Custom Molding of Thermoset Elastomers
A Comprehensive Approach to Materials, Mold Design, and Processing
Bernie Stritzke
Contents
Acknowledgment V
Preface VII
Contents IX
1 Introduction to Thermoset Elastomer Chemistry 1
1.1 Chemistry Overview . 1
1.2 Polymerization 3
1.3 Thermoplastic Polymers 4
1.4 Thermoset Polymers . 5
1.5 Organic and Silicone Elastomers 5
1.6 Cure Rates 7
1.7 Conclusion . 7
2 Compounding, Mixing and Equipment . 9
2.1 Introduction 9
2.2 Compounding 9
2.3 Mixing . 10
2.3.1 TSE Compound Batch Release Tests 14
2.4 Silicone 14
2.5 Conclusion . 15
3 Materials 17
3.1 Natural Rubber (NR) 17
3.2 Synthetic Polyisoprene (IR) . 18
3.3 Styrene-Butadiene (SBR) . 18
3.4 Polybutadiene (BR) 19
3.5 Butyl (IIR) . 19
3.6 Ethylene-Propylene-Diene (EPDM) 20
3.7 Nitrile (NBR) . 20
3.8 Polyacrylic (ACM) 21
3.9 Ethylene Acrylic (AEM) 21
3.10 Silicone (MQ, VMQ, and PMQ) . 21X Contents
3.11 Fluoroelastomer (FKM) 22
3.12 Polyurethane (AU and EU) . 23
3.13 Epichlorohydrin (CO and ECO) . 23
3.14 Conclusion . 23
4 Product Design . 25
4.1 Introduction 25
4.2 Material 25
4.2.1 ASTM Classification System for Elastomeric Materials . 27
4.3 Design . 28
4.3.1 Tolerances . 30
4.3.2 Material Shrinkage . 32
4.4 Conclusion . 33
5 Material Testing for TSE 35
5.1 Introduction 35
5.2 Physical and Chemical Properties Tests . 35
5.2.1 Tensile Testing . 36
5.2.2 Compression Set . 37
5.2.3 Durometer 37
5.3 Heat Aging . 38
5.3.1 Accelerated Aging 38
5.4 Rubber Property – Vulcanization Using Oscillating Disk Cure . 38
5.5 Fluid Resistance . 39
5.6 State-of-Cure . 40
5.7 Conclusion . 41
6 Polymer Flow 43
6.1 Viscosity . 43
6.2 Elasticity . 44
6.3 Plasticity . 45
6.4 Rheology . 45
6.4.1 Thermoplastic Fluid Properties . 46
6.4.2 TSE Fluid Properties 48
6.5 Shear Thinning . 49
6.6 Rotational Viscometers . 50
6.7 Oscillating Rheometers . 52
6.8 Conclusion . 53Contents XI
7 Molding Methods and Related Topics . 55
7.1 Introduction 55
7.2 Choosing a Process 55
7.3 Book Mold . 58
7.4 Bolt-In . 59
7.5 Shuttling . 59
7.5.1 Double Shuttle . 59
7.5.2 Single Plate Shuttle . 61
7.6 Rotary Molding . 62
7.7 Core Bar . 65
7.8 Mold Construction 66
7.8.1 Cavitation . 67
7.9 Article Removal/Ejection . 68
7.10 Mold Cavity Finish 68
7.11 Heaters 69
7.11.1 Heater Calculation 70
7.11.2 Running 72
7.11.3 Conclusion 72
7.12 Heat Transfer . 72
7.13 Insulation 74
7.14 Vacuum 74
7.15 Release Aids 78
7.15.1 Mold Lubes 78
7.15.2 Mold Plating . 78
7.16 Mold Cleaning 80
7.16.1 Plastic Media Blast . 80
7.16.2 Ultrasonic Cleaners . 81
7.16.3 Ice Blast . 81
7.17 Conclusion . 81
8 Compression Molding 83
8.1 Compression Presses . 83
8.2 Preps 84
8.3 Operator Influence and Automation . 85
8.4 Material Flow . 86
8.4.1 Trapped Air . 87
8.4.2 Molecular Orientation 87
8.5 Mold Construction 87XII Contents
8.5.1 Disk Springs . 88
8.5.2 Relative Cost . 89
8.6 Pressure 89
8.7 Backrind . 90
8.8 Mold Cleaning 90
8.9 Article Removal/Ejection . 90
8.10 Compression Mold and Die-Cut . 91
8.11 Dual Acting Spring Mechanism Compression Molding . 92
8.11.1 Prep Compensating Mechanism 95
8.11.2 Secondary Trim 96
8.12 Conclusion . 97
9 Transfer Molding . 99
9.1 Self-Contained Pot 99
9.2 Bottomless Pot Transfer 100
9.3 Transfer Press . 102
