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PRINCIPLES OF
WOVEN FABRIC MANUFACTURING
PRINCIPLES OF
WOVEN FABRIC MANUFACTURING
ABHIJIT MAJUMD MAJUMDAR AR
CRC Press Taylor & Francis Group 6000 Brok Broken en Sound Parkway N NW W, Suite 300 Boca Raton, FL 33487-2742 © 2017 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to origina l U.S. Government wor works ks Printed on acid-free paper Version Date: 20161014 International Standard Book Nu Numbermber-13: 13: 978-1-4987 978-1-4987-591 -5911-3 1-3 (Hardback) This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged acknowledged please write and let us know so we may rectify iin n any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright. com (http://www.copyright.com/ ) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood com Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted g ranted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and a nd are used
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Library of Congress Cataloging-in-Publication Catalogi ng-in-Publication Data
Names: Majumdar, Abhijit, author. Title: Principles of woven fabric manufacturing / Abhijit Majumdar. Description: Boca Raton : CRC Press, 2017. | Includes bibliographical references and index. Identifiers: LCCN 2016025821 | ISBN 9781498759113 (hardback : acid-free paper) Subjects: LCSH: Weaving--Textbooks. Classification: LCC TS1490 .M327 2017 | DDC 677/.028242--dc23 LC record available at https://lccn.loc.gov/2016025821
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Contents Preface, xvii Acknowledgeme Acknowl edgements, nts, xi xixx Author, xxi CHAPTER 1
◾
Introduction Introduct ion to Fabric Manuacturing
1
1.1
FABRIC MANUFACTURING MANUFACTURING TECHNOLOGIES
1
1.2
WEAVING 1.2.1 TypesTECHNOLOGY of Looms
23
1.2.2
1.2.3 1.2.4 1.2.5
1.3
Primary Primar y Motions 1.2.2.1 Shedding 1.2.2.2 Picking 1.2.2.3 Beat-Up Beat-Up Secondary Motions Auxiliar Auxi liaryy Motions Some Basic Definitions 1.2.5.11 Yarn Count 1.2.5. 1.2.5.2 Packing Factor or Packing Coecient 1.2.5.33 Warp and We 1.2.5. 1.2.5.4 Crimp Crimp 1.2.5.5 Fractional Cover and Cover Factor 1.2.5.6 Porosity 1.2.5.7 Areal Density
5 5 6 8 8 9 9 9 10 12 12 12 13 15
KNITTING KNIT TING TECHNOLOGY
17
1.3.1 1.3.2
18 19
We Knitting Knitt ing Warp Knitting Knitt ing
v
vi
Contents
◾
1.4
1.5
1.3.3
Needle
19
1.3.4
Loop Formation in Knitting Knitt ing
20
1.3.5
Course Cours e and Wale
21
1.3.6
Single Jersey and Double Jersey Fabrics
22
1.3.7
Tightness Factor
23
NONWOVEN TECHNOLOGY
25
1.4.1
Needle Punching Technology
25
1.4.2
Hydro-Entanglement Hydro-Entang lement Technology echnolog y
26
1.4.3
Spunbond Technology echnolog y
27
1.4.4
Meltblown Technology echnolog y
28
BRAIDING BRA IDING TECHNOLOGY
NUMERICAL PROBLEMS REFERENCES CHAPTER 2
◾
Winding
29 31 36
37
2.1
INTRODUCTION
37
2.2 2.3
OBJECTIVES TYPES TYPE S OF YARN WITHDRAW WITHDR AWAL AL
37 38
2.4 2.5
TYPES TYPE S OF WOUND PACKAGES IMPORTANT DEFINITIONS OF WINDING
40 41
2.5.1
Wind
41
2.5.2
Traverse Ratio or Wind Ratio or Wind per Double Traverse
41
Angle of Wind and Coil Angle
41
2.5.3.1 Measuring the Angle o Wind
42
2.5.4
Winding Speed
43
2.5.5
Cone Taper Angle
43
2.5.6
Scroll
43
2.5.3
2.6
WINDING WINDING MACHINES
44
2.7
CLASSIFICATION CLA SSIFICATION OF WINDING PRINCIPLES
45
2.7.1
Drum-Driven Winders
47
2.7.1.1 Cone Winding
49
2.7.1.2 Patterning
51
Contents
◾
vii
2.7.1.3 Path o Yarn on Cheese Cheese
51
2.7.1.4 Steps to Draw the Path o Yarn on Cheese Cheese
53
2.7.2
Spindle-Driven Winders
54
2.7.3
Step Precision Winder or Digicone Winder
58
2.8
GAIN
59
2.9
PIRN WINDING
61
2.10 CONDITIONS FOR UNIFORM PACKAGE BUILDING
63
2.10.1 Cheese Winding
63
2.10.2 Conditions for Uniform Cone Winding
65
2.10.2.1 Example o Uniorm Uniorm Cone W Winding inding 2.10.3 Grooves Grooves on Winding Drums
2.11 YARN TENSIONING
67 70
71
2.11.1 Types yp es of Tensioning Devices Dev ices
71
2.11.2 Relation between bet ween Input and Output Tensions in Multiplicative Multipl icative Tensioner
73
2.11.3 Tension Variation ari ation during duri ng Unwinding Unwindi ng from Cop Build Packages
74
2.12 2.1 2 YARN CLEARING
77
2.12.1 Objectives of Yarn Clearing
77
2.12.2 Principles of Measurement Measurement
78
2.12.3 Yarn Imperfections and Yarn Faults
80
2.12.3.1 Causes o Classimat Faults Faults
82
2.12.3.2 Settings o Yarn Clearing Channels Channels 2.12.4 Removal of Foreign Foreign and Coloured Fibres
84 85
2.13 SPLICING
87
2.14 SOME IMPORTANT ISSUES OF WINDING
88
2.14.1 Yarn Winding for Package Dyeing
88
2.14.2 Yarn Waxing ax ing
91
2.14.3 Defects in Wound Packages
91
2.14.4 Winding and Yarn Hairiness Hairi ness
92
NUMERICAL PROBLEMS REFERENCES
93 107
viii
◾
Contents
CHAPTER 3
◾
Warping
109
3.1 3.2
OBJECTIVES BEAM BEA M WARPING AND SECTIONAL SECTIONA L WARPING
109 109
3.3
COMPONENTS OF WARPING MACHINE
111
3.3.1
Types yp es of Creel
112 112
3.3.1.1 Single End Creel
112
3.3.1.2 Magazine Creel
112
3.3.1.3 ravelling or Swivelling Creel
113
Calculation Calcu lation for Warping Efficiency wit with h Different Creels
113
3.3.2
3.4 3.4 3.5 3.5
3.6
SECTION SECTIONAL AL WARPING STAGES STAGES OF WARPING
115 118
3.5.1
Creel
1188 11
3.5.2 3.5.3
Leasing Lea sing Expandable Expa ndable Reed
118 118 119
3.5.4
Beaming Beami ng
119
DEVELOPMENTS IN WARPING
121
3.6.1
Sample War arping ping Machine Machi ne
121
3.6.2
Smart Beam
122
NUMERICAL PROBLEMS
123
REFERENCES
126
CHAPTER 4
◾
Warp Sizing
1127 27
4.1 4.2
OBJECTIVES OBJECTI VES CHARACTERISTIC CHAR ACTERISTICSS OF SIZED YARN
4.3 4.4
IMPORTANT DEFINITIONS OF SIZING SIZING-WEA SIZING-WE AVING CURVE
128 129
4.5
SIZE ENCAPSULATION AND SIZE PENETRATION
129
4.6
SIZING MATERIALS
130
4.6.1
Desirable Properties of Sizing Materials
13 1322
4.6.2
Composition of Sizing Material
132 132
127
Contents
4.6.3
4.6.4
4.6.5
4.6.6
4.7
ix
Starch
1333 13
4.6.3.1 Chemical Structure o Starch Starch
133 133
4.6.3.2 Cooking o Starch Starch
135
4.6.3.33 Acid reatment 4.6.3. reatme nt o Starch Starch
136
Polyvinyl Polyv inyl Alcohol (PVA) (PVA)
