Processing and characterization of hemp fiber textile composites with micro-braiding technique

From the actual usage of natural fiber reinforced composites, textile composites are desired. In the present study, hemp fiber reinforced poly(lactic acid) composites were molded with micro-braiding technique. At first micro-braided yarn (MBY) was fabricated. Then, plain woven fabrics were weaved on a loom. In order to optimize molding condition, three molding conditions were selected based on the previous study on unidirectional composites. Tensile and shear tests were conducted on the specimens. Tensile and shear strength is highest for molding temperature 190 °C, molding pressure 1 MPa and molding time 4 min. Higher molding pressure induce pouring out of matrix from the mold die, which result in lack of matrix. At higher temperature, slight decomposition of hemp fiber also occurred. Cross-ply laminates and weft knitted composites were also molded for comparison. Tensile properties of textile composites were much lower than cross-ply laminates, because of undulation structures.