Contents
Preface ……………………………………………………………………………………………………. 1
1 Historical Background …………………………………………………………………………. 3
Introduction ……………………………………………………………………………………….. 3
1.1 The Textile Industry …………………………………………………………………….. 3
1.2 The Rubber Industry……………………………………………………………………. 6
1.3 Textile and Rubber Composites …………………………………………………… 10
References ………………………………………………………………………………………… 13
2 Production and Properties of Textile Yarns ……………………………………………. 15
Introduction ……………………………………………………………………………………… 15
2.1 Production Methods for Textile Fibres …………………………………………. 15
2.1.1 Cotton ………………………………………………………………………….. 15
2.1.2 Rayon …………………………………………………………………………… 21
2.1.3 Nylon …………………………………………………………………………… 24
2.1.4 Polyester ……………………………………………………………………….. 26
2.1.5 Aramid …………………………………………………………………………. 28
2.2 General Characteristics of Textile Fibres ………………………………………….. 30
2.2.1 Cotton ………………………………………………………………………….. 30
2.2.2 Rayon …………………………………………………………………………… 32
2.2.3 Nylon …………………………………………………………………………… 33
2.2.4 Polyester ……………………………………………………………………….. 34
2.2.5 Aramid …………………………………………………………………………. 35
2.3 General Physical Properties of Textile Fibres …………………………………. 36
2.3.1 Cotton ………………………………………………………………………….. 36
2.3.2 Rayon …………………………………………………………………………… 38
2.3.3 Nylon …………………………………………………………………………… 39
2.3.4 Polyester ……………………………………………………………………….. 40
2.3.5 Aramid …………………………………………………………………………. 40
References ………………………………………………………………………………………… 40
3 Yarn and Cord Processes …………………………………………………………………….. 41
Introduction ……………………………………………………………………………………… 41
3.1 Yarn Preparation Methods………………………………………………………….. 41
3.1.1 Twisting ………………………………………………………………………… 42
3.1.2 Texturing ………………………………………………………………………. 49
3.2 Warp Preparation ……………………………………………………………………… 52
3.2.1 Direct Warping ………………………………………………………………. 53
3.2.2 Sectional Warping …………………………………………………………… 54
3.3 Sizing …………………………………………………………………………………………. 57
4 Fabric Formation and Design of Fabrics ……………………………………………….. 59
Introduction ……………………………………………………………………………………… 59
4.1 Fabric Formation ………………………………………………………………………. 59
4.1.1 Weaving ………………………………………………………………………… 59
4.1.2 Knitting ………………………………………………………………………… 64
4.1.3 Non-Woven Fabrics ………………………………………………………… 68
4.2 The Design of Woven Fabrics ……………………………………………………… 70
4.2.1 Physical Property Requirements………………………………………… 70
4.2.2 Selection of Fibre Type…………………………………………………….. 71
4.2.3 Selection of Fabric Construction ……………………………………….. 74
5 Heat-Setting and Adhesive Treatments ………………………………………………….. 83
Introduction ……………………………………………………………………………………… 83
5.1 Heat-Setting Machinery ……………………………………………………………… 83
5.2 Heat-Setting ……………………………………………………………………………… 90
5.3 Adhesive Treatment …………………………………………………………………… 94
5.3.1 Cotton ………………………………………………………………………….. 94
5.3.2 Rayon …………………………………………………………………………… 95
5.3.3 Nylon …………………………………………………………………………… 98
5.3.4 Polyester ……………………………………………………………………….. 99
5.3.5 Aramid ……………………………………………………………………….. 101
5.4 The In Situ Bonding System ………………………………………………………. 102
5.5 Mechanisms of Adhesion ………………………………………………………….. 103
5.6 Environmental Factors Affecting Adhesion ………………………………….. 107
Appendix V Interfacial Compatibility …………………………………………………. 109
References ………………………………………………………………………………………. 112
6 Basic Rubber Compounding and Composite Assembly ………………………….. 113
6.1 Compounding …………………………………………………………………………. 113
6.1.1 Polymers ……………………………………………………………………… 113
6.1.2 Curing Systems …………………………………………………………….. 114
6.1.3 Fillers ………………………………………………………………………….. 116
6.1.4 Antidegradants …………………………………………………………….. 117
6.1.5 Other Compounding Ingredients …………………………………….. 117
6.2 Processing ………………………………………………………………………………. 117
6.3 Composite Assembly………………………………………………………………… 118
6.3.1 Calendering …………………………………………………………………. 118
6.3.2 Coating ……………………………………………………………………….. 124
References ………………………………………………………………………………………. 127
7 Assessment of Adhesion ……………………………………………………………………. 129
Introduction ……………………………………………………………………………………. 129
7.1 Cord Tests ………………………………………………………………………………. 129
7.1.1 Pull-Out Tests ………………………………………………………………. 130
7.1.2 Cord Peel Test ………………………………………………………………. 130
7.2 Fabric Test Methods ………………………………………………………………… 133
7.3 Testing and Interpretation of Results ………………………………………….. 138
