• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.655-662
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• 2019

This study evaluated the multi-bonding performances of timbers as well as those of reinforcement and timber to obtain data for preparing guidelines regarding the use of timbers as large structural members. For the multi-bonding performances of timbers, four types of bonding surfaces were prepared according to the pith position. For the bonding performances of FRP (fiber-reinforced plastic)/steel plate and timber, a total of 11 types of specimens were produced for the selection of the appropriate adhesive. The bonding performances of the produced specimens were evaluated through a water soaking delamination test, a water boiling delamination test, and a block shear strength test. The test results showed that the bonding strength of the bonding surface according to the pith position was highest in the specimen for which the two sections with the pith at the center of the cross-section on timber and between the bonding surfaces (the tangential and radial sections were mixed) were bonded. Furthermore, the specimens for which the section (radial section) with the pith on the bonding surface of the timber was bonded showed a high delamination percentage. The results of the block shear strength test showed that the bonding section did not have a significant effect on the shear strength, and that the measured wood failure percentage was higher than the KS standard value. The PVAc adhesive showed the highest bonding strength between larix timber and GFRP (glass FRP). Furthermore, the epoxy and polyurethane adhesives showed good bonding strength for CFRP (carbon FRP) and structure steel, respectively.

• Fire Science and Engineering
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• v.34 no.4
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• pp.13-21
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• 2020

This study tested the wood used in building interiors; each type had various incident heat fluxes based on their thickness. The combustion characteristics measured were effective heat of combustion, heat release rate peak and arrival time, maximum average rate of heat emission, and piloted ignition temperature. The wood specimens used in the experiment were 4.8 to 18 mm thick. 25, 35, 50, and 60 kW/㎡ were applied to the incident heat flux that the wood specimens were exposed to. The wood specimens tested were two types of medium-density fiberboard (each with a different density), treated red pine, particle board, and plywood. A comprehensive comparison of different fire characteristics was conducted to analyze the fire patterns corresponding to each type of wood in this way, the risk of fire was studied. The risk of fire was particularly high for particle board. The results of quantifying the fire characteristics of the types of wood studied could function as important input data with which to calculate the fire load of composite combustibles.

• Polymer(Korea)
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• v.39 no.1
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• pp.46-55
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• 2015

There is a limit for deforestation in order to keep the environmental cycle undisturbed. The heart of the paper is to replace the wood to a maximum extent to obtain a sustainable environment. This research aims at new natural composites in which treated hemp fiber used as reinforcement, synthetic cellulose used as particulate to improve the adhesion between matrix - fiber interface and Epoxy LY556 acted as matrix fabricated by hand layup technique. The density, water absorption, tensile properties, impact strength, hardness, flexural properties and compressive properties have been evaluated under ASTM standards and compare the results with existing materials such as wood, aluminium, etc., The composite hemp fiber reinforced polymer (HFRP) could be exploited as an effective replacement for wood and it would be suitable for automotive applications by comparing results.

• Journal of the Korea Furniture Society
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• v.17 no.2
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• pp.49-56
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• 2006

This research was carried out to examine the FIR (far-infrared rays) emissivity and emission power of five types of flooring board by the mixing ratio of charcoal and loess, and the physical property of five types of injected flooring board by the amount of mixture. Type D was appeared the most high value of FIR emissivity and emission power. But there was a little difference among the five types of flooring board values. In physical properties, control type flooring board and injected flooring board showed a similar tendency. Among the domestic trees, all of hard wood seems to be used to surface wood for strong hardness flooring board. But a coniferous tree was not.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.385-390
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• 2010

This study was carried out to manufacture very thin natural elm veneer overlaid charcoal board for enhancing aesthetic value of charcoal board for the indoor application, and to use the advantageous properties of the charcoal as a building material for solving the sick house problem. The thin elm veneer had 26.9% opening ratio. The experiment results showed that the spreading area and the nonvolatile content of adhesive did not affect the gas adsoprtion of fancy veneer overlaid charcoal board. The natural thin elm veneer overlaid charcoal board enhanced not only the aesthetic beauty but also showed the same gas adsorption by the charcoal board.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.251-256
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• 2010

