The current status of southern yellow pine (SYP) lumber use in the Japanese housing and construction markets is reviewed and compared with other Asian markets. We look into the lack of SYP lumber penetration in the Japanese construction markets, approaching the topic from the perspective of regulations, product quality, awareness, and marketing. Finally, the analyses suggest how SYP producers can penetrate the Japanese market and develop increased demand for SYP products.Abstract
Composite sampling is standard practice for evaluation of preservative retention levels in preservative-treated wood. Current protocols provide an average retention value but no estimate of uncertainty. Here we describe a statistical method for calculating uncertainty estimates using the standard sampling regime with minimal additional chemical analysis. This tool can be used by wood treaters to generate lower prediction intervals that with a certain level of confidence give lower bounds on preservative retention estimates for a future analysis (e.g., by a customer) indicating whether the treated wood charge would result in a below-target retention value.Abstract
Primary wood products manufacturers generate significant amounts of woody biomass residues that can be used as feedstocks for distributed-scale thermochemical conversion systems that produce valuable bioenergy and bioproducts. However, private investment in these technologies is driven primarily by financial performance, which is often unknown for new technologies with limited industrial deployment. In this paper, we use shift-level production data collected during a 25-day field study to characterize the conversion rate and system productivity and costs for a commercially available pyrolysis system co-located at a sawmill, and then evaluate the net present value (NPV) of the operation in light of a cost structure that is realistic for the industry. Baseline costs on a feedstock throughput basis were estimated as $16.41 t−1 for feedstock preparation, $308.14 t−1 for conversion, and $65.99 t−1 for biochar bagging. The NPV estimated for the worst-case scenario of observed productivity and conversion rate was −$536,031 for a 10-year project period, while the best case scenario generated an NPV of $467,353. In general, NPV is highly sensitive to labor costs and biochar price, and less sensitive to fuel cost and interest rate. Results also show clear opportunities for technical and operational improvements that are expected to increase the financial viability of this system.Abstract
Matching the right feedstock quality to a biomass conversion technology effectively facilitates the energy conversion process and improves the economic feasibility of forest biomass for energy production. In this study, we conducted a controlled experiment on a horizontal grinder to evaluate the effect of three different grate size combinations on grinding productivity, fuel consumption, and particle size distribution for two different biomass types (mixed conifer slash and hardwood whole trees). Mixed conifer slash resulted in higher grinding productivity (39.0 to 45.1 bone dry US tons/h) and a lower fuel consumption rate (0.57 to 0.90 gal/h) than hardwood whole trees. Small grate size configurations (2-, 3-, and 3-in. holes) in the grinder had low grinding productivity and higher fuel consumption rates compared with large grate size configurations (3-, 4-, and 4-in. holes). High grinding productivity and low fuel consumption rates were accomplished by using a new anvil type that is manufactured with holes in the plate. The study also showed that production of small feedstock particles (length, <2 in.) from logging slash was operationally feasible by using small grates and a newly designed anvil. Additional research is needed to further control oversized materials and improve our knowledge about the effect of moisture content on grinding productivity, especially with a wide range of grate size combinations.Abstract
Overcrowded forests have allowed several catastrophic wildfires to burn in Colorado. Many of these fires have received national attention and inspired large public expenditures into community wildfire mitigation projects. Forestry projects in Colorado have shifted away from traditional logging and toward service-type projects, such as forest thinning and defensible space, and Colorado's forestry contractors are essential in realizing forest management objectives in the state. Many southeastern and northeastern states conduct regular surveys of forestry contractors to better understand their attributes and ability to adapt to changing conditions. This article presents results of a Colorado forestry contractor survey conducted in 2014. Objectives of this survey were to gain statistical information about the contractors, establish a baseline for future surveys, and determine the capacity of the workforce to address the state's forest health issues. The survey revealed a diminished workforce that has struggled to find identity following policy changes and economic events of the 21st century. This survey also revealed that with the current contractor capacity, Colorado will be unable to face the many threats to forest health and prevent catastrophic wildfire.Abstract
Gas chromatography–mass spectrometry (GC-MS), along with other chromatography and spectroscopy techniques, has been used to provide convenient, rapid, and accurate information for identifying wood species. However, different sampling methods are capable of affecting the final results. Therefore, two different sampling methods, namely, direct injection of liquid wood extractives (DIWE) and head space of wood powder (HSWP), of GC-MS were compared in this work when typical Hongmu Pterocarpus santalinus was selected as the material. It was found that the number of chemical compounds produced by HSWP is less than the number produced by DIWE, and the boiling points of the HSWP compounds were also lower than the counterparts of DIWE because their retaining time in GC-MS spectrum is longer. It should be mentioned that the procedure of sample preparation for HSWP is simpler and more convenient than for DIWE, which gives HSWP an advantage over DIWE when many wood samples need to be identified by GC-MS. In addition, fingerprints of GC-MS spectra in both methods have been established as a histogram according to the main peaks in the spectra.Abstract
Chainsaw kickback is a serious safety concern for both experienced and novice operators. A key to developing improved kickback control systems is a better understanding of saw motion during kickback and the development of improved methods for distinguishing kickback from normal saw operation. In this study, accelerometers and gyroscopes were mounted to a battery-powered electric chainsaw and to a midsize, gasoline-powered chainsaw, and data were collected during normal cutting and kickbacks. These sensors measured accelerations along the guide bar and perpendicular to the bar as well as rotational velocities toward the operator's torso. Results from the battery-powered saw showed that accelerations during normal cutting and kickbacks had peak magnitudes of from ~2 to ~6 g and from ~6 to ~8 g, respectively, and that rotational velocities typically reached over 600°/s during a kickback. Analysis of these results showed that the gyroscope alone, using a threshold value of 300°/s, was effective in distinguishing normal cutting from kickback. Results from the gasoline-powered saw showed the same general trends as those with the battery-powered saw; however, the rotational velocities during a kickback were greater, typically exceeding 1,000°/s. Through the use of machine learning techniques, a more effective method than a simple threshold for distinguishing kickback from normal saw operation was developed. Using this method, kickback was determined very reliably and often when the deviations from the rotational velocities corresponding to normal cutting were small. Implementation of these findings could lead to improved kickback control systems on chainsaws.Abstract
