The use of carbon fibres has been growing exponentially, prompting the development of sustainable recycling routes for the carbon fibre reinforced polymer (CFRP) waste generated.
Mechanical and thermochemical (e.g. pyrolysis) fibre reclamation processes are reviewed, and it is shown that, under optimised conditions, most processes can recover fibres with virtually no degradation of mechanical and electrical properties.
Reintroducing the fibres into new composites is challenging because of their unstructured form, thus requiring extra processing; nonetheless, the mechanical properties of recycled CFRPs compete with those of glass fibre composites, aluminium and even virgin CFRPs.
It is expected that recycled composites will be applied mostly in non-safety critical components for the transport industry, in which case life cycle assessment suggests that recycling is greener than landfilling or incineration. Non-structural applications are also reviewed.
Some of the challenges ahead – namely establishing a sound CFRP recycling chain, understanding the complex response of recycled composites and optimising industrial scale processes – are discussed.
Handbook of Recycling: State-of-the-art for Practitioners, Analysts, and Scientists (ISBN: 978-0-12-396459-5) is a review of the current state-of-the-art of recycling, reuse and reclamation processes commonly implemented today. The book addresses several materials, including iron, steel, aluminium and other metals, pulp and paper, plastics, and glass. It also details various recycling technologies as well as recovery and collection techniques.