Treesearch

The role of tree ring location and height within tree has a very significant impact on the properties of earlywood and latewood. This paper explores the role of earlywood and latewood properties on the dimensional stability of loblolly pine. Test results from isolated 1 mm by 1 mm by 30 mm pieces of earlywood and latewood show the differences in earlywood and latewood make different contributions to the stability of timber. Latewood is more sensitive to changes in moisture and shrinks longitudinally differently than earlywood. Influencing the proportion and properties of latewood can have...

Structural damage and potential health risks caused by wood decay and mold fungi in residential structures have been a major concern for homeowners, building contractors and insurance companies alike. The combined damage from decay fungi and mold claims exceeds several billion US dollars annually. Protection against decay and mold growth on wood is a critical economic concern for the building industry. An ideal compound for wood protection for interior applications must be nontoxic, hypoallergenic and able to provide long-term efficacy under high humidity. The objective of this study was...

This article focuses on considerations that need to be made when choosing products, other than stainless steel, to minimize corrosion of metals in contact with treated wood. With so many ?corrosion-resistant? alternative products on the market, it is important to know the fundamental principles of corrosion protection to make informed decisions when designing structures.

An instrumented Izod test was used to investigate the effects of fiber content, coupling agent, and temperature on the impact performance of kenaf fiber reinforced polypropylene (PP). Composites containing 0-60% (by weight) kenaf fiber and 0 or 2% maleated polypropylene (MAPP) and PP/wood flour composites were tested at room temperature and between -50 °C and +50 °C. At room temperature, kenaf greatly reduced energy to maximum load (EML) in reversed notch tests but had little effect in notched tests. MAPP improved all test values. At -25 °C, PP specimens changed from ductile to brittle....

Resinicium Parmasto is typified by Resinicium bicolor (Alb. & Schwein.: Fr.) Parm., (Hymenochaetales, Basidiomycota), a readily recognized and widely distributed corticioid, lignicolous species in the northern hemisphere. Five new species of Resinicium closely allied to R. bicolor from the Caribbean region are described and illustrated: Resinicium conferturn Nakasone, sp. nov., Resinicium monticola Nakasone, sp. nov., Resinicium mutabile Nakasone, sp. nov., Resinicium rimulosum Nakasone, sp. nov., and Resinicium tenue Nakasone, sp. nov. In addition, R. bicolor and Resinicium friabile...

Development of synergistic biocides to protect wood in interior applications has been of particular interest since the recent increase of indoor mold infestations. Many products have been developed to address the recent influx of indoor mold infestations. Researchers must emphasize the use of environmentally benign chemicals due to the need for safety of human occupants. Some typical strategies employed include one or more of the following: naturally occurring antimicrobial or insecticidal chemicals, synergistic combinations of chemicals, chemicals with known performance (and previous EPA...

Southern pine solid wood and wood fiber were reacted with acetic anhydride to various acetyl weight gains. The equilibrium moisture content (EMC) was determined on these specimens at 30%, 65% and 90% relative humidity (RH) and 27 °C. A standard soil block decay test using the brown-rot fungus Gloeophyllum trabeum was performed and weight loss calculated. Two possible mechanisms have been proposed to explain the resistance of attack of brown-rot fungi on chemically modified wood. One involves the lowering of the cell wall moisture level below that needed for fungal attack. The second...

Interest in the use of nanoparticles of iron, titanium, aluminum, and zinc oxides in transparent coatings for wood is increasing. Such nano-composite coatings have the potential of not only preserving the natural color of the wood, but also stabilizing the wood surface against the combined degradative effects of sunlight and moisture. The nanoparticles can be used as additives to coating formulations or deposited directly as thin films on a substrate. Thin film deposition can be accomplished by plasma-enhanced chemical vapor or by sol-gel deposition. This paper describes sol-gel deposition...

The prediction of the elastic modulus of short natural fibre hybrid composites has been investigated by using the properties of the pure composites through the rule of hybrid mixtures (RoHM) equation. In this equation, a hybrid natural fibre composite assumed as a system consisting of two separate single systems, namely particle/polymer and short-fibre/polymer systems. However, there is no interaction between particles and short fibres. Polypropylene was used as the polymer matrix and 40-80 mesh kenaf fibre and 60-100 mesh wood flour were used as the fibre and the particulate reinforcements...

For softwood lumber producers 2006 was an ?interesting? year, but mostly in the Chinese proverbial sense of the word. This is illustrated by the top U.S. producer, the Hampton Affiliates sawmill in Willamina, Ore. It receives double kudos for remaining the top producer, but also for being the one among the top 30 that cut back the most, thus doing its share to keep a badly oversupplied market balanced. Its 2006 total of 426MMBF was down 12% from its previous year?s total. Overall, the 200 mills for which we had both 2005 and 2006 data showed a drop in production of almost 6%. Capacity...