figure 20.27 Punching

13. Keep representative samples of the samples sent in a register for reference.

Figure 20.26 Sample register

14. Keep the remaining fabrics samples in LDPE bags in a design wise designated area. 15. Development samples and Yardage received in sampling section are forwarded to marketing after getting them checked by PDC, Customer Relations and QA.



Fabric Sampling and Presentation

321

16. The fabric is scrutinized at sampling folding section and then entered into their stock. 17. Dispatch details and rates are forwarded by the mail to concerned marketing person in HO, and the marketing advises the despatch section for despatching. 18. Entering the data of cutting and packing in software and making invoice and gate pass advice according to consignor and consignee.

20.5

Control points and check points

It is essential to have clarity on the points to be controlled in sample preparation and presentation to achieve the targets and those to be checked to ensure the process in control. These points need to be reviewed from time to time and modified to suit the requirements of individual companies and their targets. Each mill should prepare its own ‘control points and check points’ and display them in the work area so that the people refer and follow.

20.5.1

Control points

a. Deciding and selection of sample parameters, viz., type of card, number of samples in a card, sample dimensions, the sorts and designs, the samples to be presented in hangers and samples to be presented in book. b. Deciding the sample cutting machine to be used. c. Deciding on the background of the cards. d. Employing trained and skilled employees for preparing and presenting the samples.

20.5.2

Check points

Material related a. Whether the sorts and shades received are as per the marketing requirements. b. Whether the length of fabrics received for sampling is as per requirement. c. Whether the fabrics received are defect free or not. Machine related a. Whether the cutters and blades are in good condition in the sample cutting machines. b. Whether the condition of the machine is good and operates as per the programme set.

322

Handbook on Fabric Manufacture

Setting Related a. Whether the dimensions set is as required? Documentation Related a. The details of samples prepared and sent. b. The type wise samples prepared in each sort and design. Work Practice Related a. Whether the people are following steps as requirements all the time? b. Whether the machine and the surroundings are thoroughly cleaned after completing each sample? General a. Whether the men employed are adequately trained? b. Whether the consumption of sample boards, hangers, books etc., are as per plan?

20.6

Dos and Don’ts

20.6.1 Dos a. Receive sample fabrics roll from folding department by giving indent. b. Scrutinize design and metres of roll and then measure on Warkata c. Put samples of fabrics in group wise in lot. d. Hold the fabrics (sample and yardage) at the same distance from the light source and at same angle all the time for checking and viewing as you have done for the first work.

20.6.2 Don’ts a. Do not to accept fabrics in case design number is not written in the roll. b. Do not take to the sampling if length and design numbers are not matching. c. Do not put fabrics of other lots in samples. d. Do not change the distance and angle while checking the design for shade variation. If the distance and angles are changing, you will not get correct result.

21 Textile marketing

21.1

What is marketing?

Marketing involves a wide range of activities that involve both feeding customers’ views into the business and promoting products in order to drive sales. A marketing person will gain an in-depth understanding of what customers want by researching consumer markets and conducting customer satisfaction analysis. He will also need to create interests among the customers by building the brand and try to promote the products. Marketing is dynamic, exciting and often enjoyably stressful! One will need some retail experience and a good knowledge of the product and the market to enter this fiercely competitive field. Marketing is an ongoing process of planning and executing of the marketing mix (product, price, place and promotion) of products, services or ideas to create exchange between individuals and organisations. It is seen as a creative industry, which includes advertising, distribution and selling. It is also concerned with anticipating the customers’ future needs and wants, which are often discovered through market research. Essentially, marketing is the process of creating or directing an organisation to be successful in selling a product or service that people not only desire, but are willing to buy. Therefore good marketing must be able to create a “proposition” or set of benefits for the end customer that delivers value through products or services. Specialist areas in marketing include various activities like advertising and branding, communications, database marketing, direct marketing, event organisation, global marketing, international marketing, internet marketing, industrial marketing, market research, public relations, retailing, search engine marketing, marketing strategy, marketing plan and strategic management. Retail management and distribution management are two important aspects which either support or kill the marketing and merchandising functions.

21.2

Marketing strategies

Fluctuating customer requirements and competitive forces are putting more pressure on marketing and are demanding superior sales and marketing strategy and tactical execution. The cycle time from product creation to product launch for a winning go-to-market strategy, leaves no margin for error. The

324

Handbook on Fabric Manufacture

rapid commoditisation of complex solutions calls for summarising marketing strategy and timely execution, yet many companies are finding their sales and marketing strategies getting highly-diluted by the time they reach the customer. Marketing strategy is a process that can allow an organisation to concentrate its limited resources on the greatest opportunities to increase sales and achieve a sustainable competitive advantage. It is most effective when it is an integral component of corporate strategy, defining how the organisation will successfully engage customers, prospects, and competitors in the market arena. It is partially derived from broader corporate strategies, corporate missions, and corporate goals. As the customer constitutes the source of a company’s revenue, marketing strategy is closely linked with sales. A key component of marketing strategy is often to keep marketing in line with a company’s overarching mission statement. Marketing strategies are dynamic and interactive. They are partially planned and partially unplanned. A marketing plan contains a set of specific actions required to successfully implement a marketing strategy, which consists of a well thought out series of tactics to make a marketing plan more effective. Promotion involves disseminating information about a product, product line, brand, or company. It is one of the four key aspects of the marketing mix. The other three elements are product management, pricing, and distribution.

21.3

Competitive environment in marketing

The organisations operate in a competitive environment. The textile being manufactured world over and having innumerable manufacturers and sellers, the competition is very high. Analysing its competitors not only enables an organisation to identify its own strengths but also its own weaknesses, opportunities and threat to organisation from its environment. The following are the factors influencing the competitive environment. a. The manufacturing capabilities of the competing companies. b. The number of competitors. c. The technical edge the company is having. d. The rate of growth of industry. e. Availability of material in the market. f. Whether the product/service lacks differentiation or stitching costs. g. Switching costs and other fixed costs the buyers face in changing suppliers. h. The bargaining capacity of the customers, which again depends on the availability of material in the market.



Textile marketing

325

i. The ratio of fixed costs to variable costs. j. Whether the products or perishable. k. Normal expected life of the product. l. The negotiating capacity of the suppliers. m. The threat of substitute products and services. n. The policies of the governments. o. The culture of the community. p. The exit barriers if any. q. The versatility of the rivals and their strategies. All the above forces need to be used as a conceptual framework for identifying an organisation’s competitive strengths, weaknesses, threats and opportunities.

21.4

Sales management

Expanding business is not possible without increasing sales volumes, and effective sales management goal is to organise sales teamwork in such a manner that ensures a growing flow of regular customers and increasing amount of sales. There are four phases in management process, viz. conception, planning, execution and control. This model is cyclical and a constant/continuous process. Customers need products and service with customisation. In a number of cases it is seen that individual activity oriented approach becoming a barrier for sales to grow. The sales department must be organised, and sales people should specialise and co-operate with each other as well as other departments of the company. Poor team sales management leads to losing orders and customers. Therefore it is necessary to introduce a sales planning system. Estimated sales volumes should grow steadily from period to period despite the seasonal variations of demand because decreasing estimated sales volumes discourages sales managers. After setting sales goals, salespersons’ activities are planned by regions, clients, channels, managers, products, etc. Sales team leader or sales department head chooses volume and operational metrics to evaluate sales managers’ effectiveness and to motivate them from achieved result. Market potential and structure needs consideration while planning along with company’s strengths and weaknesses, customer relations history, etc. The sales manager needs to describe how he or she will execute assigned sales tasks to check his or her motivation to get things done. Sales tracking is an integral part of sales management. Without tracking sales tasks it is hard to find out if everything goes right and estimated

326

Handbook on Fabric Manufacture

intermediate results are achieved in time and in the limits of expected resources. If anything is out of expected range, one can analyse the details, talk to a sales manager responsible for this task and take corrective actions. The tracking of selling activities is to know whether the activities are actually leading to sales, which is a very difficult activity. Management must have a method of knowing if sales representatives are correctly engaging in enough of the right activities to produce revenue in the future. This leads to three key metrics: the right activities, the right way, the right amount. Sales tracking should allow sales team leaders to control sales tasks completion by using reminders and notifications, highlighting overdue tasks, analysing task history, etc. If the sales task management system is really great and duly implemented, the managements are well informed about all details of the company’s sales process in real time to know who does what, when, and how. The sales reporting includes the key performance indicators (KPI) of the sales force. The KPI indicate whether or not the sales process achieves the results as set forth in the sales planning and enables the sales managers to take corrective action in time in case the indicators deviate from the projected values. The sales reporting, in addition, is a source for motivating sales managers. It is made for internal use as well as for top management. If other divisions’ compensation plan depends on final results, it is needed to present results of sales department’s work to other departments. The sales reports are also required for investors, partners and government, so the sales management system should have advanced reporting capabilities to satisfy needs of different target audiences and help sales force to be more effective and make more sales.

21.4.1

Distribution channels

Distribution channels are required to assist the marketer to reach its target market. It is not practicable for manufacturer manufacturing in bulk to directly deal with end customers requiring one or two pieces at a time. The distribution channels include wholesalers, retailers, logistic supports, couriers, door to door delivery persons and so on. There may be a chain of intermediaries; each passing the product down the chain to the next organisation, before it finally reaches the consumer or end-user. This process is known as the ‘distribution chain’ or the ‘channel.’ Each of the elements in these chains will have their own specific needs, which the producer must take into account, along with those of the all-important end-user. A number of alternate ‘channels’ of distribution may be available: • Selling direct, such as via mail order, Internet and telephone sales. • Agent, who typically sells direct on behalf of the producer.



Textile marketing

327

• Distributor (also called wholesaler), who sells to retailers. • Retailer (also called dealer or reseller), who sells to end customers. • Advertisement typically used for consumption goods. Distribution channels can have a number of levels; the simplest level being of direct contact with no intermediaries involved known as the ‘zero-level’ channel. The next level, the ‘one-level’ channel, features just one intermediary; in consumer goods a retailer, for industrial goods a distributor. In small markets or in small countries it is practical to reach the whole market using just one and zero-level channels. In large markets or in larger countries a second level, a wholesaler for example, is mainly used to extend distribution to the large number of small, neighborhood retailers. In products like garments or finished fabrics for sale in retail market at rural or urban areas the chain of distribution is often complex and further levels are used. When choosing a distribution strategy a marketer must determine what value a channel member adds to the firm’s products. Customers assess a product’s value by looking at many factors including those that surround the product (i.e., augmented product). Several surrounding features can be directly influenced by channel members, such as customer service, delivery, and availability. Consequently, for the marketer selecting a channel partner involves a value analysis in the same way customers make purchase decisions. That is, the marketer must assess the benefits received from utilising a channel partner versus the cost incurred for using the services. Benefits offered by channel members are as follows: • Cost savings in specialisation – Members of the distribution channel are specialists in what they do and can often perform tasks better and at lower cost than companies who do not have distribution experience. • Reduce exchange time – Not only are channel members able to reduce distribution costs by being experienced at what they do, they often perform their job more rapidly resulting in faster product delivery. • Customers want to conveniently shop for variety – If you go to a textile show room, a customer shall see 20–30 fabrics or dress before selecting one. Hence a retailer needs to keep much more stock of garments or fabrics than what they can sell. • Resellers sell smaller quantities – Not only do resellers allow customers to purchase products from a variety of suppliers, they also allow customers to purchase in quantities that work for them. • Create sales – Resellers are at the front line when it comes to creating demand for the marketer’s product. In some cases resellers

328

Handbook on Fabric Manufacture

perform an active selling role using persuasive techniques to encourage customers to purchase a marketer’s product. In other cases they encourage sales of the product through their own advertising efforts and using other promotional means such as special product displays. • Offer financial support – Resellers often provide programs that enable customers to purchase products easily by offering financial programs that ease payment requirements. These programs include allowing customers to purchase on credit, purchase using a payment plan, delay the start of payments, and allowing trade-in or exchange options. • Provide information – Companies utilising resellers for selling their products depend on distributors to provide information that can help improve the product. High-level intermediaries may offer their suppliers real-time access to sales data including information showing how products are selling by such characteristics as geographic location, type of customer, and product location. The costs of utilising channel members are as follows: • Loss of revenue – Resellers are not likely to offer services to a marketer unless they see financial gain in doing so. They obtain payment for their services as either direct payment or by charging their customers more than what they paid the marketer for acquiring the product. Hence the manufacturer shall not get the full price what the end customers are paying in the market. • Loss of communication control – Marketers not only give up revenue when using resellers, they may also give up control of the message being conveyed to customers. If the reseller engages in communication activities, such as personal selling in order to get customers to purchase the product, the marketer is no longer controlling what is being said about the product. This can lead to miscommunication problems with customers, especially if the reseller embellishes the benefits the product provides to the customer. • Loss of product importance – Once a product is out of the marketer’s hands the importance of that product is left up to channel members. If there are pressing issues in the channel, such as transportation problems, or if a competitor is using promotional incentives in an effort to push their product through resellers, the marketer’s product may not get the attention the marketer feels it should receive. The distribution channel consists of many parties each seeking to meet their own business objectives. For the channel to work well, relationships between channel members must be strong with each member understanding



Textile marketing

329

and trusting others on whom they depend for product distribution to flow smoothly. For instance, a small garment retailer that purchases products from a wholesaler trusts the wholesaler to deliver required items on-time in order to meet customer demand, while the wholesaler counts on the retailer to place regular orders and to make on-time payments.

