Radiation Technology for Polymers, Third Edition
By Jiri George Drobny
By Jiri George Drobny
Contents
Preface to First Edition………………………………………………………………………………xv
Preface to Second Edition……………………………………………………………………….xvii
Preface to Third Edition…………………………………………………………………………..xix
Author……………………………………………………………………………………………………..xxi
1. Introduction…………………………………………………………………………………………1
1.1 Basic Concepts………………………………………………………………………………2
References…………………………………………………………………………………………….4
2. Review of Elements of Radiation Science and Technology………………..5
2.1 UV and Visible Radiation……………………………………………………………..5
2.1.1 Light Emission from Mercury Gas Discharge……………………6
2.1.2 Light Emission from Microwave-Excited Discharge…………..9
2.1.3 Generation of Monochromatic UV Radiation…………………….9
2.1.4 UV Radiation from UV Light-Emitted Diode…………………..11
2.2 Ionizing Radiation Types……………………………………………………………13
2.2.1 Electron Beam Energy……………………………………………………..14
2.2.2 Gamma Rays……………………………………………………………………16
2.2.3 X-Rays………………………………………………………………………………18
2.2.4 Other Types of Ionizing Radiation……………………………………19
2.3 Comparison of UV and EB Processes………………………………………….20
References…………………………………………………………………………………………..22
3. Ultraviolet Curing Equipment (with Ruben Rivera)………………………..25
3.1 UV Lamps…………………………………………………………………………………..26
3.1.1 Medium-Pressure Mercury Lamps…………………………………..27
3.1.2 Electrodeless Mercury Lamps………………………………………….28
3.1.3 Low-Pressure Mercury Lamps…………………………………………30
3.1.4 High-Pressure Mercury Lamps………………………………………..30
3.1.5 Excimer Lamps………………………………………………………………..30
3.1.5.1 Barrier-Discharge-Driven Excimer Lamps………….31
3.1.5.2 Microwave-Driven Excimer Lamps…………………….33
3.1.6 Xenon Lamps……………………………………………………………………33
3.1.7 Light-Emitting Diode Lamps……………………………………………35
3.2 Lamp Housings…………………………………………………………………………..38
3.3 Power Supply and Controls…………………………………………………………40
3.3.1 Power Supply Systems……………………………………………………..40
3.3.2 Control Systems……………………………………………………………….42
3.4 UV-LED Curing Systems…………………………………………………………….43
3.4.1 Selected UV-LED Industrial Lamps/Systems…………………..45
References…………………………………………………………………………………………..49
4. Electron Beam Curing Equipment…………………………………………………….51
4.1 Particle Accelerators……………………………………………………………………54
4.1.1 Direct Accelerators…………………………………………………………..55
4.1.1.1 Electrostatic Generators………………………………………56
4.1.1.2 Resonant Transformers……………………………………….56
4.1.1.3 Iron Core Transformers………………………………………57
4.1.1.4 Insulating Core Transformers…………………………….57
4.1.1.5 Cockcroft-Walton Generators……………………………..58
4.1.1.6 Dynamitrons………………………………………………………58
4.1.2 Indirect Accelerators………………………………………………………..59
4.1.2.1 Traveling Wave Linacs………………………………………..60
4.1.2.2 Standing Wave Linacs…………………………………………61
4.1.2.3 Resonant Cavity Accelerators……………………………..61
4.1.2.4 Linear Induction Accelerators…………………………….61
4.1.2.5 Rhodotron Accelerators………………………………………62
4.1.3 Low-Energy Electron Accelerators……………………………………64
4.1.3.1 Single-Stage Scanned Beam Accelerator……………..66
4.1.3.2 Linear Cathode Electron Accelerators…………………67
4.1.3.3 Multifilament Linear Cathode Electron Accelerators………………………………………………………..70
4.1.4 Sealed Tube Lamp Accelerators………………………………………..74
References…………………………………………………………………………………………..77
5. UV Radiation Processes (with Ruben Rivera)…………………………………..81
5.1 Basic Concepts…………………………………………………………………………….81
5.2 Photoinitiators and Photosensitizers…………………………………………..83
