Wood–plastic composite

Chemical additives provide for integration of polymer and wood flour (powder) while facilitating optimal processing conditions.

The company that invented and patented the process to create WPC was Covema of Milan in 1960, founded by Terragni brothers (Dino and Marco).

[1][2] After a few years from the invention of the Plastic-Wood the company Icma San Giorgio patented the first process to add wood fiber/wood flour to the thermoplastics (WPCs).

The most widespread use of WPCs in North America is in outdoor deck floors, but it is also used for railings, fences, landscaping timbers, cladding and siding, park benches, molding and trim, prefab houses under the tradename Woodpecker WPC.,[4] window and door frames, and indoor furniture.

A large variety of injection molded parts are also produced, from automotive door panels to cell phone covers.

[12] Due to the addition of organic material, WPCs are usually processed at far lower temperatures than traditional plastics during extrusion and injection molding.

[13] Processing WPCs at excessively high temperatures increases the risk of shearing, or burning and discoloration resulting from pushing a material that is too hot through a gate which is too small, during injection molding.

WPCs do not corrode and are highly resistant to rot, decay, and marine borer attack, though they do absorb water into the wood fibers embedded within the material.

[14] Water absorption is more pronounced in WFCs with a hydrophilic matrix such as PLA and also leads to decreased mechanical stiffness and strength.

WPC boards show a good set of performance but monolithic composite sheets are relatively heavy (most often heavier than pure plastics) which limits their use to applications where low weight is not essential.

The inclusion of plastic as a portion of the composite results in the potential for higher fire hazards in WPCs as compared with wood.