Edited byWilhelm AlbrechtHilmar FuchsWalter Kittelmann

Nonwoven Fabrics

InnodataFile Attachment3527605312.jpg

Nonwoven Fabrics

Edited byWilhelm Albrecht

Hilmar FuchsWalter Kittelmann

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Edited byWilhelm AlbrechtHilmar FuchsWalter Kittelmann

Nonwoven Fabrics

Editors

Prof. Dr. Wilhelm AlbrechtDr.-Tigges-Weg 3942115 WuppertalGermany

Prof. Dr.-Ing. Hilmar FuchsSächsisches Textilforschungsinstitut e.V.Annaberger Straße 24009125 ChemnitzGermany

Dr.-Ing. Walter KittelmannSächsisches Textilforschungsinstitut e.V.Annaberger Straße 24009125 ChemnitzGermany

Library of Congress Card No.: applied for

British Library Cataloguing-in-Publication DataA catalogue record for this book is available fromthe British Library.

Bibliographic information published byDie Deutsche BibliothekDie Deutsche Bibliothek lists this publicationin the Deutsche Nationalbibliografie; detailedbibliographic data is available in the Internet at

© 2003 WILEY-VCH Verlag GmbH & Co. KGaA,Weinheim

All rights reserved (including those of translationin other languages). No part of this book may bereproduced in any form – by photoprinting, mi-crofilm, or any other means – nor transmitted ortranslated into machine language without writtenpermission from the publishers. Registerednames, trademarks, etc. used in this book, evenwhen not specifically marked as such, are not tobe considered unprotected by law.

Printed in the Federal Republic of GermanyPrinted on acid-free paper

Composition K+V Fotosatz GmbH, BeerfeldenPrinting Strauss Offsetdruck GmbH,MörlenbachBookbinding Litges & Dopf BuchbindereiGmbH, Heppenheim

ISBN 3-527-30406-1

� This book was carefully produced. Nevertheless,editors, authors and publisher do not warrantthe information contained therein to be free oferrors. Readers are advised to keep in mind thatstatements, data, illustrations, procedural detailsor other items may inadvertently be inaccurate.

When in 1981 the world’s first authentic and complete handbook on Nonwovenswas published, the authors Albrecht and Lünenschloß already noted that these ini-tially relatively simple substitution products had become an independent and tech-nically sophisticated industry in its own right. Nonwovens owed their growth toan unusual multiplicity of raw materials and process options.

Since than 20 years have passed. Sales, distribution and diversity of an original-ly young and modest industry, whose focal points were clearly in Europe andUSA, have multiplied. Experts expect a worldwide production of approx. 3.3 mio.tons at a market value of approx. US$ 14.6 billion in the year 2000. This meansmore than 5% of conventional textile production will already be represented byNonwovens. In numerous market segments, Nonwovens already play a leadingrole. In certain areas they have assumed genuinely novel functions – for examplein textiles for personal and medical care.

Without doubt, the Nonwovens industry has also suffered during the course ofits 50-years maturing process. Several markets are not longer growing or do notallow economically acceptable returns on investment any more. In a number ofregions and market segments undiscriminating investments and the availability ofturn-key technology have done severe harm to the industry.

For the qualified and responsible producer, however, the Nonwovens industrycontinues to offer endless new challenges and opportunities. Not many otherfields of endeavour offer such creative diversity of raw materials and processes aswell as a limitless variety of finishing and application possibilities in order to ful-fil customer demands with tailor-made solutions. In this respect innovative Non-wovens producers can have confidence in a successful future.

In this spirit I welcome the new up-dated and extended version of the Nonwo-vens handbook and wish both, the authors and the publishers, the success theydeserve. We all shall stand to benefit.

H.N. Dahlström

V

Foreword

Twenty years ago, the reference book “Nonwovens” was kindly received by all con-cerned with textile manufacturing. In that book, more than 20 authors describedin detail the raw materials, their processing into a wide range of nonwoven prod-ucts, the characteristics of the products and the testing techniques then in use.“Nonwovens” was much asked for in industry, education and, with regard to newproducts, in R&D. Meanwhile, the quantity of nonwovens made worldwide hasgrown, the range of goods based on nonwovens is much wider, the technicalequipment, the raw materials as well as the auxiliaries used have been further de-veloped. Therefore, the idea did not come as a surprise to revise the book. Thismeant to find a team of authors fully conversant with the current state and thequantitative and qualitative developments going on in a field of industry which is– as hardly any other industry – run on a worldwide scale. A sophisticated projectlike this called for specialist co-ordination, which was provided by SächsischesTextilforschungsinstitut in Chemnitz, a research institute preferably dealing withquestions of nonwoven production and innovation in the field of nonwovens. Thisinstitute works closely together with companies that make or process nonwovensas well as with the suppliers of fibres, the manufacturers of the relevant equip-ment and the producers of auxiliaries, which has been very helpful.

