Process simulation and optimization for injection molding - Experimental verifications and field applications

It is widely recognized that computer simulation enhances an engineer's capability in handling many important aspects of injection molding. However, there remains a gap between the numerical predictions and the ultimate objective of employing a simulation, which is to achieve the optimal design and process setup. To bridge this gap, work has been done to couple a process simulation tool for injection molding with an optimization package. This integrated system helps engineers determine the optimal design and processing parameters more efficiently and effectively. To ensure the reliability of the process simulation tool, experimental verifications have been conducted by comparing the predicted and actual linear shrinkage and pressure trace of injection molded test bars and optical retardation of an industrial precision optical lens. Further, process and design optimization has been performed for the optical lens to minimize the cycle time while keeping the optical retardation below a threshold. With the help of the automated integrated system, the overall optimization task can be accomplished in a single day instead of 10 days as required by the manual optimization approach. In addition, the new, optimized design and processing parameters significantly reduce the optical retardation in the optical lens.