The properties of strand-based wood composites are known to be strongly influenced by strand orientation and horizontal density variation. While the influence of these geometrical factors on performance has been extensively investigated for more than 20 years, little research has been reported on how the strands move during the forming process to become oriented and located. Better knowledge of strand movement will allow for understanding of and improvement in mat formation through rational modification of equipment settings and ultimately design concepts.

An industrial forming line was used to quantify the effect of strand length on strand movement from the bunker through the picker rolls, dissolving rolls, and orienting heads. Initial locations of dyed strands in the forming bin bunker were predetermined. After processing through the forming head, the location and orientation of individual strands were optically measured before and after the orienting deck.

Nine-inch strands were found to have a more variable flow rate through the picker rolls relative to 4-inch strands. Substantial strand mixing and horizontal travel across the width of the forming head occurs prior to the orientation deck. This indicates that modifications in the strand chute will influence the cross-direction movement uniformity and final product density variation more than orienting deck modifications. As expected, longer strands were shown to project significantly farther along the orienting deck as well as to provide better alignment. A particle screen analysis showed that the doffing and dissolving rolls generated 70 percent of the unders (smallest screen fraction) in the forming process.

We attempted to use wood shavings in their raw curled flake form as a base material in a mat to be used primarily as a heat-insulating/acoustic material in houses. The molding succeeded in producing a low-density (0.03 to 0.08 g/cm³) wooden molding mat with bicomponent fibers as the binding component. After evaluating self-support and form retention, the inclusion of kenaf bast fiber was found to improve formability. Self-support and form retention were found with a combination including 5 percent bicomponent fiber. For examining the molding process, a relatively simple method of using a dust collector with an air blower that is used in carpentry allowed spreading of various fibrous materials and homogeneous mixing of the ingredients. Thermoforming could be achieved over a short time by using a heat-through dryer.

Mechanically retted short kenaf bast fiber bundle (KBFB)–reinforced unsaturated polyester (UPE) composites were fabricated. The effects of fiber loadings and aspect ratios on composite tensile properties were evaluated experimentally and theoretically. Tensile properties of KBFBs and the neat cured UPE were determined, and kenaf-UPE shear bonding strengths were measured. These measured properties were used to predict the tensile properties of the short KBFB-reinforced UPE composites using classical models in micromechanics. Theoretical tensile moduli predicted by Halpin–Tsai, Mori–Tanaka, and Self-Consistent models were in good agreement with experimental results. Theoretical tensile strengths predicted by the Kelly–Tyson model correlated well with experimental results at high fiber aspect ratios. Both composite tensile moduli and strengths increased consistently with increasing fiber loadings up to 75 percent (vol/vol).

Numerical simulation of structural member behavior requires knowledge of mechanical properties. This study proposes a methodology to obtain reliable mechanical properties of the oriented strandboard (OSB) web of I-joists, including variability. OSB panel samples were scanned by X-ray densitometry to measure in-plane density variation. Specimens were cut from predefined homogeneous density areas in three different orientations (parallel, perpendicular, and diagonal to the strong axis) to measure three basic elastic properties required for an elastic model of the OSB web of I-joists: modulus of elasticity (MOE) parallel and perpendicular to the panel's strong axis and shear modulus (G). Given the required small specimen size, shear modulus was determined using a combination of in-plane tensile MOEs, including MOE at 45°. Results showed a strong relationship between OSB density and small-scale mechanical properties: coefficients of determination (R²) varied between 0.57 and 0.79. This provided information on I-joist OSB web mechanical properties as a function of density for input into a numerical model. Properties showed considerable variability in the 600 to 900 kg/m³ density range, with a 207 percent increase in tensile modulus of elasticity in the parallel direction, 187 percent in the perpendicular direction, and 172 percent at 45°. The mechanics-based OSB shear modulus equation used proved to be reliable.

