Treesearch

Over 1.9 × 106 housing units are constructed in the United States in 2004. On a volume basis, wood products comprise almost 80% of all materials used in residential housing. It is estimated that over 7 × 109 m3 of lumber have gone into structures in the United States over the last century. Half of the wood products now used in construction are engineered wood composites. Employing nanotechnology within the forest products industry could result in previously undreamed of growth opportunities for bio-based products. Nanotechnology will result in a unique next generation of wood- based...

Decay can cause significant damage to high-value hardwood timber. New nondestructive evaluation (NDE) technologies are urgently needed to effectively detect incipient decay in hardwood timber at the earliest possible stage. Currently, the primary means of inspecting timber relies on visual assessment criteria. When visual inspections are used exclusively, they provide no indication of the extent of internal deterioration that may exist in timber. In this study, time-of-flight, stress-wave tomography, and micro-drilling resistance methods were investigated for locating incipient decay in...

Finite element analyses using ANSYS were conducted on orthotropic, polygonal, wood laminated composite poles subjected to a body force and a concentrated load at the free end. Deflections and stress distributions of small-scale and full-size composite poles were analyzed and compared to the results obtained in an experimental study. The predicted deflection for both small-scale and full-size composite poles agreed well with the experimental measurement. Maximum stress of a cantilever pole was in parabolic areas of the top and bottom skins near the ground line. The finite element model...

Forest Products Laboratory (FPL) assistance was requested in mechanical grading of logs for two cable suspension bridges intended for pedestrian use in parks near Missoula, Montana. Two hundred ninety two lodgepole pine logs were obtained from a beetle-killed stand near Elk City, Idaho, by Porterbuilt, Inc., of Hamilton, Montana, and machined (dowelled) to a constant diameter of 6 in. The logs were visually graded by Timber Products Inspection, Inc., of Longview, Washington, and mechanically graded by FPL staff using procedures developed in previous research. Of the logs selected, 236...

In recent years, public concern about indoor mould growth has increased dramatically in the United States. In this study, lactic acid bacteria (LAB), which are known to produce antimicrobial compounds important in the biopreservation of food, were evaluated to determine if the same antimicrobial properties can be used to inhibit mould fungi that typically colonize wood. Based on biomass measurement, cell-free supernatants from Lactobacillus casei subsp. rhamnosus and Lactobacillus acidophilus grown in deMan Rogosa Sharpe (MRS) broth inhibited 95-100% growth of three mould fungi and one...

There is increasing interest in preservative pressure-treatment of framing lumber to prevent attack by decay fungi and insects. However, the Spruce– pine–Fir species group that is often used in framing construction can be difficult to penetrate with preservatives. We compared solution uptake and penetration of boron and copper from a borax–copper (BC) preservative to that of boron in a disodium octaborate tetrahydrate (DOT) treatment and copper in a chromated copper arsenate (CCA) treatment. For all wood species, average solution uptake was consistently greater with the DOT solution than...

The elastic properties of earlywood and latewood and their variability were measured in 388 specimens from six loblolly pine trees in a commercial plantation. Properties measured included longitudinal modulus of elasticity, shear modulus, specific gravity, microfibril angle and presence of compression wood. Novel testing procedures were developed to measure properties from specimens of 1 mm=1mm=30 mm from earlywood or latewood. The elastic properties varied substantially circumferentially around a given ring and this variation was nearly as large as the variation across rings. The elastic...

Nanotechnology is defined as the manipulation of materials measuring 100 nanometers or less in at least one dimension. In addition, nanomaterials must display unique properties and characteristics that are different than their bulk properties. At the 1-nanometer (nm) level, quantum mechanics rules, and at dimensions above 100 nm, classical continuum mechanics, physics, and chemistry dictate properties of matter. Between 1 and 100 nm, a hybrid exists, and interesting things can happen. Mechanical, optical, electrical, magnetic, and a variety of other properties can behave quite differently,...

As worldwide demand for timber and bio-fiber resources grows, sustainable resource management and industrial utilization must collaborate to develop a shared vision for both long-term sustainable management of forest and bio-resources and sustainable economic development. Engineered wood- and bio-composites offer a tool that can both achieve resource sustainability and meet user needs in our ever-more affluent societies and for our growing populations [1]. Biocomposite technology provides a tool for resource managers because it can add value to low- or no-value fiber resources and thereby...

The bending properties of Korean pine (Pinus koraiensis) treated with a newly formulated guanylurea phosphate (GUP) fire retardant were evaluated. The chemical processing method used to formulate this fire retardant(called FRW) results in an organic phosphate fire-retardant system with less acidic pH and fewer impurities. The fire-retardant chemical studied consisted of high purity GUP, boric acid (B), and a minor amount of additives. The clear specimens of pine treated with FRW were either air- dried after treatment or kiln-dried at 70°C and were then subjected to various durations of a...