Compression Molding and Mechanical Properties of Green-Composite Based on Ramie/PLA Non-Twisted Commingled Yarn
Teruo KIMURA, Masahiro KURATA, Tatsuki MATSUO, Hirokazu MATSUBARA and Tadayuki SAKOBE
Abstract:In recent years, increased emphasis has been placed on developing the environmentally friendly biodegradable composites with the goal of protecting the environment. In this paper, the ramie/PLA biodegradable composites were molded and their mechanical behaviors were discussed. The non-twisted commingled yarn constructed with ramie and PLA fibers as reinforcement and matrix respectively was pre-molded to achieve the good penetration and dispersion of matrix and reinforcement. The compression molding with heating was performed to melt PLA fibers, and the green-composites reinforced by uni-directionally oriented ramie fiber were obtained. The volume fraction of ramie fiber was varied for wide range, and the tensile, bending and impact tests were performed for the molded composite. Especially, the results of bending test were compared with those of the composite based on the usual twisted commingled yarn. The microscopic observation was also carried out to examine the fracture mode of composite. It is concluded here that the fairly higher tensile and bending strength and modulus were obtained for our molded composites. This may be caused by the good penetration of matrix between fibers, good dispersion of fibers and also the uni-directionally oriented fibers. Especially, the impact value was fairly larger than that of PLA matrix at the higher volume fraction of ramie fiber. Key Words:Green-composite, Ramie fiber, PLA, Non-twisted yarn, Compression molding, Mechanical properties