STUDY ON THE INFLUENCE OF INJECTION MOLDING PARAMETERS ON THE WARPAGE AND SHRINKAGE IN HOT RUNNER SYSTEM MOLD

Abstract

The good combination of injection molding parameters (IMP) will make high quality product by elimination of defects occurred during injection molding process such as warpage and shrinkage. This paper investigates influence of IMPs on shrinkage and warpage on injection molding process using hot runner system. Taguchi method and ANOVA analysis are used to optimize the IMPs including melt temperature, filling time, injection pressure, packing pressure, coolant inlet temperature, cooling time, and flow rate. The analysis and simulation processes were done by using a Moldflow software. The plastic material is acrylonitrile butadiene styrene (ABS) with some features of the dimensional stability, chemical endurance, and simple processing capacity. The results show that melt temperature and coolant temperature are the main factors affecting the warpage with 66.67% of melt temperature and 15.59% of cooling temperature. The melt temperature and packing pressure are the main factors affecting the shrinkage with 74.62% of melt temperature and 19.46% of packing pressure. The optimal IMP is retested with warpage defect reduced 16.6% and shrinkage decreased of about 2.45% after optimization.