COMPOSITE-MATERIALS FROM RECYCLED MULTILAYER POLYPROPYLENE BOTTLES AND WOOD FIBERS

The feasibility of combining recycled multi-layer polypropylene (PP) bottles with untreated hardwood aspen fiber was tested by evaluating mechanical properties of reclaimed polymer and virgin PP composites. The bottles consisted of 3.75% ethylene vinyl alcohol, 1.75% adhesive, and 94.5% random copolymer ethylene and propylene. The wood fiber was obtained from thermomechanical pulp (TMP). Up to fifty weight-percent of wood fiber was incorporated into the matrix, utilizing twin-screw extrusion followed by compression molding. Orientation of the wood fiber improved mechanical properties. The PP-reclaim-wood fiber composite was superior to the virgin PP composite, possibly due to increased adhesion at the interface. The multilayer material also exhibited better dimensional stability under extreme environmental conditions.