Development of Small-Scale Injection Molding Machine for Biocomposite Material from Agricultural Waste Fibers
Agriculture plays an important role in the Philippines, as it employs a sizable portion of 42.5% of its geographical area. Managing agricultural crop residue in the country is difficult, resulting in environmental pollution. Researchers are investigating the use of agricultural crop residues, such as rice straw and coconut husk, as natural fibers in biocomposites. Combining renewable reinforcement with bio-based matrices, these materials offer manufacturing options.
Injection molding is a promising method for manufacturing high-quality biocomposite materials, but it must be improved to accommodate emergent options. Three different designs were assessed with one undergoing fabrication. In addition, the exploratory experiment was led to determine different independent variables of the product to assess the best fiber-matrix ratio that will conduct in the final experiment. This research seeks to design an injection molding machine capable of transforming agricultural waste fibers and bio-based matrix into biocomposite materials.
Material testing of the injection-molded biocomposite materials is based on ASTM D3039 for tensile testing and ASTM D5229 for water absorptivity. The investigation shows that increasing the mold temperature will also increase the tensile strength of biocomposite material. Moreover, increasing both the mold temperature and fiber ratio will have higher elastic modulus. An increase in mold temperature resulted in a lower elastic modulus. However, increasing the fiber ratio resulted in a higher elastic modulus. The water absorptivity of biocomposites increases with mold temperature and decreases with fiber ratio due to the hydrophilic nature of thermoplastic starch since the higher starch content leads to a lower fiber ratio.
