Custom Molding of Thermoset Elastomers

Custom Molding of Thermoset Elastomers
اسم المؤلف
Bernie Stritzke
التاريخ
1 أكتوبر 2019
المشاهدات
التقييم
(لا توجد تقييمات)
Loading...

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

تحميل

يجب عليك التسجيل في الموقع لكي تتمكن من التحميل
تسجيل | تسجيل الدخول

التعليقات

اترك تعليقاً