Wood plastic composites (WPCs)are roughly 50:50 mixtures of thermoplastic polymers and small wood particles.The wood and thermoplastics are usually compounded above the melting temperature of the thermoplastic polymers and then further processed to make various WPC products. WPC can be manufactured in a variety of colors,shapes and sizes,and with different surface textures.Depending on the processing method,WPCs can be formed into almost any shape and thus are used for a wide variety of applications,including windows, door frames,interior panels in cars,railings,fences,landscaping timbers,cladding and siding,park benches,molding and furniture.
WPCs offer a number of potential benefits.The presence of wood in a plastic matrix can result in a stiffer and lower-cost material than if plastic alone was used.Also, the compression properties(resistance to crushing)for most WPCs are superior to that of wood loaded perpendicular to the grain.The plastic in the product is not subject to water absorption or biological attack,so the WPC can have lower maintenance requirements than solid wood.WPC lumber will not warp,splinter or check.
The use of wood–a natural and renewable resource–can reduce the“carbon footprint”of plastics,because less fossil energy and material are required to make the final product.WPCs are also potentially recyclable,because recovered material can be melted and re-formed.WPCs may be identified as sustainable materials,due to the wood particles predominately being a byproduct of sawmill and other wood-processing waste streams,and because much of the plastic is derived from consumer and industrial recycling efforts.
WPCs offer great flexibility in the shapes and colors of the materials produced.Materials usage can be also be reduced through the engineering of special shapes–e.g., hollow-core decking boards.