The results of a mail survey undertaken in mid-2008 to determine the response of wood packaging material (WPM) manufacturers to a universal treatment requirement, similar to ISPM 15 “Guidelines for Regulating Wood Packaging Material in International Trade,” are described. Reactions to a universal requirement were positive (nearly 60% in favor), with larger companies tending to be more positive. Less than 9 percent of respondents indicated they would cease WPM manufacturing. Impacts on pallet pricing were most prevalent at or in excess of $1.00 per unit, with nearly two-thirds of respondents indicating that their customers would accept the true cost of treatment. While only 36 percent would like to see the universal requirement implemented sooner rather than later, these companies were heavily involved in custom heat-treating services and are therefore anticipating the associated marketplace opportunities. The accompanying capital investment in new or additional heat-treating equipment would benefit equipment manufacturers. As the process to create and implement a universal treatment requirement in the United States evolves, policymakers should take into account the current state of the economy, and the WPM industry in particular, and how a change of this magnitude would impact the businesses comprising this industry sector.

Red alder (Alnus rubra Bong.) lumber is widely used to produce furniture and other secondary wood products. Tongue and groove (T&G) paneling is a product with potential niche applications and requires relatively small investments in processing equipment. As such, it represents potential business opportunities for smaller wood products manufacturers in Alaska. This study considered red alder paneling with various levels of character marks, ranging from clear wood to high levels of character. Residential consumers evaluated four panels in Anchorage and Fairbanks, Alaska, and selected their overall favorite panels for potential use in their homes. Character marks, grain consistency, and color also were evaluated for all panels. Statistically significant differences were found between male and female respondents in their attribute ratings for three of the four panels and in color attribute ratings between Anchorage and Fairbanks respondents for the panels with high levels of character. For all four panels, highly significant differences in mean ratings were found among the three attributes (character marks, grain consistency, and color). Market location was generally more significant than gender in influencing attribute ratings. These results suggest that even though strong preferences may exist for clear wood in T&G panels, consumers are able to perceive and rate character mark features differently.

Diameter of the largest limb in the breast height region (DLLBH) of trees is a good predictor of largest limb average diameter, a log knot index used in product recovery studies to predict product grade mix and value. DLLBH was measured on 2,252 Douglas-fir (Pseudostuga menziesii (Mirb.) Franco) trees from nine sites each with three plot pairs established at age 6 to 13 years. One of each pair was thinned, and the other was thinned and fertilized with 224 kg ha⁻¹ N as urea at establishment and every four years thereafter. DLLBH was measured at age 21 to 31 years when BH branches were dead. Fractional polynomials were used to develop models to predict DLLBH. One model (r_adj² = 0.69, root mean square error [RMSE] = 4.86) used only tree variables: diameter at breast height (DBH), total height, height to crown base, taper, and tree social position in the stand. A model that included treatment (if fertilized or not), stand density, and site index was a significant improvement (r_adj² = 0.72, RMSE = 4.62). The tree-variables-only model and the combined tree and stand variables model can be used with individual tree growth models to estimate the distribution of tree DLLBH in a stand for use with process capability analysis to assess conformance with external tree quality specifications. A model using variables measurable with light detection and ranging and knowledge of site index and treatment history was also developed (r_adj² = 0.56, RMSE = 5.78). This model suggests that there is an opportunity to use remote sensing to obtain and map (using a geographic information system) preharvest distributions of tree DLLBH in stands across a landscape for harvest scheduling and silvicultural planning.

Modern sawmills are increasingly like process industries, running continuously with very large volumes flowing through the process every second. This fact makes it vital for every company to utilize its equipment and raw material as effectively as possible to maximize yield and value. The objective of this simulated breakdown study was to analyze the potential to increase volume yield in Swedish sawmills. While the commonly used horns-down position performs well on an average basis, the results show that the optimal rotation position for an individual log is most often found at another position.

Results from extended simulations show that the average volume yield can be increased further by applying the optimal combination of rotation and parallel positioning in cant and deal saw. An increase in average volume yield by 4.5 percentage points (8.6%) would enable a typical Swedish sawmill to produce a further 17,300 m³ of boards per year and thereby increase potential annual income by US$3.7 million per year. This optimization concept requires a preevaluation of every log in order to define the optimal combination of settings.

Some of these procedures must be performed online within a split second to accommodate production speed demands. Modern technology such as industrial x-ray in combination with traceability methods, multivariate models, breakdown simulation software, and high-performance computers enables evaluation and optimization of every log online at full production speed. Sawing machines will need development in order to be able to perform optimization online without loss of production capacity.

