Copper sulfate can be utilized to stimulate fungal pigment production for commercial spalting applications. This research explored two larger-scale uses for fungus stimulation by copper: “drawing” exclusion areas on sugar maple by surface application of copper sulfate and the use of copper sulfate in dual-fungi inoculation systems to increase the number of colors and types of spalting produced. Sugar maple boards treated with 2 mL of 0.13 percent copper sulfate in an S pattern and inoculated with Xylaria polymorpha showed a distinct area of clear wood, followed by thick dark zone lines and then by a general black pigmentation expanding outward from the S. Sugar maple blocks treated with 0.06 kg/m3 copper sulfate and inoculated with X. polymorpha/Arthrographis cuboidea had fewer black zone lines than the control blocks but more pink zone lines and internal pink stain.
Mindi wood (Melia azedarach) and sugi wood (Cryptomeria japonica) were smoked for 15 days using mangium wood (Acacia mangium), and for comparison purposes, wood preserved with 5 percent borax, polystyrened wood, and untreated control wood were prepared. All of the wood specimens were tested for resistance to (1) subterranean termites (Coptotermes curvignathus Holmgren) in the laboratory, (2) dry wood termites (Cryptotermes cynocephalus Light) in the laboratory, and (3) subterranean termites in the field or via in-ground tests. The results showed that (1) mindi wood was more resistant than sugi wood to subterranean termite and dry wood termite attacks; (2) with regard to the Indonesian termite test standard, smoke treatment increased wood resistance to termite attacks, matching the highest resistance class of subterranean termites and dry wood termites; and (3) mindi wood offered equal resistance compared with polystyrened wood and wood preserved with borax, but in terms of the in-ground test, the smoke treatment did not affect wood resistance to termite attack, presumably because of leaching that occurred during the exposure test.
This study tests the hypothesis that the effectiveness of surface profiling at reducing the checking of deck boards exposed to weathering varies with wood species and profile type. Southern pine (Pinus sp.) and Pacific silver fir (Abies amabilis) deck boards were machined to produce three different types of surface profiles: flat (control), ribbed (V-shaped grooves), and rippled (U-shaped grooves). Boards were exposed to accelerated weathering for 5 days, and the number and sizes of checks that developed in boards were quantified. Surface profiling reduced the total number and total width of checks in both Pacific silver fir and southern pine deck board specimens, but it had a greater effect at reducing checking in Pacific silver fir than in southern pine. The ribbed profile, in particular, was much more effective at reducing checking of Pacific silver fir than it was at reducing the checking of southern pine. Therefore, we conclude that the effectiveness of surface profiling at reducing checking of deck boards depends on wood species and the type of profile machined into wood surfaces. Checks developed in the grooves between the ribs of profiled boards and appeared to be constrained from becoming wider to a greater extent than becoming longer. Therefore, we conclude that the beneficial effect of profiling on the appearance of boards arises because checks are much narrower than those on flat boards and are located in the grooves, where they are difficult to see.
Plywood is widely used as a substrate in engineered wood flooring (EWF) construction. While the Canadian EWF industry largely relies on Baltic birch plywood (BBP), the development of an alternative substrate is clearly desirable. The objective of this study was to evaluate the long-term performance of EWF made with an oriented strand board (OSB) substrate designed to deliver a higher than normal internal bond. Three-layer OSB panels were made from a mixture of 90 percent aspen (Populus tremuloides) and 10 percent paper birch (Betula papyrifera). Three adhesive configurations were used in the manufacture of specialty OSB panels: 100 percent liquid phenol formaldehyde (PF) resin, a mixture of 60 percent liquid PF resin and 40 percent powder PF resin, and 100 percent polydiphenylmethane diisocyanate (pMDI) resin. The performance of these three specialty OSB products was studied. Five types of substrate were used in the manufacture of EWF: BBP, sheathing OSB, and the three specialty OSBs. A polyurethane adhesive was selected to bond the surface layers to the substrates. The result of this experimental study indicated no significant difference between the long-term performance of the OSB substrate made with pMDI resin and that of the BBP substrate.
The tensile, flexural, and impact strength distribution and the cost-effectiveness of kenaf bast fiber bundle (KBFB)–reinforced unsaturated polyester composites were studied. Probability models including normal, two-parameter Weibull, gamma, lognormal, exponential, Burr, Pareto, and inverse Gaussian models were fitted against measured composite strengths. Taking the 5th percentile values as the composite's strength design values, the two-parameter Weibull model provided the most conservative composite strength design values. A cost-effectiveness analysis showed these composites were more cost-effective than glass fiber–reinforced sheet molding compounds (SMCs) for carrying tensile and flexural loads when their fiber loadings reached 51.2 and 56.3 percent (wt/wt), respectively. The KBFB-reinforced unsaturated polyester composites were less cost-effective than glass fiber–reinforced SMCs for carrying impact loads. This work suggests that natural fiber–reinforced composites have the potential to be viable replacement materials in applications where impact resistance is not critical.
