Simulation of injection‐compression molding for optical media

Abstract

Abstract A numerical simulation of a coining type of injection‐compression molding is developed. A hybrid finite element/finite difference method is employed to model the temperature and pressure fields of the process using a non‐isothermal compressible flow model. Simulation results for CD‐R molding with respect to injection pressure and mold displacement are compared with experimental observations using an optical grade of polycarbonate. The simulation shows similar trends as experimental observations on the dependence of various processing parameters such as melt temperature, mold temperature, and packing pressure. However, the mold displacement measurement does not show the effect of punch delay time as does the simulation, and needs further investigation.