Carbon-fibre reinforced compounds may be much-prized material choices in demanding application fields, such as the automotive industry, because of their combination of rigidity, mechanical strength and light weight but at the end of life, they are notoriously difficult to recycle efficiently. Separating the fibres from the resin at the end of life is an expensive and challenging process.
Now, Asahi Kasei, a diversified Japanese multinational company, working in collaboration with the National Institute of Technology, Kitakyushu College and Tokyo University of Science, have developed a solution that allows carbon fibres to be extracted from CFRP or carbon fibre reinforced thermoplastics (CFRTP) used in automobiles.
The technology yields high-quality, inexpensive continuous carbon fibre that can be recycled perpetually, said the company. Unlike carbon fibre that is chopped up during the recycling process, Asahi Kasei’s method allows the fibre to be extracted from the compound intact, resulting in continuous strands of ‘virgin’ carbon fibre that can be reused in exactly the same application.
Recycling the fibres by chopping and then reusing them yields a product with lower quality and less durability, rendering them unsuitable for high-performance applications.
Asahi Kasei’s new electrolysed sulfuric acid solution method keeps the carbon fibre intact, allowing it to retain its original strength while fully breaking down the resin in which it has been embedded. The technology offers an inexpensive, circular solution for, in the future, recovering and reusing the carbon fibre used to achieve lighter weight vehicles in new vehicles.
Asahi Kasei are currently developing a carbon fibre-reinforced thermoplastic unidirectional tape (CFRTP-UD tape) that utilises the recycled continuous carbon fibre yielded through the new process and the company’s Leona polyamide resin.
The tape, which the company claims has a higher strength than metal, can be applied to automobile frames and bodies, further enabling the recycling of end-of-vehicle-life parts into different, new automobile parts.
The technology is expected to economically benefit and strengthen the use of carbon fibre in the automotive industry on a global scale. Practical applications are expected around 2030.