137
4.6.4.1 Degree o Hydrolysis Hydrolysis
137
4.6.4.2 Degree o Polymerisation and Viscosity
140
Typical Recipe of Sizing
140
4.6.5.1 Carded Cotton Yarn arn
140
4.6.5.2 Combed Cotton Yarn arn
140
4.6.5.3 Polyester-Cotton Polyester-Cotton Blended Yarn arn
140
Steps for Preparing the Size Paste
141
SIZING MACHINE
141
4.7.1 4.7.2
Creel Zone Size Box Zone
142 145
4.7.2.1 Viscosity o Size Paste Paste
147
4.7.2.2 Squeezing Pressure Pressure
148
4.7.2.3 Hardness o op Squeeze Roll
150
4.7.2.4 Tickness o Synthetic Rubber on the op Roller
150
4.7.2.5 Position o Immersion Roller
150
4.7.2.6 Speed o Sizing
150
4.7.2.7 Percent Occupation and Equivalent Yarn Diameter
15 1511
4.7.2.8 Sizing Diagram Diagram
152 152
4.7.2.99 Crowning o op Rolle 4.7.2. Roller r
154
Drying Dry ing Zone
155 155
4.7.3.1 Methods o Drying
157
4.7.3.2 Splitting
159
Headstock Zone
161 161
4.7.3
4.7.4
4.8
◾
PRE-WETTING PRE-WET TING OF YARNS
161
x
Contents
◾
4.9 4.9 QUALITY QUALIT Y EVALUATION EVALUATION OF SIZED YARNS NUMERICAL PROBLEMS
162 164
REFERENCES
171
CHAPTER 5
5.1
5.2
5.3
◾
173
5.1.1
Draing Drai ng
1733 17
5.1.2
Liing Lii ng Plan
1744 17
TYPES TYPE S OF DRAFT DRA FT
174
5.2.1
Straight Straig ht Dra
17 1744
5.2.2
Pointed Dra
174 174
5.2.3
Skip Dra
1755 17
BASIC WEAVES
176
5.3.1
Plain Weave
1766 17
5.3.1.1 Warp Rib Rib
177
5.3.1.22 We Rib 5.3.1. Rib
178
5.3.1.3 Matt or Basket Weave eave
179
Twill wi ll Weave
1811 18
5.3.2.11 Pointed will 5.3.2.
18 1822
5.3.2.22 Angle o will 5.3.2.
183 183
Satin Sati n and Sateen Weaves
185
5.3.3.1 Six-End Regular Sateen Sateen
186
5.3.3.2 Rules or Making Satin or Sateen Weaves eaves
187
5.3.3
5.5
173
INTRODUCTION TO WEAVE DESIGN
5.3.2 5.3 .2
5.4
Weave Design
SOME FANCY WEAVES
188
5.4.1
Honeycomb
188
5.4.2
Mock Leno
188
5.4.3
Huck-a-Back Huck-a-Back
188
COMPUTER-AIDED DESIGN
192
5.6 WEAVE AND FABRIC PROPERTIES REFERENCES
192 193
Contents CHAPTER 6
6.1 6.2 6.3
◾
Shedding
◾
xi
195
PRIMARY PRIMA RY AND SECONDARY SECONDARY MOTIONS TRANSMISSION TR ANSMISSION OF MOTIONS IN SHUTTLE LOOM CAM CA M SHEDDING
195 196 198
6.3.1
Negative and Positive Positive Cams
199
6.3.2
Distinct Disti nct (Clear) (Clear) and Indistinct Indisti nct (Unclear (Unclear)) Shed
200
6.3.3
Li or row of Cam
201
6.3.4
Diameter of Reversing Rollers
203
6.3.5
Geometry of Shed
204
6.3.6
Calculation Calcu lation of Warp Strain Strai n during Shedding
205
6.3.7
Timing of Shedding
207
6.3.7.1 Early Shedding
208
6.3.7.2 Late Shedding
209
6.3.8
6.3.7.3 Eects o Shed iming iming and Backrest Position Position 210 Bending Bendi ng Factor 212
6.3.9
Heald Staggering
215 215
6.3.10 Heald Reversing Mechanism
21 2166
6.3.11 Positive Cam Shedding
218 218
6.3.11.1 Grooved Positive Positive Cam Cam
21 2188
6.3.11.2 Matched Positive Positive Cam Cam
219 219
6.3.12 Design of Shedding Cams
220
6.3.12.1 Design o Linear Cam Cam
221
6.3.12.2 Design o Simple Simple Harmonic Harmonic Motion Motion (SHM) Cam Cam
227
6.3.12.3 Advantages o SHM Cam over Linear Linear Cam Cam 232
6.4
DOBBY SHEDDING
233
6.4.1
Limitation Limitat ion of Cam Shedding
233
6.4.2
Keighley Dobby
234
6.4.2.1 System o Pegging
236
Cam Dobby
238
6.4.3
xii
Contents
◾
6.5
6.6
6.4.4
Positive Dobby
239
6.4.5
Modern Rotary Dobby
240
JACQUARD JACQUARD SHEDDING
241
6.5.1
Single-Li Single-Cylinder Single-Cyli nder (S (SLSC) LSC) Jacquard
241
6.5.2
Double-Li Double-Li Single-Cylinder Single-Cyli nder (DLSC) Jacquard
243
6.5.3
Double-Li Double-Li Double-Cylinder (DLDC (DLDC)) Jacquard
245
6.5.4
Jacquard Harness
246
6.5.5
Problems Problems in Jacquard Harness in Wide Looms
248
6.5.6
Pattern of Harness Tying
249
6.5.7
Electronic Jacquard
250
TYPES OF HEALD MOVEMENT MOVEMENT
252 252
6.6.1
Bottom Closed Shed
252
6.6.2
Semi-Open Shed
252
6.6.3 6.6.4
Centre Closed Shed Open Shed
253 254
6.7 DUAL-DIREC DUAL-DIRECTIONAL TIONAL SHEDDING NUMERICAL PROBLEMS REFERENCES CHAPTER 7
◾
Pickingg in Shuttle Loom Pickin
254 25 256 6 258
259 259
7.1 7.2
OBJECTIVES OBJECTI VES LOOM TIMING
7.3
CLASSIFICATION CLA SSIFICATION OF SHUTTLE PICKING MECHANISM 261 261
7.3.1
7.3.2
259 259 259 25 9
Cone Over-Pick Over-Pick Mechanism
261
7.3.1.1 Adjustments or Strength and iming iming o Over-Pick Mechanism Mechanism
262
Cone UnderUnder-Pick Pick Mechanism
264
7.3.2.1 Adjustments or Strength and iming iming o Under-Pick Mechanism Mechanism
265
7.3.2.2 Parallel Pick Pick
266
7.3.2.3 Link Pick Pick
266
7.3.2.4 Side Lever Under-Pick Mechanism Mechanism
268
Contents
◾
xiii
7.4 7.4
CATAPUL CATAPULT T EFFECT
269
7.5
SHUTTLE VELOCITY, VELOCITY, LOOM SPEED AND PICKING POWER
269
7.6
7.7
7.5.1
Relation between Shuttle Velocity and Loom Speed 269
7.5.2
Power Power Required for Picking
272
NOMINAL AND ACTUAL DISPLACEMENT OF SHUTTLE
273
7.6.1
275
Nominal Movement Movement in Straight Straig ht Line
SHUTTLE CHECKING
277
7.7.1
Mechanism of Shuttle Checking
277
7.7.2
A Simplified eoretical Model of Shuttle Checking 278
7.7.3
Checking by the Action of Picker
NUMERICAL PROBLEMS REFERENCES
281
284 291
Pickingg in Shuttleless Looms Pickin
293 293
8.1
LIMITATIONS LIMITATIONS OF SHUTTLE LOOM
293 293
8.2
PROJECTILE PICKING SYSTEM
29 295 5
8.2.1
Torsion of a Circular Circu lar Rod
295
8.2.2
Principle Pri nciple of Torsion Rod Picking Pick ing Mechan Mechanism ism
297
8.2.3
Acceleration Acceleration and Deceleration of Picker and Projectile
299
Hypothetical Hypothetica l Velocity Profile of Picker
301
8.2.4.1 Uniorm Uniorm Acceleration Acceleration
302
8.2.4.2 Non-Uniorm Non-Uniorm Acceleration Acceleration
303
8.2.5
Sequence of We Insertion Insert ion in Projectile Loom
306
8.2.6
Loom Timing
309
8.2.7
Beat-Up Mechanism Mechan ism
310
AIR-JET PICKING SYSTEM
312
8.3.1
Bernoulli Bernou lli’s ’s eorem
31 3133
8.3.2
Fluid Drag
315
8.3.3
Velocity elocit y and Acceleration Accelerat ion of Pick
316 316
CHAPTER 8
◾
8.2.4
8.3
xiv
◾
Contents
8.3.4
Devices to Control the Air Flow
317
8.3.4.1 Guide Plates Plates
317
8.3.4.2 Conusor
317
8.3.4.3 Profle Reed
319
Relay Nozzles
320
8.3.5.1 ypes o Relay Nozzles Nozzles
323
8.3.6
Design of Main Nozzle
323
8.3.7
We Storage Systems
325
8.3.8
Loom Timing
326
8.3.9
Effect of Yarn Characteristics Characterist ics on Yarn Velocity
327
8.3.9.11 Yarn Count 8.3.9.
327
8.3.9.2 Yarn Hairiness Hairiness
328
8.3.9.3 Yarn Bulk Bulk
328
8.3.9. 4 Yarn wist 8.3.9.4 wis t 8.3.9.5 Denier per Filament
328 328
8.3.5
8.4
8.5
8.3.10 Air Index
328
8.3.11 Tension Profile of We Yarn
330
8.3.12 New Features in Air-Jet Looms
331 331
8.3.12.1 Programmable Speed Control
331 331
8.3.12.2 Individual Control o Relay N Nozzles ozzles
332 332
8.3.12.3 Adaptive Control System System
332 332
WATER-JET PICKING SYSTEM
335 335
8.4.1 8.4.2
Water Quality Qual ity Water Consumption Consu mption
336 337
8.4.3
Loom Timing
33 3377
RAPIER RA PIER PICKING SYSTEM
338 338
8.5.1
Classification of Rapier Picking System
339 339
8.5.2
Displacement, Displacement, Velocity and Accelera Acceleration tion Profiles of Rapier
342
8.5.2.1
Displacement
342
8.5.2.2
Velocity
343
8.5.2.3 Acceleration Acceleration
344
Contents
◾
xv
8.5.3
Tip Transfer or Dewas System
345
8.5.4
Multicolour Multicolour We Selection
346
8.6 SELVEDGE SELVEDGE FORMA FORM ATION IN SHUTTLELESS LOOMS 8.7 MULTIPHASE MULTIPHASE WEAVING NUMERICAL PROBLEMS REFERENCES CHAPTER 9
Beat-Up
◾
347 347 348 351 358
359
9.1
OBJECTIVES OBJECTI VES
359 35 9
9.2
SLEY MOTION
359 35 9
9.2.1
Sley Displacement, Displace ment, Velocity elocit y and Accelerat Acceleration ion
359
9.2.2
Sley Eccentricity
366
9.2.2.1 Calculation Related to Sley Eccentricity
367
9.2.2.2 Eect o Sley Eccentricity
369
9.3 9.4 9.5
FORCE, TORQUE AND POWER REQUIRED TO DRIVE THE SLEY ANALYSIS ANALYSIS OF MOTIONS OF VARIOUS POINTS ON THE SLEY
369 372
WEAVING RESISTANCE
375
9.5.1
Cloth Fell Position Position and Pick Spacing
377
9.5.2
Bumping
379
9.6 FACTORS INFLUENCING INFLUENCING THE BEAT-UP BEAT-UP FORCE 9.7 TEMPLE NUMERICAL PROBLEMS
381 381 383 384
REFERENCES
390
CHAPTER 1 10 0
◾
Secondaryy and Auxiliary Secondar Auxiliary Motions
10.1 TAKE-UP MOTION
391 391 391 391
10.1.1 Objectives
3911 39
10.1.2 Classification
391 391
10.1.2.1 Negative ake-Up ake-Up
392
10.1.2.2 Positive ake-Up ake-Up
393
10.1.3 Five-Wheel Take-Up ake -Up
393
xvi
Contents
◾
10.1.4 Seven-Wheel Take-Up
394
10.1.4.1 Case I: One ooth ooth o One Gear Is Faulty
395
10.1.4.2 Case II: All eeth eeth o Any One Gear Are Faulty
398
10.1.4.3 Case III: Any Any One Gear Is Eccentric Eccentric
398
10.1.5 Shirley Take-Up
10.2 LET-OFF LET-OFF MOTION
399
400
10.2.1 Objectives
400
10.2.2 Classification of Let-Off
401
10.2.2.1 Negative Let-O
401
10.2.2.2 Semi-Positive Let-O
404
10.2.2.3 Positive Let-O
406
10.3 AUXILIARY AUXILIARY OR STOP-MOTIONS 10.3.1 Warp Protecting Motion 10.3.1.1 Fast-Reed Warp Warp Protecting Motion Motion
407 408 408
10.3.1.2 Loose-Reed Warp Warp Protecting Motion Motion
408
10.3.1.3 Electromagnetic Warp Warp Protecting Motion Motion
409
10.3.2 War arp p Stop-Motion
410
10.3.3 We Stop-Motion
412
10.3.3.11 Side We 10.3.3. We Fork Fork Motion Motion
412
10.3.3.22 Centre We 10.3.3. We Fork Motion Motion
41 4155
NUMERICAL NUME RICAL PROBLEMS PROB LEMS
415
REFERENCES
421
INDEX, 423
Preface
T
fabric through weaving is as old as human civilisation. Why should students of the twenty-first century show interest in such an old technology? Well, in ancient times, pigeons were used as messengers. en came postmen, who delivered letters from different countries to our abode. And today, ‘communication engineering’ has become one of the most vibrant and sought-aer engineering branches. erefore, as far as interest creation is concerned ‘how you do’ is probably more important than tha n ‘what you do’. do’. In the t he same note, the t he objective of
