The effects of recycling on the physical and mechanical properties of wood plastitc composite made with high density polyethylene

Although many studies have been done about the application of waste materials such as used plastics but returning of wood plastic products (Regrind) to the production cycle was rarely reported. In this work, the effect of once and twice regrind on the functional properties of WPC made from high density polyethylene (HDPE) has been studied. The specimens were fabricated with powder raw materials and by the flat press under laboratory conditions. HDEP and poplar wood flour were mixed with a weight ratio of 50-50 percent. The estimation of regrind process, physical and mechanical properties of boards were measured after each regrinding and also to evaluate of regrinding on filler particle size and the interface between the polymer and wood flour some Scanning Electron Microscopy (SEM) were prepared. The results of this research showed that regrinding of WPC leads to a decrease in mechanical properties including bending strength, flexural modulus, tensile strength and tensile modulus and on the other hand regrinding process leads to improved physical properties including water absorption and thickness swelling after hours. SEM photographs showed that during the process of regrinding, filler particle size is reduced while matrix surrounding the filler particles better.