Firma Carl Freudenberg

Michael Brehm

Peter W Rutsch

Kurt Weber

A fiber reinforcement is positioned on the female part of a matched die, and a reactive foaming mixture of polyol and isocyanate is placed on the reinforcement, the male part of the die set being then closed on the female part so as to compress the reinforcement and holding the die parts together while the mixture's foaming reaction occurs. So that the reinforcement can comprise finer than usual individual fiber thicknesses and be compressed more than usual by closing of the die while still filling all the voids between the fibers of the reinforcement with the foam produced by the mixture's reaction, from 5 to 30% by weight of a neutral ester having a boiling temperature higher than the foaming reaction temperature of the mixture, is initially added to the mixture before it is placed on the reinforcement and prior to closing of the die. This results in the foaming penetrating the voids between the fibers throughout the reinforcement between the mold parts more completely than is possible without using the ester.

Method for matched die molding a fiber reinforced polyurethane foam

In the production of a polyurethane foam by supplying two or more components to a machine, mixing said components, extruding the mixture to form a foaming mass, subsequently discontinuing supply and extrusion, rinsing the machine, and subsequently resuming supply and extrusion, the improvement which comprises effecting said rinsing with a rinsing agent having the approximate weight composition

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Weinheim, Germany

Michael Brehm