주거 건축 및 가구산업의 자재로써 합성목재(Wood-Plastic Composites)는 점차 각광받고 있다. 본 연구에서는 합성목재의 연소특성을 살펴보기 위하여 한계산소지수 측정(ASTM D2863) 및 콘칼로리미터 시험(ISO 5660-1)을 실시하였으며 또한 일반목재인 적송(red pine)과 방부 처리를 한 방부목에 대하여도 동일한 시험을 통하여 합성목재와 연소특성을 비교 검토하였다. 한계산소지수 측정결과 합성목재가 적송 및 방부목에 비해 가장 낮게 측정되었다. 콘칼로리미터 시험결과 합성목재의 열방출률값이 가장 빨리 피크치에 도달하였고 점차적으로 감소하였다. 합성목재의 최대 열방출률 값 및 평균 열방출률 값은 적송 및 방부목에 비해 가장 높게 나타났으며 총 방출열량 또한 가장 높게 나타났다.

• Resources Recycling
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• v.8 no.4
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• pp.57-63
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• 1999

Wood-Polymer Composites (WPC) m s prepared irom recycled films of agricullural use and wood wastes, and LLDPE and neal PE resin mlxlurr war also utilized in order to cornpiue the praperlies. Molc~ca nhydride (MA) and dicumyl peroxide were used as an adheslon pmmoler and an il~lliatotor~, .espcmivelyT. ensile prapenies of W Cw zrc measured via lenslle test as a funclieu of woad lille~m d MA contmt, and rractu1.e surface was also mvestigaled wilh SEM. As the content of wwd tiller mcreased, clongauon deneased bul modulus increased However, tensile slrength OI WPC increased only when MA war used, and 1 wt.% of MA may be hgh enough to increase the tensile properties. The tensilc ptopcrlies af WPC prepwed from recycled PE films were &nost same as thosc of neal PE resin mixture.

• Structural Engineering and Mechanics
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• v.20 no.2
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• pp.173-189
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• 2005

The paper presents a finite element model for studying timber-concrete composite beams under long-term loading. Both deformability of connection system and rheological behaviour of concrete, timber and connection are fully considered. The creep of component materials and the influence of moisture content on the creep of timber and connection, the so-called "mechano-sorptive" effect, are evaluated by means of accurate linear models. The solution is obtained by applying an effective step-by-step procedure in time, which does not require storing the whole stress history in some points in order to account for the creep behaviour. Hence the proposed method is suitable for analyses of composite beams subjected to complex loading and thermo-hygrometric histories. The possibility to accurately predict the long-term response is then shown by comparing numerical and experimental results for different tests.

• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.67-78
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• 2006

Modification of polylactic acid (PLA) and 10% maleic anhydride (MAH) with 15% dicumyl peroxide (DCP) based on MAH weight was conducted in the kneader at $160^{\circ}C$ and 30~70 rpm, for 15 min. The resulting MAH-modified PLA (PLA-MA) was then evaluated as a compatibilizer for PLA-wood flour (WF) composites. The FTIR and $^1H$-NMR analysis gave evidence of PLA-MA formation. After kneading and reacting with MAH and DCP, the number (Mn) and the weight average (Mw) molecular weights of PLA decreased as compared to the original PLA. The presence of WF in the composites decreased the tensile strength and several other physical properties. The higher the WF loading resulted in the greater the reduction of tensile strength. An addition of 10% PLA-MA as a compatibilizer to the composites improved the tensile strength and several other physical properties, increased the flow temperature, and decreased the melt viscosity. The improved composite revealed 1.42 times increased in tensile strength but not over PLA alone, and absorbed considerably less water compared to those of the composites free-compatibilizer.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.475-479
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• 2012

Thermal energy storage (TES) systems using Microencapsulated phase change material (MPCM) have been recognized as one of the most advanced energy technologies in enhancing the energy efficiency and sustainability of buildings. We examined a way to incorporate MPCMs with building materials through application for wood-based flooring. Wood-based flooring is commonly used for floor finish materials of residential buildings in Korea. However, wood-based flooring has not performed the characteristic of heat storage. This study is aimed at manufacturing high thermal efficiency wood flooring by increasing its heat storage using MPCM. As a result, this study confirmed that MPCM is dispersed well in adhesive through the scanning electron microscopy analysis. From the differential scanning calorimetry analysis, it can be confirmed that this composite has the characteristic of a thermal energy storage material. Also, we analyzed how this composition was formed by physical combination through the Fourier transform infrared analysis. Also, we confirmed the bonding strength of the material by using the universal testing machine.