Today, the nonwoven-producing industry is best characterized as an industrythat has accomplished a rise in product quality which the user can see and feel.Its range of products has become ever larger. This has been achieved by creativework and successful co-operation with the suppliers of raw and auxiliary materialsas well as the manufacturers of equipment. Based on this co-operation, there aregood prospects for novel products coming. Future developments will, in thewidest sense of the word, continue to focus on best-possible functionality and low-est-possible consumption of resources. To this end, it will be important all con-cerned work together even more closely. The editing team give their views of waysto go and aims to reach in the future in the last Chapter of this book headlined“outlook”, thus outlining the potential which is still waiting to be exploited. Thisbook is supposed to contribute to developing the nonwoven-producing industry.

We have been lucky one of the editing team has been in a position to do all thework in detail required to prepare this reference book. This meant spendingmuch time talking to the authors of the single Chapters and co-ordinating them.

VII

Preface

More help was provided by Wiley VCH Publishers, who will, except for the Ger-man edition, publish the book in English and Chinese, too. We are grateful to Dr.Böck for comprehensive advice. Thanks to her efforts, the book includes advertise-ment which will help the nonwoven-producing industry to deliver best quality andto develop new products. Our thanks go to all authors and those who have con-tributed in whatever way.

Today, nonwovens are part of what is known as the world of textiles. Due totheir tailor-made characteristics, they are highly suitable to meet a wide diversityof requirements. Thus, nonwovens are more than products which are up-to-date.They give evidence that it is possible to master the challenge of the future.

We hope the reader can make good use of this book.

Wilhelm AlbrechtHilmar FuchsWalter Kittelmann

PrefaceVIII

0 Introduction to nonwovens 10.1 Definition of nonwovens 10.2 Nonwoven manufacturing processes 30.3 Nonwoven properties and applications, including environmental

considerations 40.4 Development of the nonwovens industry 60.5 Future perspectives 11

Part I Raw materials for the production of nonwovens

1 Fibrous material 151.1 Natural fibres 151.1.1 Vegetable fibres 151.1.2 Animal fibres 201.2 Chemical fibres 211.2.1 Chemical fibres made from natural polymers 221.2.2 Man-made fibres from synthetic polymers 321.2.3 Modification of synthetic fibres 691.3 Other fibres made in industrial processes 741.3.1 Glass fibres 741.3.2 Silicate fibres 761.3.3 Carbon fibres 761.3.4 Boron fibres 761.3.5 Metal fibres 761.4 Reclaimed fibres 771.4.1 Basics 771.4.2 Making textile waste into reclaimed fibres 781.4.2.1 Pre-treatment 781.4.2.2 Principle of reclaiming 791.4.2.3 Subsequent treatment 801.4.3 Reclaimed fibre quality 801.4.4 Reclaimed fibre application 83

IX

Contents

2 Other raw materials 872.1 Cellulose (Pulp) 872.2 Granules 872.2.1 General discussion of physical properties 902.2.2 Polyolefins 922.2.3 Polyesters 932.2.4 Polyamides 942.3 Powders 962.3.1 Polymer powders 962.3.1.1 Polyacrylonitrile 962.3.1.2 Further copolymers 972.3.2 Additives 972.3.3 Stabilizers 982.3.4 Pigments 992.4 Absorbent polymers 1002.4.1 Absorption mechanism 1012.4.2 Production process 1012.4.2.1 Suspension polymerization 1012.4.2.2 Solution polymerization 1022.4.2.3 Surface crosslinking 1022.4.2.4 In-situ polymerization 1032.4.3 Test methods 1042.4.3.1 Characteristic data of absorbent polymer 1042.4.4 Field of application 1052.4.5 Summary 1062.5 Spin finishes 1062.5.1 General 1062.5.1.1 Definitions 1062.5.1.2 The requirements placed on spin finishes 1072.5.1.3 Compositions of spin finishes 1082.5.2 The application of spin finishes 1092.5.2.1 Man-made fibre production 1092.5.2.2 Processing 1102.5.3 Test methods 1102.5.3.1 Tests on the spin finishing agent 1102.5.3.2 Tests on spin finished fibre material 1112.5.4 Spin finishes on nonwovens 1132.5.4.1 General 1132.5.4.2 Nonwoven fabric manufacture and spin finishes 1132.5.4.3 End product and spin finish 1142.5.5 Future prospects 115

3 Binders 1193.1 Introduction 1193.2 Binder fluids 120

ContentsX

3.2.1 Chemical structure, construction principle 1213.2.1.1 Monomers 1213.2.1.2 Functional groups, crosslinking agents 1233.2.2 Binder fluids and their processing 1233.2.3 Binder fluids and the properties of nonwoven fabrics 1253.2.4 Focal points of development 1273.3 Adhesive fibres 1293.3.1 Soluble fibres 1293.3.2 Hotmelt adhesive fibres 1303.3.2.1 Appearance 1303.3.2.2 Chemical structure 1303.3.2.3 Mechanism of bonding 1343.3.2.4 Properties 136

