Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Wood Science and Technology
Journal Basic Information
Journal DOI :
The Korean Society of Wood Science Technology
Editor in Chief :
Volume & Issues
Volume 35, Issue 6 - Nov 2007
Volume 35, Issue 5 - Sep 2007
Volume 35, Issue 4 - Jul 2007
Volume 35, Issue 3 - May 2007
Volume 35, Issue 2 - Mar 2007
Volume 35, Issue 1 - Jan 2007
Selecting the target year
High-Temperature Drying Characteristics of Wood during Boiling-In-Oil Process
Lee, Hyoung Woo ; Choi, Nak Ju ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 1~6
Boiling-in-oil process was performed to investigate the high-temperature drying characteristics of 25, 50, and 70 mm-thick flat-sawn Douglas-fir lumber. Drying rates, moisture profiles and temperature profiles were monitored. Fully refined paraffin wax was used as drying agent and heated to
. Average drying rates of 25, 50, and 70 mm-thick specimen were 11.6, 6.7, 5.0%/h, respectively. The moisture content differences between cores and ends were 1~2% in 25 mm-thick and 200 mm-long sample and over 10% in 50 mm-thick and 600 mm-long sample.
Effect of Humidity Conditions on Bending Creep Performance of Finger-Jointed Woods
Park, Han-Min ; Byeon, Hee-Seop ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 7~15
To evaluate the durability of finger-jointed woods according to change of humidity conditions, four types of finger-jointed woods glued with different kinds of adhesives and finger pitches were made with Sitka spruce, and the effect of humidity conditions on creep performances was investigated. The shape of creep curves differed among humidity conditions, and the inclination of creep curves was greatest in 85%RH, and lowest in 65%RH. Their creep curves showed a linear behavior beyond approximately one hour, regardless of humidity conditions. The A values of the creep curves fitted to power law increased with increasing relative humidity, whereas the A' values were in order of 30 > 85 > 65%RH unlike the A values. The initial deformation increased with increasing relative humidity, whereas the creep deformation unlike the initial deformation was in order of 85 > 30 > 65%RH, and it was found that the creep deformation of finger-jointed woods indicated the smaller amount in air-dry moisture content rather than in a low moisture content less than 30%RH. Finger-jointed woods with 6.8 mm (L) pitch had the greater creep amount than in those with 4.4 mm (S) pitch in all humidity conditions. The difference of creep amount between both adhesives in all humidity conditions was small. Relative creep at 240 hr was greatest as 62.2~71.9% in 85%RH, and the values indicated 2.1~2.6 times that of 30%RH and 3.0~3.6 times that of 65%RH and were equal or slightly greater than that of solid spruce.
Cross-Sectional Image Reconstruction of Wooden Member by Considering Variation of Wave Velocities
Kim, Kwang-Mo ; Lee, Sang-Joon ; Lee, Jun-Jae ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 16~23
This study was performed as part of a research project aimed at developing an ultrasonic computed tomography (CT) system of wood for field application. In this reports, we investigate the variation of wave velocities on the cross section of real size wooden structural member to confirm the reason of image distortion on CT image of wood, and then proposed a new image reconstruction method by considering the velocity variation on wood cross section. First of all, the effect of wood anisotropy on ultrasonic velocities of wooden members was investigated. Based on the relationship between ultrasonic velocity and annual ring angle, which was obtained from test results of small clear specimens, ultrasonic velocities of each measuring angle were predicted. Next, they were compared with the ultrasonic velocities measured on five wood disks. There were very large differences between predicted and measured results, thought to be caused by the skewing effect of ultrasound and the presence of juvenile-wood. Based on these findings, a new method was proposed to reconstruct cross-sectional image of wood. By using this method, some distortions on reconstructed images could be removed, and defects were more easily and clearly detected. The minimum size of detectable defect was decreased remarkably, from 33 mm to 13 mm. However, the size of the detected defect was enlarged and the position somewhat shifted to the specimen surface on the CT images, which was also thought to be caused by the skewing effect of ultrasound. Additional research has been planned to solve these problems.
Application of Field and Laboratory Emission Cell (FLEC) to Determine Formaldehyde and VOCs Emissions from Wood-Based Composites
Kim, Sumin ; Kim, Jin-A ; Kim, Hyun-Joong ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 24~37
The Korean Ministry of Environment started controlling indoor air quality (IAQ) in 2004 through the introduction of a law regulating the use of pollutant emitting building materials. The use of materials with formaldehyde emission levels above
(JIS A 1901, small chamber method) has been prohibited. This level is equivalent to the
) of the desiccator method (JIS A 1460). However, the
small chamber method requires a 7-day test time to obtain the formaldehyde and volatile organic compound (VOC) emission results from solid building interior materials. As a approach to significantly reduce the test time, the field and laboratory emission cell (FLEC) has been proposed in Europe with a total test time less than one hour. This paper assesses the reproducibility of testing formaldehyde and TVOC emissions from wood-based composites such as medium density fiberboard (MDF), laminate flooring, and engineered flooring using three methods: desiccator, perforator and FLEC. According to the desiccator and perforator standards, the formaldehyde emission level of each flooring was
grade. The formaldehyde emission of MDF was
by the desiccator method and 8.57 g/100 g by the perforator method. To determine the formaldehyde emission, the peak areas of each wood-based composite were calculated from aldehyde chromatograms obtained using the FLEC method. Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde and benzaldehyde were detected as aldehyde compounds. The experimental results indicated that MDF emitted chloroform, benzene, trichloroethylene, toluene, ethylbenzene, m,p-xy-lene, styrene, and o-xylene. MDF emitted significantly greater amounts of VOCs than the floorings did.
