The glass molding process is considered to have a great potential for the mass production
of aspherical glass lenses with high precision and low cost. However, glass molding has a serious
problem of mold sticking with glass which needs to be resolved. This research investigates the
interface reaction between glass and mold by high temperature wetting experiment, which provides
the reference for the designing anti-stick coatings. The SUMITA K-PSK200 optical glass gobs with
low Tg were used in this study. The influence of operation temperature, ambient gas, substrate
materials, and thin film composition on wettability of glass at high temperature were studied. The
results show that the higher the temperature, the smaller the wetting angle between glass gob and
substrate could be observed. This indicates that severe interface chemical reaction occured and
resulted in the loss of transparency in glass appearance. The wetting experiment in nitrogen ambient
improved the sticking situation. The combination of chemically stable substrates and coatings, such
as Sapphire (substrate) / GaN (film) and Glass (substrate) / Al2O3 (film) can achieve the best antistick
propose. The precious metal films, such as Pt, Ir, coated on the ceramic substrates can
effectively reduce the interface reaction between the glass and substrates.
Numerical Simulation of Glass molding Process for Large Diameter Aspherical Glass Lens