5.2.1 Free Radical Photoinitiators……………………………………………..84
5.2.1.1 Type I Photoinitiators………………………………………….85
5.2.1.2 Type II Photoinitiators………………………………………..85
5.2.2 Free Radical Photoinitiators for UV-LED Curing……………..86
5.2.3 Cationic Photoinitiators……………………………………………………89
5.2.4 Anionic Photoinitiators…………………………………………………….89
5.2.5 Oxygen Inhibition of Cure……………………………………………….90
5.2.6 Initiation of UV Hybrid Curing………………………………………..91
5.3 Kinetics of Photoinitiated Reactions……………………………………………91
5.3.1 Kinetics of Free Radical Photopolymerization………………….91
5.3.2 Kinetics of Cationic Photopolymerization………………………..92
5.4 Chemical Systems in UV Processing…………………………………………..94
5.4.1 Free Radical-Initiated Systems…………………………………………94
5.4.1.1 Acrylate/Methacrylate Systems………………………….94
5.4.1.2 Styrene/Unsaturated Polyesters…………………………96
5.4.1.3 Vinyl Ether/Unsaturated Esters………………………….96
5.4.1.4 Thiol-Ene Systems………………………………………………96
5.4.1.5 Donor-Acceptor Complexes………………………………..97
5.4.2 Cationic Systems………………………………………………………………97
5.5 Photo-Cross-Linking of Polymers……………………………………………….99
References…………………………………………………………………………………………..99
6. Electron Beam Processes………………………………………………………………….103
6.1 Introduction………………………………………………………………………………103
6.2 Radiation Cross-Link Promoters……………………………………………….110
6.2.1 Indirect Cross-Link Promoters……………………………………….110
6.2.1.1 Halogenated Compounds…………………………………110
6.2.1.2 Nitrous Oxide……………………………………………………110
6.2.1.3 Sulfur Monochloride…………………………………………110
6.2.1.4 Bases…………………………………………………………………110
6.2.2 Direct Cross-Link Promoters………………………………………….111
6.2.2.1 Maleimides……………………………………………………….111
6.2.2.2 Thiols (Polymercaptans)……………………………………111
6.2.2.3 Acrylic and Allylic Compounds………………………..112
6.3 Retardants of Radiation Cross-Linking…………………………………….113
6.4 Electron Beam Processing of Plastics………………………………………..115
6.4.1 Polyolefins………………………………………………………………………115
6.4.1.1 Polyethylene……………………………………………………..115
6.4.1.2 Polypropylene…………………………………………………..117
6.4.2 Polystyrene…………………………………………………………………….117
6.4.3 Polyvinylchloride……………………………………………………………118
6.4.4 Polymethacrylates and Polyacrylates……………………………..118
6.4.5 Polyamides……………………………………………………………………..118
6.4.6 Polyesters……………………………………………………………………….118
6.4.7 Fluoroplastics…………………………………………………………………118
6.4.7.1 Polytetrafluoroethylene…………………………………….118
6.4.7.2 FEP……………………………………………………………………119
6.4.7.3 Other Fluoroplastics………………………………………….119
6.5 Electron Beam Processing of Elastomers…………………………………..120
6.5.1 Physical Properties of Radiation Cross-Linked Elastomers………………………………………………………………………123
6.5.2 Effects of Radiation on Individual Elastomers………………..124
6.5.2.1 Natural Rubber (NR) and Synthetic Polyisoprene……………………………………………………..124
6.5.2.2 Polybutadiene and Its Copolymers……………………127
6.5.2.3 Polyisobutylene and Its Copolymers…………………129
6.5.2.4 Ethylene-Propylene Copolymers and Terpolymers………………………………………………………131
6.5.2.5 Polychloroprene………………………………………………..132
6.5.2.6 Silicone Elastomers……………………………………………133
6.5.2.7 Fluorocarbon Elastomers…………………………………..134
6.5.2.8 Fluorosilicone Elastomers…………………………………135
6.5.2.9 Thermoplastic Elastomers…………………………………136
6.6 Electron Beam Processing of Liquid Systems……………………………138
6.7 Grafting and Other Polymer Modifications………………………………140
6.7.1 Grafting………………………………………………………………………….140
6.7.2 Other Polymer Modifications…………………………………………143
