Weyerhaeuser developing cellulose fiber reinforcement for plastics

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CHICAGO — Timber industry giant Weyerhaeuser Co. is getting into the plastics business, developing cellulose fiber reinforcement for plastics, which could be used in place of glass.

The initial product under the Thrive brand uses cellulose as a reinforcement in polypropylene and the first products are already in the marketplace, including a cutting board that has been a top seller at retailer Target, said Jorge Cortes, market development director cellulose fiber for Weyerhaeuser.

Cortes came to the Industrial Designers Society of America annual conference in Chicago Aug. 22-24 to discuss even more potential uses for the material.

"There are a couple of things that we're really excited about," he said during an interview. "Different techniques for using the product."

Weyerhaeuser, which is based in Federal Way, Wash., plants and harvests trees from multiple sites. The bulk of the wood goes into lumber. The wood pulp is also processed into cellulose fibers used in textiles and other products. Disposable diapers, for instance, use cellulose fibers.

The fibers are sold either in masterbatches for compounders or in already-blended pellets. Weyerhaeuser works with two resin suppliers to market the pellets. Americhem Inc. produces a version using virgin PP while Interfacial Solutions LLC of River Falls, Wis., makes pellets using recycled PP.

The cellulose-reinforced plastics are 8-10 percent lighter than a glass-filled product and are easier to process, with lower temperature and pressure requirements. Cortes said the pellets reduce molding time by 30-40 percent. In addition, the cellulose is not as tough on molds and equipment as glass reinforcement.

That does not mean the blend was easy to develop, he noted. Cellulose and PP normally repel each other, so Weyerhaeuser had to find the right recipe to use in the final blend.

For the EcoSmart cutting board by Architec Housewares, the PP is a translucent material, making it possible to see the cellulose flakes within the board. Other blends hide the filler, Cortes said.

In addition to the cutting board, the resin will be used for bowls, spoons and other housewares products. The auto industry is putting it into trunk components and interior trim.

Scott Clear, vice president of design group Intersection Inc. of San Diego, said his group has been investigating the resin's potential to boost eco-friendly qualities while also providing designers with the potential for a wider variety of styling.

"Glass doesn't want to do tight corners," he said. "You can't use it in a living hinge. With this, you're looking at more complex shapes."

In addition to ongoing product development, Weyerhaeuser is also looking at ways to take the resin into even greener territory. It hopes soon to launch a version using bio-based resins, which would mean the entire plastic part would be from renewable, natural sources, Cortes said.

"The wood product industry is not known for innovation, but Weyerhaeuser wants to change that," he said.

Cellulose and polypropylene are just the start. The company expects it can find even more markets for the reinforcement soon, using more resins, he said.