Q. Describe the manufacturing process of glass.
Ans. Manufacturing process of glass
1. Melting: Raw materials, in proper properties mixed with pellets, are finally powdered and intimate mixture is fused in either finely pot or tanks part of an open hearth furnace, in which heating is done by burning producer gas and air mixture over the change. At high prevailing temperature the charge melts fuses. The melting process in case of ordinary soda glass involves following reactions.
CaCO3 + SiO3 = CaSiO3 + CO2
Na2CO3 + SIO2 = Na2SiO3 + CO2
When all the CO2 has escaped out of the molten mass, decolourizer are added and if coloured glass is desired then colouring agent is added, heating is continue till the molten mass is free from bubbles and glass balls, and then cooled to about 8000C.
2. Forming and shaping: Molten glass is then worked into articles of desired shapes by both blowing and moulding.
3. Annealing: The glass articles are allowed to cool gradually at room temperature by passing through different chambers with decreasing temperature, this is known as annealing.
4. Finishing: Cleaning, grinding, polishing, cutting, sand plastic etc. Are completed in this process.