Wood and Fiber Science (E-Journal)
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Use of Biocides and Soy Oil in Preservative Treatment of Structural Flakeboard
Get PDFMany uses of structural wood composite panels require preservative treatment to increase decay resistance. The most cost-effective way to treat structural flakeboard is done during manufacturing, but it is difficult to accomplish because of incompatibility between adhesive resins and preservatives. The objective of this study was to evaluate physical properties and decay resistance of flakeboard made with phenolic wood adhesive resins blended with biocides dissolved in soybean oil. The blended phenolic adhesive resins contained equal parts of iodo-propynyl butyl carbamate, propiconazole, and tebuconazole. Hybrid poplar flakeboards were made at the combined biocide retention levels of 0, 0.51, 0.81, and 1.63 kg/m3. Results indicated that the strength and dimensional stability properties of flakeboard were not affected by the in-process preservative treatment. The biocides were stable and maintained their efficacy against decay after pressing boards at 200°C for 7 min. Boards treated with 1.63 kg/m3 biocides sustained 2.5% to 5.0% weight loss after exposing to the brown-rot fungus (Postia placenta) for 12 wk compared with over 27% weight loss of nontreated boards
A Product Semantic Study of the Influence of Vision on Wood Evaluation
Get PDFUsing product semantics, this study investigated how visual attributes of wood are perceived and interpreted semantically. The wood species alder, ash, aspen, beech, birch, elm, larch, lime, maple, oak, pine, and spruce were included. The subjects rated the samples based on the descriptive words natural, exclusive, ecofriendly, rough, inexpensive, modern, reliable, warm, cozy, solid, and light. The most significant differences in ratings were between softwoods and hardwoods. Principal component analysis yielded three dimensions based on visual perceptions: exclusive-modern, ecofriendly-natural, and light. Maple and ash and other hardwoods were seen as more exclusive and modern than spruce and pine. Pine, conversely, was perceived as the most ecofriendly-natural wood type. Beech and alder did not score high (or low) on any of the three dimensions, meaning that these gave a neutral impression. The potential use of these results in product design and interior design is discussed
Moisture Content Prediction Below and Above Fiber Saturation Point by Partial Least Squares Regression Analysis on Near Infrared Absorption Spectra of Korean Pine
Get PDFThis study was performed to predict the surface moisture content of Korean pine (Pinus koraiensis) with low moisture content (approximately 0%) and high moisture content above the FSP using near IR spectroscopy. Near IR absorbance spectra of circular specimens were acquired at various moisture contents at 25°C. To enhance the precision of the regression model, mathematical preprocessing was performed by determining the three-point moving average and Norris second derivatives. After preprocessing, partial least squares regression was carried out to establish the surface moisture content prediction model. We divided the specimens into two groups based on their moisture contents. For the first group, which possessed moisture contents less than 30%, the R2 values and root mean squared error of prediction (RMSEP) of the model were 0.96 and 1.48, respectively. For the second group, which possessed moisture contents greater than 30%, the R2 values and RMSEP of the model were 0.94 and 4.88, respectively. For all moisture contents, the R2 and RMSEP were 0.96 and 5.15, respectively. As the range of moisture contents included in the prediction model was expanded, the error of the model increased. In addition, the peak positions of the water absorption band (1440 and 1930 nm) shifted to longer wavelengths at higher moisture contents
Determining Surface Emission Coefficient of Wood Using Theoretical Methods and Near-Infrared Spectroscopy
No full textEmission of surface water on wood should be controlled because moisture movement on the wood surface initiates changes in its morphological, physical, chemical, and biological properties. In this study, surface moisture content (SMC) of yellow poplar (Liriodendron tulipifera L.) wood was measured by a near-infrared spectroscopy (NIRS) technique, nondestructively and continuously, during unsteady-state desorption conditions. With these SMC data, surface emission coefficients (SECs) were determined continuously while the wood was being dried. These experimentally determined coefficients were compared with values that were converted from the theoretically determined mass transfer coefficients. The conversion method, which was developed to facilitate a comparison among the mass transfer coefficients, indicated that the boundary layer theory was useful in evaluating the degree of external moisture resistance while the wood dried. Also, the NIRS technique can be used for determining SEC at each specific point of wood, experimentally, in real time
A Life Cycle Analysis of Forest Carbon Balance and Carbon Emissions of Timber Harvesting in West Virginia
No full textA life cycle inventory framework of "cradle to gate" combined with Monte Carlo stochastic simulation was used to analyze the forest carbon balance and emissions from mechanized and manual harvesting operations from 2000 to 2009 in West Virginia. Mechanized and manual harvesting operations were compared on the slope of the sites ranging from 10 to 35% where average diameter at breast height of harvested trees was 40.64 cm. The results showed that the annual carbon balance of the forests per hectare was not significantly affected by carbon loss from the removal of sawlog volume (or timber), fire, and limited dead trees, until tree mortality and/or harvesting intensity reached a high level. Additionally, it was found that average carbon emission from fossil fuel consumption was 5.06 ± 0.90 metric tons per thousand cubic meters (Mg/TCM) of timber produced for a manual harvesting system and 6.84 ± 1.22 Mg/TCM for a mechanized harvesting system. Approximately 1.71 and 2.31% of the stored carbon in processed lumber would be displaced by harvesting emissions, respectively, for manual and mechanized systems. The forest carbon displacement rate during timber harvesting was affected largely by hauling process, while felling, processing, skidding, and loading processes had smaller impacts. Among the harvest processes studied, uncertainty of carbon emissions from fuel consumption and forest carbon displacement rate could be attributed to hauling distance, payload size, forest type, and machine productivity
Intra- and Interclonal Variation in Anatomical Properties of Hevea Brasiliensis Muell. Arg.
