Effect of Load Levels and Plastic Type on Creep Behavior of Wood Sawdust/HDPE Composites

In this study, effect of load levels and plastic type on creep behavior of wood sawdust/HDPE (high density polyethylene) composites was investigated. The composites were manufactured using a dry blend/hot press method. In this method, powder of plastic and dried sawdust were mixed in a high speed mixer and then the mixed powder was pressed at 190 degrees C. Wood sawdust/HDPE composite panels were made from virgin and recycled high density polyethylene (as resin) and wood sawdust at 40% by weight HDPE loadings. Nominal density and dimensions of the panels were 1 g/cm(3) and 35 x 35 x 1 cm, respectively. Short term flexural creep behaviors of the panels were studied at 10, 20, 30, and 40% of maximum bending load. Results indicated that the composites containing virgin HDPE exhibited higher creep deflection and by increasing the recycled HDPE content the creep deflection decreased in all load levels. At high levels of load, the behavior of composites becomes distinctly non-linear in character. Irrecoverable creep deflections are higher at high levels and lower virgin HDPE. Creep behavior in studied WPCs followed the Findley power law.