Mechanical Properties of Binder-Free Green Composite Using Bamboo Fibers

Abstract

Bamboo (Phyllostachys pubescens) fibers obtained by using a steam explosion method were hot pressed under various molding conditions such as temperature and pressure in this study. The effects of these molding conditions on the bulk density, tensile strength, and flexural strength are examined. Furthermore, the effect of the heating temperature on the mechanical properties of bamboo fiber bundles 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 decreases in the void content. This is because of the plastic deformation of parenchyma cells of bamboo fibers as the molding temperature rises. The tensile and flexural strengths of the unidirectional composite depend on the molding temperature. These strengths increased with the molding temperature up to 130°C as well as with the bulk density. These increases in the strengths were achieved by improved adhesive property. However, the strengths of the composite decreased above 130°C due to the decomposition of the bamboo fiber by heating. Thus, it was clarified that the optimum molding temperature was approximately 130°C. In addition, it was confirmed that the molding pressure has less effect on the bulk density, the tensile strength, and the flexural strength of the composites.