Image Number 6 for United States Patent #6502978.
A process and an apparatus for the production of a polyurethane mixture is described. The apparatus comprises a high-pressure mixing device provided with a mixing chamber opening onto a side of a discharge duct.An elongated cleaning member is reciprocable inside the duct and is provided with a longitudinal channel for feeding a fluidized reinforcing material, for example reinforcing fibers or a reinforcing material in powder or granulate form, to be blended with the polyurethane mixture flowing into the discharge duct. The feeding channel for the reinforcing material terminates at the front end of the cleaning member, at a point where the flow of reinforcing material impinges the polyurethane mixture which emerges from the mixing chamber under high turbulence conditions. Blowing nozzles are provided to generate air jets for repeatedly deviating the flow of blended polyurethane mixture and reinforcing material flowing out from the discharge duct.