Abstract: A molding tool for the production of plastics moldings by the reaction injection molding process is described. These plastics moldings are preferably prepared from a reaction mixture comprising a polyurethane molding composition. The molding tool comprises at least two molding tool halves, i.e. an upper mold half and a lower mold half, which together form a mold cavity when in the closed position, a supply pipe for transporting the reaction mixture via an external mixing head connector which connects the supply pipe to an external mixing head, a storage chamber which receives the reaction mixture from the supply pipe, and a plunger which is movably arranged in the storage chamber, characterised in that the end face of the plunger forms part of the inside wall of the mold cavity formed by the two mold halves when the plunger is in the extended state.

Abstract: The coating of bodies rotating about an axis with a reaction mixture forming a polyurethane can be improved by making use of a sheet die disposed parallel to the axis of rotation of the body at an angle .alpha., whereby the rate of reaction of the reaction mixture and the relative movement are synchronized with the circumferential speed of the rotating body in such a way that the successive convolutions overlap in the form of scales and connect together seamlessly.