Characterization and elastic property modeling of discontinuous carbon fiber reinforced thermoplastics prepared by a carding and stretching system using treated carbon fibers

Fiber alignment is a critical factor in the recovery of mechanical properties of recycled carbon fiber (rCF) composites. In this study, a carding and stretching system was introduced to improve the fiber alignment of rCF in an effort to generate card web carbon fiber reinforced thermoplastics (CWTs). Virgin carbon fibers were treated to replicate rCFs and ensure comparability between them. A series of mechanical tests was conducted on several types of CWTs, while X-ray micro-computed tomography scanning analysis was applied to evaluate fiber orientation distribution. The effect of alignment on CWT was also investigated analytically. Using such a technique, most of the rCFs were aligned within +/- 15 degrees. Meanwhile, satisfactory mechanical properties were also obtained in some stretched types of CWTs. Both laminate and netting theories showed good correlation with the experimental results. Overall, the netting theory was proved to be a useful tool for approximating the elastic properties of CWTs.