Wood and Fiber Science (E-Journal)
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Performance of Bamboo Fiber Core Board as Sofa Cushion Material
Full text linkBamboo fiber is a resourceful and environmentally friendly elastic material, therefore, its application in sofa upholstery material minimizes the environmental problems associated with traditional polyurethane foam. In order to explore the feasibility of bamboo fiber core board as the sofa cushion material, the indentation hardness, support factor, deformation recovery, and constant-load impact fatigue loss of two types of Bamboo Fiber Core Board were analyzed. The mechanical properties of two types of bamboo fiber core boards were compared with polyurethane foam commonly used as padding material for sofa upholstery. The results showed that, compared with the Moso bamboo fiber core boards, the yellow bamboo fiber core boards had better resilience, lower indentation hardness, better support performance, and less performance loss after fatigue. In addition, after fatigue treatment, the thickness loss of yellow bamboo fiber core board was greater than that of PU foam, but the loss of hardness was less, and the loss of elasticity performance was the same as that of medium-soft foam. Moreover, the resilience of the yellow bamboo fiber core board was the same as that of medium-soft sofa foam with a density of 35 kg/m3. Yellow bamboo fiber core board has the possibility of replacing sofa polyurethane foam cushion material in practical applications. This study analyzed the mechanical properties of bamboo fiber core boards and provided a theoretical basis for the application of bamboo fibers in sofa cushion materials
MAGNETIC AND PHYSICAL-MECHANICAL PROPERTIES OF WOOD PARTICLEBOARDS COMPOSITE (MWPC) FABRICATED WITH FE3O4 NANOPARTICLES AND THREE PLANTATION WOOD
Full text linkThis study has the main objective to synthesize in situs Fe3O4 nanoparticles (NPs) in fiber particles of three tropical wood (Pinus oocarpa, Vochysia guatemalensis, and Vochysia ferruginea) using two different solutions of Fe3+ and Fe2+ in an aqueous ammonia solution. The magnetic properties were measured by determining fiber particles' Fe3O4 magnetization parameters (coercivity, remanence, saturation magnetization). The FTIR and XDR spectra were also obtained. After the magnetic wood particleboard (MWPC) was fabricated with 100% magnetic particles (MWPC-100) and a superficial layer magnetized with fiber (MWPC-layer), their physical, mechanics, and magnetic properties were compared. The results showed that Fe3O4 NPs content was similar in two Vochyseas species but higher than P. oocarpa. Ash content was similar in the three species. It was difficult to demonstrate the presence of Fe3O4 NPs in the FT-IR spectrum. The diameter of nanoparticles varied from 51 to 68 nm and the saturation magnetization parameters were low, but these values were higher in P. oocarpa. MWPC showed that the use of NPs decreases the density of P. oocarpa but increases the density of the Vochyseas species. Swelling and moisture absorption increased in the MWPC-100 of P. oocarpa and V. guatemalensis but decreased in V. guatemalensis composite. The internal bond decreased in MWPC-100, but not in the MWPC layer. Hardness increased in the MWPC layer in P. oocarpa, but not in MWPC-100, and this property increased in MWPC-100 and the MWPC layer fabricated with V. ferruginea and V. guatemalensis
Copper migration from treated wood garden boxes into soil and vegetable biomass Part I: The first two growing seasons after installation
Full text linkPressure-treated wood is a commonly used material for constructing garden boxes, and concerns about metal leaching into garden soils and garden vegetables persist among the public. This study describes efforts to quantify copper migration from copper azole-treated garden bed frames into garden soil and vegetable biomass. Two garden bed frames were constructed from copper azole 2 x 12-inch nominal Douglas-fir lumber and two were constructed with untreated Douglas-fir lumber before filling with a mixture of native soil and compost. An assortment of common garden vegetables was planted in identical patterns in each of the beds for two growing seasons. During this 2-yr study, we found no difference in copper concentrations between identical vegetables grown in beds constructed with treated or untreated lumber. After 1 and 2 yr, average copper concentrations in soil 0-25 mm from the bed frames were about 23 ppm and 21 ppm higher than soils in the same location in untreated beds, respectively (p < 0.05, Tukey’s HSD). Elevated copper levels were not detected in beds constructed with treated lumber at 76-102 inches from the frames or the bed center, indicating that metal migration was limited. This study shows use of treated wood garden beds did not lead to increases in copper concentrations in vegetables grown in those beds. Treated bed materials did lose some copper to garden soil but increases in copper are limited to about 20 ppm immediately next to the treated wood frames and were not detectable at any greater distances from the wood
Development of a Continuous Wood Surface Charge Detection Device
Full text linkAlmost all woodworking processes involve mechanical friction and contact electrification, i.e. triboelectrification, between the wood surface and the woodworking tool. An electric charge is transferred from one solid surface to another when two materials come into contact with each other. Currently, there are no continuous inline-capable electrical surface charge measuring devices. The goal of this work was to create a measurement setup that can be used with a variety of woodworking processes.