References…………………………………………………………………………………………144
7. Coating Methods Used in UV/EB Technology………………………………..153
7.1 Roll Coating………………………………………………………………………………153
7.1.1 Direct Roll Coating…………………………………………………………153
7.1.2 Reverse Roll Coating………………………………………………………154
7.2 Curtain Coating………………………………………………………………………..155
7.3 Spray Application……………………………………………………………………..157
7.3.1 Compressed Air Gun Spraying………………………………………157
7.3.2 Airless Gun Spraying……………………………………………………..157
7.4 Dip Coating………………………………………………………………………………158
7.5 Flow Coating…………………………………………………………………………….158
7.6 Spin Coating……………………………………………………………………………..158
7.7 Rod Coating………………………………………………………………………………158
7.8 Vacuum Coating……………………………………………………………………….159
References…………………………………………………………………………………………160
8. Applications of UV Radiation…………………………………………………………161
8.1 UV Curing of Coatings and Paints……………………………………………164
8.1.1 Functional and Decorative Coatings………………………………164
8.1.1.1 Coatings on Flat, Rigid Substrates…………………….164
8.1.1.2 UV Curing of Coatings on Flexible Substrates…………………………………………………………165
8.1.2 UV Curing of Lacquers, Varnishes, and Paints……………….166
8.1.3 Three-Dimensional Curing…………………………………………….166
8.1.4 UV Curing of Coatings and Inks on Cylindrical-Shaped Parts………………………………………………..167
8.1.5 UV Matting of Coatings………………………………………………….167
8.2 UV Curing of Adhesives……………………………………………………………167
8.2.1 Energy-Curable Laminating Adhesives………………………….168
8.2.2 Energy-Curable Pressure-Sensitive Adhesives……………….169
8.2.3 Energy-Curable Assembly Adhesives…………………………….172
8.3 UV-Cured Silicone Release Coatings…………………………………………173
8.4 Spot Curing……………………………………………………………………………….174
8.5 UV Curing in Printing and Graphic Arts………………………………….176
8.5.1 Screen Printing……………………………………………………………….177
8.5.2 Flexography……………………………………………………………………178
8.5.3 Letterpress and Offset Letterpress (Dry Offset)……………..180
8.5.4 Lithography…………………………………………………………………181
8.5.5 Rotogravure Printing………………………………………………….182
8.6 Rapid Prototyping…………………………………………………………………..185
8.7 UV Powder Coatings……………………………………………………………….185
8.7.1 The Chemistry of UV Curable Powders………………………186
8.7.2 Material and Substrate Preparation…………………………….187
8.7.3 Powder Coating Application……………………………………….188
8.7.4 Substrates Suitable for UV Powder Coating…………………190
8.7.5 Industrial Applications……………………………………………….191
8.8 Other Applications for UV Curing…………………………………………..191
8.8.1 Electronics…………………………………………………………………..191
8.8.2 Optical Components and Optoelectronic Applications……………………………………………………………….192
8.8.2.1 Optical Fibers…………………………………………………192
8.8.2.2 Other Optical and Optoelectronic Applications…………………………………………………..192
8.9 Automotive Applications…………………………………………………………193
8.9.1 OEM Applications……………………………………………………….193
8.9.2 Automotive Refinish Applications………………………………195
8.9.3 3D Printing………………………………………………………………….195
8.10 Production of Composites by UV Radiation…………………………….197
8.10.1 Dental Applications…………………………………………………….197
8.10.2 Other Composite Applications…………………………………….197
8.11 Hydrogels………………………………………………………………………………..198
References…………………………………………………………………………………………199
9. Applications of Electron Beam Radiation……………………………………….203
9.1 Electron Beam Process in Wire and Cable Technology…………….203
9.1.1 Equipment and Process……………………………………………….208
9.1.2 Materials……………………………………………………………………..212
9.1.3 Recent Developments and Trends……………………………….212
