We can see glass everywhere we go from our windows, buildings, cars, tables, cups and many more. Some artists even use glass in making some piece of art. Sand, limestone and soda ash are the unique composition of a man-made glass.² They have to be heated to a molten status and then cooled quickly.

The production of glass involves two primary methods. One is the float glass process which creates sheet glass.¹ Second is the glass blowing which makes bottles and other glass containers.¹ Generally, current glass container factories have three-part operations: the batch house, the hot end, and the cold end.¹ The raw materials are being handled by the batch house. The manufacture proper such as the furnaces, annealing ovens and forming processes are being handled by the hot end. The product inspection and the packing equipment are being handled by the cold end.¹

The Glass Production Process:

All natural raw materials such as sand, limestone and soda ash and recycled glass, which are called cullet, are combined then these mixtures are being transferred to the furnace for melting. ³ This is the process where the molten glass is being formed into a new glass product. ¹ It started when a batch of glass is placed into the furnace at slow and controlled rate. The furnace is normally gas-powered that heats the components for about 1000 degrees creating molten glass.³

Currently, there are two main methods of making a glass container: the blow and blow method which is used to make narrow neck containers and the press and blow method which is used for jars and increasingly narrow neck containers. ¹ Both types, a stream of molten glass, is cut thru a shearing blade in order to form a cylinder of glass which is called a gob. ¹ All processes start with the gob falling in which the molten glass is being removed from the furnace and cooled into a uniform temperature and then cut into gobs. ³ Each of the gobs will simply form a single glass container.

The gobs are then transferred into forming machines where they can be shaped into glass containers. The formed containers will then pass through the lehr where the glasses are being reheated and slowly cooled to take away any stresses in the glass.³ This process actually helps strengthen the glass containers and prevents breakage.³

Each glass container will undergo through a thorough inspection stage in order to make sure it is in its highest quality and any containers that are rejected will be re-melted as cullet. ¹ The inspection can be done thru an automated machines, or sometimes persons.¹

The glass containers can be packed in various ways and after they are being packed, the new stocks are then being labeled and warehoused until they are being sent out to the consumers.

References:

1. http://www.absoluteastronomy.com/topics/Glass_production
2. http://www.ehow.com/how-does_5451812_manufacturing-process-glass.html
3. http://www.o-i.com/about_oi.aspx?id=1352