Wood and Fiber Science (E-Journal)
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Effect of Plant-Based Filtration and Biotreatment on Toxicity of Bio-Oil Process Water
No full textThis study evaluated physical and biological treatments of bio-oil process water to decrease organic contaminants. A three-sequential-column filtration system compared four treatments: three columns filled with kenaf only; three columns filled with wood shavings only; one column filled with wood shavings and two with kenaf; and one column filled with kenaf and two with wood shavings. The kenaf and wood shavings were composted after filtration. The filtrate water underwent further biotreatment by adding aeration and selected bacteria. After filtration and biotreatment, oil and grease concentrations were decreased more than 80% and toxicity decreased more than 90%. There were no significant differences among filtration treatments. Most of the oil and grease was removed by the first column. Aeration significantly decreased the concentration of oil and grease and toxicity in the filtrate water. Composting of the biofiltration matrices significantly decreased the oil and grease concentrations at Day 45 by 80%
Effect of Vacuum Heat Treatment Temperature on Physical and Mechanical Properties of Eucalyptus Pellita Wood
No full textThis study investigated how vacuum heat treatment influenced the physical and mechanical properties of Eucalyptus pellita wood. The investigated properties included mass loss, oven-dry density, dimensional stability, modulus of elasticity (MOE), and modulus of rupture (MOR). For the study, wood samples were heated under vacuum atmosphere at temperatures ranging from 80 to 280°C for 4 h. The results showed that although the mass loss of wood showed only a slight change below 200°C, there was a sharp increase in loss after 240°C. Oven-dry density of wood decreased slowly with an increase of treatment temperature with decreases of 4.4 and 10.4% compared with the control sample observed at 200 and 240°C, respectively. Conversely, the dimensional stability of samples increased by about 30% at 200°C. As temperatures increased, MOE and MOR initially showed gradual enhancements before declining rapidly. Compared with the untreated sample, MOE increased by 25.2% at 200°C, whereas MOR augmented by 6.5% at 160°C. Vacuum heat treatment temperature between 160 and 200°C would be available for improving dimensional stability and keeping mechanical strength of Eucalyptus pellita wood
Effect of Silver Nanoparticles on White-Rot Wood Decay and Some Physical Properties of Three Tropical Wood Species
Get PDFWood is one of the most widely used materials and is used in many applications. However, decay resistance of wood is limited in tropical conditions. Nanotechnology applications have potential for improving materials. In this study, a solution with a concentration of 50 ppm silver nanoparticles was incorporated by pressure into three commercial species (Acacia mangium, Cedrela odorata, and Vochysia guatemalensis) of Costa Rica. The white-rot fungus (Trametes versicolor) was tested, and some physical properties were also measured. According to the results, synthetized silver nanoparticles (10-25 nm) presented little agglomeration and were adequately distributed. The retention achieved was 25-102 silver mg/kg-1 of wood, varying among species and with presence of sapwood and heartwood. Mass loss was less than 5% in wood treated with silver nanoparticles; thus, the wood was classified as highly resistant or class A. Meanwhile, untreated wood presented losses greater than 20% with white-rot fungi. Also, water absorption capacity decreased for wood treated with silver nanoparticles in the three species tested, and dimensional stability increased for Cedrela odorata and Vochysia guatemalensis treated with silver nanoparticles
Moisture Dependence of Indentation Deformation and Mechanical Properties of Masson Pine (Pinus Massoniana Lamb) Cell Walls as Related to Microfibrilar Angle
No full textTo better understand how microfibrillar angle (MFA) and moisture content influence the mechanical performances of wood at the cell wall level, the nanoindentation technique was used to measure the indentation modulus, hardness, indentation creep rate (ICR), residual plastic deformation (RPD), and elastic recovery deformation (ERD) of Masson pine (Pinus massoniana Lamb) wood cell walls with small (16°), medium (27°), and large (38°) MFA values at 5, 8, and 11% MC, respectively. The results show cell wall elastic modulus was negatively correlated to moisture content, but the specific trend was to some extent affected by the value of MFA. MFA has a negative influence on cell wall elastic modulus across the range of all tested moisture contents. Cell wall hardness decreased significantly with increase of moisture content for all three MFA values, whereas the effect of MFA was insignificant. RPD and ERD of cell walls responded differently to the change of moisture content and MFA. In general, RPD is more sensitive to moisture content than MFA, whereas ERD and ICR are more sensitive to MFA than the low moisture content range as defined in this study
Dyeing of Acetylated Wood with Disperse Dyes
No full textIn this study, fir powder and acetylated fir powder were dyed using a series of disperse dyes under high temperature and pressure and were compared with the dyeing of polyester under the same condition. Acetylated oak and poplar veneer were also dyed as a reference. Unmodified fir powder, acetylated fir powder, and dyed acetylated fir powder were characterized by IR spectra and scanning electron microscope. The effect of pH value and dye concentration on the dyeing properties and fastness was evaluated and compared. Disperse dyes exhibited better dyeability and fastness on acetylated fir powder than on unmodified fir powder. This was because of the differences in the structures of the two fir powders
Property Enhancement of Wood-Rubber Composites by Microwave Treatment of Rubber Particles
