Polymer Products: Design, Materials and Processing

357 Pages·1986·7.848 MB·English

by  David H. Morton-Jones, John W. Ellis (auth.)

Polymer
Products
DESIGN, MATERIALS
AND PROCESSING
Polymer
Products
DESIGN, MATERIALS
AND PROCESSING
David H. Morton-Jones
Dowty Research Fellow
University of Lancaster
John W Ellis
Formerly Senior Lecturer in Plastics Engineering
Singapore Polytechnic
LONDON NEW YORK
CHAPMAN AND HALL
First published in 1986 by
Chapman and Hall Ltd
11 New Fetter Lane, London EC4P 4EE
Published in the USA by
Chapman and Hall
29 West 35th Street, New York NY 10001
© 1986 D. H. Morton-Jones and J W Ellis
Softcover reprint of the hardcover 1s t edition 1986
All rights reserved. No part of this book may be
reprinted, or reproduced or utilized in any form or by
any electronic, mechanical or other means, now know
or hereafter invented, including photocopying and
recording, or in any information storage and retrieval
system, without permission in writing from the
publisher.
British Library Cataloguing in Publication Data
Morton-Jones, D. H.
Polymer products: design, materials and processing.
1. Polymers and polymerization
1. Title II. Ellis, J W
620.1'92 TA455.P58
Library of Congress Cataloging in Publication Data
Morton-Jones, D. H (David H), 1931-
Polymer products
Bi,bliography: p.
Includes index.
1. Polymers and polymerization. 1. Ellis,
J W Oohn W), 1941- II. Title.
TA455.P58M64 1986 668.9 85-22420
ISBN-13: 978-94-010-8320-1 e-ISBN-13: 978-94-009-4101-4
DOl: 10 .1007/978-94-009-410 1-4
This book is dedicated to Roy Smith,
our mentor in the original
Case-studies project
CONTENTS
Preface xiii
Acknowledgements xiv
List of Participating Companies xv
PST 1: Injection Moulding and its Materials
1.1 Injection moulding 1
1.2 Amorphous and crystalline polymers 5
1.3 Polymers in the rubber state 7
1.4 Environmental stress cracking 9
1.5 Creep in polymers 9
2 Optimizing Injection Moulding Conditions 13
2.1 Introduction 13
2.2 Support bracket 13
2.3 Film spool end 19
2.4 Comment on importance of process 24
2.5 Control features in injection moulding 24
2.6 The case for the programmed machine 32
3 Some Examples of Polymer Selection 33
3.1 Combination nozzle for Electrolux cleaner 33
3.2 Impellor for Flymo hover mower 36
3.3 Flymo mower hood 38
3.4 Motor housing in vacuum cleaner 39
3.5 Moulding conditions 40
3.6 Polymer science aspects: polymers in the rubber state 41
4 Plastics Gears 42
4.1 Introduction 42
4.2 The GEC reduction gear box 43
4.3 Why plastics gears? 44
4.4 Methods for making plastics gears 44
4.5 Design of moulded gears 45
4.6 Materials 56
4.7 Design development of office copier gearbox 59
4.8 Injection moulding of gears 63
4.9 References 64
Contents
5 Acetal Clips for Roof Tiles 65
5.1 Introduction 65
5.2 The mark 9 clip 65
5.3 Loading calculations 67
5.4 Production and quality control 69
6 Acetal Spring for Selector Switch 70
6.1 Introduction 70
6.2 Development of the acetal spring 70
6.3 Evaluation and testing 74
6.4 Polymer and processing 75
6.5 Comment on design and polymer properties 77
7 PST 2: Foam Cored Mouldings 78
7.1 Structural foam 78
7.2 Comparison of the sandwich moulding and structural
foam processes 89
7.3 The sandwich moulding process 90
7.4 Relative merits of compact moulding 90
8 Structural Foam Trolley Base 94
8.1 Introduction 94
8.2 Design brief 95
8.3 Material and manufacturing process selection 96
8.4 Design procedure 97
8.5 The moulding process 99
8.6 References 101
9 Washing Machine Tank in Glass-coupled Polypropylene
Structural Foam 102
9.1 Introduction 102
9.2 Background 103
9.3 Operating conditions of the tank 103
9.4 Materials and process selection 103
9.5 Design features 106
9.6 The mould 108
9.7 The moulding machine 108
9.8 Processing conditions 108
9.9 Secondary operation 109
9.10 Testing 109
10 Sandwich Moulded TV Screen Frame 111
10. 1 Synopsis 111
10.2 Design of the moulded TV front 111
10.3 Production details 114
10.4 Tests of finished product 116
10.5 Some other aspects of SM 116
10.6 Sandwich moulded toilet cisterns 117
10.7 UK involvement in SM 118
