Multi-Objective Optimization of Injection Molding Process for Determination of Feasible Moldability Index

Abstract

A multi-objective optimization of injection molding for determination of feasible moldability index was investigated in this study. The feasible moldability indices were calculated by implementing Taguchi method and Fuzzy Analytic Hierarchy Process with the order performance by its similarity to the ideal solution technique. Major process parameters of the injection molding like melt temperature, gate design, filling and cooling times were selected as variables to minimize common manufacturing defects like shrinkage, warpage and short shot. The analytic hierarchy process was used to set initial weights of variables and seriousness of each defect was evaluated by fuzzy decision-making process. Finite Element Analysis of the injection molding process was performed for selected work piece using polypropylene material. Results showed that it is more convenient to calculate several sets of variable parameters with high moldability indices, rather than focusing on single configuration with the highest moldability index. It is clear that the combination of Taguchi with TOPSIS and FAHP gives more applicable alternatives with high moldability indices, if the solution with highest moldability index in not practical.