Manufacture of Glass

The manufacture process :

1. The basic ingredients used in manufacture of glass are silica , limistone and soda ash . 
2. These ingredient are first ground finely and mixed in a proper proportion . The mixture is known as frit 
3. Cullet (broken or scrap glass )are fed also into the furnace to cause initial melting action , resulting in a sticky mass full of bubble . 
4. Further heating will cause loosing its viscous nature and become watery liquid , allowing all bubble to rise to the surface .
5. The molten glass is cooled and it is worked and shaped (formed ) when it is viscous . 

Glass products are produced by several basic processes , or method such as .

1. Blowing by mouth 
2. Drawing 
3. Casting by float 
4. Rolling 
5. Pressing or Extrusion . 

Forming Process /Method

• Blowing + Moulding  (blowing by mouth ) 
• This process is used to make small glass product . This involves blowing the viscous glass into shapes . 

Application .

• Used to make / manufacture : Antique sheet glass and sand bottles . 

Forming Process /Method

2) Drawing

• The molten glaurs is put into a tank .
• An iron grille known as a 'bait" is lowered into the tank . 
• The molten glass sticks to the grille and it is slowly lifted up , thereby drawing with it a sheet glass  . 
• The sheet of glass passes through annealing tower as it is pulled up . 
• The glass is then gradually cooled as it get higher . 
• The glass is cut , inspected , stored and dispatched .

Application
-Used to make sheet glass ( for window ) .