Tensile Properties of Manila Hemp Fabric Reinforced Cross-Ply Green Composites

This paper deals with the tensile properties of Manila hemp fabric reinforced cross-ply green composites. The composites were made from woven Manila hemp fibers as the reinforcement and starch-based emulsion-type biodegradable polymer as the matrix. Experimental results showed that their flexural strength increased with increasing the fiber content. However, the tensile strength increased with the fiber content until nearly 50mass% and leveled off thereafter. We found from the result of tensile tests that maximum tensile force of 0° ply sheets decreased with increasing the fiber content. This dependence on the fiber content is due to the decrease in the fiber strength caused by fiber's damages introduced during hot-pressing. In order to avoid the damage of fibers aligned in loading direction, fiber sheets were produced by using hemp fibers for warp and cotton threads for weft. As a result of using the cotton weft, the tensile strength of cross-ply green composites increased from 153MPa to 188MPa.