Abstract: A method of and arrangements for manufacturing glass bodies, in which the starting material for the glass body, being a 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 the suspension in an arrangement in which a pressure difference can be built up, the green body is deposited on a porous membrane whose shape corresponds to that of the glass body to be produced, the pores of the membrane having a diameter in the range from 1 to 500 times the average particle diameter of the solids content of the suspension.

Abstract: Method and equipment for the manufacture of glass bodies wherein a porous green body is formed by extrusion from the starting material for the glass body in the form of a thixotropic suspension and this green body is then purified and sintered, during which process the starting material is brought in a state of minimum viscosity into an extruding press closed at its outlet end, is heated in the extruding press to a temperature below the boiling point of the dispersing liquid and then, after the extruding press is opened, is extruded into a green body of dimensionally stable shape by means of the die of the extruding press.

Abstract: A method of manufacturing glass bodies, in which the starting material for the glass body, in the form of microdispersed SiO.sub.2 particles, is used to form an open-pore green body which is subjected to a cyclic 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.degree. to 900.degree. C., after which the green body is sintered; in each cycle of the said process, the arrangement holding the green body to be purified being flushed and subsequently evacuated.

Abstract: A method for the manufacture of glass bodies, in which a thixotropic suspension, being the starting material for the glass body, is used to form a porous green body which is subsequently purified and sintered, the starting material being liquefied in a mould by subjecting it to mechanical forces, and subsequently freeing it of the influence of the said forces, after which it solidifies again to form a green body.

Abstract: A layer consisting of a grinding medium such as corundum, SiC, emery or quartz sand is provided in a mould for the production of glass objects. A portion of this layer sticks to the glass work piece formed in this mould and is used for a subsequent surface processing procedure.

Abstract: An electrophotographic recording material having a porous layer of photoconductor-binder, particularly with crystalline tetragonal lead monoxide as the photoconductor, is provided between an electrically conductive layer and a dielectric foil, said pores of the layer of photoconductor-binder, prior to providing the foil, being filled with a high-ohmic dielectric liquid to wet both the layer of photoconductor-binder and the foil. Preferably, the pores of the layer are filled with tetramethyl tin as the photoconductor-binder. As a result of this, the use of an adhesive between the foil and the layer of photoconductor-binder may be omitted. A large porosity and hence a great sensitivity of the layer of photoconductor-binder are maintained.