Treesearch

Since the 1920s creosote has been used extensively in the United States for treatment of construction timbers, poles, and posts. However, creosote has the tendency to exude or bbleedc from some treated commodities, producing a tar-like covered surface. In the United States, creosote-treated products exhibiting cleaner dried surfaces and a reduced tendency to bleed have been achieved through reduction of the xylene-insoluble carbonaceous fraction in creosote. In Australia, pigment-stabilized creosote emulsion formulations have been designed and developed to blockc the oil phase within the...

At very early stages of decay of wood by basidiomycete fungi, strength loss can be measured from wood before any measurable weight loss. Therefore, strength loss is a more efficient measure of incipient decay than weight loss. However, common standard decay tests (e.g. EN 113 or ASTM D2017) use weight loss as the measure of decay. A method was developed that allowed progressive removal of samples so that all stages of colonisation and decay could be monitored by strength testing, weight loss determination and chemical analysis. Our results indicated that substantial and rapid decay (90%...

A recently discovered coupling agent, hydroxymethylated resorcinol (HMR), based on resorcinol-formaldehyde, can greatly enhance wood-to-epoxy resin bond durability in exterior applications. However, for HMR to be most effective, it needs to be prepared a few hours before it is applied to the wood surface. In this study, carbon-13 nuclear magnetic resonance (NMR) spectroscopy was used to monitor composition of HMR as a function of time to characterize which chemical groups are present in solution when HMR is applied. A quantitative assessment of formaldehyde-derived groups required the use...

Indoor air quality problems resulting from the emission of volatile organic compounds (VOCs) have become an issue of increasing concern. Emissions from building and furnishing materials, which are frequently constructed from particleboard and medium density fiberboard (MDF), are a potentially important contributor of indoor VOCs. In this research, VOC emissions from particleboard and MDF were measured in small (53-L) stainless steel chambers for 4 days. Samples were collected from 53 of the 61 U.S. mills that produce particleboard and MDF. Each mill identified the predominant tree species...

Biomechanical pulping of whole logs pretreated with Phlebiopsis gigantea was investigated in several studies using loblolly and red pine. Results from these studies showed P. gigantea was able to colonize 90 to 100% of the freshly cut logs after 8 weeks, with little variation between replicate treatments. Up to a 59% decrease in resinous wood extractives was observed in loblolly and red pine logs inoculated with P. gigantea as compared to noninoculated logs. Simonsa staining, used to evaluate cell wall changes in mechanically refined pulp fibers during biological pulping processes, showed...

Mycelial interactions and allozyme analysis for glucose&phosphate isomerase activity were used to evaluate compatibility of pairings of single spore isolates (SSIs) within and between Laetiporus restriction groups (LRGs). SSIs from six collections of LRG II were completely compatible. SSIs from four LRG III collections from western North America were completely compatible, but those from a fifth collection of LRG III, from Michigan, were only partially compatible with those from the western LRG III collections. LRG II SSIs were incompatible with LRG III SSIs, and SSIs of these LRGs were...

Conservation ethics and material shortages are stimulating interest in reusing wood products from demolished buildings and reusing entire buildings. As one of an anticipated series of reports coming from our research project titled, bNondestructive structural evaluation of wood floor systems in historic buildings,c this paper reports the results of determining the modulus of elasticity (MOE) of wood joists via static and vibration methods in both edgewise and flatwise orientations. Fifteen new southern pine joists (2-by 16- in. by 30 ft.) and nine joists (2- by 16- in. by 20 ft.) salvaged...

Wood [Indonesian pine (IP), Indonesian Jabon (IJ) and USA southern yellow pine (USP)] was either in situ polymerized with tributyltin acrylate (TBTA) or acetylated and then exposed to termite and fungal degradation both in laboratory tests and field exposure. The TBTA woods had an average weight percent gain (WPG) of 11% for IP, 12% for IJ, and 10% for USP. The acetylated woods had a WPG of 15-27% for IP, 16% for IJ, and 12-21% for USP. All levels of TBTA and acetylation treatments were effective against the brown-rot fungus Tyromyces palustris and the white-rot fungus Coriolus versicolor...

Disposal of preservative-treated waste wood is a growing problem worldwide. Bioprocessing the treated wood offers one approach to waste management under certain conditions. One goal is to use wood decay fungi to reduce the volume of waste with an easily managed system in a cost-effective manner. Wood decay fungi were obtained from culture collections in the Mycology Center and Biodeterioration research unit at the USDA-FS Forest Products Laboratory (FPL), Madison, Wisconsin, and from FPL field sites. The 95 isolates had originally been taken from at least 66 sites from around the United...

In this study, the effect of compression wood formation on the release rate of chromium, copper, and arsenic elements from red pine (Pinus resinosa Ait) was investigated. Wood blocks from red pine containing compression and normal wood portions were treated with a 1.0% CCA-C solution and were then allowed to fix at 23 * 2*C (74 * 4*F) for 0, 6, 24, 48, 96, 192, and 336 hours. After each fixation period, the blocks removed from the conditioning room were subjected to 336 hours of leaching. Less chromium and copper elements were released from the compression wood blocks. For chromium, the...