21.5

Textile marketing

When we talk of textile marketing, we may group them as per products like yarn marketing, grey fabric marketing, finished fabric marketing, garment marketing, etc. The marketing systems are not same for all products as the customer segments are different. Grey yarn is sold in bulk in big lots of 5000–25,000 kg to weaving or knitting industries, whereas dyed yarn lots are very small starting from even 1–200 kg or at the most 800 kg, depending on the shade requirement in that design. The grey fabrics are sold to big processing houses whereas the finished fabrics and garments are sold to retail shops. In retail shops, the fabrics or garments are sold to individual customers who take one piece in each variety at a time. The marketing strategies are different at different places. When sold in bulk, normally the sales are in credit basis, whereas in retail no credit can be given as tracing the customer is very difficult. Fabric marketing strategies are different compared to yarn marketing strategies. The yarns are sold to either weavers or knitters, whereas fabrics are sold to process houses in case of grey and to garment factories or retail cloth markets for making tailor made garments in case of finished. Normally fabrics are manufactured against orders excepting some regular sorts in plain weave that are piece dyed or printed depending on the demand. Some big companies, who have developed their brand image produce fabric in bulk with single design but sell at different markets especially for specific purposes like school uniforms, bed sheets, curtains, towels, upholstery, etc.

21.5.1

Marketing grey fabrics to process houses

A weaver can sell his grey fabric directly to a process house or a trader procures the grey fabrics and gets it processed on job work. The second type is more common not only in Indian market but in export also. Big trade houses purchase grey yarns from spinning mills of the required quality, give it on job work to small and medium weavers and get them processed in process houses of their choice and sell in their brand name at retail shops. The trader who gets the fabrics woven on job work normally pays on per pick basis irrespective of the width or weaves. He insists on fabric realisation

330

Handbook on Fabric Manufacture

for the quantity of yarn supplied to weaver on weight basis. An allowance of around 3% is allowed for the process wastes depending on the quality of yarn. If weaver produces less fabric than specified for the quantity of yarn given to him, he shall have to compensate for it. In case of yarns, the customer specifies the count, twist, strength, evenness, hairiness, and faults as the parameters to be controlled and delivered, whereas in case of fabrics the fabric width and density (G.S.M) are the main factors. In case of certain applications like carpets, filters, etc., the fabric thickness is given as a parameter to be controlled. The tolerance also depends on the application. In certain processes employing high speed coating, the width tolerance is on the plus side and there shall be no tolerance on minus side, as there are chances of fabrics coming out of chain and get folded if the width is lesser than the specified. In case the fabrics are going for garments, the tolerance shall be on both plus and minus side in the width as well as in GSM. For certain processes like weight reduction in polyester, the minimum GSM is very critical. The marketing person has to discuss with the processor and get the tolerances clearly and also the reason for it so that he can explain the same to the technician at fabric manufacturing. If marketing person is not capable of understanding the technical reasons told by the processor, he should take the technician from mill for discussing the technical parameters. While planning the loom activities, the weaver need to understand the process house requirements and limitations and accordingly plan the allocation of looms for different sorts. In case of export orders, weaver need to ensure that all the sorts in the particular order are completed within the specified date and the container is loaded full. If any sort is not complete, the container shall move out with less quantity and remaining materials have to be air freighted. The container shall not wait till the production and checking are complete. In case of local market, the materials can be transported as and when the sorts are complete by separate trucks and there is no need to wait for completing all the sorts in the order together as in the case of exports. However, there needs to be an understanding between purchaser and supplier so that maximum utilisation of the facilities at weaving as well as in process house can be made. In case the weaver and process house are in the same city or within a short distance, the mode of transport can also be agreed upon with mutual discussion, and make use of mini trucks, tractors trailers, three wheelers, bullock carts or even hand carts, whichever is convenient considering the infrastructure availability. Depending on the transportation facility and the distance travelled, the packing of fabrics can also be decided to have lowest possible cost with assurance of zero damage during transit.



21.5.2

Textile marketing

331

Marketing finished fabrics to garment industry

Garment industry procures finished fabrics for manufacturing garments. They specify the fabric width, fabric length, GSM, the pattern and design, the colour and shade, specific finishes like shrink proofing, flame retardant, anti-crease, etc., depending on the type of garments and their end use. Therefore we cannot sell fabric from stock. The requirement of garment industry is controlled by the fashion industry, which is very volatile. The requirements are changing very fast, and every time a new product is demanded, which need to be engineered as per the requirement of the market. The lead time accepted is very low as the fashion might change at any moment. Therefore garment industries normally identify certain weavers or knitters who have large capacity and are versatile in their product mix, and can divert their machines for this urgent requirements in a short notice. The order quantity is also very small in each design and the changeovers shall be very high, not only with fabric manufacturers but also with garment manufacturers. The success of a weaver or knitter depends on how fast he can change over from one product mix to another and deliver the goods within specified time. Of course, the companies charge premium price when the lead times are very low compared to normal, and such orders are termed as Green Channel Products. Buffer stocks can be kept only in grey yarns and sometimes in some variety of grey fabrics. All others have to be engineered as per the design requirement. The weaver and processer may need to procure certain materials, spares, chemicals and dyes specifically for a particular order, which also kills the time. Further, getting the shades and patterns approved from the customer also takes time. In spite of all, the fabric manufacturer is supposed to deliver the goods on specific date. Therefore, normally credit sales are not accepted. The lead time depends on the processes involved. In fashion items, the processes are not fixed, and each lot may be unique. Hence there is no standard process time as we can work out in spinning. When a fabric making factory or processing factory gets a large order and are not in a position to fulfil the deadline, they outsource from other unit. Either yarns are given out and fabric is got prepared or fabrics are given out, got processed and finished. Monitoring the quality and ensuring that both the units produce the same level of quality is more important as the difference within the order should not be visible to the customer. The marketing persons and design people at garment factories normally make trend analysis and compare from season to season and predict certain trends and forecast certain colours to get orders, and keep dyed yarn in buffer stock. Normally the bleached white yarns, and extra dark black and navy blue gets repeated orders, and people take risk in dyeing yarns in those shades and

332

Handbook on Fabric Manufacture

keep stock for 10–20 days, so that they dye other shades when the orders are confirmed. The fashion forecasters give an indication of likely colours for the season at different markets, and accordingly the dyes shall be procured and kept in stock.

21.5.3

Marketing finished fabrics in retail shops

The situation in retail shop is entirely different than supplying fabrics to garment units. In case of garment units, they are specifying the fabrics, whereas in retail, more varieties are needed. If a lady wants to purchase one set of dress material, she will see minimum 25 sets. Although men do not see so many alternatives, 5–10 is common. It means to sell one piece; we need to produce 20–25 pieces in different varieties. The retailers are not sure about the product being sold and hence normally purchase on credit basis, and the payment is made only for the materials sold, and remaining are returned back to the manufacturer. The manufacturer replenishes them with new varieties. The returned varieties are refinished and supplied to some other market. Retail selling is not easy. Unless the customer gets confidence in the shop, he shall not enter that shop. Studies done by Powerhouse Bizz.com show that 80% of retail clothing businesses fail within the first 5 years. Success in the retail clothing industry depends in large part to knowledge of retail operations, and the suitability of skills and personality to the business. This business requires that a retailer enjoy meeting people, be skilled in the art of maintaining customers, have a knack for choosing the clothes that people will actually buy, and possess a huge dose of fashion sense. The business may appear glamorous, but he must be willing to work long hours and be on his toes to adapt to every little change in the market. The industry is very competitive. Most retail stores, particularly small businesses, perish because of poor management, tough competition from department and discount stores and poor evaluation of fashion trends. Before embarking on this business, it is better to gain experience and expertise in the industry, even take training courses to give you the technical know-how of retailing. Following nine ways can help small business to succeed in the retail market: 1. Start small. One of the most common reasons for downfall of small retailers is that they tie up so much cash in inventory and overheads in the beginning. In case of short in cash, concentrating on getting select quality merchandise is suggested. As business grows and customers increase, one can then afford to increase inventory. Buying expensive fixtures at the start needs to be avoided.



Textile marketing

333

2. Learn about market. Before starting business, one should try to learn as much about the demographic of the area as possible. Whatever may be the area where business is being started, knowing the population characteristics of that area like their income, age, population brackets, etc., can assist in decision making process. 3. Maintain quality in merchandise mix. The success of clothing store will in large part depend on the right product mix. This depends on the store concept, finances, space, and the expected turnover rate. Selection of merchandise should be done carefully to meet market’s needs, and keep up with fashion trends. At the start of a business, it may be smart strategy to buy specific items from within several product lines. By offering a wider selection, one can protect self in case a line does not sell as expected. Always make sure that all the merchandise delivered are inspected thoroughly and are of acceptable quality. 4. Go heavy on service. When the unit is small, a retailer has to appeal to a relatively select group of people, and there are no chances of hundreds of customers in the shop at any one time. It is suggested to make an effort to know the customers by name, and even call big spenders when a shipment are got with merchandise just right for them. By this one can get advantage over the larger stores by the extra attention given to customers. 5. Plan and control inventory. In line with following a concept for store, consider the range within a reasonable structure. Selling everything from budget to very expensive is not a sound idea. Experts suggest keeping merchandise to within three prices lines (budget, off-price, moderate). A retailer needs to establish a system to know and maintain the inventory level. He needs to know on a daily basis what’s selling and how much, what are not selling so it can be marked down and the current market value of stock. The exact system to be chosen depends on the size of the store, type of clothing and competition. 6. Listening to customers. The success of clothing business will in large part depend on the selection of merchandise. However, it is best to always keep an open mind and be receptive to customer’s suggestions and accordingly arrange for the materials in the stores. 7. Cross market the products. The sales persons need to be encouraged to offer assistance and advice on accessories. They can also give suggestions to customer as what combination will suit them best among the choices available in the stores.

334

Handbook on Fabric Manufacture

8. Hire the right people. Hire employees who possess an understanding of the fashion needs of your target market. Depending on the product range marketed, the sales persons should be knowledgeable to explain the benefits to the customers, attract them and convince to purchase. 9. Market your store. Having a business in a busy market area may benefit from a lot of walk-in traffic. Still one must think of cost-effective strategies to advertise the business so that more customers know about the shop and the products offered. One of the very important activities of a marketing person is to ensure that the products manufactured are getting sold on a regular basis. He needs to go on continuously tracking the market potential, identify the potential customers, educate the customers on the merits of the products being sold and make the customer feel that the product being offered is useful for him/ her. In retail marketing, as there are numbers of varieties in stock, the promotional activity place a major part in making it success. A combination of activities for promoting the sales is referred as promotional mix. The parts of the promotional mix are advertising, personal selling, sales promotion, direct marketing and publicity/public relations. Media and non-media marketing communication are employed for a pre-determined, limited time to increase consumer demand, stimulate market demand or improve product availability. The four systems normally followed for improving the sales in a retail shop are as follows. 1. Advertising is a presentation and promotion of ideas, goods, or services by an identified sponsor. Examples: Print ads, radio, television, billboard, direct mail, brochures and catalogues, signs, in-store displays, posters, motion pictures, Web pages, banner ads, and emails. 2. Personal selling is a process of helping and persuading one or more prospects to purchase a good or service or to act on any idea through the use of an oral presentation. Examples: Sales presentations, sales meetings, sales training and incentive programme for intermediary salespeople, samples, and telemarketing. Can be face-to-face or via telephone. 3. Sales promotion is incentives designed to stimulate the purchase or sale of a product, usually in the short term. Examples: Coupons, sweepstakes, contests, product samples, rebates, tie-ins, self-liquidating premiums, trade shows, trade-ins, and exhibitions. 4. One excellent way to market any retail business is through networking. Networking can be done efficiently by becoming involved with customer community. Participating in local activities not only helps



Textile marketing

335

promote brand awareness, it can also leave a retailer feeling great for giving back to a supportive community. In a textile retail shop, it is not possible to store more volume of a single design as the customers are more interested in seeing varieties and select from them. As and when a fabric is sold, it should be replenished by another fabric of the same design. Hence the retail marketer should have a good logistic system by which he brings the material from his godown or gets from a networking partner. The show room should have more varieties and as and when a variety is sold, another should occupy that place. The shelf should not be kept empty for any reason as it gives a negative signal to the customers. Merchandising is the practice of making products in retail outlets available to consumers, primarily by stocking shelves and displays. While this used to be done exclusively by the stores’ employees, many retailers have found substantial savings in requiring it to be done by the manufacturer, vendor, or wholesaler that provides the products to the retail store. The manufacturer also feels that by arranging merchandising by them they can give more emphasis for their product, whereas a retail owner might not give importance to the manufacturer. While stocking shelves and building displays when the product is delivered, the manufacturer gets a clear idea of what is being sold and what is not. A supply chain or logistics network is the system of organisations, people, technology, activities, information and resources involved in moving a product or service from supplier to customer. For retailing to be successful, the supply chain should be strong.

21.5.4

Studying markets and booking orders for fabrics

In the fabric supply chain, a farmer can take risk of growing particular cotton, and somehow it can be sold; whereas a fabric manufacturer cannot weave a particular sort with a hope of someone purchasing it. When it comes to finished fabrics or garments, people cannot take risk of manufacturing and waiting for a customer, rather than they make analysis of the trends and identify the sorts and varieties those can be sold in a particular market and in a particular season. The market analysis considers the following factors. a. The type of consumers – Individuals or groups, their capacity to purchase. b. The purchase pattern or interests as per age group, religion, culture, and sex. c. Different seasons like summer, winter, monsoon or festivals, holidays, working days and their effect on the styles and fashions. d. Purpose for which the textiles are purchased. e. The market reaction for the sorts sold in last season.

