Investigation of The Influence of Injection Molding Parameters of Polypropylene/CNTs:GNPs Nanocomposites Using The Taguchi L9 Orthogonal Arrays

This research implemented Taguchi analysis to evaluate the influence of injection molding parameters on mechanical and electrical properties of polypropylene reinforced with 2 wt% hybrid nanofillers of CNTs:GNPs 80/20 that was suitable for static dissipation. This analysis was useful for decision-making in electronic packaging production. The L9 (34) orthogonal array was carried out, in which four important factors, namely injection velocity, mold temperature, holding pressure, and cooling time, were varied in three levels. Nanocomposites were melt-compounded and injection-molded into specimens. The degree of crystallinity (Xc) was studied to correlate with tensile modulus. Statistically, the signal-to-noise ratio and the one-way ANOVA were calculated to determine the percent contribution of each factor. It was found that mold temperature was the most influential parameter on tensile modulus and tensile strength at yield, while injection velocity was the most influential parameter on tensile strength at break and impact strength. Interestingly, the Xc of the specimens at the skin area correlated with mechanical properties that higher mold temperature and faster injection velocity favored higher Xc for rigidity enhancement. However, the specimens molded at the lowest level of these four factors had a surface electrical resistivity of an insulating material instead of a static dissipative material.