Comparison of Microcellular Injection Molding Process and Conventional Injection Molding Process

The warpage, residual stress, molding pressure, and temperature field in microcellular injec- tion molding were compared with those in conventional process. Based on theology theory, the microcel- lular injection molding mechanism was disclosed. It showed all the warpage, residual stress, molding pressure, and molding time of the microcellular injection molding were obviously smaller than those of conventional molding. The warpage and residual stress decreased with decreasing initial filling volume fraction of the foaming melt. For microcellular injection molding, a lower melt temperature near the gate and a higher melt temperature were needed than those for conventional injection molding.