Flat drawn process

Flat drawn or Fourcault process involved drawing the molten glass upwards out of a bath and allowing it to cool as it is lifted into the air. This would ensure a transparent but distorted sheet of glass.

This was done using a straight metal bait which would be lowered into a bath of molten glass, which would then draw a continuous sheet of glass. To create large sheets of glass a tower was built to allow the metal bait to continue rising uninterrupted. The glass was gradually cooled and hardened as it rose through the tower.

To prevent the edges of this sheet of glass ‘necking in’ rollers were used to keep the sheet as flat as possible. The rollers would also help cool the glass and stiffen it into shape.

After the full height of the tower was used, the glass was cut into sheets at the top of the tower and the sheets were lifted off at the top.