Japan's Asahi Kasei develops recycling technology for carbon fibre

Carbon fibre reinforced plastics (CFRP) are highly attractive for various industries in demanding application fields due to their unique balance of rigidity, mechanical strength and light weight – also compared with conventional glass fibre reinforced plastics. However, CFRPs are expensive and challenging from a recycling perspective, as it is difficult to extract the carbon fibres from the resin after usage. 

Together with its project partners at the National Institute of Technology at Kitakyushu College and the Tokyo University of Science, Asahi Kasei has developed a recycling method that allows carbon fibres to be extracted from CFRP or carbon fibre reinforced thermoplastics (CFRTP) used in automobiles. This results in high-quality, inexpensive continuous carbon fibre that can be recycled perpetually, contributing to circular economy. Unlike carbon fibre that is chopped up during the recycling process, Asahi Kasei’s method allows carbon fibre to be extracted from a plastic compound seamlessly, resulting in continuous strands of carbon fibre that can be reapplied in exactly the same manner while retaining properties identical to the original substance, the company said in a media statement.

The conventional technologies for recycling carbon fibres by chopping and re-applying them results in a product with lower quality and less durability, insufficient for high-performance applications. To address this issue, Asahi Kasei has developed an electrolyzed sulfuric acid solution method that allows the carbon fibre to retain its original strength and continuous nature while fully decomposing the resin the carbon fibre is embedded in. This allows for its continued use in high-performance applications and presents an inexpensive, circular solution to the end-of-life dilemma of carbon fibre plastic compounds. Thus, these carbon fibre compounds are present in vehicles for weight reduction. It can easily and inexpensively be broken down at end-of-vehicle-life and reapplied to new vehicles in the future. 

In addition, Asahi Kasei is developing a carbon fibre reinforced thermoplastic unidirectional tape (CFRTP-UD tape) that utilises both recycled continuous carbon fibre and the company’s Leona polyamide resin. Boasting a higher strength than metal, this CFRTP-UD tape can be applied to automobile frames and bodies, further enabling the recycling of end-of-vehicle-life parts into different, new automobile parts. This presents a solution to the long-term challenge that carbon fibre usage for vehicles has posed on the industry and is expected to economically benefit and strengthen carbon fibre’s usage within the automobile industry on a global scale. Moving forward, Asahi Kasei will perform demonstrations and develop the business, aiming for practical application around 2030. 

Fibre2Fashion News Desk (GK)