weaving has stil s tilll remained tthe he same: to produce fabrics. However However, the way of producing fabrics has transformed in the last three centuries. With the advancementt in machine design, electronics advancemen elect ronics and automation, automation, weaving has become a very sophisticated s ophisticated technology. e objective of this book is to introduce the basic concepts of woven fabric manufacturing to the undergraduate students of textile engineering. Other popular fabric manufacturing technologies like knitting, nonwoven, and braiding are not included in this book. e book covers the weaving technology based only on scientific and engineering engi neering approach approaches. es. e author has attempted to introduce the fundamental aspects of weaving preparatory and weaving assuming that the students have knowledge of high-school mathematics and science. Some mundane process descripdesc riptions which require memorising have been deliberately avoided. is pithy book does not cover industrial practices of weaving. It essentially covers the ‘vital few’ and not the ‘trivial many’. e content has been designed to create interest among students to hone their analyt ana lytical ical abilities. abilities . e author author has con convict viction ion that aer reading thiss book, studen thi students ts wi will ll be able to understand and analyse the preparatory processes of weaving such as winding, warping and sizing. ey will also be able to analyse various mechanisms of shuttle and shuttleless looms such as shedding, picking, beat-up, beat-up, ta take-up ke-up and let-off. let-off. xvii
xviii
◾
Preace
Most of the mathematical equations presented in this book have been derived from first principles so that the readers can comprehend them better and understand their implications. Topics such as shedding cam design and sley kinematics have been discussed in detail as students find it interesting to study these engineering aspects of weaving technology. Each contains solved numerical problems to enhance clarity of chapter the readers aboutsome the topic discussed. Many complex situations of weaving preparatory and weaving have been explained with simple hypothetical analogies. ese analogies may not always represent the prevailing complexities; however, however, tthey hey are essential es sential for concept buildi building. ng. ere are a few topics which should have been discussed in greater depth. e author feels that water-jet weaving is one of those and wishes w ishes to improvee on this improv th is topic in subsequent editions. In spite of best efforts, there t here might be some inadvertent mistakes in the book. It will be appreciated if the readers can spot these errors and bring it to the t he author’s author’s notice. Abhijit Majumdar
Acknowledgements
T
gratitude to Prof. Prabir Kumar Banerjee and Prof. Vijay Kumar Kothari of Indian Institute of Technology Delhi for introducing him to the world of fabric manufacturing. He is highly obliged to Dr. Abhijit Biswas of the Government College of Engineering and Textile Technology, Berhampore, India, and Prof. M. Madhusoothanan of Anna University, Chennai, India, for providing valuable comments and suggestions sug gestions to iimpro mprove ve the contents contents of the book. e author is also thankful to Prof. Rabi Chattopadhyay of IIT Delhi for providing inspiration to pursue this initiative. A special mention must be made of Dr. Anindya Ghosh and Dr. Tarit Guha, of Government College of Engineering and Textile Technology, Berhampore, India, with whom the author had endless discussions and exchanges while preparing this manuscript. anks also to Khashti Pujari and Animesh Laha for their help in preparing some of of the diagrams diag rams of this th is book. e author gratefully acknowledges permissions accorded by M/S Prashant Industries, India, M/S Uster Technologies, Uster, Switzerland, CRC Press in Boca Raton, Florida, Elsevier, Amsterdam, Netherlands, and e Textile Institute in Manchester, United Kingdom for the use of copyrighted figures in this book. Finally Final ly,, the author thanks tha nks Dr. Gagandeep Singh of CRC Press wholeheartedly hearted ly for his patience and perseverance in following following up preparation of the manuscript.
xix xi x
Author Abhijit Majumdar obtained bachelor’s degree from Calcutta University in 1995 with first class first position in Textile Technology program. He acquired master’s degree in textile engineering from Indian Institute of Technology (IIT) Delhi in 1997 and doctorate in engineering from Jadavpur University, Kolkata, in 2006. He also holds an MBA from IIT Delhi with specialization in operations management. He worked in companies such as Voltas Voltas Limited Li mited aand nd V Vardhman ardhman Grou Group p before joining joining academia. academia . He taught in Government College of Engineering
and Textile Technology, Berhampore, West Bengal, India, between 1999 and 2007. He joined IIT Delhi as assistant professor in 2007. At present, he is working as associate professor in Textile Engineering Group. His research areas include protective textiles, so computing applications and operations and supply chain management. He has completed three research projects funded by the Department of Science and Technology (DST) and Council for Scientific and Industrial Research (CSIR), India. He has published 70 research papers in international refereed journals and guided four PhD students. He has edited two books published by Woodhead Publisher, U.K., and authored one monograph (extile (extile Progress)) published by Taylor & Francis Group. Progress He is the associate editor of the Journal the Journal o the Institution o Engineers (India)) Series (India Ser ies E (Chemical and extile Engineering) Engineering ) published by Springer. He is a recipient of Outstanding Young Faculty Fellowship of IIT Delhi (2009–2014) and the Teaching Excellence Award (2015) of IIT Delhi.
xxii xx
CHAPTER
1
Introduction to Fabric Manufacturing
1.1 FABRIC MANUF MANUFACTURIN ACTURING G TECHN TECHNOLOGIES OLOGIES Texti extile leof fabrics generally two-dimensional t wo-dimensional flexible materials made by interlacing yarnsare or intermeshing of loops with wit h tthe he exception of nonwov non wovens ens and braids. Fabric manufacturing manufacturi ng is one of the t he four major stages (fibre (fibre production, production, yarn manufacturing, fabric manufacturing and textile chemical processing) of textile value chain. Most of the apparel fabrics are manufactured by weaving, though knitting is catching up or even moving ahead very fast, especially in the sportswear segment. Natural fibres in general and cotton fibre in particular are the most popular raw material for woven fabrics intended for apparel use. Staple fibres are converted into spun yarns by the use of a series of machines in the yarn manufacturing stage. Continuous filament yarns are oen texturised to impart spun yarn-like bulk and appearance. Textile fabrics are special materials as they are generally light-weight, flexible (easy to bend, shear and a nd tw twist), ist), mouldable, mouldable, permeable and strong. st rong. e four major technologies technologies of fabric manufacturing manufactu ring are as a s follows: 1. Weaving eavi ng 2. Knitting 3. Nonwoven 4. Braiding Figure 1.1 depicts depicts the fabrics produced produced by the t he four major technologies. technologies. 1
2
Principles o Woven Fabric Manuacturing
◾
(a)
( b)
(c)
(d)
FIGURE 1.1 Fabrics produced by different technologies. (a) Weaving, (b) knitting,
(c) nonwoven and (d) braiding. TABLE 1.1 Properties of Some Technical Fabrics Fabric ype
Filter fabrics Body armour fabrics Fabr Fabric icss as perf perfor orms ms for for com compos posit itee Kni nittte ted d com compress essio ion n ba bandages ges
Important Properties/Parameters Properties/Parameters
Pore size, pore size distribution Impact resistance, areal density, bending resistance Ten ensi sile le str stren ength gth and and ten tensi sile le mod modul ulus us Stret tretch chaabil iliity ty,, tten enssil ilee mod modul ulus us,, ccrree eep p
Fabric manufacturing may be preceded either by fibre production (in case of nonwoven) or by yarn manufacturing (in case of weaving, knitting knit ting and braidi braiding). ng). Fabrics Fabrics intended for for apparel use must fulfil ful fil multidimensional quality requirements in terms of drape, handle, crease recovery, tear strength, air permeability, thermal resistance and moisture vapour permeabilit p ermeabilityy. However However, looking at the t he unique properties and versatil versat ility ity of tex texti tile le fabric fabrics, s, they the y are now b being eing used in var various ious technitech nical applications where the requirements are altogether different. Some examples are given in Table 1.1.
1.2 WEAVING TECHNOLOGY TECHNOLOGY Weaving is one of the oldest technologies of human civilisation and has been in existence ex istence since 7000 BC. e weaving technology leapfrogged leapfrogged with the invention of power loom by Edmund Cartwright in 1785 (Lord and Mohamed, 1982) and is considered to be one of the key inventions of the Industrial Industr ial Revolution Re volution (17 (1760–1840) 60–1840).. Weaving Weaving is the t he most popula popularr method of fabric manufacturing and is generally done by interlacing two orthogonal sets of yarns – warp (singular: end) and we (singular: (singular: pick) – in a regular and recurring pattern. Actual weaving process is preceded by yarn preparation processes, processes, namely winding, warping, sizing, drawing and denting. Winding converts the smaller ringframe packages to bigger cheeses or cones while removing the objectionable yarn faults. Pirn winding is
Introduction to Fabric Manuacturing
(a)
(b) (b
(c)
◾
3
(d)
FIGURE 1.2 Types of yarn packages. (a) Ringframe bobbin or cop, (b) cone,
(c) cheese and (d) pirn.
performed to supply the we yarns in shuttle looms. Figure 1.2 shows various yarn packages used used in text textile ile operations (from (from le to right: ringf ringframe rame bobbin or cop, cone, cheese and pirn). Warping Warping is done to prepare a warper’s wa rper’s beam which which contains a large number of parallel warp yarns or ends in a double flanged beam. Sizing is the process of applying a protective coating on the warp yarns so that they can withstand repeated abrasion, stress, strain and flexing during the weaving process. Winding, warping and sizing are known as ‘preparatory to weaving’. en the warp yarns are drawn through the heald wires and reed dents in drawing and denting operations, respectively. Finally the fabric is manufactured on looms which perform several operations following a predefined sequence so that there is interlacement between warp and we yarns. e general steps of woven fabric manufacturing are shown in Figure 1.3.
