Treesearch

The purpose of this study was to clarify the effects of composite processing and moisture sorption on laboratory fungal resistance of wood-plastic composites. A 2-week water soaking or cyclic boiling-drying procedure was used to infuse moisture into composites made from high-density polyethylene filled with 50 percent wood flour and processed by extrusion, compression molding, or injection molding. Extruded composites absorbed the most moisture; compression-molded composites absorbed less than did extruded composites, and injection-molded composites absorbed the least. Although more...

Bioprocessing CCA wood waste is an efficient and economical alternative to depositing the waste in landfills, especially if landfill restrictions on CCA waste are imposed nation wide. We have developed bioremediation and degradation technologies for microbial processing of CCA waste. The technologies are based on specially formulated inoculum of wood decay fungi, obtained through strain selection to obtain metal tolerant fungi. Two strains of Meruliporia incrassata and two strains of Antrodia radiculosa were selected for capacity to degrade CCA wood, thereby reducing the waste volume....

Mushroom-producing white-rot fungi can be used to convert woodwaste into gourmet and medicinal mushrooms. White-rot fungi do not always readily colonize on conifer wood because of its extractives content. This study evaluated the resinous extractive content of loblolly pine (Pinus taeda), ponderosa pine (Pinus ponderosa), and an unknown species of southern yellow pine before and after treatment with the extractive-degrading fungi Aureobasidium spp., Ceratocystis spp., and Ophiostoma spp. Fungal treatment removed 70 to 99.9 percent of extractives. Scanning electron microscopy showed heavy...

Southern yellow pine sapwood stakes and blocks were treated with the sodium salt of the calcium-precipitating compound N’N-hydroxynapthalimide (NHA) and leach tested for 2 weeks using the American Wood-Preservers’ Association (AWPA) standard. Leacheates were measured for NHA using a microplate optical density ultraviolet reader, and leach rates were estimated for tap water, distilled water, and seawater. The percentage of NHA lost from blocks ranged from a low of 5.0 percent for seawater to 26.4 percent for distilled water. Clearly, higher inorganic ion concentrations in the leaching...

Moisture sorption in fiber-thermoplastic composites leads to dimensional instability and biological attack. To determine the pick up of moisture this type of composite, aspen fiber/polypropylene composites were made using several different levels of aspen fiber (30 to 60% by weight) with and without the addition of a compatibilizer (maleic anhydride grafted polypropylene, MAPP). These composites were tested using short and long term water soaking, boiling water, cyclic liquid water and oven drying, and under various relative humidity conditions. As the level of fiber increased in the...

Chromated copper arsenate (CCA) treated wood has been used extensively in outdoor applications. The Environmental Protection Agency (EPA) and CCA producers recently reached an agreement to limit future use of CCA for some types of applications. One area of concern is the long-term accumulation of leached CCA in soil adjacent to treated wood structures. Interpreting soil measurements adjacent to in-service structures is difficult. The original treatment may be unknown, and there may be little historical data to indicate whether the site was previously exposed to contamination from constructi...

The growth of pulp and paper mills in the US from 1970 to 2000 depended mostly on size and age. Mills grew according to Gibrat’s law, and post-1970 mills grew faster than pre-1971 mills. Mills stopped growing at approximately 22 years of age. But most mills survived beyond that, thus growth was not necessary for survival, but characteristic of the early phase of the mill life cycle. Less integrated mills grew slower. So did more specialized mills and more so if they produced mostly paper. Mill location was uncorrelated with growth, but location mattered indirectly by facilitating or...

We analyzed the physical properties of wood chips incubated with Ceriporiopsis subvermispora and cultural parameters of biopulping incubations of Phanerochaete chrysosporium and C. subvermispora. Dynamic mechanical analyses indicated a reduction in the modulus of elasticity (MOE) and loss modulus of spruce during the time where the biopulping energy savings effect takes place. The data from measurements of the MOE at different moisture contents indicated the fiber saturation point (FSP) of spruce increased from 29% to 42% during biopulping. Chips were made into pulp, which was washed, and...

During the twentieth century the Jewish National Fund (JNF) planted more than 200 million trees in Israel. These newly developing forests provide an opportunity to study the development of fungal communities. This study was initiated to quantify taxa richness and abundance of wood-inhabiting corticioid and polyporoid fungi (including heterobasidiomycetes) in eight even-aged forests dominated by Pinus halepensis (Aleppo pine). Four of the stands were 5-15 years of age, and four were 30-45 years of age. Of the four younger stands, three were previously planted to P. halepensis. Each stand...

A method is suggested for estimating additions to carbon stored in harvested wood products (HWP) and for evaluating uncertainty. The method uses data on HWP production and trade from several decades and tracks annual additions to pools of HWP in use, removals from use, additions to solid waste disposal sites (SWDS), and decay from SWDS. The method is consistent with IPCC guidance for estimating emissions from SWDS. Uncertainty is postulated in the form of probability density functions for 14 variables, using Monte Carlo simulation.