Abstract: A method of making glass products includes: heating material to obtain a glass melt; heating the glass melt in a melting tank having a melting tank bottom, the glass melt having a melt volume, a melt surface, and a viscosity of 102 dPas at a temperature above 1580° C. The glass melt is heated such that at least some of the glass melt has a viscosity of 102.5 dPas or less. An amount of thermal energy introduced directly into the melt volume is more than 60% of a total amount of thermal energy introduced into the glass melt. A maximum difference between a temperature at a location on the melt surface and a temperature at a location at the melting tank bottom vertically underneath the location on the melt surface is such that a difference in glass melt densities is less than 0.05 g/cm3 per meter distance between the locations.

Abstract: A glass having a good hydrolytic resistance and alkali resistance is defined by a targeted combination of stoichiometric glasses, including glasses also existing as crystals in the same stoichiometry and whose properties can be assumed as being very similar due to the identical topology of the structural units for glass and crystal, respectively. A process of producing the glasses is also provided.

Abstract: A glass includes a composition which is characterized by the following constituent phases of the glass: 20-80 mol % silicon dioxide; 0-40 mol % wollastonite; 0-30 mol % cordierite; 0-40 mol % anorthite; 0-40 mol % strontium-feldspar; 0-20 mol % celsian; 0-40 mol % hardystonite; 0-10 mol % titanite; and 0-15 mol % gittinsite. Where the composition is specified in mol % relative to oxides, the glass contains less than 11.5 mol % Al2O3 and less than 5000 ppm (molar, relative to the oxides) of each of B2O3, Li2O, Na2O, K2O, Rb2O and Cs2O. A calculated value for the removal rate according to ISO 695 is not more than 81.9 mg/(dm2 3 h) and a calculated value for the removal rate in acid according to DIN12116 is less than 3.5 mg(dm2 6 h).

Abstract: A glass, a glass article made of the glass as well as uses and production methods are disclosed. The glass constituents are selected such that excellent scratch resistance and impact strength are provided. The glass has a composition characterized by the following constituent phases: 15-60 mol % reedmergnerite; 20-60 mol % albite; 0-20 mol % nepheline; 0-20 mol % orthoclase; 0-20 mol % parakeldyshite; 0-20 mol % narsarsukite; 0.1-30 mol % disodium zinc silicate; 0-4 mol % diboron trioxide; 0-20 mol % cordierite; and 0-20 mol % danburite. A quotient of a coefficient of thermal expansion of the glass multiplied by 1000 (in ppm/K) and the product of a pH value and a removal rate in alkaline environment (in mg/(dm23h)) according to ISO 695 is at least 8 and the removal rate in alkaline environment according to ISO 695 is at most 115 mg/(dm23h).

Abstract: The present invention relates to glasses, such as e.g. thin or thinnest glasses, but also to glasses for the production of tubular glass, carpules and syringes as well as other pharmaceutical vessels. The glasses are characterized by a high chemical prestressability (tem-perability) with very well alkali, hydrolytic and/or acid resistance as well as an advantageous coefficient of thermal expansion. The glass has a composition characterized by the following constituent phases: 0-60 mol % reedmergnerite; 20-60 mol % albite; 0-30 mol % orthoclase; 0-20 mol % natrosilite; 0-20 mol % sodium metasilicate; 0-20 mol % parakeldyshite; 0-20 mol % narsarsukite; 0-20 mol % disodium zinc silicate; 0-21 mol % cordierite; and 0-20 mol % danburite. A quotient of a coefficient of thermal expansion of the glass multiplied by 1000 (in ppm/K) and the product of a pH value and a removal rate in alkaline environment (in mg/(dm23h)) according to ISO 695 is at least 9.0.

Abstract: A glass is described, a glass article made of the glass as well as uses and production methods. The glass constituents are selected such that it results in excellent chemical stability and ion ex-changeability. The glass has a composition characterized by the following glass constituent phases: 0-35 mol % reedmergnerite; 10-60 mol % albite; 3.5-25 mol % orthoclase; 0-40 mol % natrosilite; 0-20 mol % parakeldyshite; 0-20 mol % narsarsukite; 0-35 mol % disodium zinc silicate; 0-35 mol % silicon dioxide; 0-30 mol % cordierite; and 0-20 mol % danburite. A quotient of a coefficient of thermal expansion of the glass multiplied by 1000 (in ppm/K) and the product of a pH value and a removal rate in alkaline environment (in mg/(dm23h)) according to ISO 695 is at least 9.25.

Abstract: A glass having a good hydrolytic resistance and alkali resistance is defined by a targeted combination of stoichiometric glasses, including glasses also existing as crystals in the same stoichiometry and whose properties can be assumed as being very similar due to the identical topology of the structural units for glass and crystal, respectively. A process of producing the glasses is also provided.

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 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 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 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.