336

Handbook on Fabric Manufacture

f. The competition in the area – number of competitors and products offered by them. g. The availability of products in the market and their ruling prices. h. Emerging trends in technology which can introduce new varieties. i. The changing cultures because of change in beliefs and values. j. The close observation of plans and movement of trend setters in fashion. Identifying trend setters and interacting with them is very important for predicting the market and future sale of fabrics. By analysing the changes taking place one can predict what range of styles can be sold and plan for materials, machinery and people. A good marketing person shall be able to discuss with the customers and convince them to book their orders in advance so that they should feel to be the first to get this new design or style. Forward booking helps the production and sourcing personnel to plan and do their activities effectively. While studying the markets, they need to be studied segment wise. What happens in one segment need not happen in another. For example the film industry can lead the fashion trends among youngsters whereas performance may be the key word in sportswear. If uniqueness is the requirement of an aristocrat segment, the uniformity might be the requirement in a social segment. The fabric producer should decide as to which segment he would like to cater rather than trying at all places. The economic changes influence the purchasing strategies of the customers. While the economy was poor, the people were concentrating on food and cloth as essential requirement, whereas with increased money power, their purchasing priorities are changing, and clothing is getting least importance compared to purchasing of mobiles, cars, PC, stocks and shares, real estate, etc., as people have enough clothes in their wardrobes. The increase in durability of clothing also has reduced the need for purchasing the clothes. The fabrics are now sold only during special occasions and not as a regular commodity as was in earlier days.

21.5.5

Handling orders

Once the order is received it is necessary to ensure that the customer’s requirements relating to the fabric quality like pattern and design, quantity, delivery schedule and special requirements if any are understood and communicated to the production people. It is normally done through Customer services section or production planning and control wing. It is necessary to ensure that the plant can produce and supply the fabrics to meet the customer requirements in time.



Textile marketing

337

The general process incorporates meeting the customers, understanding their needs, developing designs and patterns to meet customer needs, taking orders after approval of the samples and communicating to plant for manufacturing in bulk as per the customer requirement. The following is the procedure normally followed. 1. The potential customers are identified by referring to various mediums like regular customer/market visits, agents, advertisements, meeting various representatives at exhibitions and friends. 2. The customers are approached either in person or through phone or email to get the details of the product they want. 3. The customers are explained regarding the products the company offers. The presentation includes new product as well as existing product bases. 4. Fabric quality samples and some design hangers are sent to the customer for evaluation. At the same time the payment terms, basic prices and tentative delivery of products are communicated to the customer. 5. The marketing executives while sending the product to the customer showcases the innovative characterises of the product that the company offers. 6. The marketing executives get the details of yarn components, colour coverage, GSM, weave, ends and picks per inch and works out the cost. 7. In case customer provides samples for making then the same is collected for analysis and costing. 8. The above sample is handed over to the design representative for further analysis. The design representative fills the swatch analysis format. 9. Marketing executives discuss the price based on the cost sheet with the marketing HOD and quotes this. 10. The marketing executives making the costing shall keep the colour and depth %, manufacturing order quantity, shade wise run, the complicacy of construction and current yarn rates in mind before making the quote. 11. The marketing executive compares the price expectation of the customer with the company’s costing. If the price is found feasible then the sample preparation shall be taken. In case the price is found not feasible, the customer’s cutting and CAD are returned back to customer, normally within 48 hours with a proper covering note. 12. Upon finalisation of the prices, the customer sends his concepts/ swatches/CADs for either development to be submitted in a specific time frame or direct production.

338

Handbook on Fabric Manufacture

13. In case a development is to be proceeded a requisition is sent to plant’s product development cell and also updated in pending development status chart. 14. After preparing the development sample, the same are sent to marketing office by plant through design executive. 15. The development received by design executive are compared with original sample and then handed over to respective marketing executive and further sent to the customer for approval. 16. The feedback from the customer is collected and analysed. 17. Depending on sensitivity of the customer and magnitude of correction, either development is remade or decision is taken to go for direct production. The same shall be informed to customers. 18. The customer comments and the care expected to be taken at the bulk production is explained to the customer services at plant through manufacturing order as well as order approval sheet. 19. The sales contract/purchase indent is sent by email to the customer and asked for confirmation over mail. The customers may send their own purchase order against company’s sales contract or sign sales contract or confirm the same over email. 20. Once marketing freezes the order, manufacturing order is generated along with unique slot number and is sent to the plant production design cell/PPC (customer services) departments along with approved swatch cutting, quantity, delivery date, and any other important points related to particular order (order approval sheet). All the details are simultaneously fed into the system. 21. A hard copy of manufacturing order generated is sent by courier to factory. Also it is uploaded in the chart of pending for warping (PFW) by PPC which is exchanged between PPC at plant and marketing daily. 22. On receipt of manufacturing order at plant, the same is reviewed by PPC, PDC and technical heads for a final feasibility review. Any deviation and or acceptance are conveyed to marketing within 48 hours. 23. PPC wing of customer services gives the commitment for delivery by inputting the date in order status which is a part of PFW sheet and in case of any deviations the same shall be discussed with the customers if required. Each company may have their own systems and procedures, but essentially have to do all the activities stated above.

22 Customer Services

22.1

Importance of Customer Services

The success of an organization depends not only on the quality of products supplied at competitive prices, but also on the way the customers are kept satisfied. Sustained success is achieved when an organization attracts and retains the confidence of customers and other interested parties on whom it depends. Every aspect of customer interaction provides an opportunity to create more value for the customer. Understanding current and future needs of customers and other interested parties contributes to sustained success of an organization. In order to be successful in any business, it is needed to understand clearly the requirements of the customer, which is done by the customer contact person in marketing. The organization needs to take initiatives for determining the customer needs and not depend on customer to explain everything. The initiatives include meeting the customers directly and having one to one interaction, visiting trade fairs and exhibitions and observe the people and their choices, having surveys conducted of various markets and determining segment wise market requirements, interacting with other interested parties to understand additional requirements like cultural needs, societal needs, logics behind the needs expressed by the customers, the factors responsible for limiting the customers from procuring the materials. Understanding customer requirements is one part whereas reviewing ourselves whether we are capable of meeting customer requirement is another part, which is equally essential for getting customer satisfaction. Once an order is accepted, it must be fulfilled. If the organization is not in a position to meet certain requirements, they should tell the customers in clear terms instead of accepting the orders and not fulfilling it. The production planning and controlling wing of a mill has the responsibility of this aspect. The effective communications with customers is very important not only to get the orders, but also to sustain the business. The customer may ask for information relating to goods and services the organization is providing irrespective of whether that customer is interested in purchasing the same from the organization. They may make number of enquiries and the organization needs to reply so as to keep good relation and rapport with customers. The product development cell and the quality assurance personnel take the

340

Handbook on Fabric Manufacture

responsibility of interacting with the technical persons at the customer’s side and decide on the product parameters. The customers need information regarding the position of their orders, likely dates of delivery, quality level achieved, any deviations in the product compared to previous supply and any amendments in the systems adapted while manufacturing. The organization needs to furnish the information as needed. In number of progressive companies a dedicated person shall be allotted to each major customer, who is termed as customer custodian or customer nominated quality assurance person. The customers shall make remarks on the products and service as per their expectations. It may be an appreciation or a grievance. When a customer appreciates a product, it means that customer expects the quality to remain in that level and surpass. Anything inferior to that shall be considered as poor quality. When customer makes a negative comment about the product or service, it means that the organization needs to improve in that area. The organizations should proactively collect the customer’s feelings and act on that. There should be a mechanism to collect customer’s feedback proactively and not just trying to resolve a complaint by offering some discounts. Whenever an organization is handling customer property, on-line interaction with customer is essential to track the materials, quality and taking timely actions. A designated person should be there for each customer for interactions with the customer, and multiple reporting or multiple communications are to be avoided. The organization needs to proactively interact with the customers, discuss the specific issues and decide on the contingencies so that both can get benefit. The company should have planned arrangements for communicating with customer so that only required information are given to customers and avoid confusions or interpretations. Although all activities of a weaving mill should be customer focussed, the activities of product designing and development, production planning and control, quality assurance to the customer, customer contacts and communication are considered as Customer Service operations.

22.2

Product development

The design and development activities are normally done at two stages. The first stage is with customers and the second at the manufacturing area. The requirements are taken from customers and communicated to product development cell at mills, who shall develop a small sample by using miniature machines like single end sizing, sample warping and desk looms. Once the sample is approved, it is then developed on the normal production machines. Let us understand the procedures normally followed.



22.2.1

Customer Services

341

Design and development

Purpose: To understand the customer requirement and develop the fabric or design as per market requirement. Procedure: a. Receiving the fabric or design from marketing taking approval by chief of designing. b. Analysing the same and working out the reed, pick, weave, draft, peg plan, warp count, weft count, GSM and studying the shade and depth of dyed yarn components. c. Samples which are found feasible in terms of design, cost, and yarn range is chosen to make Handloom samples. Preference is given to yarn stock available in hand for developing the sample. d. Whatever samples are not to be developed immediately are kept in a file for future use. e. Rejected samples are discarded and retained samples are reviewed every year to ascertain whether to retain or discard them. f. Program for preparation of handloom sample are send by mail to sampling department at production plant. g. Records are maintained serially with the design request numbers in handloom sample file to track the sample development and reviewed daily to monitor status of sample. h. The samples are received from factory along with hand loom sample program card and marked in the handloom sample file for receipt. i. The samples shown to chief of design for checking the quality and matching with the original sample and then shown to the CEO and approval is taken for bulk production. j. Once the design is approved a quality instruction card is prepared and design number is allocated. k. Bulk production sample card is prepared for marketing purpose. l. The yarn requirement for bulk production is worked out and purchase order is issued to yarn purchase department. m. First piece cutting sample in A4 size received from plant for evaluation of the design is verified by the CED and is forwarded to marketing department for booking. n. After sample development the dyeing programme is issued as per marketing requirement.

342

Handbook on Fabric Manufacture

22.2.2

Single package yarn sizing

For developing samples the quantity of yarn required is very small, and hence regular warping and sizing machines cannot be used. Single end sizing machines are developed for that purpose. The procedure followed is normally as follows.

Figure 22.1 Single end sizing

(i) Get the details of the design number, shade number and count of the yarn to be sized. Weigh each yarn package and record them. (ii) Prepare stickers indicating design number, shade number and the count, and paste them inside the empty paper cone before putting the cone on the paper cone holder. (iii) Prepare a solution of 1.5% PVA (poly vinyl alcohol) as follows • Take 100 L of water in the stainless steel tank and heat it by using steam. • Take 1.5 kg of PVA in small bucket and pour little water and prepare paste. Ensure that there are no lumps. • Add this paste to the hot water tank slowly while stirring it. • Allow the PVA to get cooked, which normally takes 4 hours at 98 °C temperature.



Customer Services

343

• Keep the solution in hot condition, which can be used for next 12 hours. (iv) Set the winding machine parameters depending on the count. The speed depends mainly on count of yarn and the time taken for it to dry. Normally a lower speed is set for coarse yarns and higher speed for fine yarns. Speed is set by using a speed control knob. (v) The guidelines for speed is as follows Count Ne

Figure 22.2 Speed control knob

Speed in RPM

20s

10

30s

20

40s

25

50s

30

70s

40

(vi) Keep the package exactly below the yarn guide. Take the yarn through the ceramic eyelet Yarn guide with ceramic eyelet

Figure 22.3 Yarn path

(vii) Take the yarn through the tensions guides and discs as shown in Fig. 22.4

Figure 22.4 Tension guides

344

Handbook on Fabric Manufacture

(viii) Take the yarn through the sizing roller in the sow box and then through squeeze rollers. Yarn

Squeezing rollers

Sizing roller in sow box Size solution

Figure 22.5

(ix) After squeezing rollers, take the yarn to the dryer through entry guide.

Entry guide for dryer

Squeezing rollers Dryer Yarn

Figure 22.6

(x) Take the yarn over guide pulley for 1–3 rounds depending on the count and take it up to winding head (xi) Take the yarn through the sensor and then on to the drum, and finally on the paper cone fitted in the cone holder (xii) Fill the size solution in the size filling tank provided at the end of the machine. (xiii) Open the steam to keep the solution hot at required temperature.



Customer Services

345

Figure 22.7

Figure 22.8

Size filling tank

Figure 22.9

(xiv) Start the drums by pressing green button. Use red button for stopping the drum and yellow botton for attending to lappings on the drying chakra. (xv) Weigh the doffed cones and record the weights. Find the percent of size pick up. (xvi) In case the size pick is low or the yarn still looks weak, discuss with the supervisor and take for sizing again. (xvii) Enter the production data in the production record. (xviii) Deliver the sized yarns to warping and weaving in PDC production hall as per instructions of the supervisor.

346

Handbook on Fabric Manufacture

22.2.3 Developing warp sheet using single end warping machine Single end warping machine is a modified form of conventional warping machines, developed for sampling purposes, especially the ones utilizing coloured yarns or yarns of more than one count/type. The warping process is composed of several operations which wind up a limited thread length and place them on the warping width with several bands of different colours to get the colours variant of the fabric. In practice a cone per colour is sufficient to obtain any required warping sequence. This kind of warp can also be obtained by section warping, which however involves a considerable loss of time owing to frequent cone changes and definitely higher investment in raw materials. This system is used side by side with the traditional sectional warping machine.

