Optimising injection moulding parameters that satisfies part qualities by using Taguchi method

The main purpose of this research is to identify the most influenced injection moulding parameter to satisfy polycarbonate part qualities by using Design of Experiment (DOE) of Taguchi method. The part qualities selected in this research were warpage, shrinkage and ultimate tensile strength. Through this experiment, four most significant process parameters were chosen: melt temperature, injection pressure, packing pressure and injection time, base on previous research findings. By using Taguchi orthogonal array L₉ (3⁴), the signal to noise (S/N) ratio and analysis of variance (ANOVA) had been done. It was found that the most significant process parameter which posses the lowest value of defects (warpage and shrinkage) and optimum value of mechanical property (ultimate tensile strength) was injection time. In order to validate the experimental result, confirmation test has been done based on the set of best combination process parameters determined from S/N ratio. As the result, warpage and ultimate tensile strength were improved about 36.73% and 2.71% respectively, while for minimum shrinkage produce by the best combination parameters was 0.006598. As a conclusion, Taguchi method was recognized as the effective methods to be used to optimise the parameter setting and to predict and solve the quality problems that occur in injection moulded parts.