“The Revolutionary Role of Wood in our Future”: USDA blog post highlights FPL research

The following is a post on the USDA blog highlighting research from the Forest Products Laboratory and the Northern Research Station. The original post can be seen here.

The Revolutionary Role of Wood in our Future

by David N. Bengston, Research and Development, USDA Forest Service
T3 Building in Minneapolis

The T3 Building in Minneapolis was constructed using cross-laminated timber, or CLT. Made from layers of wood crisscrossed and held together by fire-resistant glue, CLT is as strong as structural steel and greatly speeds up construction. (Photo credit: MGA | Michael Green Architecture, DLR Group; photo by Ema Peter; winner of a WoodWorks Wood Design Award)

Some people are just way ahead of their time. In the mid-20th century, when most people thought of wood as an archaic and low-tech material, Egon Glesinger foresaw the revolutionary role it would play in our future, described in his book The Coming Age of Wood.

Scientists in the Northern Research Station’s new Strategic Foresight Group developed a horizon scanning system to identify emerging issues and trends that could be game-changers. A theme that has emerged is the wave of amazing innovations in wood products that could prove Mr. Glesinger right.

For example, wood-based nanomaterials have been produced at the Forest Products Lab (FPL) for more than five years. This renewable, biodegradable material can be used to make computer chips, flexible computer displays, car panels, replacement tendons – for humans – and coatings that keep food fresh longer.

Tall wood buildings, or plyscrapers, are sprouting up across the globe today, built with cross-laminated timber (CLT) and based on research from the FPL and elsewhere. CLT is made from layers of wood crisscrossed and held together by fire-resistant glue. It is as strong as structural steel, greatly speeds up construction, and has a much lower carbon footprint than steel and concrete buildings.

Power-generating wood flooring is being tested at the University of Wisconsin-Madison, a collaboration between the University’s College of Engineering and the FPL. Made mostly from recycled wood pulp, the flooring is chemically treated to produce an electrostatic charge as people walk across it. The charge can power lights and smart building sensor networks, and charge batteries.

Students at the University of Wisconsin-Madison

Students generate electricity while they walk the floors of the student union building at the University of Wisconsin-Madison. Made mostly from recycled wood pulp, the flooring captures the energy of footsteps and turns it into usable electricity. (Photo by Adrienne Nienow)

The list of high-tech innovations in wood products goes on. Cellulose from wood pulp could be cheaper and stronger than petroleum-based polymers currently used for 3-D printing . Fabric made from wood fibers could revolutionize both the textile and forest industry. Wood nails can be driven into solid structural timber without drilling pilot holes. A new process chemically removes lignin from natural wood fibers to produce a transparent wood substitute for glass windows and solar cells. And biodegradable electronics could someday help curb the problem of e-waste.

These and many other marvels of wood product innovation could make the 21st century the century of wood , increasing demand for wood, leading to increased tree planting to meet demand, and the development of markets for wood currently lacking market value. Importantly, thinning overgrown forests with high fuel loads to supply these markets may also decrease wildfire risk.

Wood-based nanomaterials

Wood-based nanomaterials can be used to make electronic components like this one pictured, computer chips, car panels, replacement tendons, and coatings that keep food fresh longer. (US Forest Service courtesy photo)

Newest Forest Products Journal Features Adhesives: Many FPL Researchers Present

Adhesive-bond

Photomicrograph of an adhesive bond of two pieces of wood. The blue areas show the adhesive penetration into the wood structure.

The latest issue (Volume 54, No. 1/2, 2015) of The Forest Products Journal is all about adhesives. Featuring 10 selected articles addressing a theme of efficient use of wood resources in wood adhesive bonding research presented at the 2013 International Conference on Wood Adhesives in Toronto, Canada, we hear from several FPL scientists.

FPL has played an integral role in developing technical understanding of adhesives and setting product and performance standards by organizations such as the ASTM International (formerly American Society for Testing and Materials), American Institute of Timber Construction (AITC), APA–The Engineered Wood Association (APA), and the American Forest and Paper Association (AF&PA).

The first glue development research at the FPL in 1917 was to improve water resistance of the best glues available for manufacture of WWI aircraft components. At that time, FPL began to develop composites in an attempt to conserve our forests and make use of waste wood. Adhesives for housing, other buildings, timber bridges, and other structures has always been important.

In the Introduction to Special Issue: Wood Adhesives: Past, Present, and Future, Team Leader, Wood Adhesives, Forest Biopolymer Science and Engineering, Charles Frihart provides a comprehensive history and explanation of the important role that adhesives have played in the efficient utilization of wood resources.

Speaking about wood products, Frihart says: “Adhesives will continue to be a growing part of efficient utilization of forest resources. However, acquiring suitable wood resources will continue to be a challenge because of a diminished supply of high-quality wood and competition for wood from wood pellet and biorefinery industries. The challenges involve dealing with species that are not currently being used and with a greater mixture of species. More plantation wood could involve increased porosity and lower strength because of increased proportion of earlywood. The wood may also have increased or more variable moisture content as a result of efforts to reduce drying costs.

