FIRING PBO-FREE GLASS ENAMELS USING THE CW-CO2 LASER

The firing of glass enamels, which are applied to decorate glass produ cts, is usually done in a furnace. A new and suitable technique for fi ring glass enamels is to make use of the high-power cw-CO2 laser. Its beam (wavelength 10.6 mu m) induces a very fast heating of the enamell ed glass within a small surface layer. This makes it possible to fire glass enamels at temperatures above 1000 degrees C, without any deform ation of the substrate glass body. In this temperature range an amount of the harmful component PbO in the glass enamel is no longer necessa ry. The PbO-free glass nux of the enamel is made easily by milling the substrate glass (neat glass). The gloss and smoothness of the laser-f ired enamel are comparable to the conventionally fired enamel. The abs ence of PbO and the high firing temperatures are very advantageous to the chemical resistance of the enamels, meaning excellent dishwasher d urability.