Improved Homogeneity Of Various Glasses By Gas Film Levitation

Heavy-metal fluoride glasses of the system ZrF4-BaF2-LaF3-AlF3-NaF and soda-lime-silica glasses, both from industrial and laboratory crucible production, were processed by the gas film levitation technique. In this process, the glass melt is suspended contactlessly on a thin gas film, avoiding any reactin witht he crucible material. This prevents chemical contamination, surface defects and heterogenous nucleation, which is especially advantageous for the preparation of speciality glasses.