A long-term strategy within the forest products industries is to increase the products' refinement and thus their value. This strategy applies to both primary and secondary processed wood products. Further down the value stream, different kinds of knowledge are needed in order to add value and efficiency in the supplier process. In this study, the focus was on as-built three-dimensional (3-D) sensing as a means to increase the level of product prefabrication when supplying engineer-to-order joinery products to the construction industry. A 7-m ranging three-axis portable wire-based coordinate-measuring machine (PWCMM) was evaluated in terms of performing as-built site-dimensional verification in 3-D. This is a needed means for moving the fitting of joinery products into the digital domain at the design stage, thus increasing the level of prefabrication and automation possible when supplying engineer-to-order joinery products. The PWCMM has been used to replicate different construction sites to gain as-built spatial information as input into the suppliers' design, manufacturing, and on-site assembly processes. The evaluation shows that the accuracy in each coordinate position can be within a millimeter range. However, questions still remain about the capability to meet the demands on accuracy and usability for on-site dimensional verification when supplying joinery products. Issues with error leverage and low measurement resolution limit the practical possibilities in terms of level of accuracy and detail of the reproduction of the as-built environment.Abstract
Natural materials in indoor settings influence the human organism positively. Wood is a natural material and shows similar positive effects on the individual's well-being. Because of similar looks and functional properties, wood can be compared with laminate. However, when investigating psychological differences, wood is usually compared with carpets, glass, leather, stone, or plastic, but not compared with a visually similar material such as laminate. The aim of this study was to analyze and compare the different psychological perception of wood and laminate products in an indoor setting. This study further investigated what specific psychological aspects can differentiate wood from laminate products, and if wood is preferred over laminate and is more likely to be purchased. Different pictures that depict wood and laminate products in an indoor setting were used to evaluate the psychological perception. This evaluation included measuring 11 quality criteria, the perception of the environmental atmosphere, and the purchase decision. The experimental design was a 2 × 2 × 2 design with repeated measures for material and sequence. The sample consisted of 93 experts as well as nonexperts for wood. The result shows that wood products are rated higher than laminate products regarding several psychological aspects, such as health, physical and mental stimulation, and performance enhancement. In addition, wood products were rated significantly more warming and cozy, and the participants would recommend, purchase, and accept more deficiencies for purchasing wood products than for laminate products. Overall, the material wood was preferred over the material laminate.Abstract
Most thermal modification studies have attempted to improve the durability of sapwood; however, it may be more fruitful to improve the durability of heartwood that already has some inherent durability. The effects of pretreatments with boron or glycerol coupled with thermal modification on resistance to mold growth and fungal degradation were examined for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) heartwood, which is classified as moderately durable. Pretreatment with boron had marked effects on resistance to both mold and decay fungi, but the results were consistent with the well-known effects of this fungicide. Pretreatment with glycerol appeared to reduce mold resistance and had no effect on degradation by decay fungi. Thermal modification enhanced mold resistance with increasing temperature but had only a slight effect on decay resistance. These results suggest that thermal modification does not enhance performance to levels that meet North American durability requirements for aboveground, exterior exposures.Abstract
Small-diameter logs from plantation trees are prone to warp and to produce checks due to the presence of juvenile wood, growth stresses, and asymmetric shrinkage during the drying process. In the present study, we analyzed the possibility of producing sawn timber beams by using the inside-out (ISO) process. The material for the sawn timber beams was obtained from small-diameter logs of three tropical species planted in Costa Rica (Gmelina arborea, Tectona grandis, and Cordia alliodora). Changes in warp (crook and twist), checks (quantity, length, and depth), flexural and shear resistance, and glue line delamination were evaluated. We found that it was possible to produce beams from small-diameter logs of fast-growing plantations. This was achieved by turning the pith inside out and then gluing the green pieces. The ISO beams showed less warp and checking compared with solid wood. The modulus of rupture in the flexural test was not affected; however, the modulus of elasticity decreased. In the case of the glue line's shear resistance, the performance of G. arborea and C. alliodora were similar to that of solid wood, but T. grandis presented adherence problems, which caused low values of shear resistance.Abstract
This study evaluated the effects of treatment type of reed (Arundo donax) particles bonded with urea-formaldehyde resin in panels, press closing time, and amount of almond shell powder used as an extender in the glue line had on the modulus of rupture (MOR) of sandwich panels in dry and wet conditions. The differences between the bending strength parallel and perpendicular to the face/back veneer grain in dry (MOR||dry and MOR⊥dry) and wet (MOR||wet and MOR⊥wet) conditions were determined using the t test. According to the results, the selected variables significantly affected the bending strength. The highest dry and wet MORs were obtained by using hot-water–leached particles in the core layer, increasing the press closing time, and increasing the extender content in the glue line. According to the t test, there was a statistically significant difference between the t values of MOR||dry and MOR⊥dry and also between MOR||wet and MOR⊥wet. The maximum MOR||dry and MOR||wet (15.33 and 13.13 N/mm2, respectively) were observed to be higher than those of MOR⊥dry and MOR⊥wet (13.37 and 12.41 N/mm2, respectively).Abstract