PROCESS ECONOMICS PROGRAM

SRI INTERNATIONAL Menlo Park, California Abstract 94025

PROCESS ECONOMICS PROGRAM REPORT NO. 165

CARBON FIBERS

(September 1983)

Carbon fiber is a lightweight, flexible, high strength, high tensile modulus material produced from polyacrylonitrile (PAN), pitch, or rayon by a series of heating steps. It Is used as a material of construction for aircraft, spaceships, sporting goods, and industrial products where weight savings and performance are of primary considera- tion. The demand for carbon fiber is still small (1,440 metric tons in 1982) but is growing very rapidly, averaging about 35%/yr In the last 10 years.

This report reviews the technology for making carbon fiber and pre- sents cost estimates for making the following representative products:

l Mesophase pitch-based continuous yarn

l PAR-based continuous yarn

l Rayon-based fabric

l Rayon-based felt.

PEP'82 JJLM - Report No. 165 a CARBON FIBERS

by JAMES J. L. MA

I 0 I September 1983 0 - a A private report by the m PROCESS ECONOMICS PROGRAM 0 Menlo Park, California 94025 For detailed marketing data and information, the reader is referred to one of the SRI programs specializing in marketing research. The CHEMICAL ECONOMICS HANDBOOK Program covers most major chemicals and chemical products produced in the United States and the WORLD PETROCHRMICALS Program covers major hydrocarbons and their derivatives on a worldwide basis. In addition, the SRI DIRECTORY OF CHEMICAL PRODUCERS services provide detailed lists of chemical producers by company, prod- uct, and plant for the United States and Western Europe.

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CONTENTS

1 INTRODUCTION. , . , ...... 1

2 SUMMARY ...... 3 Commercial Aspects...... 3 Economic Aspects...... 5 Technical Aspects ...... 8

3 INDUSTRY STATUS ...... 11 Precursors...... 11 Plant Capacities...... 11 Consumption ...... 13 Product Properties...... 16 Product Classifications ...... 20 Product Forms and Prices...... 21 Product Applications...... 25 Competitive Materials ...... 27

4 CARBON FIBER FROM PITCH ...... 29 Chemistry ...... 29 Pitch Properties...... 32 PVC-Derived Pitch ...... 32 Coal Tar and Petroleum Pitches...... 34 Mesophase Pitch ...... 36 Review of Processes ...... 38 Union Carbide Process ...... 39 Exxon Process ...... 41 Other U.S. Processes...... i ...... 44 Kureha Processes...... 44 Other Developments in Japan ...... 46 Developments in Europe...... 47 Melt Spinning ...... 47 Process Description ...... 49 l Pitch Preparation and Spinning...... 49 Thermosetting ...... 52 Carbonizing ...... 52 Graphitizing...... 53 Surface Treating...... 53 Process Discussion...... 57 Cost Estimates...... 59 Capital Costs ...... 59 Production Costs...... 60

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5 CARBON FIBER FROM POLYACRYLONITRILE ...... 67 Chemistry ...... 67 Review of Processes ...... 69 Patents ...... 69 Precursor Forms ...... 72 Off-Gas Treatment ...... 73 Factors Affecting Product Properties, ...... 75 Length Change During Stabilization...... 75 Carbonization Temperature ...... 75 Precursor Spinning, ...... 78 Fiber Diameter...... 78 Test Specimen Gage Length ...... 78 Density ...... 81 Process Description ...... 81 Process Discussion...... 87 CostEstimates ...... 88 Capital Costs ...... 88 Production Costs...... 88

6 CARBON FIBERFROMRAYON ...... 95 Chemistry ...... 95 Review of Processes ...... 98 Patents ...... 98 Precursor Forms ...... 100 Process Description ...... 103 Carbon Fabric from Rayon...... 103 Carbon Felt from Rayon...... 106 Process DiscussionW ...... 112 Carbon Fabric from Rayon...... 112 Carbon Felt from Rayon...... 112 Cost Estimates...... 113 Capital Costs--Carbon Fabric from Rayon ...... 113 Capital Costs--Carbon Felt from Rayon ...... 114 Production Costs--Carbon Fabric from Rayon...... 114 Production Costs--Carbon Felt from Rayon...... 115

7 CARBON FIBER FROM OTHER PRECURSORS...... 123

8 POSTCARBONIEATION SURFACE TREATMENTS...... 125

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APPENDIXA DESIGN AND COST BASIS . . , . . , . . , . . . . . 127

