Glasses

Glass is a super cooled liquid. The major ingredients of glass are sand, lime and soda ash. Borax increases the hardness and refractory character of glass. Glass dissolves in Hydrofluoric acid. Glass is a mixture of silicates. Boron Trioxide is used in the manufacture of glass for heat resistance. 

Different types of Glasses and Uses

1. Soda lime glass (soft glass/silica glass)

The components used in the manufacture of soda lime glass are silica/silicon dioxide (SiO2), sodium carbonate (Na2CO3) and calcium carbonate (CaCO3). They are used as window doors, mirror, bulbs, bottles and jar. Soda lime glass is also called as Soda Glass.

2. Hard glass (heat resistant glass)

The components used in the manufacture of hard glass are silica (SiO2), potassium carbonate (K2CO3) and calcium carbonate (CaCO3). They are used as laboratory apparatus, factory and kitchen wares. Hard glass is also called as Potash glass.

3. Boro silicate glass

The components used in the manufacture of Boro silicate glass are boric oxide (B2O3), aluminium oxide (Al2O3), silica (SiO2) and sodium oxide. They are used as laboratory apparatus, factory and kitchen wares. Thermometer is also made from Boro silicate glass. It is also called as Pyrex Glass.

4. Flint glass (optical glass/lead glass)

The components used in the manufacture of Flint glass are silica (SiO2), potassium carbonate (K2CO3) and lead oxide (PbO). They are used as lenses and prisms.

5. Fibre glass

It is also called fibrous glass, is glass in the form of fine fibres. The fibres may be many times finer than human hair and may look and feel like silk. The flexible glass fibres are stronger than steel and will not burn, stretch, rot or fade. Manufacturer use fibre glass to make a variety of products. Fibre glass is woven into cloth to make such products as curtains and table cloths. The cloth does not change its properties when dyed. It will not wrinkle or soil easily and needs no ironing. Fibre glass textiles are also used for electrical insulation. In bulk form, fibre glass is used for air filters and for heat and sound insulation. Air trapped between the fibres makes it a good insulator. The components used in the manufacture of Fibre glass are silica (SiO2), sodium carbonate (Na2CO3) and calcium carbonate (CaCO3). They are used as industry insulator, vehicles, helmets and furniture.

6. Safety Glass

Safety glass (manufactured by pasting a weightless plastic sheet in between two glass plates) is used in manufacture of bullet proof screens, wind shields etc. In 1902, french chemist Edouard Benedictus dropped a glass flask on a floor; he found that it shattered, but kept its shape. Examining it, he noticed a film to which the glass had adhered. The film came from an evaporation of a collodion solution. Aware that automobile passengers in accidents were injured by flying glass, he developed a coating that made the glass safe. During the 1920's, laminated windshields gained wide acceptance in the American automobile industry.