Patent ID: 6153293
Filing Date: 2000-11-28
Classification: B27N,B29C,B29K,Y10S,Y10T

Abstract:
A process for manufacturing a composite extruded structural product having a desired profile from thermoplastic material and wood fiber comprising the steps of:finely dividing the thermoplastic material and wood fiber each into particles no smaller than about 0.007 inches and no larger than about 0.5 inches in length;mechanically mixing together the thermoplastic particles and the wood fiber particles in a ratio of between 60%-40% and 40%-60% by weight, together with an effective amount of a foaming agent, to form a feedstock mixture;introducing the feedstock mixture, without pre-pelletization, into a screw-type extruder;mechanically mixing, compressing and heating said feedstock mixture in said extruder until it becomes plastic and homogenous;extruding said heated, plastic, homogenous mixture through a molding die into the structural profile of a desired product;cooling said extruded product upon emerging from said molding die; andcutting the cooled extruded product into desired lengths.