NRRI Scientist Matt Aro looks over the new thermal modification kiln installed in October.
The regional wood products industry was hit hard by the economic recession and a decline in housing construction. Many plants and sawmills closed. Demand for pulp and paper is down. But industry analysts are anticipating a 47 percent increase in housing starts from 2011 to 2013. They are also noting an increasing demand for engineered wood products. Combining a European technology with research on local wood species could provide opportunities to strengthen this vital industry.
The Natural Resources Research Institute received a $600,000 grant from the National Science Foundation to advance the science and understanding of thermal modification techniques using a pilot-scaled kiln installed in October. This grant will focus on improving regional wood species in engineered wood products, such as cross-laminated timbers and plywood. Thermal modification renders species like aspen, red pine and basswood usable for products that today are made from western trees like ponderosa pine. NRRI, at the University of Minnesota Duluth, will conduct the research with five industry partners.
"Our goal is to see regional wood species being used to make a new class of high-performance engineered wood products that excel in demanding environmental conditions," said Matt Aro, NRRI lead researcher on this project. "We’d put more local loggers and truckers to work hauling wood to the manufacturing plants, which would help our critical forest products industry, much of which has a rural base, get back on track."
The technology is a special heat technique that results in high-performing wood products. After modification, the wood is moisture resistant with decreased swelling and shrinkage in humid indoor and outdoor applications, and more resistant to rot-inducing fungi. It has exciting possibilities for construction applications, perhaps a better performing oriented strandboard. The process is in its infancy in the U.S. and NRRI’s new research kiln will be able to provide the data and validation to build the market.
The focus of the NSF "Partnerships for Innovation: Building Innovation Capacity" grant is to meet the needs of a high volume, engineered wood products market that is expected to grow quickly in the near future with the anticipated rebound in U.S. residential and commercial construction.
"Our native trees, especially hardwoods, have a problem with durability," said Pat Donahue, NRRI Program Director and project co-leader. "Basswood, for instance, would never be used as siding, but thermal modification can change that."
Donahue is working with Mathew Leitch at Lakehead University in Thunder Bay, Ontario, Canada, to develop North American industrial measures, performance standards and specifications for thermally modified wood.
The research results are based upon work supported by the National Science Foundation. However, the findings and conclusions are those of NRRI and do not reflect the views of the National Science Foundation.