Analysis and Simulation of Short Shot Defects in Plastic Injection Molding at Multi Cavities

This radiator cover mold has been made and has gone through the first pre-production trial stage (T0). However, the product experienced a short shot defect in the 1st cavity. After testing using Moldflow, there is a difference in injection time that is quite long between the 1st cavity and 2nd cavity. There is a need for a new design on the feeding system that can speed up injection time in 1st cavity, so differences in injection time can be minimized. The analysis is done by making variations of the size of the feeding system, which is: runner diameter, width, and thickness of the gate using Taguchi and ANOVA method. The analysis shows that the optimal design of the diameter runner is 8 mm while the size of the wide gate is 10 mm and the thick gate is 0.8 mm. The validation process is repeated using Moldflow with the result of a concise injection time difference is 0.001 s. The new design of feed system able to eliminate the difference in filling time in this product.