Effects of Species on the Isocyanate-bonded Flakeboard Properties
Kwon, Jin Heon ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 38~45
Flakeboards made from ring- and drum-cut flakes of Douglas-fir, hemlock, red lauan and kapur using two kinds of resin levels were evaluated for the selected properties according to flake thickness. The pH and buffering capacity of four species were determined. Those of kapur were extremely different from the other three species. These pH and buffering capacity values result in the poor internal bond strength of kapur flakeboard. The internal bond strength was affected significantly by flake thickness, resin content and species. MOR and MOE in bending strength were maximized at medium drum-cut flake thickness. Screw holding strength was not consistent for flake thickness, but it was influenced by species. Thickness swelling and water absorption of Douglas-fir and hemlock flakeboard were minimized at medium drum-cut flake thickness.
Leachability of Zinc Borate-Modified Oriented Strandboard (OSB)
Lee, Sun-Young ; Wu, Qinglin ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 46~57
The leachability of boron in zinc borate (ZB)-modified oriented strandboard (OSB) from southern wood species was investigated in this study. The leaching experiments were conducted by exposing edge-sealed OSB samples under running water at
for 8, 24, 72, and 216 h. The results from leached samples were compared with those from the unleached controls. Boron leaching of the modified OSB occurred upon the initial water exposure, and the leaching rate decreased as the leaching time increased. Initial boric acid equivalent (BAE) level, wood species, and sample thickness swelling significantly influenced the leachability. There was no consistent effect of polyethylene glycol (PEG) on zinc borate leaching. The glue-line washing within OSB due to thickness swelling of the test samples under water and decomposition of the borate to form water-soluble boric acid were thought to be two possible causes for the observed leaching. The relationship between assayed BAE and leaching time followed a decaying exponential function for zinc borate treated OSB. From the boron/zinc ratio after each leaching period, boron element in ZB was more or less leachable. The material constant of the regression models allowed comparing the leachability of the modified OSB for various wood species. An unified leaching method for treated wood composite materials is needed.
Environment-friendly Adhesives for Fancy Veneer Bonding of Engineered Flooring to Reduce Formaldehyde and TVOC Emissions
Kim, Sumin ; Kim, Hyun-Joong ; Xu, Guang Zhu ; Eom, Young Geun ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 58~66
The objective of this research was to develop environment-friendly adhesives for face fancy veneer bonding of engineered flooring. Urea-formaldehyde (UF)-tannin and melamine-formaldehyde (MF)/PVAc hybrid resin were used to replace UF resin in the formaldehyde-based resin system in order to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. Wattle tannin powder (5 wt%) was added to UF resin and PVAc (30 wt%) to MF resin. These adhesive systems showed better bonding than commercial UF resin with a similar level of wood penetration. The initial adhesion strength was sufficient to be maintained within the optimum initial tack range. The standard formaldehyde emission test (desiccator method) and VOC analyzer were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with commercial UF resin, UF-tannin and MF/PVAc hybrid resin. By desiccator method, the formaldehyde emission level of UF resin showed the highest but was reduced by replacing with UF-tannin and MF/PVAc hybrid resin. MF/PVAc hybrid satisfied the
). VOC emission results by VOC analyzer were similar with the formaldehyde emission results. TVOC emission was in the following order: UF > UF-tannin > MF/PVAc hybrid resin.
Properties of Urea-Formaldehyde Resin Adhesives with Different Formaldehyde to Urea Mole Ratios
Park, Byung-Dae ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 67~75
As a part of abating the formaldehyde emission of urea-formaldehyde (UF) resin adhesive by lowering formaldehyde to urea (F/U) mole ratio, this study was conducted to investigate properties of UF resin adhesive with different F/U mole ratios. UF resin adhesives were synthesized at different F/U mole ratios of 1.6, 1.4, 1.2, and 1.0. Properties of UF resin adhesives measured were non-volatile solids content, pH level, viscosity, water tolerance, specific gravity, gel time and free formaldehyde content. In addition, a linear relationship between non-volatile solids content and sucrose concentration measured by a refractometer was established for a faster determination of the non-volatile solids content of UF resin. As F/U mole ratio was lowered, non-volatile solids content, pH, specific gravity, water tolerance, and gel time increased while free formaldehyde content and viscosity were decreased. These results suggested that the amount of free formaldehyde strongly affected the reactivity of UF resin. Lowering F/U mole ratio of UF resin as a way of abating formaldehyde emission consequently requires improving its reactivity.