Three fast-growing trees, namely Acacia saligna, Conocarpus erectus, and Melia azedarach, as well as date palm (Phoenix dactylifera) midribs, were evaluated for their suitability for particleboard production. Panels were pressed at two target density levels of 750 and 650 kg/m³ and a thickness of 13 mm using 10 percent urea-formaldehyde resin. Modulus of rupture (MOR) mean values for the manufactured boards ranged from 13.34 to 6.7 MPa for date palm boards pressed at high density (HD) and C. erectus boards pressed at low density (LD), respectively. Modulus of elasticity (MOE) mean values ranged from 2,674 to 1,149 MPa for M. azedarach boards at HD and A. saligna boards at LD, respectively. According to the American National Standards Institute, all boards pressed at HD passed the minimum requirements for both MOR and MOE, except for A. saligna boards. On the other hand, all boards pressed at LD did not pass the standard, except for M. azedarach boards. The internal bond mean values of all boards were higher than the standard requirements, but the boards did not satisfy the linear expansion requirements for general uses. Concerning thickness swelling, date palm boards compressed at LD were the only boards that passed the English National Standard requirements for both 2-hour and 24-hour immersions. In general, all the species under investigation can be used in the particleboard industry if they are pressed at a density level of 750 kg/m³, while their dimensional stability properties might be improved by additional treatments, such as coating surfaces with melamine-impregnated papers or laminates in order to achieve a more stable product.

The disposal of forest-thinning residue is one of the major problems for sustainable forest management. The purpose of this study was to investigate the technical possibility of utilizing aspen logging slash wood with a diameter ranging from 50 to 76 mm for flakeboard production. Influences of weight ratio between slash wood and commercial flakes on the selected mechanical and physical properties of panels were examined. The need of an extra debarking process for panel fabrication was also evaluated. The results indicated the modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding, linear expansion (LE), thickness swelling (TS), and water adsorption of flakeboard made from aspen slash wood flakes were all comparable to those properties of panels made from aspen commercial flakes. The flake weight ratio between slash wood and commercial flakes had little impact on panel MOE, MOR, and LE. The statistical analysis (analysis of variance, P < 0.05) showed that the TS of panels made from 100 percent slash wood (22.8%) was significantly lower than the TS of panels made from a mixture of slash wood and commercial flakes or from 100 percent commercial flakes. The results indicate abundant slash wood, which is normally characterized by inferior mechanical and physical properties, could be a valuable resource for commercially available structural panel products.

Forestry residue-source oil-tea cake (consisting of plant protein, tannin, carbohydrate compounds, and tea saponin) is a major by-product from the pressing process of Camellia (Camellia oleifera Abel) seeds. In this study, we evaluated oil-tea cake as a potential extender to replace the current industry extender, wheat flour, for applications with phenol-formaldehyde (PF) plywood adhesives. We evaluated mixing properties, curing characteristics, and adhesion performance of the adhesive containing oil-tea cake as compared with those of the standard wheat flour–based adhesive. The oil-tea cake–based adhesive showed excellent mixing properties and working life, and its viscosity met the recommended value for the sprayline coater. The adhesive containing oil-tea cake was comparable in wet shear strength and wood failure values of plywood to the wheat flour–based adhesive. Thermal analysis showed that adhesives containing oil-tea cake had significant curing reactions because of the relatively large curing enthalpy (DH) value of oil-tea cake. These results indicate that oil-tea cake is suitable as a low-cost and effective plywood adhesive extender. Therefore, using oil-tea cake is economically beneficial because it not only makes use of what would otherwise be forestry residue, but it is cheaper to use as a plywood adhesive than wheat flour.

This article presents the characteristics of delamination wear on the clearance face of newly coated K10 cutting tools when milling particleboard. The K10 cutting tools were multilayer coated with titanium aluminum nitride (TiAlN)/titanium silicon nitride (TiSiN), TiAlN/titanium boron nitride (TiBN), and TiAlN/chromium aluminum nitride (CrAlN). Particleboard with a density of 0.61 g/cm³ was cut using the multilayer-coated tools and a monolayer-coated (TiAlN) tool. Cutting tests were performed at a high cutting speed of 41.8 m/s and a feed rate of 0.2 mm/rev to investigate the delamination wear on the clearance face of these coated tools. Experimental results showed that the newly multilayer-coated tools experienced a smaller amount of delamination wear than the monolayer-coated tool when milling the particleboard. The best multilayer coating was TiAlN/CrAlN; that tool only suffered a slight chipping on the cutting edge at a cutting length of 1 km. The high hardness, low coefficient of friction, high resistance to oxidation, and high resistance to delamination wear of the multilayer-coated TiAlN/CrAlN tool indicate a very promising applicability of this coating for high-speed cutting of abrasive wood-based materials.

