The Firing Of Enamels Onto Borosilicate Glass Through The Selective Absorption Of Infrared Radiation

Graduations and markings on laboratory glassware such as beakers, flasks, measuring containers etc., must, to a large extent, be resistant to acids and alkalis, as the glassware usually comes into contact with aggressive chemicals in daily use and during cleaning. Glass enamels are often used for these markings. The aim of this paper is to find a firing process for glass enamels that ensures the same chemical resistance as furnace firing, but without the risk of changing the volume. This was obtained by a combination of conventional heating by a hot-air blower and selective heating by absorption of infrared radiation. A halogen lamp and an Nd-YAG laser were used as infra-red sources. The use of the laser clearly showed the best results.