This document discusses research into recycled carbon fiber composites conducted by the Institute for Maintenance Science and Technology. It summarizes their work with partners to develop recycling techniques for carbon fibers from aircraft and other composites. Their research demonstrated that recycled carbon fibers can be used to create new composites through vacuum assisted resin transfer molding and bulk molding compounds that exhibit comparable mechanical properties to virgin carbon fiber composites. The document outlines the recycling process and results of testing recycled carbon fiber composite materials and properties.

1. Institute for Maintenance Science and Technology RecyCled Carbon Fiber Composites Joseph Heil, Dr. Jerry Cuomo www.imst.us Carbon Fibre Recycling and Reuse November 4, 2009

2. Outline IMST Composite Sustainment Activities Partners in Carbon Fiber Recycling Recycled Carbon Fiber Composites Vacuum Assisted Resin Transfer Molding (VARTM) Bulk Molding Compound (BMC) Injection Molding Mechanical Properties of Recycled Carbon Fibers 2

3. Composites Sustainment Activities Reverse Engineering NDI Atmospheric Plasma Carbon Fiber Recycling Composites Manufacturing Repair Technologies Economic Development Training Activity Technical Support 3

5. Recycled Carbon Fiber Composites Vacuum Assisted Resin Transfer Molding (VARTM) AS4 Laminates IM7 Laminates Bulk Molding Compound (BMC) Injection Molding 5

7. Recycled IM7 laminates

9. VARTM Mechanical Properties: IM7 Laminates 8

10. VARTM Key Points Leaving the weave intact during recycling allows for laminate construction of RCFRP Reduced tensile strength of fibers & possible poor resin to fiber adhesion resulted in weak laminates VARTM allows for quick & easy comparison of different recycling treatments 9

11. Recycled Carbon Fiber Composites Vacuum Assisted Resin Transfer Molding (VARTM) Bulk Molding Compound (BMC) Injection Molding Fuel Cell Plates @ BMCI Circuit Breaker Panel @ Penn Compression Molding 10

13. 3000psi molding pressure

14. 160oC for 60sMechanical Testing: Tensile ASTM D3039 Flexure ASTM D790

16. 99% Flexure retention

17. Comparable to 5wt% loading glass/polyester

19. Six combinations of pressure and time

20. Difficult to wet out fibers

21. ~65 wt% phenolic resin

22. Added resin lowered viscosity

24. Recycled Carbon Fiber Composites Vacuum Assisted Resin Transfer Molding (VARTM) Bulk Molding Compound (BMC) Injection Molding Process of Making CFRP Fiber History Extrusion Compounding Injection Molding Trials Mechanical Testing 15

25. From Junk to Recycled Carbon Fiber Composites How do I get a CFRP? Recycle the Fiber Analyze fiber properties Mix with resin Mold Test Composite properties 16

26. End of Life Parts – Shredded and Sorted at Huron Valley Fritz West in Tucson, Arizona Reclamation of Fiber by Recycled Carbon Fiber, Ltd Birmingham U.K 350˚F Cure Epoxy with AS4 Fiber Control Unsized AS4 Reclamation of Fiber by Adherent Technologies Albuquerque, NM Characterizationby NC State with Direction and Oversight by Boeing Fiber History 17

27. Extrusion Compounding 18 c Carbon Fiber b a CFRP Pellets H2SO4 + H2O2 Ceramic Filter H2SO4 + H2O2 waste

28. Injection Molding Trials 19

29. Mechanical Testing Results 20 Tensile: ASTM D 638 Flexure: ASTM D 790

30. Impact Tests 21 PC Control: 60ft-lb/in

31. Injection Molding Key Points A clean fiber supply is needed Chemicals left over from recycling can impede bonding to resin Fiber does not flow freely Excellent mechanical properties Future work: engineering thermoplastics 22

32. Outline IMST Composite Sustainment Activities Partners in Carbon Fiber Recycling Recycled Carbon Fiber Composites Mechanical Properties of Recycled Carbon Fibers T300 & AS4 T800s Interfacial Shear Strength 23

34. T800s Elastic Modulus 27

37. Acknowledgments Brian Allen, Myles Connor, Brad Hartman, Davis Litzenberger, IMST Tom Hunter, Firebird Advanced Materials Pete George & Bill Carberry, The Boeing Company IntertechPira 30

38. Questions Contact Information Joseph Heil jpheil@ncsu.edu www.imst.us 31