7.4 Adhesion Tests for Lightweight Fabrics and Coatings……………………. 140
7.5 Peeling by Dead-Weight Loading ……………………………………………….. 142
7.6 Direct Tension Testing of Adhesion ……………………………………………. 143
7.7 Adhesion and Fatigue Testing ……………………………………………………. 145
7.8 Assessment of Penetration into the Textile Structure ……………………… 146
Appendix VII: The Physics of Peeling ………………………………………………….. 148
References ………………………………………………………………………………………. 153
8 Conveyor Belting …………………………………………………………………………….. 155
Introduction ……………………………………………………………………………………. 155
8.1 Belt Construction and Operation ……………………………………………….. 160
8.1.1 Carcase ……………………………………………………………………….. 160
8.1.2 Insulation …………………………………………………………………….. 161
8.1.3 Covers ………………………………………………………………………… 162
8.2 Belt Design ……………………………………………………………………………… 165
8.2.1 Plied Belting …………………………………………………………………. 167
8.2.2 Single-Ply and Solid-Woven Belting …………………………………. 171
8.2.3 Steel Cord Belting ……………………………………………………………. 172
8.3 Belting Manufacture ………………………………………………………………… 172
8.3.1 Belt Building ………………………………………………………………… 173
8.3.2 Pressing and Curing ………………………………………………………. 173
8.3.3 Belt Joining ………………………………………………………………….. 178
8.4 Belt Testing …………………………………………………………………………….. 182
8.4.1 Tensile Strength and Elongation ……………………………… 182
8.4.2 Gauge ………………………………………………………………… 183
8.4.3 Adhesion ……………………………………………………………. 183
8.4.4 Abrasion …………………………………………………………….. 183
8.4.5 Troughability ………………………………………………………. 183
8.4.6 Fire Resistance …………………………………………………….. 183
References ………………………………………………………………………………………. 184
9 Hose………………………………………………………………………………………………. 187
Introduction ……………………………………………………………………………………. 187
9.1 Hose Manufacture …………………………………………………………………… 188
9.1.1 Braiding ………………………………………………………………………. 188
9.1.2 Spiralling …………………………………………………………………….. 190
9.1.3 Wrapped Hose ……………………………………………………………… 191
9.1.4 Knitted Hose………………………………………………………………… 192
9.1.5 Oil Suction and Discharge Hose ……………………………………… 192
9.1.6 Circular Woven Hose…………………………………………………….. 193
Appendix IX …………………………………………………………………………………… 195
i. Neutral Angle ………………………………………………………………………. 195
ii. Bursting Pressure …………………………………………………………….. 196
10 Power Transmission Belts ………………………………………………………………….. 199
Introduction ……………………………………………………………………………………. 199
10.1 Main Types of Power Transmission Belts …………………………………….. 200
10.1.1 V-Belts ………………………………………………………………………… 200
10.1.2 Timing Belts …………………………………………………………………. 203
10.1.3 Flat Belting ………………………………………………………………….. 203
10.1.4 Cut-Length Belting………………………………………………………… 205
10.2 Manufacture of Power Transmission Belting ……………………………….. 206
10.2.1 Manufacture of V-Belts ………………………………………………….. 206
10.2.2 Manufacture of Timing Belts ………………………………………….. 209
10.3 Effect of the Textile Reinforcement on Belt Performance ……………….. 209
References ………………………………………………………………………………………. 212
11 Applications of Coated Fabrics ………………………………………………………….. 213
Introduction ……………………………………………………………………………………. 213
11.1 Inflatable Structures …………………………………………………………………. 214
11.1.1 Inflatable Boats …………………………………………………………….. 214
11.1.2 Oil Booms……………………………………………………………………. 218
11.1.3 Inflatable Dams ……………………………………………………………. 219
11.1.4 Inflatable Buildings ……………………………………………………….. 220
11.1.5 Dunnage Bags ………………………………………………………………. 221
11.2 Non-Inflated Structures ……………………………………………………………. 222
11.2.1 Reservoir and Pond Liners ……………………………………………… 222
11.2.2 Flexible Storage Tanks …………………………………………………… 223
11.2.3 Supported Building Structures ………………………………………… 223
References ………………………………………………………………………………………. 224
12 Miscellaneous Applications of Textiles in Rubber …………………………………. 225
Introduction ……………………………………………………………………………………. 225
12.1 Hovercraft Skirts …………………………………………………………………….. 225
12.1.1 Types of Skirt ……………………………………………………………….. 226
12.2 Air Brake Chamber Diaphragms………………………………………………… 229
12.3 Snowmobile Tracks ………………………………………………………………….. 230
References ………………………………………………………………………………………. 231
Abbreviations and Acronyms………………………………………………………………….. 233
Glossary ……………………………………………………………………………………………… 234
Index ………………………………………………………………………………………………….. 239
Preface