viii
Contents
11 PST 3: Polyurethanes 119
11.1 Introduction 119
11.2 Basic reactions 120
11.3 Materials 122
11.4 Relationships between structure and properties 125
11.5 Polyurethane foam 125
12 Reinforced Reaction Injection Moulding (RRIM) 127
12.1 Introduction 127
12.2 Polyurethane systems 127
12.3 Development of short glass-fibre reinforcement 127
12.4 RRIM development 129
12.5 The RRIM process 130
13 Polyurethane Shoe Soles 133
13.1 Introduction 133
13.2 Shoe manufacture - historical 133
13.3 Development of the PU sole 135
13.4 Polyurethane materials 138
13.5 PU shoe soling 138
13.6 Manufacture 141
13.7 Product testing 143
13.8 Design considerations 145
13.9 References 146
14 Printed Gaskets in Hydraulic Control Equipment 147
14.1 Background 147
14.2 The hydraulic control valve 147
14.3 The printed gasket 147
14.4 Polyurethane seal 147
14.5 Selection of materials 150
14.6 Production of the printed gasket 150
14.7 Testing and quality control 154
14.8 Failure in printed gaskets 155
14.9 Development of new specifications 155
14.10 Future Developments 158
IS PST 4: Glass-reinforced Plastics (GRP) 159
15.1 Introduction 159
15.2 Reinforcing fibres 160
15.3 Unsaturated polyester resins 161
15.4 The hand lay-up process 162
15.5 Sheet moulding compound (SMC) 164
15.6 Disadvantage of SMC Moulding Compared with
Hand Lay-up 166
15.7 Stiffness of materials (with reference to GRP) 167
15.8 Plastics vehicle bodies 169
ix
Contents
16 GRP-Clad Lorry Cab 173
16.1 General description 173
16.2 Design considerations 173
16.3 Materials selection 178
16.4 Production details 179
16.5 Testing 182
16.6 Summary of costs 182
16.7 References 183
17 High Speed Train Cab 184
17.1 Introduction 184
17.2 Design considerations 184
17.3 Materials 191
17.4 Production details 192
18 DMC Vehicle Headlamps 196
18.1 Introduction 196
18.2 Historical 197
18.3 Material selection 198
18.4 Some design aspects 200
18.5 Quality and performance aspects 203
18.6 Technical appendix {Lucas} 204
18.7 Manufacture 206
18.8 The test programme 209
19 'Fiberlam' Aircraft Flooring 211
19.1 General description of 'Fiberlam' 211
19.2 Materials 211
19.3 Manufacturing aspects 214
19.4 Some product features 215
19.5 Testing 217
19.6 History of sandwich structures in aircraft flooring 217
19.7 References 220
20 PST 5: Rubbers 221
20.1 Natural and synthetic rubbers 221
20.2 Polychloroprene rubber 222
20.3 Vulcanization 223
21 Rubber-Steel Conveyor Belt 226
21.1 Introduction 226
21.2 Background 226
21.3 The development of steel cord belting 227
21.4 Development of the Selby conveyor 233
21.5 Manufacture 237
21.6 Product testing 244
21. 7 Installation 250
21.8 References 251
x
Contents
22 The Blow Moulding Process 252
22.1 Introduction 252
22.2 Blow moulding of large containers 253
22.3 Injection blow moulding 254
23 The Acitainer Blow Moulded Acid Container 255
23.1 Introduction 256
23.2 Design considerations 258
23.3 Material selection 263
23.4 Production details 267
23.5 References 269
24 Chemical Effluent Pipe in HOPE 270
24.1 Introduction 270
24.2 Effluents 270
24.3 Selection of materials 270
24.4 Design factors 275
24.5 Manufacture and assembly 276
24.6 Quality control and testing 281
24.7 Pressure pipe - pressure rating calculation 284
24.8 Static loads in buried pipe 287
24.9 Appendix: Crack Propagation 293
25 Failure of a Polypropylene Vessel 295
25.1 Introduction 295
25.2 The plant 295
25.3 The failure incident 297
25.4 Examination of fractured pipe 298
25.5 Investigation 298
25.6 Fracture calculations 299
25.7 Bubble collapse 303
25.8 Conclusion 304
25.9 Remedial action 304
26 Heat Shrinkable Terminations for Power Cables 305
26.1 Introduction 305
26.2 Heat-shrinkable plastics 306
26.3 Power cables 308
26.4 Termination by tradi tiona I methods 309
26.5 Application of heat-shrinkable plastks in MV 310
26.6 Heat-shrinkable plastics in high voltage applications 310
26.7 Stress grading 311
26.8 Non-tracking outer insulation 317
26.9 High voltage non-track material (HVTM) 330
26.10 Sealant 334
26.11 The development programme 334
26.12 References 335
Index 337
xi