-
MELTING AND REFINING
To make clear glass, need the right set of raw materials is required. This consists of silica sand (SiO2), sodium oxide (Na2O) from soda ash, calcium oxide (CaO) from limestone/dolomite, dolomite (MgO), and feldspar (Al2O3). These ingredients are mixed in the right proportion, and the entire batch is flown into a furnace heated to 1500 degrees Celsius.
To impart color to the glass, certain metal oxides are also mixed in the batch.
-
FLOAT BATH
The molten material from the furnace flows into the float bath, consisting of a mirror-like surface made from molten tin. This material enters the bath at 1500 degrees Celsius and leaves the bath at around 650 degrees Celsius. Its shape at the exit is like a solid ribbon.
-
COATING FOR REFLECTIVE GLASS
After that, if one is producing reflective glass surfaces that help keep indoors cooler, then coating procedures are followed in which either a hard coat or a soft coat is applied on the surface of the cooled ribbon at high temperatures.
-
ANNEALING
Next, a process called annealing is done to remove the internal stresses built up in the glass. This process allows the glass ribbon to pass through a layer that eliminates any pressures on the glass surface and gradually cools it to give it its final hardened form. This makes it easier to cut the glass and shape it accordingly.
-
INSPECTING
More than 100 million inspections can be made through acute and advanced inspection technology throughout the glass manufacturing procedure to identify air bubbles, stresses, or grains of sand that refuse to melt. This is essential in quality-proofing the final form of glass.
-
CUTTING TO ORDER
Finally, Laser cutting machine or diamond steels are used to trim and cut the glass ribbons into square shapes.
The Oldest Glass Factory
The first glass factory in the USA was established in 1608. It was founded near Jamestown, Virginia. Interestingly, this factory was also the earliest known factory in any English colony in America. Usually, the Germans were brought down there to work in the factory to make glass, sap, pitch, ashes, and tar, etc
