Float Glass for Windows

Window glass
How is float glass made?

At the heart of the world’s glass industry is the float process – invented by Sir Alastair Pilkington in 1952 – which manufactures clear, tinted and coated glass for windows, and clear and tinted glass for vehicles. Float glass uses common glass-making raw materials, typically consisting of sand, soda ash (sodium carbonate), dolomite, limestone, and salt cake (sodium sulfate) etc. The process, originally able to make only 6mm thick glass, now makes it as thin as 0.4mm and as thick as 25mm. Molten glass, at approximately 1000ºC, is poured continuously from a furnace onto a shallow bath of molten tin. It floats on the tin, spreads out and forms a level surface. Thickness is controlled by the speed at which solidifying glass ribbon is drawn off from the bath. A start to finish process showing the melting or raw materials such as sand, gypsum, soda ash and limestone in the furnace, through to annealing and finally to the packaging and final inspection the glass emerges as a ‘fire’ polished product with virtually parallel surfaces.  A float plant operates non-stop for between 10-15 years.

Our partner, Andersen Windows, uses Cardinal Insulating Glass.  Cardinal’s float glass plants are designed to provide for the demands of our valued customers. Top of the line residential window manufacturers rely on a constant supply of high quality float glass. At Cardinal FG Company, such quality is what you can expect – our five U.S. FG facilities will provide it every time.

Did you know?

  • Float glass plants are enormous – over 350,000 square feet under each roof.
  • Each plant uses $500,000 of natural gas and $85,000 of electricity every month.
  • Plants run 24 hours a day, 365 days a year.
  • Each FG plant ships 35-40 trucks of glass every day, at almost 35,000 square feet per truck.
  • Glass is cut in sizes as small as 16” x 20” to as large as 130” x 204.”

These systems as well as the industry-leading inspection processes are the assurance that Cardinal glass will always meet or exceed specification and expectation. Great glass helps make great windows, so manufacturing superior float glass is always Cardinal’s stated goal.

Float Glass
Glass line

Float Glass Video