The responsible usage of water by facilities that rely on wet log storage in the southern United States has become an issue of great importance as restrictions on water usage have grown in recent years. In order to learn about the dynamics of moisture content in wet-stored logs over time, it is necessary to conduct continuous monitoring of log piles. Time domain reflectometry (TDR) is a method that current research has shown to have potential for use in this area. In this study, TDR probes of three lengths (75, 100, and 125 mm) were systematically inserted into 39 saturated bolts of Pinus taeda L., and both TDR and moisture content measurements were taken nine times over a period of 16 days as the bolts air dried. The samples were then oven dried, and measurements were taken three more times during that process. TDR readings from the 125-mm probes had the strongest relationship (R2 = 0.9426) with moisture content measurements. This result indicates TDR readings are sufficiently correlated with moisture content to accurately predict moisture variation over time and can be used to learn how water application and other factors affect the moisture content of wet-stored logs.
The impacts on drying behavior of basic density, initial moisture content, percentage and position of heartwood, ring count, rings from the pith, growth ring angle, and earlywood and latewood coverage on board faces were investigated for western hemlock (Tsuga heterophylla) lumber. Mathematical relations for the effects of wood properties and board geometric features related to position within its parental log were developed to predict the drying rate at four moisture content levels for drying temperatures of 80°C and 115°C. These relations were used for simulating wood drying as well as for predicting drying times of individual boards, which were used as a criterion for sorting green boards prior to entering their properties in the drying simulation. Drying rate was affected by basic density, initial moisture content, percent heartwood, and growth ring angle at 80°C and only initial moisture content at 115°C. Presorting into two groups based on these wood properties reduced the standard deviation of the final moisture content distribution by 40 percent.
Antifungal Activity of Organic Extracts from Juniperus virginiana Heartwood against Wood Decay Fungi
Easter red cedar (Juniperus virginiana) is a valuable source of heartwood extractives that provide decay resistance against termites and wood decay fungi. This study sought to determine the antifungal activity of heartwood extracts obtained using solvents with increasing polarity (hexane, chloroform, ethyl acetate, and methanol) against two wood decay fungi. The heartwood was extracted with methanol, and the methanol extract was sequentially extracted with hexane, chloroform, and ethyl acetate. The yield of the methanol extractives was 5.26 percent based on dry wood and the percentages of the hexane, chloroform, and ethyl acetate soluble fractions from the methanol extract were 46.4, 8.3, and 28.7 percent, respectively. Hexane and chloroform soluble fractions showed a high inhibitory effect on the growth of the wood decay fungi Trametes versicolor and Gloeophyllum trabeum. Gas chromatography–mass spectrometry analysis identified skeletons of sesquiterpenes and sesquiterpene alcohols in both extracts and the most abundant compounds identified, cedrol, cedrenes, and thujopsenes, were individually screened for antifungal activity. Among the three major sesquiterpenes, cedrol and thujopsene showed the highest inhibitory effects against G. trabeum and T. versicolor, respectively.
A series of joint treatments on southern pine, red oak, and yellow-poplar were evaluated. These included treatments applied in holes that were subsequently capped, treatments applied to bolt holes and/or bolts, treatments applied to felt pads located between wooden members, and treatments applied directly to the surfaces of the joints. Water-soluble diffusible systems applied in holes adjacent to joints generally performed more poorly than expected because of the lack of rainfall during the exposure period. The notable exception was a copper-borate paste applied directly to the joint area. Application of a solvent-borne copper naphthenate with or without a water repellent to felt pads was also very effective. Water repellent alone and fumigant treatments gave unsatisfactory performance over the long term. To simulate hazards encountered by piling, kiln-dried untreated southern pine pole stubs that received various supplemental treatments were placed in the field for 41 months. Upon groundline evaluation of these test specimens, it was noted that seven preservatives or combinations of preservatives looked very favorable. The following treatments yielded sound stubs with no evidence of decay or insect attack: (1) copper-borate paste applied to the surface at and below groundline; (2) copper-borate paste applied to the surface at and below groundline plus boron rods inserted into holes near groundline; (3) copper-borate paste applied to the surface at and below groundline plus fumigant inserted into holes near groundline; (4) pentachlorophenol grease applied to the surface at and below groundline; (5) fluoride paste applied to the surface at and below groundline; (6) fluoride paste applied to the surface at and below groundline plus boron rods inserted into holes near groundline; and (7) fluoride paste applied to the surface at and below groundline plus fumigant inserted into holes near groundline.
