Numerical simulation in compression molding of glass lens

Compression molding of glass lens is a promising and efficient fabrication process for high precision glass lens production. In this research, FEM simulations of the whole compression molding of a Plano-convex glass lens were conducted using the commercial code MSC Marc. By incorporating stress relaxation and structural relaxation model of glass during the transition temperature region, accurate predictions of the press load, volume change, temperature distribution and final residual stress within lens were obtained. Also, the simulation results indicated that the maximum geometric curve deviation of the molded lens was about 9 um. Furthermore, a methodology for mold compensation to reduce the curve deviation was proposed, and the revised molded lens using the compensated mold showed a much more accurate shape with the maximum curve deviation of about 0.04 um. FEM simulations have been demonstrated to be efficient and reliable in predicting the process and improving performance.