Get PDFIn this study, a microwave oven with a frequency of 2450 MHz was used for the surface modification of rubber particles. The samples were treated with five different output powers (160, 320, 480, 640, and 800 W) for six exposure times (1, 2, 3, 4, 5, and 6 min). The influence of the microwave treatment on rubber characteristics was analyzed by Fourier transform infrared spectroscopy. The wood-rubber composites were fabricated using 70% poplar particles and 30% rubber particles. Four regression equations, ie radiation time and power as functions of modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, were developed and a nonlinear programing model was derived to obtain the optimum panel properties. The results from contact angle measurements and microscopic analysis indicated that the surface characteristics were changed after the microwave treatment, improving the mechanical properties of the wood-rubber composites
2010 Status Quo for Life-Cycle Inventory and Environmental Impact Assessment of the Core Sawmill Products in Germany
No full textProduct life-cycle assessment (LCA) is an established tool for supporting decisions on the consumer, business, and policy levels. LCA practitioners are in need of continuously updated average LCA data in line with current methodological developments and consensus for supporting decisions with environmental information. For sawmill products, where large deviations in terms of environmental impact among the many single sawmills are known to exist, detailed surveys on LCA data with high sector representativeness are needed to yield reliable average data. Based on a representative study on German sawmills, this article provides detailed environmental average life-cycle inventory and impact assessment data and variations for the production of the four core products of the German sawmill industry setting a status quo for 2010
Chemical Modification of Fast-Grown Poplar by Urea Formaldehyde and Polyacrylic Resin
Get PDFIn this study, methylolurea and polyacrylic resin were used to modify fast-grown poplar. The dimensional stability and mechanical properties of natural and modified wood were investigated. Also, the modified samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results showed that the chemical modifier was impregnated into the wood inner structure, which improved the chemical and mechanical performance of wood. FTIR demonstrated that the hydroxyl groups of wood were decreased, which decreased the water absorption of natural wood. XRD tests indicated that the crystallinity of wood increased but the structure of cellulose was not disrupted after modification. TGA analysis showed that the thermal stability of the hemicelluloses and cellulose was enhanced after modification. The prepolymer was not only impregnated into the wood cell, but also reacted with the wood fiber. A crosslinking reaction occurred between the wood modifier and wood fiber
Reducing Susceptibility of Heat-Treated Sweetgum and Pine to Mold Colonization by Incorporating Traditional Biocides
Get PDFHeat treatment, an International Plant Protection Convention-approved measure for phytosanitation of wood packaging material, is achieved by maintaining a minimum core temperature of 56°C for 30 min. The heat treatment process is typically effective regarding phytosanitation, although there are concerns regarding the longevity of the protection provided by the heat treatment because the moisture content of the wood is not reduced enough to prevent insect reinfestation or mold colonization. Susceptibility of heat-treated wood to organisms may be mitigated by combining heat treatment with biocides. Commercial formulations consisting of didecyl-dimethylammonium chloride (DDAC) may be utilized separately or in combination with disodium octaborate tetrahydrate (DOT). To study mold growth following heat treatment, a modified mold test was conducted utilizing nonseasoned sweetgum (Liquidambar styraciflua) and southern pine (Pinus spp.) test samples to evaluate the efficacies of three biocide formulations applied in conjunction with the International Standards for Phytosanitary Measures No. 15 standardized heat treatment. The results of this study indicate that in a 4-wk test period conducted at 23.8°C and 85% RH, surface mold grew readily on heat-treated wood material, but surfaces treated with DDAC and/or DOT in conjunction with heat treatment significantly reduced surface mold growth
Life Cycle Impacts of Manufacturing Redwood Decking in Northern California
No full textAwareness of the environmental footprint of building construction and use has led to increasing interest in green building. Defining a green building is an evolving process with life cycle inventory and life cycle impact assessment (LCIA) emerging as key tools in that evolution and definition process. This study used LCIA to determine the environmental footprint associated with manufacturing 38- x 138-mm redwood (Sequoia sempervirens) decking from sustainably managed northern California redwood forests. Primary survey data were collected from four redwood mills that represent 90% of redwood lumber production. The primary data were then weight-averaged on a per-unit basis of 1 m3 of planed redwood decking (380 oven-dry kg/m3) to calculate material flows and energy use. All of the raw material consumption and environmental outputs were assigned to dry planed redwood decking and none to coproducts. The gate-to-gate, cumulative energy consumption associated with manufacturing 1 m3 of planed redwood decking from 1.8 m3 of incoming logs was 1.36 GJ/m3 with 19% of the energy provided by burning wood residues. Emission data produced through modeling the production process found that the estimated biomass and fossil CO2 emissions were 20.9 and 52.9 kg/m3, respectively. Based on the carbon content of redwood of 53%, a cubic meter of 38- x 138-mm redwood decking product stores 201 kg of carbon and if released into the atmosphere would emit 738 kg of CO2. The amount of carbon stored in redwood decking is equivalent to about 10 times the total CO2 emissions released during the manufacturing process. Low carbon emissions during the manufacturing process and carbon storage during the service life of a redwood deck are positive environmental attributes that should be considered when selecting a decking product