• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.673-680
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• 2017

Research and commercialization of wood chips-urethane resin mixtures as paving materials for park trails and tourist attractions are underway. The aim of this study was to expand the use of such paving materials to the playgrounds, where vigorous physical movements occur frequently. For this purpose, the physical properties and safety of the paving material, in which some or all of the wood chips(passing through a 10mm sieve and remaining in a 3mm sieve) were replaced with sawdust, were studied experimentally. Strength, elastic modulus, slip resistance, shock absorption and heavy metal content tests were carried out by varying the mixing ratio of urethane resin, sawdust and wood chip. As a result, in the case of wood chip-resin mixtures with mass ratios of the resin to total mass of sawdust and wood chips of 1.0 and 1.2 and having a ratio of sawdust mass to total mass of sawdust and wood chips of 0-0.4, it was found that the properties satisfied KS F 3888-2. On the other hand, in case of using sawdust only as a woody material, the shock absorbability was below standard, and the mass ratio of resin to sawdust required 1.2 or more to ensure the specified tensile strength.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.528-537
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• 2015

To reuse the waste bone from restaurants or butcher houses, the possibility of using waste bone powder after cooking as a filler for wood adhesives used in manufacturing plywood was investigated. Radiata pine (Pinus radiata D. Don) plywoods were manufactured by using commonly used wood adhesives such as urea-melamine formaldehyde (UMF) resin, urea-formaldehyde (UF) resin, and phenol-formaldehyde (PF) resin and the prepared fillers from cattle bone powder, pig bone powder, and seashell powder. Plywood fabricated by using cattle bone powder, pig bone powder, and seashell powder showed weaker performance in dry and wet glue-joint shear strength and wood failure than those of the plywood with wheat flour. The result showed that it was hard to use only bone powder for the replacement of wheat flour. However, the filler mixed with wheat flour and bone powders showed equivalent dry bonding strength and better water resistance than the wheat flour, indicating that bone powders mixed with wheat flour might be used for the manufacture of plywood. When bone powders were mixed with wheat flour as adhesive fillers the shell powder showed the lowest bonding properties and there was no big difference between the cattle bone powder and the pig bone powder.

• Journal of Conservation Science
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• v.17 s.17
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• pp.19-32
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• 2005

The exterior of Korean traditional wooden buildings have been painted with Danchung of painting method using glue and pigments. However because of losing traditional techniques and materials through the period of colonization and industrialization, many problems are occurring today. Especially after several years from painting, occurrence of scalings and flakings in painting layer is a serious problem. To improve weathering resistance of painting layer caused by stress from the difference of swelling and shrinkage between painting layer and wood plate, was examined by weathering tests. The stress is due to the hydrophilic property of wood, mechanical properties(tensile property and stress relaxation) of painting layer, and priming methods by various binders such as glue, acrylic emulsion(Primal AC-3444), acrylic resin(Paraloid B-72). Because stress relaxation of acrylic emulsion of which glasf transition temperature is below room temperature$(7^{\circ}C)$ is high, painting layers with acrylic emulsion generate no scalings and flakings and are in the most durable state in all weathering tests. Priming method which starts from low concentration to high concentration, is more effective to improve durability than other priming methods.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.71-79
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• 2000

Two linerboards consisting of corrugated board were coated with oxidized starch solutions to investigate the change of their properties and analyze the effect of coating on them. The coating of linerboards with oxidized starch resulted in improvement in the properties related to corrugated board properties by increasing fiber bonding and rigidity. The improvement of ring crush strength by coating was greater in inside linerboard than in outside linerboard. Burst index of linerboards rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in burst index. Coating on linerboards with oxidized starch at low coating weight improved stiffness of them. There were no significant changes in tearing resistance of linerboards by coating of oxidized starch. The coating resulted in increase in air resistance and sizing degree of linerboards.

• Journal of the Korean Wood Science and Technology
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• v.26 no.3
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• pp.33-40
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• 1998

The phenolic acids in needles of five pine species such as Pinus densiflora, P. thunbergii. P. virginiana. P. rigida. and P. koraiensis were analyzed seasionally (March, June, September and December) in order to investigate the resistant factors against pine gall-midge(Thecodiplosis japonensis Uchida et Inouye). The interrelation of resistance to pine gall-midge and the content of phenolic acids in pine needles was investigated in the artificial hybride pine species. The contents of salicylic acid in susceptible species (P. densiflora and P. thunbergii) to pine gall-midge which watered with salicylic acid solution in a pot was determined. The results can be concluded as follows, 1. There was a little change in total phenolic constituents of resistant and susceptible pines seasonally. The each content of benzoic acid, salicylic acid and p-hydroxybenzoic acid in June was the highest through four seasons. 2. In June, resistant species showed higher content of salicylic acid than susceptible species, while the content of gallic acid was the highest in December. 3. Among the 21 artificial hybrids(P. densiflora ${\times}$ P. virginiana. P. thunbergii ${\times}$ P. virginiana), the hybrides of the higher salicylic acid content showed the lower rate of pine gall formation. 4. Pine gall formation of the susceptible species which were watered with salicylic acid solution remarkably decreased.