Single end warping machine

Stationary Creel

Rotational Creel

Figure 22.10 Single end warping machine

The proper use of this machine permits to feed the weaving machine in a very short time while minimizing the use of materials and labour especially if an automatic drawing-in equipment is available upstream. Objectives of sample warping are • Preparation of samples for research. • To get the variant colours in the fabric. • Product from a limited amount of yarn. • To save time by working fast. • Reduction in labour cost. The machine consists of two parts namely creel and drum. The threads are pre wound on a drum before being wound on the weavers’ beam. Creel is the stand where the cones to be warped are placed. The warping plan is fed in the panel as per warping sequence. The yarns from cones are passed through accumulators, thread guides and arms which winds up a pre-set numbers of meters on the drum. The latest solution with revolving creel permits to winding speed of maximum 1200 m/min. Once the winding operation is concluded, the threads are beamed on a weaver’s beam which follows the



Customer Services

347

usual production cycle. The warp length that can be achieved in the latest model varies from 7 to 420 m. The use of creel depends upon the yarn sequence. Depending on the requirements of design, one can use either fixed, rotary or both creels simultaneously. Yarns, both in the fixed and rotary creel are accommodated in corresponding yarn selection guides, so that the yarns in the fixed creel and the yarns in the rotary creel can be used in combination in accordance with pre-set pattern data to wind the yarns on the warper drum to perform pattern warping. The fixed creel is used to perform pattern warping with a single yarn for complicated pattern warping, and the rotary creel to perform simultaneous plural yarn warping for plain warping or simple pattern warping. The rotary creel preferably comprises a base, a spindle shaft rotatable mounted to the base and protruding forward from the base. A number of bobbins are mounted on the spindle shaft through bobbin holders, and a guide plate mounted in a distal end portion of the spindle shaft through a guide arm so as to be positioned in front of the bobbins. The spindle shaft is rotated to wind the plurality of yarns simultaneously, supplied through the guide plate. Most preferably, the rotary creel comprises a yarn retainer attached to the front holder, and a guide plate and the yarn return unit are positioned in front of the yarn retainer, so that a plurality of yarns wound on the plurality of bobbins can be rotated and simultaneously supplied through the yarn retainer, the yarn return unit and the guide plate. Headstock is major portion of sample warping machine. It consists of a drum on which samples of yarn having different counts and colours are wound according to the desired pattern. Major parts and important features of parts of head stock are warping drum, automatic leasing device, yarn selector, push yarn device, loose yarn-preventing device, personal computer (with textile design software, stopping device for yarn breakage and beaming device. Warping drum is used to wind the patterned warp yarns. It has usually circumference of 7 m. Its working width is usually round about 2200 mm. Warp yarns are wound on it with speed ranging from 0 to 1000 m/min depending on yarn diameter, ends/cm and type of yarn. In sample warping, yarn is wound directly on a warper drum by a yarn winding means without using a conveyer belt to revolve the drum, so that various inconveniences due to the conventional conveyer belt can be entirely eliminated. A yarn winding means is mounted on a circumferential surface of the warper drum so as to be rotatable circumferentially. A yarn selector is provided in correspondence to the yarn winding means and movable in synchronism with the longitudinal movement of the yarn winding means. The yarn winding means is operable to directly wind at least one yarn, from a creel on which bobbins are supported, around the circumferential surface of the warper drum. The circumferential surface of the warper drum is defined by a plurality of drum spokes, each

348

Handbook on Fabric Manufacture

having at its base end an outer surface on which a pillow member having a taper surface slanting down to its tip is disposed, so that winding the yarn around the circumferential surface of the warper drum starts from the pillow members on the respective bases of the drum spokes and terminates at other ends of the drum spokes remote from the pillow members. The yarn winding means may include at least one yarn guide member attached to a drive belt or chain circumferentially rotatably mounted on the circumferential surface of the warper drum. When a yarn is wound, the yarn selector, the orderly winding guide means and the shedding means are intermittently or continuously moved with progress of the warping on the basis of warping yarn pitch. Thus, the yarn can be wound on the warper drum with windings of yarn neatly layered one on another in regular order. In case a single yarn is wound, the yarn pitch is: Yarn pitch , R =

Warping width Total number of yarns

When a plurality of yarns is wound, then yarn pitch is: Yarn pitch , RN =

Warping width × N Total number of yarns

where, N = Number of yarns to be simultaneously warped. The yarn selector transfers the yarn from the creel in accordance with previously input pattern data. The yarn winding means may be associated with the orderly winding guide means each having an orderly winding guide member, so that the yarn is successively wound neatly on the warper drum in regular order. It is preferable that the orderly winding guide member is longitudinally slid ably mounted on the warper drum. The control devices include • Belt shift speed control system for different yarn count. • Safety area sensors. • Pneumatic system to avoid slackness in yarn during switch over.  • Warp speed adjustment for individual end. • Automatic stopping on completion of set. • Auto safety stop. • Wound yarn aligning system. • Tensioning device to avoid loose yarn. • Automatic/manual beam alignment with warp sheet (beaming side). • State of art user friendly software.



Customer Services

349

• Simple data entry. • Remote access for feeding/monitoring and diagnosis. The beam taken out can be fed on Looms of normal size. The samples produced using such beams are normally referred as “Yardages”.

22.2.4

Developing desk loom samples

Desk looms are small looms which can be kept and operated on a table. This is used for producing small samples of 1–2 m length and 0.6 m width. A desk loom may be a hand driven loom or a power driven. Even rapier looms are available as desk top looms. The desk loom is used for comparing the colour and pattern from the original cuttings/samples.

Desk Looms Hand Operated

Desk loom Power driven CCI Evergreen Rapier looms

CCI Tech Sampling loom

Figure 22.11 Desk looms

The technical features of Evergreen rapier loom is as follows Model

Evergreen

Weaving width

20 inches (508 mm) maximum

Speed

75 ppm maximum (with reference to fabric width of 20 inches)/85 ppm maximum (with reference to fabric width of 10 inches)

Controller

PC based-industrial PC/Windows embedded operating system

Weft selector

8 colours electronic weft selection device

Fabric take-up

Electronically controlled. Weft density can be changed freely within the same weave.

350

Handbook on Fabric Manufacture

Model

Evergreen

Warp let-off

Positive electronically controlled. Digital display of warp tension. 
Optional second beam assembly available.

Shedding

Computerized controller. 20 heald frames driven pneumatically by air cylinders
 (1st & 2nd heald frames are for leno and selvedges). 
Optional up to maximum 24 heald frames.

Drawing-in

Heddle frames can be separated from the loom for heddles and reeds drawing-in.

Beat-up

Computer controlled driven independently by servo-motor. Suitable for heavy fabrics. Positions and quantity of beat up could be adjusted.

Weft insertion

Single rapier weft insertion driven by servo-motor. Speed could be controlled independently through the computer.
 Insertion can be adjusted for 10 or 20 inches.

Weft breaks

Equipped with weft-break detecting device. Loom stops when weft breaks.

Warp breaks

Optional warp stop device is available

Design Air consumption

880 L/min. Air pressure 6–9 kgf/cm2

Power

220 V Single phase, 50–60 Hz

The normal procedure followed in a mill for developing samples using a desk loom is as follows. (i) List all the request received on day to day basis for the development of desk loom samples (DLS). (ii) List the designs that are under development and those are completed. (iii) List out the designs pending in dyeing section. (iv) List out the dyed yarns received for the designs. (v) List out the yarns rewound after dyeing and kept ready for sizing. (vi) List out the designs sized ready and waiting for warping and completed warping. (vii) List out the designs warped and kept ready for drawing. (viii) List out the designs drawn and ready for weaving. (ix) List out number of beam falls. (x) List out number of DLS designs sent for processing.



Customer Services

351

(xi) (xii) (xiii) (xiv) (xv)

List out number of DLS designs received back from processing. List the number of designs checked and approved at despatch. List number of designs rejected and to be reworked. List number of designs despatched. List the men employed in each shift for different operations of DLS. (xvi) Review the report generated and take suitable action. (xvii) Discuss with the production personnel and the design people for visualising the problems likely to be faced in the event of design being accepted and orders received in bulk. (xviii) Enter the data in M.I.S.

22.2.5 Monitoring the designing activities of yardage Following procedure is normally followed for monitoring the activities of Yardage (20–200 m). (i) List all the manufacturing orders received on day to day basis for the development of yardage designs. (ii) List the designs that are under development and those are completed. (iii) List out the designs for which the lab dips are prepared, the lab dips approved and designs dyed, and the designs pending in dyeing section. (iv) List out the dyed yarn designs received at winding. (v) List out the yarns rewound after dyeing and kept ready for warping. (vi) List out machine wise information of the designs waiting for warping and completed warping. (vii) List out the designs sized and kept ready for drawing. (viii) List out the designs sent out for job works. (ix) List out the designs drawn and ready for weaving. (x) List out number of beam falls. (xi) List the greige designs received from job works. (xii) List out number of yardage designs sent for processing. (xiii) List out number of designs received from processing. (xiv) List out the number of designs checked by QA and approved. (xv) List the number of designs checked and forwarded to sampling section.

352

Handbook on Fabric Manufacture

(xvi) List number of designs rejected and to be reworked. (xvii) List number of designs despatched from sampling. (xviii) List the men employed in each shift for different operations of yardage. (xix) Record the productions in each operation in each shift machine wise and report. (xx) Review the report generated and take suitable action. (xxi) Discuss with the production personnel and the design people for visualising the problems likely to be faced in the event of design being accepted and orders received in bulk.

22.2.6

Designing activity for bulk designing

Following are the steps required to be followed while designing for bulk in order to develop workable designs. (i) Interact with PPC and get the manufacturing order (MO) details and the priorities of marketing. (ii) Discuss with the HOD and PPC regarding the priorities specified and clashes if any, and prepare final list of priority. (iii) Get the required details from MO as Slot No. customer, finish type, dye class, mercerised or non-mercerised, order quantity, overall count and construction, yarn dyed or piece dyed, blend, required finished width, any special comment received form marketing, required delivery date by the customer, quoted delivery date by PPC, order type viz. green channel, normal, or rework. (iv) Check the order type against DLS, YDGS, direct swatches, direct CAD, or as per design file (produced at HO or at customers end), old reference or repeat designs. (v) Workout the requirement of dyed yarns and the yarn to be dyed after verifying the shade wise stock of dyed yarns. (vi) Discuss the dye class required in case fresh dyeing is to be done and prepare requisition for lab dips and for generation of fresh shade number. Provide yarn skein/TPX or TCX No/CAD Chip/Overall CAD design/swatch as available along with the lab dip request. (vii) In case of MO against DLS or YDGS, pick up the data from DLS/ YDGS Master Card and issue the Bulk programme after cross checking all parameter of submitted DLS and YDGS, i.e., Count and construction, width, weave, pattern (warp and weft), and finish type.



Customer Services

353

(viii) If there is any deviation in actual submitted DLS and required Bulk then incorporate the changes. Find out if re DLS is to be made and then arrange for the same. (ix) Inform the concerned marketing person in case you find any change in parameter of submitted design and the requirement as per MO, and take approval. (x) In case of MO received against direct swatch/CAD, analyse all parameters of received swatch and calculate the required parameters in the bulk. Inform the marketing person and take approval in case you feel that there shall be some visible changes. (xi) For critical designs go through DLS route which was internally approved by QA, and if required despatch the design to marketing and get customer approval. (xii) In case of orders received make a reference of an old design supplied to customer, but with changes in count or shade, treat it as a new design and develop accordingly. (xiii) In case of receiving an MO needing only copying of old issued designs with some small changes done as quantity and customer, go through with the individual design with checklist for bulk production. Verify the swatch/CAD pattern and weave, the construction and the repeats, the count of constituent yarns, specific yarn quality to be taken for the same design, comments on colour placement and specific dye class specified of any shade. (xiv) Take seven copies of printout of master specification sheet and give one for design, two for PPC, one for dyeing, one for warping, one for first piece checker and one for QA. (xv) Attach three reference swatch and one set of yarn skein to the dyeing paper along with the master specification sheet with your signature. (xvi) In case of full width design, double cloth and random pattern make design in Excel. Take special care in case of special varieties like chambray, fila fill, top–bottom beam, seer sucker effect, cramming motion in weft, misdent or mispick effects, etc. (xvii) Before incorporating any specific comment which is mutually decided to do with the specific designs, check the points discussed in pre-production meeting, and write them on each design. (xviii) Check as per following technical checklist for design paper: a. Design No. b. Order No./Ref. No.

354

Handbook on Fabric Manufacture

c. Customer. d. Calculated count and construction against the required finish construction (EPI, PPI, width). e. Weave type and its repeat. f. Reed finalising. g. Denting order finalising. h. Warp and weft pattern – actual vs. taken. i. Warp pattern matching with drawing plan. j. Weft pattern matching with peg plan. k. Total number of ends matching with the warping section details. l. Count and Shade No. in warp and weft matching. m. Selvedge dents, its ends and weave. n. Warp and weft tape. o. Referred Shade Name Vs. Shade No. p. GSM/GLM. q. Dye Class. r. Mercerised or non-Mercerised. s. Finish type. t. Dyeing length, warping length, greige length and order length. u. Standard with design paper. (xix) After giving the design for bulk production, go to the loom and observe the problems if any. (xx) Make changes in design if needed after looking to working problems, while keeping the customer requirements intact. (xxi) Discuss with the production personnel, PPC and marketing people regarding the working and acceptance during the periodic meetings and get feedback.

22.2.7

First piece checking for design

Once the bulk sample loom is started the first piece needs to be checked in detail. The following procedure is normally followed. (i) Inform the weaver to takeout first piece of each design as and when the required metres are complete on loom. (ii) Check the design number, loom number, date and time of receiving the first piece before starting inspection.



Customer Services

355

(iii) Take design papers of each first piece from design file and enter the details of loom number and date. (iv) Check the parameters like ends per inch, pick per inch, warp pattern, weft pattern, repeat of design, colour and count match as per requirement, width of fabric and GSM. (v) In case any deviation is found in the fabric produced, take the help of quality control supervisor and the mechanic, and get the machine attended. (vi) Take sample again after correcting the loom and check for all parameters as mentioned earlier. (vii) Enter the following details in the register for checking the first piece, viz., Design No. of first piece sample, Loom No., Date, EPI, PPI and reed space on table, EPI, PPI and reed space on loom, GSM and GLM (weight in grams per linear metre) of first piece sample. (viii) Submit the report to senior designer and send the tested materials to grey godown for further action. (ix) Study the first piece report and decide the actions to be taken to ensure that the design and fabric meets the customer’s functional and aesthetic requirements.

