Because of considerable crosslinking induction during weathering, the exposed HDPE did not exhibit a thermoplastic melt flow and failed to fill the mold. Fig. 2 shows the image of the flexural and tensile sample of WPCs (containing a different content of highly crosslinked HDPE) prepared by injection molding (Kazemi-Najafi and Englund, 2013). By increasing the crosslinked HDPE content to 20% or higher, the mold could not be filled by the wood flour-HDPE blends. This phenomenon indicates the poor processibility of highly degraded and crosslinked HDPE.