Manure fiber decking makes sense with no scent

An endless number of jokes could be made about a house made from manure-based products. But it’s no laughing matter.

MSU scientists are working on 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.

The composite materials would be made from a combination of plastic and manure fibers instead of the wood that makes up current fiberboard and other building supplies. The materials would be used to make products for use in the construction of everything from playground equipment to homes.

Putting manure into an anaerobic digester breaks down manure solids into a sterile, organic fibrous material and captures methane gas that can be used to produce electricity or sold to utility companies.

Charles Gould, MSU Extension educator, and Laurent Matuana, associate professor of forestry, knew that Iowa State University scientists had successfully combined the fibrous material from a digester with plastic to create composite materials and thought the idea had great potential for Michigan.

The two received a grant from the Michigan Biomass Energy Program and hired Alex Cook, an MSU undergraduate student, to develop two prototype products: a digester fiber/plastic composite product that could be used as decking and 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 such as strength, stiffness and internal bond.

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 said. "We have shown that value-added products can be successfully manufactured from digester fibers. Everything being equal, 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 seawalls.

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," he said. The most common question asked was about odor. Neither the fiber/plastic decking nor the medium-density fiberboard emits an odor.

So when will a contractor be showing up at the door to build a fiber/plastic backyard deck? As in most cases, the answers are tied to questions of time and money.

"We do not foresee any problems pounding holes or drilling into it at this point, but that’s one thing that still needs to be tested," Gould said, "and we need to find more money to do that."

Matuana concurred.

"There’s still a lot to be done. Properties related to nailability, screwability and humidity have not been investigated," he pointed out.