Abstract: The present invention is directed to a process and corresponding device for incorporating expanded graphite in a gentle manner into a polyurethane reactive mixture and, on the other hand, processes and corresponding means for reducing or preventing sedimentation of the expanded graphite in the liquid.

Abstract: The present invention is directed to an agitator-free mixing head and a method for agitator-free production of a reaction mixture from an isocyanate and a higher-viscous polyol formulation, wherein both constituents are fed to a mixing zone and mixed with each other therein, whereby a polyol formulation with a viscosity of at least 3000 mPa.s is fed at low pressure into the mixing zone and at least two flows of low-viscosity constituents (isocyanate and optionally low-viscous polyol) are injected into the flow of high-viscous polyol formulation at high pressure.

Abstract: An apparatus for the continuous production of foamed plastics is described. The apparatus includes i) a continuous conveyor belt, and ii) a transversely reciprocating applicator device located over the belt for applying a foam-forming reaction mixture. The applicator device includes a mix head and a detachably mounted magazine plate having several openings thereon. Each opening has a casting tube connected thereto. Each casting tube has discharge holes on its underside. The plate is adjustable in such a way that the casting tubes can be connected successively to the outlet of the mixhead.

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: The present invention relates to a process and a device for uniform distribution of a free-flowing reaction mixture onto a continuously transported substrate over the desired width during production of foam webs. The distribution takes place towards the sides from a feed point by means of air.

Abstract: An apparatus for continuously charging a liquid reactant with a gas is provided. The gas is dispersed in the reactant through a hollow stirrer in a gassing tank. The quantity of gas introduced per unit time is kept constant.

Abstract: The present invention relates to an improved apparatus for the production of a flowable mixture which reacts to form foam from flowable components stored in storage containers, wherein prior to metered introduction into a mixing zone, at least one of the components is charged with a defined quantity of gas, by (i) introducing said one component and gas separately into a gasification chamber equipped with a hollow stirrer, (ii) sucking gas into said component through the hollow shaft of the hollow stirrer, and (iii) stirring the gas into the component, until the desired value is attained, the improvement wherein (a) the component is circulated from the storage container through the gasification chamber and back into the storage container, (b) the gas sucked through the hollow shaft of the hollow stirrer being maintained at pressure at least equal to the pressure prevailing in the storage container, and (c) the component fraction remaining in the storage container is homogenized during those periods in which ga

Abstract: The present invention is directed to a novel process and apparatus for charging a liquid reactant with a gas. In the process, the liquid reactant which is as yet uncharged with gas is introduced into the gassing tank at a point just below the substantially constant liquid level of the reactant. When the reactant has been charged with gas, it is removed at a point below the region where gassing takes place. A three-layered arrangement is thereby established and maintained in the gassing tank so that the layer of gas is separated from the layer of gas charged component by the layer of uncharged component. The gas charged component is thus maintained at a density corresponding to the desired gas content, taking into account any significant starting conditions, such as the original density, the temperature and the pressure. If necessary, this density is maintained by suitably varying the stirrer speed.

Abstract: The present invention is directed to a process for charging a component with a gas. The gas is metered through a hollow stirrer into the component to be charged with gas. The stirrer is operated at a higher gas throughput capacity than the amount of gas metered.

Abstract: The present invention relates to an improved process for the production of a flowable mixture which reacts to form foam from flowable components stored in storage containers, wherein prior to metered introduction into a mixing zone, at least one of the components is charged with a defined quantity of gas, by (i) introducing said one component and gas separately into a gasification chamber equipped with a hollow stirrer, (ii) sucking gas into said component through the hollow shaft of the hollow stirrer, and (iii) stirring the gas into the component, until the desired value is attained, the improvement wherein (a) the component is circulated from the storage container through the gasification chamber and back into the storage container, (b) the gas sucked through the hollow shaft of the hollow stirrer being maintained at a pressure at least equal to the pressure prevailing in the storage container, and (c) the component fraction remaining in the storage container is homogenized during those periods in which ga

Abstract: This invention relates to a process for the preparation of polyurethane foams by the reaction of a foamable reaction mixture. A liquid blowing agent is added to either the isocyanate or the polyol prior to mixing of the components. An inert gas is dispersed in the component which contains the blowing agent and the gas charged component is immediately and continuously mixed with the other component, at the same time keeping it at least under the pressure required for charging it with gas until mixing has been completed, and leaving the resulting reaction mixture to foam up. The key to the present invention is in the small amount of gas charging.

Abstract: The present invention relates to a process and device for applying a reaction mixture to a moving base. The key to the invention resides in the use of compressed air to ensure even distribution of the mixture. The reaction mixture is applied via an elongated pipe-like applicator vessel which extends laterally across the moving base. A cushion of compressed air is maintained in the applicator vessel above the reaction mixture.

Abstract: The present invention is directed to an apparatus for applying a foam-forming flowable reaction mixture onto a substrate comprising an applicator tube connected to a mixer, said tube being provided with outlet openings and extending transversely over the substrate, further characterized in that the applicator tube is connected to a vibrating means.

Abstract: The present invention relates to an apparatus for the production of a solid-forming or a foam-forming reaction mixture from at least two flowable components, the apparatus comprising a mixing head, at the outlet opening of which is connected at an angle a filling tube in which an ejection piston which is designed as a piston head and having a piston rod of a smaller diameter is positioned, the rear neutral position of the piston head being located upstream of the outlet opening of the mixing chamber, characterized in that an introduction slit is provided in the filling tube between the rear neutral position of the piston head of the ejection piston and the outlet opening of the mixing chamber and a delivery device for cleaning platelets is associated with the introduction slit.

Abstract: The invention relates to equipment for the continuous production of foam boards, which may be laminated between facings, from a liquid foamable reaction mixture. The apparatus broadly comprises a conveyor, a foam mixture application device located at or near one end of the conveyor and a transverse foam mixture distribution device located downstream of said application device and above said conveyor, the space between said distribution device and said conveyor being adjustable.

Abstract: The instant invention relates to a method and apparatus for measuring the proportion of undissolved gas in a liquid component for the production of foam materials, particularly those based on polyurethanes. The method is based on the equation of state of ideal gases (Boyle-Mariot Law: p.multidot.v = constant) at constant temperatures. The gaseous portion of a liquid component charged with gas increases its volume under expansion according to the above equation. The gas expansion also increases the liquid volume. The differences in the volumes, of the liquid at two differing pressures is therefore a measurement of the quantity of gas present in the liquid. The apparatus consists of a closed graduated measurement vessel being connected to a variable pressure means capable of producing at least two different defined pressures.