Wood products volume should continue to increase especially if engineered wood products replace other building materials for multi-story buildings and if there are sufficient housing starts. One challenge could be in bonding wood to other materials if glulam or laminated veneer lumber start using layers of stronger polymers or composites for greater strength. There also might be markets for bonding to modified wood, such as acetylated wood or heat-treated wood.”

Challenges in our changing forests and in changing construction practices will keep Frihart and his team busy for years to come as they find ways to use their adhesive research to adjust to change and best utilize our natural resources.

 

 

Cellulose Nanocrystals as Filler for Polymers

In a new publication, Supervisory Research Materials Engineer Gregory T. Schueneman reports on his research with cellulose nanocrystals (CNCs). CNCs are a class of renewable bionanomaterials with excellent mechanical properties that have attracted interest as filler for polymers. However, challenges associated with effective CNC dispersion have hindered the production of composites with desired property enhancements.

In Schueneman’s research, composites of polypropylene (PP) and low-density polyethylene (LDPE) with 5–10 wt% unmodified CNC are being produced for the first time with a solventless process, solid-state shear pulverization. Optical and electron microscopy revealed that the CNC dispersed very well and that degradation was strongly suppressed relative to composites made by melt mixing.

Field emission (FE) scanning electron microscope (SEM) images of as-received CNC at different weights.

Field emission (FE) scanning electron microscope (SEM) images of as-received CNC at different weights.

Taking thermal stability into account, this study has produced polyolefin/CNC composites with superior dispersion and property enhancements and has shown that CNC is an attractive and green filler for polymer composites. Over 50 million tons of plastic resins are used annually in the United States to manufacture products for a variety of end uses, including packaging, building materials, vehicles, furniture and furnishings, and electronics and electrical devices.

In this study, solid-state shear pulverization was used for the first time to produce composites of polyolefins and unmodified CNC. Microscopy and improved crystallization rate reveal excellent dispersion and suppression of CNC degradation within the polymer compared with composites made by melt mixing.These composites exhibit substantially greater stiffness, the greatest improvement ever reported for such composites made with unmodified CNC.

This study showed that CNC is an attractive and green filler for polymer composites.

The publication, titled “Cellulose nanocrystal/polyolefin biocomposites prepared by solid-state shear pulverization: Superior dispersion leading to synergistic property enhancements,” will be available online shortly. Cooperators include the USDA Forest Service Forest Products Laboratory, Madison, Wisconsin, and Northwestern University, Evanston, Illinois.

Wood-Based Composite Materials

Composites

Wood-based composite materials come in many shapes, sizes, and formats.

Wood-based composite materials come in many forms, including panel products, glued-laminated timbers, plywood, fiberboard, particleboard, and others.

Chapter 11 of the Wood Handbook provides a comprehensive overview of the types, composition, and manufacturing processes for wood-based composite products.

Composite materials, as described here, are any wood material bonded together, usually with adhesives. Wood-based composites are used for many structural and nonstructural applications for both interior and exterior purposes. The basic element for wood-based composites is the wood fiber, with larger particles composed of many fibers.

Chapter 11 is written by FPL research chemical engineer Nicole Stark and colleagues Zhiyong Cai, a supervisory research materials engineer, and the late Charles Carll, formerly a research forest products technologist. It is organized into three sections. The first covers conventional wood-based composite panels, summarizing common materials, adhesives, and additives. The second section covers several types of structural composite lumber, including glued-laminated (glulam) timber, parallel strand lumber, oriented-strand lumber and more. Wood-nonwood composites are discussed in the third section.

Many different composite materials and applications are on display at the fsWoodLab Flickr site.

Lights, Camera, Action! Discover Wisconsin Films at FPL

A film crew from Discover Wisconsin, a television program showcasing the many treasures of the Badger State, visited the Forest Products Laboratory this week as part of their America’s Dairyland series.  This series takes a look at Wisconsin’s largest and most important industry, the dairy industry.

A film crew from Discover Wisconsin interviews FPL engineer John Hunt.

A film crew from Discover Wisconsin interviews FPL engineer John Hunt, far right.

So, what does this have to do with forest products?

A key component of the dairy industry is, well, cows. And cows produce a lot of milk, but they also produce a lot of waste. That’s right, good old fashioned manure. FPL engineer John Hunt has found a way to make composite panels from cow manure mixed with other materials, such as recycled paper or cardboard.

As you can see, the Discover Wisconsin crew dug right in, getting down and dirty with this research project.

Discover Wisconsin host Eric Paulsen isn't afraid to get his hands dirty.

Discover Wisconsin host Eric Paulsen isn’t afraid to get his hands dirty.

But it’s really not so bad. The manure Hunt uses has gone through a process called anaerobic digestion, in which microorganisms break down biodegradable material in the absence of oxygen. The process reduces the manure to raw fiber (and produces energy as seen in this USDA video) which is not unlike other natural fibers used in composite products.

The resulting product is strong, lightweight, recyclable, biodegradable, and incredibly versatile. A similar panel product (sans manure) has found considerable success through FPL partner Noble Environmental Technologies (NET). NET produces a recycled panel product based on Hunt’s research called ECOR, which was recently touted for its use in building the first 100% sustainable Hollywood studio set.

We here at FPL had a great time with the Discover Wisconsin crew, and are excited to see the results. The episode is scheduled to air in June, so stay tuned…