TEXTILE SIZING BHUVENESH C. GOSWAMI Clemson University Clemson, South Carolina, U.S.A. RAJESH D. ANANDJIWALA CSlR University of Port Elizabeth Port Elizabeth, South Africa DAVID M. HALL Auburn University Auburn, Alabama, U.S.A. MARCEL DEKKER, INC. DEKKER NEW YORK * BASEL Copyright © 2004 Marcel Dekker, Inc. Although great care has been taken to provide accurate and current information, neither the author(s) nor the publisher, 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. The material contained herein is not intended to provide specific advice or recommendations for any specific situation. Trademark notice: Product or corporate names may be trademarks or registered trade- marks and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress. ISBN: 0-8247-5053-5 This book is printed on acid-free paper. Headquarters Marcel Dekker, Inc., 270 Madison Avenue, New York, NY 10016, U.S.A. tel: 212-696-9000; fax: 212-685-4540 Distribution and Customer Service Marcel Dekker, Inc., Cimarron Road, Monticello, New York 12701, U.S.A. tel: 800-228-1160; fax: 845-796-1772 Eastern Hemisphere Distribution Marcel Dekker AG, Hutgasse 4, Postfach 812, CH-4001 Basel, Switzerland tel: 41-61-260-6300; fax: 41-61-260-6333 World Wide Web http://www.dekker.com The publisher offers discounts on this book when ordered in bulk quantities. For more information, write to Special Sales/Professional Marketing at the headquarters address above. Copyright 2004 by Marcel Dekker, Inc. All Rights Reserved. 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 re- cording, or by any information storage and retrieval system, without permission in writing from the publisher. Current printing (last digit): 10987654321 PRINTED IN THE UNITED STATES OF AMERICA Copyright © 2004 Marcel Dekker, Inc. PREFACE Textile processes have experienced radical change due to new inventions and the stringent demands of high-quality products. The past three decades have seen the development of new fibers, new spinning methods and new weaving techniques as well as the value addition of existing products and increased productivity of current processes. Modern looms are operating at very high speeds, thus imposing stringent requirements on the warp that can be woven efficiently. In the sequence of textile processes, sizing has continued to retain its importance in the value chain and has proved necessary even with today’s demanding requirements. Using innovative techniques, the sizing machine and chemical manufacturers have tried to keep pace with the increased speed of looms. Despite the rapidly changing scenario in textile processing and atten- dant research in sizing, little of this progress has been documented in a single volume. The motivation to write this book arose from this gap, and the material developed from continued research at Clemson University provided the foun- dation. The subject of sizing is complicated because of the important roles played by interactions among fiber type, yarn type, sizing chemicals, prepara- tory weaving processes, characterization of the performance of sized yarns that can help in predicting the behavior of warp during weaving, easy size removability after weaving, and environmental pollution. Prediction of the efficiency of sizing—type of size, amount of size, penetration of size in differ- ent yarn structures, and the mode of different deformations of the sized yarns—in terms of weaving efficiency has confounded textile scientists and Copyright © 2004 Marcel Dekker, Inc. PREFACEiv technologists for a long time. The subject matter in this volume is arranged with this in mind. The introductory chapter summarizes the importance of fiber properties, yarn quality, sizing process, sizing materials and their evaluation, performance evaluation of sized yarn and the sizing process, and modern in- strumentation and control of the sizing machines. Chapter 2 is devoted to different fibers and yarns and their properties. Most recently developed fibers are covered, and then principles of different spinning systems are described to enable the reader to understand the structural differences in various yarns. Recently developed yarn spinning systems are described to acquaint the reader with modern developments and their effects on sizing. Chapter 3 is devoted to the chemistry of sizing ingredients and their properties that determine suita- bility for applications. The importance of desizing and its effect on size recov- ery and environment pollution are also discussed. Good preparatory processes, such as winding and warping, and their effect on the sizing operation are discussed in Chapter 4. Besides the basic principles of winding, warping and sizing operations, this chapter also covers the principles of process controls and modern instrumentation techniques. Ef- fect of sizing machine parameters and practical aspects are briefly described. Single-end sizing systems for filament sizing have become popular in the past two decades, along with developments in draw-warping and sizing to