No full textThe wood anatomical properties of two new rubberwood clones (RRIM 2020 [I] and RRIM 2025 [II]) at four planting densities (PDs) (500 [I], 1000 [II], 1500 [III], and 2000 [IV] trees/ha) were assessed. Fiber morphology, vessel features, and ray cell anatomy were measured. At PD I and PD II, fiber features were the highest quality. For vessel features, the highest quality was at PD I and PD IV. The moderate densities did not show substantial variation. Ray density from clone I demonstrated a direct relationship with PD because the highest value was at PD IV. Ray height showed a descending trend with increasing PD with significant differences in PD I and PD II vs PD III and PD IV in clone I. PD I showed the highest values with no significant difference compared with the others. PD in both clones did not significantly influence ray area. Some anatomical features of fiber, vessel, and ray were successfully quantified using a regression approach. The results predicted PD I as optimum for high wood quality production. Among the treatments, PD I of clone II resulted in the best quality anatomical properties
Image Processing Method as a Supporting Tool for Wood Species Identification
No full textExamination of wood sections using microscopy is often not very satisfactory for species identification, and this may be the case for samples taken from objects needing restoration. This could be caused by various parameters, namely small size of the section, condition of the section related to its age or degradation, finishes penetrating the wood material as well as sections not covering a representative area to have an objective and accurate wood identification. An image analysis method based on ImageJ, an image processing program intended for medical microscopy, was used in this work. The method is useful for wood because it offers an objective quantitative way to separate and measure anatomical structures of the section allowing statistical analysis of the data to be carried out. This is a case study related to identifying samples from three furniture pieces needing restoration. Microslides were prepared from small samples of each furniture unit. These were observed with transmitted light microscopy. Each sample was identified by examining the microscopic images, which were interpreted for their common but also specific features and characteristics by means of ImageJ analysis and compared with reference microscopic images of known species and their characteristics provided by the literature. The species identified in this study were found to have diffuse pores. Further work should address more wood species, including softwoods, to check the usefulness of the image processing method on various situations and to understand its limitations
Characteristics of Silvergrass and Feasibility of Silica as a Waterproof Agent in Silvergrass Particleboard
No full textSilvergrass is a natural biological material and, in this study, the feasibility of it being used as raw material for particleboard was investigated. The results of pH value, buffering capacity, and surface wettability determinations indicated silvergrass could be glued with urea-formaldehyde resin. The main elements of silvergrass stalk, which included carbon, oxygen, and silicon, were determined by energy dispersive analysis of X-rays. Silicon occurs in silvergrass stalk as compound silica, and the silica content of stalk was 3.49%, which indicated silica may play the role of a waterproof agent in particleboard. Feasibility of silica being used as a waterproof agent of silvergrass particleboard was analyzed, and results showed silica actually functioned as a waterproof agent, therefore wax was not needed in silvergrass particleboard manufacture
Antimicrobial Properties of the Hybrid Copper Nanoparticles-Carboxymethyl Cellulose
No full textIn this study, a simple method to produce a cellulose-based material with antimicrobial properties was developed by introducing copper nanoparticles on carboxymethyl cellulose (CMC) using sodium borohydride as a copper reducing agent. The hybrid material was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). SEM and EDX analysis confirmed the formation of copper nanoparticles within the CMC matrix. TEM indicated a 10- to 20-nm diameter of copper nanoparticles. Antimicrobial properties of the hybrid material were effectively evaluated against the nonpathogenic surrogate of foodborne pathogen Escherichia coli