Studies on Impact Fracture Properties of Wood-Polymer Composites

Composite plates containing pine wood chips and high density polyethylene (HDPE) matrix were prepared and studied for their impact fracture behavior using an instrumented drop weight tester. Maximum load sustained, deflection to maximum load, energy to maximum load and energy for total penetration of the test specimens were determined for the above-mentioned wood-polymer composites. Effects of pine chip concentration in composites and its particle size on impact damage resistance were analyzed. Large size wood chips in the 50 to 60 vol.% concentration range increased the energy to fracture and damage resistance considerably. This is attributed to the internal friction forces encountered between such large sized chips restricting the deformation and contributing to uneven perforation. On the contrary, specimens with small sized wood chips in similar composition range perforated evenly consuming less energy than needed to perforate even the polymer alone.