Abstract: A molding tool, a method, and an apparatus for hot forming of glass are provided that provide glass products used for pharmaceutical packaging. The molding tool includes a forming mandrel for reshaping at least a portion of a heated region of a glass precursor. The mandrel has a temperature-stable core material and an alloying element. The core material is made of precious metals, in particular of platinum group elements, and the further alloying element is made of one of tungsten, zirconium, rhodium, molybdenum, and rhenium.

Abstract: A molding tool, a method, and an apparatus for hot forming of glass are provided that provide glass products used for pharmaceutical packaging. The molding tool includes a forming mandrel for reshaping at least a portion of a heated region of a glass precursor. The mandrel has a temperature-stable core material and an alloying element. The core material is made of precious metals, in particular of platinum group elements, and the further alloying element is made of one of tungsten, zirconium, rhodium, molybdenum, and rhenium.

Abstract: A glass molding tool is provided that includes a forming mandrel, a method for forming glass, and to an apparatus for hot forming of glass. The glass products obtained in this way may be used as pharmaceutical packaging. The forming mandrel reshapes at least a portion of a heated region of a glass precursor. The mandrel includes a heat-resistant core material and a diffusion layer that is in contact with the glass precursor during reshaping.

Abstract: The regionally coated noble metal element used in glass production has an uncoated region for contacting a glass melt and an H2-impervious layer or an H2-impervious and O2-impervious layer on a side opposite from the uncoated region, which has a layer thickness ?1 mm, is heat-resistant, and is either liquid or solid. This layer is made from at least one glass or glass mixture, an at least partly crystallized glass or a ceramic material. The coated noble metal element can be a Danner channel, a Vello draw head, an A-draw head, a Vello needle, a drawdown needle, a discharge ring or a Danner blowpipe. A process for coating a noble metal element to produce the regionally coated noble metal element is also described.

Abstract: The method provides an improved quartz glass body, especially an improved quartz glass crucible for melting non-metals, non-ferrous metals, or silicon. The quartz glass body is made by a method in which a quartz glass-water mixture is supplied to a gypsum casting mold comprising an outer part and an inner part, dried in the gypsum mold, and put under an overpressure via a system of ducts in the form of textile tubes embedded in the mold during the drying. Later a resulting green glass body is removed from the mold. At least a portion of the shaping surfaces of the inner part of the gypsum mold are surfaces of a water-impermeable substance. The method provides a cast body with a reduced tendency to crack and with a smaller open porosity.

Abstract: The coated noble metal element used in glass manufacture, such as a noble metal pipe, has an uncoated side that contacts a glass melt and an H2-impervious layer or an H2-impervious and O2-impervious layer, which is provided on a side opposite from the uncoated side. The H2-impervious layer or H2-impervious and O2-impervious layer is heat-resistant and is liquid or solid. In one process for providing the layer on the noble metal element an empty space between the noble metal element and a ceramic insulating jacket is filled with a coating material, and then the coating material is melted so that it wets a surface of the noble metal element. The coating material can include glass cullet, crushed glass or glass powder or is a mixture of crushed glass and ground ceramic material.

Abstract: The present invention relates to a device and method for transporting, homogenizing or conditioning of glass melts or glass ceramic melts and is distinguished in that the new formation of bubbles after refining is at least reduced. The new formation of bubbles on the surfaces of components that are in contact with the melt is at least reduced by means of a layer having iridium as a material.

Abstract: The regionally coated noble metal element used in glass production has an uncoated region for contacting a glass melt and an H2-impervious layer or an H2-impervious and O2-impervious layer on a side opposite from the uncoated region, which has a layer thickness?1 mm, is heat-resistant, liquid or solid. This layer is made from at least one glass or glass mixture, an at least partly crystallized glass or a ceramic material. The coated noble metal element can be a Danner channel, a Vello draw head, an A-draw head, a Vello needle, a drawdown needle, a discharge ring or a Danner blowpipe. A process for coating a noble metal element to produce the regionally coated noble metal element is also described.

Abstract: The invention includes an improved quartz glass body, especially an improved quartz glass crucible for melting non-metals, non-ferrous metals, or silicon, and a method and casting mold for making it The quartz glass body is made by a method in which a quartz glass-water mixture is supplied to a casting mold comprising an outer part and an inner part, dried in the mold, and put under an overpressure during the drying. Later a resulting green glass body is removed from the mold. At least a portion of the shaping surfaces of the inner part of the mold are surfaces of a water-impermeable substance. The method provides a cast body with a reduced tendency to crack and with a smaller open porosity.

Abstract: The coated noble metal element used in glass manufacture, such as a noble metal pipe, has an uncoated side that contacts a glass melt and an H2-impervious layer or an H2-impervious and O2-impervious layer, which is provided on a side opposite from the uncoated side. The H2-impervious layer or H2-impervious and O2-impervious layer is heat-resistant and is liquid or solid. In one process for providing the layer on the noble metal element an empty space between the noble metal element and a ceramic insulating jacket is filled with a coating material, and then the coating material is melted so that it wets a surface of the noble metal element. The coating material can include glass cullet, crushed glass or glass powder or is a mixture of crushed glass and ground ceramic material.

Abstract: The regionally coated noble metal element for use in glass production has an uncoated region for contacting a glass melt and a side opposite from the uncoated region is provided with an H2-impervious layer or an H2-impervious and O2-impervious layer. The H2-impervious layer or H2-impervious and O2-impervious layer has a thickness greater than or equal to 1 mm, is heat-resistant, liquid, or solid. This layer is made from at least one partly or completely crystallized glass or a glass mixture or a ceramic material. Processes for coating the noble metal element are also described.

Abstract: The apparatus for reduced-pressure refining of a glass melt includes a refining bank formed so that a reduced pressure is generated by a glass flow in it. The refining bank has a component, which is made from a refractory metal or refractory alloy acting as glass-contact material. The refractory metal or alloy contains molybdenum, tungsten, tantalum, and/or hafnium. The device of the present invention includes a protective gas reservoir for a protective gas and an automatically operating valve connecting the reservoir with the refining bank so that an inner side of the component that would otherwise be exposed when a pressure rise or a falling glass melt column occurs is protected from oxidation by the protective gas. A process for using the device during refining of the glass melt is also part of the invention.

Abstract: The invention relates to a method and a device for refining a glass melt, using negative-pressure apparatus. According to the invention, the glass melt is fed to a refining bench by means of an uptake pipe and is discharged from the refining bench by means of a downpipe, a negative pressure being created over the flow of glass in the refining bench. The invention is characterised in that the uptake pipe and/or the downpipe and/or the refining bench has/have at least one component consisting of at least one refractory metal and/or of a refractory metal alloy as the glass contact material.

Abstract: The invention relates to a coated metal element used for producing glass, said element having a coating on the opposite side to the glass melt that is impermeable to H2, or to H2 and O2. The invention also relates to a method for coating metal elements used for producing a glass melt and glass, according to which an insulating casing is applied to the side of the metal element to be coated, in such a way that a cavity is formed between the surface to be coated and the insulating casing, the cavity is filled with the coating material and said material is melted at a sufficiently high temperature.