Classification of Glass based on Composition & Applications

Classification of Glass

Glass is usually classified into three main classes:

Soda lime glass

• It is obtained from the fusion of a mixture of silica, lime, soda and alumina.
• Powdered glass too may be added
• This glass is also termed as Soda-ash glass, Soda glass or Soft glass
• It is used for glazing doors, windows and making ordinary glass wares

Lead glass:

• It is obtained from the fusion of a mixture of silica, lead and potash
• Powdered glass too may be added
• This glass is also termed as Flint glass
• Lead glass has highly shining appearance
• It is not affected by temperature
• Cut glass work, electric bulbs and optical glass are made from it

Boro-silicate glass:

• It is obtained from the fusion of a mixture of silica, borax, lime, and feldspar.
• Powdered glass too may be added
• This glass withstands high temperature
• Laboratory equipment and kitchen utensils are made out of it

Commercial Forms of Glass

Glass is marketed in various commercial forms to suit varying field requirements.

Sheet Glass:

• Most extensively used in engineering works
• Size ► Thickness of 2, 2.5, 3, 4, 5 5.5 and 6.5 mm ► sheets up to 175 cm x 110 cm sizes are also available

Ordinary glazing quality: Used for general glazing

Selected glazing quality: Used for better quality works

Special selected quality: Used for superior quality works such as show cases etc

Plate glass:

• It is made in thickness varying from 3mm to 32 mm and sizes up to 275cm x 90cmm.
• It is stronger and more transparent than the sheet glass

Tempered plate glass:

• Glass plate is heated and then suddenly cooled to tamper it
• Tempered glass is much stronger than ordinary sheet glass.
• Used for glazing entrance doors, table tops, shelves, counters etc

Laminated glass:

• Two or more glass plates with intervening layers of transparent plastics are bound under effect of heat and pressure.
• This type of glass is not broken into pieces when it breaks
• Ensures safety at places where glass is liable to shatter
• Glazing windows and doors

Wired glass:

• It is a rough cast translucent (semi transparent) glass with special steel wire mesh of 0.46 to 0.56 mm dia.
• Wire mesh completely embedded between the layers of glass during manufacture process
• Fire resistant and safe during breakage

Insulating glass:

• Two layers of glass separated by 6mm to 12mm of air space are sealed to provide heat insulation

Colored glass:

• By adding oxides of metals to metal glass the finish product get colored
• Used for decoration works in building construction

Flint glass:

• It is lead glass which shines
• Used for glass work as optical glass, for making electric bulbs.