Mechanical properties of polypropylene reinforced hemp fiber composite

Hemp fibers are one of the strongest and stiffest available natural fibers and therefore have great potential for use in composite materials. This paper investigated the impact response of reinforcing polypropylene (PP) by hemp fibers. Hemp fibers were added at (30 wt.%, 33 wt.%, 35 wt.%, 37 wt.%, and 40 wt.%). Influence of fiber’s content on composite tensile strength and strain were revealed and the results show that at 33 wt.% the tensile strength of PP and hemp fiber composites was improved by 12.75 %. At 33 wt.% the fibers were longitudinally, at 45 o , horizontally, and randomly oriented. The influence of fiber’s orientation on both stress and strain of the composites was studied and the results show that the tensile strength of the composites when the fibers were longitudinally oriented was higher than that of the other fiber’s orientation. Also the tensile strength of the composites at 33 wt.% was highly improved when the fibers were weaved and the tensile strength of the composite was improved by 25.98 %. The effect of hemp fiber on the hardness of PP was deliberated where the hardness of the composite was increased by 5.77 % better than that of pure PP.