The proposed continuous surface charge detection (ConSurChaD) device connects an electric fieldmeter (EFM) to a Faraday cage-style measuring box. Individual elements of the box can be mounted or dismounted to fit various wood working processes. The application of electrostatic induction principles permitted quantification of the electrostatic surface charge by measuring the accumulated electric field strength generated, expressed in kV/m. The device was compared to a reference method using a commercial discontinuous detection approach. Measurements were made simultaneously using an electrostatic voltmeter, a hand-held instrument that measured the surface charge in volts. The validation confirmed the accuracy of the ConSurChaD device ensuring the applicability for continuous measurement of electrostatic surface charges. This approach allows for a more efficient and targeted application of triboelectrification to wood surfaces, leading to improved surface coatings and other enhancements.
Characterization of bondlines in cross-laminated timber made with preservative-treated lumber
Full text linkThe number of mass timber construction projects is rapidly increasing in North America but this technology encounters durability issues where termites are present. One method for minimizing this risk is to incorporate termiticidal treatments into mass timber elements. This study examined the impact of pre and post layup treatment of cross laminated timber (CLT) on bond line integrity. Douglas-fir 2 × 6-inch lumber or CLT panel sections were pressure treated with 1) borates or 2) (PTIP), or 3) dip treated with a mixture of propiconazole, tebuconazole and imidacloprid + borate (PTIB). CLT panels were manufactured using melamine formaldehyde (MF) or polyurethane (PUR) resins. The impact of preservative treatment on bondline integrity was tested by delamination and block shear tests. Adhesive penetration was also measured using fluorescence microscopy and surface wettability was measured using a contact angle analyzer. Planing treated lumber prior to use in CLT panel assembly reduced actives by 57—94% compared to unplaned lumber containing the same treatment. Panels made with borate treated lumber were more easily delaminated than panels composed of PTIP treated wood. Microscopic evaluation of CLT bondlines showed greater resin penetration in panels made with PTIP-treated wood; however, penetration was highly variable across specimens. Borate-containing treatments increased surface wettability which may have contributed to reduced treated panel performance. The results help define the challenges associated with incorporating biocidal treatments into panels and identify some mechanisms by which they reduce performance
The effects of wooden dowel species and the end distance of miniflex fasteners on the shear strength capacity of H-Type furniture joints
No full textEffects of the wooden dowel species and edge distances were studied relative to the shear force capacities of H-type furniture joints with minifix fastener under loadings. Melamine coated medium density fiberboard (MDF-Lam), minifix fasteners, and wooden dowels were used for specimen as used in the furniture industry. H-type joint specimens were tested in shear force. This compression tests were applied on 60 pieces of test samples prepared for this study based on the principles of ASTM D 1037-06 (2010). According to the results, the highest shear force capacities were obtained for beech dowel. According to edge distances from end distances, the highest shear force capacities were obtained with 72 mm distance from the edge. In manufacturing of wood composite based H type furniture, the highest shear force capacity values were obtained with the edge distance of 72 mm with oak dowel combination (1649 N), while the edge distance of 90 mm with beech dowel combination (1405 N) gave the lowest shear force capacity values. Furthermore, it was concluded that oak dowel as a substance and the distance 72 mm from the edge as distance could be recommended.
