Reuse of waste carbon fibre by compounding with thermoplastic polymers

Composites of Polypropylene (PP) and High Density Polyethylene (HDPE) with three types of continuous sized waste carbon fibres (CF) were manufactured using twin screw compounding. The carbon fibres used were collected as waste product form the 3D weaving process. Compounds with various percentages, between 4.6 % and 15.5 % fibre volume fraction, of reinforcement were injection moulded. Tensile testing was carried out to access the change in Young’s modulus, tensile strength and elongation at break. Also, micrographic analysis was conducted to observe the importance of sizing and the effect of its removal. It was determined that the Young’s modulus and tensile strength of the composite increased with increasing carbon fibre loading, whereas the elongation at break was reduced. Also, it was determined that an increase in tensile strength could be obtained by removal of the epoxy size.