9.2 Electron Beam Process in Tire Technology………………………………213
9.3 Electron Beam Process in the Manufacture of Polyolefin Foams………………………………………………………………………………………217
9.3.1 Foam Expansion and Its Control…………………………………218
9.3.2 Manufacturing Processes……………………………………………219
9.3.3 Comparison of Chemical and Radiation Processes……..219
9.4 Electron Beam Process in the Production of Heat-Shrinkable Materials………………………………………………………………………………….221
9.4.1 Heat-Shrinkable Tubing………………………………………………222
9.4.2 Heat-Shrinkable Sheets and Films………………………………226
9.5 Electron Beam Process in Coatings, Adhesives, Paints, and Printing Inks……………………………………………………………………………227
9.5.1 Magnetic Media…………………………………………………………..228
9.5.2 Coatings………………………………………………………………………228
9.5.3 Printing and Graphic Arts…………………………………………..230
9.5.4 Adhesives……………………………………………………………………231
9.5.4.1 Pressure-Sensitive Adhesives (PSAs)……………231
9.5.4.2 Laminating Adhesives…………………………………232
9.5.5 Polymeric Fiber-Reinforced Composites……………………..233
9.5.6 Hydrogels……………………………………………………………………235
9.5.7 Production of Fluoroadditives…………………………………….235
9.6 Other Applications for Electron Beam Radiation…………………….236
References…………………………………………………………………………………………237
10. Dosimetry and Radiometry……………………………………………………………..243
10.1 EB Dosimetry…………………………………………………………………………..243
10.2 UV Radiometry……………………………………………………………………….249
10.2.1 Actinometers……………………………………………………………….250
10.2.2 Radiometers………………………………………………………………..250
10.2.2.1 Radiometers for Conventional Ultraviolet Lamps………………………………………………………….250
10.2.2.2 Radiometers for Ultraviolet Light-Emitting Diode Lamps……………………………………………….256
10.2.3 Radiochromic Films…………………………………………………….259
References…………………………………………………………………………………………261
11. Safety and Hygiene………………………………………………………………………….263
11.1 UV Equipment Health and Safety……………………………………………263
11.2 EB Equipment Health and Safety…………………………………………….265
11.3 Chemical Hazards…………………………………………………………………..266
References…………………………………………………………………………………………268
12. Recent Developments and Trends……………………………………………………269
12.1 Current Trends in Equipment and Chemistry…………………………270
12.1.1 UV/EB Equipment………………………………………………………271
12.1.2 Chemistry……………………………………………………………………271
12.2 Emerging Technologies and Applications……………………………….271
12.2.1 The Use of UV-LED in 3D Printing……………………………..271
12.2.2 Modification of Polymer Substrates Using Electron Beam-Induced Graft Copolymerization………………………272
12.2.3 Improving Surface Cure with UVC LED Lamps………….272
12.2.4 Applications for Sealed Tube EB Lamps………………………273
12.2.5 Advances in Energy Cure Inkjet Printing……………………273
12.2.6 Current State of and Trends in the UV-LED Technology………………………………………………………………….273
12.2.7 Advances in Energy-Curable Pressure-Sensitive Adhesives……………………………………………………………………274
12.2.8 EB Curing Technology in Web Package Printing……….275
12.2.9 Polymer Optics from UV-Curable Polymer Systems…..276
12.2.10 UV-LED for Automotive and Transportation Applications………………………………………………………………276
References…………………………………………………………………………………………277
Glossary………………………………………………………………………………………………….279
Appendix I: Bibliography……………………………………………………………………….293
Appendix II: Major Equipment Manufacturers…………………………………….297
Appendix III: Standard Radiation and Dosimetry Tests………………………301
Appendix IV: Major Suppliers of Raw Materials for UV/EB Curing……303
Appendix V: The Twelve Principles of Green Chemistry……………………..305
