Wood and Fiber Science (E-Journal)
Not a member yet
2592 research outputs found
Sort by
The Effect of end Distance and Number of Ready-to-Assemble Furniture Fasteners on Bending moment Resistance of Corner Joints
Get PDFAlthough they are widely used by the furniture industry, ready-to-assemble (RTA) furniture fasteners are a relatively new style of joinery. The object of this study was to investigate the effect of end distance of cam-lock RTA fasteners and nonglued wooden dowels on the splitting and bending moment resistance, respectively, of RTA corner joints. Laminated particleboard, cam fasteners, and wooden dowels were used for specimen construction (as used in the furniture industry). In two studies, L-shaped joint specimens 760 mm long were tested in compression. The first study showed that end splits in panels were eliminated when cam fasteners were located 60 mm from the member ends. In the second study, specimens with two cam fasteners supported by 2, 3, 4, or 5 nonglued dowels were tested. These specimens had significantly higher bending moment resistance than comparable joints that used only cam fasteners but no dowels. Thus, it was concluded that unglued dowels used to position parts for assembly substantially reinforce joints constructed with cam fasteners
Effect of Knife Wear on the Gluability of Planed Surfaces of Radiata Pine
Get PDFThe objectives of this study were to evaluate the effect of knife wear on the gluability of planed surfaces of radiata pine. A conventional process was used to plane samples to four lengths: 200; 10,000; 20,000; and 30,000 m. Cutting-edge recession was measured on the clearance surface of the planing knife for each length. The gluing properties of the planed surfaces were determined for each of the four levels of knife wear using polyvinyl acetate and emulsion polymer isocyanate adhesives. The results showed that the greatest amount of cutting-edge recession on the clearance surface was 65 μm after 30,000 m of planing. The tensile shear strength (TSS) of the lap-joint glue line decreased with knife wear from increased planing. However, TSS was generally greater than the minimum prescribed by the BS EN 204 standard. The effect of knife wear on TSS was more significant after accelerated aging of the glued samples
Medium-Density Fiberboard Produced Using Pulp and Paper Sludge from Different Pulping Processes
Get PDFPulp and paper sludge can be recycled in the manufacture of medium-density fiberboard (MDF) because it contains wood fibers. A comparative study was conducted to evaluate the properties of MDF made from virgin fibers mixed with different pulp and paper sludge sources. A factorial design was used in which factors were mill pulping processes, thermal-mechanical pulping (TMP), chemical-thermal-mechanical pulping (CTMP), and kraft pulping, and percentage of sludge mixed with virgin fibers (0, 25, 50, and 75%). Virgin fibers were obtained from paper birch wood, an underutilized species. Chemical composition, physical characteristics, pH, and buffer capacity of sludge were measured. MDF properties decreased mostly linearly with sludge content. Panel properties negatively correlated with the proportion of nonfibrous material such as ash and extractives. TMP and CTMP sludge sources produced panels of similar quality, and kraft sludge produced the lowest quality. It was concluded that the amount of sludge that can be incorporated into MDF without excessive decrease in panel quality depends on the pulping process. At 25% sludge content, all panels met ANSI quality requirements for MDF used for interior applications
Feasibility of Using Mountain Pine Beetle Attacked Wood to Produce Wood-Plastic Composites
Get PDFPrevious work showed that mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) attacked wood has the potential as raw material for producing wood-plastic composites (WPCs). In the present study, MPB-WPC products were fabricated by extrusion, and the properties of density, flexural, compression, hardness, and nail and screw withdrawal were evaluated. Statistical analyses, including the analysis of variance, multiple comparisons, multiple regression, and the analysis of probability distribution, were conducted to understand the properties of products and the effect of formulations. Results of regression analysis showed significant relationships between the properties and the formulations. Mechanical properties of coupled products were significantly better than those of uncoupled products. The formulation also influenced the behavior and surface condition of the products. In general, greater wood content resulted in a slightly higher density but showed relatively less ductile behavior and failure at smaller deformations. The products with a higher content of high-density polyethylene showed better strength in all aspects, however, a relatively lower stiffness and larger deformation at failure also appeared. Because of the uniform quality of WPCs, the mean value of the properties can be used as a characteristic value for application
Comparison of Copper Leaching from Alkaline Copper Quat Type-D Treated Chinese Fir and Mongolian Scots Pine after Different Posttreatments
Get PDFChinese fir (Cunninghamia lanceolata Hook.) and Mongolian Scots pine (Pinus sylvestris Linn. var. mongolica Litv.) sapwood were treated with alkaline copper quat type D (ACQ-D) solutions at two concentration levels (0.5 and 1.1%) followed by three posttreatments: oven-drying, conditioning in a humidity chamber, or exposed to boiling water. The effects of treatment on copper leaching from ACQ-D-treated wood were investigated by performing tests according to AWPA E11-06. Analysis of chemical composition and pH values were determined to evaluate the effects of wood species on copper leaching. The results showed that copper leaching from ACQ-D-treated Mongolian Scots pine without posttreatment was lower than that of treated Chinese fir. However, after posttreatment, more copper leaching was observed from ACQ-D-treated Mongolian Scots pine than Chinese fir. For example, after conditioning posttreatment, the percentage of copper leached from 1.1% ACQ-D-treated Chinese fir decreased 58.6 to 1.8%, while for Mongolian Scots pine, it decreased 49.5 to 19.4%. The difference was considered to be related to different chemical compositions and pH levels
