Optimization of Tensile and Impact Strength on Injection Molding Process Parameters of Biocomposite Material (Banana Fiber and Polypropylene) Using Taguchi Grey Fuzzy Method

Polymer Matrix Composite is a composite material with synthetic fibers that is widely used in industry. Polymer matrix composites reinforced with natural fibers are called biocomposites. Biocomposites can be used as the best alternative because they are environmentally friendly, biodegradable, corrosion resistant, non-toxic and have high mechanical properties. The biocomposites to be used for this research are banana fiber, melaic anhydride polypropylene (MAPP) with a composition of 10 Wt% banana fiber, 5 Wt% MAPP and 85 Wt% polypropylene. All these materials were mixed and extruded to form pellets. The biocomposite pellets were injected using an injection molding machine. The molded products were subjected to tensile test with ASTM D 638-03 type V standard, and impact test with ASTM D 256-04 standard. This study will optimize the process parameters of the injection molding machine to find the optimum tensile strength and impact strength using the Taguchi grey fuzzy method with an orthogonal matrix L27(3⁴). The process parameters that are varied include barrel temprature, injection pressure, holding pressure, and injection velocity, each of which has three parameter levels. From this research, a combination of injection molding process parameters that can significantly increase tensile and impact strength is obtained, with Barrel temperature 205 °C, Injection pressure 50 bar, Holding pressure 40 bar, and Injection velocity 75 mm/s.