Index……………………………………………………………………………………………………….307
Preface to Second Edition……………………………………………………………………….xvii
Preface to Third Edition…………………………………………………………………………..xix
Author……………………………………………………………………………………………………..xxi
1. Introduction…………………………………………………………………………………………1
1.1 Basic Concepts………………………………………………………………………………2
References…………………………………………………………………………………………….4
2. Review of Elements of Radiation Science and Technology………………..5
2.1 UV and Visible Radiation……………………………………………………………..5
2.1.1 Light Emission from Mercury Gas Discharge……………………6
2.1.2 Light Emission from Microwave-Excited Discharge…………..9
2.1.3 Generation of Monochromatic UV Radiation…………………….9
2.1.4 UV Radiation from UV Light-Emitted Diode…………………..11
2.2 Ionizing Radiation Types……………………………………………………………13
2.2.1 Electron Beam Energy……………………………………………………..14
2.2.2 Gamma Rays……………………………………………………………………16
2.2.3 X-Rays………………………………………………………………………………18
2.2.4 Other Types of Ionizing Radiation……………………………………19
2.3 Comparison of UV and EB Processes………………………………………….20
References…………………………………………………………………………………………..22
3. Ultraviolet Curing Equipment (with Ruben Rivera)………………………..25
3.1 UV Lamps…………………………………………………………………………………..26
3.1.1 Medium-Pressure Mercury Lamps…………………………………..27
3.1.2 Electrodeless Mercury Lamps………………………………………….28
3.1.3 Low-Pressure Mercury Lamps…………………………………………30
3.1.4 High-Pressure Mercury Lamps………………………………………..30
3.1.5 Excimer Lamps………………………………………………………………..30
3.1.5.1 Barrier-Discharge-Driven Excimer Lamps………….31
3.1.5.2 Microwave-Driven Excimer Lamps…………………….33
3.1.6 Xenon Lamps……………………………………………………………………33
3.1.7 Light-Emitting Diode Lamps……………………………………………35
3.2 Lamp Housings…………………………………………………………………………..38
3.3 Power Supply and Controls…………………………………………………………40
3.3.1 Power Supply Systems……………………………………………………..40
3.3.2 Control Systems……………………………………………………………….42
3.4 UV-LED Curing Systems…………………………………………………………….43
3.4.1 Selected UV-LED Industrial Lamps/Systems…………………..45
References…………………………………………………………………………………………..49
4. Electron Beam Curing Equipment…………………………………………………….51
4.1 Particle Accelerators……………………………………………………………………54
4.1.1 Direct Accelerators…………………………………………………………..55
4.1.1.1 Electrostatic Generators………………………………………56
4.1.1.2 Resonant Transformers……………………………………….56
4.1.1.3 Iron Core Transformers………………………………………57
4.1.1.4 Insulating Core Transformers…………………………….57
4.1.1.5 Cockcroft-Walton Generators……………………………..58
4.1.1.6 Dynamitrons………………………………………………………58
4.1.2 Indirect Accelerators………………………………………………………..59
4.1.2.1 Traveling Wave Linacs………………………………………..60
4.1.2.2 Standing Wave Linacs…………………………………………61
4.1.2.3 Resonant Cavity Accelerators……………………………..61
4.1.2.4 Linear Induction Accelerators…………………………….61
4.1.2.5 Rhodotron Accelerators………………………………………62
4.1.3 Low-Energy Electron Accelerators……………………………………64
4.1.3.1 Single-Stage Scanned Beam Accelerator……………..66
4.1.3.2 Linear Cathode Electron Accelerators…………………67
4.1.3.3 Multifilament Linear Cathode Electron Accelerators………………………………………………………..70
4.1.4 Sealed Tube Lamp Accelerators………………………………………..74
References…………………………………………………………………………………………..77
5. UV Radiation Processes (with Ruben Rivera)…………………………………..81
5.1 Basic Concepts…………………………………………………………………………….81
5.2 Photoinitiators and Photosensitizers…………………………………………..83
5.2.1 Free Radical Photoinitiators……………………………………………..84
