A study of thin shell plastic part quality in the plastic injection molding

Abstract

As the part’s dimensions become smaller, its thickness becomes smaller. In plastic injection molding, the production of the thin walled parts is very difficult. It’s hard, because melted plastic cannot easily fill the mold cavity. Because of this, the most important problem in thin walled parts is warpage. Besides warpage, the other problem that affects the thin shell part surface is shrinkage, sink mark and weld line. The best way to prevent this problem is to choose the plastic material and injection parameters right. This research deals with the application of Taguchi optimization technique to reduce warpage, shrinkage, sink mark and weld line variation depended on process parameters during production of thin-shell plastic part. For this purpose, a number of MoldFlow analyses are carried out by utilizing the combination of process parameters based on two level for one factor and three level for eight factor for eighteen experiment 1 7 L182 (3 ) Taguchi orthogonal design. The signal-to-noise (S/N) and the analysis of variance (ANOVA) are used to find the optimum levels and to indicate the impact of the process parameters on warpage, shrinkage,sink mark and weld line.