Part II Processes to manufacture nonwovens

4 Dry-law process 1414.1 Nonwoven fabrics 1414.1.1 Fibre preparation 1414.1.2 Production of fibrous webs by carding 1484.1.2.1 Roller carding theory 1494.1.2.2 Plant technology 1574.1.2.3 Web forming 1594.1.2.4 Web drafting 1684.1.3 Fibre webs following the aerodynamic procedure 1704.1.3.1 Aim of the procedure 1704.1.3.2 Description of the procedure 1704.1.3.3 Machines for aerodynamic web forming 1744.1.4 Perpendicular laid fibrous highlofts STRUTO and ROTIS 1804.1.4.1 Technologies of production perpendicular laid highlofts 1814.1.4.2 Properties of perpendicular laid highlofts 1854.2 Extrusion nonwovens 1884.2.1 Use of polymers 1894.2.2 Generally, on the process technology and equipment to be used 1924.2.3 Processes to make spunlaid nonwovens and composites 2044.2.4 Processes to make fine-fibre spunbonded nonwovens 2214.2.4.1 Meltblowing process 2214.2.4.2 Flashspinning process 2244.2.4.3 Electrostatic spunbonding 2254.2.5 Processes to make film nonwovens 225

5 Wet lay method 2375.1 Principle of the method 2385.2 Development 2385.3 Raw materials and fibre preparation 239

Contents XI

5.3.1 Fibre types 2415.3.2 Production of short-staple fibres 2455.3.3 Binders 2455.3.4 Fibre preparation 2475.4 Construction of wet lay systems 2505.4.1 Web forming 2565.4.2 Bonding 2625.4.2.1 Adding the binder fibres 2625.4.2.2 Adding binder dispersions to the pulp 2625.4.2.3 Adding the binder to nonwoven web 2635.4.2.4 Pressing 2645.4.3 Web drying 2655.4.3.1 Contact drying 2655.4.3.2 Circulating-air dryers 2655.4.3.3 Tunnel dryers 2665.4.3.4 Radiation drying 2665.4.4 Batching 266

6 Web bonding 2696.1 Needling process 2706.1.1 The principle of needling 2706.1.1.1 Batt feeding 2726.1.1.2 Needling zone 2736.1.1.3 Felt removal 2826.1.2 High-performance needling technique 2826.1.3 Surface structuring 2836.1.4 Paper machine clothing 2866.1.5 Needle characteristics 2896.1.6 Influence of needling conditions on the needle felt’s

293

6.2 Loop formation processes 3026.2.1 System of processes 3046.2.1.1 Stitch-bonding processes 3056.2.1.2 Stitch-bonding process Malivlies 3126.2.1.3 Pile stitch-bonding process with base material 3186.2.1.4 Loop stitch-bonding without base material 3206.2.1.5 Loop stitch-bonding with double-sided meshing 3216.2.1.6 Loop stitch-bonding to bond two fabrics by meshing 3236.2.2 Warp knitting 3246.2.3 Knitting 3256.3 Hydroentanglement process 3266.3.1 Process development 3276.3.2 Fibre and process influences 3346.3.3 Bonding lines 3366.4 Thermal processes 341

ContentsXII

characteristics

6.4.1 Drying 3416.4.1.1 Convection drying 3426.4.1.2 Contact drying 3526.4.1.3 Radiation drying 3536.4.2 Hot-air bonding 3536.4.2.1 Basics 3536.4.2.2 Process technology 3556.4.2.3 Line technology 3596.4.3 Heatsetting 3616.4.4 Thermal calender bonding 3636.4.4.1 Process technology 3646.4.4.2 Line technology 3676.4.5 Ultrasound bonding 3696.5 Chemical methods 3696.5.1 Introduction 3696.5.2 Methods for cohesive bonding 3726.5.2.1 Cohesive bonding through thermoplasticity 3726.5.2.2 Cohesive bonding in the case of a dissolved fibre surface 3726.5.3 Adhesive bonding methods 3736.5.3.1 Application of liquid binder in excess 3746.5.3.2 Removal of excess liquor 3766.5.3.3 Metered binder application to one side 3786.5.3.4 Application of foamed binder fluids 3846.5.3.5 Application of powder 3866.6 Composite materials 3896.6.1 Nonwoven composites 3896.6.1.1 Variants of processes 3906.6.1.2 Bonding by means of needle-punching 3916.6.1.3 Bonding by means of stitch-bonding 3936.6.1.4 Bonding by means of entangling 3946.6.1.5 Bonding by means of glueing 3956.6.2 Nonwovens suitable to make composite materials 398

Part III Finishing nonwovens

7 Mechanical finishing 4117.1 Shrinking 4117.1.1 Creation and removal of distortions 4117.1.2 Deliberate shrinkage 4117.2 Compacting and creping 4127.2.1 Compacting – the Clupak process 4127.2.2. Creping – the Micrex microcrepe process 4137.3 Glazing, calendering, pressing 4147.3.1 Glazing or rolling calenders 4147.3.2 Embossing or goffering calenders 414

Contents XIII

7.3.3 Felt calenders, transfer calenders 4157.3.4 Rotary pressing machines 4157.3.5 Moulding, stamping 4157.4 Perforating, slitting, breaking 4167.4.1 Perforating 4167.4.2 Slitting 4167.4.3 Breaking 4177.5 Splitting, emerizing, suede finishing, shearing, raising 4177.5.1 Splitting 4177.5.2 Emerizing, suede finishing 4187.5.3 Shearing, raising 4187.6 Singeing 4187.7 Sewing, quilting and welding 4197.7.1 Cover-seaming and quilting 4197.7.2 Ultrasonic welding 4197.7.3 High-frequency welding 4197.8 Other mechanical finishing methods 420

