• Journal of the Korean Wood Science and Technology
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• v.3 no.1
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• pp.50-52
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• 1975

• Journal of the Korean Wood Science and Technology
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• v.10 no.4
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• pp.76-88
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• 1982

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.

• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.59-66
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• 2006

The thermal properties of wood flour, Hwangto, and maleated polyethylene (MAPE) reinforced HDPE composites were investigated in this study. The thermal behavior of reinforced wood polymer composites was characterized by means of thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. Hwangto and MAPE were used as an inorganic filler and a coupling agent, respectively. According to TGA analysis, the increase of wood flour level increased the thermal degradation of composites in the early stage, but decreased in the late stage. On the other hand, Hwangto reinforced composites showed the higher thermal stability than virgin HDPE, from the determination of differential peak temperature ($DT_p$). Decomposition temperature of wood flour and/or Hwangto reinforced composites increased with increase of heating rate. From DSC analysis, melting temperature of reinforced composites little bit increased with the addition of wood flour or Hwangto. As the loading of wood flour or Hwangto to HDPE increased, overall enthalpy decreased. It showed that wood flour and Hwangto absorbed more heat energy for melting the reinforced composites. Hwangto reinforced composites required more heat energy than wood flour reinforced composites and virgin HDPE. Coupling agent gave no significant effect on the thermal properties of composites. Thermal analyses indicate that composites with Hwangto are more thermally stable than those without Hwangto.

• Journal of the Korean Wood Science and Technology
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• v.48 no.1
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• pp.86-94
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• 2020

This study serves as basic research for the development of a new wood-based building finishing material that improved the weakness of inorganic materials such as gypsum board and magnesium board widely used as interior finishing materials and brought out the strength of the wood. The results of evaluating the physical and mechanical properties and the environmental effect related to hazardous substance discharge having manufactured a wood-magnesium laminated composite are as follows. The thermal conductivity and thermal resistance of WML board was improved by about 28~109 percent over magnesium board due to the low thermal conductivity of wood. The adhesive strength of WML board showed a similar result to that of plywood as it exceeds 0.7N/㎟, the adhesive standard of wood veneer which is presented by KS F 3101. Bending strength and screw holding strength were more improved by manufacturing WML board than magnesium board. The WML board manufactured in this study satisfied the criteria for emissions of hazardous substances prescribed in the Indoor Air Quality Control Act, and confirmed the possibility of development as a new wood-based composite material that can replace existing inorganic materials.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.853-856
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• 2006

It is known that cement production not only consumes large amount of energy but also contributes substantially to the green house gas emission. Therefore, there is a demand to develope a new technology to produce energy efficient and environmental conscious cements. The most recent, wood wool ceramic board is being applied in various building material field, for example thermal insulating and acoustic absorption material. This paper focused on improvement of the physical properties for wood wool ceramic board applied inorganic polymer binder. As the result of this experiment, what we could obtain better wood wool ceramic board's properties such as density, water contests, water resistance and band strength, was 0.46, $10{\sim}12%$, 1.9% and $40kgf/cm^2$. This result can be applicable to commercial wood wool ceramic board.

• Journal of the Korea Furniture Society
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• v.13 no.2
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• pp.29-38
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• 2002

Five type boxes, which are from brick, wood panel, charcoal-packed wood panel, plywood panel and charcoal-packed plywood panel, were prepared. Relationship of preservation characteristic of strawberry and change of relative humidity in the boxes were measured. Physical properties and industrial analysis of white charcoal used were also investigated. Physical Properties and industrial analysis showed that charcoal had: 1) $0.62-0.79g/cm^3$ of density, zero of refining degree and 8.6-9.4 of pH; and 2) 1.0-3.0% of moisture content, 1.9-2.9% of ash content, 3.9-5.0 of volatiles and 89.2-93.2% of fixed carbon, indicating high quality. During the experimental period, relative humidity was highest in the brick box and lowest in the charcoal-packed plywood panel box. Weight loss of strawberry was greatest in charcoal-packed wood Panel box and very little in brick box. In the boxes with charcoal, strawberry was preserved for 6 days without mold, but in brick box it was covered with mold in 3 days. From these results, it is suggested that charcoal-packed wood panel can be used for better ecomaterial.

• 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 Applied Science and Technology
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• v.25 no.2
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• pp.160-167
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• 2008

Nanocomposites with polypropylene/clay/wood flour were prepared by melt blending and injection molding. Thermal, mechanical and morphological properties were characterized. The addition of ballmilled clay, compatibilizer and wood flour significantly improved the thermal stability of the hybrids. The tensile modulus and strength of most hybrids was highly increased with the increased loading of clay, maleated polypropylene (MAPP) and wood flour (WF), compared to the PP/WF hybrids. The tensile modulus and strength of most hybrids were highly increased with the increased loading of ballmilled clay, MAPP and wood flour, compared to the hybrids with PP/WF. The transmission electron microscopy (TEM) photomicrographs illustrated the intercalated and partially exfoliated structures of the hybrids with ballmilled clay, MAPP and wood flour.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.10-21
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• 2006

Recycled polypropylene (RPP) - Wood Saw Dust (WSD) composites with and without acetylation of filler were produced at different filler loading (15%, 25%, 35% and 45% w/w) and filler size (300, 212 and $100{\mu}m$). The RPP-WSD was compounded using a Haake Rheodrive 500 twin screw compounder at $190^{\circ}C$ at 8 MPa for 30 minutes. The mechanical properties and water absorption properties of modified and unmodified WSD-PP composites were investigated. Acetylation of WSD improved the mechanical and water absorption characteristic of composites. The decrease of filler size (300 to $100{\mu}m$) of the unmodified and acetylated WSD showed increase of tensile strength and impact properties. The composites exhibited higher tensile modulus properties as the filler loading increased (15% to 45%). However tensile strength, elongation at break and impact strength showed the opposite phenomenon. Water absorption increased as the mesh number and filler loading increased. With acetylation, lower moisture absorption was observed as compared to unmodified WSD. The failure mechanism from impact fracture of the filler-matrix interface with and without acetylation was analyzed using Scanning Electron Microscope (SEM).