Effect of polyethylene particle geometry on mechanical properties of compression moulded wood-polyethylene composites

The mechanical properties of wood-polyethylene composites have been studied. In such composites, post-consumer high density polyethylene (HDPE) flakes and virgin polyethylene pellets were used as the matrix material, while post-industry wood flakes were used as a discontinuous reinforcing phase. The composites were manufactured by compression moulding. The initial particle geometry of the polyethylene was found to play an important role in the quality of the final composites. The HDPE flakes could be consolidated with wood flakes into a high quality composite board by one step hot pressing without any previous surface treatment or adhesive. The results of three point bending and tension tests show that the mechanical properties of the flake start wood-polyethylene composites are stable, and better than for ordinary particleboard and softwood. Such a flake start process may be further developed to make various composite materials, in addition to the usual powder start and pellet start processes.