Abstract: Aqueous dispersion comprising silicon/titanium mixed oxide powder with a BET surface area of 5 to 500 m2/g which has been prepared by flame hydrolysis and has a titanium dioxide content of 0.5 to 20 wt. %, based on the powder, water and at least one pH-regulating substance which can be removed completely from the reaction mixture on heating, the aqueous dispersion having a solids content of between 40 and 80 wt. %. A green body produced therefrom with a green density of between 40 and 85%. A shaped glass article of optical quality with a coefficient of thermal expansion of not more than 0.5×10−6/K produced from the green body.

Abstract: An optical colored glass with a composition (in percent by weight based on oxide) of SiO2 30-75; K2O 5-35; TiO2 0-5; B2O3>4-17; ZnO 5-37; F 0.01-10 MI MIII Y2II 0.1-3, whereby MI=Cu+, Ag+, MIII=In3+, Ga3+, Al3+, YII=S2−, S2−, Te2−, as well as the use of this glass as a long-pass cutoff filter.

Abstract: The invention concerns an optical colored glass with a composition (in percent by weight based on oxide) of

Abstract: A layer which is obtained by thermal treatment from an aqueous dispersion applied to a substrate, the dispersion containing silicon/titanium mixed oxide powder prepared by flame hydrolysis. It is prepared by applying a dispersion which contains the silicon/titanium mixed oxide powder to a substrate and then sintering by using a thermal treatment. It can be used, for example, on materials with very low coefficients of expansion.

Abstract: The invention relates to a method for manufacturing optical glasses and coloured glasses with the aid of a fluid phase sintering process from a basic material encompassing at least SiO2 powder as well as additives for reducing the temperature of the fluid phase sintering and/or melting process encompassing the following steps:

Abstract: SiO2—TiO2 glasses having a low coefficient of thermal expansion are produced by a molding being produced that consists of SiO2 powder, SiO2—TiO2 powder or TiO2 powder and that contains by way of secondary component a titanium-containing component which is converted into amorphous TiO2.

Abstract: Method of manufacturing tubes in which a mixture of powdered tube material and a liquid binder is introduced into a tubular mold with a geometry corresponding to the geometry of the tube to be formed. The tubular mold is rotated about its longitudinal axis. The powder-binder mixture deposits on the inner wall of the tubular mold. The powder and the liquid are introduced into the tubular mold separately.

Abstract: Devices for and a method of manufacturing glass bodies, in which a porous green body is formed from the starting material for the glass body, being an aqueous suspension comprising a highly disperse solids content, which green body is then purified and sintered, and deposited by separating the phases of the suspension through electrophoresis, in such a manner that the solids content of the suspension is deposited on a porous deposition membrane having pores whose diameter is smaller than the average particle diameter of the solid particles present in the suspension, said membrane being arranged between the anode and the cathode, and the space between said membrane and the anode being filled with an electrically conducting liquid, a porous auxiliary membrane being arranged between and at a distance from the deposition membrane and the cathode, said auxiliary membrane having pores with a diameter which is smaller than the average particle diameter of the solid particles present in the suspension, and the space

Abstract: A method of producing glass bodies having regions with different optical refraction, including a basic body and a coating layer which is sintered onto the basic body, covers the basic body at least partially and is made of glass, which as it is doped, has an index of refraction differing from that of the glass of the basic body. The starting material for producing the cladding on the basis of pulverulent ceramic material is deformed into a self-supporting, unsintered porous green body, is dried and submitted to a cleaning procedure in a heated gas phase. The coating layer to be bonded onto the basic body is melted into glass in a subsequent combined doping/sintering procedure in a gas phase containing the doping agent at a temperature in the range from 1150.degree. to 1500.degree. C. and is sintered onto the basic body.

Abstract: A device of quartz glass for receiving or holding work pieces to be heated in a furnace, a region of the device projecting into the hot furnace zone having an arcuate part with a beginning of curvature and an end of curvature, which is enclosed by a vessel filled with an immersion liquid, heat radiation passed in the material of the device in a region located before the arcuate part due to total reflection being coupled out of the arcuate part and being coupled into the immersion liquid and a region of the device adjoining the arcuate part together with further device parts present at it being colder than the region located before the arcuate part.

Abstract: In a method of manufacturing glass bodies, in which a thixotropic suspension of SiO.sub.2 particles having a diameter in the range from 10 to 500 nm in a dispersing liquid is formed into a green body, after which the green body is purified and sintered, the suspension has a solid:dispersing liquid weight ratio of from 1:1 to 1:1.5, is passed through sieves having an aperture size in the range from 3 to 300 .mu.m under the action of sound or ultrasound, the sieved suspension is then concentrated by pumping off a part of the dispersing liquid under a vacuum and under the influence of sound or ultrasound, such that a solid:dispersing liquid weight ratio of about 1.3:1 is obtained, after which the concentrated suspension is introduced into a mould, heated to a temperature below the boiling point of the dispersing liquid to form a green body. The green body thus obtained is removed from the mould, cooled, and converted to a glass body.

