Adhesives Magazine

New Technology Underway to Develop Bark-Based Adhesives

February 28, 2001


Tree bark may no longer be viewed as a low-value by-product of the wood-products industry. Louisiana-Pacific Corp., a supplier of building products in Portland, along with its partner, Ensyn Group Inc., Boston, are in the process of unlocking the high-value chemicals stored in bark to develop natural adhesives, or resins, that can be used in the production of structural building materials. Ensyn develops industrial bio-based fuels and chemicals used in the commercial production of resins and food flavorings.

Bark accounts for roughly 15 percent of the raw materials taken into an average wood-products facility. It is commonly used today as landscaping mulch, or low-grade thermal fuel. For years, scientists have attempted to “crack” the fundamental chemicals in bark by using processes similar to those developed at petroleum plants.

Department of Energy Offers Funding

Not until recently has Ensyn developed the technology capable of extracting the naturally occurring chemicals found in wood and experimentally proving that they can be used in the production of building materials. The U.S. Department of Energy has granted Louisiana-Pacific, Ensyn and two major U.S. resin suppliers $1.4 million to develop bark-based adhesives for use in the production of structural building materials, including oriented strand board and plywood. This bark-to-resin program will help offset the wood-products industry’s dependency on petroleum-based resins and produce a “char” that can be converted to activated charcoal, or burned as a high-efficiency fuel.

The funding is part of former President Clinton’s 1999 Bio-Based Product and Bioenergy Initiative designed to triple the U.S. production of fuels and chemicals from biomass by 2010. The Energy Department’s grant will be matched by funds from Louisiana-Pacific and Ensyn.

According to Robert Graham, Ensyn president and CEO, “Bark holds great promise as a raw material for producing a less-expensive substitute to the petroleum-based adhesives traditionally used in building products.”

Natural Resins Offer Many Benefits

“Ensyn is clearly a leader in demonstrating the commercial feasibility and cost-effectiveness of extracting chemicals found naturally in wood and using them to produce quality products,” said Warren Easley, Louisiana-Pacific’s vice president of Technology and Quality. “There is a wide array of potential benefits to using bark-based adhesives, which range from pollution reduction to keeping the cost of building products down for our customers.”

Louisiana-Pacific’s Advanced Technology Center, created two years ago to bring more-focused attention to innovation in building materials, will take a lead role in the effort to develop natural resins. The research and development conducted by Ensyn and Louisiana-Pacific will focus on demonstrating the commercial feasibility of producing large quantities of bark-based adhesives at several test sites. The result of applying these types of new techniques to the production of building materials will lower costs for consumers and, in the case of the bark-to-resin project, reduce dependence on petroleum products, which encourages efficient conversion of biomass materials. An environmental assessment of any new technology developed will be conducted, and an approved certification laboratory will certify all products produced with bark-based adhesive.