Flachglas

Flachglas, or flat glass, is a sheet of glass produced for architectural and industrial glazing. It is typically manufactured by the float glass process, in which molten glass is floated on a bed of molten tin to produce surfaces with high optical quality and uniform thickness. After cooling, the glass can be further processed or finished to meet specific requirements.

Common variants include annealed glass, tempered glass (heat-treated for higher strength), laminated glass (two or more sheets with an interlayer, usually PVB), and insulated glazing units (IGUs) consisting of two or more panes separated by a spacer and filled with air or gas to reduce heat transfer. Glass can be coated for functional performance, such as low-emissivity (low-E) coatings to reduce heat transfer or solar-control coatings that modify visible light and solar gain. Coatings may be applied as soft coats or hard coats, influencing durability and performance. Finishing processes can include edge grinding, tempering, lamination, and intricate surface treatments.

Flachglas is used in windows, facades, doors, skylights, interior partitions, and other glazing applications. Safety variants, including tempered and laminated glass, are employed where increased strength, impact resistance, or controlled breakage is required. The selection of glass type, coatings, and IGU construction affects thermal performance, light transmittance, acoustic insulation, and solar control, as well as structural performance and safety.

Industry standards for flat glass in Europe cover product quality, testing, and performance. Common references include EN 572 for glass products and EN 1279 for insulating glazing units, along with related safety and performance standards. The development of the float process in the mid-20th century enabled continuous production of high-quality flat glass and underpins modern glazing systems.