Processing of unidirectional hemp fiber reinforced composites with micro-braiding technique

Natural fiber reinforced biodegradable composites are expected as alternatives of fossil fuel oil based composites. In case of using poly(lactic acid) as a matrix of natural fiber composites, It is difficult to impregnate reinforcement fiber yarns because of high viscosity of molten PLA. In this study, continuous hemp fiber reinforced thermoplastic composites were obtained using intermediate materials fabricated through a micro-braiding technique. Unidirectional composite plates were fabricated by hot press molding under various molding conditions, including molding temperature, pressure and time. At molding temperature of 190 °C, good impregnation was achieved, which result in good mechanical properties. At the molding temperature more than 210 °C hemp fiber and matrix thermally decomposed. Considering the tensile and shear properties, 190 °C-1 MPa-4 min is expected as an optimum molding condition.