Report No. 97 FOAMED PLASTICS by DONALD C. THOMAS November 1975 A private report by the PROCESS ECONOMICS PROGRAM STANFORD RESEARCH INSTITUTE MENLO PARK, CALIFORNIA
CONTENTS 1 INTRODUCTION 1 2 SUMMARY... 3 Polyvinyl Chloride Foam Profiles by Extrusion... 6 Phenolic Foam Slab Stock Manufacture... 7 Polystyrene Foam Articles by Low-Pressure Molding... 7 Polyethylene Foam Sheet by Extrusion... 8 3 INDUSTRY STATUS... 9 End Use Pattern... 10 Structural Foam... 10 Utility Foam... 12 Insulation... 13 Safety and Health Hazards... 14 Toxic Gas Emission During Processing... 15 Smoke and Toxic Gas Evolution from Burning Plastics 15 Flammability... 15 Equipment for Structural Foam... 16 4 PLASTIC FOAM TYPES AND MANUFACTURING TECHNIQUES AND LICENSORS, 19 Types of Plastic Foam... Open-Cell Foams... Closed-Cell Foams... Sandwich Foams... Reticulated Foams... Techniques and Licensors... Extrusion Technique... Molding Technique Union Carbide Structural Foam Process USM Structural Foam Process Kraus-Maffei Structural Foam Process Mitsubishi MJC Structural Foam Process TAF Structural Foam Process... ICI Sandwich Process... Short-Shot Process Foam-in-Place Technique. Improving Fire Retardancy........ 19... 19... 19... 20... 21... 21... 21... 27... 30... 32... 33... 33... 34... 35... 35... 36... 38 5 BLOWING AGENTS, 41 Gas Injection. Vaporization of a Volatile Material 41 42 vii
5 (Continued) Evolution of Gas or Vapor on Decomposition of a Chemical Chemical Agents... Azodicarbonamide'... Azobisisobutyronitrile N,N'-Dinitrosopentamethylenetetramine N,N'-Dimethyl-N,N'-dinitrosoterephthalamide... Sodium Bicarbonate... Foamable Resins... Nucleating Agents Markets in the United States 46 57 59 59 60 61 61 62 64 66 6 POLYETHYLENE FOAM.,. 67 General Features Applications Review of Processes Extrusion Molding. Cross-Linking. Foamable Polyethylene Open-Cell Polyethylene Fire Retardancy. Process Description Process Discussion. Cost Estimates. Opportunities for Improvement... 7 POLYVINYL CHLORIDE FOAM 93 Applications... Review of Processes.. Foaming of Melted Resin. Foaming of Plastisol... Process Description. Materials Receipt Section Processing Section... Product Removal and Shipment Section... Process Discussion... Cost Estimates... Capital Costs... Production Costs'... Summary and Analysis of Costs... 67 69 69 71 71 76 79 79 84 86 89 89 90 93 97 97 100 105 107 108 109 111 111 111 112 112 8 POLYSTYRENEFOAM... General Characteristics.. Applications... Review of Processes Expandable Polystryrene... Molding of Resin... Extrusion... 121 121 124 126 126 128 128. Vlll
8 (Continued) Fire Retardants... 136 Compositions for Special Properties... 136 Scrap Utilization... 136 Process Description... 139 Process Discussion... 142 Cost Estimates... 145 Capital Costs 145 Production Costs'... 146 Opportunities for Cost Improvement... 146 9 PHENOLIC FOAM... :... 151 General Features... 151 Applications... 154 Review of Processes... 158 Slabs... 162 Foam-in-Place... 163 Sandwich Panels... 163 Spraying... 164 Catalysts... 164 Surface-Active Agents.. 165 Formulations... 166 Insulation... 166 Reduced Combustibility.. 166 Composites... 167 Open-Cell Foams... 167 Process Description... 168 Process Discussion... 172 Cost Estimates... 172 10 OTHER PLASTIC FOAMS... 175 Polypropylene Foams... 175 Urea-Formaldehyde Foams.. 176 Epoxy Foams... 177 Ionomer Foams... 177 Cellulose Acetate Foams.. 178 Polycarbonate Foams... 179 Nylon Foams... 179 Acrylonitrile-Butadiene-Styrene Foams 179 Polyphenylene Oxide Foams... 180 Polybutylene Terephthalate Foams 180 Polysulfone Foams... 181 Polyimide Foams... 181 APPENDIX A DESIGN AND COST BASIS 185 APPENDIX B TRADE NAMES OF FOAMED PLASTICS 189 (APPENDIX C has been deleted) ix
APPENDIX D APPLICATIONS OF PLASTIC FOAM... 195 APPENDIX E SUMMARY OF RESINS 199 CITED REFERENCES... 203 PATENT REFERENCES BY COMPANY. 227 X
