Abstract: The invention relates to a method for producing aluminosilicate glass that is devoid of alkali and that has a B2O3 content of between 0 and <5 wt.-% and a BaO content in excess of 5.5 wt.-%. Said method is characterised by the addition of between 0.05 wt.-% and 1.0 wt.-% SnO2 during the preparation of the mixture.

Abstract: The process of the invention produces alkali-free aluminosilicate glass having an Al2O3-content of more than 12% by weight with the addition of from 0.005% by weight to 0.6% by weight of sulfate for batch formulation.

Abstract: The invention relates to lead- and cadmium-free glass for glazing, enamelling and decorating glasses or glass-ceramics which have a low coefficient of thermal expansion of less than 2×10−6/K, having the composition (in % by weight) 0-6 Li2O, 0-5 Na2O, 0 to less than 2 K2O, where the sum Li2O+K2+Na2O is between 2 and 12, 0-4 MgO, 0-4 CaO, 0-4 SrO, 0-1 BaO, 0-4 ZnO, 3 to less than 10 Al2O3, 13-23 B2O3, 50-65 SiO2, 0-4 TiO2, 0-4 ZrO2 and 0-4 F, as replacement for oxygen and containing up to 30% by weight of a pigment which is resistant at the firing temperature, where the glass is suitable for glazing, enamelling and decoration in both primary and secondary firing, and both the full-area and sparse glaze, enamel or decoration layers have low abrasion susceptibility after firing, and it relates to processes for the production of a glass-ceramic coated therewith.

Abstract: There is disclosed a stove, with a smooth-top cooktop, for cooking food, the stove comprising: a stove body; a smooth-top cooktop to cook food thereon; and at least one heat source disposed adjacent to a cooking surface of said cooktop. The cooktop comprises glass ceramic with an upper layer and an inner layer, with the upper layer comprising a different glass ceramic material than the inner layer. The upper layer is configured to minimize surface defects such as fissures, cracks, pits, and pores. The inner layer is configured to provide resistance to impact to the upper layer from cooking utensils being dropped onto the upper layer of the smooth-top cooktop, and at least the inner layer of the glass ceramic being configured to obscure visibility of the at least one heat source, through the upper layer of the glass ceramic.

Abstract: There is disclosed a stove, with a smooth-top cooktop, for cooking food, the stove comprising: a stove body; a smooth-top cooktop to cook food thereon; and at least one heat source disposed adjacent to a cooking surface of said cooktop. The cooktop comprises glass ceramic with an upper layer and an inner layer, with the upper layer comprising a different glass ceramic material than the inner layer. The upper layer is configured to minimize surface defects such as fissures, cracks, pits, and pores. The inner layer is configured to provide resistance to impact to the upper layer from cooking utensils being dropped onto the upper layer of the smooth-top cooktop, and at least the inner layer of the glass ceramic being configured to obscure visibility of the at least one heat source, through the upper layer of the glass ceramic.

Abstract: This invention relates to a flat float glass that can be prestressed or transformed into a glass ceramic with high quartz mixed crystals or keatite mixed crystals. To eliminate undesirable surface defects during floating and to achieve superior characteristics of the glass or of he glass ceramic, in particular with regard to a low coefficient of thermal expansion and high light transmittance, the glass has a concentration of less than 300 ppb Pt, less than 30 ppb Rh, less than 1.5 wt. % ZnO and less than 1 wt. % SnO2, and is refined during melting without the use of the conventional fining agents arsenic oxide and/or antimony oxide.

Abstract: The present invention generally relates to a method of making halogen lamps and halogen lamp bulbs, as well as other analogous lamps and objects. The present invention also relates to apparatus used in a method of making halogen lamps and halogen lamp bulbs, as well as other analogous lamps and objects. The method minimizes contamination in the body of the glass and minimizes reaction of lamp halogen with the interior of a halogen lamp.

Abstract: The invention is directed to an aluminosilicate glass containing alkaline earth metals for lamp bulbs which have molybdenum components and bulb temperatures of greater than 650.degree. C. The glass has a composition in percent by weight on oxide basis as follows: SiO.sub.2 >58-62; Al.sub.2 O.sub.3 15-17.5; B.sub.2 O.sub.3 0.2-0.7; MgO 0-<1; CaO 5.5-14; SrO 0-8; BaO 6-10; ZrO 0.05-1.0; CeO.sub.2 0-0.3; TiO.sub.2 0-0.5; Br.sup.- 0-0.6 where .SIGMA. RO 21-24; (MgO+CaO+SrO)/BaO 1.45-1.75; and an alkali metal content of <0.03% by weight and a water content of <0.02% by weight.

Abstract: The invention is directed to a method of producing a chemically pretensioned glass body. In the method, a glass body is provided having a composition in percent by weight on oxide basis: SiO.sub.2 70-85; B.sub.2 O.sub.3 8-15; Na.sub.2 O 1-5; K.sub.2 O 1-<5; Al.sub.2 O.sub.3 1-5; MgO 0-3; SrO+BaO 0-2; CaO 0-3; ZnO 0-3; with CaO+ZnO 2-6; and, ZrO.sub.2 0-3.5. The glass body is placed in an ion exchange salt bath containing at least 90% by weight of potassium salts. The salt bath is maintained at a temperature below the transformation point Tg of the glass defined by the glass composition for a duration of at least 2.0 hr causing potassium ions from the salt bath to migrate into the surface region of the glass body to thereby produce the chemically pretensioned glass body.

Abstract: Process for the production of decorative glass ceramic articles, the design being sunk entirely or partially into the surface of the glass ceramic, wherein the surface, to be decorated, of the not-yet ceramed base glass is connected as the anode of the region of its glass transition temperature Tg up to Tg+100.degree. C. and a current is allowed to flow evoking an alteration of the surface of the base glass, and wherein the current is permitted to flow until the surface has been altered to a desired depth.