Treesearch

Kiln drying at high temperature may reduce warp in dimension lumber sawn from small-diameter trees. In this study, we examined the effect on warp of high drying temperatures in conjunction with top loading immediately after drying and after storage in typical conditions that result in further moisture loss. Eight-foot-long 2- by 4-in. (2 by 4) boards sawn from open-grown, 30- to 35-year-old, 9-in.-diameter at breast height ponderosa pine trees were kiln dried at three temperatures, 160°F, 230°F, and 280°F. Crook, bow, and twist were measured and compared. Total grade loss from exceeding...

The inadequate transportation infrastructure and undeveloped markets for sawmill residues in southeast Alaska are among the factors that limit the use of this forest resource. This study considers the potential use of sawmill residues to supply two bioenergy systems that would produce thermal energy for (1) community heating and (2) a lumber dry kiln in Hoonah, Alaska. The proposed community heating system would be a direct combustion system, burning approximately 1,450 green tons (1.315 green metric kilotons) of wood fuel per year to provide heating for seven centrally located buildings...

Timber rivet connections, originally developed for use with glulam construction, may be a viable option for use with structural composite lumber (SCL) products. Tests were conducted on small samples to assess the performance and predictability of timber rivet connections in parallel strand lumber (PSL) and laminated strand lumber (LSL). The test joint configurations were designed to exhibit rivet failures some combination of rivet yield and bearing deformation in the composite as opposed to wood failure modes, such as block-shear tear-out or splitting. Results suggest that per-rivet design...

This is a directory of companies involved in wood-framed building deconstruction, dismantling and reused building materials, with an emphasis on those that use, resell, and/or re-manufacture salvaged wood. Companies in this directory range in scope from those that carryout targeted building removals, such as historic barns, strictly for the purpose of harvesting the antique wood in these buildings, to companies that conduct residential and commercial demolition where the primary goal is building removal, and the recovery of materials is conducted opportunistically as a by-product. The bulk...

This study reviewed the literature on static and impact withdrawal of nails driven into the end grain of wood members. From this, an empirical relationship was created relating the specific gravity of the wood, the diameter of the nail, and the depth of penetration of the nail to the static withdrawal capacity of nails driven into the wood and withdrawn immediately. Areas of additional research are identified for end-grain nailing in wood members.

In recent years, computers, sensors, microelectronics, and communication technologies have made it possible to automate the way materials are tested in the field. It is now possible to purchase monitoring equipment to measure weather and materials properties. The measurement of materials response often requires innovative approaches and added expense, but the instrumentation vastly improves the quantity and quality of the data that can be obtained. Data on weather and materials can be linked to a computer system, either at the field site or through a communications link back to the...

There is a growing need to find a rapid, inexpensive, and reliable method to distinguish between treated and untreated waste wood. This paper evaluates the ability of near infrared (NIR) spectroscopy with multivariate analysis (MVA) to distinguish preservative types and retentions. It is demonstrated that principal component analysis (PCA) can differentiate lumber treated with CCA, ACZA, or ACQ preservatives. Furthermore, separation according to wood species and assay zone was also observed. Within the range of preservative concentrations available, partial least squares (PLS) regression...

A new procedure has been developed for the rapid continuous acetylation of lignocellulosic fiber. A limited amount of acetic anhydride is applied to the fiber before the fiber goes through a reactor at high temperature. The acetylated fiber is then stripped in a first step with superheated vapor of anhydride/acetic acid and, optionally, in a second step with superheated steam to both dry the fiber and convert any un-reacted anhydride to acid making separation of byproducts easier. Fiberboards made using the acetylated fiber were much more stable to dimensional changes in both high relative...

N,N-dimethyl amino carbinol catechol borate(1). N,N-dimethyl amino carbinol-4-methyl catechol borate(2), N,N-dimethyl amino carbinol-4-t- butyl catechol borate(3). N,N-dimethyl amino carbinol-2,3-naphthyl borate 4) were synthesized by refluxing boric acid and diol in DMF(N,N-dimethyl formamide). The borates were characterized by NMR. Wood impregnated with borate 1,2 or 4 after 2-week water leaching was able to prevent decay by a brown-and white-rot fungus. TGA showed that wood impregnated with borate 1 or 4 had a high char yield. DSC showed that the pyrolysis pathway of wood treated with...

The United States is a country with a vast forest resource, comprising about one-third of its total land area (or about 3 million square kilometers). As a result, wood is an important renewable resource and is widely used in many applications! including building construction, furniture, fuelwood, textile fabrics, organic chemicals, and paper manufacture. This wide usage generates a large volume of wood waste. Currently, nearly 63 million metric tons of this material is generated in the manufacture, use, and disposal of solid wood products each year. This paper describes the types and...