Development of Compositions and Production Technology for Electrovacuum Tinted Glass

Abstract

The possibility of tinting industrial glasses with cadmium sulfoselenides is discussed. Glass compositions for making car headlights and their tinting technology are proposed. The melting and molding parameters for such lamp bulbs are identified. Experimental samples of yellow glass bulbs are obtained.The Brest Elastic Lamp Works JSC is one of the leading companies in the CIS producing a wide range of incandescent lamps for general and special purposes used in various sectors of industry, in illuminating civic buildings, and in transport vehicles. The company currently produces 36 types of automobile lamps used for illumination and signals in road equipment and vehicles. However, the present economic situation calls for renewing the product range and searching for new market niches. Among promising products one could include lamps with tinted glass bulbs that are extensively used in new design of automobile headlight and lighting systems, for instance PY21W lamps with a yellow glass bulb. The colorimetric and optical parameters of such glass should meet the following requirements of the MKO standard: light transmission over 65%, dominant wavelength 580 nm, and color frequency over 80%.At the first stage of the research, the researchers from the Department of Glass and Ceramic Technology at the Belarus Technological University and the technologists of the Brest Electric Lamp Works had to identify the type of colorants and glass compositions that could provide the specified parameters.The study of the transmission spectra and optical parameters of synthesized glasses tinted with carbon, sulfur, selenium, and cadmium sulfide indicated that only glasses tinted with cadmium sulfoselenides provide the required colorimetric and optical parameters of glasses and can be regulated within wide limits. Such glasses can be clear in melting, and a desired color shade can be "induced" in molding or in the course of special thermal treatment.At the second stage, we investigated the possibility of tinting clean glass by cadmium sulfoselenides in the work flow (in the feeder), which is a novel technique in the production of electrovacuum glass. The method implies using a feeder with a conversion chamber, to which colorant mixtures (pigment + low-melting component) are fed. The clear glass melt flow at a temperature of 1250 -1300°C is mixed with the colorant by a mixer. The specific feature of this glass-tinting technique is the possibility of a rapid transition from one color to another and back [1]. The experiments were conducted in laboratory conditions, simulating the conditions of the feeder converter in a heated crucible. The glass selected for tinting was electrovacuum glass SL-96 used at the Brest Electric Lamp Works to produce clear glass bulbs, which could allow the company to produce clear and tinted glass melt in the same furnace. The low-melting component in the colorant mixtures was represented by up to 4% (here and elsewhere wt.%) NaF and Na 2 SiO 3 (above 100%) with the pigment content equal to 0.1 -0.5% Se and 0.7 ...