5.2.1.1 Type I Photoinitiators………………………………………….85
5.2.1.2 Type II Photoinitiators………………………………………..85
5.2.2 Free Radical Photoinitiators for UV-LED Curing……………..86
5.2.3 Cationic Photoinitiators……………………………………………………89
5.2.4 Anionic Photoinitiators…………………………………………………….89
5.2.5 Oxygen Inhibition of Cure……………………………………………….90
5.2.6 Initiation of UV Hybrid Curing………………………………………..91
5.3 Kinetics of Photoinitiated Reactions……………………………………………91
5.3.1 Kinetics of Free Radical Photopolymerization………………….91
5.3.2 Kinetics of Cationic Photopolymerization………………………..92
5.4 Chemical Systems in UV Processing…………………………………………..94
5.4.1 Free Radical-Initiated Systems…………………………………………94
5.4.1.1 Acrylate/Methacrylate Systems………………………….94
5.4.1.2 Styrene/Unsaturated Polyesters…………………………96
5.4.1.3 Vinyl Ether/Unsaturated Esters………………………….96
5.4.1.4 Thiol-Ene Systems………………………………………………96
5.4.1.5 Donor-Acceptor Complexes………………………………..97
5.4.2 Cationic Systems………………………………………………………………97
5.5 Photo-Cross-Linking of Polymers……………………………………………….99
References…………………………………………………………………………………………..99
6. Electron Beam Processes………………………………………………………………….103
6.1 Introduction………………………………………………………………………………103
6.2 Radiation Cross-Link Promoters……………………………………………….110
6.2.1 Indirect Cross-Link Promoters……………………………………….110
6.2.1.1 Halogenated Compounds…………………………………110
6.2.1.2 Nitrous Oxide……………………………………………………110
6.2.1.3 Sulfur Monochloride…………………………………………110
6.2.1.4 Bases…………………………………………………………………110
6.2.2 Direct Cross-Link Promoters………………………………………….111
6.2.2.1 Maleimides……………………………………………………….111
6.2.2.2 Thiols (Polymercaptans)……………………………………111
6.2.2.3 Acrylic and Allylic Compounds………………………..112
6.3 Retardants of Radiation Cross-Linking…………………………………….113
6.4 Electron Beam Processing of Plastics………………………………………..115
6.4.1 Polyolefins………………………………………………………………………115
6.4.1.1 Polyethylene……………………………………………………..115
6.4.1.2 Polypropylene…………………………………………………..117
6.4.2 Polystyrene…………………………………………………………………….117
6.4.3 Polyvinylchloride……………………………………………………………118
6.4.4 Polymethacrylates and Polyacrylates……………………………..118
6.4.5 Polyamides……………………………………………………………………..118
6.4.6 Polyesters……………………………………………………………………….118
6.4.7 Fluoroplastics…………………………………………………………………118
6.4.7.1 Polytetrafluoroethylene…………………………………….118
6.4.7.2 FEP……………………………………………………………………119
6.4.7.3 Other Fluoroplastics………………………………………….119
6.5 Electron Beam Processing of Elastomers…………………………………..120
6.5.1 Physical Properties of Radiation Cross-Linked Elastomers………………………………………………………………………123
6.5.2 Effects of Radiation on Individual Elastomers………………..124
6.5.2.1 Natural Rubber (NR) and Synthetic Polyisoprene……………………………………………………..124
6.5.2.2 Polybutadiene and Its Copolymers……………………127
6.5.2.3 Polyisobutylene and Its Copolymers…………………129
6.5.2.4 Ethylene-Propylene Copolymers and Terpolymers………………………………………………………131
6.5.2.5 Polychloroprene………………………………………………..132
6.5.2.6 Silicone Elastomers……………………………………………133
6.5.2.7 Fluorocarbon Elastomers…………………………………..134
6.5.2.8 Fluorosilicone Elastomers…………………………………135
6.5.2.9 Thermoplastic Elastomers…………………………………136
6.6 Electron Beam Processing of Liquid Systems……………………………138
6.7 Grafting and Other Polymer Modifications………………………………140
6.7.1 Grafting………………………………………………………………………….140
6.7.2 Other Polymer Modifications…………………………………………143
References…………………………………………………………………………………………144
