Determination and Comparison of Material Properties of Commercial Wood-Plastic Composite Products

Abstract

Outdoor applications of wood-plastic composites (WPCs) have raised question about the durability of such materials. WPCs are vulnerable to weathering factors such as UV radiation, moisture and freeze-thaw action. Weathering can cause discoloration, chalking, dimensional changes and loss of mechanical properties.This comparative study examines the effects of increased moisture content and artificial weathering on the properties of wood-plastic composites. Five commercial wood-plastic composite products from five different manufacturers were chosen and their water absorption, thickness swelling, impact strength and resistance to artificial weathering analyzed. An in-house manufactured wood-polypropylene composite with carbon black pigment was used as a reference product. In addition to quantitative investigation of material properties, the measured values were also compared with the values ​​reported by the manufacturers.The composite samples were exposed to accelerated weathering in a xenon weathering chamber for 500 hours. The color change was estimated by spectrophotometer method. The weathering resulted in no significant color fading of the composites. After weathering, the general trend was a minor decrease in impact strength. Also the water absorption and thickness swelling of commercial WPC products remained on a low level.