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.

Abstract: The invention is directed to a filter device for the removal of coarse components from a liquid component used in the manufacture of plastic materials. The filter device has a hollow housing in which a rotor is mounted. The rotor is provided with agitator blades which comb out any dead-flow zones.

Abstract: In order not to have to rinse, during breaks in production, oscillating mixheads such as are used for the manufacture of free-flowing, plastic-forming reaction mixtures, an exchangeable insert part held in position by means of a clip and preferably consisting of plastic material is provided in the mixhead. The insert has a mixing chamber and an outlet channel. This insert part can be disposable or reusable.

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: The maintenance of the exact metering ratio during the production of plastics, particularly foams, from free-flowing reactants loaded with pulverulent to fine-grained or fibrous additives can be improved by mixing the additive in compacted form in a preliminary mixer with at least one of the reactants. The pressure in the preliminary mixer is kept constant.

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 they components are mixed in a continuous flow. The mixture flowing from the throttle zone is divided into two sub-streams which flow around a piston and which recombine opposite the division point.

Abstract: The present invention is directed to an apparatus for introducing gas into one of at least two free-flowing components which are subsequently mixed to provide a foam-forming free-flowing mixture by transferring the component to have gas dispersed therein from a supply container to a gas loading area, loading the component with gas and returning the component to the supply area, wherein the gas used in the gas loading area is obtained from a gas cushion maintained in the supply container and wherein the gas is compressed to a pressure higher than the pressure in the gas loading area before it is dispersed into the free-flowing component.

Abstract: The invention relates to a nozzle for mixing at least two flowable (and in particular foam-forming) reaction components comprising a housing; component supply pipes leading into the housing; a housing bore arranged in the housing having a coaxial outlet channel in its end face; at least one needle casing arranged coaxially in the housing bore; an injection needle guided coaxially in the needle casing; a first chamber arranged between the wall of the housing bore and the needle casing with one of the component supply pipes opening into said first chamber; a second chamber arranged between the needle casing and the injection needle, with another component supply pipe opening into said second chamber; wherein in the closed state, said injection needle forms a tight fit with the internal end face of the needle casing, and the external end face of said needle casing forms a tight fit with the internal end face of the housing bore; and wherein in the open state, said injection needle frees a coaxial nozzle opening

Abstract: In order to keep the reversing times from circulation of the reaction components to mixing and vice versa as short as possible for the purpose of good mixing in the initial and end phases in the preparation of flowable reaction mixtures by high-pressure mixing, the holding pressure applied to the flow reversing element is maintained by a releasable non-return valve until the full hydraulic reversing pressure has built up on the opposite side, and only then is the non-return valve released.

Abstract: To avoid contaminating the sprue runner which leads from the mixing device to the molding cavity of a molding tool for the production of molded plastic, especially foam plastic, parts, an insertable lining is placed in the sprue runner and can be removed along with the molded part.