Properties and uses of glass

Properties of glass

• Transparent (or translucent), allowing light to pass through, with a smooth, glossy surface.
• Hard but brittle: Strong in compression but weak in tension; it breaks suddenly without warning.
• Chemical resistance: Not attacked by water, air or most acids (except hydrofluoric acid); it does not corrode.
• Non-porous and impervious: Easy to clean and hygienic.
• Poor conductor of heat and electricity: A good insulator.
• Low thermal expansion (for borosilicate), but ordinary glass may crack with a sudden temperature change.
• Workable: It can be coloured, and moulded, blown or drawn when hot; it can be cut and polished when cold.
• Recyclable. Density about 2500 kg/m³.
• Affected by alkalis over a long time.

Uses

• Glazing of windows, doors, ventilators, skylights, curtain walls and partitions.
• Glass blocks and tiles for walls and floors.
• Mirrors, shop fronts, table tops.
• Insulation in glass wool and fibre-glass reinforced plastics.
• Safety applications: toughened and laminated glass for doors, stairs, railings.
• Lighting fixtures, pipes, tanks and laboratory equipment.