Treesearch

For many wood species, the grading of timbers [>76 mm (>4-in.) thick] has not changed in decades. Most timbers are still visually graded by methods that originated in the 1930s. Mechanical grading procedures used to accurately grade 38-mm (2-in. nominal) dimension lumber have not been adapted for use with timbers. Furthermore, the only reliable timber test data available for most softwood species were obtained near the turn of the 20th century, and no test data are available for hardwood timber. The lack of better grading procedures and test data makes it likely that current property...

We estimated the capital effectiveness of fiber loading in regard to producing lightweight high-opacity newsprint. Fiber loading enhances fiber bonding at increased precipitated calcium carbonate levels without significant loss in Canadian standard freeness or additional use of energy. We investigated the return on investment (ROI) for fiber loading precipitated calcium carbonate for a hypothetical 600 metric ton/day newsprint mill. Saving were obtained from substituting lower cost fiber-loaded precipitated calcium carbonate (FLPCC) for higher cost fiber, reducing grammage and drying...

This presentation provides a thought-provoking look at options for utilizing small- diameter wood to help reduce the widespread risk of catastrophic wildfire throughout the West while providing economic recovery of timber-depressed communities and sustaining viable forest products industry. Potentially viable utilization and marketing options are explored and current Forest Service small-diameter utilization research and technology transfer efforts are discussed. Specific points include effective utilization and marketing of underutilized and small-diameter material and evaluating potential...

The oil sorption capacities of cotton fiber, kenaf bast fiber, kenaf core fiber, and moss fiber were compared after refining, extraction, and reduction in particle sizes. The tests were conducted on diesel oil in a pure form. Cotton fiber showed the highest capacity, followed by kenaf core and bast fibers. Wetting, extraction, and reduction in particle size all contributed to the changes in sorption capacity. The most significant change was due to the reduction in particle sizes of cotton and kenaf bast fibers; however, the kenaf core was not affected. Usually, lignocellulosic fibers are...

This paper investigates the relationship between wood pH and the strength properties of fire-retardant-treated (FRT) plywood, as it is affected by fire-retardant (FR) formulations, processing variables, and extended high temperature exposure conditions. The objectives of this study were to (1) identify the effect of post-treatment kiln-drying temperature, followed by high temperature exposure, on wood pH; (2) identify the effect of various mixtures of FR components, followed by high temperature exposure, on wood pH; (3) determine if treatment effects on strength and pH are affected by...

Despite the rather random and heterogeneous nature of isolated lignins, many of their intimate structural details are revealed by diagnostic NMR experiments. 13C-NMR was recognized early-on as a high-resolution method for detailed structural characterization, aided by the almost exact agreement between chemical shifts of carbons in good low-molecular-mass model compounds and in the polymer (1, 2). Although this correspondence cannot generally be expected for proton NMR, lignin dimers and their counterpart units in the polymer also closely match proton NMR chemical shifts and coupling...

This report describes the history and current status of wood collections housed in the Center for Wood Anatomy Research at the Forest Products Laboratory, USDA Forest Service. The collections include the original Madison collection (MADw.) and the collection formerly housed at the Yale School of Forestry, Yale University (SJRw.) and the Chicago Field Museum (Fw.). General statistics are provided for MADw collection, including the Fw collection. Prospects and hopes for the future of xylaria at the Forest Products Laboratory are discussed.

Peroxidase/H2O2-mediated radical coupling of hydroxycinnamaldehydes produced 81O14-, 8-5-, 818-, and 5-5dimers as had been documented earlier (although we found that the 815-dimer is produced in its cyclic phenylcoumaran form at neutral pH). Spectral data from dimers and oligomers has allowed a more substantive assignment of aldehyde components in lignins isolated from a CAD-deficient pine mutant and an antisense-CAD-downregulated transgenic tobacco. The CAD-deficient pine lignin shows the typical benzaldehyde and cinnamaldehyde peaks at levels significantly enhanced over the corresponding...

During the course of restoring and maintaining forest ecosystem health and function in the western interior of the United States, many small-diameter stems are removed from densely stocked stands. In general, these materials are considered nonusable or underutilized. Information on the properties of these resources is needed to help managers understand when timber sales are a viable option to accomplish ecosystem management objectives. Pulp is a logical use for this small-diameter material. In this study, chemithermomechanical pulps (CTMP) were prepared and evaluated from lodgepole pine...

This paper describes the design, modeling, and testing of two portable timber bridges, each consisting of two noninterconnected longitudinal glued-laminated timber (glulam) deck panels 1.8 m (6 ft) wide. One bridge is 12.2 m (40 ft) long while the other bridge is 10.7 m (35 ft) long. The deck panels are fabricated in a unique double-tee cross section. The bridges exhibited linear elastic behavior in static bending tests. When actual lumber property data were used in transformed section and finite element models, the models overpredicted the stiffness of the bridge panels. The transformed...