22.2.8 Monitoring production hall of product development section The supervisor in product development cell needs to monitor the Production hall of the product development cell. Normally the following steps are followed. (i) Take round in the production hall and find out the designs being worked at various positions, and their status. (ii) Note down the designs likely to be completed in the shift and the designs waiting to be started. (iii) Check productions achieved in previous shift in each design and in each machine. (iv) Verify whether the productions achieved were normal or were there major deviations. (v) In case of major deviations, discuss with the previous shift supervisor and note down the reasons explained. (vi) Observe for the reasons explained and discuss with your superiors to overcome the problems.

356

Handbook on Fabric Manufacture

(vii) Verify the list of priority and allocate the machines suitable for those designs. (viii) Take round and verify whether the machines are set properly as per the design requirement. (ix) Verify the dyed yarn shade, lot number and count as per the label attached to yarn and confirm it as correct as per the design requirement. (x) In warping verify the warping speed, the beaming speed, the set length, the warp density set (ends per centimetre), total ends and the pattern. (xi) In the single end sizing machine check for the size recipe, the winding speed of each cone, the size pick up % and its uniformity, the weight in kilograms of each bobbin before and after sizing after drying. (xii) In weaving check the width on loom, the pattern against the design and peg plan, the ends and picks per inch on loom and on the fabric after doffing, warp sheet tension, the formation of selvedge, the fabric defects and fabric appearance. (xiii) Ensure that correct reed and healds are used as per the type of yarn, count and the density of weaving. (xiv) Check the working on loom and note down the breaks and the reason for breaks. (xv) Note down the time for stoppages and the reason for stoppages. (xvi) Provide temporary help in case of heavy works if any. (xvii) Record the readings of pick counter on hourly basis on all looms and investigate for low production wherever found.

22.3

Production planning and control

The basic activities in production planning and control shall be to prepare, communicate and monitor the production schedules, preparing monthly and quarterly production plans and reserving required yarns and following up with the production for completion of orders in time, and to coordinate with marketing in case of any delay.

22.3.1 Communicating and monitoring the production schedules Purpose of this activity is to communicate the customer’s specific order requirements suitably to production departments and help them to complete the



Customer Services

357

order in time by scheduling the activities and guide marketing by giving status of order on day to day basis. Following procedure is normally followed. 1. Marketing discusses with the customers and gets orders in different segments and sends the head of Customer Services (PPC). 2. The M.O.F shall be accompanied with cutting of fabric samples or C.A.D with details of shades. In case of repeated orders, there is no need of fabric samples; whereas a reference to design number or previous M.O.F is sufficient. 3. In case of orders received for direct selling of dyed yarns, e mail shall be sent to P.P.C (dyeing) from marketing, and no separate M.O.F shall be prepared. 4. The head of Customer Services calls for pre-production meeting on the day when manufacturing order is received. All the heads of the departments concerning production and quality and the unit head shall be present in the meeting. 5. The agenda for the pre-production meeting covers as follows. Agenda

Responsibility

Feasibility of Design

P.D.C., weaving, yarn dyeing

Quality parameters

Q.A., weaving

Delivery schedules

PPC, weaving

Other requirements

Team

6. The feasibility of the design shall be discussed and a consensus shall be arrived between P.D.C., weaving and yarn dyeing. It considers the criticality of the colour and design, the facilities available and the complexity involved in the operations. Marketing shall be informed regarding the feasibility and what can be offered. 7. The quality parameters include understanding of the type of yarn required, the quality parameters of the yarns to be specified, precautions to be taken while manufacturing and the quality checks to be carried out while the lot is working. 8. The delivery schedule is worked out by considering the number of machines available, the specific features of the machines, the normal efficiency, reed availability, vessel loading and the problems expected. 9. In case it is felt that the delivery schedule given in the M.O.F is not possible under the prevailing circumstances, the possible date of

358

10.

11.

12.

13.

14. 15. 16.

17.

18. 19. 20. 21.

Handbook on Fabric Manufacture

delivery shall be worked out and marketing is informed by suitable means like sending e mail. If the revised dates are not suitable to customer the marketing shall inform Customer Services. If marketing does not make any reply within a week, it shall be assumed that the revised dates given by Customer Services are agreeable to customer, and Customer Services shall proceed further for manufacturing the fabric. Among the other requirements, the modifications to be done on the machines, the procurement of reed, etc., shall be discussed. The head of weaving shall workout the specific loom requirements like reed and sends indent for procuring it, either on a permanent basis or on loan. The production planning shall indent for the yarn giving the required date of the materials. In case the design is critical or the order is of repeated type, the mill from which the yarn is to be procured shall also be indicated. In case any special yarn is required, the lead time for yarn procurement shall be studied with yarn purchase and the delivery dates shall be worked out. The P.D.C and Q.A shall refer to the quality reports and specify the supplier in case special yarns are to be procured. The product development cell (P.D.C) shall workout the design card for all the fabrics mentioned and submits to Customer Services. Production planning shall workout the dyeing orders including the direct sales of dyed yarn, and workout combinations to balance the machine availability. They consider the machines loaded and the vessel capacity available. Once the yarn is received, the yarn godown informs the quality assurance, who in turn checks the yarn quality and submits the test report. Once the yarn is approved, on-line instructions are given to yarn dyeing by Customer Services. Production planning and control gives day to day yarn dyeing plan to dyeing section. Yarn dyeing gives their yarn requirements to weaving preparatory which shall draw the required yarn from yarn godown. The number of drums to be allotted for various activities of winding, the warping machine to be worked and the sizing machine to



Customer Services

22.

23. 24. 25.

359

be worked are decided by the in-charges of respective weaving preparation. Customer Services suggest the type of loom to be worked whereas the head of weaving decides on the particular loom to be run for the given M.O.F. Once the weaving is over, the grey fabrics are inspected and sent to grey ware house. Once the fabric is arrived at grey house, the PPC wing of Customer Services sends job card to processing. Customer Services shall follow up the production up to packing and send status report to marketing on-line on daily basis.

22.3.2 Preparing monthly and quarterly production plans and reserving required yarns Purpose of preparing monthly and quarterly production plans is to plan the monthly and quarterly activities considering the orders in hand and the trends in the market so that the production infrastructure and the raw material procurement can be planned and kept in place. Following steps are normally followed. 1. Marketing discusses with the customers and gets a feel of market for different products and educates Customer Services on regular basis. 2. Respective heads of marketing shall prepare projected plans for 3 months, 6 months and annual basis and inform the mills so that the mills can plan the infrastructure requirements. 3. The production planning and control shall study the broad plan given by marketing and tally with the orders in hand. 4. The marketing shall workout tentative plans, without considering the actual designs, but considering the yarn that may be required. 5. By considering the orders in hand, the plans given by marketing and the trends in the previous twelve months regarding the consumption of yarns of different counts in different seasons, production planning and control shall make projections that can help the yarn sourcing to book orders for the yarn. 6. The projections made shall be discussed with the marketing and sourcing teams. 7. The yarn sourcing shall identify the reliable yarn suppliers in terms of quality and timely delivery, and book orders with them for specified

360

Handbook on Fabric Manufacture

count on 6 months basis, with a request of flexible delivery schedule that helps the supplier to spin all yarns needed with a single mixing, and assured of business.

22.3.3

Production planning and control activity

The normal procedure followed in production planning and control activities are as follows. a. Marketing requirements are received via indent in 2 copies containing design and meters to be made. One indent copy shall be sent back to the marketing after writing delivery schedule on it. b. As per the booking of the goods by marketing department and receipt of indents the production program shall be reviewed and the target dates revised and modified based on the urgencies, machine capacities and availability of yarn and looms. c. Production requirements are received from the design team, which are approved by the chief executive, along with the yarn calculations. d. Based on the above, tentative production program is provided to the plant for both piece dyed and fibre dyed. e. Yarn requirements are prepared based on the orders received and the yarn stock available and entered into the system at Head Office for procuring. f. In case yarn is not available yarn requisition is provided to yarn purchase department along with expected delivery date. g. Feedbacks are received from yarn purchase section regarding yarn availability and expected delivery and discussed with marketing regarding the delivery schedules based on yarn availability. h. Based on agreement with marketing the yarn booking is confirmed as well as the production program based on the yarn position. i. In case of any yarn issues, coordination is done with the yarn purchase department for resolution of the same. j. Plant capacity and machine capacity are checked before making the planning. k. Production program shall be prepared and 2 copies generated; one is sent to plant and second is kept as office copy. l. For each design based on the indent a separate production program is issued. It should be ensured to mention the correct quantity and delivery date as per the marketing requirements. m. Follow up is made with the plant regarding the status of the production programme from yarn – preparatory – loom – grey and dispatch.



Customer Services

361

n. The loom status, utilization and efficiency for all looms are monitored during running. o. Coordination is done with plant regarding quality problems based on first piece inspection report and discussed with them for any issues and possible solutions. p. After completion of the grey fabric communication is made with plant, and coordinated for priorities and ensured dispatch to process house. q. The stocks for grey fabric are monitored at the plant to ensure movement of old stock more than 30 days.

22.4

Quality assurance

The activities of quality assurance includes testing and approving of all the materials received, checking the processes and ensuring that they are being followed and testing the materials produced to ensure that the quality is achieved and only acceptable quality materials are sent to customer. The testing of incoming materials include testing of yarns, testing of colours and chemicals. The procedures adapted are as per the approved norms and the established practice in the industry. The process monitoring system is designed by each mill depending on the machines and the products. The outgoing material testing is done as per the customer’s requirements.

22.4.1

Yarn approval

Purpose of yarn testing is to make sure that the yarn meets the specified requirements for fabric to be woven, and to make sure that the fabric made out of the yarn meets the specified standard. The performance of weaving and the quality of the fabric produced depend to a great extent on the quality of yarn being used. It is therefore essential to check the yarn from different angles and verify whether it is suitable for the purpose. The method used for testing is as follows. 1. Incharge of yarn godown informs about yarns received by mail or by phone. If the message is on phone details of yarn received are collected from yarn godown. 2. Random samples of cotton yarn are sent for weaving as weft and verifying the fabric for appearance and feel. 3. The yarn sent should be used in fabric in the preferences as mentioned below: a. Should be used as weft with any black warp running. b. Should be used as weft with any dark colour warp running.

362

4. 5.

6. 7. 8.

Handbook on Fabric Manufacture

c. Should be used as weft in any design which can produce contrast. d. In case the yarn to be tested is black, the yarn should be still used as weft with contrast warp. In case of cotton the fabric is sent for washing and drying. In case of polyester or fancy yarns, board appearance will be checked and yarn will be approved on the basis of supplier test report and board appearance. The boards are prepared and compared against previous supply. After going through all tests decision is taken whether to approve for usage or disapprove for returning to the supplier. In case of doubt the matter is referred to designer for his opinion. The decision is informed to PPC and yarn godown.

22.4.2

Measurement of density of soft wound package

Purpose of this test is to ensure that the density of the yarn package prepared for dyeing meets required standard i.e. 360–380 Grams per Litre and to return back the cones to rewinding which are below 360 GPL & above 380 GPL. The procedure used is as follows. (i) Selecting the machine from which cone has to be taken for testing. (ii) For selecting the machine, sampling plan is made in such a way that all the machines are covered within a specified period. (iii) Collecting the soft wound packages spindle wise from machines. (iv) Measuring the following dimensions of each package (the figures given below in the brackets are the standard figures to achieve 370 GPL in 1.2 kg package). a. Top clearance – 10 mm. b. Bottom clearance – 10 mm. c. Outer diameter: 180 ± 1 mm. d. Inner diameter: 70 ± 1 mm. e. Height of package : 150 ± 1 mm. f. Net weight of yarn: 1200 ±20 Grams. (v) Check for flowering of the package and reject the package with flowering. Inform production department. (vi) Check for improper shape of packages. Reject the package with improper shape. Inform production department.



Customer Services

363

(vii) Calculate volume using the formula Volume in CC = 0.78 ×

(Outer Dia mm2 − Inner Dia mm2 ) × Height mm2 1000

(viii) Calculate density using the formula: (ix) Density in Grams per Litre = (Mass in Grams × 1000)/volume in CC. (x) Flowering packages and improper shaped packages should be rejected.

22.4.3

Sectional warping inspection

The purpose of this process control study is to verify the performance of the sectional warping machine and to ensure that correct quality of material is fed to the next process. Checking procedure (i) Selecting the warping machine for inspection. Warping machine is to be selected in such a way that all the machines are covered within a specified period. (ii) Check for overall cleanliness of the machine, specifically at tensioners and creel part. (iii) Check for smooth surface of ceramic guides. If scratches or grooves found, then immediately bring to the notice of concerned shift officer/in-charge. (iv) Ensure movement of tensioners properly without any jams due to fluffs. (v) Check pneumatic pressure or suction on tensioners. (vi) Check the warp yarn tension manually by placing hand on warp sheet and check for any loose or tight ends. (vii) Check whether stop motion is working or not by lifting the thread from stop motion pin. (viii) Ensure smooth functioning of the cones and proper ballooning by checking package alignment. (ix) Ensure that the drum will stop before one revolution of drum when yarn breaks. (x) Check machine speed while warping and see that it does not exceed more than specified.

364

Handbook on Fabric Manufacture

(xi) Check the pattern against design sheet and ensure correct pattern is running. (xii) Check the beam length against PPC plan for its correctness. (xiii) Note down the yarn breakages section wise, reason wise, shade wise and classify breakages as due to spinning, winding and transportation. (xiv) Calculate the end breakages per 4 lakh meters using the below formula. Breakages per 400, 000 m =

Total breakage × 400, 000 Total ends × warp length (m)

(xv) Make a report of all the deviations found and to inform the same to warping in-charge.

