Borate and Adhesives: Can They Work in Harmony?

Scientists at the Forest Products Laboratory (FPL) are continually honing their expertise on all things cross-laminated timber (CLT) and this time, they’re digging deeper to learn how preservatives can protect and enhance this handy material.

Borate, an environmentally friendly preservative, has been proven effective in shielding decay and termite damage, while also protecting CLT’s aesthetic appearance, making it a suitable treatment for interior residential applications. But researchers from the Lab’s Durability and Wood Protection Research unit and Michigan State University are wondering how far borate can go if a sticky situation comes into play.

The project, which began in January 2018, aims to discover how well borate can protect CLT against termites, fungal decay and fire when it teams up with adhesives.

Fire test samples. Top, Class I fire-retardant coating; bottom, borate-treated spruce.

Researchers are currently studying how borate will change the surface properties of CLT.  They plan to compare how adhesive formulations interact with CLT that is treated with borate with that which is left untreated.  The wood will be analyzed using various spectroscopy methods. After measuring the adhesive properties of both polyurethane and phenolic glues, researchers will construct small-scale samples of CLT from borate-treated wood and a range of adhesive formulations.  The strength of these formulations will be tested when they are applied to a selection of treated and untreated CLT.

A borate spray solution will also be developed and applied to various CLT samples, where it will then be observed under conditions like fire, termites, and fungal decay. By the conclusion of the project in 2020, researchers hope to further understand how preservative-treated CLT performs under stress, especially when exposed adhesive is involved.

To learn more about this study and how borate and adhesives coexist, read the full Research in Progress report.

New Videos of Blast Tests Available

New video footage has been released of blast testing performed on cross laminated timber (CLT) structures, and it’s quite a sight to see.

The Forest Products Laboratory, in cooperation with WoodWorks and the Softwood Lumber Board, led a second round of live blast testing in 2017 at Tyndall Air Force Base in Panama City, Florida.

The charges in the videos were large enough to potentially cause lethal injury, and the structures survived. The objective of these studies was to demonstrate the capability of CLT structures to resist airblast loads, thereby allowing the military to incorporate mass timber materials like CLT into their construction projects.

You can read more about the study here, and see all the blast test videos on the WoodWorks YouTube channel.

Forest Service Leaders Convene at FPL

The Forest Service’s Combined Eastern Leadership Team, with members from the Forest Products Laboratory (FPL), Northern Research Station (NRS), Region 9, and Northeastern Area, State and Private Forestry gathered at FPL this week for the sixth year running.

Forest Service Interim Chief Vicki Christiansen addressed the group on a wide range of issues Wednesday, including the recent fire-funding fix, the One USDA initiative and the expectation of leaders as the Forest Service moves forward with important Workplace Environment efforts.

“This is always one of the highlights of the year, and we really do model the concept of one Forest Service,” said Tony Ferguson, director of FPL and NRS. “It was just a really great week.”

Other themes for the week included discussions on combining resources to achieve shared goals, environmental analysis and decision making, conflict management and prevention, and congressional awareness and interactions.

Meeting participants tour FPL’s pressure treatment pilot plant.

The Forest Service’s Middle Leader Program also spent the week at FPL and joined the leadership team all day Wednesday. Participants from both groups toured the Lab as part of their visit.

“I am just so gratified with the ease in which everybody in all three mission areas interacts with each other,” said Kathleen Atkinson, Eastern Region Regional Forester. “It is just wonderful to be a part of this.”

Wood Heat Stakeholders Gather, Talk Opportunities and Urgency at Heating the Midwest

(Article by Tim Portz, Forge Content)

Heating the Midwest, an annual conversation and roundtable about growing the role of wood heat in the Upper Midwest was held last week at the Black Bear Convention Center in Carlton, Minnesota.

