Other Inorganic Glasses Based on Fundamental Glasses
The above glasses are the fundamental glasses. The types of glasses given below are manufactured using these fundamental glasses.
- Pyrex Glass or Jean Glass
Composition- These glasses contain virtually only silica and boron, with a small amount of aluminum and some alkali oxides.
Properties- They have low thermal coefficient of expansion, high chemical resistance very high softening point and high resistivity.
Uses- Used in industries of pipe lines, gauge glasses, superior laboratory glasses, kitchenware, chemical plants, and television tubes.
Composition- they are made up of mainly aluminum and silica, with a small amount of boron and alkalis oxides.
Properties- They have comparatively high softening temperature.
Uses- Used for high mercury discharge tubes, chemical combustion tubes, domestic equipment.
- 99.5% Silica or Vitreosil
Composition- It is produced by heating pure sand, i.e. SiO2 (quartz)
Properties- They have high viscosity, shaping is difficult, and the thermal expansion is low.
Uses- Used for chemical plants, chemical laboratory wares, electrical insulating materials in electric heaters, furnaces.
Composition- It contains phosphorous and lead silicate, together with cerium oxide.
Properties- They are capable of absorbing ultraviolet rays, have low melting point, and are relatively soft.
Uses- Used for making lenses.
Composition- They are made by using two or more plates of glass separated by 6 to 13 mm thick gap, filled up with dehydrated air.
Properties- They are transparent units and provide high insulation against heat.
Uses- Used for separating apartments.