The material

After refining, the molten glass is cooled down to forming temperature and transported into the forming machines. The wide range of forming machines which are available reflects the wide range of glass products which they are used to make.

• Most sheet glass is today produced in the float process, which involves the molten glass flowing over a molten tin bath to produce flat glass of a very high quality. Rolling and drawing machines are used to make sheet glass with special properties or a textured surface.
• IS (individual section) machines are mainly used for the production of container glass, which is formed in a two-stage process. First the gob is produced in a preliminary mould and then blown out into the final mould cavity to create the finished product.
• In fibre glass production, a differentiation is made between continuous fibres and stable fibres. Continuous fibres are continuously drawn through bushings, which are platinum containers with a lot of extremely fine nozzles. The fibres are generally used for textiles or by the electrical industry as e-glass (a glass with high electrical resistance for circuit board production).
• Glass fibre insulation is another important glass fibre manufacturing segment. The majority of it is fiberised in the TEL process which involves fibres being spun in a rotating basket and then drawn out further by a fast air jet. Glass fibre insulation is mainly used to insulate buildings, though it is also used for automobile construction.
• Glass tubes, such as the tubes used in lamps, are produced in a continuous drawing process. The glass making industry uses the Danner process to make glass tubes, which involves the molten glass falling onto a rotating, slightly downward pointing mandrel and being drawn off by a tractor mechanism. In the vello process, the glass flows vertically down through a ring containing a rotating conical-ended shaft over and around which the glass flows. Then, the tube shaped glass is pulled from the end of the shaft by a tractor machine.
• A wide range of products are produced by pressing or casting. These include the screen glass which is used in picture tubes or tableware glass products such as vases and bowls, and also diffusing panels for car headlamps and lenses, which are partly cast and partly pressed. After forming, most glass products then go into the annealing ovens or lears as they are also known.