Grey optimization of injection molding processing of plastic optical lens based on joint consideration of aberration and birefringence effects

The optical performance of injection molded plastic lenses is seriously degraded by the warpage and residual stress induced during the molding process. In particular, warpage produces optical aberrations, while residual stress causes birefringence. Consequently, it is essential that the processing parameters used in the molding process are properly assigned. Accordingly, the present study first applies the robust Taguchi design methodology to determine the processing conditions which independently minimize the warpage and residual stress of the molded lens, respectively. The two sets of parameters are then further analyzed using a grey relational analysis model to establish the processing parameters which simultaneously minimize both the warpage and the residual stress. The simulation results confirm that the joint optimization process yields an effective improvement in the quality of the injection molded lens.