9.4 Flashless Transfer Molding 103
9.4.1 Split-Top Inserts 105
9.4.2 Vents . 106
9.4.3 Trapped Air . 107
9.4.4 Sprues/Gates . 107
9.4.5 Knit Lines . 108
9.4.6 Ring Gates 109
9.4.7 Mold Construction 109
9.4.8 Transfer Pressure . 109
9.5 Mold Cleaning 110
9.6 Wasteless Transfer . 111
9.6.1 Equalizing Platen . 113
9.7 Conclusion . 113
10 Injection Molding 115
10.1 Injection Unit . 116
10.1.1 First In – First Out (FIFO) . 118
10.1.2 Plunger Unit . 119
10.1.3 Injection Controls 119
10.1.4 Injection Location 120
10.1.5 Material Feed – Stripped 121
10.1.6 Material Feed – Stuffer 121Contents XIII
10.2 Materials . 121
10.3 Automation . 121
10.4 Mold Construction 124
10.5 Molding Defects . 124
10.5.1 Scorch 124
10.5.2 Cured Stock . 125
10.5.3 Adhesive Wash . 125
10.6 Injection Transfer . 125
10.7 Injection Compression . 125
10.8 Cold Runner Injection . 126
10.9 Valve-Gated Cold Runner . 127
10.10 Injection Pressure Considerations . 128
10.10.1 Pressure Compensator 129
10.11 Conclusion . 130
11 Liquid Silicone Rubber 131
11.1 The System . 132
11.2 The Static Mixer 132
11.3 Injection Unit . 133
11.4 Molds 135
11.5 Materials . 136
11.6 Special Applications . 137
11.6.1 Medical . 137
11.6.2 Food Contact 137
11.7 Color Or Other Additives . 137
11.8 Material Change . 137
11.9 Similarity to Plastic Injection Molding . 138
11.10 Two-Shot Molding . 138
11.11 Conclusion . 141
12 Secondary Operations and Additional Methods . 143
12.1 Post Curing . 143
12.2 Material Filtering 143
12.3 Flash 144
12.3.1 Cryogenic Deflash 145
12.4 Coatings . 146
12.4.1 Parylene Coating . 146
12.4.2 Plasma Treatment 147XIV Contents
12.4.3 Chlorination . 150
12.4.4 Oils 150
12.5 Adhesion . 151
12.5.1 Dipping . 151
12.5.2 Tumble Baskets 152
12.5.3 Chain-On-Edge 154
12.5.4 Rotary Table . 155
12.5.5 Other Application Methods 156
12.5.6 Self-Bonding Methods 156
12.5.7 Substrate Preparation . 157
12.6 Conclusion . 158
13 TSE Molding Processing 161
13.1 Prototype 161
13.1.1 Prototype Plan . 163
13.2 Production . 163
13.2.1 Cure Time/Temperature . 163
13.2.2 Sampling Phase 165
13.2.3 Qualification Phase . 165
13.2.4 Measurement Qualification 166
13.2.5 Continuous Improvement Phase 168
13.3 Troubleshooting . 169
13.4 Conclusion . 173
14 Manufacturing Process Planning . 175
Appendix 1 TSE Common Terms and Definitions 179
Subject Index 183
كلمة سر فك الضغط : books-world.net
The Unzip Password : books-world.net

عالم الكتب - Books World

Recent Posts

Magnetics, Dielectrics, and Wave Propagation with MATLAB Codes – Second Edition

Magnetics, Dielectrics, and Wave Propagation with MATLAB Codes - Second EditionCarmine VittoriaContentsPreface xiiPreface to the…

10 ساعات ago

SolidWorks Flow Simulation 2024 Black Book

SolidWorks Flow Simulation 2024 Black BookByGaurav VermaMatt Weber(CADCAMCAE Works)Edited byKristenTABLE OF CONTENTSPreface viiAbout Author ixChapter…

10 ساعات ago

Easy Guide to Health and Safety – Second Edition

Easy Guide to Health and Safety - Second EditionPhil Hughes MBE and Liz HughesContentsPreface xChapter…

11 ساعة ago

Finite Element Analysis – With Numeric and Symbolic MatLAB

Finite Element Analysis - With Numeric and Symbolic MatLABJohn E AkinRice University, USAContentsPreface vAbout the…

يومين ago