Abstract: A process is described for producing foam materials from two-component reactive plastics using carbon dioxide as blowing agent by mixing at least one of the reactive components with carbon dioxide under pressure, mixing the components, at least one of which contains carbon dioxide under pressure, expanding the reactive mixture containing carbon dioxide obtained by mixing, and hardening, wherein the expansion takes place suddenly with the production of high rates of shear. Preferably the rate of flow of the reaction mixture is reduced after expansion.

Abstract: A process is described for producing foam materials from two-component reactive plastics using carbon dioxide as blowing agent by mixing at least one of the reactive components with carbon dioxide under pressure, mixing the components, at least one of which contains carbon dioxide under pressure, expanding the reactive mixture containing carbon dioxide obtained by mixing, and hardening, wherein the expansion takes place suddenly with the production of high rates of shear. Preferably the rate of flow of the reaction mixture is reduced after expansion.

Abstract: A process and a device are described for the continuous production of block foam by the foaming of a mixture which reacts to form polyurethane and which contains carbon dioxide dissolved under pressure, wherein the pressure of the reactive mixture is reduced on passing through a pressure reduction zone in the form of an aperture, and blockage of the aperture is prevented by the relative movement of the aperture-delimiting faces with respect to each other.

Abstract: A process is described for the continuous production of polyurethane block foam using carbon dioxide which is physically dissolved under pressure as a foaming agent, wherein before the polyol and isocyanate components are mixed the carbon dioxide is dissolved in the polyol component and air or nitrogen is dissolved in the isocyanate component, both components are fed to a mixing chamber in which a pressure prevails which is 70 to 150% of the solution pressure of the CO.sub.2 in the polyol component, the isocyanate component is fed to the mixing chamber at a pressure of at least 30 bar and is injected therein with depressurization down to the mixing chamber pressure, wherein air or nitrogen in an amount of at least 1 g per kg CO.sub.2 is dissolved in the isocyanate component, and after emerging from the mixing chamber the mixture is depressurization to atmospheric pressure.

Abstract: A process and device for the continuous production of slabstock foam by foaming a polyurethane reactive mixture containing carbon dioxide dissolved under pressure, comprising the steps ofa) feeding said polyurethane reactive mixture into a linear extended pressure distribution chamber at a pressure above that of the solubility vapor pressure of said dissolved carbon dioxide,b) reducing pressure to a pressure below said solubility vapor pressure of said dissolved carbon dioxide in a linear extended pressure reduction zone,c) feeding said polyurethane reactive mixture from said pressure reduction zone into a foaming chamber with a widening cross-section of flow to form a foamed reactive mixture, andd) applying said foamed reactive mixture (froth) substantially perpendicularly and free-flowing onto a conveyer belt of a continuous slabstock foam plant.

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 is described for producing foam materials from two-component reactive plastics using carbon dioxide as blowing agent by mixing at least one of the reactive components with carbon dioxide under pressure, mixing the components, at least one of which contains carbon dioxide under pressure, expanding the reactive mixture containing carbon dioxide obtained by mixing, and hardening, wherein the expansion takes place suddenly with the production of high rates of shear. Preferably the rate of flow of the reaction mixture is reduced after expansion.

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 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: 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: The variations in the delivery rate of additive caused by fluctuations in a system for the preparation of a polyurethane reaction mixture from flowable reactants and an additive, in particular a blowing agent, are kept within negligible limits by subdividing the supply pipe (4) to the mixing head (6) into a main pipe (8) and a subpipe (9) and introducing the additive into the side stream, which is substantially smaller than the main stream.

Abstract: In devices for the production of a reaction mixture, which forms a foamed plastic, from at least two reaction components and a foaming agent, it is possible to determine the content of foaming agent in a reaction component mixed therewith in that an intermediate container is provided for this mixture. The intermediate container is provided with a circulating line in which are arranged a circulating pump and a temperature-compensating viscometer. Optionally, the foaming agent content can be automatically adjusted to the theoretical value via a computer and pulse lines by influencing the drive means of the dosing pumps for the respective reaction component and the foaming agent.

Abstract: A piston metering device for the production of a plastic material from at least two flowable reaction components. This device is basically composed of (a) a hydraulic driving mechanism, (b) two piston cylinder units, (c) a mixer head and, optionally, (d) a control device common to at least one of the piston cylinder units. This device permits rapid and simple adjustment of the metering ratio of reaction components by adjustment of throughput. Such adjustment is accomplished by means of regulating elements made of hydraulic motors rigidly coupled to one another.

Abstract: The invention relates to a method and a device for producing a reaction mixture from flowable foam-forming or solid-forming components (preferably polyurethane forming components) which are conveyed continuously and are mixed together or are circulated. The quantity to be conveyed is preselected. The injection pressure is preselected and the circulatory pressure is measured for each component. The predetermined quantity and pressure to be conveyed as well as the measured value are preferably fed into a control computer during the circulation and the mixing process and are compared with actual values. Cavities are filled out with the reaction mixture produced and, in particular, molded articles are produced in molds.

Abstract: The invention relates to a method and a device for producing a reaction mixture from flowable foam-forming or solid-forming components (preferably polyurethane forming components) which are conveyed continuously and are mixed together or are circulated. The quantity to be conveyed is preselected. The injection pressure is preselected and the circulatory pressure is measured for each component. The predetermined quantity and pressure to be conveyed as well as the measured value are preferably fed into a control computer during the circulation and the mixing process and are compared with actual values. Cavities are filled out with the reaction mixture produced and, in particular, molded articles are produced in molds.

Abstract: The present invention relates to a process and apparatus for preparing flowable reaction mixtures.

Abstract: A method for the continuous production of foam blocks or foam sandwich panels involving the application of the liquid foamable reaction mixture to the continuously moving shaping support in a manner which avoids large gas inclusions in the final product produced. The liquid foamable reaction mixture is preliminarily distributed by the use of a particular distributor channel means in a traverse direction to the continuously moving shaping support, permitted to flow in the form of a descending film exposed to the atmosphere to an intermediate storage means and then conveyed to said continuously moving shaping support. The distributor channel means may also be pivoted to control the outflow of the mixture.

Abstract: The instant invention is directed to a process for the continuous production of block-shaped foam and to the equipment used therefore. The process of the invention broadly involves the heating of the bottom film prior to application of the foamable mixture. In this way, the undesirable crust generally formed on the bottom of the foam blocks is substantially reduced and/or eliminated.

Abstract: The invention relates to a method of and an apparatus for producing a foam-forming reaction mixture of at least two liquid components which react together and which are fed continuously to a mixing zone where they are mixed together. The volumetric flow of at least one component is measured continuously both in the main pipe leading to the mixhead and also in a subsidiary pipe which branches off the main feed line between the storage for the components and its pump. This subsidiary stream serves as a source for intermittent weighing of the component so that the density of the reaction component can be periodically calculated and monitored. This helps ensure the proper mass of component entering the mixhead.An apparatus is disclosed which achieves precise dosing of the components so that a product free of defects and having the desired properties may be produced.