Abstract: A method of drying ceramic green bodies, in which the green body is supported by a gas cushion and dried in a suspended position, while employing an arrangement comprising a filtering element which is adapted to the geometry of the green body to be dried, into which filtering element gas, preferably compressed air, can be introduced under pressure by a pipe supply. The gas issues from the filtering element's surface facing the green body to be dried through pore-like apertures which are envenly distributed over the whole surface where they form a gas cushion.

Abstract: A method of manufacturing glass or ceramic bodies in which an open-pore green body is formed from the starting material which is subjected to a purification process in a heated purification gas reacting with impurities present in the green body in such a manner that the device in which the green body to be purified is present is rinsed with flowing purification gas, is then sealed and subsequently evacuated until the gases present in the open-pore green bodies in the form of purification gas and gaseous reaction products have been removed, after which the purified green body is sintered, in which metallic impurities in the form of elements of the groups Ib, Va, VIa, VIIa, and/or VIII of the Periodic Table of Elements are converted into volatile complex compounds by a purification gas consisting of a carrier gas saturated with a sulphur-oxygen-halogen compound at a temperature in the range from 200.degree. to 500.degree. C.

Abstract: A method of manufacturing glass bodies, in which the starting material for the glass body, being an extrusion mass consisting of microdispersed SiO.sub.2 particles, a binder and a dispersing liquid, is used to form a porous green body by extrusion, which is subsequently dried, purified and sintered, the extrusion mass, which is shaped by the nozzle of an extruder, being extruded into a transfer vessel in which the extruded body is tempered towards the gelification point of the binder present in the extrusion mass, a liquid being contained in the transfer vessel, which cannot or substantially not be mixed with the dispersing liquid present in the extrusion mass, and which cannot be mixed with the binder present in the extrusion mass; and an arrangement for carrying out this method.

Abstract: A method of manufacturing glass bodies, in which the starting material for the glass body, being monodispersed SiO.sub.2 particles (quartz-glass powder), is used to form an open-pore green body which is subjected to a purification process in which the impurities present in the green body react with a purifying gas which is heated to a temperature in the range from 600 to 900.degree. C., after which the green body is sintered, in which a two-stage heating-purification step is used, such that in the first stage SiO.sub.2 particles are heated until they are dense-sintered, i.e. they have no more micropores, and in the second stage the homogeneous open-pore green body formed from the dense-sintered SiO.sub.2 particles is purified in a known manner in the purification gaseous atmosphere and subsequently sintered.

Abstract: A method of manufacturing rotationally symmetrical glass bodies. The starting material for the glass body is a thixotropic suspension consisting of powered glass in a liquid dispersing agent. The suspension is introduced into a hollow mold whose geometry corresponds to that of the glass body to be formed. The hollow mold is rotated about its longitudinal axis to deposit the suspension on the inner wall of the hollow mold. The after which the green body thus formed is purified and sintered. The green body is formed by heating the rotating mold and the suspension therein to a temperature below the boiling point of the dispersing liquid until cross-linking and solidification of the starting material is obtained. Thereafter, the green body can be removed from the hollow mold.

Abstract: A method of and arrangements for manufacturing glass bodies, in which method a thixotropic suspension, being the starting material for the glass body, is used to form a porous green body which is subsequently subjected to a purification step in a heated gaseous phase and then sintered to form a glass body, the starting material being homogenized and liquefied in a closed elastic mould by subjecting it to sound or ultrasonic, after which the liquid starting material is given the shape of the glass body to be formed and then solidified.

Abstract: A method of and arrangements for manufacturing glass bodies, in which the starting material for the glass body, being an anhydrous suspension having a microdispersed solids content, is used to form a porous green body which is subsequently purified and sintered, in which by separating the phases of an anhydrous suspension the green body is formed by means of electrophoresis on a deposition electrode whose shape corresponds to that of the glass body to be produced.

Abstract: Method and equipment for the manufacture of glass bodies with which a porous green body is formed from the starting material for the glass body in the form of an aqueous suspension with highly disperse solids content and this green body is then purified and sintered, the green body being deposited by separation of the phases of the suspension by electrophoresis.

Abstract: Method and equipment for the manufacture of glass bodies in which a porous green body is formed from the starting material for the glass body in the form of a thixotropic suspension, is dried, purified and then sintered, during which process the starting material is transformed into a state with minimum viscosity and homogenized by the introduction of mechanical forces, is poured in the low-viscosity state into a mould of hydrophobic material corresponding to the shape of the glass body to be manufactured and is dried in the mould until a shrinkage of approximately 10% is achieved and then, after removal from the mould, is subjected to further processing steps to produce the glass body.