Logging firms, as suppliers of raw material, form an important part of Michigan's forest products industry. Given the increasing interest in wood-based bioenergy production, their role has become increasingly important. For this study, we used a mail survey of Michigan's logging firms to provide an outlook of the logging sector within the state. The aim was to understand the status of existing logging businesses and to explore their potential role in the woody biomass supply chain. Our findings reveal that the state's logging firms have been facing difficulty in retaining their business and in running operations profitably in recent years. Mill closures in the past decade have had significant negative impacts on half of the responding firms. Given this situation, the introduction of wood-to-energy facilities could provide new market opportunities for logging firms in the state. Loggers in general were found to be supportive of introducing such facilities in their wood basket. Availability of timber to meet the feedstock demands of new and existing facilities could, however, become a challenging issue in the future. Insufficient timber sales and high stumpage prices were identified as the major barriers to increased harvesting by the logging firms in our survey. On average, the responding firms reported that in the majority (83%) of their logging jobs, they leave logging residues on site, suggesting that there is little or no market for such materials at present. This could change, however, with market development and improvement in the logging and transportation facilities in the future.
Today, an information gap exists between log measurements performed in the forest and at the sawmill. By applying a code in the forest during harvesting and then reading it at the sawmill, this information gap would vanish. A log applicator, which applies two-dimensional log codes through the saw bar, and a corresponding detection system based on vision technology have been developed. Key features of this technology are the very low cost of each mark and the zero-time-loss characteristic of both marking and detection. A field test utilizing this equipment was performed on 210 logs in northern Sweden in December 2009. For logs harvested during real harvesting conditions and automatically detected at the log sorting station of a running sawmill, a detection rate of 40 percent was achieved. A comparison between parameters (length and diameter) measured in the forest and at the sawmill is presented, as are a number of suggested improvements to increase the detection rate substantially.
This study evaluated the applicability of substituting flakes in the core layer of oriented strand board (OSB) with chips from comminuted and unrefined particle boards and wood waste. Results from the analyses show that the applied modification of the core, even at a relatively high proportion of chips (amounting to 75%) makes it possible to manufacture OSB with good mechanical properties, meeting the requirements of the standard EN 300. In contrast, the use of melamine–urea–phenol–formaldehyde resin does not guarantee the requirements (in terms of moisture resistance) will be met.
Mountain pine beetle (Dendroctonus ponderosae)–infested lodgepole pine (Pinus contorta) bark was used to make particleboard panels (bark board) without synthetic resins. The effects of pressing temperature and particle size on the mechanical properties of the bark boards were examined. The study revealed that pressing temperature and particle size have great influence on mechanical, physical, and hygroscopic properties of self-bonded bark boards. Higher pressing temperatures resulted in improvements in all properties studied, including increases of modulus of elasticity and modulus of rupture by approximately 4 times and an increase of internal bond strength by nearly 10 times when comparing boards pressed at 170°C versus 230°C. Boards produced from fine bark particles showed better mechanical performance than boards produced from coarser bark particles except for internal bond strength, which was highest in boards containing bark particles of mixed sizes. Scanning electron microscopic images of fractured surfaces of bark boards derived from different particle sizes and pressed at different temperatures indicated that fine and mixed particles and higher pressing temperatures led to denser packing.
Establishing long-term relationships with Taiwanese lumber buyers generates profits and lowers costs. Marketing efforts, trust, and brand equity may be factors that strengthen relationships in this market. In this study, we assessed the relationships among these constructs using the structural equation model and data collected from a questionnaire sent to Taiwanese lumber importers. Path parameters are found to be statistically significant except for the link between brand equity and trust. Some factors must exist between these two constructs, and further exploration may be necessary in the future. The mediating effects of brand equity and trust are discovered between marketing efforts and customer loyalty. It suggests that lumber suppliers should focus marketing efforts on brand equity and customer trust in order to create customer loyalty.