Building Products Processes
Coated Glass
Glass is coated on-line – in the float process – or off-line in a secondary process. Coating can be deposited on-line as the ribbon of glass is being formed in the float glass bath. The technology uses chemical vapour deposition to apply a microscopically thin coating on the glass at a temperature of about 600ºC. Pilkington Activ™ self-cleaning glass is an on-line coated product. Off-line processes use a vacuum coating technology called sputtering. A ‘target’ material is bombarded to produce atoms that are deposited on the glass.
Coated glass is used in buildings and vehicles to control heat and light transmission.
Demand for specialist coated glass is growing with the development of the solar power generation industry.
Rolled and Wired Glass
Rolled glass is made by flowing a ribbon of molten glass between rollers at a temperature of 900ºC. Patterns on the metal rollers are imparted to the glass as it passes through them. Wired glass is made in the same process.
Tinted Glass
Extra ingredients are added to the raw materials of glass at the melting stage to produce tinted products. Cobalt and nickel tint glass grey. Ferrous oxide tints glass blue, while ferric iron generates a yellow tint – both together tint the glass green. Tinted glass is used in buildings and vehicles to control heat and light transmission.
Silvering
Float glass is made into mirrors in a process that deposits a thin film of high purity silver on one surface of the glass. This is then protected with a heat-setting paint.