• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.95-99
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• 1996

The bending and compression strength properties of two types Rhus verniciflua specimens, which made of no heat-treated wood and heat-treated wood for urushiol extraction, were measured. The heat-treated specimens were finger-jointed with either resorcinol-phenol or polyurethane resin adhesives, and the vertical type bending strength property was also measured in these specimens. The results obtained are as follows ; 1. The correlation coefficient between the compression strength and specific gravity in the specimens of no heat-treated and heat-treated wood was high. However there was no difference in compression strength property as affected by heat treatment. 2 The correlation coefficient between the bending strength and specific gravity in the specimens of no heat-treated and heat-treated wood was also high. However, there was no difference in bending strength property as affected by heat treatment. 3 The bending test showed high correlation between modulus of elasticity and modulus of rupture for the specimens made of no heat-treated and heat-treated wood. However, there was no difference in bending strength property between the specimens made of heat-treated and no heat-treated wood. 4. The efficiencies of bending strength test on the finger-jointed specimens of heat-treated wood with resorcinol-phenol and polyurethane resin adhesives were 0.85, 0.81. respectively.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.157-162
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• 2014

This study was conducted to examine the functionality of the fire retardant treated wood. The hygroscopic property, leaching resistance, metal corrosive efficacy and gas toxicity of retardant treated wood were analyzed. Sodium silicate was penetrated to the wood for making fire retardant treated wood. The subsequent treatment agents such as boric acid, ammonium borate, di-ammonium phosphate were treated after sodium silicate treatment due to fixation. As results for the test, the leaching resist was improved by subsequent treatment. The fire retardant combination such as sodium silicate, boric acid and di-ammonium phosphate showed high hygroscopic property, metal corrosive efficacy. The gas toxicity was also satisfied KS standard.

• Journal of the Korean Wood Science and Technology
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• v.29 no.2
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• pp.118-125
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• 2001

In this study, it was examined the characteristics of bending property of red pine(Pinus densiflora S, et Z.) related to slope of grain. At first, we have investigated the characteristics of wood species for bending property. At second, it was examined the relationships between grain angle and its related bending property. Specimens were made following to grain angle $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $90^{\circ}$, respectively. Dimension of wood materials was $10mm(T){\times}20mm(R){\times}350mm(L)$. Microwave irradiation time for bending process was 30, 60, 90, 120 seconds. The result of this study were as follows ; 1. Grain angle of wood was closely related to Young's modulus on bending process. In the process of bending with various grain angle, wood bending was easily proceed on the high grain angle range. 2. However, the strength of bent wood was very weak when the grain angle was high. Therefore, it was considered suitable grain angle for bending was existed. 3. The characteristics of wood properties for wood bending were very different among wood species.

• Journal of the Korean Wood Science and Technology
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• v.42 no.1
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• pp.78-87
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• 2014

It was examined the key criterion of the time of property revelation as Uljin-Geumgangsong wood. For this purpose, we investigated in physical properties in pine wood (Pinus densiflora Sieb. et Zucc.) and representative Uljin-Geumgangsong wood (Pinus densiflora forma erecta Uyeki). The results are as follows; Air-dry density of Uljin-Geumgangsong wood have higher values over about 20 percent than that of pine wood. And also heartwood rate of Uljin-Geumgansong wood have higher values above 70 percent. The number of vertical resin canals per $1mm^2$ in Uljin-Geumgangsong wood was 40 percent greater than in pine wood. As the average diameters of axial resin canals were 67.8 mm and 67.3~69.9 mm in pine wood and in Uljin-Geumgangsong wood, respectively, there was no significant difference among wood species. There tends to be an increase in diameters as annual rings increase. The number of horizontal resin canals in Uljin-Geumgangsong-1 was approximately 55 percent greater than in pine wood and Uljin-Geumgangsong-2. The number of resin canals in pine wood and Uljin-Geumgangson-2 decreased while it increased in Uljin-Geumgangsong-1 as annual rings increased. No significant difference was found in the number of rays among wood species and between earlywood and latewood of same wood species. As annual rings increased the number of rays decreased in both pine wood and Uljin-Geumgangsong. The heights of rays were greater in pine wood than Uljin-Geumgangsong and no difference was found between earlywood and latewood. In conclusion, rings of tree for the time of property revelation as Uljin-Geumgangsong wood is assumed about more than 150 years.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.87-100
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• 2024

Wood has different properties depending on the species or growth area. Therefore, in order to use wood efficiently, it is necessary to have a proper understanding of the characteristics of wood depending on the species and the appropriate use for them. In particular, in order to effectively use more than 1,000 species of woody plants in South Korea as wood, it is necessary to evaluate the characteristics of various Korean domestic woods and make a database of them. In this study, the anatomical properties (length and width of tracheid, cell wall thickness), physical properties (specific gravity and shrinkage), mechanical properties (bending strength, compressive strength, tensile strength, shear strength, hardness), and chemical composition (ash, extract, lignin, total sugar content) of Korean red pine which was grown in Pyeongchang-gun, Gangwon-do, South Korea were evaluated.

