New Technology for Enhancing Wood-Plastic Composites

By Kelly Williams, Bernard Bauman

Wood-plastic composites (WPC) are the combination of wood fibers,most commonly wood flour waste, and a thermoplastic such as high density polyethylene (HDPE), polypropylene (PP), or PVC. The polymer content is generally 40-50% by weight. WPCs are extruded into profile shapes via continuous extrusion for the building and construction products industry as an alternative to wood and treated wood.

Consumers are choosing WPC over wood, even though it costs more, because of lower maintenance requirements and aesthetic appeal. WPC does not require painting, resists warping and termite attack, and is generally resistant to moisture-related issues such as mold development. The WPC industry has been growing faster than any other plastics industry since its emergence in the late 1980s.¹ The market segments that have supported the annual growth rates of over 25% since 1998 have been largely decking and railing.

The overall WPC industry has recently surpassed one billion pounds per year of manufactured composites in North America,s.^1,2  In decking, WPC have assumed nearly 20% market share versus treated lumber. ^1,3 Even though the recent multi-year boom in the housing industry helped buoy the continued industry growth, Wall Street analysts still predict a bright outlook for the industry even though the housing industry has officially softened.³

The prediction is for WPC to continue to capture upwards of 20% unit share ( 40% dollar share) relative to treated wood.4 This continued growth is due to several key factors such as the increasing access and availability of products through retailers and contractor distributors as well as continued consumer demand, especially in outdoor living structures.