Optimization of injection molding parameters for Kenaf/PP composite using Taguchi method

Injection molding has become the most probably important method of processing in order to fabricate excellent surface finish of complex geometric components with good dimensional and specification properties. However, molded polymers composites possibility being effected by machine parameters and other process condition that may cause poor quality of composites product. Thus in this study, composite of thermoplastic polypropylene (PP) reinforced with kenaf filler were prepared using a sigma blade mixer, followed by an injection molding process. To determine the optimal processing of injection parameters, Taguchi method with L-27 orthogonal array was used on statistical analysis of tensile and flexural properties of kenaf/PP composites. The results obtained that optimum parameters are: injection temperature 190 degrees C, injection pressure 1300bar, holding pressure 1900bar and flow rate 20cm(3)/ s. From the analysis of variance (ANOVA), both injection temperature and flow rate give highest contribution factor to the strength properties of the composites.