Recycled carbon fibre for high performance energy absorption

Abstract

This paper compares the mechanical properties of virgin and recycled woven carbon fibre prepreg and goes on to assess the potential for recycled carbon fibre reinforced plastic (rCFRP) to be used in high performance energy absorption structures. Three sets of material were examined: fresh containing virgin fibres and resin, aged which was an out of life but otherwise identical roll and recycled which contained recycled fibre and new resin. The compressive strength and modulus of rCFRP were approximately 94% of the values for fresh material. This correlated directly with the results from impact testing where rCFRP conical impact structures were found to have a specific energy absorption of 32.7kJ/kg versus 34.8kJ/kg for fresh material. The tensile and flexural strength of rCFRP were 65% of the value for fresh material. Tensile and flexural moduli of rCFRP were within 90% of fresh material and ILSS of rCFRP was 75% that of fresh.Overall rCFRP has been proved to remain a highly satisfactory engineering material. This is a significant finding as it proves that carbon fibre can be recycled and reused in high performance applications. This has significant implications for use of carbon fibre in the automotive industry where End of Life Vehicle (ELV) legislation requires 85% of materials to be recyclable. This work opens the door to significantly expanded use of carbon fibre in the automotive industry. Of equal significance is the finding that the mechanical properties of fresh and aged carbon fibre were all within ±6% of one another. This highlights an opportunity to understand resin system life in more detail in order to prevent the creation of composite waste at source.