7. Coating Methods Used in UV/EB Technology………………………………..153
7.1 Roll Coating………………………………………………………………………………153
7.1.1 Direct Roll Coating…………………………………………………………153
7.1.2 Reverse Roll Coating………………………………………………………154
7.2 Curtain Coating………………………………………………………………………..155
7.3 Spray Application……………………………………………………………………..157
7.3.1 Compressed Air Gun Spraying………………………………………157
7.3.2 Airless Gun Spraying……………………………………………………..157
7.4 Dip Coating………………………………………………………………………………158
7.5 Flow Coating…………………………………………………………………………….158
7.6 Spin Coating……………………………………………………………………………..158
7.7 Rod Coating………………………………………………………………………………158
7.8 Vacuum Coating……………………………………………………………………….159
References…………………………………………………………………………………………160
8. Applications of UV Radiation…………………………………………………………161
8.1 UV Curing of Coatings and Paints……………………………………………164
8.1.1 Functional and Decorative Coatings………………………………164
8.1.1.1 Coatings on Flat, Rigid Substrates…………………….164
8.1.1.2 UV Curing of Coatings on Flexible Substrates…………………………………………………………165
8.1.2 UV Curing of Lacquers, Varnishes, and Paints……………….166
8.1.3 Three-Dimensional Curing…………………………………………….166
8.1.4 UV Curing of Coatings and Inks on Cylindrical-Shaped Parts………………………………………………..167
8.1.5 UV Matting of Coatings………………………………………………….167
8.2 UV Curing of Adhesives……………………………………………………………167
8.2.1 Energy-Curable Laminating Adhesives………………………….168
8.2.2 Energy-Curable Pressure-Sensitive Adhesives……………….169
8.2.3 Energy-Curable Assembly Adhesives…………………………….172
8.3 UV-Cured Silicone Release Coatings…………………………………………173
8.4 Spot Curing……………………………………………………………………………….174
8.5 UV Curing in Printing and Graphic Arts………………………………….176
8.5.1 Screen Printing……………………………………………………………….177
8.5.2 Flexography……………………………………………………………………178
8.5.3 Letterpress and Offset Letterpress (Dry Offset)……………..180
8.5.4 Lithography…………………………………………………………………181
8.5.5 Rotogravure Printing………………………………………………….182
8.6 Rapid Prototyping…………………………………………………………………..185
8.7 UV Powder Coatings……………………………………………………………….185
8.7.1 The Chemistry of UV Curable Powders………………………186
8.7.2 Material and Substrate Preparation…………………………….187
8.7.3 Powder Coating Application……………………………………….188
8.7.4 Substrates Suitable for UV Powder Coating…………………190
8.7.5 Industrial Applications……………………………………………….191
8.8 Other Applications for UV Curing…………………………………………..191
8.8.1 Electronics…………………………………………………………………..191
8.8.2 Optical Components and Optoelectronic Applications……………………………………………………………….192
8.8.2.1 Optical Fibers…………………………………………………192
8.8.2.2 Other Optical and Optoelectronic Applications…………………………………………………..192
8.9 Automotive Applications…………………………………………………………193
8.9.1 OEM Applications……………………………………………………….193
8.9.2 Automotive Refinish Applications………………………………195
8.9.3 3D Printing………………………………………………………………….195
8.10 Production of Composites by UV Radiation…………………………….197
8.10.1 Dental Applications…………………………………………………….197
8.10.2 Other Composite Applications…………………………………….197
8.11 Hydrogels………………………………………………………………………………..198
References…………………………………………………………………………………………199
9. Applications of Electron Beam Radiation……………………………………….203
9.1 Electron Beam Process in Wire and Cable Technology…………….203
9.1.1 Equipment and Process……………………………………………….208
9.1.2 Materials……………………………………………………………………..212
9.1.3 Recent Developments and Trends……………………………….212
9.2 Electron Beam Process in Tire Technology………………………………213
