Question

For the manufacture of glass, various steps are given below. Arrange the steps in a proper sequence.
(a) Melting of raw materials
(b) Adding cullet to raw materials
(c) Conversion of raw materials to fine powder
(d) Annealing
(e) Refining

• A. a b c d e
• B. b a c e d
• C. c b a e d
• D. c b a d e

Answer 1

Answer: (C)

c b a e d

Manufacturing of glass involves:
(c) Conversion of raw materials to fine powder
(b) Adding cullet to raw materials
(a) Melting of raw materials
Melting process involves melting of raw materials. It is done in a furnace called open hearth furnace where it can produce heat more than 1900 degree Celsius. At a certain time we can see a glassy liquid is formed free of bubbles. This is the time to add salts if we desire to change the colour of glass. After melting process is finished it is cooled to 900 degree Celsius.
(e) Refining
This cooled melted glass can be formed into any shapes and any design using machinery work. Compression is done at this stage. and
(d) Annealing
Annealing refers to cooling of glass. The heat of the glass remains as such when obtained while melting. So glass is allowed to cool slowly. If it is done fast cracks occurs in glass. For better quality annealing is done for longer period of time.