• Journal of the Korea Furniture Society
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• v.27 no.2
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• pp.91-95
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• 2016

This study was conducted to investigate the relationship between water absorption (or hygroscopic property) and growth rate of rubra oak (Quercus rubra) from 5 different origins of seed (Carleton, Simcoe, Chatham, Bancroft, Unknown). Water absorption at cross section of Quercus rubra was $0.43{\sim}0.92g/cm^2$ and the property was not related with growth rate. Overall equilibrium moisture content of rubra oak were 11.35~11.56% and 15.15~15.83% at $40^{\circ}C$ with 75% and 90% relative humidities, respectively. There was no relationship between growth rate and moisture content(hygroscopy) in rubra oak. Based on the results, Rubra oak can be classified as a low hygroscopic wood grade, and thus might be a good raw material for furniture productions owing to its superior dimensional stability.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.21-28
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• 2005

For the proper conservation of wooden cultural properties, non-destructive evaluation (NDE) method, which can be used to quantitatively evaluate the internal state of wood members, are needed. In this study, an ultrasonic CT system composed of portable devices was attempted, and the capacity of this system was verified by reconstructing the CT images for two phantoms and two artificially defected specimens. Results from this study showed that the sizes of detected defects were enlarged and the shapes were distorted on the CT images. Also, the positions were shifted somewhat toward the surface of specimen, which is regarded due to the anisotropic property of wood. Compared to the filtered back-projection method, SIRT (simultaneous iterative reconstruction technique) method was determined to be more efficient as the algorithm of image reconstruction for wood. A new ultrasonic CT system is thought to be used as a NDE method for wood. However wood characteristics and wave diffraction within wood made it difficult to accurately evaluate the size, shape and position of defects. To improve the quality of CT image of wood, more research including the relationship between wood and ultrasound is needed, and wood properties should be taken into consideration on the image reconstruction algorithm.

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.761-769
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• 2019

In modern societies, people spend most of their time indoors and the temperature and humidity controlled by electrical appliances have a considerable effect on their emotions and health. However, improper operation of the artificial facilities frequently creates substances that are harmful to our body. The importance of controlling the natural humidity of interior materials has therefore attracted significant attention. This study was aimed at quantifying the hygroscopic property of some interior finishing wooden materials. Dried and heat-treated yellow poplar (Liriodendron tulipifera) lumbers, oriented strand board, and plywood were selected for this experiment. The moisture adsorption and desorption rates of wooden materials were measured (ISO 24353). Furthermore, the effects of morphological, physical and chemical factors, such as surface microstructure, roughness, and functional groups, on the hygroscopicity were evaluated. The results of this study should contribute to improved accuracy of hygroscopic-property assessments performed on wooden interior materials.

• Journal of the Korea Furniture Society
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• v.15 no.1
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• pp.9-16
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• 2004

Five type boxes manufactured from cement(A), wood panel(B), charcoal-packed wood panel(C), plywood panel(D) and charcoal-packed plywood panel(E) were prepared. Relationship of preservation characteristic of strawberry and relative humidity, and properties of thermal and sound insulations in the boxes were examined. During the experimental duration, relative humidity in the cement box was highest and lowest in the charcoal-packed wood panel box. Weight loss of strawberry was greatest in charcoal-packed wood panel box and very little in cement box. In the boxes with charcoal-packed wood panel box and very little in cement box. In the boxes with charcoal, strawberry was preserved for 10 days without getting mold, but in cement box it was covered with mold in 3 days. The charcoal-packed boxes showed higher thermal insulation property than the cement box. There were no significant differences in the property of sound insulation among the 5 type boxes. Consequently, it is suggested that charcoal-packed wood panels can be used for a better ecomaterial.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.526-538
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• 2016

Fumigants are used worldwide for control of biological agents that damage wooden cultural property. To establish a policy for fumigant use, biological evaluation of insects and microorganisms considering many factors is required. This study was performed to evaluate biological sensitivity and wood penetration of three fumigants applied for control of biological agents that damage wooden cultural properties in Korea. Among these, methyl bromide and ethylene oxide can control insects and fungi when exposed directly. However, they were unable to completely control biological agents within deeper parts of wood. Ethanedinitrile, which was developed as an alternative fumigant, exhibited outstanding wood penetration and biocidal efficacy. Further research involving various environmental conditions is warranted.