1.2.1 .2.1 Type ypess o Looms Hand loom: loom: is is mainly used in the unorganised sector. Operations such as shedding sheddi ng and picking aare re done by using manual power. power. is is one of the major sources of employment generation in rural areas of India and many other countries. Power loom (non-automatic): All the operations of non-automatic power loom are driven by motor except pirn changing. ey have very
4
Principles o Woven Fabric Manuacturing
◾
Winding
Warping
Sizing
Drawing and denting
Weaving
FIGURE 1.3 Steps of woven fabric manufacturing.
limited use for the production of normal woven fabrics, specially in modern industries. However, they are sometimes used for weaving industriall fabrics from very coarse we (Marks and Robinson, 197 industria 1976; 6; Lord and Mohamed, 1982). Automati Autom aticc loom loom: In this power loom, the exhausted pirn is replenished by the full f ull one without wit hout stoppage. stoppage. is is possible only in under-pick under-pick system. Multiphase loom: loom: Multiple sheds can be formed simultaneously in this looms and thus productivity can be increased by a great extent. However How ever,, it has failed fa iled to attain atta in commercial success. Shuttleless loom: loom: We is carried by projectiles, rapiers or fluids in case of shuttleless looms. e rate of fabric production is much higher for these looms. Besides, the quality of products is also better, and the product range is much broader compared to those of power looms. Most of the modern mills are equipped with different types of shuttleless looms based on the product range. Circular loom: loom: Tubular fabrics such as hosepipes and sacks are manufactured by circular looms. Narrow loom loom:: ese looms are also known as needle looms and are used to manufacture narrow-width fabrics such as tapes, webbings, ribbons and zipper tapes .
Introduction to Fabric Manuacturing
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5
Back rest
Cloth fell
Woven fabric
Warp Heald Weaver’s beam
Cloth roll
FIGURE 1.4 Basic loom components. (Reprinted from Weaving: Conversion o
Yarn to Fabric, Fabric, 2nd edn., Lord, P.R. and Mohamed, M.H, Copyright 1982, with permission from Elsevier.)
1.2.2 Primary Motions
Figure 1.4 shows some basic components of a loom. e longitudinal or warp yarns are a re supplied by weaver’ weaver’ss beam positioned positioned at the back of tthe he loom. e produced fabric is wound over the cloth roller positioned at the front of the loom. For fabric manufacturing, three primary motions are required: shedding, picking picki ng and beat-up. beat-up. 1.2.2.1 Shedding Shedding is the process by which the warp sheet is divided into two groups so that a clear passage is created for the we yarn or for the we-carrying
device to or pass through group(ifofthey yarns moves in position) the upward direction stays in theit.upOne position areeither already in that as shown in Figure 1.5, thus forming the top shed line. Another group of yarns either moves in the downward direction or stays in the down position (if they are already al ready in that position), position), thus forming the bottom shed line. Except for jacquard shedding, warp yarns are not controlled individually during the shedding operation. Healds are used to control a large number of warp yarns. e heald frame, which could be either metallic or wooden, carries a large number of metallic wires known as heald wires (Figure 1.6). Each heald wire has a hole, called heald eye, at the middle of its length. length. e warp yarn ya rn actual actually ly passes through the heald eye. erefore, as the heald moves, all erefore, al l the warp yarns ya rns which are a re controlled controlled by that head also move. e upward and downward movements of healds
6
Principles o Woven Fabric Manuacturing
◾
Top shed line
Bottom shed line
FIGURE 1.5 Shedding.
Heald frame
Heald eye Heald wire
FIGURE 1.6 Heald.
are controlled either by cam or by dobby shedding mechanisms mechani sms and associated heald reversing mechanism. e movement of the healds is not continuous. Aer reaching the topmost or lowest positions, the healds, in general, remain stationary for some duration. is is known as ‘dwell’. In general, gene ral, the shed changes aer every pick, that is the insertion inser tion of we. 1.2.2.2 Picking e insertion insert ion of we or we-carr we-carrying ying device dev ice (shuttle, (shuttle, projecti projectile le or rapier rapier)) through the t he shed is known as picking. Based on the picki picking ng system, looms can be classified as follows.
• Shuttle loo loom: m: We We package or pirn pirn is carried by the wooden wooden shuttle. • Projectile loo loom: m: We We is carr carried ied by by metallic or composite composite projectile. projectile.
Introduction to Fabric Manuacturing
◾
7
FIGURE 1.7 Shuttle, rapier heads and a nd projectile (from top to bottom) bot tom)..
• Air Airjet jet loom: loom: We We is inserted by jet of co compressed mpressed air. • Waterjet loom: We is inserte ins erted d by water jet. • Rapier loom: We is inserted by flexible or rigid rapiers. Figure 1.7 shows some we-carrying devices. With the exception exce ption of shuttle loom, we is always inserted inser ted from only one side of the loom. e timing of picking is extremely important, especially in case cas e of shuttle loom. e shuttle should enter the shed and leave the shed when the shed is sufficiently open (Figure 1.8). 1.8). Otherwis Other wise, e, the movement o off
Shuttle
FIGURE 1.8 Picking.
8
Principles o Woven Fabric Manuacturing
◾
Pick pushed by reed
FIGURE 1.9 Beat-up.
the shuttle will wil l be obstructed by the warp yarns, because of which the warp yarns may break or the shuttle may get trapped inside the shed, which may cause damage to reed, shuttle shuttle and war warp p yarns. 1.2.2.3 Beat-Up Beat-up is the action by which the newly inserted we yarn or pick is pushed up to the cloth fell (Figure 1.9). Cloth fell is the boundary up to which the t he fabric has been woven. e loom component component responsibl responsiblee for the beat-up is called ‘reed’. e reed, which is like a metallic comb, can have different count. For example, 80s Stockport reed has 80 dents in 2 inches. Generally, one or two warp yarns are passed through a single dent, and these are a re called cal led ‘one ‘one in a dent’ or ‘t ‘two wo in a dent’, respectively. respectively. Reed is carried by the sley, which sways forward and backward due to the crank-
connecting rod mechanism. is by system is known as which crank isbeat-up. shuttleless looms, beat-up is done cam mechanism, known In as cam beatbeat-up. up. Generally, Generally, one beat-up beat-up is done done aer the iinsertion nsertion of one pick.
1.2.3 Secondary Motions For uninterrupted manufacturing of fabrics, two secondary motions are required. ese are take-up and let-off. Take-up motion winds the newly formed fabric on the cloth roller either continuously or intermittently aer the beat be at-up -up.. e take-up speed also a lso determines the t he picks/ picks/cm cm value va lue in the t he fabric at loom state. state . As the t he take-up ta ke-up motion moti on winds wi nds the t he newly formed fabric, tension in the warp sheet increases. To compensate this, the weaver’s beam is rotated by the let-off mechanism so that adequate length of warp is released.
Introduction to Fabric Manuacturing
◾
9
1.2.4 Auxiliary Auxiliary Motions Auxiliary motions are mainly related to the activation of stop motions in case of any malfunctioning such as warp breakage, we breakage or shuttle trapping within the shed. e major auxiliary motions are as follows: • Warp stop motion (in case of warp breakage) breakage) • We stop motion (in case of we break breakage) age) • Warp protector motion (in case of shuttle shuttle trapping inside the shed)
1.2.5 Some Basic Defnitions 1.2.5.1 Yarn Coun 1.2.5.1 Count t Yarn count represents the coarseness or fineness of yarns. There are two distinct principles to express the yarn count.
1. Direct Direc t systems syst ems (exa example: mple: Tex, Denier) 2. Indi Indirect rect systems (example: new English, i.e. i.e. Ne, Metric, i.e. Nm Nm)) Direct systems revolve around expressing the mass of yarn per unit u nit length. In contrast, indirect system s ystem expresses the length lengt h of yarn per unit mass. For example, 10 tex yarn implies that a piece of 1000 m long yarn will have a mass of 10 g. Similarly Simi larly,, for 1100 denier, denier, a piece of 9000 900 0 m long yarn w will ill have a mass of 10 g. Denier is popularly popularly used to express tthe he fineness of synthetic fibres and filaments. A 10 denier yarn is finer than a 10 tex yarn as for the same the length is nine times for Onmass, the other ha nd, 10 hand, N Nee implies that t hatthe a 1-pound 1-former. pound yarn will w ill have a length lengt h of 10 × 840 yards. As the Ne value increases (say from 10 to 20 Ne), the yarn becomes finer fi ner.. Table 1.2 shows some popular yarn count systems. TABLE 1.2 Direct and Indirect Systems of Yarn Count ype
Name
Unit of Mass
Unit of Length
Direct
Tex Denier
Gram Gram
1000 m 9000 m
Indirect
Ne Metric
Pound Kilogram
Hank (840 yards) Kilometre
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Principles o Woven Fabric Manuacturing
◾
e following conversion formula is used to change the yarn count from one system to another.
Tex =
590.5 5315 , Denier = 9 ´ Tex and Denier = Ne Ne
1.2.5.2 Packing Factor or Packing Coefcient Packing factor or packing coefficient represents the extent of closeness of fibres within the yarn structure. For the same yarn linear density, if the fibres are closely packed, then yarn diameter will be less. is happens when a spun yarn is manufactured with high level of twist. Figure 1.10 shows the close packing of circular fibres in a yarn. Packing factor is expressed as follows:
=
Packing factor
Cumulative area of all fibres Area of yarn cross ross section
FIGURE 1.10 1.10 Close packing of circular fibres. fibres.
Yarn density =
Fibre density
Introduction to Fabric Manuacturing
◾
11
A
60° B
C
FIGURE 1.11 Repeat unit of close packing.