Oriented strandboard (OSB) is a wood-based composite product with the largest market share for residential and commercial construction. Reliable in-line nondestructive evaluation devices are needed to rapidly determine OSB panel moisture content (MC) and specific gravity (SG) after hot pressing. In this report a radio frequency (RF) scanning technique was used to evaluate the MC and SG of OSB. RF scanning apparatuses were built to test OSB specimens at various MC and SG levels. Statistical models of the results were generated with the multiple linear regression method for estimating OSB MC and SG. The results indicated that the MC and SG of OSB can be estimated using RF responses in using voltage attenuation and signal phase shift.

Southern pine is the most common species used for utility poles in the United States. However, information regarding air emissions from pole drying is very limited. With respect to drying, poles have longer lengths, resulting in limited end-grain exposure, higher final moisture content, and lower ratios of surface area to volume, and typically southern pine poles have higher amounts of heartwood compared with southern pine lumber because of pole age. For this research, several green southern pine utility pole bolts were obtained and cut into matched kiln charges that contained sapwood only, mostly sapwood, mostly heartwood, and knotty material. Eight charges were dried at 230°F dry bulb with at least a 50°F wet bulb depression until the poles reached a moisture content of 30 percent at a depth 3 inches from the surface. Volatile organic emissions from the kiln charges were measured using federal guidelines. The mean emission values from the all sapwood, mostly sapwood, mostly heartwood, and knotty wood kiln charges were 3.59, 3.52, 2.64, and 3.65 pounds of volatile organic emissions per thousand board feet, respectively. The emissions of the sapwood, mostly sapwood, and knotty charges were similar to clear lumber emission values. The emissions from the knotty charges were less than emissions from knotty lumber. The results suggest that heartwood-rich utility poles release much less organic emissions than heartwood lumber, perhaps because of the band of sapwood that always surrounds the heartwood in poles as opposed to lumber where the heartwood is often exposed at the surface.

Steam-pressed scrim lumber (SPSL) involves crushing small diameter trees into mats that are coated with adhesive and pressed into boards. Water from the crushing process contains a high biological oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS). This water must be remediated before it can be discharged into public water systems. A 6-month study was conducted to evaluate the effectiveness of co-composting of the process water with wood waste and chicken manure as a method of remediation. Wood waste from the SPSL pilot facility in Shuqualak, Mississippi, was ground into small particles. This material was composted using four treatments: with or without added manure plus deionized (DI) water or process water to adjust moisture content. The compost end products for all treatments were evaluated for relative toxicity, weight loss, maturity, and suitability as a container substrate to grow plants. Additional testing determined the toxicity of compost leachate and evaluated the effects on germination rates of sensitive plant species. Co-composting successfully reduced the bulk and toxicity for all treatments. Treatments containing manure and process water showed over 90 percent emergence rate of sensitive seeds by Day 90. The manure amendments were comparable to the commercial greenhouse substrate in growth. Thus, a bio-based value-added medium that is nontoxic and suitable for potting mix was produced from SPCL wastes, remediating the process waste.

In order to evaluate the effect of extractives on particle bonding, pellets were produced from extracted and nonextracted Scots pine sawdust in a laboratory piston press pelletizer. In the experiment, the raw material and process parameters were fresh (nonextracted) and acetone-extracted sawdust, sawdust moisture content (6% and 12%), piston pressure (70 and 150 MPa), and press temperature (100°C and 180°C). The resulting pellets were evaluated and compared for density, compression strength, and moisture sorption. The relationship between factors and responses was evaluated by partial least squares regression. In the present study, it was found that pressure and temperature had a positive effect on both pellet density and compression strength. Extracted sawdust gave pellets with a higher density and compression strength than pellets made from nonextracted sawdust. Moisture sorption between the produced pellets showed no significant differences. Results of this study provide a plausible explanation for why pellets produced from stored sawdust with low amounts of extractives have better strength properties than pellets produced from fresh sawdust.