22.4.4

Sizing machine inspection

Purpose of this process control study is to verify the performance of the sizing machine and to ensure feeding of correct quality material to the next process. Sizing is considered as the most important activity and there is a saying that “Good sizing is half weaving”. It is essential to ensure that the size pick up is as per norms and sizing is uniform throughout to get best results in weaving. Monitoring the sizing parameters is hence very important. Procedure adapted is normally as follows. (i) Select the sizing machine for inspection in such a way that all the working machines are covered with in a specified period. (ii) Check the design number against the design sheet. (iii) Check warping beam as specified in the design sheet. (iv) Note down the net weight and gross weight of beam before start of the process. (v) Check for cleanliness of the machine. (vi) Ensure that the passage of warp sheet is smooth i.e. without abrasion, without scratches on any moving part of the machine. (vii) Check the speed of the machine and ensure it running below the specified maximum speed. (viii) Check the size recipe and confirm the quantity and contents as per specification. (ix) Check the sow box temperature and compare with norms. (x) Check the drying cylinder temperature from monitor.



Customer Services

365

(xi) Check Refractive index % of size paste by refractometer. (xii) Check the moisture % from monitor. (xiii) Note down the readings of the squeeze roll pressure, immersion roll pressure, splitting zone tension from monitor. (xiv) Observe unwinding tension of wrapper’s beam manually by feeling. (xv) Ensure looseness or jerks during unwinding of warp sheet is avoided. (xvi) Ensure for absence of crossing of ends. (xvii) Check and note down the stretch % of sized beam. (xviii) Check number of lappers, lapper position and length of lapper during sizing. (xix) Check and measure the hard wastes generated. (xx) Calculate the size add-on of beam. (xxi) Inform the sizing beam performance to concerned person and bring to notice any abnormality found. Verify the action plan to eliminate the same. Standard (Example) • • • • • • •

Size box temperature: 90 ± 5 °C. Speed of machine: Max 40 MPM. Refractive index % of size paste: 7 ± 1%. Moisture %: 7 ± 1%. Stretch % of sized beam: below 1%. Lappers: 0.5 per 1000 ends of 1000 m each. Hard waste of yarn: Below 1.5 kg.

22.4.5 Process control in loom shed Purpose of this process control study is to verify the performance of the looms and to ensure correct quality of fabric is delivered to the next process. The procedure adapted is normally as follows for a shuttle less loom shed. (i) Take a round of the loom shed before starting the studies. (ii) Go through the previous day reports and note down the looms having deviations. (iii) Note down the defects observed on looms running. (iv) Stop the looms immediately if deviations are found and bring to the notice of concerned shift in charge to arrest the deviations.

366

Handbook on Fabric Manufacture

(v) Ensure the deviations are corrected. (vi) Check and ensure loom is having beam card and the loom monitor is working properly. (vii) Check and ensure that the shades of warp and weft yarn running are as per design sheet. (viii) Check and ensure that each loom run with minimum 3 feeders to avoid weft bar. (ix) Verify and ensure that the lot of warp and weft used are as specified. (x) If lot mix-up is found stop the looms and inform in-charge to take corrective action and to follow up for corrective action. (xi) Inform the chief of quality in case of lot mix. (xii) Check the looms for bottoms. Note down the looms and number of such bottom packages. Interact with weaver/supervisor for same and ensure that corrective action is taken. (xiii) Check stop motion as per the schedule. (xiv) Check for cross ends in beam. If cross end /ends found stop the loom immediately and ensure that it is corrected. (xv) Note down the following parameters Loom wise: A. Design No. B. Yarn count. C. Shade No. D. Lot No. E. Reed. F. Picks. G. Weave. H. Total ends. I. Running picks at start of time. J. Speed of machine. K. Number of warp and weft breaks during running along with analysis as. a. Area of break (left, middle or centre part of loom). b. Position of break (before back rest, between drop pin to heald frame, within heald frame, heald frame to reed, reed to fell of cloth). c. Breaks due to spinning, dyeing, preparatory or weaving. d. Running picks at end of time.



Customer Services

367

(xvi) (xvii) (xviii) (xix)

Enter all the above in the specified format. Collect breakage sample and analyse the reason. Calculate the breaks/CMPX [CMPX = 100,000 picks]. Check attending time, interference time and time for repair the loom. (xx) Inform abnormality, efficiency % and Breaks/ CMPX and any abnormality found to in-charge. Breaks / CMPX =

No. of breaks ×100, 000 Picks produced

Standards (Example) a. Warp attending time: Below 1 min. b. Weft attending time: Below 20 sec. c. Breaks CMPX (Air jet): Warp 4–5, Weft 7–8. d. Norms for breaks /CMPX (Rapier): Warp 5–6, Weft 4–5.

22.4.6

Greige fabric audit

By checking the greige fabric and giving feed back to the weaving section, number of defects can be arrested. Ensuring accuracy and reliability in the audit results is very important. Procedure (i) Select the fabric roll or the report randomly checked by inspectors in greige section. (ii) Take out respective fabric report and fabric roll and check all selected rolls. (iii) Cross check for greige width, length of roll, EPI, PPI. (iv) Cross check it with inspection report. (v) Look for any defects missed by the inspector and check for inspectors recording accuracy. (vi) In case if significant difference is found, call the concerned inspector along with the supervisor/officer/manager of grey inspection and re-examine the fabric to show them what had been missed out. (vii) Watch the inspector and analyse whether his skills are OK or need to be improved. (viii) Tabulate the audit result inspector wise.

368

Handbook on Fabric Manufacture

22.5

Market feedback and complaint analysis

Market feedback is the best source of input for making strategic decisions on the products to be produced, the quality levels to be maintained, investments to be made on new technologies, the training to be given to the operators and staff, the costs to be cut, the area to be concentrated, the priorities for the activities, and so on. It is therefore very essential to go in detail for each feedback and complaints and act on them in time. A sincere effort in solving the problems shall help the company to sustain in bad periods like recession. The managements should encourage their people to accept all criticisms in a positive way and take it as a base for further innovations.

22.5.1

Handling market complaints and taking actions

The objectives of handling market complaints and taking actions are follows: 1. To understand the customer perception and grievances regarding our products and services and addressing them effectively to assure customers of quality products and services. 2. To educate all concerned regarding the customer grievances and expectations and improving the systems to cater to the customers to meet their expectations. The responsibility, although lies with the top management, they can delegate the authorities down the line. The following is a typical example: • The concerned Marketing Head is responsible for interacting with the customers, understanding their grievances and communicating to the mills suitably for taking action, and convincing the customer suitably after getting the analysis of the complaint done by mills. • The Chief of Quality Assurance is responsible for getting the quality related complaints analysed and finding the root cause of the problem and periodically reviewing the trends in market complaints. • The concerned Head of Production is responsible for taking appropriate corrective and preventive actions to prevent such complaints from recurring. • The Chief of Commercial operation is responsible for getting the complaints due to commercial aspects analysed and actions taken. • The Unit Head is responsible for coordination and follow up for the actions and to send suitable reply to the marketing regarding the complaint observed. Customer complaints might be divided into broadly 2 parts, problem related to development (desk loom and yardages) and problem related to bulk.



Customer Services

369

The first part, viz the development (desk looms and yardages) are samples being developed and not a bulk supply. Hence it is a development activity and customer is validating the product. However, as he is paying for the yardages, his comments are treated like a complaint and corrective and preventive actions are taken. There are many occasions where customers do not get satisfaction upon receipt of desk loom mainly due to lack of proper finishing, lack of whiteness, not matching the colours and pattern or excessive delay. As business conversion is highly dependent on approval of DL, with speedy delivery, this area needs continuous monitoring and improvement. Similarly in case of yardages, lead time is 2 week maximum, there is no extra time available to make the DL, get the approval and then to start yardages. So yardages are made directly without any trial and have found that there are cases when final product do not match with the original CAD or samples and customer gets dissatisfied. In case of bulk the customer could be dissatisfied on account of colour matching, finish width, improper mending, variation or late delivery. There could be commercial matters like shortage and un-assorted packing. Procedure for handling complaint – general Procedure followed for handling market complaints in general is normally as follows 1. The marketing representatives (customer contact person) dealing with the products and customers receive complaints and feedbacks from the customer; may be orally or in writing. 2. The marketing representative contacts the customer either on phone or on email and gets the details of the problems being faced. He shall visit the customer if needed, depending on the seriousness of the problem and gets samples for analysis. 3. In case the customer is insisting on sending the materials back to the mills, a senior technician from quality assurance or production shall be deputed to analyse the complaint area. 4. The marketing representative collects the details of invoice number, design number, date of despatch from the mills, quantity supplied, nature of the problem being faced, quantity affected and the expectation of the customer. 5. The marketing representative discusses with the head of marketing and advises the customer to return the materials if needed, depending on the seriousness of the problem or settles the issue by mutual discussions. 6. The details are sent to the concerned Head of Marketing for recording.

370

Handbook on Fabric Manufacture

7. The marketing head groups the complaints in the categories of product quality, delay in despatches, short supplies, transport related issues, errors in documentation and miscommunication. Following table gives an indication as to who shall do what in case of a market complaint. Category of complaint

Analysis done by

Action taken Reply to Reply to by marketing by customer by

Product quality

Q.A

Production

Unit Head

Marketing

Delay in despatches

P.P.C

Production

Unit Head

Marketing

Short supplies

P.P.C

Production

Unit Head

Marketing

Transport related issues

Commercial

Commercial

Unit Head

Marketing

Errors in documentation

Commercial

Commercial

Unit Head

Marketing

Miscommunication

Marketing

Marketing

Not applicable Marketing

8. All complaints are allotted a complaint serial number which is restarted every year. The Complaint Serial Number shall indicate the number and the year. 9. The Head of the Marketing addresses the complaints to the Unit Head, who in turn will mark the complaints to concerned heads for analysis. 10. In the absence of Unit Head, Chief of Quality Assurance shall coordinate for analysis of the complaints and replying to the marketing. 11. The product quality related complaints are forwarded to the Chief of Quality Assurance for analysis and other complaints as explained in the table above. 12. The quality assurance shall analyse the complaint and compare with the agreed specifications and norms. They analyse the complaint part and try to find the source of problem as raw material related, yarn dyeing related, weaving and preparatory related, processing related and whether it is a technical problem or a human related problem. The analysis shall be discussed with the concerned process owner. 13. The Chief of Quality Assurance shall fill up the details in the market complaint analysis for the product quality related complaints in a specified format and attach to the complaint received. 14. The Chief of Quality shall draft a reply to the marketing regarding the findings of the analysis and the actions taken and takes approval of the Unit Head before sending it to marketing.



Customer Services

371

15. The concerned heads of the department shall communicate down the line regarding the complaint received, findings of the analysis, the root cause, the actions to be taken, precautions to be taken while producing a similar material and shall show the complaint sample to all involved. 16. The complaint sample shall be kept on display for a week so that all the workers from all shifts can see that complaint and understand the precautions to be taken. 17. After one week, the sample shall be collected by the quality assurance section and kept for future reference. 18. In case of non-product quality related complaints, the concerned persons to take action shall be called and briefed by the Head of the Department, and his signature shall be taken as a proof of him being told about the problem and the complaint. 19. In case of transport related issues, the concerned transporter shall be called and the complaint shall be explained. 20. In case there is damage to the materials during transport for which customer has made complaint and claims, the same shall be shown to him and compensation shall be claimed. 21. The Chief of Quality Assurance shall analyse the trends of complaints reason wise, customer wise and product wise and submit for periodic management review. Procedure followed by marketing section for handling complaints The procedures followed specifically in marketing shall normally be as follows. The complaint related to development is handled by the marketing and the customer is satisfied through verbal dialogue. In case of bulk, if the nature of complaint is commercial, the required details pertaining to invoice, bale and piece are taken from customer and forwarded to QA through customer complaint form. In case of technical issues like shrinkage, colour, finish etc., the required sample is requested from the customer and is sent along with the customer complaint form which is made by respective Marketing Executive and signed by HOD. Complaints for bulk a. The feedback/complaint is forwarded to the plant QA who will gather information and study the reason and action plan will be submitted to the management to minimize such problems in the future. b. One file is created within marketing so that respective Sr. Marketing Executive can fill up/log the complaints maintaining a serial number before sending the same to PDC and QA.

