Fiber aspect ratio effect on mechanical and thermal properties of carbon fiber/ABS composites via extrusion and long fiber thermoplastic processes

Abstract

The present study explores the effect of the aspect ratio of carbon fiber on the mechanical, thermal, and impact properties of carbon fiber-reinforced acrylonitrile-butadiene-styrene (ABS) matrix composites, which were produced using: (1) chopped carbon fibers with different lengths by means of twin-screw extrusion followed by injection molding; and (2) long fiber thermoplastic (LFT) pellets with different lengths by means of LFT followed by injection molding. The results revealed that the carbon fiber/ABS composites made by using carbon fiber/ABS LFT pellets exhibited the tensile, flexural, dynamic mechanical thermal, heat deflection temperature, and impact properties higher than those by using conventionally extruded carbon fiber/ABS pellets. It is noted that 12-mm-long LFT pellets contributed most to improving the mechanical and thermal properties of carbon fiber/ABS composites, compared to 6- and 24-mm-long LFT pellets. Meanwhile, the Izod impact strength of the composites was highest in the case of 24-mm-long LFT pellets. The improvements in the mechanical and thermal properties of carbon fiber/ABS composites were explained by different length distribution and aspect ratio of carbon fibers existing in the composites produced via conventional twin-screw extrusion and LFT processes, respectively.