Thermal and Structural Property Characterization of Commercially Moldable Glasses

In this paper, we report the development of a kinetic model for precisely predicting glass material property response to a defined molding profile. The glass viscosity, thermal expansion, and specific heat properties for two commercial optical glasses, P‐SK57 and L‐BAL35 were measured and are reported in this paper. These data were used with the Tool–Narayanaswamy–Moynihan (TNM) model for glass structural relaxation in order to develop a thermal expansion model that simulates the glass workpiece changes through the critical cooling profile where the final workpiece shape is determined. The results show a structural relaxation model incorporated into an ABAQUS FEM code that precisely models the thermal expansion behavior acknowledging that the theory of structural relaxation is a critical element in predicting the final size and shape of a molded lens.