Because of the limited thermal stability of wood only thermoplastics that melt below 200 Deg C are commonly used in WPCs. Currently, most WPCs are made with PE, both virgin & recycled, for use in exterior building components. However, WPCs made with wood –PP are typically used in automotive & consumer products and very recently, these materials have been investigated for use in building profiles. Wood filled PVC composites typically used in window manufacture are now being used in decking as well. Polystyrene & ABS are also being used. The plastic is often selected based on its inherent properties, product need, availability, cost and the manufacturer’s familiarity with the polymer.The wood used in WPCs is most often in particulate form (wood flour) or very short fibers, rather than longer individual fibers. Products typically contain 50 % wood, although some composites contain very little wood Composite wood decking.
Others contain as high as 70 %. The relatively high bulk density & free flowing nature of wood flour compared with wood fibers or other longer natural fibers, as well as low cost, and availability, is attractive to WPC manufacturers and users. Common species used include pine, maple, & oak. Typical particle sizes are 10 to 80 mesh Wood Plastic Composite Floor.
Since the early 1990’s, the wood – plastic composite industry has grown significantly. Today, wood & other natural fibers account for 7% of the total 2.5 billion kgs filler & reinforcement used. This represents a 135 % increase in natural fiber demand since 1990 with most of the growth in the past five years. The price of wood is dependant on the location. Low cost wood in the USA can be attributed to the considerable amount of wood residues (60 Million metric tones) generated just from the primary timber processors. The growth of wood flour & fiber use in thermoplastics has outpaced that of other natural fibers. Natural fibers are roughly twice as expensive as wood fiber, but are still well below most other Composite wood plastic.