Treesearch

Associations between plant roots and fungi are a feature of many terrestrial ecosystems. The genome sequence of a prominent fungal partner opens new avenues for studying such mycorrhizal interactions.

Pressure sensitive adhesive (PSA) contaminates post consumer waste impeding its processing and limiting the use of recovered cellulose fiber. An approach for reducing the impact of PSA on recycling operations is to redesign label systems to inhibit fragmentation of adhesive films. This results in residual PSA particles that are more easily removed from the process with conventional mill contaminant control equipment. In this presentation findings are reviewed from research aimed at the development of adhesive films that have little or no negative impact on recycling operations. Both...

Scanning probe microscopy (SPM) techniques have been used to investigate cellulose nanocrystal (CNC) surface chemistry and mechanical properties. Atomic force microscopy (AFM) was used to measure topography, stiffness, and pull-off force of CNC surfaces exposed to N2 atmosphere with a 0.1% relative humidity (RH). Changes in the stiffness and pull-off force as a function of location along CNC surfaces were used to assess the uniformity in mechanical properties and surface chemistry, respectively. This work showed that the contact geometry affected all measurements and needs to be accounted...

The accelerated test methods that distinguish between acceptable and unacceptable wood adhesives generally involve subjecting the bonded assembly to abnormally rapid and extreme moisture exposure or cycling. In the United States and Canada, these tests for moisture durability have been established, but selection of the appropriate test methods for the different service classes (extent of water exposure) is still being discussed in some cases. For establishing these standards, a better understanding of the information provided by these tests about the bondline durability is important. Most...

As an adherend, wood is structurally, chemically, and mechanically more complex than metals or plastics, and the largest source of this complexity is wood’s chemical and mechanical inhomogeneities. Understanding and predicting the performance of adhesively bonded wood requires knowledge of the interactions occurring at length scales ranging from the macro down to the molecular level of chemical interactions. This work investigates such interactions occurring at and below the micrometer range using nanoindentation.

To understand wood-plastic composites (WPCs) adequately, we must first understand the two main constituents. Though both are polymer based, they are very different in origin, structure, and performance. Polymers are high molecular weight materials whose performance is largely determined by its molecular architecture. In WPCs, a polymer matrix forms the continuous phase surrounding the wood component. These matrix polymers are typically low-cost commodity polymers that flow easily when heated, allowing for considerable processing flexibility when wood is combined with them. These polymers...

In February 2008, the Western Governors’ Association adopted a policy reaffirming the governors’ strong commitment to enhance and diversify the region's transportation fuels portfolio. The Strategic Assessment of Bioenergy Development in the West represents a major step in fulfilling that commitment and expands upon earlier work through WGA's Clean and Diversified Energy Initiative and the Transportation Fuels Initiative. The Bioenergy Assessment Team was formed to examine the potential for future development and to create a comprehensive framework to assess environmental, technical and...

Part 1 of this two-part article (published in the April 2008 issue of Paper360°) focused on the technology, operating and investment options for adding biorefinery capacity to existing pulp and paper mills in the U.S. Part 2 examines the finan­cial case for adding such capacity. This two-part analysis of the most feasible and effective routes for the pulp and paper and forest products industry to add energy, biofuels and bio­based chemicals to their existing product streams was conducted by the American Forest & Paper Association’s Agenda 2020 Technology Alliance. A full, detailed presentat...

McKay’s chi-square approximation for the coefficient of variation is type II noncentral beta distributed and asymptotically normal with mean n - 1 and variance smaller than 2(n – 1).

The chief technology officers of the American Forest & Paper Association’s Agenda 2020 Technology Alliance recently conducted an analysis of the most feasible and effective routes for forest products facilities in this country to add energy, biofuels and bio-based chemicals to their existing product streams. Considering that at least 21 billion gallons of the 36 billion gallons in the new federal Renewable Fuels Standard (RFS) are to be obtained from cellulosic ethanol and other advanced biofuels, the forest products industry—and pulp and paper mills in particular—is in a unique position...