Effects of Formaldehyde to Urea Mole Ratio on Thermomechanical Curing of Urea-Formaldehyde Resin Adhesives
Park, Byung-Dae ; Kim, Jae-Woo ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 76~86
This study was conducted to investigate the effects of formaldehyde to urea (F/U) mole ratio on thermomechanical curing of UF resin adhesives with different F/U mole ratios. Thermomechanical curing of these UF resin adhesives was characterized using parameters of dynamic mechanical analysis (DMA) such as the gel temperature, maximum storage modulus, and peak temperatures of storage and loss modulus. As the F/U mole ratio decreased, the gel temperature of UF resin adhesives increased. The maximum storage modulus as an indicator of the rigidity of UF resin adhesives decreased with decreasing F/U mole ratio. The peak temperature of tan
increased with decreasing F/U mole ratio, indicating that the vitrification occurred faster for high F/U mole ratio of UF resin adhesives than for the one of lower F/U mole ratio. These results partially explained the reason why UF resin adhesives with lower F/U mole ratio resulted in relatively poor adhesion performance when they were applied.
The Removal of Heavy Metals from CCA Treated Wood by Immobilized Aspergillus niger
Son, Dong-Won ; Lee, Dong-Heub ; Yoon, Jeong-Jun ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 87~92
For the safe disposal of the end used CCA treated wood, the biological method was studied. Aspergillus niger has been known to be grown on the fresh wood surfaces even on the CCA treated wood surface. Therefore, in this study we estimated the removal efficacy of heavy metals from CCA treated wood by A. niger. The selected fungi, A. niger adsorbed the heavy metals from CCA solution. A. niger removed 95% of arsenic, 55% of copper, and 23% of chromium. From these results, A. niger appeared to be useful for the removal of chromium, copper, and arsenic from the end used CCA-treated wood and the use of A. niger-alginate could be effective.
Phenolic Compounds from the Inner Bark of Paulownia coreana
Si, Chuan-Ling ; Bae, Young-Soo ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 93~99
Paulownia coreana inner bark was collected, extracted in 70% acetone, concentrated under reduced pressure and sequentially fractionated using n-hexane,
, EtOAc and
, then freeze dried to give brown powders. A portion of the EtOAc soluble powder was chromatographed on a Sephadex LH-20 column using a serious of aqueous methanol and ethanol-hexane mixture as eluting solvents. Two phenolic acid,
-courmaric acid and caffeic acid, two isomeric phenylethanoid glycosides, verbascoside and iso-verbascoside, and one epimeric phenylpropanoid glycoside, cistanoside F, were isolated and their structures were elucidated by spectroscopic analysis such as NMR and MS.
Characterization of β-glucosidase from Brown Rot Fungus, Laetiporus sulphureus
Lee, Jae-Won ; Park, Jun-Yeong ; Gwak, Ki-Seob ; Koo, Bon-Wook ; Choi, In-Gyu ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 100~108
-Glucosidase from Laetiporus sulphureus among the enzymes related to lignocellulosic biomass degradation to sugars for using alternative bioethanol production was characterized. The highest activity of
-glucosidase was obtained on cellobiose at shaking culture. For the characterization and purification of
-glucosidase culture solution was concentrated and then purified by FPLC using ion exchange and size exclusion column. According to the results of SDS-PAGE, native PAGE and microfluidic system of purified enzyme, protein band was observed at about 132 kDa. Optimal pH and temperature of purified
-glucosi-dase were 5.0 and
, respectively. In the kinetic properties of
-glucosidase on various substrates such as sophorose, gentiobiose and cellobiose,
was 0.81, 1.07 and 1.70 mM, respectively.
The Production of Methyl Trans-cinnamate in the Submerged Cultures of Tricholoma matsutake Mycelia
Park, Youngki ; Lee, Wi Young ; Ahn, Jin Kwon ;
Journal of the Korean Wood Science and Technology, volume 35, issue 5, 2007, Pages 109~117
Methyl trans-cinnamate is a significant flavor compound of Tricholoma matsutake. Attempts were made to produce this compound by culturing the mycelium using submerged culture. No methyl trans-cinnamate could be detected when the mycelium was cultured in the basal liquid medium. However, the addition of Pinus desiflora extracts to the medium, methyl trans-cinnamate was largely produced. To find out compounds or fractions inducing methyl trans-cinnamate, dichloromethane fraction obtained from the wood extracts of P. densiflora was subjected to column chromatography. Three sub-fractions were obtained from the
fraction. Submerged cultured mycelium treated with sub-fraction 1 has the highest content of methyl trans-cinnamate. Maximum methyl trans-cinnamate
was obtained when the first sub-fraction of dichloromethane fraction of the P. densiflora wood extracts was added to the medium. This indicates that wood extracts of P. densiflora contains inducer of the methyl trans-cinnamate production in the T. matsutake submerged culture.