372

Handbook on Fabric Manufacture

c. In case of bulk dispatch, the complaints might arise from different sources as follows. a. Fabric is containing defects more than 4 point system of checking. b. The bulk finish/whiteness/lustre, etc., is not up to the mark or even different than customer approved standard sent. c. Fabric performance parameters are not matching as per industry norms or in house test report. d. Complaints like late arrival of goods, not having documents, not having shipping marks, etc., e. About short receipt e.g. packing list and Invoice is showing 100 m and upon checking they have found 95 m. f. Also complaint like short close against desired quantity of each design, i.e. more than tolerance level (±5%) d. The same is then informed to the plant QA and actions taken accordingly. Handling goods returns a. In case the customer is not satisfied with the materials, they may return the materials back to us. b. In case of goods return, normally customer first informs the problem in the goods and informs the senior executive in Marketing by mail or phone. The same is communicated to Head Marketing for approval with reasons for approval, if the reasons are technical in nature the production team is informed for the same thru email. c. Depending on the magnitude of problem and the quantity of goods returned, a person from plant visits the customer to understand the problem. d. In case of genuine complaint, marketing tries to negotiate some discount based on consumption level of the fabric by the customer. However if there is no agreement, goods are called back. e. However there are cases when at times buyer does not inform anything and simply sends back the fabric and followed by LR. Also there are situations when buyer does not want to negotiate any discount and want the goods returned mainly due to defects or late delivery. f. Once Goods Returned document is received in marketing, GR form is filled up mentioning the reason. All the details are attached relating to GR matter are attached to the form, which is approved by HOD



Customer Services

373

Marketing. Then it is handed over to accounts, who in turn follows up the matter with the plant and also sends the documents mainly LR to take the delivery of GR. g. After delivery plant opens the goods and checks the number of metres and tally with the customer challan metres, design, defects, lot No etc. Accordingly GRN is prepared and accounts receive the GRN from the plant to the make the credit note. The Credit note is received by the sales accountant. h. Upon receipt of Credit note, the balance payment is received from the customer and submitted to accounts through Payment book register. Poor quality settlement a. In case of seconds, defective goods, bulk not matching with the approved standard, the marketing executive first tries to convince customer to accept as it is. b. If failed brings to the notice of HOD Marketing, who does final negotiations as per management guidelines. a. Case A: Goods graded and found certain % as seconds: Marketing should inform about seconds to concerned customer and negotiate a minimum discount. After negotiation the same should bring to the notice of HOD/Management/Settle and accordingly dispatch. b. Case B: Shipment sample sent to buyer and customer finds deviation in matching colour and design compared to approved standard: In such situation marketing can inform plant about the customer complaint by email and if the parameters can be improved to a desired level plant resubmits the sample and marketing re-sends the same. If parameters cannot be improved, once again negotiation and same as above. c. Case C: After grading marketing advised packing the seconds as A grade and dispatch to the customer: Sometimes marketing wants to take a chance and doesn’t want to inform customer initially and advices packing to upgrade seconds as fresh and dispatch. In this system there is always a chance of getting a complaint afterwards and also risk of losing the brand image. d. Case D: Goods dispatched as fresh as per packing and customer has found certain defects after opening the goods. In this case marketing informs the plant and from plant QA persons visit customer’s office/factory along with marketing (wherever possible) and evaluates. After visit the plant representative submits a report

374

Handbook on Fabric Manufacture

of actual findings and accordingly either claims settlement or goods return takes place. e. Case E: Fabric performance parameters/test report does not match the industry norms. The marketing will refer the case to the plant to rectify the fabric and to bring it within the norms if fabrics are with us. If fabrics are dispatched and customer finds the deviation in his lab, settlement is done on the basis of third party lab report coupled with visit report of QA and marketing person. Call is taken by HOD and final approval is given by MD. c. In case of claims for shortages, quality, short payments and any ­deductions – HOD has power as per prescribed norms to accept the same as per authenticity of the claim. The same is signed by HOD and forwarded to accounts for entry and MD’s approval required in some cases.

22.5.2 Handling situation in case of customer order cancellation A customer can cancel the order in the following situations as per the rules of Government of India: a. By mutual agreement: If neither party has performed the contract, no consideration is required for the release. If a party has performed a part of the contract and has undergone expenses in arranging to fulfil the contract it is necessary for the parties to agree to a reasonable value of the work done as consideration for the value. b. By breach: In case a party to a contract breaks some stipulation in the contract which goes to the root of transaction, or destroys the foundation of the contract or prevents substantial performance of the contract, it discharges the innocent party to proceed further with the performance and entitles him to a right of action for damages and to enforce the remedies for such breach as provided in the contract itself. A breach of contract may, however, be waived. c. By refusal of a party to perform: On a promisor’s refusal to perform the contract or repudiation thereof even before the arrival of the time for performance, the promisee may at his option treat the repudiation as an immediate breach putting an end to the contract for the future. In such a case the promisee has a right of immediate action for damages. d. In a contract where there are reciprocal promises: If one party to the contract prevents the other party from performing the contract, the contract may be put to an end at the instance of the party so prevented and the contract is thereby discharged.



Customer Services

375

In case of cancellation of an order the following points are to be observed. a. If the product(s) has not been shipped, the purchaser must inform the supplier that the product(s) is not required, that they are not to ship the product(s), and that a formal purchase order cancellation will be issued and transmitted to the supplier. b. If the product(s) has been shipped, cancellation is disallowed. In this case, resolution must be addressed via a Return Goods Authorization (RGA) and supplier credit memo. The invoice for the shipment must be paid and the supplier credit will offset the invoice that was issued upon shipment of the product(s) by the supplier. c. If the supplier receives POs via EDI, cancellation is not allowed. In all cases, resolution must be addressed via a Return Goods Authorization (RGA) and supplier credit memo. The invoice for the shipment must be paid and the supplier credit will offset the invoice that was issued upon shipment of the product(s) by the supplier. Because the order entry and processing is immediate on the supplier side when using EDI, there is no viable way to prevent a shipment from being queued.

22.6 Controlling of non-conformance and taking corrective actions Controlling nonconformities and taking corrective actions are very essential for any company to survive and flourish. There needs to be a systematic approach, followed as a procedure for this. This procedure has an objective to take corrective actions for the non-conformities found in products, systems and processes by understanding the root cause and working to eliminate it. Definition of Non-conformity: 1. Any deviation found in the product from the required specifications which is not acceptable to customer. 2. Any deviation found in the implementation of systems from the accepted procedure/norms which can reduce the efficiency of the system. 3. Any deviation found in the process from the planned parameters which can affect the quality of product or service. 4. The dissatisfaction expressed by the customer [internal as well as external] relating to product and services. 5. Lapses in adhering to accepted/specified standards laid out in the Quality Management System. 6. Lapses in adhering to the specified safety and legal requirements.

376

Handbook on Fabric Manufacture

Procedure normally followed are as follows: Product nonconformity: Once the nonconformity is observed in a product, [either by the production personnel or by the Quality Control people], the material shall be segregated from the regular materials. The nonconforming products shall be kept at a designated place till the decision on the correction is taken. The Head of the Department shall discuss with the concerned Marketing Account Holder and Quality Assurance personnel to decide on the correction to be made, i.e. whether to allow the material to go to customer as it is, or down grade and give for an alternative end use, or rework or scrap the material. 1. The quality assurance personnel and production personnel shall jointly work to identify the root cause of the problem. 2. Action shall be taken by the production personnel, and the effects are reviewed by the quality assurance personnel. Process nonconformity: 1. In case of a deviation found in process, which is affecting product quality, the process shall be stopped. The in-charge of the process shall arrange for the rectification of process, and bring to the notice of the Head of the Department. 2. The quality assurance and production personnel shall jointly assess the damages, if any, to the product, and shall take back the material. 3. The root cause analysis shall be made by the concerned production personnel and corrective action shall be taken. The procedures shall be modified if required. 4. The process shall be verified by the quality assurance person after corrective action is undertaken. System nonconformity: 1. The deviations found in system shall be discussed by the auditors with the concerned Heads of Department. 2. The root cause for the deviations shall be worked out by the concerned HOD. 3. The effect of the deviation on the product quality and in achieving company objectives shall be verified. 4. The system shall be brought back or suitable amendment shall be made in the documents. 5. The modifications are verified by the internal auditors.



Customer Services

377

Customer feedback/complaints: 1. The customer feedback/complaints shall be recorded at quality assurance department with the details of complaint received date, the customer, the product and the nature of problem faced by customer. 2. Analysis shall be made of the samples received to understand the possible reason for the defect. 3. The manufacturing period shall be traced back by the concerned production personnel if possible, and the records are verified to find out possible clues for the nonconformity observed. 4. The complaint samples and details shall be shown to all the concerned staff and operatives, so that they can help in identifying the root cause, and also in formulating a suitable preventive action. 5. The concerned Heads of the Department shall spell out the actions being taken to avoid such complaints, and the Q.A. shall verify the actions taken. 6. A report shall be prepared by the Q.A. and submitted to Unit Head, who shall then discuss the matter with the concerned H.O.D for the necessary corrective actions and changing the systems as needed. Incoming materials: 1. In case nonconformity is observed in the incoming material, the concerned vendor shall be informed by the sourcing personnel, and the materials shall be kept separately at an identified place. 2. The matter shall be discussed, and decision shall be taken as to whether it can be used with modifications/additional care or for alternate end use. If it is not suitable, the material shall be returned back. Safety and Regulatory requirements: 1. In case nonconformity was observed either during the investigation of an accident or reported by the supervisor of the concerned department or noticed as nonconformity during internal audits, the matter is reported to Chief of Human Resource Development. 2. The Chief of Human Resource Development shall discuss the matter with the Safety Officer and the Chief Engineer and workout the action plan for rectifying the nonconformity and discuss with the Unit Head. 3. The Unit Head shall review the situation and ensures that necessary corrective actions are taken. Fig. 22.12 is a flowchart explaining the general procedure of corrective actions normally followed in various manufacturing units including textiles.

378

Handbook on Fabric Manufacture

Figure 22.12 The flowchart explaining the general procedure of corrective actions

22.7

Preventive actions

It is essential to prevent problems rather than taking corrective actions after a problem has caused damages. There needs to be a procedure documented and followed religiously. The intention of this procedure is to initiate identification of the potential non-conformities/problems and take preventive actions proactively. Procedure: 1. Potential problems are identified by studying the trends, understanding the changes that are taking place in technical, technological,



Customer Services

2.

3.

4.

5.

6.

7.

8. 9.

10. 11.

379

social and economic fields, seasonal changes that normally affect performance, natural calamities those hit unexpectedly and the non-conformities/problems in a similar work culture noticed. The HODs during their periodic performance reviews, invite the members to indicate any potential problem which is likely to affect the performance. The marketing team shall highlight the changes in customer’s requirements from time to time, which help the PPC and production personnel to proactively work out the possible problems they are likely to face in machine configurations, the raw material availability and the short of skilled labour. The Unit Head shall be studying the changes in technology and market trends and identifies the problems likely to surface in future and advises the Head Office and strategy is worked out to face the situation. The order feasibility study done by P.P.C and P.D.C under the guidance of Unit Head and FMEA analysis {Failure Mode Effect Analysis} by product development cell indicate any problem likely to arise because of constraints, if any. Anyone who predicts a potential problem/non-conformity shall inform their seniors who shall make a note of the same and submit to the Head of the Department. The Head of the Department shall study the same and verify the actions already initiated, if any, to prevent such non-conformities or problems. If already an action is in force, the same shall be shared with the person who identified the potential problem. In case no action is in force, the HOD shall work out a strategy to overcome the problem if it arises, either by forming a team or by taking help of experts in the field. Root cause analysis shall be made to prevent the problem from its source. Such analysis and actions taken are reported to top management which are reviewed in the management review for its effectiveness.

References

1. K. Roy Choudhury. Textile Preparation and Dyeing – 2006 Google Books – books. google.co.in 2. Ashar Waqar. Fabric Defects – http://www.scribd.com/doc/119281850/ Fabric-Defects 3. Purushothama (2011), A Practical Guide to Quality Management in Spinning. Woodhead Publishing India 4. Purushothama (2007), Guidelines for Process Management in Textiles. CVG Publications 5. B. Purushothama (2011), Training and Development of Technical Staff in Textile Industry. Woodhead Publishing India 6. B. Purushothama, Textiles – Care, Salvaging and Recirculation – Reading Materials for B.A Textiles. Yeshvantrao Chavan Maharashtra Open University 7. B. Purushothama (1973–1974), A Treatise on Developments in Sizing. Thesis submitted to SKSJT Institute, Bangalore University 8. Bhuvenesh C. Goswami, Rajesh D Anandjiwala, David Hall (2004), Textile Sizing. CRC Press 9. ChemKnits Tutorials – Space dyeing Yarn: Creating multi-coloured yarn on stove with food colouring 10. B. Ajagaonkar, Sizing 11. Debbie Colgrove, Basic sewing kit – Licensed to About.com 12. Elizabeth Bittner, Basic Textile Care: Structure, Storage, and Display – Fall 2004: http://webspace.utexas.edu/ecb82/textile_care.doc 13. J. R. Modi and P. C. Mehta, Chemical Processing Tablet – I. Mercerization – The Textile Association (India) 14. J. R. Modi and T. V. Ananthan (1983), Weaving Tablet III – Sizing – The Textile Association (India) 15. Leigh, Waffle weaves - Posted 15 July 2008 at http://leighsfiberjournal.blogspot .com 16. M. K. Talukdar and T. V. Ananthan (1988), Weaving Tablet IV – Non-Automatic Looms – The Textile Association (India) 17. M. V. Koranne (2013), Fundamentals of yarn winding 18. P. D. Kimothi and T. V. Ananthan (1983), Weaving Tablet II – Warping – The Textile Association (India) 19. Paul Vasser Seydel, James Robert Hunt, Textile Warp Sizing – Google Books 20. R. Sengupta, Yarn sizing 21. S. R. Karmarkar, Chemical technology in the Pre-treatment process of textiles – S.R. Karmakar, Google Books 22. Sabit Adanur (2000), Handbook of Weaving 23. Sarah Cage, Space Dyeing with Fibre Reactive Dyes. Birmingham Guild of Weavers Spinners & Dyers



References

381

24. Sheikh Nurja, Bottom Close Shed - Ordnur Textile & Finance > Textile > Bottom Close Shed 25. Tamer Albagoury, Fabric defects – http://prezi.com/bsoc1oynoegb/fabric-defects/ 26. Thomas W Fox (1922), Mechanism of Weaving – Textile Book Service 27. Machinery catalogue and operating instructions supplied by the machinery manufacturers. 28. Manuals and leaflets given by the dyes and chemical manufacturers from time to time. 29. http://dyeingworld1.blogspot.in/2009/12/yarn-mercerizing.html 30. www.wisegeek.com/what-is-space-dyeing.htm 31. Dyeing and Processing: Space Dyeing Techniques: dyeingworld1.blogspot.com /2009/12/space-dyeing-techniques.html 32. Space Dyed Yarn with Acid Dyes Tutorial – Dharma Trading Co. www.dharmatrading.com/.../space-dyed-yarn-with-acid-dyes-tutorial.ht 33. Multi-Colour Space Dyeing Machines (8 Colours): Blue Moon – www.bluemoonmachines.com/multi_colour.htm 34. Bondex Tapes – http://www.simplicity.com/p-9538-assorted-bondex-iron-on-mendrepair-patches-2-x-3-8-pcs.aspx 35. Mending Material by Thermopatch http://www.thermopatch.biz/us/en/products/ supplies/mending-material/129 36. Learn to Mend Your Clothing - Replace Zippers, Fix Ripped Seams and more – http://sewing.about.com/od/techniques/tp/mendclothing.htm 37. How to repair a wool sweater with felting – http://makezine.com/craft/ how-to_repair_a_wool_sweater_w/ 38. Leeds sample fulfilment – http://www.leedsamples.com/category/employee-news/ 39. Fabric sample cutting machine – max. 250 cm | ZEN Hoza-Cutter GmbH http://img.directindustry.com/images_di/photo-g/fabric-sample-cutting-machines-64073-2609943.jpg 40. Sample Making Machinery » Brand ALMAC » MSCM http://www.almac-machinery.com/Product.aspx?PId=18 41. Fabric Sample Cutting Machine http://www.indiamart.com/texmech-engineers-thane/fabric-sample-cutting-machine.html 42. CABC – SA Textile Dictionary 43. Textile Learner’s blog – What is winding? (Textile learner Blog spot) 44. Textile School – Automatic Cone Winding – http://www.textileschool.com/ articles/401/automatic-cone-winding#22695 45. Textile Fashion Study – What is winding/Objectives and requirements of winding process http://textilefashionstudy.com/ what-is-winding-objectives-and-requirements-of-winding-process 46. My Textile Notes – Warp preparation for rope dyeing 1 – http://mytextilenotes.blogspot.in/2008/10/warp-preparation-for-rope-dyeing-1.html 47. Woven Fabric Production – I. NCUTE 48. Introduction To Clothing – Text Books – www.textbooksonline.tn.nic.in/books/11/ stdxi-voc-textiles-em.pdf 49. Basic Woven Structure – Fabric Structure: http://textilelearner.blogspot.in/2012/07/ basic-woven-fabric-structure-plain.html 50. A Textile Lover’s Dairy – Dictionary.