9.3 Electron Beam Process in the Manufacture of Polyolefin Foams………………………………………………………………………………………217
9.3.1 Foam Expansion and Its Control…………………………………218
9.3.2 Manufacturing Processes……………………………………………219
9.3.3 Comparison of Chemical and Radiation Processes……..219
9.4 Electron Beam Process in the Production of Heat-Shrinkable Materials………………………………………………………………………………….221
9.4.1 Heat-Shrinkable Tubing………………………………………………222
9.4.2 Heat-Shrinkable Sheets and Films………………………………226
9.5 Electron Beam Process in Coatings, Adhesives, Paints, and Printing Inks……………………………………………………………………………227
9.5.1 Magnetic Media…………………………………………………………..228
9.5.2 Coatings………………………………………………………………………228
9.5.3 Printing and Graphic Arts…………………………………………..230
9.5.4 Adhesives……………………………………………………………………231
9.5.4.1 Pressure-Sensitive Adhesives (PSAs)……………231
9.5.4.2 Laminating Adhesives…………………………………232
9.5.5 Polymeric Fiber-Reinforced Composites……………………..233
9.5.6 Hydrogels……………………………………………………………………235
9.5.7 Production of Fluoroadditives…………………………………….235
9.6 Other Applications for Electron Beam Radiation…………………….236
References…………………………………………………………………………………………237
10. Dosimetry and Radiometry……………………………………………………………..243
10.1 EB Dosimetry…………………………………………………………………………..243
10.2 UV Radiometry……………………………………………………………………….249
10.2.1 Actinometers……………………………………………………………….250
10.2.2 Radiometers………………………………………………………………..250
10.2.2.1 Radiometers for Conventional Ultraviolet Lamps………………………………………………………….250
10.2.2.2 Radiometers for Ultraviolet Light-Emitting Diode Lamps……………………………………………….256
10.2.3 Radiochromic Films…………………………………………………….259
References…………………………………………………………………………………………261
11. Safety and Hygiene………………………………………………………………………….263
11.1 UV Equipment Health and Safety……………………………………………263
11.2 EB Equipment Health and Safety…………………………………………….265
11.3 Chemical Hazards…………………………………………………………………..266
References…………………………………………………………………………………………268
12. Recent Developments and Trends……………………………………………………269
12.1 Current Trends in Equipment and Chemistry…………………………270
12.1.1 UV/EB Equipment………………………………………………………271
12.1.2 Chemistry……………………………………………………………………271
12.2 Emerging Technologies and Applications……………………………….271
12.2.1 The Use of UV-LED in 3D Printing……………………………..271
12.2.2 Modification of Polymer Substrates Using Electron Beam-Induced Graft Copolymerization………………………272
12.2.3 Improving Surface Cure with UVC LED Lamps………….272
12.2.4 Applications for Sealed Tube EB Lamps………………………273
12.2.5 Advances in Energy Cure Inkjet Printing……………………273
12.2.6 Current State of and Trends in the UV-LED Technology………………………………………………………………….273
12.2.7 Advances in Energy-Curable Pressure-Sensitive Adhesives……………………………………………………………………274
12.2.8 EB Curing Technology in Web Package Printing……….275
12.2.9 Polymer Optics from UV-Curable Polymer Systems…..276
12.2.10 UV-LED for Automotive and Transportation Applications………………………………………………………………276
References…………………………………………………………………………………………277
Glossary………………………………………………………………………………………………….279
Appendix I: Bibliography……………………………………………………………………….293
Appendix II: Major Equipment Manufacturers…………………………………….297
Appendix III: Standard Radiation and Dosimetry Tests………………………301
Appendix IV: Major Suppliers of Raw Materials for UV/EB Curing……303
Appendix V: The Twelve Principles of Green Chemistry……………………..305
Index……………………………………………………………………………………………………….307