As products made of carbon fiber reinforced polymers (CFRP) reach the end of their operational lifespan, conventional recycling techniques, such as pyrolysis, have demonstrated limitations by producing short and damaged recycled carbon fiber. Recently, chemical recycling techniques have become increasingly prominent due to their capacity to separate reinforcing fibers with minimal degradation. To fully leverage the benefits of chemical recycling for efficient production, it is essential to sort the length of recycled carbon fibers and produce quality recycled carbon fiber polymer composites (r-CFRP) with high efficiency. In this study, we propose a method for lengthwise classification of carbon fibers using the distinction movement of fibers exhibited in a rotational flow of a viscous medium. In order to elucidate the underlying mechanism, a simplified one-dimensional Couette flow model is implemented. Moreover, experiments are conducted to validate the classification efficiency of the proposed method.

Keywords: CFRP Recycling, Fiber classification, Recycled carbon fiber