Keywords: Shear force capacity, H-ype joint, end distance, minifix fastener, wooden dowe
Comparison of genetic algorithm optimized and PLS regression density models for Acacia auriculiformis
No full textPartial least squares (PLS) regression models based on genetic algorithm (GA) representative near infrared (NIR) wavelengths for estimating wood properties provide improved calibration and prediction statistics compared to PLS models based on all available NIR wavelengths. However, the utilization of predicted data, obtained from full NIR wavelength and GA selected NIR wavelength models, in a practical application, has not been explored. Our application was to examine radial density variation in Acacia auriculiformis Cunn. Ex Benth. clones at a resolution of 10 mm. One hundred and forty A. auriculiformis samples representing seven clones and two radial positions (adjacent to pith and bark respectively) had NIR hyperspectral images (wavelength range 931-1718 nm) collected from their transverse surface. Two PLS density models (all NIR wavelengths and GA representative NIR wavelengths) were developed using 134 NIR spectra extracted from the images. The models were then used to predict density in 10 mm increments of 144 radial samples from the same clones. A PLS density model using only 15 representative NIR wavelengths provided a mean (0.506 g/cm3) which was not statistically significantly different to measured density (0.503 g/cm3), whereas the mean for PLS model using all wavelengths was 0.522 g/cm3. However, the PLS model with 15 representative NIR wavelengths had greater variation (standard deviation of 0.060) compared with measured data (0.052) and the full NIR wavelengths PLS model (0.047). Radial density variation was less than 0.09 g/cm3 for six of the seven clones examined
The influence of different impregnation factors on mechanical properties of silica sol-modified Populus tomentosa
Full text linkThe low density of many fast-growing plantation species results in poor mechanical and flexural properties that limit their usefulness. Supplemental impregnation may represent one method for improving wood properties to create new applications for these materials. The potential for using varying silica sol impregnation processes to improve hardness and flexural properties was investigated on plantation-grown Populus tomentosa. Silica sol-gel impregnation resulted in significant improvements in hardness, MOR, and MOE. The results suggest that these supplemental processes have the potential to create modified woods with a broader range of potential applications
Investigating Storage time to minimize end splitting in Eucalyptus nitens logs
Full text linkThe selection of Eucalyptus nitens (H. Deane & Maiden) logs for higher value-added products is complex due to the presence of radial and longitudinal splits as a result of growth stresses, which reduces their utilization in solid products. The objective of this research was to determine the time limit for the utilization of the logs to increase their use in higher value-added products. Forty trees were used, with two 4 m logs from diameter to breast height obtained per tree. The radius (rt), radial, and longitudinal splits (Rlong) were measured at regular time intervals between turning and 28 da of storage. The relative splitting index was determined as (RMax/rt) per log. From the results obtained, it is evident that there were significant differences in RMax with log height and storage time. The RMax/rt indicator showed significant differences with storage time, showing a better fit than RMax. The linear model that showed the relationship between the external openings of the splits and the longitudinal split had a coefficient of determination (r2) of 0.77. It is concluded that logs should be used before 7 da of storage. Similarly, to increase log yield, radial splitting should be less than or equal to 75% of the radius and logs should be transported in multiple lengths and at a log diameter greater than or equal to 40 cm
WOOD PROPERTIES OF FOUR TROPICAL SPECIES FROM MINING AREAS IN AMAZON, BRAZIL PART 2: DENSITY, EXTRACTIVES, AND COLOUR: Wood Properties of Tropical Species from the Amazon
No full textThe objective of this research was to study the characteristics of four tropical species (Jacaranda copaia, Astronium lecointei, Caryocar villosum and Protium altissimum) stored in different periods. Part 1 of this study described the anatomical features of these species, and Part 2 focused on the physical properties more specifically density, extractives and colour changes along the different times of exposure. Samples were collected from logs exposed for different exposure times (0, 1, 4, 6, and 8 years of exposure). Changes in the basic density were observed for all four species studied, where in Caryocar villosum and Jacaranda copaia the changes were highly related to the period of exposure. For extractives content, both in hot and cold water, alternated according to the storage time, being directly proportional in Jacaranda copaia. The color of the wood of all species tended to darken with time of exposure in storage yards, with the species Astronium lecointei being the one that showed the greatest variation in color over time