Rubber and textiles have been used together, each working with the other to give improved performance in a very wide range of applications, since the earliest days of the rubber industry in the more developed areas of the world.
For many years, rubber companies of reasonable size, using textile reinforcement, would employ their own textile technologist working alongside the rubber technologists. Over the last third of the twentieth century, faced with global competition and the need to control and reduce total costs, this luxury has largely disappeared apart from the largest companies (particularly the tyre companies). Most organisations now rely on their textile suppliers to provide technical knowledge and expertise. As a result, the textile component for many applications is now considered in much the same way as the other raw materials, that is as an existing product, which only requires introducing into the manufacturing process, without any special knowledge or understanding, and is supplied against an agreed specification, which was probably drawn up by the textile manufacturer anyway. The aim of this current work is to provide a general background to and a basic awareness of the technology of textiles, to give the rubber technologists an improved understanding of the uses, processes and potential problems associated with the use of textiles in rubber products.
The most important and by far the largest use of textiles in rubber is in the tyre industry. This area is not covered in this book, as the field covers such a wide range that it would require a volume on its own. In addition, most tyre companies have their own textile specialists and have developed their own technologies, shrouded in the mysteries of ‘trade secrets’.
The first part of this volume covers the basic technology of the textile fibres and the processes used in preparing these ‘ready made’ raw materials for rubber reinforcement. Particular attention is given to various aspects of adhesion, adhesive treatments, the effects of rubber compounding and processing and the assessment of adhesion.
In the second half of the book, the major applications of textiles in rubber are described; the aim here is to illustrate the way that the textile component can be designed and engineered to obtain the optimum reinforcement and performance for each particular application. These descriptions are not intended to be definitive technological theses on the different applications. However, they indicate the balance of properties required and how these can be obtained in the textile component by selection of the fibres used, the physical form of the reinforcement and the processes and treatments required.
Over the years since the earliest days of Hancock, Goodyear and Macintosh, there have been many significant breakthroughs and developments, in both textile and rubber technologies. Originally, there were only cotton and natural rubber, now there are wide ranges of both synthetic rubbers and of man-made fibres. There have been great advances in the technologies of vulcanisation and of adhesive treatments; the service requirements have become more stringent and operating conditions more severe, but these issues have largely been overcome by improving expertise and knowledge.
However, over the last two decades, there has been relatively little advance in the general technologies of textiles or rubbers; most developments have been targeted either at cost containment or at very high performance (and consequently very high cost) applications, particularly aerospace, with only minor spin-offs for everyday terrestrial applications.
Where possible, the general content of the chapters has been kept as simple and practical as possible but where there is a more theoretical discussion of certain aspects, these have been separated into appendices, at the end of the relevant chapters. The general discussion can thus be read without the intrusion of the more theoretical aspects, but these are still available, if desired. A glossary of terms has been included to assist the reader.
I wish to thank all those at Rapra who have encouraged and assisted me in the preparation and publication of this book, in particular Clair Griffiths and Steve Barnfield, for their work in preparing the manuscript for publication.
David B. Wootton