Bamboo charcoal, silica, and phenol-formaldehyde resin were mixed powders that were heated at temperatures from 1,500°C to 1,800°C in an argon atmosphere to produce a silicon carbide (SiC) ceramic. Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDXA) were used to monitor heat flow and physical, chemical, and structural changes during the formation of the ceramic. The DSC results indicated that during firing, endothermic reactions occurred below 800°C, after which exothermic reactions dominated. FTIR study suggested conversion of Si-O bonds to Si-C bonds at temperatures above 1,500°C. SEM and EDXA showed that the microstructure of the bamboo charcoal was observable in the ceramic structure and that the surface of the ceramic material contained a high proportion of Si. X-ray diffractometry analysis indicated that the ceramics obtained by firing above 1,650°C mainly consisted of SiC with trace amounts of elemental carbon and silicon.
Carbon-encapsulated metal nanoparticles were synthesized by thermal treatment of wood char, with or without transition metal ions pre-impregnated, at 900°C to 1,100°C. Nanoparticles with concentric multilayer shells were observed. The nanoparticles were analyzed by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The EDX spectrum showed that carbon was the dominant element in the shells. TEM and XRD analysis indicated that the generated carbon shells had structures similar to that of graphite with an average interplanar distance of 0.34 nm. The effects of temperature and pre-impregnation of metal ions on the yield of carbon-encapsulated metal nanoparticles were studied.
Formaldehyde-free wood adhesives based on combinations of soy flour and polyamidoamine-epichlorohydrin (PAE) resins are being used commercially. This combination has been shown to provide enhanced strength and water resistance compared with traditional soy-based adhesives. This study was undertaken to better understand the molecular interactions between a PAE resin and the various components of soy flour. PAE resins are cationic, water-soluble, thermosetting resins that contain high levels of azetidinium functionality. The main components of soy flour are protein (~50%), polysaccharides (15% to 25%), and soluble sugars (10% to 15%). Solid-state nuclear magnetic resonance spectroscopy (SSNMR) was used to study the molecular interactions occurring between soy flour components and a PAE resin. In these initial studies the efficiency of spin diffusion was observed and related to morphological differences between formulations comprising different ratios of PAE resin and soy flour. The thermal transitions of these adhesive formulations were explored using differential scanning calorimetry (DSC).
The North American wood fiber–plastic composite (WPC) industry has experienced significant growth since its inception in the early 1990s. Consumer demand for durable, low-maintenance, chemical-free outdoor building materials led to 23 WPC producers with 95 total brands of decking, railing, and fencing and a multitude of other WPC products in 2008. These products are differentiated on a myriad of product and service attributes and are defined by branded offerings in the North American marketplace. This study investigates the number of brands, brand name development, and brand strategy benefits in the North American WPC industry in 2008. Data were collected via secondary sources and semistructured interviews with WPC brand managers (response rate = 14 of 23 [61%], representing an estimated 88% of WPC industry sales). Findings indicate that WPC manufacturers utilize a wide array of internal and external resources when developing brand names and perceive branding as an important marketing tool. Product identification and differentiation were the highest rated benefits of a firm's brand strategy, and the proliferation of brand names is largely a result of the proliferation of manufacturers and their desire to differentiate product offerings. This research will help business-to-business marketers of wood-based building materials better understand the strategic considerations of branding differentiated products.
Efficient and effective supply chains are the backbone of any industry, including the forest products industry. As the US secondary hardwood industry has undergone a profound transformation and large parts of the industry have moved offshore, the supply chain is adapting to these new realities. Remaining and new customers of US hardwood lumber distributors tend to be smaller and likely have a wide variety of unique needs and expectations. A survey conducted in the fall of 2008 of distributors of hardwood lumber assessed the sourcing needs and perceptions of the industry and describes the status of the industry as of 2007. The findings suggest that the US hardwood lumber industry is adapting to the new realities brought forth by the globalization of markets and slowing housing markets. Almost half of the respondents indicated that their average customer in 2007 was smaller than the average customer in 2003, and 75 percent of respondents indicated that the average order was smaller in 2007 versus 2003. To accommodate their customers, distributors added a plethora of new services, with provision of certified products being the fastest growing. Overall, the study depicts an ongoing transformation of the US hardwood lumber supply chain, where distributors are well positioned to meet the exacting specifications of numerous small and customized manufacturers.
Arkansas is endowed with vast forest resources, but the number of wood-utilizing industries is declining. A cartographic representation of the location of existing industries is needed to understand their spatial distribution trends and identify possible factors relating to their site preferences. We obtained coordinates of these industries from ZipList5 Geocode and overlaid them onto spatial data, including Land-Use/Land-Cover (LULC) raster data model, county- and city-limits vector data model, county-level population, and average house listing price in ArcMap. We used ArcGIS spatial analyst tools to reclassify and vectorize the LULC model based on timber supply potential and then categorized the subsectors of wood-utilizing industries based on their numeric and/or financial dominance. Spearman's nonparametric correlation showed that county-level counts of industries were not significantly related to population (r = 0.193, P = 0.097) and city limits (r = 0.062, P = 0.600) but were significantly related to timber supply area LULC type (r = 0.284, P = 0.014) and average house listing price (r = 0.419, P < 0.0001). This study provides spatially based knowledge about site-selection preferences for wood-utilizing industries, which is critical for potential investors, resource administrators, and wood-industry businesses in Arkansas.