improve the economics of processes. Chapter 4 also deals with the principles of sizing of different types of yarns such as ring, rotor, and filament. The efficiency of sizes on yarns in terms of the types of loom used for weaving is also examined. Prewetting of spun yarns, with its impact on the economy of sizing, is pre- sented. Chapter 5 deals with performance evaluation of sized yarns. The major portion of this chapter is drawn from the research material developed through exhaustive studies conducted at Clemson University over the past fifteen years. A comprehensive bibliography on sizing is appended for the benefit of re- searchers and interested readers who would like to delve into the subject matter in more detail. References in the bibliography include material that is scattered in various publications in several languages besides English. This text has been developed with a view to providing systematic infor- mation for textile students, engaged in both undergraduate and research studies. The information presented will help textile practitioners comprehend the pre- vailing practices in the industry and understand the changing processes and practices. Bhuvenesh C. Goswami Rajesh D. Anandjiwala David M. Hall Copyright © 2004 Marcel Dekker, Inc. CONTENTS Preface 1. The Sizing Process 1.1 Introduction 1.2 Material Properties 1.3 Sizing Materials 1.4 Performance Evaluation 1.5 Selection and Evaluation of Size Materials 1.6 Evaluation of the Sizing Process 1.7 Evaluation of Warp Performance 1.8 Closing Notes References 2. Properties of Fibers and Yarns 2.1 Introduction 2.2 Fibers 2.3 Staple Yarn Spinning Systems 2.4 Yarn Structure 2.5 Properties of Staple Yarns References Copyright © 2004 Marcel Dekker, Inc. CONTENTSvi 3. The Chemistry of Sizing Compounds 3.1 Introduction 3.2 Properties of Size Materials 3.3 Starch 3.4 Polyvinyl Alcohol 3.5 Carboxyl Methyl Cellulose 3.6 Acrylics 3.7 Binders 3.8 Styrene/Maleic Anhydride Sizes 3.9 Size Recovery and Desize Wastewater Treatment References 4. Winding, Warping, and Sizing 4.1 Introduction 4.2 Winding 4.3 Warping 4.4 Sizing 4.5 Single-End Sizing Systems 4.6 Draw-Warping and Sizing 4.7 Sizing of Different Yarns 4.8 Prewetting of Spun Yarns References 5. Performance of Sized Yarns 5.1 Introduction 5.2 Criteria of Assessment References Bibliography on Sizing Copyright © 2004 Marcel Dekker, Inc. 1 THE SIZING PROCESS 1.1 INTRODUCTION The old adage that sizing is the heart of weaving still holds good today. This statement is all the more important in today’s environment when loom speeds have increased tenfold from those used in shuttle looms. The weaving process depends upon a complexity of factors which include the material characteris- tics, the sizing ingredients, the sizing operation, and the yarn parameters. Table 1.1 shows all the important factors that come into play in deciding the perfor- mance of warp yarns during weaving. On the whole, the aim of the textile technologist is to produce ‘‘quality’’ fabric economically and efficiently. Here these terms refer to the production of fabrics up to the loom stage. The selection, evaluation, and performance of the warp (yarn/size sys- tem) for any specific fabric sett and the loom must be determined in the context of the developments and changes that have occurred in the spinning/winding/ warping and the slashing processes. The following is a brief discussion of a number of considerations that a textile technologist must be conversant with when making a decision regarding the appropriate yarn/sizing system. In the past four decades, the weaving industry has been subject to inordi- nate competition which has primarily come from the fashion (short runs), knitting, and nonwoven segments. The weaving machinery manufacturers an- swered the pressure of competition by concentrating on the design of looms that offered relatively very high speeds. Table 1.2 shows the relative speeds of various processes of manufacturing fabrics. Obviously, to meet the demands Copyright © 2004 Marcel Dekker, Inc. Chapter 12 Table 1.1 Parameters Affecting Performance of Warp Yarns During Weaving Material characteristics Fiber type, e.g., cotton, polyester, acetate Yarn type and structure including blend composition, e.g. staple Ring, open end, air-jet, combed, carded, core spun, continuous filament Yarn hairiness. Yarn preparation Winding Warping Slashing Tension on yarn during sizing Moisture content Drying temperature Slashing machine parameters Slashing speed Size box characteristics High pressure squeeze rolls, including hardness of rolls Type of sizing method, e.g., single end, Cutt method, foam method Amount of size Yarn tension Closeness of yarns Loom parameters Type of loom, e.g., shuttle, rapier, projectile, air-jet Weave Loom speed Warp tension of the higher productivity on the loom, the material characteristics and the quality and efficiency of the preceding processes also needed to be improved. This volume deals with the material characteristics, yarn structure and