8 Chemical finishing 4218.1 Washing 4218.2 Dyeing 4228.2.1 Stock and spin dyeing 4228.2.2 Dyeing and bonding 4238.2.3 Subsequent dyeing 4238.2.4 Different dyeing methods 4248.2.5 Cold pad batch dyeing 4248.2.6 Continuous dyeing 4258.3 Printing 4258.3.1 Printing of lightweight nonwovens 4258.3.2 Printing of heavy nonwovens (needle-punched nonwoven

floor coverings) 4268.3.3 Spray printing 4278.3.4 Transfer printing 4288.4 Finishing, softening, special effects 4288.4.1 Machine facts and possibilities 4298.4.2 Stiffening finishes 4298.4.2.1 Finishing of toe and heel caps on footwear 4298.4.2.2 Finishing of nonwovens for roofing felts 4308.4.2.3 Finishing of glass fibre nonwovens for glass fibre composites 4308.4.3 Softening 4308.4.4 Antistatic finishing 4318.4.5 Soil-repellent finishing 4328.4.6 Water-repellent and oil-repellent finishing 4328.4.7 Hygiene finishing 4328.4.8 Flame resistant finishing 433

ContentsXIV

8.4.9 Absorbent and water absorbent finishing 4338.4.10 Dust-bonding treatment 4348.5 Coating 4358.5.1 Coating methods 4358.5.1.1 Kiss roll coating 4358.5.1.2 Rotogravure coating 4368.5.1.3 Rotary screen coating 4368.5.1.4 Knife or doctor coating 4378.5.1.5 Extrusion coating 4388.5.1.6 Non-contact coating 4398.5.1.7 Release coating 4398.5.2 Coating effects 4408.5.2.1 Non-slip finishing 4408.5.2.2 Mouldable coating 4418.5.2.3 Self-adhesive coating 4418.5.2.4 Foam coating 4428.5.2.5 Loose lay coating 4458.5.2.6 Microporous coating 4468.5.2.7 Drainage coating 4468.5.2.8 Heat-sealing coating 4478.6 Laminating 4508.6.1 Wet laminating 4518.6.2 Dry laminating 4518.6.2.1 Use of adhesive nonwovens 4528.6.3 Examples of laminating 4528.7 Flocking 4548.8 New processes and products 4558.9 Ecology and economy 456

Part IV Peculiarities with regard to ready-making nonwovens

9 The making up of finished products 4639.1 Concepts and definitions 4639.2 Product development 4659.2.1 Product development for garment textiles 4659.2.2 Product development for decor fabrics and home textiles 4689.2.3 Product development for technical textiles 4689.3 Production preparation 4699.4 Production 4719.4.1 Spreading 4719.4.2 Cutting 4729.4.3 Joining and assembly 4779.4.4 Ironing 4829.5 Packaging 4839.6 Mechanization and automation 483

Contents XV

Part V Characteristics and application of nonwovens

10 Nonwovens for hygiene 489

11 The use of nonwovens in medicine – safety aspects 49511.1 General requirements 49911.2 Design and construction 50011.3 Information to the user 50111.4 Conclusion 502

12 Nonwovens for cleaning and household products 50312.1 Market situation 50312.2 Wet and damp-cleaning products 50412.2.1 Floor cloths and materials for floor cleaning systems 50612.2.2 Durable wiping cloths 50712.2.3 Disposable and semi-disposable wiping cloths 50712.2.4 Synthetic leather (Chamois type) 50912.3 Dry and damp-cleaning products 50912.3.1 Microfibre nonwovens 50912.3.2 Polyvinyl alcohol nonwovens 51112.3.3 Impregnated cloths 51112.4 Scouring media 51112.4.1 Pan scourers, scouring sponges and pads 51212.4.2 Floor pads 512

13 Nonwovens for home textiles 51513.1 Nonwovens for upholstery material 51513.2 Nonwovens for floorcoverings 51713.3 Nonwoven fabrics for wallcoverings 51913.4 Nonwoven fabrics as furnishing fabrics 52013.5 Tufting substrate 520

14 Nonwovens for apparel 52314.1 Nonwoven interlinings 52314.1.1 Introduction 52314.1.2 History of nonwoven interlinings 52314.1.3 Functions of nonwoven interlinings 52414.1.3.1 Interlining fabric for shaping and support 52414.1.3.2 Nonwoven interlining for stabilizing and/or stiffening 52514.1.3.3 Nonwoven interlinings for providing bulk 52514.1.4 Properties of nonwoven interlinings 52514.1.5 Functional elements of nonwoven interlinings 52714.1.6 Outlook 52814.2 Nonwovens for protective clothing 52814.3 Nonwoven support materials for footwear 536

