What is low hydroxyl quartz tube?
The water dissolved in quartz glass is called hydroxyl. Hydroxyl is the main impurity in quartz glass. The main factors affecting the content of hydroxyl are raw materials, processes and processing methods. As the hydroxyl content in the quartz glass changes, the properties of the quartz glass also change. As the hydroxyl content increases, the viscosity, density, and other properties of quartz glass decrease.
Dehydroxylation is to remove the free hydroxyl (-OH). When the UV lamp is working, the high temperature will penetrate the -OH in the quartz glass into the tube, and it will decompose under the action of the arc, thereby oxidizing and polluting the electrodes and the inside of the tube. Mercury reduces the service life of the lamp. Ordinary quartz tubes generally do not deal with hydroxylation, which means annealing and stress relief. The normal dehydroxylation temperature is 800-900℃, so that the hydroxyl group is about 10ppm; the high temperature dehydroxylation is 1000℃ or vacuum dehydroxylation, and the hydroxyl (OH)group is below 10ppm, and can even reach OH<5ppm, OH<2ppm.
The low-hydroxy quartz tube produced by advanced continuous melting technology has the characteristics of high purity, strong projection, clear appearance, and low hydroxyl content. It is mostly used in the manufacture of halogen lamps, mercury lamps, metal halide lamps, UV lamps and other quartz lamps.
We are a quartz glass supplier in China with strong resource integration ability.We can provide low-hydroxy quartz tubes with diameters from 1mm to 300mm and lengths from 10mm to 2.5 meters. Special sizes and shapes can also be customized according to your requirements.