The aim of this study was to determine the effects of ebru, a traditional Turkish art of marbling, on some physical properties of various varnishes. Scots pine (Pinus sylvestris L.), Turkish oriental beech (Fagus orientalis Lipsky), and medium-density fiberboard specimens were used as substrates. Each sample surface was first stained by ebru or a commercial wood stain (wood paint), dried, and then covered with one of a variety of varnishes. Nitrocellulose-based, alkyd-based synthetic, water-based, and polyurethane-based varnishes were applied as two consecutive topcoats. Adhesion, hardness, and gloss tests were performed. Results showed that, in general, there was not any statistically significant effect of ebru staining before coating with varnishes. In conclusion, the Turkish art of ebru can be utilized on wood and wood-based panels as an artistic and decorative staining technique.

Red oak, sweetgum, and yellow-poplar lumber was machined into 3 by 15 by 150-mm (tangential by radial by longitudinal) miniature beams. Moisture content was determined from a subset for calculating the ovendry weight of test samples prior to treatment. Samples were weighed, water saturated, and subjected to a partial hydrolysis at 150°C for 30 minutes in 1 percent sulfuric acid, water, or 1 percent sodium hydroxide solutions. Untreated controls were also used. The beams were ovendried to a constant weight, and then the modulus of elasticity, density, and mass loss (ML) were determined. Modulus of elasticity values were corrected to eliminate density variation by calculating the specific modulus of elasticity (SM) for property comparisons. The species and treatments interacted to significantly affect SM. Sweetgum produced a lower SM in all treatments, and the water treatment consistently reduced SM. The species and treatment factors acted independently of one another with respect to ML. Sweetgum lost significantly more mass than the other species, likely because of corresponding reductions in holocellulose. An acid treatment produced the greatest ML.

Laminated utility pole crossarms constitute one of the potential industrial products that can be produced from decommissioned wood utility poles. A previous report evaluated the mechanical properties of laminated utility pole crossarms made from decommissioned chromated copper arsenate (CCA)–treated southern pine (Pinus spp.) utility pole wood, untreated virgin wood, and a mixture of virgin wood and decommissioned utility pole wood. In particular, the bending strength, stiffness, and acoustic properties were assessed after pentachlorophenol (penta) retreatment. This study evaluated CCA and penta retention, glue-line shear, and glue-line delamination of the laminated crossarms. The results of this study show that, after penta retreatment, penta retention increased in correlation to the presence of increasing numbers of treated wood plies in the beams. All the laminated crossarms met the minimum shear strength requirement of 8.60 MPa, which is specified in American Society for Testing and Materials (ASTM) Standard D2559. Most of the laminated crossarms (22 of 24) showed a delamination average of less than 5 percent. However, none of the beams met the individual glue-line delamination requirement (1%) of ASTM Standard D2559. More glue-line delamination was found between two utility pole wood plies and between a utility pole wood ply and a virgin wood ply than between two virgin wood plies. Delamination could be a concern for utility pole wood laminated crossarms to be used in an adverse environment. A better gluing system is needed to improve the delamination performance of utility pole wood laminated beams for exterior applications.

Research on fire retardant–treated wood and wood-based composites has been conducted in China for over two decades. Although many kinds of fire retardants for wood and wood-based composites have been studied, the focus is still mainly on compounds or mixtures containing phosphorus, nitrogen, and boron, which can be used in a water solution for solid wood impregnation. Fire-retardant treatment methods for wood-based panels are either pretreatment of veneers, fibers, particles, or strands before hot pressing or impregnation of waterproof panels with fire-retardant solutions. Though attempts have been made in laboratories and factories to mix the fire retardants with glues, it has proven very difficult to spray the glue smoothly and to deliver effective amounts of fire retardants during the manufacture of panels. The mechanisms of phosphorus–nitrogen–boron fire retardants have been investigated systematically. The results indicate that the phosphorus–nitrogen compounds and the boron compounds are highly synergistic in effective fire-retardant formulations. The catalytic charring effect of a fire retardant on wood is a key factor in its efficacy. A chemical fire-retardant mechanism for boric acid is also proposed.