The objective of this study was to gain an understanding for drying sawn timber produced from fast-grown, well-managed Queensland hardwood plantations using accelerated drying methods. Due to limited resources, this was a preliminary study and further work will be required to optimize schedules for industrial implementation. Three conventional kiln trials, including two for 38-mm-thick, 19-year-old plantation Gympie messmate (Eucalyptus cloeziana F. Muell.) and one for 25-mm-thick, 15-year-old plantation red mahogany (Eucalyptus pellita F. Muell.), and two vacuum kiln drying trials, one each for 38- and 25-mm-thick Gympie messmate, were conducted. Measurements of final cross-sectional moisture content, moisture content gradient, residual drying stress, and internal and surface checking were used to quantify dried quality. Drying schedules were chosen based on either existing published schedules or, in the case of the vacuum drying trials, existing schedules for species with similar wood density and dying degrade properties, or manipulated schedules based on the results of trials conducted during this study. The findings indicate that both species can be dried using conventional drying techniques with acceptable grade quality in approximately 75 percent of the drying time that industry is currently achieving when drying native forest timber of the same species. The vacuum drying time was 60 percent less than conventional drying for 38-mm-thick, 19-year-old Gympie messmate, although drying quality needs improving. The findings have shown that through careful schedule manipulation and adjustment, the grade quality can be optimized to suit the desired expectation. Additional research is required to further optimize the schedules to ensure acceptable grade qualities can be reliably achieved across all drying criteria and exploit opportunities to reduce drying times further.

Radiata pine (Pinus radiata) peeler cores are classified as a by-product of plywood manufacture and have the potential for development as value-added solid wood products. This article outlines technical and cost analyses of microwave surface modification of radiata pine peeler cores along with the methodology, including measurements of temperature distribution and of preservative uptake and distribution following microwave heating. After microwave treatment, the highest temperatures are observed on the surfaces of the peeler cores. A gradual decrease in temperature is noted with depth within the timber. Chromated copper arsenate uptake after pressure impregnation ranges between 94 and 314 liters/m³. This uptake is three to nine times higher than that of control timber (no microwave treatment). Cost analyses focus on the microwave treatment of peeler cores and indicate that microwave modification costs range from US$0.95 to US$1.23 for one peeler core (i.e., US$29 to US$37 per m³), depending upon electricity charges and the number of working shifts employed.

Western red cedar shakes and shingles were analyzed for extractives after 25 and 33 years of exposure in a field test to better understand the extractives associated with long-term durability. Only minimal concentrations of thujaplicins were found, but plicatic acid was still present in significant quantities. Plicatic acid or other uncharacterized compounds that remain in the wood may play a more important role in the durability of shakes and shingles than previously thought.

The resistance of heat-modified sugi (Cryptomeria japonica D.) sapwood against mold and decay fungi was evaluated under laboratory conditions. Wood specimens were subjected to heat treatment at 180°C for 2 and 4 hours and at 220°C for 2 hours. Changes in lignin and polysaccharide weight percent composition, solubility, and pH of heat-modified specimens were determined. Treatment at 220°C for 2 hours decreased wood polysaccharide content. Heat treatment slightly increased resistance against Rhizopus javanicus and Gliocladium (Trichoderma) virens, but not against Aspergillus niger. The highest temperature used increased resistance to decay by the white-rot fungus Trametes versicolor, but mass losses with the brown-rot fungus Fomitopsis palustris were higher than those with T. versicolor.

Poplar is a fast-growing, short-rotation species that has become a feedstock for pulping and for different composite wood products, such as fiberboard and particleboard. Because of the short rotation, unique characteristics, such as high content of juvenile wood, are present. The objective of this research was to investigate the effects that incorporating poplar in wood chips has on the resultant fiber quality and on fiber-refining energy consumption. Two different quantities of Chinese poplar (Populus lasiocarpa Oliv.) chips were separately mixed into wood chips consisting of a mixture of larch (Larix Mill.) and Masson pine (Pinus massoniana Lamb.). The mixed wood chips went through the refining process in a local medium-density fiberboard mill and refining parameters/conditions, energy consumption, and fiber size were examined at the production site. The results showed that the incorporation of poplar played a favorable role in terms of the fiber size and energy consumption. The higher the poplar content, the better the fiber quality and the lower the energy consumption during refining.

Water resistance properties of kenaf bast fiber bundle (KBFB)–reinforced composites with either unsaturated polyester (UPE) or vinyl ester (VE) matrices, developed in previous research, were studied. The effects of styrene content in UPE resin on the neat UPE resin tensile properties and molding pressure on composite flexural properties were evaluated. The effect of laser and plasma radiation on fiber-matrix interfacial shear strengths was studied. The composites exhibited high water uptake during short- and long-term water immersion. Encapsulation by surface coating and edge sealing improved composite water resistance. Statistical analyses indicated that molding pressures of 5 to 7 MPa were preferable to achieve the maximum composite mechanical properties, and 37.6 percent (wt/wt) styrene in the UPE resin gave the highest UPE matrix tensile properties in the studied range. Laser and plasma radiation of the KBFBs significantly improved fiber-matrix interfacial bonding.

