Asahi India

Float glass is made by melting raw materials, typically consisting of sand, sodium carbonate, dolomite, limestone, and sodium sulfate. Other materials may be used as colorants, refining agents or to adjust the physical and chemical properties of the glass. The goal of the glass technologist is to use a glass recipe for maximum glass yield, efficient use of plant assets, at minimal costs to achieve the best quality product. Asahi India are the manufacturer of Float Glass India.

The raw materials are mixed and fed into a furnace that is natural gas or fuel oil fired at 1500°C. Common flat glass furnaces are 9 m wide, 45 m long, and contain more than 1200 t of glass. As the glass flows along the tin bath, the temperature is gradually reduced from 1100°C until the sheet can be lifted from the tin onto rollers at approximately 600°C. It then passes through the lehr where it is further cooled gradually so that it anneals without strain and does not crack from the change in temperature. The glass travels down the rollers in the Lehr for about 100 meters and comes out at the “cold end” where it is cut by machines.