ContentsXVI

15 Nonwovens for technical applications 54515.1 Insulation 54515.1.1 Fire, heat, sound 54515.1.2 Electrical insulation 55415.2 Filtration 55715.2.1 Dry filtration 56015.2.1.1 General 56015.2.1.2 Functional requirements properties 56215.2.1.3 Surface filters 56315.2.1.4 Depth filters 56815.2.2 Liquid filtration 57015.2.2.1 Liquid filters based on nonwovens 57215.2.2.2 Variables in design of liquid filters 57315.3 Building and construction industry 57615.3.1 Geononwovens 57615.3.1.1 Functions and requirements 57815.3.1.2 Selected examples of the uses of nonwovens 58115.3.1.3 Outlook 58415.3.2 Bituminous roofing membranes 58615.3.2.1 Introduction 58615.3.2.2 Market overview 58715.3.2.3 The bituminization of polyester nonwovens 58815.3.2.4 The end use requirements of membranes with polyester inlay 59015.3.2.5 Trends and developments 59215.4 Agriculture 59315.4.1 Introduction 59315.4.2 Requirements to be met by agricultural nonwovens 59415.4.3 Technological processes 59515.4.4 Application 59515.4.5 Market trends 59715.5 The motor vehicle industry 59815.5.1 The market 59815.5.2 The car industry 59915.5.2.1 Required characteristics 60115.5.2.2 Acoustic and thermal insulation – inside the car 60515.5.2.3 Acoustic and thermal insulation – the engine housing 60715.5.2.4 Covering materials – interior of the car 60715.5.2.5 Nonwovens for seat cushioning and laminated nonwovens 61015.5.2.6 Automotive filter fabrics 61215.5.2.7 Nonwovens as backing substrates, microfibre webs and other

nonwovens 61515.5.3 The aircraft, shipbuilding and railways industries 61615.5.4 Outlook 61715.6 Papermaking fabrics 617

Contents XVII

16 Re-utilization of nonwovens 62916.1 Waste from the production of nonwovens 62916.1.1 Measures to reduce waste 63016.2 Used waste of nonwoven materials 63016.2.1 Disposables 63016.2.2 Long-life products 63116.3 Utilization of nonwoven waste 63116.3.1 Mechanical processes to recover fibres 63116.3.2 Re-granulation 63116.3.3 Production of textile chips and their application 63216.3.4 Processing nonwoven waste on KEMAFIL machines 63216.3.5 Re-use of nonwoven waste 633

Part VI Regulations to be observed and processes to test raw materialsand nonwoven products

17 General priciples 63717.1 Sampling and statistics 63717.2 Testing climate 63817.3 Standards and specifications 638

18 Testing processes 66118.1 Raw materials for nonwovens 66118.1.1 Fibres 66118.1.2 Granulates 66818.1.3 Binders 66918.2 Nonwovens 67018.2.1 Textile-physical tests 67018.2.2 Fastness testing 68118.2.3 Testing of burning behaviour 68718.2.4 Testing of the behaviour during laundering/dry cleaning 69418.2.5 Human ecological tests 69418.3 Test processes relating to end-use 69618.3.1 Hygiene and medical products 69618.3.2 Cleaning cloths and household products 69718.3.3 Household textiles 69818.3.4 Protective clothing 69918.3.5 Filter fabrics 70318.3.6 Geononwovens 708

19 Quality surveillance systems and quality assurance systems 717

20 Coming development in nonwovens industry 727

Index of names, companies, organizations, and products 731

Subject index 737

ContentsXVIII

XIX

List of editors and authors

Editors

Prof. Dr. Wilhelm AlbrechtDr. Tigges-Weg 3942115 WuppertalGermany

Prof. Dr.-Ing. Hilmar FuchsSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dr.-Ing. Walter KittelmannH.-Greif-Straße 3501217 DresdenGermany

Authors

Dr.-Ing. Klaus AfflerbachVoith Paper GmbH & Co. KGRavensburgBetriebsstätte DürenVeldener Straße 5253349 DürenGermany

Dipl.-Ing. Hans-Claus AssentAlbert-Ludwig-Grimm-Straße 1869469 WeinheimGermany

Lutz BergmannP.O. Box 2189La Grange, GA 30241-2189USA

Dipl.-Ing. Siegfried BernhardtSpinnbau GmbHP.O. Box 71 03 6028763 BremenGermany

Dipl.-Ing. Uta BernsteinSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dr. Walther BestThomas Joseph Heimbach GmbH & Co.Gut Nazareth52353 DürenGermany

Dipl.-Ing. Bettina BieberSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dipl.-Ing. Dieter BlechschmidtSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

List of editors and authorsXX

Dr.-Ing. Peter BöttcherSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dipl.-Ing. Margot BrodtkaSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

H. Norbert DahlströmFreudenberg & Co.P.O. Box 10 03 6369465 WeinheimGermany

Dipl.-Ing. Johann Philipp DiloOSKAR DILO Maschinenfabrik KGP.O. Box 155169405 EberbachGermany

Dr.-Ing. Waldemar DohrnBGB Stockhausen GmbH & Co. KGP.O. Box 10 04 5247705 KrefeldGermany

Dr.-Ing. Peter EhrlerBergstraße 1901069 DresdenGermany

Dr. Ir. J. J. FrijlinkBerkenweg 183941 JB DoornThe Netherlands

Dr. Rainer GebhardtSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dipl.-Ing. Bernd GulichSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dr.-Ing. Victor P. GuptaOSKAR DILO Maschinenfabrik KGP.O. Box 155169405 EberbachGermany

