Abstract: Glazing, thermally tempered to required standards, are produced more readily by tempering panes having a high coefficient of thermal expansion (greater than 93×10−7 per degree Centigrade) and for a low Fracture Toughness (less than 0.72 MPam1/2). Use of glasses selected according to the invention enables thin glazings (especially glazings less than 3 mm thick) to be tempered to automotive standard with improved yields using conventional tempering methods, and thicker glazings to be tempered at lower quench pressure than required hitherto. Suitable glasses include glasses comprising, in percentages by weight, 64 to 75%, SiO2, 0 to 5% Al2O3, 0 to 5% B2O3, 9 to 16% alkaline earth metal oxide other than MgO, 0 to 2% MgO, 15 to 18% alkali metal oxide and at least 0.05% total iron (calculated as Fe2O3).

Abstract: Glazing, thermally tempered to required standards, are produced more readily by tempering panes having a high coefficient of thermal expansion (greater than 93×10−7 per degree Centigrade) and for a low Fracture Toughness (less than 0.72 MPam½). Use of glasses selected according to the invention enables thin glazings (especially glazings less than 3 mm thick) to be tempered to automotive standard with improved yields using conventional tempering methods, and thicker glazings to be tempered at lower quench pressure than required hitherto. Suitable glasses include glasses comprising, in percentages by weight, 64 to 75% SiO2, 0 to 5% Al2O3, 0 to 5% B2O3, 9 to 16% alkaline earth metal oxide other than MgO, 0 to 2% MgO, 15 to 18% alkali mental oxide and at least 0.

Abstract: The invention relates to the press bending and tempering of glass sheets, especially for use as glazings in vehicles. When the press bending system is not located in a heated environment such as a furnace, it is important to maintain the glass sheets at a sufficiently high temperature for an adequate degree of temper to be achieved on quenching the sheet. The present invention provides a method of bending and tempering a thin glass sheet comprising pressing the substantially horizontal sheet between moulds having opposed complementary shaping surfaces, at least one of the surfaces being heated, and subsequently quenching the surfaces of the sheet characterised in that the heated shaping surface is maintained at a temperature in the range from 200.degree. C. to 350.degree. C.

Abstract: Glass sheets are press bent and tempered, especially for use as glazings in vehicles. Such glazings are required to be accurately bent to a complex shape while meeting high standards of optical quality and fracture safety at an acceptable cost. A method of bending and tempering a glass sheet is provided comprising heating the sheet in a furnace, including heating at least one portion of the sheet to a higher temperature than another portion, conveying the sheet out of the furnace and into a press bending station, shaping the sheet by pressing it between opposed complementary upper and lower press members, at least one of the members being internally heated, transferring the bent glass sheet onto a shuttle carrier ring conforming to the periphery of the sheet, and tempering the sheet while supported on the carrier ring. A corresponding apparatus is also described.