Glass

How is glass Made?

Glass for architectural applications must start off flat and uniform. Annealed glass is basically how glass is born. Silica is combined with other materials like limestone and soda ash. The raw materials are melted. Then the molten glass is floated on molten metal, typically tin for it’s low melting point. Then the glass is slowly and uniformly cooled in a controlled environment, or annealed. This process ensures a uniform thickness. The width of the ribbon of molten glass spilling onto tin will determine the width of the sheet. The length will be the interval at which the glass is cut. The speed of the float line will determine the glass thickness.


You may also hear this type of glass referred to as sheet glass, flat glass, plate glass or float glass. Float glass is the foundational product for most glass used in construction. Annealed glass can then be cut and fabricated. There are about 40 manufacturers with 230 float glass plants worldwide. Just a couple of plants are in the western United States. Float glass is then shipped to fabrication plants. A lot of what comes into CA is from China.