Abstract: A process is described for the production of optionally cellular polyurethane moldings with an elevated ground material/filler content, which process broadly comprises a) mixing and reacting an aromatic di- or polyisocyanate with a di- and/or polyol of a molecular weight of 1,000 to 20,000 in a quantity insufficient to react with all the NCO groups to yield an isocyanate pre-adduct with an NCO group content of 5 to 32%, b) mixing this isocyanate pre-adduct with ground material/filler, c) mixing the resultant mixture, with a di- and/or polyol with a molecular weight of 62 to 2,000 (crosslinking agent), and optionally water and/or an organic blowing agent, in a static mixer and d) introducing the resultant mixture into a mold.

Abstract: The present invention is directed to a process for the manufacture of molded parts having areas in the form of grids, grills or gratings, in which a fluid mass is introduced into the mold cavity of a molding tool conforming to the molded part and the cavity is filled by said fluid mass, characterized in that in the mold cavity, the zones provided for the apertures in the areas conforming to the said grids, grills or gratings of the molded part are first flooded by the mass and the mass is subsequently displaced from these zones, and to a molding tool to be used in such process.

Abstract: This invention is directed to a process and apparatus for mixing a pulverulent or small particle size additive into at least one of the liquid reaction components for the preparation of a reaction mixture which forms a solid substance or a foam, wherein the reaction components are introduced into separate chambers and subjected to turbulence by stirring and the pulverulent additive is stirred into at least one of the reaction components and that liquid reaction component charged with the additive is transferred into a second reaction component and mixed therewith.