Dr. Rainer GutmannInstitut für Chemiefasern der DITFKörschtalstraße 2675770 DenkendorfGermany

Dipl.-Phys. Jürgen HaaseSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dr. Jan HobornSCA Mölniycke Clinical Products ABBakstensgatan 540503 GöteborgSweden

Prof. Ji GuobiaoChina National Textile Council12 East Chang An St.100742 BeijingChina

Prof. Dr.-Ing. Radko Krčma�

Dr.-Ing. Peter KunathOSKAR DILO Maschinenfabrik KGP.O. Box 155169405 EberbachGermany

List of editors and authors XXI

Dipl.-Ing. Ferdinand LeifeldVon-Behring-Straße 3447906 KempenGermany

Dipl.-Ing. Catrin LewickiSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Prof. Dr.-Ing. Klaus LieberenzOberonstraße 8d01259 DresdenGermany

Dr.-Ing. Matthias MägelSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dipl.-Ing. Sabine MartiniKirchplatz 2447918 TönisvorstGermany

Guy Massenaux26, rue V. Greyson1050 BrusselsBelgium

Dipl.-Chem. Wolfgang MöschlerRosentor 1809126 ChemnitzGermany

Dr.-Ing. Ullrich MünstermannFLEISSNER GmbH & Co.MaschinenfabrikWolfsgartenstraße 663329 EgelsbachGermany

Dipl.-Ing. Ansgar PaschenInstitut für Textiltechnikder RWTH AachenEilfschornsteinstraße 1852062 AachenGermany

Dr. Thomas PfüllerSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Helmuth PillPILL NaßvliestechnikHeilbronner Straße 27472760 ReutlingenGermany

Dipl.-Ing. Norbert RitterFLEISSNER GmbH & Co.MaschinenfabrikWolfsgartenstraße 663329 EgelsbachGermany

Prof. Dr. Hartmut RödelInstitut für Textil- undBekleidungstechnik der TU Dresden01062 DresdenGermany

Dipl.-Ing. Manfred Sauer-KunzeGEA Delbag – Lufttechnik GmbHSüdstraße 4844625 HerneGermany

Dipl.-Ing. Manfred SchäfflerAUTEFA Maschinenfabrik GmbHRöntgenstraße 1–586316 FriedbergGermany

List of editors and authorsXXII

Dipl.-Chem. Wolfgang SchildeSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dipl.-Ing. Elke SchmalzSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

Dipl.-Ing. Gunter SchmidtFinkenweg 2279312 EmmendingenGermany

Dipl.-Ing. Jochen SchreiberSächsisches Textilforschungsinstitut e.V.P.O. Box 132509072 ChemnitzGermany

J.M. SlovačekColbond Nonwovens73 Westervoortsedijk6800 TC ArnheimThe Netherlands

Dr. Jürgen SpindlerEMS-CHEMIE AG7013 Domat-EmsSwitzerland

Wolfgang SteinStrassberger Straße 604288 LeipzigGermany

Prof. Dr. Michael StollForschungsinstitut für Leder undKunstledertechnologie gGmbHP.O. Box 11 4409581 FreibergGermany

Karl-Heinz StukenbrockPanoramaweg 2541334 NettetalGermany

Dipl.-Ing. Alfred WatzlFLEISSNER GmbH & Co.MaschinenfabrikWolfsgartenstraße 663329 EgelsbachGermany

Dipl.-Ing. Alexander WegnerKARL MAYER MalimoTextilmaschinenfabrik GmbHP.O. Box 71309007 ChemnitzGermany

Dr. Jochen WirschingFREUDENBERGHaushaltprodukte KGCorporate Technical CentreZwischen Dämmen, Bau 14869465 WeinheimGermany

Prof. Dr.-Ing. Burkhard WulfhorstRolandstraße 37 A52223 StollbergGermany

Dipl.-Ing. Walter ZähKARL MAYERTextilmaschinenfabrik GmbHBrühl 2563179 ObertshausenGermany

Chapter/Section Translator

0 Guy Massenaux

1.1 to 1.3 Irene Mühldorf (Team Coordinator)1.2 Ji Guobiao1.4 Harald Linke

2.1 Harald Linke2.2, 2.3 Rainer Gutmann2.4 Sabine Martini2.5 Waldemar Dohrn

3.1, 3.2 George Noot3.3 Jürgen Spindler

4.1.1 Annemaria Köhler4.1.2 George Noot4.1.3 Annemaria Köhler4.1.4 Oldřich Jirsák4.2 Harald Linke

5 George Noot

6 Andrea Wunder6.1 Andrea Wunder6.2 Harald Linke6.3, 6.4 Marie-Luise Moldenhauer6.5 George Noot6.6 Harald Linke

7, 8 Alison Sanders

9 Hartmut Rödel

10 Alison Sanders

XXIII

This book was translated by:

Chapter/Section Translator

11 Jan Hoborn

12 Jochen Wirsching

13.1 to 13.4 George Noot13.5 Patricia van der Horst

14.1, 14.2 Alison Sanders14.3 Michael Stoll

15.1 Alison Sanders15.2 Elke Schmalz, Lutz Bergmann15.3.1 Jacqueline Borstnik Billingsley15.3.2 J. J. Frijlink15.4 Harald Linke15.5 Jacqueline Borstnik Billingsley15.6 Jacqueline Borstnik Billingsley

16 Harald Linke

17, 18 Jacqueline Borstnik Billingsley

19 Marie-Luise Moldenhauer

20 Harald Linke

TranslatorsXXIV

Whilst the first production of a “nonwoven fabric” in Europe goes back to the thir-ties, the existence of a recognizable nonwovens industry in Europe can be datedto the mid-sixties.