proper- ties, yarn preparation, chemistry of sizing ingredients, and the performance analysis of sized yarns subjected to simulated loom parameters and its correla- tion with actual performance on the loom. The attempt to put this material in the present form comes at a time when the emphasis in the weaving industry is shifting away from simply higher production speeds toward optimization of the weaving process, dependability, and fabric quality. The difficulty in predicting the performance of warp during actual weav- ing is compounded by the fact that there have been a number of developments in materials and preparation and processing techniques that have taken place Copyright © 2004 Marcel Dekker, Inc. The Sizing Process 3 Table 1.2 Relative Production Rates for Textile Processes Fabric/fiber sheet Relative making process Machine production rate a Average output 5 m 2 /h, 150 picks/min. Weaving Knitting and hosiery Nonwoven bonded fabrics Dry method Wet method Paper manufacture Automatic loom with shuttle a Shuttleless looms Rapier Projectile Air-jet Multiphase Circular knitting machine (wide) Warp knitting loom Stitch bonding machine Short fiber carding, nonwoven card Long fiber carding, garnetting Tufting machine Aerodynamic web-making machine spun-bonding machine Rotoformer Paper-making machine (high powered type) 1 2 3 10 30 4 16 38 120 400 500 600 200–2,000 2,300 40,000–100,000 over the past three decades. The following is the discussion of some of the factors that needed to be considered when evaluating and predicting the perfor- mance of warp during weaving. With almost a constant demand for improving the quality and productivity in weaving there has been an equal emphasis on the development of better quality yarns with improved tenacity, elongation, elastic recovery, in both the dry and wet state, and above all in reduction in hairiness of staple yarns. 1.2 MATERIAL PROPERTIES There have been a number of developments in the quality of cotton fibers produced around the world. Although there has been a constant and gradual improvement in strength and elongation of the upland variety, one noticeable development that is worth mentioning here is the significant improvement that has occurred in the area of the strength and elongation of extra long cotton Copyright © 2004 Marcel Dekker, Inc. Chapter 14 fibers. The strength of most of these extra long staple cottons is in the range of 35–37 cN/tex, and elongation varies anywhere from 6 to 8%. These properties translate very well into improvement in yarn characteristics. In practical mill operation, the strength property of the yarn has always been considered the prime factor that influences the performance of warp yarn during weaving. However, in recent years the mill supervisors and textile scien- tists have realized that other mechanical characteristics—such as elongation, elastic recovery in both wet and dry states, and physical characteristics such as abrasion resistance and moisture sorption—are equally influential in perfor- mance in the loom shed. On the other hand, as far as synthetic fibers are con- cerned, the trend has been more toward using finer fibers, especially when con- sidering polyester fibers for blends with cotton. Polyester fibers of denier as low as 0.7 have been developed, but most commonly used fibers are in the range of 1 to 1.2 denier in current mill practice. This increases the number of fibers in the yarn crosssection, which eventually enhances the strength, elastic recovery, and abrasion resistance of the resultant yarns. There has not been much change in the strength and elongation properties of synthetic fibers. However, it is not the new material (fiber) properties alone that account for the continuous improvement in yarn quality; optimization of the processes, despite the increase in speed, has made the process of sizing and weaving much more efficient. This is true for most spun and filament yarns. The im- provement in the quality of yarn over the last three decades can be best demon- strated by the data published by Zellweger Uster [1] for staple yarns. It is fairly safe to assume that there has not been much change in fiber length distribution, fineness, strength distribution and trash content in the raw stock of natural fibers; the properties of the yarns then are a function of the vagaries of the spinning processing technologies. The variations in a yarn that have an important influence on the efficiency of the weaving process are yarn mass variations, thin places, and strength variation. Numerous studies have demon- strated some correlation between thread breaks and thin places and variation in yarn strength. Figures 1.1 and 1.2 show the reduction in the coefficient of variation of strength and thin places of the 50% line of the Uster statistics of ring-spun combed 10 tex yarn, respectively. Even such a small reduction in the variation in yarn strength can significantly influence the yarn failure rate on the loom. There have been significant improvements in the quality of both ring- and open-end rotor-spun yarns. Online monitoring of yarn quality during spinning and splicing during winding, clearing devices, and yarn tension control on modern machines have improved the final yarn quality that is delivered to the warping department. Fiber and yarn characteristics are discussed in detail in subsequent chap- ters. Copyright © 2004 Marcel Dekker, Inc. [...]