Impact Strength of Ramie/HDPE Composites Manufactured Using Hot Compression Molding

In this paper, natural fiber composites made of treated ramie yarn and high-density polyethylene (HDPE) matrix in powder form were manufactured using hot compression molding. The fibers were arranged to make unidirectional ([0°] and [90°]) and bidirectional [0°/90°]_s specimens. A Charpy impact test with a notch was performed to determine the impact strength of ramie/HDPE composites. Statistical analysis using two-parameter Weibull distribution with 50% reliability was used. The result showed that the unidirectional [0°] specimen has a higher impact strength than the bidirectional specimen. Meanwhile, the unidirectional [90°] specimen had the lowest impact strength. The morphology of the fracture surface was analyzed using scanning electron microscope (SEM). It revealed the dominant damage mode, i.e., fiber breakage and pull-out for the unidirectional [0°] specimen, matrix cracking for the unidirectional [90°] specimen, and the combination of matrix cracking and fiber pull-out for the bidirectional specimen.