To characterize the variation in bending modulus of elasticity (MOE) and modulus of rupture (MOR), two commercial oriented strandboard (OSB) products were selected. Master panels from multiopening, large hot presses were cut into standard panels of 1,220 by 2,440 mm, and then a total of 3,420 bending specimens were prepared in a continuous order and tested. The variations in bending properties were compared in terms of coefficient of variation (CV) and property differences both between and within master panels. The differences were evaluated by conducting analysis of variance and least significant difference tests. The correlation between MOE and MOR was also investigated. The results showed that the thicker OSB had less variation in bending properties than the thinner product. The variation of MOE (CV = 12% to 16%) was lower than that of MOR (CV = 20% to 22%). Although no significant differences were found in bending MOE and MOR between master panels, significant variations were noted in MOE and MOR within master panels. The differences in MOE and MOR between standard panels varied from 4 to 11 percent, and those along and across the forming line could vary from 8 to 17 percent and from 33 to 59 percent, respectively. The results suggest that product uniformity needs to be improved both along and across the forming line to lower production cost and improve product performance. The relationship between MOE and MOR was linear, with R² around 0.7.

Protection of the fragile honeycomb core material in hollow-core panels has long been a subject of interest for the manufacturers because it is necessary to seal the panel edges to prevent damage. Traditionally this has been accomplished by using edge banding, which has the added benefit of improving panel bending strength and stiffness. This study focuses on evaluating the effects of edge banding on the bending strength and stiffness properties of honeycomb core panels. The honeycomb panels were made with a combination of different face sheet materials (3-mm hardboard or 6-mm medium-density fiberboard [MDF]), rail types (particleboard or yellow poplar [Liriodendron tulipifera]), and rail widths (10 or 38 mm), and had edge-band materials fixed to their long edges using either direct coating, stabilizer edge, or surface folding techniques.

Panels made with the 6-mm MDF face sheet and 38-mm poplar rails had the highest strength properties. To safely apply edge banding to honeycomb core panels, a solid edge reinforcement material is required to prevent the core material from being crushed during the process. The surface folding technique was the best method of edge banding and significantly enhanced the maximum bending moment of honeycomb core panels—more than twice that of panels without edge banding.

The impacts of panel density and strand alignment, and their synergistic effect, on bending strength and stiffness of strand-based wood composites were investigated experimentally. Fifteen unidirectional strand panels with a range of densities were manufactured. Bending specimens were cut at an angle with respect to the alignment direction at 15-degree increments from 0 to 90 degrees. Bending strength and stiffness with extended ranges of density (480 to 672 kg/m³) and strand alignment (0 to 90 degrees) enabled these production factors to be simultaneously investigated. The response of the bending properties to changes in density greatly depended on strand angle. A smaller strand angle exhibited a greater rate of bending property change with density. This synergistic effect provided a supplementary basis for focusing efforts in improving strand alignment on the thin layers near the high-density surfaces to enhance bending properties. The data presented in this article should be especially useful when dealing with unidirectional wood strand/veneer products, such as oriented strand lumber, where strand alignment and density are crucial for the intended application.

Tests were conducted to determine the axial load capacities of knee braces suitable for use in light timber frames constructed with round mortise and tenon joints. To make the knee braces consistent with typical frame construction, the ends of the knee braces were tenoned and did not require machining equipment that was different or more complex than that used for a typical frame. Knee braces with tenons machined perpendicular to the faces of the ends of the braces satisfied these requirements. Three types of braces were investigated; specifically, braces with tenons centrally located on the end-faces of flush-fitting braces, braces with tenons located on the outer edge of the end-faces of flush-fitting braces, and finally, braces with the tenon centrally located on the end-faces of “housed braces,” i.e., braces with the end-faces housed in the sides of the connecting members. Results indicated that all three types of construction had sufficient load capacity to be useful in timber frames constructed with round mortise and tenon joints, but braces with tenons offset toward the outer edge of the end-faces had better structural characteristics than braces with flush ends and centrally located tenons. Finally, knee braces with centrally located tenons and housed ends had substantially greater load capacity than those with unhoused ends.

The objective of this study was to evaluate shear strength characteristics of four commonly used Japanese species, namely, Japanese cedar-sugi (Cryptomeria japonica D. Don), Japanese cypress-hinoki (Chamaecyparis obusta Endl.), false arborvitae-hiba (Thuobsis dolabrate Sieb. et Zucc.), and Japanese larch-karamatsu (Larix leptlepis Gordon), as function of their surface quality. Samples with radial and tangential grain orientations from each species were prepared using a planer and sanded with one of the sandpapers with 80-, 120-, and 240-grit size. A stylus type of equipment was employed to determine surface roughness of each sample before they were bonded in radial and tangential pairs using polyvinyl acetate (PVAc) adhesive at a spread rate of 260 g/m². None of the samples showed any superiority from each other in terms of their surface quality based on three parameters: average roughness (R_a), mean peak-to-valley height (R_z), and maximum roughness (R_max). Average roughness value of both tangential and radial surfaces of the samples sanded with 80-grit sandpaper resulted in significant differences from those of the control samples. The highest shear strength value was 96.1 kg/cm² for the radial karamatsu samples sanded with 80-grit sandpaper followed by tangential hinoki samples with the value of 79.6 kg/cm². In general, the samples finished with 80-grit sandpaper resulted in higher shear strength values than the others tested in this work. It appears that stylus-type equipment can be used to evaluate surface quality of such solid wood samples. Based on the results of this study, sanding of the samples with 80-grit sandpaper improved overall shear strength of the specimens by developing a better glue line between two pieces.