Figure 1.11triangle depicts ABC the repeat unit of closely circular fibres. e equilateral actually indicates thepacked repeat area. If fibre radius is r , then each side of the triangle ABC is having a length of 2r 2r . erefore,
The area of tri triangle ABC
=
3 4
( 2r f )
2
=
3r f 2
The to tottal are area of fibr fibree insi inside de th thee tri trian anggle ABC = 3 ´
1 2 pr f 6
p =
2
r f 2
So max maximu imum m possibl possiblee pac packi king ng fact factor or
=
Total tal are area of fib fibre insi insid de tria triangle n gle AB ABC C Area of tri trian anggle ABC
=
(p / 2)r f 2 2 f
3r
=
0.91
For spun yarns, packing factor generally lies between 0.55 and 0.65. Yarns with lower packing factor are expected to be bulkier and soer. ey can cause higher fabric cover for same fabric construction parameters.
12
Principles o Woven Fabric Manuacturing
◾
1.2.5.3 Warp and Wet Wet A group of longitudinal yarns in a woven fabric (or on a loom) is called warp. A single warp wa rp is called ‘end’. ‘end’. A group of transverse yarns ya rns in a woven fabric is called we. A single we is called ‘pick’. 1.2.5.4 Crimp Once the warp and we are interlaced, both of them assume wavy or sinusoidal-like path. us the length of the yarn becomes more than that of the fabric within which the former is constrained. Crimp is a measure of the degree of waviness present in the yarns inside a woven fabric. Contraction is another measure of yarn waviness. e expressions of crimp and contraction are given g iven below. below. Leng Le ngth th of yarn yarn - Le Leng ngth th of fa fabr bric ic 100 ´ 100 Length of fabric
Crimp % =
Contraction % =
Leng Le ngth th o off ya yarn rn - Le Leng ngth th o off fa fabr bric ic ´ 100 Length of yarn rn
(1.1)
(1.2)
If the warp crimp is 10%, then the straightened length of an end, unravelled from the 1 m long fabric, will be 1.1 m. 1.2.5.5 Fractional Cover and Cover Factor Factor Fractional cover is the ratio of the area covered by the yarns to the total area of the fabric. If diameter of warp yarn is d 1 inch and spacing, that is
gap between the two consecutive ends is p is p1 inch, then fractional cover for warp (k (k1) is d 1/ p p1. Now, for cotton yarns, having packing factor of 0.6, the relationship between yarn diameter (d (d ) in inch i nch and yarn count (Ne) is as follows:
d
=
1 28 Ne
(1.3)
e relationship between end spacing ( p1) and ends per inch (n (n1) is as follows:
n 1
=
1 p 1
(1.4)
Introduction to Fabric Manuacturing
◾
13
Aer rearranging, the following expression is obtained for fractional cover for warp. k 1
=
n 1 28 Ne1
(1.5)
where Ne1 is the warp count. Similarly Simi larly,, the ex expression pression for for fractional fract ional cover for for we ((kk2) is as follows: k 2
=
n 2 28 Ne2
(1.6)
where n2 is the picks per inch Ne2 is the we count Cover factor is obtained by multiplying fractional cover with 28.
Warp cover factor = kw = 28 ´ k 1
n 1
=
Ne1
(1.7)
Fabric cover is a very important parameter as it influences the following properties of wove woven n fabrics: • Air permeability permeability • Moisture vapour permeability • Ultraviolet o orr any other ty types pes of of radiation protection Figure 1.12 1.12 shows two fabrics with wit h low and high cover factors. 1.2.5.6 Porosity Porosity Por osity is a measure of presence of void or air inside tthe he fabric or fibrous assemblies. It indicates the percentage of volume of fabric that has been occupied by the air. If there is no porosity, then the densities of the fibre and fabric will be the same. However, in most of the fabrics there will be some air pockets which will contribute to the volume and not to the
mass. For example, woven woven and knitted fabrics can c an have typical typica l porosity of 70%–80% and 80%–90%, respectively.
14
Principles o Woven Fabric Manuacturing
◾
(a)
( b)
FIGURE 1.12 1.12 Fabrics with (a) low and (b) high cover factors.
Let us consider the following: Fabric areal density or gram gra m per square meter (GSM) = G g/m2 ickness of fabric = m m Density of fibre = ρ g/m3 Porosity (%) = P Thee ma Th mass ss o off 1 m3 fab fabri ricc w wil illl b bee
=
Areal density Thickness
=
G g T
Since the mass of fabric is only being contributed by the fibre, the mass of 1 m3 fabric will wi ll be = Volume Volume occupied by the fibre in 1 m3 fabric × density æ P ö of fibre = è ç 1 - 100 ø÷ ´ r g .
æ P ö ´ r = G ÷ T è 1000 ø
Therefore, ç 1 -
æ G è T ´ r
So porosity ( % ) = ç 1 -
ö ÷ ´100 ø
(1.8)
Porosity influences the thermal conductivity of the fabric or fibrous assemblies. Air is a poor conductor of heat, and its thermal conductivity (K air ) is 0.025 W/m K. On the other hand, thermal conductivity of cotton
Introduction to Fabric Manuacturing
◾
15
fibre is around 0.24 W/m K, which is approximately 10 times more than that of air. e thermal conductivity of a fabric having porosity of P can can be expressed as a s follows:
æ
Thermal conductivity of fabric = ç 1 -
P P ö K ´ K air r (1.9) ÷ fibre +
100 è 100 ø erefore, erefo re, higher porosity implies i mplies lower lower thermal therma l conductiv conductivity ity of tthe he fabric and vice versa.
1.2.5.7 Areal Density Areal density is expressed ex pressed by the mass of the fabric per unit area. In most of the cases, cases , the mass is expressed in gram (g) and area is expressed in square meter (m2). erefore, the unit becomes g/m 2, which is popularly called GSM. Areal density of the fabric will wi ll depend on the following following parameters: para meters:
• Warp ar p yarn yar n count (tex): 1 • We yarn yar n count (tex): (tex): 2 • Ends per unit length (EPcm): (EPcm): N 1 • Picks per unit length (PP (PPcm) cm):: N 2 • Crimp % in warp: C 1 • Crimp % in we: C 2 Let us consider consider a piece of fabric having dimensions di mensions of of 1 m × 1 m as shown in Figure 1.13. e number of ends per cm is N 1. So, the total number of ends in the given fabric is 100N 100N 1. e projected length of one end is 1 m when incorporated in the fabric. Ho However wever,, the end has some crimp in it. erefore,
æ è
Straightened length of one end = 1´ ç 1 +
C 1 ö ÷m 100 ø
Tota To tall len lengt gth ho off eend ndss ( wa warp rp) tal nu num mbe berr of end ndss ´ str straig aight hteened length of one end = Total
= 100N 1 ´ çæ 1 + C 1 ÷ö m. è 100 ø
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Principles o Woven Fabric Manuacturing
◾
m 1
1m
FIGURE 1.13 One square meter of fabric.
Mass of warp yarns(g) =
Total length of ends in m
´ tex of warp
1000
æ C ö 100N 1 ´ ç 1 + 1 ÷ è 100 ø ´T = N 1T1 æ 1 + C 1 ö = 1 ç ÷ 1000 10 è 100 ø
Similarly
The mass of weft yarns (g) =
So
N 2T2 æ C 2 ö ç1 + ÷ 10 è 100 ø
Total mass of the fabric(g c(g)) = Mass of warp yarns(g) s(g) + Mass of weft yarns ((g) g)
=
N 1T1 æ C1 ö N 2T2 æ C 2 ö 1+ 1+ + ç ÷ ç ÷ 10 è 100 ø 10 è 100 ø
=
1 é æ C 1 ö æ C 2 ö ù N T 1 N T + + 1 1 2 2 ç ÷ ç1 + ÷ú 10 êë 100 0 è ø è 100 ø û
So Areal density of fabric or GSM =
1 é
æ C 2 ö ù æ C 1 ö N T 1 N T + + 2 2 ç1 + ÷ú ÷ ê 1 1ç 10 ë è 100 ø û è 100 ø (1.10)
Introduction to Fabric Manuacturing
◾
17
TABLE 1.3 Cover, Areal Density, ickness and Porosity Values of Fabrics Cover (%)
Areal Density (g/m2)
Tickness (mm)
Porosity Porosity (%)
Polyester-cotton Polyester-cotton 100% cotton
78.4 84.6 88.2
122 136 135
0.298 0.307 0.402
72.9 70.7 77.8
110000% % cco otttto on n
9925..92
115751
00..442442
7754..84
Fabric ype
Table 1.3 presents cover, areal density, thickness and porosity values of some woven woven fabrics made from spun yarns. ya rns.
1.3 KNITTING KNITT ING TECHNOLOGY Knitting is a process of fabric formation by producing series of intermeshed loops. Loops are the building blocks of knitted fabrics (Figure 1.14). e upper part of the loop is called ‘head’, whereas the two sides are called ‘legs’. e intermeshing of two loops happens through the ‘foot’. In general, the knitted fabrics are more stretchable than the t he woven woven fabrics. e open structure struct ure of knitted fabrics also facilitates better moisture vapour transmission, making it suitable for sports garments and high-activity clothing. Besides, the knitted fabrics have more porosity than the woven fabrics. erefore, knitted fabrics
Head
Legs
Foot
FIGURE 1.14 1.14 A knitted loop.
18
Principles o Woven Fabric Manuacturing
◾
can trap more air, resulting resulting in lower thermal conductiv conductivity ity and higher therma thermall resistance. ere are two types of knitting: warp knitting and we knitting.
1.3.1 Wet Knitting In we knitting loops are made by the supplied yarns across the width of the fabric (Figure 1.15a). We knitted fabric can be made even from one supply package. e we knitting machines are of two types: 1. Flatbed machine
a. Single bed
b. Double Double bed or V bed
2. Circular bed machine In flatbed machine, the needles do not perform any lateral movement. The axial movement of the needles, needed for loop formation, is actuated by a set of cams mounted on cam jacket which reciprocate laterally (exception: straight bar machines). In contrast, the cam jacketss are generally jacket genera lly stationar stat ionaryy in circula circ ularr kn knitt itting ing machine, machi ne, whereas the cylinder carrying the needles on its grooved surface rotates continuously to cause the upward and downward movement of needles. In many small-diameter circular we knitting machines, the cylinder may remain stationary while the cam jackets revolve. is is true for single feeder machines.
(a)
( b)
FIGURE 1.15 (a) We knitted fabric and (b) warp knitted fabric.
