Abstract: A method and device are described for the production of foams from two-component reactive mixtures using carbon dioxide as expanding agent, by mixing at least one of the reactive components with carbon dioxide under pressure. That mixture is then mixed with the other reactive component(s) to form a foamable reactive mixture, which is expanded and cured to form the final product. The foamable reactive mixture is expanded to ambient pressure through at least one fine-meshed screen (21a, 21b, 21c).

Abstract: A process and a device are described for the production of polyurethane foam by application of a froth onto the conveyor belt of a block-foam installation, whereby the froth is applied onto the lower conveyor belt in a free, substantially vertical fall and flowing of the froth contrary to the direction of movement of the conveyor belt is prevented by a stationary, substantially vertical barrier arranged transversely on the conveyor belt.

Abstract: A process for the manufacture of polyurethane foam moldings is described wherein carbon dioxide physically dissolved under pressure is used as the blowing agent and a pressure is maintained in the mold cavity during the introduction of the polyurethane reactive mixture so as to prevent the complete release of the dissolved carbon dioxide.

Abstract: For the expansion of a liquid containing gas under pressure in dissolved form, it is proposed that the liquid be passed with expansion through an extended flow channel with a small cross-sectional measurement with generation of high rates of shear. The velocity of the liquid is then reduced prior to the foaming.

Abstract: An apparatus for preparing flowable reaction mixtures from at least two flowable reactants in which the components are injected into a mixing chamber by means of injection nozzles, the force of the reactant acting upon the nozzle needle is at least substantially compensated to avoid impairing the mixing ratio during a change-over of the nozzle needle. The rear end of the nozzle needle is provided with a chamber communicating with the component supply line.

Abstract: A method and device are described for the production of foams from two-component reactive mixtures using carbon dioxide as expanding agent, by mixing at least one of the reactive components with carbon dioxide under pressure. That mixture is then mixed with the other reactive component(s) to form a foamable reactive mixture, which is expanded and cured to form the final product. The foamable reactive mixture is expanded to ambient pressure through at least one fine-meshed screen (21a, 21b, 21c).

Abstract: When pulverising polyurethane, polyurea and/or polyurethane/polyurea materials in a roller mill with at least two rollers (2,3) rotating at different circumferential speeds, a very economical method of operation is achieved by returning the coarse fraction falling freely out of the roll slit (4) to the roll slit (4) and stripping the fine material adhering to the roller (3) with the higher circumferential speed and discharging it separately from the coarse fraction.

Abstract: A valve for use in introducing a foamable reactive mixture into a cavity, with the valve being of such size that it can be positioned within the cavity and when so-positioned is in contact with at least one of the walls of the cavity, with the valve including:a) two essentially rotationally symmetrical coaxial cages, with said coaxial cages being spaced from each other, with the inner cage;i) having an axial opening for the introduction of the reactive mixture and at least two radial openings for the passage of the reactive mixture into the annular space formed between the inner and the outer cage; ii) having a ball, capable of moving freely within said inner cage and capable of closing the inlet opening following completion of the introduction of the reactive mixture; iii) having a convex surface opposite said inlet opening, with said convex surface being directed inward, so that during the introduction of the reactive mixture the ball assumes a position outside the inner cage axis; andb) with said outer cag

Abstract: For the expansion of a liquid containing gas under pressure in dissolved form, it is proposed that the liquid be passed with expansion through an extended flow channel with a small cross-sectional measurement with generation of high rates of shear. The velocity of the liquid is then reduced prior to the foaming.

Abstract: A process and device for foaming casings, particularly refrigerator casings, with a blowing agent which can form an explosive mixture with atmospheric oxygen during evaporation which reduce the risk of explosion by introducing inert gas into the space in which the foam is to be formed by means of a servo-controlled inlet valve.

Abstract: A process for the simultaneous, constantly available provision of amounts of energy and/or signal-transmission media to a plurality of workstations circulating in the shape of an oval is described. A supply line, connected to all the workstations, is circulated with workstations. Energy and/or signal-transmissions are fed through a trailing cable which is connected to a rotary linkage which is capable of travelling back and forth on a rail within the oval in the longitudinal direction of the oval and from the rotary linkage to the supply line.

Abstract: The invention is directed to an apparatus for the production of polyurethane moldings endless in one dimension using at least two alternately operated mixheads for the reactive polyurethane components. Material which has been correctly conditioned by circulation of the reactive components through the mixhead not in operation arrives at that mixhead at least before it is put into operation and the components are delivered by units which are common to the mixheads, but independent of one another in regard to "mixing" and "conditioning".

Abstract: A method and apparatus for continuously dispersing fine particle-sized solids in liquids by a continuous process, in which a constant stream of liquid is fed into a mixing apparatus and fine-particle-sized solids are metered into the mixing apparatus by means of a metering screw as a function of the pressure prevailing in the mixing apparatus. The solids conveyed by the metering screw are supplied from an intermediate vacuum tank with a controlled filler level.

Abstract: The invention relates to a method and an apparatus for producing polyurethane foam with a controlled number of cells, in which a gas is dispersed in one of the components, i.e. the polyol or the isocyanate, in a dispersing device arranged between the mixing head and the metering pump for the respective component.

Abstract: In the production of a flowable reaction mixture of at least two flowable, also not readily miscible, reaction components which react completely with each other to form solid substance or foam material, a rapid abatement of the mixture flow is achieved with a compact type of construction after causing throttling at the discharge of the mixing chamber.

Abstract: In a fine comminution apparatus arranged downstream of a coarse comminution apparatus, polyurethane foam wastes can be comminuted to the desired particle size for recycling as an additive in the production of polyurethane, in a low-dust and energy-saving manner, by carrying out the fine comminution preferably by repeatedly forcing a mixture of the coarsely comminuted material and one of the reaction components through a nozzle or through a plurality of nozzles.

Abstract: A process and apparatus are described for the production of a flowable reaction mixture from at least two flowable reactive components which may be difficult to mix, which components react with one another to form a solid or a foam material. The components are injected into a mixing zone where the components are mixed in a continuous flow. The mixture flowing from the throttling zone is divided into two sub-streams which flow around a piston and which recombine opposite the division point.

Abstract: In order to guarantee substantially trouble-free operation when manufacturing sandwich elements on a double conveyor belt installation having a downstream cross cutter and cleaning device, the cleaning device disposed on a transport carriage i) is returned to the carriage of the cross cutter to pick up the next sandwich element, is braked and is then re-accelerated to a speed higher than the production speed, ii) is, after reaching a desired distance.

Abstract: In the continuous production of polyurethane block foam, in particular from fast-reacting reaction mixtures which expand with rise time of less than 1.5 minutes, to achieve a good foam quality and a rectangular cross-section a centrally disposed mixer (44) is used, disposed downstream of which is a rubber-elastic plate (22), which is located in the feeding table (21) and in turn has a centrally disposed prop (33), associated with which, at right angles to the production direction and mounted laterally and symmetrically relative to said prop, are at least two adjustable props (32).

Abstract: In the production of a reaction mixture which forms plastic material, in particular foamed plastic material, from at least two flowable reaction components, the inlet members or other switch-over members which must be switched over in a precise fashion, and controlled by a sliding valve comprising a slide which is assigned a restoring spring which operates in opposition to a moving electromagnet, and a holding electromagnet. First, the holding electromagnet is fully activated whereupon the moving electromagnet is activated. Following the build-up of force of the moving electromagnet, the holding electromagnet is switched off so that the inlet member or other switch-over member opens abruptly.