Effect of Molding Conditions on Mechanical Properties of Binderless Bamboo Fiber Green Composite

Abstract

Hot pressing of bamboo (Phyllostachys pubescens) fibers that were obtained by using steam explosion was carried out under various molding conditions such as temperature and pressure. In this paper, the effects of the molding conditions on the bulk density, tensile strength, and bending strength are discussed. Further, the effect of the heating temperature on the strength of a single fiber bundle is also examined. The experimental results reveal that the bulk density increased with the molding temperature up to 130°C and was saturated at a constant value above 130°C due to a decrease in the void content. This is because of the parenchyma cells of the fibers melt as the molding temperature rises. The tensile and bending strengths of the composite depend on the molding temperature. These strengths increased with the molding temperature up to 130°C as well as with the bulk density. This increase in the strengths was achieved by improving the adhesive property. However, the strengths of the composite decreased above 130°C due to the decomposition of the single fiber by heating. Thus, it was clarified that the optimum molding temperature was approximately 130°C. In addition, it was also clarified that the molding pressure has no effect on the bulk density, the tensile strength, and the bending strength of the pressed products.