Like treacle, glass is fluid at high temperature and its fluidity decreases as the temperature is reduced. In other words, its viscosity decreases as the temperature increases. Unlike water, which turns from a liquid to a solid at a specific temperature, glass has no specific melting or freezing point, but is gradually changed from a stiff solid to a liquid mass as the temperature is increased. It is this property of “variable viscosity,” which is used in forming a mass of glass into articles of beauty or utility.
The different methods for forming a variety of different types of glasses either by hand forming, or machine forming, are described in the pages within this section:
- Container Glass Manufacture;
- Flat Glass Manufacture;
- Domestic Glassware Manufacture;
- Glass Blowing;
- Glass Fibre Manufacture;
- Optical Fibre Manufacture;
- Glass Tubing Manufacture;
- Lamp and Light Bulb Manufacturing;
- Light Bulb Manufacture.
Further information about secondary processes, such as the processes of annealing, toughening, coating and decoration are described in detail on the secondary glass processing page.
For information about the different types of glass produced, please see our types of glass section.
In this Section
The oldest examples of glass are Egyptian beads dating from 12,000 BC.