Improved Gate System for Scrap Reduction in Injection Molding Processes

Abstract

This paper introduces a new geometry of the gate system in injection moulding process. The corners of existing edge gates results in the turbulence of molten plastic into the cavity which leads to internal and external defects. The aim of the new geometry is to reduce the internal and external defects of injected parts. Also easier de-gating of final part for the new geometry which decreases the visible blemish of final part after de-gating is a target of this study. A new design of edge gate is suggested for two circular flat plates with a thickness of 1mm. Internal and external defects in the plastic part are analysed with SolidWorks Plastics to validate the proposed geometry. The contribution of this research is to modify the geometry of existing edge gate by removing the corners of rectangular edge gate to reduce the scrap rate of injected parts. Also, a smooth flow of molten plastic into the cavities reduces the internal and external defects. The outcome demonstrates filling the cavities with no short shot. Also, no weld lines, meld lines or sink marks were detected with new design of the edge gate. Finally, the injected part with new design of the edge gate has less visible blemish in comparison with existing edge gate.