Abstract: A process is described for the production of a curable multi-component reaction mixture (and, in particular, a polyurethane), containing filler in which the reaction components are premixed and then mixed with the dry filler in a friction mixer having a conically shaped screw rotatable in a conical mixing chamber. The friction mixer is preferably operated under a fractional load at a low rotational speed.

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: Leakage problems can be avoided in an apparatus for the preparation of a solid or cellular plastic-forming, flowable reaction mixture of at least two flowable reaction components and at least one additional component, by providing in the feed pipe of one of the reaction components a mechanical pre-mixer having a stirrer shaft. Upstream of the pre-mixer, a hydraulic motor comprising two meshing toothed wheels which is driven by the components themselves, is disposed in a manner such that one of the toothed wheels is disposed on an extension of the stirrer shaft, and wherein the bearings of the toothed wheels and the stirrer shaft are outwardly enclosed.