Patent ID: 7736562

Claim:
A production process for the continuous production of a composite profile comprising composite compound comprising thermoplastic resin and cellulosic fiber and having a desired cross-section and an exterior surface, said production process comprising the steps of: a. providing thermoplastic resin and cellulosic fiber; b. compounding the thermoplastic resin and cellulosic fiber to produce the composite compound; c. processing the composite compound at a temperature above the softening point temperature of the thermoplastic resin through an extrusion system to produce a generally homogeneous flow of melted composite compound; d. extruding the generally homogeneous flow of melted composite compound through a die assembly having a flow passage to form a composite profile having the desired cross-section, wherein extruding comprises passing the homogeneous flow through a compression zone of the flow passage, said compression zone having an inlet and an outlet having a cross-sectional area smaller than the inlet, into a transition zone of the flow passage having an inlet and outlet, said inlet having a cross-sectional area larger than the area of the desired cross-section, passing the homogeneous flow from the transition zone into a converging die zone of the flow passage having an inlet, outlet and cross-section, said inlet having a cross-sectional area larger than its outlet and the cross-section of the converging die zone gradually changing to the desired cross-section at the outlet of the converging die zone, passing the homogeneous flow from the converging die zone into a die land having a cross-section the same as the cross-section to produce an extruded composite profile, maintaining the temperature of a portion of the die assembly containing the compression, transition and converging die zones at a temperature above the melting point temperature of the thermoplastic resin and maintaining the temperature of a portion of the die assembly containing the die land at a temperature below the melting point temperature of the thermoplastic resin; e. cooling the extruded composite profile until the composite compound comprising the composite profile is solidified; and f. cutting the cooled composite profile to the desired length.