Composite Products

Resource, Nov 2007 by Probyn, Laura

Offering the Agriculture Industry New Markets and the Construction Industry New Materials

There is no doubt about the endless number of jokes that could be delivered about a house made in part from manure. But it's no laughing matter. Michigan State University (MSU) Extension educator Charles Gould is on to an idea that may help farmers handle waste, provide them with a new source of income, and offer new, environmentally friendly products to the construction industry.

Gould has a vision for new lines of composite materials that use a combination of plastic and manure fibers, instead of the wood that comprises current fiberboard and other building supplies. His goal is to develop products for use in the construction of everything from playground equipment to homes.

It starts with a herd of cows

... a very large herd. There are more than 40,000 dairy cattle in Michigan's Allegan, Ottawa, and Kent counties, where rapid housing development has limited the acres available for manure application.

Farmers looking for alternatives to land application can choose to compost manure. Composting reduces its volume, makes it a more stable fertilizer source, and eliminates odor. Another option is to use an anaerobic digester, which breaks manure solids down into a sterile organic fibrous material and captures methane gas that can be used to produce electricity for the farm or sold to utility companies.

Gould read an article about how Iowa State University's biological composites lab successfully combined the fibrous material from a digester with plastic to create composite materials. He immediately saw the possibilities for western Michigan and contacted the lab director to request a visit and more information.

It takes a combined effort

Iowa State researchers were gracious, says Gould, and showed him what they were doing. We can do this at MSU, thought Gould who went to Laurent Matuana, an associate professor in the MSU Department of Forestry, who happened to already know the researchers at Iowa State. They developed a project proposal together.

Gould and Matuana submitted the proposal to the Michigan Biomass Energy Program. They received a small community education grant to hire undergraduate student Alex Cook to develop two prototype products: a digester fiber/plastic composite product that could be used as decking and, as well, a medium-density fiberboard. The two products were tested and compared to similar products made using wood fiber. The products made with fiber from a digester passed with flying colors, meeting or exceeding industry standards for properties in the areas of strength, stiffness, and internal bond.

It takes test after test

The digester fiber/plastic decking product performed better in tests against similar decking products made with wood/plastic. When two composite types were compared, the digester fiber/plastic decking product had properties that were superior to those of the wood product, including a darker color, which potentially could be more resistant to UV rays.

During the production process, the fibers intertwine and increase the strength of resulting composites. This offers an advantage in areas such as load-bearing capacity or material strength.

The properties of the medium-density fiberboard met or exceeded standard requirements. Matuana indicated the work confirms that value-added products can be successfully manufactured from digester fibers.

"Everything being equal," Matuana concludes, "the digester fibers are giving us much better properties than wood."

There are numerous possibilities for construction materials containing the digester fibers. Because the chemicals used in the production of pressure-treated wood have been shown to be harmful to human health, the U.S. Environmental Protection Agency has outlawed use of pressure-treated wood in playground equipment. Fiber/plastic "lumber" could take its place. Other uses might include products for siding, furniture, or lakefront sea walls.

Gould has already approached managers at two western Michigan home improvement retail chains to ascertain their feelings about carrying digester fiber/plastic decking or medium-density fiberboard made with the fibrous material from a digester. They indicated a willingness to purchase the product even though it was made out of fiber once found in manure, because they perceived the products to be green. The most common question asked was about odor. Thankfully, neither the fiber/plastic decking nor the medium-density fiberboard emits an odor.

It takes time and money

So when will a contractor be showing up at your door to build a fiber/plastic backyard deck or complete some other building project with composite products? As in most cases, the answers are tied to questions of time and money.

Gould does not foresee any problems pounding holes or drilling into the products at this point, but further testing is required. And, as always, more time and more money are required as well.

Matuana echos his colleague's sentiments. Properties related to nail-ability, screw-ability, and humidity have not been investigated.