Introduction to Fabric Manuacturing
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19
1.3.2 Warp Knitting In warp knitting, loops are made from each warp yarn along the length of the fabric (Figure 1.15b). e yarns are supplied in the form of a sheet made by parallel warp yarns coming out from a single or multiple warp beams. e yarns are fed to the needles by guide bars which swing to and fro and a nd shog laterally. e loop formation mechanism is more complex for warp knitting knitti ng than that of we knitting.
1.3.3 Needle Irrespect ive of the knitting Irrespective knit ting technology, the machine element element which helps in loop formation is called needle. Latch, bearded and compound needles are used, depending on the type t ype of knitti k nitting ng machine. Latch needle (Figure 1.16 1.16)) is most popularly used in we we knitting knitt ing and Raschel warp knitting knit ting machine. e major components of a latch needle are as follows: • Hook • Latch • Latch spoon (cup)
Hook
Rivet
Latch Cup Stem
Butt
FIGURE 1.16 1.16 Latch needle.
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Principles o Woven Fabric Manuacturing
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• Stem • Butt Hook is the curved cur ved part of the t he needle which is responsible for loop loop formation. Latch is a tiny component that is riveted on the upper part of stem of the needle. Latch spoon (cup) is the tip of the latch which encloses the outer surface of the tip of the hook when the latch closes. e upward and downward movements of the needles during the loop formation are caused by a set of cams in we knitting and by movement of bars in warp knitting. e butt is actually the ‘follower’, and it is pressed against the cam to cause c ause movement movement of the needle.
1.3.4 Loop Formation in Knitting Knitt ing e sequence of loop formation is shown in Figure 1.17. When the needle moves up, the old loop forces the latch to open. When the old loop rests on the latch, the position is and called position in Figure 1.17). needle moves up further furt her the‘tuck’ old loop slides(1down the latch anden reststhe on the stem of the t he needle. is is cal called led the ‘clearing’ position ((22 in Figure Figu re 1.17 1.17). ). e needle attains its highest position at 3 in Figure 1.17. en it starts to descend and the hook catches the yarn. As the t he needle con continues tinues to descend, the yarn bends in the form of a loop (‘U’ shape). e old loop now helps close the latch by pushing it in upward direction so that the newly formed loop is about to be caught between the hook and latch (4 in Figure 1.17). e needle
3 4
2
1
FIGURE 1.17 Sequence of loop formation.
5 6
Introduction to Fabric Manuacturing
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21
continues to descend and new loop is ‘cast on’ (5 in Figure 1.17) and finally ‘knocked over’ (6 in Figure 1.17) through the old one. Casting-off or knocking-over is the same phenomenon, executed in two different manners. For casting-off to take place, special knitting elements bodily push the old loop out, while in case of knocking-over, help of sinkers or verges is necessaryy to prevent sar prevent the old loop from moving down with the needle.
1.3.5 Course and Wale Wale e horizontal row of loops is called cal led ‘course’ ‘course’.. e vertical vertica l column of loops is called ca lled ‘wale’ (Figure 1. 1.18 18). ). e wales per inch i nch ((wpi wpi)) and courses per inch (cpi cpi)) of knitted fabrics are analogous to ends per inch (epi (epi)) and picks per inch ( ppi ppi)) of woven fabrics. For a fully relaxed knitted fabric, the wpi wpi and and cpi values cpi values are determined by the loop length. Smaller loop length leads to higher values of wpi wpi and and cpi cpi.. As a result, resu lt, the stitch st itch density or loop density, density, which is a product product of wpi wpi and and cpi cpi,, also increases with w ith the reduction in loop length. e ratio of cpi cpi and and wpi wpi is is known as loop shape factor. For a fully relaxed single jersey fabric, the t he loop shape factor is around 1.3. Let the loop length be l inch. inch. So
Wales per inch ( wpi )
k w l =
FIGURE 1.18 1.18 Course and wale.
and co urses per inch (cpi )
k c l =
(1.11)
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Principles o Woven Fabric Manuacturing
◾
erefore,
k Stitc titch h den densi sity ty (inch inch 2 ) = wpi ´ cpi = w l -
´
k c l
=
kw k c l 2
=
k s l 2
(1.12)
where kw, kc and ks are wale constant, course constant and stitch constant, respectively. ese constants are independent of yarn and machine variables. In a fully relaxed state, the values of these constants for worsted single jersey fabric f abric are 4.2 4.2,, 5.5 and a nd 23.1, 23.1, respectively. respectively.
1.3.6 Single Jersey and Double Jersey Fabrics Flatbed machines, as the name implies, have one or more beds for carrying the needles. Single bed machines produce plain or single jersey structure, whereas double bed machines produce rib (1 × 1, 2 × 2 etc.) and purl structures. Single jersey and double jersey (1 × 1 rib) structures are shown in Figure 1.19. 1.19. Double Double bed machines machi nes can also be b e employed employed to develop single jersey constructions. constr uctions. e needles on the two beds in i n a do double uble bed machine must be offset so that they do not collide with each other while forming the loops. In case of single jersey fabrics, all the heads of the loops either face the viewer or are a re away from the viewer. In Figure 1.19a, 1.19a, aall ll the heads of the loops are hidden from the viewer while whi le the feet are prominently visible, so it is the t he technical face side of the fabric (Banerjee, 201 2 015) 5).. e other side of the fabric is known as technical back.
(a)
( b)
FIGURE 1.19 (a) Single jersey and (b) double jersey (rib) structures.
Introduction to Fabric Manuacturing
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23
FIGURE 1.20 Inter Interlock lock structure. struc ture.
In case of rib (double jersey) fabrics, in some of the wales, heads of the loops face the viewer v iewer and vice versa (Figure 1.19b 1.19b), ), so there is no technical face or back in double jersey fabric. Single jersey fabrics tend to curl at tthe he edges. In general, double jersey fabrics are thicker t hicker and more stretchable in course direction than the single jersey fabrics. In circular single jersey knitting machine, only one set of needles are used on the cylinder c ylinder.. However However,, in circular rib knitting knitt ing machine, two sets of needles – cylinder and dial needles – are used. ey operate perpendicularly to each other. One set of needles (cylinder needles need les)) are ar arranged ranged on the surface of a grooved cylinder. Generally the cylinder is rotated and needles get the requisite movement from the stationary cam jackets. Another set of needles operate operate in horizontal plane and they are known as dial needles. Another important double jersey structure which is made on circular machines is known k nown as interlock. interlock. It is basically a combination of two rib structures as shown in Figure 1.20. e interlocking interlocking of two rib st structures ructures is responsible for for lower lower stretchability of interlock interlock fabrics as compar compared ed to tthe he original rib structure. struct ure. Interlock Interlock fabrics are generally heavy and demonstrate least porosity porosity among the three t hree knitted knit ted structures str uctures (single jersey, jersey, rib and a nd interl interlock) ock)..
1.3.7 Tightness Factor Tightness factor implies the relative tightness or looseness of a single jersey knitted kn itted fabric by indicating the t he ratio of fabric area covered covered by the yarn
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Principles o Woven Fabric Manuacturing
◾
1/wpi
i p c / 1
FIGURE 1.21 Repeat unit of a knitted loop.
to the factor total fabric areafabric. corresponding to one loop. It is analogous to the cover of woven Figure 1.21 depicts the repeat unit of a single jersey knitted fabric. e total area of the t he repeat (in square inch) is equal to tthe he product product of 1/cpi 1/cpi and and wpi.. e area covered by the yarn can be calculated by the product of 1/ 1/wpi loop lengt length h (l (l inch) and yarn diameter (d (d inch) inch),, assuming assumi ng that the loop has a planner structure. erefore, Tightness factor =
=
Area covered by the yarn within the repeat unit Area of the repeat unit l ´ d l ´ d = 1 1 l l ´ ´ cpi wpi k c k w
=
k c ´ k kw ´ d ks ´ d = l l
Yarn d diameter iameter (d (d ) is proportionate proportionate with wit h (tex) (tex)0.5. erefore,
Tightness factor µ
k s ´ tex l
(1.13)
When the knitted structure is same and the relaxation state of the fabric tex/l l can is also same, then t hen tex/ can be used for comparison of tightness factor (Ray, 2012 2 012). ).
Introduction to Fabric Manuacturing
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25
1.4 NONWOVEN TECHN TECHNOLOGY OLOGY A nonwoven nonwoven is a sheet of fibres, continuous filaments fila ments or chopped yarns of any nature or origin that have been formed into a web by any means and bonded together by any means, with the exception of weaving or knitting. Felts obtained by wet milling are not nonwovens (www.edana.org (www.edana.org). ). Nonwovens are engineered and flat structured sheets which are made by bonding and entangling of fibres by means of mechanical, thermal or chemical processes. Nonwoven technology has attracted the attention of researchers and industrialists as it can manufacture the fabric at a very high production rate bypassing the yarn production stage. e principal end-uses of nonwoven materials are found in technical textiles such as geotextiles,, filtration, wipes, health geotextiles healt h and hygiene prod products, ucts, surgical surg ical gowns, face masks, masks , automotive automotive textiles texti les and so on. e two major stages of nonwononwo ven manufacturing manufactu ring aare re web formation and web bonding. e major nonwoven technologies technologies can be listed as follows: Web Formation
Mech echanically lly ffo orme rmed fib fibre we webs (Dryla rylaiid) Aerod Ae rodyna ynamic micall allyy fo forme rmed d fib fibre re webs webs (Drylai (Drylaid) d) Hydrody Hy drodynam namically ically formed formed fibre fibre webs webs (Wetlai (Wetlaid) d) Polymer-laid (Spunmelt nonwovens)
Web Bonding
Needl edle pu punching Hydro-e ydro-ent ntan anglem glemen entt ermal ermal b bondi onding ng Chemical bonding
Drylaid, wetlaid and polymer-laid web formation formation systems have their roots in textile, paper making and polymer extrusion processes, respectively.