This is also when the terms nonwovens or Vliesstoffe got used, preferably toothers, in a small circle of manufacturers and converters.

Since then, the manufacture of nonwovens has expanded rapidly and the use ofsuch products has penetrated many aspects of industry and of private life. Non-wovens are found in hygiene and health care, in rooting and civil engineering,household and automotive, in cleaning, filtration, clothing, food wrap and pack-aging, to name only a few end-uses. Confusion or ignorance about nonwovens re-mains large though. The present book comes out therefore at the right time togive a comprehensive view of what is to be understood by nonwovens, their man-ufacturing process, applications and possibilities. Presenting in a coherent waythe present state of the art of nonwovens manufacturing and end-uses will be aninvaluable help to all those within the industry or outside of it who deal with non-wovens or might get the opportunity to do so.

It is to be hoped that this book will also have a seminal influence in attractingyoung talents to this growing industry, where so much still is needed in order tofurther develop machinery, raw materials and properties of nonwovens to theirbest use.

0.1Definition of nonwovens

The term used to designate the products generally known as nonwovens, wascoined in most languages in opposition to woven fabrics, which implicitly weretaken as a reference. A nonwoven was something that was not woven.

Even the German name “Vliesstoffe” wasn’t clear either as it could be confusedwith ceramical material and in any case remained ambiguous in its unusual spel-ling. Only specialists know that nonwovens are unique engineered fabrics whichoffer cost effective solutions as e.g. in hygiene convenience items, or as battery se-parators, or filters, or geotextiles, etc.

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0

Introduction to nonwovensG. Massenaux

There is a formal definition of Nonwoven: ISO 9092 1) which bas been adoptedby CEN (EN 29092) and consequently by DIN or AFNOR or any standardizationoffice in the EU. Various legal or regulatory implications derive from it 2).

As a main characteristic the CEN definition indicates that a nonwoven is a fab-ric made of fibres, that is consolidated in different ways. Nonwoven fabrics aremade out of fibres, without any restriction, but not necessarily from fibres. Thesecan be very short fibres of a few millimetres length as in the wetlaid process;these can be “ordinary” fibres, as used in the traditional textile industry, or thenvery long filaments etc. Properties and characteristics of a nonwoven fabric de-pend for a large part from the type of fibre it is ultimately made of. These fibrescan be natural or man-made, organic or inorganic; the characteristic of a fibrebeing that it is longer than its thickness, or diameter. Such fibres can also be pro-duced continuously in connection with the nonwoven process itself and then cutto length, or then extruded directly e.g. from polymer granules into a filamentand then fibrous structure.

To make good measure the ISO definition also excludes various types of fabricsto which, voluntarily or not, one might compare nonwovens. Nonwovens are notpaper and indeed, when made out of very short, cellulose fibres, they essentiallydiffer from paper because there aren’t any, or hardly, hydrogen bonds linking suchfibres together3).

Nonwovens, as indicated by their English or French name, are neither wovenfabrics, nor such other textiles as knitted fabrics. Behind these statements lies afundamental characteristic of nonwoven: contrary to woven or knitted fabrics,fibres that ultimately make up the nonwoven fabric need not to go through thepreparatory/transitory stage of yarn spinning in order to be transformed into aweb of a certain pattern.

Some will remark that other textile fabrics were created in the past besides theweaving and knitting process, e.g. felting (which is also yarnless) or more recentlystitchbonding. For this reason as well – especially in the early days – some havetended to literally classify as nonwovens all textile fabrics that are outside theweaving/knitting domain. Matters have settled since then and the reflexions at

0 Introduction to nonwovens2

1) A manufactured sheet, web or batt of directionally or randomly orientated fibres, bonded by fric-tion, and/or cohesion and/or adhesion, excluding paper and products which are woven, knitted,tufted, stitch-bonded incorporating binding yarns or filaments, or felted by wet-milling, whether ornot additionally needled. The fibres may be of natural or man-made origin. They may be staple orcontinuous filaments or be formed in situ. (This definition is completed by various notes.)

2) The CEN nonwovens definition is adopted by EDANA, the European nonwovens industry associa-tion. INDA, the North American Association has a slightly different, wider definition which hasthe merit of apparent simplicity: a sheet, web or batt of natural and or man-made fibres or fila-ments excluding paper, that have not been converted into yarns and that are bonded together byany of several means (such means are then listed).

