the invention relates to a composition comprising a thermoplastic polymer and wood fiber composite that can be used in the form of a linear extrudate or thermoplastic pellet to manufacture structural members . the polymer , the fiber or both can be modified to increase compatibility . the wood fiber composite structural members can be manufactured in an extrusion process or an injection molding process . the linear extrudate or pellet can have a cross - section of any arbitrary shape , or can be a regular geometric . the pellet can have a cross - section shape having a volume of at least about 12 mm 3 . preferably the pellet is a right cylindrical pellet having a minimum radius of about 1 . 5 mm and a minimum length of 1 mm weighing at least 14 mg . the invention also relates to an environmentally sensitive recycle of waste streams . the polymer and wood fiber composite contains an intentional recycle of a waste stream comprising polymer flakes or particles or wood fiber . the waste stream can comprises , in addition to polymer such as polyvinyl chloride or wood fiber , adhesive , paint , preservative , or other chemical stream common in the wood - window or door manufacturing process , or mixtures thereof . the initial mixing step before extrusion of the composite material insures substantial mixing and melt contact between molten polymer and wood fiber . the extruded pellet comprises a consistent proportion of polymer , wood fiber and water . during the extrusion , water is removed intentionally to dry the material to a maximum water content of less than about 10 wt -% based on the pellet weight . to make a structural unit , the pellet is introduced into an extruder or injection molding apparatus wherein , under conditions of temperature and pressure , the composite pellet material is shaped into a useful cross - section . alternatively , the extruded thermoplastic mass , in the form of a elongated linear extrudate without a pelletizing step , can be immediately directed after formation into an extruder or injection molding apparatus .