1.4.1 .4.1 Needle Nee dle Punching Technology echnology
Needle punching is the most common web bonding method. It is the method of consolidation of fibrous webs by repeated insertion of barbed needles into the web as shown in Figure 1.22. e needling can be done either from one side or from both (top and bottom) sides of the web. is process consolidates the structure of fibrous web by interlocking of fibres in the third or ‘Z’ dimension without using any binder. Continuous filaments or short staple fibres are initially arranged in the form of a fibrous web in various orientations (random, cross, parallel para llel or composite). composite). e degree of compaction of the fibrous web is largely dependent on punch density (P (PD), which is defined as the number of needle penetrations received by the fibrous web per unit area (punches/cm2). If the stroke frequency (cycles/min) of the needle board is N and and the number of needles per
26
Principles o Woven Fabric Manuacturing
◾
Stripper plate
Delivery rollers Needle board 1
Web
Bed plate Needle punched fabric
Feeder conveyor
Needle board 2
FIGURE 1.22 Needle punching process.
linear cm width of the t he needle board board is n and the delivery speed of the fabric is v cm/min, cm/min, then punch density can be calculated by the following expression.
N ´ n Punch density PD = cm 2 v -
(1.14)
erefore, increase in stroke frequency or the number of needles per cm width of the needle board will wi ll increase the t he punch density density for a given delivery speed. Higher punch density creates more fibre entanglement in the web, thus increasing the compactness of the web. Needle-punched Needle-pun ched nonwove nonwoven n geotextiles geotexti les are extensively ex tensively used in civ civil il engineering applications, applications, including road and railway construction, landfil landfills, ls, land reclamation and slope stabilisation. Such applications require geotextiles to perform more than one function, including filtration, drainage and separation. e properties of needle-punched nonwoven fabric depend on parameters such as fibre type, ty pe, web aerial density, needle penetration penetration depth, punch density (number of punches/cm2) and the number of needling passages.
1.4.2 Hydro-Entanglement Technology Hydro-entanglement, or spunlacing, is a versatile method of bonding the fibrous web using high-pressure water jets. In this process, a fabric is produced by subjecting a web of loose fibres to high-pressure fine water jets as shown in Figure 1.23. e fibre web is supported by either regularly spaced woven wires or a surface with randomly distributed
Introduction to Fabric Manuacturing
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27
Injectors Jets Nozzles Hydro-entangled web
Web
Suction
Suction Suction
Suction Cylinder
Porous support sheet
FIGURE 1.23 Hydro-entanglement process. (From Banerjee, P.K., Principles o
Fabric Formation, Formation, CRC Press, Boca Raton, FL, 2015.)
holes (Perfojet technology). As a result of the impact of high-pressure jets,, the fibres bend and curl around each other, forming jets formi ng an integ integrated rated web where fibres are held together by frictional forces. e fabrics are finally final ly dried to remove the water. water. e resulting fabric strength depends on the web properties (areal density, thickness, etc.), fibre parameters (fibre diameter, cross-section, bending modulus, etc.) and forming wires geometry and jet parameters. Hydro-entangled nonwovens have an extensive range of applications, including wipes, carpet backing, filters, sanitary, medical dressings and composites. Among these applications, personal care and household wipes form the fastest growing sector. Use of natural resources like water and energy (for drying) is a concern with this technology.
1.4.3 Spunbond Technology Spunbond and meltblown fabrics belong to the class of polymer-laid nonwovens. In spunbonding process, fluid polymer is converted into finished fabric by a series of continuous operations as shown in Figure 1.24. Polymer melt is first extruded into filaments and then the filaments are attenuated. While the filaments are being attenuated, they remain under tension. Aer attenuation, the tension is released and the filaments are forwarded to a surface where the web is formed. e web is then subjected to the bonding process which can be done by chemical and/or thermal process. A binder may be incorporated in the spinning spin ning process or applied subsequently subsequently..
28
Principles o Woven Fabric Manuacturing
◾
Polymer chips feed
Molten polymer
Extrusion die
Extruder
Filament attenuator cooling and stretching
Fibre laying
Winding
Laydown
Calender bonding
FIGURE 1.24 Spunbonding process.
Polypropylenee and Polypropylen a nd polyester are commonly used for spun-bonding process. Spun-bonded nonwovens have high strength but lower flexibility.
1.4.4 Meltblown Technology
Meltblown technology is unique in the sense that the web is very fine along with very small pore sizes which no other nonwoven technology can match. e polymer is fed into the die tip and the resulting fibre is attenuated by hot air, which is blown near the die tip as shown in Figure 1.25. Air and fibre are expanded into the free air. Due to the mixture mi xture of high-speed air and fibre with ambient air, the fibre bundle starts its movement forward and backward creating ‘form drag’. is form drag appears with every change of fibre direction. erefore the meltblown fibres usually do not have a constant diameter. e fibres in the meltblown web are laid together by a combination of entanglement and cohesive sticking. e ability to form a web directly from a molten polymer without controlled stretching gives meltblown technology a distinct cost advantage over other systems.
Introduction to Fabric Manuacturing
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29
Die tip Air knife
Polymer
Air knife
Hot air
Conveyor belt
FIGURE 1.25 Schematic diagram of meltblown process.
Meltblown webs offer a wide range of characteristics such as random fibre orientation, very fine fibre and low to moderate web strength. e major end-uses of monolithic meltblown fabrics are filtration media (surgical mask filters, liquid and gas filtration), surgical disposable gown, sterilisation warp, disposable absorbent products and oil absorbents. About 40% of meltblown fabrics are used in uncombined (monolithic) state. e laminated SMS (spunbond-meltblown-spunbond) structures are ideal for gradient filtration as the material shows excellent barrier properties combined with mechanical strength. e filtration efficiency is oen increased by applying electrostatic charges to the filaments. With thiss standa thi standard rd meltblown meltblown technology, technology, fibres of 1–3 1–3 µm diameter d iameter can be produced. Several filter applications using meltblown nonw nonwovens ovens are already in the t he market today. today.
1.5 BRAIDING TECHNOLOGY Braiding generally produces tubular or narrow fabrics by intertwining three or more strands of yarns, threads or filaments. e yarn packages move on serpentine path as shown in Figure 1.26. In simple machines, half of the packages move in clockwise direction, whereas the remaining packages move in anticlockwise direction. di rection. Shoelaces and ro ropes pes are manufactured using braiding systems. Profiled braided structures are also used as composite performs. e interlacement pattern of braided structures has resemblance with that of woven structures. For example, Diamond, Regular and Hercules braids have interlacement patterns similar to those of plain, 2 × 2 and 3 × 3 twill weaves, respectively.
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Principles o Woven Fabric Manuacturing
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FIGURE 1.26 Paths of yarn packages in braiding machine.
During the braiding process, the yarns form helical paths around a mandrel. e braid braid angle is defined as the angle between the yarn ax axis is and the braid axis. is is similar to the twist angle of a fibre inside the yarn. e braid angle is a very important parameter for the braided structure and can be calculated using the following expression.
æ w r ö ÷ è TUS ø
Braid angle = q = tan -1 ç
(1.15)
where ω is the t he average angular velocity of the package (rad/s) (rad/s) r is the t he mandrel radius (cm) US is the take-up speed (cm/s) If the t he number of of yarn careers c areers or yarn packages is K , then the braided structure forms K /2 /2 number of parallelograms in the circumferential direction. is is i s shown in Figure 1.27. 1.27.
Introduction to Fabric Manuacturing
◾
31
n l i o a t i x c e A r i d
C
Circumferencial direction A
B
D
FIGURE 1.27 Unit cell of braided structure.
e cover cover factor for the above above braided structure struct ure can be calculated ca lculated using the following expression (Potluri (Potluri et al., 2003 20 03). ). 2
W æ y K ö Cover factor = 1 - ç 1 ÷ è 4 pr cos q ø
(1.16)
where W y is the yarn width r is is the mandrel radius θ is the braid angle
NUMERICAL PROBLEMS 1.1 e llength ength of a fabric is 10 10 m. e length length of a warp yarn, removed removed from the fabric, in straight str aight condition is 10.8 10.8 m. Determine the cr crimp imp % and contraction % in warp direction.
Solution: Crim Cr imp p%=
L yarn - L fabric L fabric
´
100
where L yarn yarn is the length of warp yarn removed from the fabric L abr abric ic is the length of fabric
32
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Principles o Woven Fabric Manuacturing
So Crimp =
(1.08 - 1) ´ 100 = 8% 1
Contraction =
L yarn - L fabric
´
100
L yarn =
1.08 - 1 41 1% ´ 100 = 7.4 1.08
So, the cri crimp mp and contraction contrac tion are 8% and 7.41 .41%, %, respec respectively. tively.
1.2 Prove that for for cotton yarn with packing factor of 0.6, diameter 1 (inch) 28 Ne =
Solution:
Figure 1.28 shows a cylindrical cylindrica yarn. e count the yarn is inch Ne. e diameter and length of the lyarn (for mass of 1ofpound) is d inch and l inch, inch, respectively. As the yarn count is ‘Ne’, ‘Ne’, there wi will ll be Ne number of hank hankss (840 yards) in 1 pound. us length (l ) = Ne Ne × 840 × 36 inch. Densit Densityy of cotton fibre is 1.51 g/cm3. As the packing factor is 0.6, the density of the cotton yarn wi will ll be 1.51 × 0.6 = 0.906 g/cm 3.
So 0.90 906 ´ 2.54 5 43 The density of cotton yarn = pound/inch3 453.6 =
0.03 327 27 pound/inch3
d
l
FIGURE 1.28 Yarn with w ith circular cross section.
Introduction to Fabric Manuacturing
The volume of yarn =
Mass of the yarn =
◾
33
d 2 l inch 3 4
p
d 2 l ´ 0.0325 pound 4
p
d 2 ´ Ne ´ 840 ´ 36 ´ 0.03 = 0 327 p pound ound 4 p
=1 pound (by definition)
erefore, d (inch) d (inch)
=
1 28 Ne
1.3 A co cotton tton fabric fabric is made from 20 Ne warp and ends ends per inch is 50. Determine the warp cover factor.
Solution: Two consecutive ends are shown in Figure 1.29. 1.29. Here, ends per inch = 50 End spacing ( p ) =
1 = 0.02 inch 50¢¢
Warp ar p count = 20 Ne So Warp yarn diameter (d )
=
1 28 Ne
=
1
inch
=
28 20
d/2
p
FIGURE 1.29 Spacing between two ends.
d/2
0.008 inch
34
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Principles o Woven Fabric Manuacturing
Now, Warp cover factor = 28 ´
=
28 ´
0.008
=
11.2
0.02
d p
So warp cover factor is 11.2.
K K 1.4 Show that the expression for fabric cover factor is K 1 + K 2 - 1 2 , 28 where K 1 is warp cover factor and K 2 is we cover factor.