... size material will behave during sizing, weaving, and desizing or in recycling of the materials Carboxymethyl cellulose (CMC) sizing has very good adhesion to cellulosic fibers, but due to the high viscosity, the concentrations used in the industry are limited to low levels CMC sizes are combined with PVA or acrylic sizing agents to improve their performance and desizing characteristics However, the...The Sizing Process Fig 1.1 Strength variation; percent CVFmax Fig 1.2 Variation of thin places (imperfections) Copyright © 2004 Marcel Dekker, Inc 5 6 Chapter 1 1.3 SIZING MATERIALS Natural starch and its derivatives still constitute nearly 75% of the sizing agents used in the textile industry throughout the world It will remain the predominant... Laboratories, Inc: Greensboro: North Carolina 3 Textile Yarns: Technology, Structure & Applications Goswami B C., Martindale J G., Scardino F L., Eds.; John Wiley and Sons: New York, 1977 4 Seydel, P V.; Hunt, J R Textile Warp Sizing; Seydel Wooley & Co Phoenix Printing: Atlanta, Georgia, USA, 1981 5 Ormerod, A.; Sondhelm, W S Weaving: Technology and Operations; The Textile Institute: Manchester, UK, 1995... keep pace with changing weaving technologies, the process of sizing and ingredients used for sizing have also changed The success of the sizing operation, on which the success of weaving and to some extent the quality of woven fabric are based, is influenced by the quality and properties of the warp yarns Before discussing the process of sizing it is important to know the properties of fibers used... Dekker, Inc 2 PROPERTIES OF FIBERS AND YARNS 2.1 INTRODUCTION The utilization and serviceability of textile materials, other than industrial or technical textiles, are determined by their physical and mechanical properties, which include softness, pliability, good handle, feel, and drape [1] The pliability of a textile structure is attributed to the fact that it is composed of a number of individual elements,... parameters Nevertheless, we hope this compendium will prove to be of great help to both mill practitioners and the students of textiles and especially weaving This volume is primarily concerned with familiarizing the reader with the current status of sizing machines, chemistry of different sizing materials, and above all the laboratory methods of evaluation of sized yarns In addition, the correlation between... and similar to some naturally available cellulosic and protein fibers 2.2.1 Classification of Textile Fibers Textile fibers are broadly classified into two major groups: (1) natural and (2) manmade, depending upon the nature of their origin Natural fibers still account for a major share (some 45%) of the total textile fiber consumption around the world The term ‘‘manmade’’ applies to all fibers that include... Properties of Textile Fibers The choice of textile fibers to be used as raw materials in a specific application depends upon a unique combination of different properties The most essential and desirable properties may be broadly categorized as Copyright © 2004 Marcel Dekker, Inc 24 Chapter 2 Dimensional or geometric Physical Mechanical General Table 2.3 lists various essential properties of textile fibers... density of textile materials plays an important role in processing behavior and the ultimate fabric properties Crimp is another important property of Copyright © 2004 Marcel Dekker, Inc Properties of Fibers and Yarns 29 textile fibers, especially those of natural origin, but is not that common in the case of other solid materials The manmade fibers are usually crimped before processing on the textile. .. finished fabric requirements as fabric hand, brightness of color, and texture 1.6 EVALUATION OF THE SIZING PROCESS Weavers have been placing very stringent requirements on the quality of warp due to higher loom speeds and the need to produce first quality fabrics with an absolute minimum in defects If the sizing is defective, the quality of the warp will be poor, which will affect the weaving operation . Treatment References 4. Winding, Warping, and Sizing 4.1 Introduction 4.2 Winding 4.3 Warping 4.4 Sizing 4.5 Single-End Sizing Systems 4.6 Draw-Warping and Sizing 4.7 Sizing of Different Yarns 4.8 Prewetting. yarn quality, sizing process, sizing materials and their evaluation, performance evaluation of sized yarn and the sizing process, and modern in- strumentation and control of the sizing machines their effects on sizing. Chapter 3 is devoted to the chemistry of sizing ingredients and their properties that determine suita- bility for applications. The importance of desizing and its effect