APPENDIX B PRODUCT SAFETY FOR CARBON FIBER . . . , . . . . . 131

CITED REFERENCES...... 195

PATENT REFERENCES...... 213

V ILLUSTRATIONS

3.1 Network of Carbon Fiber, Prepreg, and Composite Producers...... 14 4.1 Schematic Diagram of the Orientating Process During the Spinning of Mesophase Pitch , . : ...... 30 4.2 Molecular Structure Changes During Carbonization and Graphitization . . . . , ...... 31 4.3 Model Structures of Pitches...... 33 4.4 Carbon Fiber from Mesophase Pitch Flowsheet...... 221 4.5 Carbon Fiber from Mesophase Pitch Effect of Plant Capacity on Investment Cost...... 63 4.6 Carbon Fiber from Mesophase Pitch Effect of Operating Level and Plant Capacity on Product Value ...... 66 5.1 Carbon Fiber from Polyacrylonitrile Chemical and Molecular Changes During Production . . . . 68 l 5.2 Carbon Fiber from Polyacrylonitrile Effect of Fiber Length Change During Stabilization on Carbon Fiber Tensile Modulus...... 76 5.3 Carbon Fiber from Polyacrylonitrile Effect of Carbonization Temperature on Carbon Fiber Properties ...... 77 5.4 Carbon Fiber from Polyacrylonitrile Effect of Diameter on Carbon Fiber Strength...... 79 5.5 Carbon Fiber from Polyacrylonitrile Effect of Test Specimen Gage Length on Carbon Fiber Strength...... 80 5.6 Carbon Fiber from Polyacrylonitrile Effect of Carbon Fiber Density on Tensile Modulus...... 82 5.7 Carbon Fiber from Polyacrylonitrile FlowSheet...... 225 0 5.8 Carbon Fiber from Polyacrylonitrile Effect of Plant Capacity on Investment Cost...... 91 5.9 Carbon Fiber from Polyacrylonitrile Effect of Operating Level and Plant Capacity on Product Value ...... 94

vii ILLUSTRATIONS

6.1 A Schematic Diagram of the Rayon Graphitizing and Stretch%ng Orientation Process ...... 97 6 2 Carbon Fabric from Rayon FlowSheet...... 227 6.3 Carbon Felt from Rayon Flow Sheet ...... 229

Viii TABLES

2.1 Summary of Economics Carbon Fibers from Pitch, PAN, and Rayon...... 7 3.1 Carbon Fiber Producers...... 12 3.2 Current and Projected Carbon Fiber Production Capacities ...... 15 3.3 Past and Projected Consumption of PAN Based Carbon Fiber...... 17 3.4 Properties of Pitch-Based Carbon Fibers ...... 18 3.5 Properties of PAN-Based Carbon Fibers ...... 19 3.6 Japanese System of Carbon Fiber Classification. .... 22 3.7 Trademarks and Product Forms of PAN-Based Carbon Fibers ...... 24 3.8 Carbon Fiber Applications ...... 26 3.9 Comparison of Properties of Reinforcement Fiber Materials ...... 28 0- 4.1 Typical Physical Properties of Coal Tar and Petroleum Pitches ...... 35 4.2 Properties of Ashland A-240 Petroleum Pitch ...... 37 4.3 Patents on Carbon Fiber from Pitch...... 134 4.4 Exxon's Catalytic Bottoms Specifications...... 43 4.5 Carbon Fiber from Mesophase Pitch Design Bases...... 50 4.6 Carbon Fiber fran Mesophase Pitch Major Equipment and F.O.B. Prices ...... 55 4.7 Carbon Fiber from Mesophase Pitch Utilities Consumptions...... 56 4.8 Carbon Fiber from Mesophase Pitch Capital Investment...... 62 4.9 Carbon Fiber from Mesophase Pitch 0 Variable Costs...... 64 4.10 Carbon Fiber from Mesophase Pitch Production Costs...... 65 5.1 Patents on Carbon Fibers from Polyacrylonitrile .... 148

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5.2 Properties of Du Pont's Orion@ Acrylic Type 43s 0 Carbon/Graphite Fiber Precursor ...... 74 5.3 Carbon Fiber from Polyacrylonitrile Design Bases...... 83 5.4 Carbon Fiber from Polyacrylonitrile Major Equipment and F.O.B. Prices ...... 85 5.5 Carbon Fiber from Polyacrylonitrile Utilities Consumptions...... 86 5.6 Carbon Fiber from Polyacrylonitrile Capital Investment...... 90 5.7 Carbon Fiber from Polyacrylonitrile Variable Costs...... 92 5.8 Carbon Fiber from Polyacrylonitrile Production Costs...... 93 6.1 Patents on Carbon Fiber from Rayon...... 178 6.2 Carbon Fiber from Rayon Typical Characteristics of Rayon Filament Precursor ...... 101 6.3 Carbon Fabric from Rayon Design Bases...... 104 6.4 Carbon Fabric from Rayon Major Equipment and F.O.B. Prices, Fabric Cleaning and Impregnating Section ...... 108 6.5 Carbon Fabric from Rayon Utilities Consumptions...... 108 6.6 Carbon Felt from Rayon DesignBases...... 109 6.7 Carbon Felt from Rayon Major Equipment and F.O.B. Prices ...... 110 6.8 Carbon Felt from Rayon Utilities Consumptions...... 110 6.9 Carbon Felt from Rayon 0 Heating and Cooling Time Cycle...... 111 6.10 Carbon Fabric from Rayon Capital Investment...... 116

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6.11 Carbon Felt from Rayon Capital Investment...... 117 6.12 Carbon Fabric from Rayon Variable Costs...... , ...... 118 6.13 Carbon Fabric from Rayon Production Costs...... 119 6.14 Carbon Felt from Rayon Variable Costs...... 120 6.15 Carbon Felt from Rayon Production Costs...... 121 7.1 Patents on Carbon Fiber from Other Precursors . . . . . 184 8.1 Patents on Surface Treating ...... 188

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