Abstract:
The apparatus for supporting a glass body is made by a method including the following steps: putting carbon-containing fibers in an axially parallel arrangement and tightly packing them; twisting the resulting tightly packed carbon-containing fiber bundle to form a carbon-containing fiber rope piece and fixing it in a twisted state; then pyrolyzing the resulting carbon-containing fiber rope piece, soaking the pyrolyzed carbon-containing fiber rope piece in a silicon-containing fluid and ceramicizing the carbon-containing fiber rope piece. The supporting apparatus formed by this method includes a gas-permeable body, which has channels or passages through which a gas, such as air, can pass. The channels are inclined at their outlet ends on a gas outlet surface of the gas-permeable body.
Abstract:
The invention relates to a method for the hot shaping of molten gobs on a mold base by interposing a gas bed, comprising the following method steps. According to the invention such a method comprises the following method steps: a mold base made of open-pore mold material is produced; the supporting surface of the mold base is coated permanently with a glass contact material; such a coating material is chosen or the coating is arranged in such a way that the layer comprises open pores after its application which allow a gas-conductive connection between the lower side and the upper side of the layer; the mold base is charged with a gas in order to produce a gas bed on the upper side of the layer.
Abstract:
The silicate glass has a composition (in % by weight, based on oxide) of SiO2, 54-72; Al2O3, 0.5-7; ZrO2, >10- 5-24; La2O3, 0-6; and TiO2, 0-4. The glass has at least 0.6% by weight of La2O3 or at least 0.1% by weight TiO2. The glass is in hydrolytic glass 1, acid class 3 or better, preferably acid class 1, and lye class 1. It has a glass transition temperature (Tg) of at least 640° C., a thermal expansion coefficient (&agr;20/30O) of 4.1×10−6 to 8.0×10−6/K, a refractive index (nd) of 1.53 to 1.63, an Abbé number (&ngr;d) of 47 to 66 and a negative anomalous partial dispersion in a blue spectral region (&Dgr;Pg,F) of up to −0.0130.
Abstract:
The method of continuously producing flat glass includes rolling a fluid glass sheet between upper and lower shaping rollers to shape and calibrate the glass sheet, generating a respective gas cushion between the fluid glass sheet and each shaping roller from a liquid, controlling the pressure of the gas cushion between the fluid glass sheet and the upper shaping roller to completely prevent contact of the glass sheet with the upper shaping roller, controlling the pressure of the gas cushion between the fluid glass sheet and the lower shaping roller to form a linear contact area between the fluid glass sheet and the lower shaping roller and controlling the contact area width according to speed and viscosity of the glass sheet in order to transport it without slipping and reduce cooling path length.
Abstract:
For permitting temperature manipulation of a melt even at a conductivity below 10−1 Ω−1 cm−1 and thus permitting refining of the melt at temperatures about 1700° C., the invention provides a method and a device for temperature manipulation of a melt (16), in particular in a refiner unit. The melt (16) is heated at least by ohmic resistance heating with at least two electrodes (4) that are arranged in the melt (16). At least a part of the melt (16) is cooled. The device (1) for temperature manipulation, refining, purification and homogenisation of a melt (16) comprises at least one arrangement for accommodating melt material (36, 16), defining an inner chamber, and at least two electrodes (4) for ohmic resistance heating of the melt (16). The electrodes (4) project into the inner chamber of the arrangement, in particular of a vessel (2).
Abstract:
For permitting temperature manipulation of a melt even at a conductivity below 10−1 Ω−1 cm−1 and thus permitting refining of the melt at temperatures about 1700° C., the invention provides a method and a device for temperature manipulation of a melt (16), in particular in a refiner unit. The melt (16) is heated at least by ohmic resistance heating with at least two electrodes (4) that are arranged in the melt (16). At least a part of the melt (16) is cooled. The device (1) for temperature manipulation, refining, purification and homogenisation of a melt (16) comprises at least one arrangement for accommodating melt material (36, 16), defining an inner chamber, and at least two electrodes (4) for ohmic resistance heating of the melt (16). The electrodes (4) project into the inner chamber of the arrangement, in particular of a vessel (2).
Abstract:
An apparatus for press-forming a molten gob made of meltable material, especially of glass or glass ceramics, into a body of specific shape with compression moulds which form with each other a form cavity for receiving the gob. The compression moulds consist at least in the zone of the forming surfaces of an open-pore material and the compression moulds are connected to a pressure gas source in order to produce a gas stream which emerges from the forming surfaces. The open-pore material of the forming surfaces the pores close to the forming surfaces are smaller than the pores remote from the forming surfaces.
Abstract:
The invention relates to a method of producing glass-ceramic parts and/or glass parts by deformation of a glass-ceramic blank and/or glass blank. The invention is characterized in that forming is carried out using infrared radiation.
Abstract:
A method for making flat glass of good quality by rolling is described, in which a gas cushion is formed between the upper shaping roller and the glass sheet and contact between the lower shaping roller and the glass sheet is limited to a width of from 5 to 30 mm. The resulting flat glass has an upper surface quality that is nearly that of a fire-polished glass surface, while the lower surface has an improved quality that is better than that obtained by the prior art method. Furthermore it is advantageous that the method does not require an increase in the length of the cooling path following the rollers.
Abstract:
The silicate glass has a composition (in % by weight, based on oxide) of SiO2, 54-72; Al2O3, 0.5-7; ZrO2, 10-20; B2O3, 0- 5-24; La2O3, 0-5; and TiO2, 0-4. The glass also contains at least 0.6 percent by weight of La2O3 or at least 0.1 percent by weight TiO2. The glass has a hydrolytic resistance in hydrolytic glass 1, an acid resistance in acid class 3 or better, preferably acid class 1, a caustic lye resistance in lye class 1, a glass transition temperature (Tg) of at least 650° C., a thermal expansion coefficient (&agr;20/300) of 4.1×10−6 to 7.4×10−6/K, a refractive index (nd) of 1.53 to 1.63, an Abbé number (&ngr;d) of 48 to 58 and a negative anomalous partial dispersion in a blue spectral region (&Dgr;Pg,F) of up to −0.0130.