Considerations in the Weathering of Wood-Plastic Composites

During weathering, wood-plastic composites (WPCs) can fade and lose stiffness and strength. Weathering variables that induce these changes include exposure to UV light and water. Each variable degrades WPCs independently, but can also act synergistically. Recent efforts have highlighted the need to understand how WPCs weather, and to develop schemes for protection. The first plan of attack is often to adapt photostabilizers currently used to protect polyolefins in WPCs. Another effective option is to improve the surface of the WPCs by changing manufacturing methods and/or conditions. This paper identifies three main factors that influence WPC weathering; photostabilization, processing conditions, and weathering variables. The effect of each factor is discussed, and an example presented in detail