A New Recycling Technology for Carbon Fiber
Asahi Kasei, a diversified Japanese multinational company, has developed a new technology for recycling carbon fiber plastic compounds with the National Institute of Technology, Kitakyushu College and Tokyo University of Science.
Carbon fiber reinforced plastics (CFRP) are highly attractive for various industries in demanding application fields due to their unique balance of rigidity, mechanical strength and lightweight – compared with conventional glass fiber reinforced plastics. However, CFRPs are expensive and challenging from a recycling perspective, as it is difficult to extract carbon fibers 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 fibers to be extracted from CFRP or carbon fiber reinforced thermoplastics (CFRTP) used in automobiles.
According to the information, this results “in high-quality, inexpensive continuous carbon fiber that can be recycled perpetually, contributing to circular economy. Unlike carbon fiber chopped up during the recycling process, Asahi Kasei’s method allows carbon fiber to be extracted from a plastic compound seamlessly, resulting in continuous strands of carbon fiber that can be reapplied in exactly the same manner while retaining properties identical to the original substance”.
The conventional technologies for recycling carbon fibers 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 fiber to retain its original strength and continuous nature while fully decomposing the resin carbon fiber 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 fiber plastic compounds,” the company emphasized. “Thus, these carbon fiber compounds present in vehicles for weight reduction. It can be easily and inexpensively be broken down at end-of-vehicle-life and reapplied to new vehicles in the future.”
In addition, the company is developing a carbon fiber-reinforced thermoplastic unidirectional tape (CFRTP-UD tape) that utilizes both recycled continuous carbon fiber and the company’s Leona polyamide resin. Boasting a higher strength than metal, this CFRTP-UD tape could 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 fiber usage for vehicles has posed on the industry and is expected to economically benefit and strengthen carbon fiber’s usage within the automobile industry on a global scale,” Asahi Kasei is convinced.
“Moving forward, Asahi Kasei will perform demonstrations and develop the business, aiming for practical application around 2030.”
(Published in GLOBAL RECYCLING Magazine 1/2023, Page 40, (Photo: Asahi Kasei)