Research on fire retardants for wood–plastic composites has been attracting more attention in recent years; however, most results are preliminary because of the difficulty in identifying or formulating a fire-retardant system that is effective for both wood and plastics.

Only preliminary research has been conducted on smoke suppression for wood; innovative efforts will be needed to conduct further research.

China's primary wood-processing industry and wood-consuming sectors have experienced rapid growth in recent years. Plywood is the most important primary wood product in China in terms of consumption, production, and exports. One of China's most important export destinations is the United States, to which China exports not only plywood but also wood in the form of furniture. In this article, we analyze the development of China's plywood industry since the 1990s; provide an overview of the demand, supply, and exports of Chinese plywood; and present the results of econometric models. The Engle–Granger error-correction model was applied to an analysis of annual time-series data from 1993 to 2007. The results suggest that most of the growth in China's plywood demand was primarily driven by the growth in consumer income, while an increase in product price had only a small negative effect. In contrast, an increase in raw material price had a significant negative impact, but end-use sector activity had no significant effect on China's plywood supply. During the same period, the growth in China's plywood exports was due to consumer income growth in the US market. Knowledge of the elasticities and findings presented here can serve as a useful reference for foreign and domestic wood product companies that plan their investments, as well as government agencies and public authorities that plan economic and forest policies.

We successfully tracked the identities of more than 550 selected 13-year-old trees from a Eucalyptus nitens (Deane & Maiden) progeny trial through tree felling, harvesting of butt logs, and sawmill processing to finished sawn boards using a two-stage approach. To track log identity from the standing tree to the log yard, we used a numbered under-bark wooden identification plug, glued into a hole drilled in the trunk prior to harvesting. To track tree identity for individual sawn boards, log-end templates with corresponding tree identification numbers were glued to the log ends before milling. Materials and methods used withstood harvesting and debarking, log transportation, milling, air and kiln drying, steam reconditioning, and final machining. A second study confirmed the success of the under-bark plug method to successfully track 548 selected standing trees through harvesting and transportation to the mill.

This article introduces a comprehensive product development strategy to transform ideas into commercial products. Although there is abundant literature on product development tools and innovation theory, the inconsistency of results in previous studies in innovation theory has not produced compatible theories that can be put into practice. To help overcome this problem, grounded theory was used to build a novel and holistic strategy that connects and relates current product development tools with marketing research, value chain, business process management, and innovation theory. The resulting strategy combines a series of product development tools that can help practitioners to easily identify customer requirements, to develop ideal solutions, and to deploy solutions. The proposed strategy was applied in the wood products industry with successful results. It is expected that this product development strategy will help researchers and practitioners better integrate theory and practice in innovation research.

This article reports the results from a supply chain study in which a performance measurement system for a wood products value stream was developed. We build on findings from a previous study in which the need for supply chain metrics of performance was identified. A five-step method to develop performance measures is suggested as an improvement alternative. Examples of specific metrics for quality and time performance are provided. This approach facilitates collaboration between supply chain partners and provides information that allows a more efficient focus on improvement projects. Supply chain measures of performance are important for seeing beyond a single entity and aligning strategy in the supply chain. Companies that want to integrate their suppliers and customers in their improvement efforts can benefit from the information presented here, because a common set of performance measures is essential in evaluating progress toward a goal.

In this article, we present estimates of regional softwood lumber supply functions in the United States using annual time series data for 1959 to 2009. Seemingly unrelated regression is used in a profit maximization framework to model softwood lumber supply as a function of lumber and stumpage prices, lagged supply, wage rate, and interest rate for the eastern and western United States. The effects of listing the northern spotted owl (Strix occidentalis caurina) as a threatened species and the US–Canada softwood lumber trade dispute are controlled for in empirical estimation. Results show that regional lumber supply is quite inelastic to lumber price and that stumpage price and bank prime rate negatively influence regional lumber supply. Results also suggest that present market supplies of softwood lumber have potential expansionary influence on future supplies, that listing of the northern spotted owl in 1990 reduced the lumber supply in the western region during subsequent years, that the US–Canada softwood lumber trade dispute/agreements favored regional lumber production in the United States during the period from 1996 to 2005, and that supply has declined during the recent period of economic recession.