New Treatment Plant Ushers in Next Century of Wood Preservatives

The Forest Product’s Laboratory (FPL) is pleased to announce the opening of a new, state-of-the-art pressure treatment facility to continue the tradition the laboratory has as an innovator in the field of wood preservation. The new, computer-controlled, vacuum and pressure, wood preservative treatment system includes five pressure vessels capable of treating material ranging from small test specimens, to large post and pole sections. Separate systems are maintained for water-based and oil-based preservative treatments.

FPL's Steve Halverson working in the pressure treatment facility.

FPL’s Steve Halverson working in the pressure treatment facility.

The new facility builds on the successes of the past to better the future of wood preservation.

The vast landmass of the United States was forged into a single nation through common ideology, shared destiny, and more than a little help from the railroad system. Supporting these tracks were thousands upon thousands of wooden railroad ties—but supporting these wooden ties were researchers at FPL.

Helping to keep the country’s trains rolling was the pressure treatment facility at FPL. One of the lab’s first objectives was to research better methods to make railroad ties last longer through pressure treatment methods.

Lumber, poles, posts and other outdoor wood products are usually treated with preservatives to prevent decay and insect damage. Pressure treatment is a process that forces a preservative deep into the wood structure. Without pressure treatment, only a thin outer layer of wood is protected.

The equipment can utilize pressures of up to 235 PSI (1620 kPa) and temperatures up to 250 degrees Fahrenheit (121 degrees Celcius). In addition, FPL’s facility features a unique design, allowing for small specimens to be treated in pans within the pressure vessels while the treatment solution is circulated and heated.

Now that the equipment is fully operational, researchers hope to find new ways to optimize the quality of preservative treatments.  By varying parameters such as steam, temperature, vacuum pressure, preservative type, and wood species, FPL hopes to identify cost-efficient treatment schedules that achieve thorough preservative treatment without damaging the wood structure.

The equipment is also critical to the evaluation of new types of preservatives. It can be used to prepare test specimens to study their resistance to biological degradation or leaching. Other applications include accelerated weathering, extracting of chemicals from wood, and elevated moisture simulations.

This new treatment facility has a much wider application than preserving railroad components. FPL invites collaboration with partners from industry, academia, trade associations, and other government agencies to take part in the next chapter of the laboratory’s history, ensure that the research is converted into useful technology, and help support the Forest Service’s mission of caring for the land and serving people.

Visit FPL’s website for more on our Durability and Wood Protection research.