Preparation :- i) Molten mass of alkali free glass is passed through sieve holes of 0.0005 cm diameter (5x10-4 cm). ii) The glass filaments obtained are the thrown over a rapidly rotating drum to get wool like form.
Properties :- 1) Its thermal conductivity is low 2) It is fire proof & non-combustible. 3) It has low thermal & electrical conductivity. 4) It is resistant to chemicals. 5) It is soft, flexible, has low density. 6) It is waterproof. 7) Its tensile strength is very high. 8) It is light in weight.
Applications : 1) It is used in air filters as a dust filtering material. 2) It is used as sound absorber (sound - proofing). 3) Being resistant to chemicals it is used for filtering hot, corrosive liquids like acids, alkali etc. 4) It is widely used as thermal insulating material in domestics & industrial appliances such as motors, ovens, refrigerators. 5) It is used in the manufacturing fiber glass by reinforcing with plastic resins.