Wood-plastic composites: the world view

The sudden popularity of wood-plastic composites is not just a North American phenomenon. Products made of plastic and wood fibre are attracting interest in both Asia and Europe, and uses abroad aren’t limited to deck boards.

“The European market is in a much, much earlier stage of development than North America,” reports David Plackett, a professor at the Danish Polymer Center, Technical University of Denmark. “There’s a lot of interest but very few companies in full operation. We believe this will change. It looks like window profiles will be a developing business.”

Plackett told attendees of the Progress in Woodfibre-Plastic Composites Conference, held in May in Toronto, that he forsees use for WPC in cladding (siding), profiles (window lineals especially) and decking. Most WPC composites for the building products market in Europe are now using polypropylene as the base resin.

Early entrants to the European market are a Dutch company called Techwood (decking and siding), a Swiss company named Polima, and Polyplank from Sweden (cladding materials and noise barriers).

“The interest in WPC seems to be coming from small- and medium-sized enterprises, who will likely turn to licensing technology from international companies as a way to enter the market,” says Plackett.

Philip Walsh of PSAC agrees that Europe is on the verge of a breakthrough. PSAC is a Canadian licensor of wood-plastic extrusion technology. Walsh is in charge of business development for PSAC in the European market. “I think Europe will take off all at once. Everyone is just hesitant to be the first.”

He noted that three of the largest plastics processors in Britain were attending the Toronto wood-plastic composites conference.

Japan well advanced in WPC use

On the other hand, Takeyasu Kikuchi of Ein Engineering Co. Ltd. in Japan, said there has been tremendous acceptance of WPC in Japan. His company, which licenses a WPC extrusion technology, has just introduced wide panel products for interior or exterior use. The sample he had at the conference was greeted with amazement for its straightness and consistent wall thickness.

He explained that the EinWood technology reduces the moisture content of the wood flour to virtually zero and uses a reinforcing agent to increase adhesion between the wood fibres and resin. “In this way, we produce a distortion-free wood composite.”

In 1999, Japan had about 29 producers of wood composites; 68% of those were licensees of Ein technology.

To ensure a supply of raw materials, Ein Engineering established a collection system for wood waste, primarily from construction sites. The company also secured government support, says Kikuchi, and earlier this year a law was passed compelling construction companies to recycle their waste wood.

Ein also has a deposit system in place to recycle its own wood composite product, particularly the profiles used to make concrete forms.

Why wood fibre?

In his booth at the wood-plastic composites conference, Bill Crostic of Onaga Composites had a simple answer to the question of “Why all this interest in wood fibre?”. He pointed to a chart on the wall which demonstrated that wood fibre contributes to much higher flexural modulus than two other reinforcing fillers, calcium carbonate and talc, yet wood fibre has a lower specific gravity, leading to a lighter finished product.

Onaga Composites produces pelletized wood-plastic compounds for injection molding, and provides application support for molded WPC.

For those interested in injection molding WPC, the Society of Plastics Engineers, Ontario Section, will present a one-day workshop on the subject next spring. The event is set for Mar. 20, 2003 at the University of Toronto.

INTERESTED IN WPC?

Next year’s Progress in Woodfibre-Plastic Composites Conference will be held May 19-20, 2003, in Madison, WI. For details, contact the Forest Products Society, 608-231-1361, ex. 208, or www.forestprod.org. The proceedings of the 2002 conference are available for $50. Contact Val at viannaci@mmo.on.ca