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 apparatus are described for the continuous production of polyurethane slabstock foam by applying a polyurethane reactive mixture in the form of a liquid foam from a substantially punctual source onto the conveyor belt of a slabstock foam plant and distributing the liquid foam transversely across the width of the conveyor belt by means of a distribution device arranged above the conveyor belt, to form a distribution slot, wherein the distribution device is in the form of a stationary plate.

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: 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 invention relates to a method and an apparatus for the continuous production of foam blocks or sheets having an essentially rectangular cross-section from a foamable, liquid reaction mixture, possibly in the form of a liquid froth, in which the reaction mixture is applied from a stationary mixing head onto a moving lower facing sheet inclined in the longitudinal direction. An upper covering sheet is supplied from above and is brought into contact with the reaction mixture by means of a deflecting element. The deflecting element is flat in the longitudinal direction, so that a channel with an essentially constant cross-section is formed between the lower facing sheet and the upper covering sheet guided by the deflecting element, the length of which channel in a longitudinal direction is several times greater than its central height H.sub.M. The deflecting element can be oscillated about an axis at the entry end where it rests on the reaction mixture by the application of pressure.

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 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.