Optimization of the micro molding of a biconcave structure

Abstract

Micro molding is a rapid and cost-effective micro manufacturing technology. However, during the manufacturing process, different kinds of products usually face problems with uneven thicknesses or particular structure designs, resulting in uneven products shrinkage. This research focuses on exploring the problems of molding a micro part with biconcave structure and sharp edges. Using the Taguchi Experimental Method, it aims to find the critical molding parameters which influence the moldability of the micro part, as well as to minimize the shrinking of part. This study used polypropylene (PP) for the injection molding and successfully resolved the void defect which appeared in the center of this biconcave structure. Melt temperature contributed the highest percentage (41.235%) to the shrinkage, followed by injection speed (31.947%) and mold temperature (12.887%). The optimal process parameters for injection molding obtained from the experiment which are melt temperature 240°C mold temperature 90°C, and injection speed of 30 mm/s and the shrinkage rate is 1.641%.