In-Plane Permeability of Oriented Strand Lumber, Part I: The Effects of Mat Density and Flow Direction
Get PDFThe in-plane permeability was measured for thick, unidirectional oriented strand lumber made from aspen (Populus tremuloides) strands and pressed to five different densities. The press cycle was such that the vertical density profile of the panels was uniform. Specimens were cut from the boards and sealed inside a specially designed specimen holder; this jig was connected to a permeability measurement apparatus and in-plane permeability measured parallel, perpendicular, and 45° to the strand orientation. Permeability decreased markedly with increasing board density. The highest permeability was in the strand alignment direction and lowest perpendicular to it. The permeability in the 45° direction fell between those in parallel and perpendicular to strand alignment. A polynomial equation was fit to the results of each direction with r2 of 0.938 and 0.993. The in-plane distribution of permeability as a function of flow direction was obtained and its vector diagram was lenticular in shape
Is Interior Wood use Psychologically Beneficial? A Review of Psychological Responses Toward Wood
Get PDFOver the past decades, a number of empirical studies have documented that nature or elements of nature in both outdoor and indoor settings can be beneficial for human health and well-being. Wood is a natural product and it is therefore relevant to investigate whether interior wood use might have some of the same beneficial effects. The aim of the present study is therefore to investigate whether interior wood use might be psychologically beneficial by reviewing studies that have investigated psychological responses toward wood. The study also provides a general introduction to theories that can help explain why wood might be psychologically beneficial. Studies related to psychological responses toward interior wood use have generally focused on three different outcomes: 1) perception of wood, including both visual perception and tactile sensation; 2) attitudes and preferences (aesthetic evaluation) of various wood products; and 3) psychophysiological responses toward wood. The review posits that there seem to be similarities in preferences for wood and that people prefer wood because it is natural. In addition, affective responses toward wood seem to be measurable, giving indications of psychological beneficial effects. However, caution should be made in concluding from the review that interior wood use is psychologically beneficial. Thus, theoretical, methodological, and practical implications are discussed and research needs identified
Wood Property Variation in Acacia Auriculiformis Growing in Bangladesh
Get PDFThis study examined the radial variations of wood properties in 11-yr-old Acacia auriculiformis grown in Bangladesh having diameters of 222 ± 38 mm. The basic density, fiber length, and fiber length increment increased up to about 80 mm radial distance from the pith and then were almost constant toward the bark. The compressive strength (CS) increased from the pith to 50 mm and then became nearly constant to the bark. Conversely, the specific compressive strength, the ratio of CS to air-dried density, was almost constant from pith to bark, indicating positive relationships. However, the air-dried density explained only 50% variation of the CS. On the basis of radial variation of basic density, the core wood and outer wood boundary can be delineated at 70 - 90 mm from the pith. Similarly, the fiber length and fiber length increment curves showed that this boundary could be marked at 60 - 90 mm from the pith. The selected wood properties except CS varied significantly among the trees, which indicated the potential of tree selection for wood quality improvement through tree breeding
Effects of Hot Water Posttreatment on Accelerating Copper Fixation in ACQ-D-Treated Chinese FIR
Get PDFThe effects of hot water posttreatments on accelerating copper fixation in alkaline copper quat-type D (ACQ-D) -treated Chinese fir [C. lanceolata (Lamb.) Hook] were evaluated. The rate and extent of copper fixation in treated wood posttreated at 60, 80, and 100°C were monitored by analyzing the copper content in the expressed solution over time. The fixation qualities of copper in treated wood after different hot water posttreatments were evaluated by the AWPA E11-06 leaching test. The valence conversion of copper in treated wood was investigated by UV/visible spectroscopy. The expressing results showed that copper stabilized much faster during hot water posttreatments, especially at 80 and 100°C; more than 90% of copper could be fixed in treated wood in less than 2 h. The valence conversion of copper was highly dependent on the temperature and duration of the treatment. After a 100°C hot water bath of 6 h, more than 40% of cupric copper was reduced to cuprous forms. Based on the results of leaching tests of ACQ-D-treated wood, the best copper leaching resistance was obtained at 100°C; the percentage of copper leaching was reduced to about 12% when posttreated for 9 h. The compressive strength of treated wood was not impaired significantly in that condition
Using an Overall Mass-Transfer Coefficient for Prediction of Drying of Chilean Coigüe
Get PDFA phenomenological model was used to quantify the drying process of Chilean coigüe (Nothofagus dombeyi). This model is based on an overall mass-transfer coefficient, K, which was determined in four laboratory drying runs. The model suitably described the drying of Chilean coigüe lumber of 19- and 30-mm thickness with K ranging from 0.012 to 0.021 ms-1 at a dry-bulb of 60°C and a wet-bulb of 40°C. A preliminary industrial run under somewhat similar conditions in a 100-m3 industrial kiln with 38-mm-thick lumber showing that the drying process could be represented by a K of 0.008 ms-1. The laboratory-scale values of K can be regarded as ideal from which to compare the performance of the industrial unit