The Glass Molding Process (GMP) produces large quantities of glass optical parts and provides the advantages of high molding accuracy, short production cycle, low cost, and little pollution. Developments in different sectors, such as cameras and telescopes, are prompting studies on the design of aspherical optical components. Modeling heat transfer and deformation at high temperatures are crucial aspects of studying glass because its properties are significantly influenced by temperature-induced phase changes. In this study, temperature changes and geometric deviations of lenses were studied with respect to heating, pressing, and cooling times and the heat capacity of the heater used. A 3D model was designed for the heating, pressing, and cooling steps, and heat transfer was subjected to numerical analysis considering the specific heat of glass and the temperature dependence of thermal conductivity. Lens molding temperature conditions were then analyzed with the heat capacity of the lens molding heating system. Lens molding conditions were derived by analyzing lens temperatures with respect to heating and cooling capacities at each process step.

The purpose of this study is to propose a better contact surface pattern of a heat radiating block in a progressive GMP (Glass Molding Process) heating assembly. In this study, a simulation model based on FEM was developed to perform a thermal analysis for the heating assembly. It was verified by comparing experimental results. The temperature distribution on the heating block surface and heating energy consumption was analyzed with the change of contact surface pattern and area of a heat radiating block. The considered pattern on the contact surface was cross (+) and straight (-) shape. The contact area ratio was changed from 16 to 100%. The simulation results show that the heating energy consumption increased to reach a target temperature with the increase of contact area ratio. The straight-shaped patterns on a heat radiating block presented more uniform temperature distribution on the mold heating surface than the cross shaped surface, whereas it resulted in a slightly higher energy consumption of up to 9%. This study shows that the contact surface pattern on a heat dissipating block can control the temperature distribution on the mold heating surface.