3) There remain marginal cases with respect to paper or other fabrics which the ISO/CEN definitiontries to deal with in its notes but we won’t bother the reader with it. Like in nature there are someareas which can be contested between sea and terra firma and where the final accepted limit issomewhat arbitrary; or like in the plant/animal realm where the final distinction depends fromthe criteria that are finally adopted . . .

ISO and CEN helped clarify this. As far as textiles go, nonwovens are only part ofa category of fabrics that exist besides weaving and knitting.

Nonwovens though go also beyond the limits of textiles. Fibres they ultimatelyare made of can be very short “unspinnable” ones like in the paper industry; thefibrous web can also originate from foils and other plastics. Nonwovens thereforeshare for a part manufacturing characteristics and properties with the paper in-dustry or the chemicals/plastics industry to finally make a world of their own.

Nonwovens do not depend on the interlacing of yarn for internal cohesion. In-trinsically they have neither an organized geometrical structure. They are essen-tially the result of the relationship between one single fibre and another. This pro-vides nonwoven fabrics with characteristics of their own, with new or better prop-erties (absorption, filtration) and therefore opens them up to other applications.

0.2Nonwoven manufacturing processes

There are three main routes to web forming:

– the drylaid system with carding or airlaying as a way to form the web;– the wetlaid system;– the polymer-based system, which includes spunlaying (spunbonding) or

specialized technologies like meltblown, or flashspun fabrics etc.

The lack of sufficient frictional forces however bas to be compensated for by thebonding of the fibres, which provides web strength. Consolidation of the webafter its formation is the second step in the nonwoven manufacturing process.

This consolidation for a large part sets the final characteristics of the fabric andtherefore, if possible, ought to be chosen with the end application in mind. Suchconsolidation can be done by use of chemical means (chemical bonding) like bin-ders. These can be applied uniformly by impregnating, coating or spraying or in-termittently, as in print bonding. The consolidation can also be reached by ther-mal means (cohesion bonding), like the partial fusion of the constituting fibres orfilaments. Such fusion can be achieved e.g. by calendering or through-air blowingor by ultra-sonic impact.

Finally, consolidation can be achieved by mechanical means (frictional bond-ing), like needling, stitching, water-jet entangling or a combination of these var-ious means.

Customers needs can be further met by modifying or adding to the existingproperties of the fabric through finishing. A variety of chemical substances can beemployed before or after bonding or various mechanical processes can be appliedto the nonwoven in the final stage of the manufacturing process.

The choice of the raw material and the final constituting fibrous element, thedepositing of the fibres as a fibrous material of a varying density, the choice ofconsolidating and finishing means, all this creates a series of parameters whichcan be played with in order to reach the required properties. This confirms what

0.2 Nonwoven manufacturing processes 3

was indicated earlier that nonwovens are engineered fabrics par excellence. Wheningredients, web formation and consolidation are chosen in order to best meetthe characteristics needed at the end application, then for sure, we have a winner.

0.3Nonwoven properties and applications, including environmental considerations

Nonwovens are in fact products in their own right with their own characteristicsand performances, but also weaknesses. They are around us and one uses themeveryday, often without knowing it. Indeed they are frequently hidden from view.Nonwovens can be made absorbent, breathable, drapeable, flame resistant, heatsealable, light, lint-free, mouldable, soft, stable, stiff, tear resistant, water repel-lent, if needed. Obviously though, not all the properties mentioned can be com-bined in a single nonwoven, particularly those that are contradictory.

Their applications are multifold. Examples of their uses can be listed as follows:

� Personal care and hygiene as in baby diapers, feminine hygiene products, adultincontinence items, dry and wet pads, but also nursing pads or nasal strips.

� Healthcare, like operation drapes, gowns and packs, face masks, dressings andswabs, osteomy bag liners, etc.

� Clothing: interlinings, insulation and protection clothing, industrial workwear,chemical defence suits, shoe components, etc.

� Home: wipes and dusters, tea and coffee bags, fabric softeners, food wraps, fil-ters, bed and table linen, etc.

� Automotive: boot liners, shelf trim, oil and cabin air filters, moulded bonnetliners, heat shields, airbags, tapes, decorative fabrics, etc.

� Construction: roofing and tile underlay, thermal and noise insulation, housewrap, underslating, drainage, etc.

� Geotextiles: asphalt overlay, soil stabilization, drainage, sedimentation and ero-sion control, etc.

� Filtration: air and gas, Hevac, Hepa, Ulpa filters� Industrial: cable insulation, abrasives, reinforced plastics, battery separators,

satellite dishes, artificial leather, air conditioning, coating.� Agriculture, home furnishing, leisure and travel, school and office etc.

The origins of nonwovens are not glamorous. In fact, they resulted from recyclingfibrous waste or second quality fibres left over from industrial processes like weav-ing or leather processing. They also resulted from raw materials restrictions e.g.during and after the Second World War or later in the communist dominatedcountries in Central Europe. This humble and cost dominated origin of courselead to some technical and marketing mistakes; it is also largely responsible fortwo still lingering misconceptions about nonwovens: they are assumed to be(cheap) substitutes; many also associate them with disposable products and forthat reason did consider nonwovens as cheap, low quality, items.

0 Introduction to nonwovens4