• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.21-28
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• 2007

To analyze the changes in pH and elemental content ratio of wood charcoal and in FT-IR spectra of their surfaces, wood charcoals carbonized from Pinus koraiensis were used. pHs of wood charcoals carbonized from Pinus koraiensis at 300 and $400^{\circ}C$ were 5-27 and 6.80, respectively, whereas they were between 9.25~10.35 for the wood charcoals manufactured between $500{\sim}900^{\circ}C$ From the changes in the elemental ratios of Pinus koraiensis wood charcoal by increasing carbonization temperature, carbon (C) contents increased by elevating the carbonization temperature with the decreasing in content ratios of O and H. The largest changes in the ratio was found between the carbonization temperature 400 and $500^{\circ}C$. Ratios of C, O, H of the wood charcoal manufactured at 300 and $400^{\circ}C$ were 67.7, 28.9, 3.0% and 72.2, 24.9, 2.5%, respectively, while those at $500{\sim}900^{\circ}C$ were between 83.3~90.5, 13.6~9.0, 2.7~0.3%. The surface functional groups of Pinus koraiensis wood charcoals were determined by comparison of FT-IR spectra of the wood powder and the wood charcoal carbonized with the wood powder. The functional groups on the surface of wood charcoals carbonized at 300 and $400^{\circ}C$ were considered to be acidic groups like Lactone, Lactol, Carboxylic acid, Carboxylic anhydride, whereas Pyrone types could be the major functional groups for the wood charcoals carbonized between 500 and $900^{\circ}C$.

• Journal of the Korea Furniture Society
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• v.26 no.3
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• pp.262-266
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• 2015

This study was carried out to analyze the surface color change according to the weathering time. The surface color of material was one of evaluation indexes in exposure experiment. For the purpose, accelerated weathering test was performed with wood. The weathering time level was composed with 0, 500, 1000, 1500 and 2000 hours and color difference was estimated with the color difference meter. The surface color was changed to 500 hours that lightness and redness were decreased and yellowness was increased. However it did not changed after 500 hours. It means that the surface color could be the evaluation index of deterioration of the wood but it means very little after certain time.

• Journal of the Korean Wood Science and Technology
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• v.39 no.2
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• pp.148-155
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• 2011

Thermal treatment techniques are used for modifying wood and wood-based materials to improve dimensional stability and hygroscopicity. This study investigated the effects of press pressure and temperature on density, vertical density profile, thickness swelling and surface hardness of eucalyptus wood boards. The experimental wood boards were prepared from Turkish River Gum ($Eucalyptus$ $camaldulensis$ Dehn.). The surface hardness value increased with increasing press pressure in the treated groups. The application of a higher pressure at the same temperature level increased the amount of swelling of wood. It means that it is not needed for application of higher pressure to enhance the dimensional stability of wood. It is expected that it is possible to produce increased hardness, dimensional stability and durability by application of hot pressing treatment. This research showed that different press pressure and temperature values should be used to improve the performance properties of eucalyptus wood so that the end-use of the wood materials could be expanded.

• Journal of the Korean Wood Science and Technology
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• v.46 no.5
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• pp.449-470
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• 2018

A review of research trends on wood surface protection for exterior use obtained the following conclusions: It has been reported that inorganic compounds such as chrome and copper used as wood preservatives can protect wood from weathering. It has been shown that precoating with hydrophobic substances such as wax and oil, UV absorbers, and HALS (Hindered Amine Light Stabilizers) enhances weathering resistance on the surface of ACQ-treated wood. Opaque coatings of paint/stains and semitransparent stains on the surface of preservative treated wood can increase the synergistic effects on prevention of weathering deterioration. Also the need for repainting periodically for the protection of the preservative treated wood surface has also been suggested. ZnO or $TiO_2$ of fine particles, metal ions such as Co, Cr, Fe, Mn, Ni and Ti, and UV absorbers such as tris-resorcinol triazine derivatives, triazine and benzotriazole were introduced as additives for preventing UV in the transparent coating on wood. Several reports showed that chemical modification such as methylation, acetylation, or alkylations have made some increases the effects of preventing weathering with the increasing weight gain of chemical formulas. In heat-treated wood, there were various contradictory reports on the resistance of weathering, and there were some other reports emphasizing the necessity of painting with UV resistance, which leads to the necessity of more advanced studies.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.3
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• pp.67-73
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• 2010

Pine (Pinus densiflora) and aspen (Populus euramericana) wood meals were treated with ozone at various time schedule in acidic condition. The lignin contents and surface area of the ozone treated wood meals were determined and the enzymatic hydrolysis rate of ozonated wood meals was evaluated. The feasibility of enzymatic hydrolysis of the ozone treated wood meal was obviously influenced with the degree of delignification. After ozone treatment of wood meal for 10min, total pore volume were slightly increased in the surface of wood meal. When wood meals were treated with ozone longer than 10min, few change in the pore volume was observed. However, the area of over $50{\AA}$ of pore size is increased with ozonation time. As a conclusion, the rate of enzymatic hydrolysis of wood is more effective with the pore size distribution than the total pore volume.