Kicking off the Heating the Midwest conference. (L to R: Brian Brashaw, Program Manager, Forest Products Laboratory; Tim Portz, Executive Director, Pellet Fuels Institute; Gregg Mast, Executive Director, Clean Energy Economy MN)

This year’s conversation carried an increased sense of urgency with the news of the closure of three large biomass power plants in Minnesota on everyone’s minds. Benson Power in western Minnesota and Laurentian Energy Authority’s two plants located in Hibbing and Virginia will be shutdown, and with their closure the demand for nearly 500,000 green tons of woody biomass in the area will disappear.

Set against that backdrop, this year’s Heating the Midwest agenda worked to highlight wood biomass thermal deployments that work despite an economic environment of historically low fossil fuel prices while also looking toward projects with a realistic chance at gaining traction and stepping into the void created by the Benson and Laurentian Energy closures.

“The forest products industry is absolutely vital to the rural economies of Minnesota, Wisconsin and Michigan,” said Brian Brashaw, a longtime Heating the Midwest steering committee member and Program Manager for the USDA Forest Products Laboratory. “A healthy forest products sector adds value to woody biomass of all sorts and when demand for lower value material goes away, it reverberates throughout the supply chain.  Healthy forests and industry need markets for all harvest products.”

Brashaw’s comments were supported on Thursday morning when Scott Dane, the Executive Director of the Associated Contract Loggers & Truckers of Minnesota took the stage. For Dane and his membership, these plant closures will significantly reduce the available work, straining a vital piece of the forest products supply chain.

Conference participants on tour. Sawmill residues seen here are being used for biomass heating.

For an audience hungry for some good news, a highlight of the conference was a joint presentation delivered by Terry Nanti the General Manager at Duluth Energy Systems and Lee Torrens, President of Enysn Fuels, Inc. The presentation walked the audience through the decision making process that Duluth Energy Systems used to make a decision to transition the city-owned steam plant to a biomass-based feedstock. As part of a broader modernization effort, the city is planning to begin burning Enysn’s renewable fuel oil (RFO) product. While the first volumes of RFO burned at Duluth Energy will be manufactured at Ensyn Fuel’s refinery in Canada, Torrens delighted the audience by expressing his continued interest in Minnesota as a potential site for Ensyn’s first U.S.-based production site.

“Our region is blessed with abundant supplies of renewable biomass from our fields and forests,” said Gregg Mast, executive director of Clean Energy Economy Minnesota. “Identifying market applications for these materials is critical for retaining and expanding supply chain jobs and spurring rural economic development.” Throughout the event, Brashaw and other longtime Heating the Midwest steering committee members asked the audience to join the conversation about what Heating the Midwest should be dedicating its time and energy to. A common theme from attendees was that while difficult, it was imperative to take the message of modern wood heat to a new audience of city planners, county officials, state policy makers and architects and engineers.

The conference also featured a biomass heating tour in Northeast Minnesota, making important connections between resource supply from harvesting and manufacturing residues and modern, efficient and clean heating systems.  Recently installed biomass heating installations at the Northeast Regional Corrections Center and the Fond du Lac Band of Lake Superior Chippewa were featured.

 

Southern Exposure: Long-Term Field Testing of Wood Protectants

When researchers are looking to evaluate the performance of wood protectants, the harsher the environment the better. Which is why Forest Products Laboratory (FPL) researchers put specimens to the test in the Harrison Experimental Forest (HEF) in Saucier, Mississippi, and have been doing so for 80 years.

Generations of FPL researchers have used the HEF field site for sub-tropical field testing. Here Oscar Blew is rating posts at the HEF (1950’s).

Located about 35 miles north of the Gulf of Mexico, this sub-tropical field site receives about 60 inches of rainfall a year and has a mean temperature of 68 degrees Fahrenheit. The wood decay hazard in this area is rated “severe” according to the American Wood Protection Association Use Class Rating System and there is significant subterranean termite activity. When in ground contact, untreated wood rarely lasts 12 months in the HEF, to which researchers respond “challenge accepted.” Continue reading