FLOAT GLASS

Float glass is manufactured through a process developed by Pilkington in 1959, taking flat glass technology to a revolutionary new level. The glass gains its lustrous finish and perfect flatness by floating on a bath of molten tin in a chemically controlled atmosphere. The ribbon of glass is then cooled, while still moving, until the surfaces are hard enough for it to be taken out of the bath without the roller marking the surface. The glass is then automatically cut and stacked, ready to be packed for distribution.

The Float Line

1. Raw material feed
   • Sand, soda ash, dolomite, limestone and a proportionate amount of cullet are combined to form a batch. Strict quality controls and monitoring of temperatures throughout the process maintain high quality standards.
2. Furnace
   • Batch materials are fed into the furnace. Full melting is achieved at around 1600°C.
3. Float bath
   • A continuous ribbon of molten glass floats along the surface of molten tin. Irregularities are melted out, ensuring flat, parallel surfaces in the glass.
4. Annealing lehr
   • The glass is annealed and gradually cooled to 200°C, to relieve stresses and prevent splitting and breaking in the cutting phase.
5. Cutting
   • The glass ribbon is cut automatically as it moves along the rollers.
6. Stacking and offloading
   • A series of automatic stackers offload the glass. The glass is then warehoused for distribution, using overhead cranes and mobile lifting vehicles.