• Journal of the Korea Furniture Society
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• v.12 no.1
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• pp.11-20
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• 2001

To investigate weathering and surface characteristics of coating film on lumbers coated with Hwangchil(varnish of Dendropanax morbifera), we carried out to investigate the resistance against discoloration, value of crack and surface characteristics of coating films on seven domestic lumbers and those of four introduced tropical lumbers. There was investigated to evaluate the properties of coating films by the varnish of Dendropanax morbifera. There was insignificant correlations between the hardness and moisture contents of each lumber treated by the varnish. There was no significant correlations between the thickness of coating film and the hardness, either. Although we investigated 11 wood species, we found only three species as resistance wood species against discoloration; Diospysos spp., Abies holophylla and Ulmus davidiana. The crack of coaing films was the largest on Zelkova serrata followed by Juglans sinensis, Cercidiphum japonicum, Tectona grands, Ulmus davidiana, Guibourtia tessmannii, Diospysos spp. and Dalbergia latifolia. However, there was no crack of coating films on the lumbers of Juniperus rigida, Prunus serrulata var. spontanea and Abies holophylla. The crack of coating film showed positive correlations with the thickness of coating film and hardness. The surface characteristics of the coating films evaluated on the basis of $R_{a}$ values indicated the lumbers of Ulmus davidiana($0.14{\;}{\mu}m$), Juniperus rigida($0.1 5{\;}{\mu}m$), Guibourtia tessmannii($0.19{\;}{\mu}m$), Dalvergia latifolia($0.20{\;}{\mu}m$) and Diospysos spp.($0.20{\;}{\mu}m$), Cercidiphum japonicum($0.24{\;}{\mu}m$) as good species while there was insignificant differences between softwoods and hardwoods. Tectona grands, Prunus serrulata var. spontanea and Abies holophylla showed rough surface with $1.53~2.63{\;}{\mu}m$ of $R_a$ values. The four kinds of rough indices($R_a,{\;}R_z,{\;}R_{max}{\;}and{\;}R_q$) showed very low correlations with moisture contents with the correlation coefficients. The $R_a{\;}and{\;}R_{max}$ also showed slight relationship with hardness.

• Journal of Conservation Science
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• v.31 no.2
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• pp.125-130
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• 2015

Specific techniques and materials in conservation of traditional lacquer has not been transmitted. This study aims to compare the basic characteristics of the filler which used in the base layer of lacquer conservation. Tohoe(a mixture of lacquer and Clay) and the three kinds of additives which is mixed with Tohoe and Goksu(a mixture of lacquer, wood powder and rice starch) are estimated in drying rate, impact resistance, abrasion. Among those samples, the more amount of clay causes fast dryness speed and worse cracks on the surface. The impact resistance is weakened at high amount of clay. There is no significant differences of impact resistance between both additives that is mixed with the samples and additives. The samples that are mixed with Goksu and additives show high impact resistance. In the polishing test, the more amount of filling powders show higher grinding degree and the sample that are mixed with wood powder and charcoal show higher degree as well. The highest grinding degree is Maekchil and Goksu but the lowest one is the sample of the rooftile powder mixture.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.22-29
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• 2006

On purpose to reduce accumulated moisture and to prevent moisture condensation in a light-frame wall, thermal characteristics and moisture behaviors were investigated for four different wall assemblies; a) typical wall, b) addition of vapor retarder between the insulation and the gypsum board, c) addition of air gap for natural ventilation behind the siding, d) composition with b) and c). Each wall was tested under two climate conditions; 1) $20^{\circ}C$, 50% RH (indoor) and $30^{\circ}C$, 85% RH (outdoor), 2) $30^{\circ}C$, 85% RH (indoor) and $20^{\circ}C$, 50% RH (outdoor).The results showed that the typical wall assembly had poor resistance against moisture intrusion from the inside of building. Outdoor and indoor humidity caused the moisture condensations on the inside of the siding and the back surface of the sheathing respectively. The addition of a vapor retarder did not give significant improvement in preventing the moisture intrusion.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.271-276
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• 2010

In this study, the light-frame wood shear walls according to the sheathing materials was carried out to investigate the shear load performance. Most common sheathing materials are the structural OSB and gypsum board used to consist wall of wood-frame house. Seven different type of specimens are composed of several sheathing materials and shear test was taken to evaluate shear performance by KS F 2154. As a result, shear walls(G12.5/G12.5 and G12.5/OSB) show that maximum shear strength and shear rigidity modulus are 7316N/mm${\cdot}$118.25 N/mm and 11129 N/mm${\cdot}$184.66 N/mm respectively. The shear wall using gypsum board 15mm improve maximum shear strength and shear rigidity modulus about 30%. The shear wall using 15mm gypsum board showed intermediate value in one side specimens. Different types of shear walls could be compared with the shear load performance. Also, nailed joint failure aspects are different to sheathing material and installing method.

• Textile Coloration and Finishing
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• v.34 no.4
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• pp.234-240
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• 2022

Use of processed timber can help reduce environmental damage and the economic burden of resources (important problems with use of raw timber) and can meet the needs of various fields where the sensibility of raw timber is required. Veneer wood is positioned as a high-value-added product due to its luxury and beauty, and it is used in various fields as a building-related material, such as interior decoration, furniture, flooring, building interior materials, and lumber. Dyeing is necessary to enhance the aesthetic appearance of this pattern and to expand its use. Therefore, in this study, we compared and analyzed the dye ability of oak-patterned materials with reactive dyes, and evaluated their performance as interior materials. As a result, the oak pattern was dyed with 9 kinds of reactive dyes and a comparative analysis was performed. The most suitable conditions are 50℃, 2 hours, and 0.5% o.w.f. In addition, evaluating resilience to daylight, resilience to rubbing, fire resistance, and flame retardance, yielded results suitable for use as an interior material. In this study, the dyeability of veneer dyed under various conditions using reactive dyes was compared and analyzed the performance as an interior material was evaluated.