Abstract: A glass article is composed of an aluminosilicate glass with at least one halogen with refining action in an amount ranging from 500 ppm to 8000 ppm and an Sn content of less than 500 ppm. The glass has less than 100 ppm As and less than 100 ppm Sb and the glass article has a thickness of less than 250 ?m.

Abstract: A glass article is composed of a glass having a demixing factor in respect of its hydrolytic resistance in a range from 0.10 to 1.65.

Abstract: The present invention relates generally to a process for producing glass products and to an apparatus suitable for the purpose. In the process, a melting apparatus is provided with a melting tank for producing a glass melt from glass raw materials and a top furnace. Part of the surface of the melting region of the melting apparatus is covered with the glass raw materials and at least a small portion of the surface of the melting region is uncovered. In addition, energy is introduced in such a way that a vertical temperature difference can be established, such that the temperature of the glass melt at the base is greater than the temperature of the atmosphere in the top furnace.

Abstract: A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free, antimony-free and tin-free with the exception of any unavoidable raw material impurities and at least one sulfate compound as a refining agent are used. The glass mixture and refining agent are melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1580° C. and an average melt residence time (t1) is set at t1>2 hours. A secondary refinement is carried out in a second region, an average melting temperature (T2) is set at T2>1660° C. and an average melt residence time (t2) is set at t2>1 hour, and the proportion of the SO3 resulting from decomposition of the sulfate is reduced to less than 0.002 wt. %.

Abstract: Methods for producing glass articles from glass melts are provided that include continuously introducing the glass melt into a stirrer vessel, stirring the glass melt in the stirrer vessel by at least one blade stirrer, continuously discharging the glass melt from the stirrer vessel, and shaping the glass melt to obtain the glass article. In some embodiments, the stirring is sufficient to draw the glass melt located at a surface of the stirrer vessel into the stirrer vessel so that a formation of a surface layer of the glass melt with a different composition from the composition of the glass melt introduced is prevented or at least minimized. In other embodiments, the stirring is sufficient so that the glass melt which is located at a surface in the stirrer vessel is not drawn into the stirrer vessel or is drawn in only insubstantially.

Abstract: A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free and antimony-free with the exception of any unavoidable raw material impurities and a sulfate compound and SnO2 as refining agents are used. The glass mixture is melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1560° C. and an average melt residence time (t1) is set at t1>2 hours. The proportion of SO3 resulting from the decomposition of the sulfate compound is reduced to less than 0.002 wt. % as the primary refinement is carried out. A secondary refinement is carried out in a second region of the melting tank, an average melting temperature (T2) is set at T2>1640° C. and an average melt residence time (t2) is set at t2>1 hour.

Abstract: A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free, antimony-free and tin-free with the exception of any unavoidable raw material impurities and at least one sulfate compound as a refining agent are used. The glass mixture and refining agent are melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1580° C. and an average melt residence time (t1) is set at t1>2 hours. A secondary refinement is carried out in a second region, an average melting temperature (T2) is set at T2>1660° C. and an average melt residence time (t2) is set at t2>1 hour, and the proportion of the SO3 resulting from decomposition of the sulfate is reduced to less than 0.002 wt. %.

Abstract: A method for melting inorganic materials, preferably glasses and glass-ceramics, in a melting unit with cooled walls is provided. The method includes selecting the temperature of at least one region of the melt is selected in such a way as to be in a range from Teff?20% to Teff+20%, where the temperature Teff is given by the temperature at which the energy consumption per unit weight of the material to be melted is at a minimum, with the throughput having been selected in such a way as to be suitably adapted to the required residence time.

Abstract: The device for homogenizing a glass melt has a melt receptacle and at least one stirring device arranged in the melt receptacle. Each stirring device consists of a stirrer shaft and stirrer blades extending toward an inside wall of the receptacle, which are configured to produce an axial feed of the glass melt in an inner stirring region between the stirrer shaft and front ends of the stirrer blades. The melt receptacle and the stirring device are configured so that a melt flow caused by the axial feed, which is opposite to the axial feed, seals a gap formed between the inside wall and the front ends of the stirrer blades, so that the glass melt cannot flow directly through the gap to a lower axial end of the inner stirring region. The invention also encompasses a method of homogenizing a glass melt.

Abstract: The invention relates to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device is disposed in a melt receptacle, which comprises a stirrer shaft and a plurality of stirrer blades, and wherein a gap (16) is formed between a wall region of the melt receptacle and the stirrer blades. According to the invention, the respective stirring device causes an axial feed action in an inner stirring region between the stirrer shaft and the stirrer blades in order to feed the melt in the stirring region along the stirrer shaft. A melt flow brought about by the axial feed action seals the gap against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device. According to the invention, a high level of homogenization can be achieved regardless of the entry point of the inhomogeneities.

