Wood-plastic composites (WPCs) are composite materials made of wood fiber/wood flour and thermoplastic(s) (includes PE, PP, PVC etc.).
Chemical additives seem practically "invisible" (except mineral fillers and pigments, if added) in the composite .
Advantages and disadvantages:
WPCs do not corrode and are highly resistant to rot, decay, and Marine Borer attack, though they do absorb water behavior.
The wood particles are susceptible to fungal attack, though not as much so as solid wood, and the polymer component is vulnerable to UV degradation. It is possible that the strength and stiffness may be reduced by moisture absorption and freeze-thaw cycling, though testing is still being conducted in this area. Some WPC formulations are also sensitive to staining from a variety of agents.
As time goes on, product defects have become well known. The industry leader (Trex Company, Inc.) has been involved in numerous lawsuits with home owners and installers in regards to mildew, discoloration and increased weakness in the fiber of the materials. As of mid 2008, Trex has replaced over 37,000 decks in regards to the issues previously stated and had to change their 'maintenance-free' claims to 'low-maintenance' explaining that decking would require cleaning multiple times every year to remove mildew spots.
Once more, in 2013, Trex notified consumers in 16 western states who may have purchased defective Trex decking product suffering from surface flaking to contact the company for replacement materials. Trex has previously announced that a small percentage of decking boards manufactured at its Fernley, Nevada plant between 2002 and 2007 suffered from surface flaking due to a manufacturing problem.
RAW MATERIAL-Polyvinyl chloride Pawder
Audited Supplier 
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