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Float glass is manufactured by melting sand. Other ingredients
such as soda ash, limestone and salt cake are added
to lower the melting temperature of silica and promote optical
clarity of the finished glass product. Mixed batch of
above materials is heated to a temperature of about 1550oC
and formed into large flat sheets by floating molten glass
on molten tin thus giving it precise flatness and transparency.
The float process enabled a number of new technologies
and product developments. For the first time,
uniform, high quality float glass could be made in a
variety of thick nesses, to address safety, security
or noise reduction concerns while still meeting the
highest aesthetic standards. The float process made
it easy to vary the composition of the molten glass
to make products for special applications such as
tinted glass.