382

Handbook on Fabric Manufacture

51. Shedding Mechanism in Weaving Process – http://textilelearner.blogspot.in/2013/09/ different-types-of-shedding-mechanism_4.html 52. Jacquard Shedding – http://www.definetextile.com/2013/07/jacquard-shedding_18. html 53. Dr. Emel Onder and Dr Omer Berk Berklap – Jet Weaving – http://web.itu.edu. tr/~berkalpo/Weaving_Lecture/Weaving_Chapter8_Airjet.pdf 54. Maruf Mahfuz – Study on different types of looms – http://textilelearner.blogspot. in/2013/07/different-types-of-loom-conventional.html 55. Weaving weft insertion rapier: Principles – Modern Textile Journal – http://www. fibre2fashion.com/industry-article/10/946/weaving-weft-insertion-rapier1.asp 56. Basics of Weaving and Types of Shuttle less Looms –By  admin Sep�tember 30, 2014 – IIMT Studies – http://iimts.edu.in/technology/ basics-of-weaving-and-types-of-shuttleless-looms/ 57. Water-jet Weaving Machine (Water Jet Loom) | Working Principle of Water Jet Loom – http://textilelearner.blogspot.in/2012/05/water-jet-weaving-machine-water-jet.html 58. Shubham Yadav – Air Jet Loom - http://textilelearner.blogspot.in/2013/01/mainparts-of-air-jet-loom-for-weft.html 59. S. Sudarshan, P. Ganesan, S. Hariharan – Critical efficiency analysis in projectile looms 60. Definition of loom | Classification of loom | Different parts of loom – http://textileapex.blogspot.in/2014/01/loom.html 61. Multi Axial Fabric – http://www.primaryinfo.com/projects/multiaxial-fabric.htm 62. Multiaxial Fabrics – http://www.netcomposites.com/guide/multiaxial-fabrics/42 63. Mario Lima, Raul Fangueiro, Antonio Costa, Christien Rosiepen, Valter Rocha (March 2007), Multi Weave, a prototype weaving machine for multi axial technical fabrics. Ind J Fibre Textile Res, 34 64. Angela Durie, Ross Griffith, Alan Tomlinson, Multiaxial Compound Weave Method for Preforms 65. Abdel-Fattah M. Seyam, Ph.D., Technical Editor – ITMA Technology: Weaving & Weaving Preparation – Textile World - January/February 2012 66. ITM TEXPO EURASIA 2013 – Pakistan Textile Journal – http://www.ptj.com.pk/ Web-2013/07-2013/ITM-TEXPO-EURASIA-2013-Dornier.html 67. Kadir Bilisik, Multiaxis Three Dimensional (3D) Woven Fabric – http:// www.intechopen.com/books/advances-in-modern-woven-fabrics-technology/ multiaxis-three-dimensional-3d-woven-fabric 68. 3D-Weaving – Textile Learner - http://textilelearner.blogspot.in/2011/08/3d-weaving-manufacturing-process-of-3d.html 69. Jim Kaufmann (July August 2012), An Introduction To 3-D Weaving – Part one of a two-part series about 3-D weaving and its current and potential applications – Textile World 70. 3D Weaving – Textile Innovation Knowledge Platform – http://www.tikp.co.uk/ knowledge/technology/warping-and-weaving/3d-woven-fabrics/ 71. Khubab Shaker, Sample Warping machine 72. The art of visual merchandising – www.fibre2fashion.com – https://www.academia. edu/3781633/Sample_Warping_Machine 73. Wipro technologies – Retail Marketing – www.wipro.com 74. John Fernie & Leigh Sparks, Logistics and Retail Management – Insights into Current Practice and Trends from Leading Experts). Kogan Page



References

383

75. Romo – How to order fabrics and wall covering samples – https://www.romo.com/ swatches 76. Textile Sample – Wikipedia – Free encyclopaedia – https://en.wikipedia.org/wiki/ Textile_sample 77. Clive Hallet and Amanda Johnston, Fabric for Fashion: The Swatch Book: Second Edition with 125 Sample Fabrics – (ISBN: 9781780672335) from Amazon’s 78. B. Purushothama (September 1979), Towards Scientific evaluation of loom shed performance. J Textile Assoc

About the Authour

B. Purushothama, an awardee of ‘TAI Ratna’ by The Textile Association India, is a textile technologist having post graduate degree of M.Sc (Technology) from Bangalore University and Post graduate Diploma in Business Administration, and having 43 years of industrial experience in textile industry. He is a Fellow of Textile Association India, Fellow of Institute of Engineers and a life member of Asian Network for Quality, Indian Society for Technical Education and Kannada Sahitya Parishat. He has worked in the shop-floor and in various sections. He is an expert in Quality Management Systems, a lead auditor in ISO 9001 and a certified quality analyst. He has written number of technical and management books and published number of papers in various national and international conferences. His popular technical and management books are 1. Fundamentals of Textile Mills Management – The Textiles Association India, Miraj Unit 1980 2. ISO 9001:2000 Guidelines for Internal Quality Audits – In English and Kannada – Published by Gokak Mills – 2005 3. Guidelines for Process Management in Textiles – CVG Publications – 2007 4. Quality Management in Garment Manufacturing – Indian Society for Technical Education – 2007 5. Winning Strategies – Pubadchi Publication – 2009 6. Humidification and Ventilation Management in Textile Industry – Woodhead Publishing India 2009 7. Effective Implementation of Quality Management Systems – Woodhead Publishing India – 2010 8. A Practical guide to Quality Management in Spinning – Woodhead Publishing India 2011 9. Training and Development of Technical Staff in Textile Industry – Woodhead Publishing India 2011 10. Principles of Textile Testing and Statistics – The Textile Association (India) 2011 11. Process Control in Spinning – The Textile Association (India) 2011



About the Authour

385

12. Garment Technology – The Textile Association (India) 2012 13. Work Quality Management in Textiles – Woodhead Publishing India – 2013 14. Solutions to problems in Textile and Garment Industries – Woodhead Publishing India 2014 15. Implementing ISO 9001:2015 – Woodhead Publishing India – 2014 16. Hand book on Cotton Spinning Industry – Woodhead Publishing India – 2015 He is also active in Kannada literature and has written number of books which include novels, devotional songs, thought provoking humours and so on. He has given the concept of Five Golden Questions, Work Quality Management, Measuring implementation of Quality Management Systems, Multiple Twist Winding and a technique for measuring customer satisfaction. He is actively involved in guiding number of textile units, technical institutes and management institutes. He is also actively involved in the activities of The Textile Association India.

Index

3D orthogonal fabric, 195 A Air jet looms, 183 Air jet technology, 178 B Back printed memo samples, 308, 309 Ball warping, 111, 113, 115 Balloon breaker, 50, 184 Basic basket weaves, 147 Beam rolling, 113, 114 Beam warping, 110, 111, 115 Beating up, 168 Beat-up, 168 Book folding, 287, 289, 296 Bottom-closed shed, 177 Brittle yarn, 72, 140 Brocade, 155 C Centre-closed shed, 174, 176 Chain memo samples, 309, 310 Charmeuse, 151 Chiffon, 148 Closed shed, 176 Coarse end, 215 Coarse pick, 215, 238 Cone winding, 4, 6, 8, 9, 10 Conventional or random winding machines, 48 Corduroy, 156 Count mix-up, 35 Creeling, 109 Crepe de Chine, 155 Crepe weaves, 154 Crepe-back satin, 154

Crossed ends, 120 Crossing or winding angle, 44 Cupping, 44 Cut pile, 156 Cutting finished fabrics, 282 D Damask, 155 Darning, 262 Denim, 150 Desk looms, 349 Diamond weave, 149 Diaper weave, 150 Digital cards, 306 Dobby fabrics, 155 Dobby shedding, 171 Double cloth, 157 Double end, 221 Double folding machine, 296 Draw back, 122 Draw warping, 111, 112, 130 Drawing-in, 158, 159, 161, 162 Drum winders, 4 E Electronic Yarn Clearer (EYC) failures, 14 Entering, 158 Excessive lappers, 140 F Fabric sampling, 302 Front rest, 167 Fully-open shed, 174 G Gabardine, 150

388

Handbook on Fabric Manufacturing

Georgette, 148 Good cutting, 285 Greige fabric audit, 367 Grey fabric inspection, 250 H Hand folding, 294 Hank dyeing, 97 Hard edge formation, 50 Hard packages after rewinding, 73 Hard winding, 23 Heald shaft, 167 Heddle, 167 Herringbone weave, 149 Honey comb weaves, 152 HTHP yarn dyeing, 59 Huck a back weaves, 152, 169

Mending, 258 Mercerising process, 86 Missing ends, 120 Mock Leno, 152 Monks cloth, 148 Motorised sample cutting machine, 315 Multi-axial weaving technology, 187 Multi-axis 3D fabric, 197 Multi-axis three dimensional (3D) woven fabric, 195 Multi-phase loom, 186 Multi-phase weaving technology, 178 N Needle weaving technology, 198 Negative dobby shedding, 171

I

O

Ideal dye package, 51 Improper shade, 72 Individual hanging samples, 311

Open shed, 174 Oxford, 149

J Jacquard fabrics, 155 Jacquard shedding, 172 Jet looms, 182 K Knitting, 1 L Labelled memo samples, 309 Lease rods, 167 Length measuring device, 50 Leno weave, 151 Let-off motion, 166 Lost end, 122 M Manual sample cutting machine, 314 Mapping faults, 282 Memo samples, 303

P Package density, 57 Package holder, 46 Package stability, 45 Package weight, 48 Packing, 290 Pad cards, 305 Patterning or ribbon formation, 49 Perforated cones, 46 Picker, 167 Picking, 167 Pile fabrics, 156 Plain weave, 146, 147 Poor fastness properties, 72 Positive dobby shedding, 171 Precision winders, 4 Presentation boards, 306 Presentation hangers, 312 Projectile looms, 179 Projectile technology (gripper technology), 177

R Random winding, 52 Rapier (flexible & rigid) technology, 177 Reaching, 158 Reed, 168 Regular basket weave, 147 Ribbon formation, 35 S Sample books, 303 Sample cards, 307 Sample cutting machines, 314, 315 Sample hangers, 310 Sample presentation, 303 Sandwich cards, 304 Sateen, 150 Satin/sateen weave, 150 Section mark, 245 Sectional warping, 363 Seersucker, 148 Semi-open shed, 175 Shade bar, 215 Shade variation between cheeses, 71 Shade variation within cheeses, 71 Shade variation within cones, 15 Shantung, 148 Shedding, 167 Shuttle box, 167 Shuttle loom shed, 203, 204 Shuttle looms, 227 Shuttle, 167 Shuttle-less looms, 227 Side stitches, 35 Single folding machine, 295 Sley, 167 Slitter, 317 Soft winding, 21, 23 Soft/bulged cones, 14 Space dyeing, 97–99 Specialised books, 314 SS dye springs, 46 Stack books, 312 Stains, 72

Index

389

Step-precision winding, 54 Stitches, 14 Strength drop after dyeing, 72 Sunken nose/base, 14 Surface mounted cards, 303 Swatch cards, 303 T Take up motion, 168 Tappet shedding, 168 Temple, 168 Textile marketing, 323 Textile warping, 109 Thick end and thick picks, 214 Transfer tail, 109 Traverse of the package, 50 Treadle, 168 Triaxial fabrics, 192 Twill weave, 149 U Uncut pile, 156 Uneven dyeing, 72 V Velvet, 156 Velveteen, 156 W Waffle weave, 153 Warp printing, 97 Warp stop motion, 168 Warp streaks, 214 Water jet looms, 184 Waterfall books, 313 Waterfall cards, 305 Waterfall sample cutting machine, 317 Weaving machines & embroidery unit, 178 Weft bar, 214 Weft insertion, 350 Weft stop motion, 168 Weight release mechanism, 50

390

Handbook on Fabric Manufacturing

Weight variation between cones, 14 Wicker weaving techniques, 148 Winding ratio, 45 Winding speed, 51 Wrong cone tip or cone label, 15

Y Yarn dyeing supervisor, 65 Yarn singeing, 77 Yarn tension controlling, 50 Z Zigzag weave, 149