Advanced polymer/wood composite pellet process
AssigneeAndersen Corporation
InventorsMichael J. Deaner, Giuseppe Puppin, Kurt E. Heikkila
Life of this patent
Estimating the term…
Abstract
A process for making a polyvinyl chloride and wood composite pellet by extrusion. The polyvinyl chloride and wood fiber are introduced into the extruder at a ratio of approximately 6:4 by weight, respectively. The polyvinyl chloride is melted and blended with the wood fiber so that the interstitial voids of the wood fiber are filled with polyvinyl chloride. After being extruded through a die, the molten material is cut into pellets having a bulk density of preferably between 0.7 to 0.8 gm/mm.sup.3.
Claims10
A process for the manufacture of a pellet composite comprising thermoplastic polymer and cellulosic fiber, which method comprises:
- (a) introducing a thermoplastic polymer composition and cellulosic fiber having cells with an interior volume into an extruder, having at least an inlet zone, a second zone, a barrel and a pellet die, at a ratio of about 35-50 parts fiber to 45-70 parts of polymer per each 100 parts of the composite, the fiber having a length ranging from about 1-10 mm and an aspect ratio of at least 1.8;
- (b) melting the polymer composition in the barrel and blending the polymer composition with fiber under conditions of sufficient temperature, pressure and shear to cause the polymer composition to mix with the fiber to the extent that the polymer composition occupies greater than 50% of the interior volume of the cells of the fiber to form a polymer fiber composite;
- (c) extruding the composite through the pellet die to form a thermoplastic pellet comprising a right circular cylinder having a length about 1-10 mm and a radius about 1-5 mm;
- wherein the ratio of the density of a physical mixture of the fiber and polymer to the density of the pellet is less than 0.8.
Dependencies are inferred from the claim text.