Development of 3D printing short carbon fiber reinforced polypropylene composite filaments

In this study, the 3D printing short carbon fiber (SCF) reinforced polypropylene (PP) composite filament was developed. The micro-size SCFs were mixed with PP granules and extruded in a twin screw extruder to develop SCF/PP composite granules. The composite granules were extruded in a single screw extruder and then wound to develop SCF/PP filaments. SCF/PP filaments were produced with varying content of SCF ranging from 4 to 22 wt%. The developed composite filaments were injected by a 3D printer to produce testing samples. 3D printed SCF/PP composites with different SCF contents were investigated by analyzing their mechanical, physical, and morphological properties. The SCF/PP composites developed have shown great enhancement in their mechanical properties (tensile strength and impact toughness). The tensile strength of the 22%SCF/PP composite increased by 150% when compared to the neat PP, while the impact energy of the 22%SCF/PP composite was enhanced by 260% of the neat PP. However, the strain at break values decreased linearly in composites up to 11 wt% SCF content followed by a sudden drop in strain values in composite with 14 wt% SCF.