• Carbon letters
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• v.3 no.1
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• pp.1-5
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• 2002

The regional bio-wastes available in abundance in India were converted into porous carbon by heat treatment at different temperatures from $650-950^{\circ}C$. The wood retain shapes after pyrolysis though shrinkage occured both in axial and radial directions. The shrinkage in radial direction was found to be more than in axial direction in all woods. The density of woods and chars from these at a given temperature has been found to follow linear relationship. Chars were steam activated at temperature $700-800^{\circ}C$ for different times between 45-240 min. Both the temperature and time of activation with steam has a profound effect on surface area. Chars from softwoods like bagasse and castor oil plant were activated at lower temperature, i.e. $700-750^{\circ}C$ whereas hard wood chars have to be activated at higher temperature around $800^{\circ}C$. The morphology of wood as well as of chars has been studied by SEM. The comparison of the two showed that the nature of porosity in chars depends on precursor morphology, nature and physical state of wood and presence of inorganic compounds in the wood. Hard wood results in cross inter connected pores while softwood leads to fibriller structure. The present studies show that activated carbon with reasonably good surface area (${\sim}1000m^2/gm$) can be prepared from soft wood bio-wastes like bagasse and castor oil plant, while surface area ${\sim}1370m^2/gm$ was achieved from hard wood bio waste of pine wood.

• Textile Coloration and Finishing
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• v.25 no.4
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• pp.314-326
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• 2013

The purpose of this research is to analyze the effects of Dansam and Sappan wood extract to perform combination dyeing on silk fabrics, with respect to color changes, fastness (washing, dry cleaning, perspiration, rubbing and light fastness), and functionality (antibacterial activity and deodorization). Combination dyeing was performed by first combining Dansam with Sappan wood, then Sappan wood with Dansam, in these orders. Given the changes in the combination ratio, pre-mordant treatment was performed. Looking at the surface colors of each dye, Dansam generally produces YR color series, while Sappan wood produces YR, R, and RP color series. The effects of changing the order in which combination dying was performed on the surface colors were as follows. First, combination dyeing (A) was performed by using Dansam before Sappan wood, to produce YR and R color series. Then combination dyeing (B) was performed by using Sappan wood before Dansam, to produce YR, R, and RP color series. By visual inspections, more similar color changes of the combination dyeing were noticed with the post-dyeing material rather than the pre-dyeing material. Therefore, it was presumably confirmed that surface color changes of combination dyeing were greatly influenced by the post-dyeing color. Individual dyeing tests for fastness showed that Dansam was comparatively superior to Sappan wood, which demonstrated lower fastness to washing, dry cleaning, perspiration, and light, relatively. The fastness of combination dyed samples was shown middle, but similar fastness to the post-dye material, The fastness of (B) method was higher than (A) method in the washing and light fastness. This confirms that color fastness from combination dyeing was considerably influenced by the post-dye material. It was found that all dyed samples had a very high bacterial reduction rate of 99.9% and high deodorization rate of 95%.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.68-75
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• 2015

We conducted a thermal compression of domestic Korean pinewood for a use in flooring. For the evaluation of flooring material, we measured dimensional stability and surface hardness of thermally compressed wood. It is possible to make high-specific gravity woods with a range of 0.82-0.92 after the thermal compression with 50% compression set. The surface hardness increased with an increase in the pressing temperature. The highest value of surface hardness was $23.6N/mm^2$, which was obtained from the thermal compressed wood with pressing temperature of $160^{\circ}C$ and 30 minutes of pressing time. However, the surface hardness of woods treated at high temperature of $180^{\circ}C$ or greater decreased. The recovery of thickness decreased with increasing the pressing temperature. For dimensional stability, compression temperature was more dominant than compression time.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.87-92
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• 1996

When cutting 2.0cm-thick red oak and hard maple with an air-jet-assisted carbon-dioxide laser of 2kW output power, maximum feed speed at the point of full penetration of the beam decreased with increasing the angle between grain and cutting direction. Feed speed averaged 3.75 and 3.38 meters per minute for red oak and hard maple, respectively. Gray-level of laser-cut surfaces were analyzed by image analysis system. The highest gray level of laser-cut surface was obtained when red oak was cut parallel to grain by laser. Surface profiler was used to scan the sawn and laser-cut surfaces. Center line average roughnesses of laser-cut surfaces were higher than those of sawn surfaces. Scanning electron micrographs showed the cell walls which were melted by laser.

• Journal of the Korea Furniture Society
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• v.19 no.4
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• pp.229-234
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• 2008

In a previous study, it was revealed that three major softwoods, Japanese pine, Korean pine and Japanese larch, heat-treated at $220^{\circ}C$, could produce high quality dark-colored boards. It is known that heat treatment decreases the hygroscopicity of wood. The hygroscopicity of major domestic softwoods and hardwoods heat-treated at $220^{\circ}C$ was investigated by a saturated salt solution method and compared with that of black and white charcoals. Equilibrium moisture contents of wood decreased with the increase of heat treatment time. Isotherm shapes of wood species were different from those of charcoals. Heat treatment decreases the equilibrium moisture contents of black locust more than those of Korean pine and Japanese larch. It was found that surface hardness of wood is improved by heat treatment to a certain extent, but a longer heat treatment causes thermal degradation, resulting in the decrease of the surface hardness.