Quartz glass or quartz material is produced in special high-temperature furnaces due to the high melting temperatures (approx. 3,630°F). The heart of such a furnace consists of a melting crucible, which is continually filled with quartz sand and heated to melting temperature.
The melting crucibles consist of riveted or pressed / sintered (seamless) tubes made of molybdenum or tungsten or a combination of Mo/W. 

The quartz glass tubes or rods are removed through an orifice. The heating system consists essentially of tungsten mesh or rod heating elements. To achieve or regulate the desired dimensions, a plug and plug pole made of refractory metals are necessary in addition to the orifice plate.
Areas of application for quartz glass are lighting technology, the semiconductor industry as well as fiber-optic technology. Quartz material is used for temperature measurement and also in the foundry industry.

PLANSEE USA supplies: Melting Crucibles and Orifice Plates Mandrels and mandrel shafts Heating Elements Accessories (Filling Funnels, Shields, Fastening Parts)