Solution: Figure 1.30 shows the repeat unit of a plain woven fabric. Let d 1 is the diameter of warp yarn, d 2 is the diameter of we yarn,
p1 is the end spacing, p2 is the pick spacing. Fractional cover =
Area covered by the yarns within the repe aatt Area of the repeat
=
d1 p2 + d2 p1 - d1d 2 p1 p 2
=
d 1 d 2 + p 1 p 2
-
d1d 2 p1 p 2
d 2
p2
d 1
p1
FIGURE 1.30 Repeat unit of a plain woven fabric.
Introduction to Fabric Manuacturing
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35
Cover ffaactor = 28 ´ Fractional co cover =
28
d 1 p 1
+
28
d 2 p 2
-
28
d1d 2 p1 p 2
So K K Fabric cover factor ( K f ) = K 1 + K 2 - 1 2 28
1.5 Calcu Calculate late the areal density (g/m2) of the cotton fabric having the t he following specifications: Warp and we count: 22s × 18s; 25 ends per cm × 16 picks per cm; warp crimp is 6.5% and we crimp is 8.5%.
Solution: Warp count is 22 Ne
=
590.5
Weft count is 18 Ne
=
26.8 84 4 tte ex (T 1 )
=
590.5 18
=
32.8 81 1 t ex (T 2 )
Ends per cm (N 1) = 25 Picks per cm (N 2) = 16 Warp crimp (C 1) = 6.5% We crimp cri mp (C 2) = 8.5% Areal density of fabric =
=
22
tex
1 é
æ C 1 ö æ C 2 ö ù 1 N T N T + + 1 1 2 2 ç ÷ ç1 + ÷ú ê 10 ë è 100 ø è 100 ø û 1 é æ 6.5 ö æ 8.5 ö ù 2 5 2 6 . 8 84 4 1 1 6 3 2 . 8 81 1 ´ + + ´ ÷ú ç ÷ ç1 + 10 êë 100 è ø è 100 ø û
g/m m2 = 128.42 g/
So, the areal density of the fabric is 128.42 g/m2.
1.6 Calculate the porosity and thermal conductivity of a needle-punched nonwoven fabric made of 100% polypropylene fibres (density is 0.9 g/cm3) having the thickness t hickness of 3 mm. e areal density of the nonwoven fabric is 300 g/m2 and the thermal conductivity of polypropylene fibre is 0.12 W/m W/m K.
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Principles o Woven Fabric Manuacturing
◾
Solution: Let fabric areal density or GSM is G g/m2, thickness of fabric is m m and density of fibre is ρ is ρ g/m g/m3.
æ
G ö ÷ ´100 è T ´ r ø
Then porosity ( % ) = ç 1 -
where = 3 mm = 0.003 m ρ = 0.9 g/cm3 = 0.9 × 10 6 g/m3
So
æ è
Porosity = = ç 1 -
300 ö ´100 6 ÷ 0.00 003 ´ 0.9 ´10 ø
= (1 - 0.111) ´100 = 88.89%
æ è
Thermal conductivity of fabric = ç 1 -
P P ö K + ´ K air r fibre ÷ 100 ø 100
88.89 æ 8 8.89 ö = ç1 0 12 + ´ 0.025 . ÷ 100 è 100 ø
= 0.036 W/m K
So the porosity and thermal therma l conductiv conductivity ity are 88.89% and 0.036 W/m K, respectively.
REFERENCES Banerjee, P. K. 2015. Principles o Fabric Formation. Formation. Boca Raton, FL: FL: CRC Press. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion o Yarn to Fabric, Fabric , 2nd edn. Merrow, UK: Merrow Technical Library. Libra ry. Marks, R. and Robinson, A. T. C. 1976. Principles o Weaving . Manchester, UK: e Textile Institute. Potluri, P., Rawal, A., Rivaldi, M. and Porat, I. 2003. Geometrical modelling and control of a triaxial braiding machine for producing 3D performs. Composites: Part A, A, 34: 481–492. Ray, S. 2012. Fundamentals and Advances in Knitting echnology . New Delhi, India: Woodhead Woodhead Publishing India Pvt. Ltd.
References 1 CHAPTER 1 Introduction to Fabric Manufacturing Banerjee, P. K. 2015. Principles of Fabric Formation. Boca Raton, FL: CRC Press. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Marks, R. and Robinson, A. T. C. 1976. Principles of Weaving. Manchester, UK: �e Textile Institute. Potluri, P., Rawal, A., Rivaldi, M. and Porat, I. 2003. Geometrical modelling and control of a triaxial braiding machine for producing 3D performs. Composites: Part A, 34: 481–492. Ray, S. 2012. Fundamentals and Advances in Knitting Technology. New Delhi, India: Woodhead Publishing India Pvt. Ltd.
2 CHAPTER 2 Winding Aggarwal, A. K., Hari, P. K. and Subramanian, T. A. 1987. Evaluation of classimat faults for their performance in weaving. Textile Research Journal, 57: 735−740. Banerjee, P. K. and Alagirusamy, R. 1999. Yarn Winding. New Delhi, India: NCUTE Publications, Indian Institute of Technology. Booth, J. E. 1977. Textile Mathematics, Vol. III. Manchester, UK: �e Textile Institute. Koranne, M. 2013. Fundamentals of Yarn Winding. New Delhi, India: Woodhead Publishing Limited. Kretzschmar, S. D. and Furter, R. 2008. Application report of Uster classimat quantum, Uster Technologies AG, Uster, Switzerland. http://www.uster. com. Accessed on 21st March 2016. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Rust, J. P. and Peykamian, S. 1992. Yarn hairiness and the process of winding. Textile Research Journal, 62: 685−689. Technical literature of Autoconer X5, Saurer-Schla�orst, Germany. www.saurer. com. Accessed on 21st March 2016.
3 CHAPTER 3 Warping Banerjee, P. K. 2015. Principles of Fabric Formation. Boca
Raton, FL: CRC Press. Booth, J. E. 1977. Textile Mathematics, Vol. III. Manchester, UK: �e Textile Institute. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Technical literature of warping machine Ben-direct, 2003, Benninger Co. Ltd., Uzwil, Switzerland.
4 CHAPTER 4 Warp Sizing Banerjee, P. K. 2015. Principles of Fabric Formation. Boca Raton, FL: CRC Press. Goswami, B. C., Anandjiwala, R. and Hall, D. M. 2004. Textile Sizing. New York: Marcel Dekker, Inc.
Hari, P. K., Behera, B. K., Prakash, J. and Dhawan, K. 1989. High pressure squeezing in sizing: Performance of cotton yarn. Textile Research Journal, 59: 597−600. Maatoug, S., Ladhari, N. and Sakli, F. 2007. Evaluation of weaveability of sized cotton warps. AUTEX Research Journal, 8: 239−244. Ormerod, A. and Sondhelm, W. S. 1995. Weaving: Technology and Operations. Manchester, UK: �e Textiles Institute. Technical literature of Selvol™ Polyvinyl Alcohol for Textile Warp Sizing, 2011, Sekisui Specialty Chemicals, Osaka, Japan, www.sekisui-sc.com. Accessed on 21st March, 2016. Technical literature of TTS20S spun sizing machine, T-Tech Japan Corp., Ishikawa, Japan, www.t-techjapan.co.jp. Accessed on 21st March, 2016.
5 CHAPTER 5 Weave Design Grosicki, Z. J. 1997. Watson’s Textile Design and Colour. Cambridge, UK: Woodhead Publishing Limited. Robinson, A. T. C. and Marks, R. 1967. Woven Cloth Construction. Manchester, UK: �e Textile Institute.
6 CHAPTER 6 Shedding Banerjee, P. K. 2015. Principles of Fabric Formation. Boca Raton, FL: CRC Press. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Marks, R. and Robinson, A. T. C. 1976. Principles of Weaving. Manchester, UK: �e Textile Institute.
7 CHAPTER 7 Picking in Shuttle Loom Banerjee, P. K. 2015. Principles of Fabric Formation. Boca Raton, FL: CRC Press. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Marks, R. and Robinson, A. T. C. 1976. Principles of Weaving. Manchester, UK: �e Textile Institute.
8 CHAPTER 8 Picking in Shuttleless Loom Adanur, S. 2001. Handbook of Weaving. Lancaster, UK: Technomic Publishing Company, Inc. Adanur, S. and Turel, T. 2004. E�ects of air and yarn characteristics in air-jet �lling insertion: Part II: Yarn velocity measurements with a pro�led reed. Textile Research Journal, 74: 657−661. Banerjee, P. K. 2015. Principles of Fabric Formation. Boca Raton, FL: CRC Press. Luenenschloss, J. and Wahhoud, A. 1984. Investigation into the behaviour of yarns in picking with air-jet systems. Melliand Textilberichte, 65: 242. Marks, R. and Robinson, A. T. C. 1976. Principles of Weaving. Manchester, UK: �e Textile Institute. Shyam, A. F., Workshop on Opportunities for Industrial Fabrics Producers, 6th November, 2014, Indian Institute of Technology, Delhi. Technical literature of Toyota water-jet loom LWT 710, 2015, Toyota Industries Corporation, Japan.
Vangheluwe, L. 1999. Air-Jet Weft Insertion (Textile Progress). Manchester, UK: �e Textile Institute. Wahhoud, L., Weide, T. and Jansen, W. 2004. Air index tester: Manufacturing behavior of rotor yarns on air-jet weaving machines. Melliand International, 10: 277−279.
9 CHAPTER 9 Beat-Up Booth, J. E. 1977. Textile Mathematics, Vol. III. Manchester, UK: �e Textile Institute. Bullerwell, A. C. and Mohamed, M. H. 1991. Measuring beat-up force on a water jet loom. Textile Research Journal, 61: 214−222. Greenwood, K. 1975. Weaving-Control of Fabric Structure. Merrow, UK: Merrow Technical Library. Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Marks, R. and Robinson, A. T. C. 1976. Principles of Weaving. Manchester, UK: �e Textile Institute. Shih, Y., Mohamed, M. H., Bullerwell, A. C. and Dao, D. 1995. Analysis of beatup force during weaving. Textile Research Journal, 65: 747−754.
10 CHAPTER 10 Secondary and Auxiliary Motions Lord, P. R. and Mohamed, M. H. 1982. Weaving: Conversion of Yarn to Fabric, 2nd edn. Merrow, UK: Merrow Technical Library. Marks, R. and Robinson, A. T. C. 1976. Principles of Weaving. Manchester, UK: �e Textile Institute.
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