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A better understanding of the relationship between wood properties and solution uptake during pressure treatment could lead to improvements in treatment quality and more efficient use of preservatives. In this study several years of treatment data representing a range of wood species, charge conditions and preservative formulations were analyzed to evaluate the relationship between wood density and solution uptake. Density and solution uptake (weight gain per unit volume) were determined for individual specimens in each charge. The analysis revealed that in many cases there was little or...

Because pressure-treated wood is perceived as economical and relatively easy to install, federal, state and local government agencies sometimes utilize treated wood for industrial-type applications. When these agencies have questions or concerns about treated wood they may make inquiries to the US Forest Products Laboratory. These inquiries provide an indication of topics where there may be a lack of understanding and a need for more information about industrial treated wood products. The most common inquiry involves types of treated wood available and the appropriateness of a treatment...

A preliminary study to evaluate naturally durable wood species in an above ground field trial using Gas Chromatography-Mass Spectrometry (GC-MS) detected differences in fatty acid extractives between species and within the same species over time. Fatty acids were extracted with chloroform: methanol mixture then methylated with sodium methoxide and fractionated using solid phase extraction columns. Fatty acids were identified, quantified with known standards, and compared between wood species. Future analysis of exposed specimens will determine longevity of extractives and correlate changes...

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites (WPCs) incorporated with different levels of boron compounds, borax/boric acid (BX/BA) (0.5:0.5 wt %) and zinc borate (ZB) (4, 8, or 12 wt %) were investigated. The effect of the coupling agent loading (2, 4, or 6 wt %), maleic anhydride-grafted PP (MAPP), on the properties of the WPCs was also investigated. Incorporation of the fire retardants (FRs) into the WPCs decreased the physical and mechanical properties as compared to the WPCs without FR. The FR treatments had little impact on the...

A combined heat, moisture, and corrosion model is presented and used to simulate the corrosion of metal fasteners embedded in solid wood exposed to the exterior environment. First, the moisture content and temperature at the wood/fastener interface is determined at each time step. Then, the amount of corrosion is determined spatially using an empirical corrosion rate model and the inputs of the first step. The result is a corrosion profile along the length of the fastener generated by summing the corrosion depths determined at each time step. We apply the combined model to predict the...

The influences of temperature, heating rate, purge gas type, and flow rate on the yield of chars produced from pyrolyzing southern pine chips were investigated. Pyrolysis temperatures were between 450°C and 1,000°C, with heating rates of 0.5°C/min, 1.0°C/min, 10°C/min, 30°C/min, 50°C/min, and 100°C/min. Purge gases, nitrogen (N2), hydrogen (H2) and N2-H2, mixture (10% H2), were used at flow rates from 100 to 1,000 mL/min. Pine char yield decreased as temperature, heating rate, or purge gas flow rate increased. Two regions with significantly different decrease rates of pine char yield can...

This study investigates the effects of alkaline copper quaternary (ACQ) preservative treatment and of plywood glue lines on resistance-based moisture content (MC) measurements. Moisture meter readings using stainless steel screws as electrodes were acquired over a range of moisture conditions in Southern Yellow Pine (SYP) lumber and plywood. Calibration equations are presented for predicting gravimetric MC from meter readings taken in SYP lumber and SYP plywood with or without ACQ treatment. These corrections assume that the meter has been set for SYP. Correlation equations are also...

The objective of this report is to summarize the scientific findings that support the environmental and economic benefits of using wood and wood products in green building construction. Despite documented advantages in many peer-reviewed scientific articles, most building professionals and members of the public do not recognize wood as a renewable resource or the role that efficient wood utilization plays in mitigating climate change and promoting healthy forests. Research and development of wood products and building systems also are lagging behind that of other materials. Both scientific...

The brown-rot fungus, Fibroporia radiculosa, has been included in numerous research studies because many isolates of this fungus demonstrate an unusually high tolerance to copper. This fungus has undergone several recognized changes in taxonomic nomenclature, and through DNA technology, scientists have correctly identified isolates that had been misidentified microscopically. Fibroporia radiculosa is not uncommon. In fact, the isolation and prevalence of Fibroporia radiculosa has been documented by mycologists since the 1930s, but the mechanism of copper tolerance remains a mystery. Here,...

This report covers stake test results primarily from Southern Pine 2- by 4- by 18-in. sapwood, treated by pressure and nonpressure processes and installed by Forest Products Laboratory employees and cooperators in decay and termite exposure sites at various times since 1938 at Saucier, Mississippi; Madison, Wisconsin; Bogalusa, Louisiana; Lake Charles, Louisiana; Jacksonville, Florida; and the Canal Zone, Panama. Also included in the tests at Saucier, Mississippi, are smaller pine stakes and those of treated and untreated plywood, particleboard, modified woods, laminated paper plastic,...