Electric, thermal and sound insulating materials

ELECTRIC, THERMAL AND SOUND INSULATING MATERIALS

Insulating materials used for electric, thermal and sound resistance are described below.

1.  ELECTRIC INSULATORS

Electrical insulators are used to separate the conductors carrying electric current. They are non-metallic materials having high resistance to current flow. Mica, asbestos, porcelain, bakelite, rubber and wax are solid insulators for making switches and switch plates. Paraffin oil and chlorinated diphenyl liquid are liquid insulators used in transformers and rheostats.

Thermocol is a cellular plastic which is an excellent electric insulator. It is a very light, stable and durable material. It is used in refrigerators, air conditioners and cold storages.

2.  THERMAL INSULATORS

Air conditioning of rooms consumes considerable amount of electricity. The load on electricity can be considerably reduced by using thermal insulators. Thermal insulation may be achieved by providing air spaces between structural components or surface insulation. Aerated concrete and hollow bricks belong to the first category of thermal insulation. Gypsum boards, fibre boards, asbestos cement boards and reflecting paints act as surface insulators.

3. SOUND INSULATORS

Sound insulation is required in buildings to restrict noise levels. In auditoriums and cinema halls, sound insulation is a must. Apart from acoustic efficiency, a sound insulating material should possess resistance to moisture. It should be incombustible, light in weight and possess aesthetic appearance. Its maintenance cost should be less.

The commonly used sound insulating materials are concrete, asbestos, glass and mineral wool. Gypsum plaster is a very good sound insulator.