Abstract: The device for homogenizing a glass melt has at least one stirring device, which includes a rotatable stirrer shaft (10) and stirrer paddles (11, 11?, 11?). The stirrer paddles are arranged at intervals from each other along the stirrer shaft to produce an essentially axially oriented conveying effect on the glass melt. To improve homogenization while simultaneously saving on noble metal material, the stirrer paddles (11, 11?, 11?) are each provided with a built-in element (11E). The built-in element (11E) has an edge (11K), which extends from the stirrer shaft (10) in a radial direction (R) along a rear paddle area (11B) with an edge length which is less by a specified distance (X) than the length (L) of the paddle area (11B) in a radial direction (R). These built-in elements provide a marked reduction in bubble formation.

Abstract: The invention relates to a method and to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device (10, 11) is disposed in the melt receptacle, which comprises a stirrer shaft (10) and a plurality of stirrer blades (11), and wherein a gap (16) is formed between a wall region of the melt receptacle (2) and the stirrer blades (11). According to the invention, the respective stirring device causes an axial feed action in an inner stirring region (12) between the stirrer shaft (10) and the stirrer blades (11) in order to feed the melt in the stirring region along the stirrer shaft (10). A melt flow brought about by the axial feed action seals the gap (16) against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device.

Abstract: The apparatus (300) for feeding, homogenizing, and conditioning a high viscosity glass melt for manufacturing display glass has a stirring device (110, 406), an upstream connecting part (100, 400) that connects the stirring device (110, 406) to an upstream melting and/or refining unit, and a downstream connecting part (120, 420) that connects the stirring device (110, 406) to a downstream forming or shaping device. Wall material and base material of the first and connecting parts and the stirring device (110, 406) coming in contact with the glass melt are made from a zirconium-dioxide-containing fire-resistant material containing a large amount, preferably more than 85 wt. %, of zirconium dioxide. A method of operating the apparatus to make display glass is also described.

Abstract: The process of producing a refined borosilicate glass includes preparing a glass batch with a composition in wt. % on the basis of oxide content of SiO2, 65-82; Al2O3, 2-8; B2O3, 5-13; MgO+CaO+SrO +BaO+ZnO, 0-7; ZrO2, 0-2; and Li2O+Na2O+K2O, 3-10; adding 0.05 wt. % to 0.6 wt. % of sulfate(s) expressed as SO3 to the glass batch as the refining agent; melting the glass batch including the refining agent to form melted glass; and then hot-shaping the borosilicate glass. The refining agent may also include from 0.01 wt. % to 0.6 wt. % of F? or from 0.015 wt. % to 0.6 wt. of Cl?. The sulfate is preferably an alkali metal and/or alkaline earth metal sulfate or sulfates.

Abstract: The invention relates to a method and a device for homogenizing a glass melt using at least one stirring means which is respectively arranged in a stirring vessel having an inlet (4) and an outlet (5), the respective stirring means having a plurality of stirrer blades (11, 20, 21) arranged spaced apart from one another along a common stirrer shaft (10). According to the invention, the stirring means and/or the device is configured in such a way that a net conveying effect of the stirring means overall from the inlet to the outlet is substantially imperceptible. The conveying effect of the stirring means overall from the inlet (4) to the outlet (5) is caused by the positioning of the stirring blades (11, 20, 21), by the geometric shape thereof and/or by the angular position of the stirring blades in the circumferential direction of the stirrer shaft (10).

Abstract: The invention relates to a method and to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device (10, 11) is disposed in the melt receptacle, which comprises a stirrer shaft (10) and a plurality of stirrer blades (11), and wherein a gap (16) is formed between a wall region of the melt receptacle (2) and the stirrer blades (11). According to the invention, the respective stirring device causes an axial feed action in an inner stirring region (12) between the stirrer shaft (10) and the stirrer blades (11) in order to feed the melt in the stirring region along the stirrer shaft (10). A melt flow brought about by the axial feed action seals the gap (16) against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device.

Abstract: The borosilicate glass of the invention is highly resistant to solarization, because it is free of CeO2. Also it contains 0.01 to 0.05 wt. % of Fe2O3 and 0.05 to 0.8 wt. % of TiO2. This borosilicate glass is especially advantageous for production of flash tubes, gas discharge lamps, and fluorescent tubes for brake lights and display backlights.

Abstract: A method for melting inorganic materials, preferably glasses and glass-ceramics, in a melting unit with cooled walls is provided. The method includes selecting the temperature of at least one region of the melt is selected in such a way as to be in a range from Teff?20% to Teff+20%, where the temperature Teff is given by the temperature at which the energy consumption per unit weight of the material to be melted is at a minimum, with the throughput having been selected in such a way as to be suitably adapted to the required residence time.

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 a borosilicate glass consisting of 0.01 0.05 wt. % Fe2O3 and 0.05 0.8 wt. % TiO2, which is highly resistant to solarization and which is especially suitable for use as backlight bulbs.