ILLUSTRATIONS 4.1 The Celuka Process... 26 4.2 The Effect of Cooling on Molded Foams... 29 4.3 Low-Pressure Molding.. 31 4.4 Cost of Molding Machines 37 5.1 Effect of Blowing Agent Concentration on Foam Density 43 5.2 Cost of Blowing Gas from Various Blowing Agents... 44 5.3 Decomposition Temperature and Gas Evolution Profile of Some Chemical Blowing Agents... 47 5.4 Gas Evolution from Sodium Bicarbonate... 63 6.1 Increased Temperature Range by Cross-Linking... 77 6.2 Cross-Linked Polyethylene Foam by a Four-Step Process 80 6.3 Foamed Polyethylene Film by Extrusion... 235 7.1 Elastomer' Process... 103 7.2 Plastisol Foam-Fabric Laminate Finishing Line... 104 7.3 by Extrusion... 237 7.4 by Extrusion Effect of Operating Level and Plant Capacity on Production Cost... 118 7.5 by Extrusion Effect of Operating Level and Plant Capacity on Desirable Sales Price.. 119 7.6 Sensitivity of Desirable Sales Price of Profile to Resin Cost... 120 8.1 Polystyrene Foam by Extrusion... 135 8.2 Low-Pressure Foam Molding of Polystyrene... 237 9.1 Phenolic Foam Slab Stock Production Process... 241 xi
TABLES 2.1 3.1 3.2 3.3 3.4 4.1 4.2 5.1 5.2 5.3 5.4 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 Foamed Plastics Manufacture Summary of Economics. Structural Foam Recent and Projected End-Use Patterns in the United States. Structural Foam Recent and Projected Demand for Resin in the United States. Manufactureres of Machinery for Making Structural Foam Manufacturers of Foam Extrusion Systems Marketed in the United States. Some Foamed Plastics Processes Available for License. Other Sources of Plastics Foaming Technology. Properties and Costs of Volatile Blowing Agents. Commercial Chemical Blowing Agents... Other Blowing Agents... Nucleating Agents for Plastic Foams... Properties of Polyethylene Foam... Properties of Some Commercial Polyethylene Foam. Polyethylene Foam by Extrusion Polyethylene Foam by Molding Polyethylene Foam by Radiation Cross-Linking Polyethylene Foam: Expandable Resin Polyethylene Foam: Open-Cell Polyethylene Foam: Fire Retardant Foamed Polyethylene Film by Extrusion Major Process Equipment and Utilities Summary., 5 11 11 17 18 22 24 45 50 54 65 68 70 72 74 78 81 83 85 88 xiii
TABLES 6.10 6.11 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 8.1 8.2 8.3 8.4 Polystyrene Foam Extrusion 8.5 8.6 8.7 8.8 Foamed Polyethylene Film by Extrusion Total Capital Investment. Foamed Polyethylene Film by Extrusion Production Costs... Properties of Polyvinyl Chloride... Polyvinyl Chloride Foam by Extrusion Patent Summary... Polyvinyl Chloride Foam by Molding Patent Summary... Design Bases... Major Process Equipment and Utilities Summary... Total Capital Investment. Capital Investment by Process Section... Production Costs... Production Costs by Process Section... Characteristics of Polystyrene Foams... Typical Physical Properties of Polystyrene Foams... Polystyrene Foam Molding Patent Summary... Polystyrene Foam: Fire Retardant Compositions for Special Polystyrene Foam Properties Low-Pressure Foam Molding of Polystyrene Major Process Equipment and Utilities Summary Low-Pressure Foam Molding of Polystyrene Total Capital Investment. 91 92 94 98 101 106 110 114 115 116 117 122 123 129 133 137 138 141 148 xiv
TABLES 8.9 Low-Pressure Foam Molding of Polystyrene Production Costs. 9.1 Features of Phenolic Foam 9.2 9.3 9.4 9.5 9.6 9.7 9.8 10.1 Typical Flammability Properties of Phenolic Foam from Resole. Physical Properties of Phenolic Foam and Precursor Materials Phenolic Foam Fire-Retardant and Self-Extinguishing Formulations for the Phenolic Foam Slab Stock Process. Phenolic Foam Slab Stock Process Major Process Equipment. Phenolic Foam Slab Stock Process Total Capital Investment. Phenolic Foam Slab Stock Process Production Costs. Other Plastic Foams B.l Commercial Foamed Plastics D.l Reported Applications of Foamed Plastics... E.l Summary of Resins... 149 153 155 156 159 169 171 173 174 182 190 196 200 xv