• 한국가구학회지
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• 제18권3호
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• pp.205-210
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• 2007

Particleboard(PB) is one of the most commonly used wood-based composite materials, which can be prepared by utilizing any kind of low grade wooden materials like waste wood which contains formaldehyde itself. Therefore, PB have been of considerable interest, in issues regarding the formaldehyde emission problems. Wood wastes are carbonized by the carbonization kiln at $800^{\circ}C$. Charcoal has been known as a formaldehyde adsorber. Thus, in this study, we fabricated PBs with carbonized waste particles cores, to examine the possibility of developing less formaldehyde emitting boards. The physical and mechanical properties were evaluated by Korean Standard (KS F 3104). The moisture content of PBs ranged from 6.76 to 8.36%. Internal bond strengths decreased with the increase in the content of carbonized core particles. Formaldehyde emission showed minimum value at 25% of carbonized core particles, but the emission values increased when the amount of carbonized cote particles increased. When 25% of carbonized core particles was used, PBs met KS F 3104 standard properties.

• Journal of the Korean Wood Science and Technology
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• 제18권2호
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• pp.79-85
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• 1990

Traditional complex joints have used to a wide variety of wooden furniture construction. Dowel joint is the most popular joint s. However design of this joint to meet specified service condition has been hampered by a lack of proven design formulas which can be use to predict their strength. The object of this study is to investigate the withdrawal strength and effect of dowel diameters in wood and wood based materials. The obtained results were as follows; 1. The relationship between withdrawal strength and dowel diameter is found to be linear. 2. Withdrawal strength of medium density fiberboard and Sepetir in end-to-side joints is superior to Antiaris, particleboard and plywood. 3. In end-to-end joints, withdrawal strength of medium density fiberboard is the most superior joint. but Sepetir. Antiaris and plywood have similarly strength and particleboard is inferiority. 4. Withdrawal strength in end-to-end joints of Antiaris and plywood is higher than in end-ta-side joints. But in end-to-end joints of Sepetir. medium density fiberboard and particleboard is similarity in end-to-side joints.

• Journal of the Korean Wood Science and Technology
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• 제45권5호
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• pp.629-639
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• 2017

현재 합천 해인사에 보관되어 있는 고려속장경(일명 팔만대장경)은 역사적 가치나 규모면에 있어서 세계적인 문화재이나 아직도 어떤 수종으로 만들어졌는지 모르고 있다. 중요한 문화재이기 때문에 손상없이 비파괴적으로 수종을 추정하는 방법이 필요하다. 밀도를 알게 되면 수종을 추정하기 쉽다. 유전율식 목재수분계의 원리를 역으로 이용하면 함수율을 알고 있는 목재의 전건밀도를 얻을 수 있다는데 착안하여 연구를 수행하였다. 국내산 100여 개 수종, 122개 재감의 전건밀도를 치수법과 유전율식 목재수분계 추정법으로 구하여 두 계수의 상관관계와 회귀식을 찾았으며 문헌자료를 이용하여 회귀식의 유의성을 검정하였다. 치수법으로 측정한 전건밀도와 유전율식 목재수분계로 추정한 전건밀도는 매우 높은 상관관계를 나타냈다. 이 관계식을 이용하면 팔만대장경판의 전건밀도를 추정할 수 있으며 나아가 수종을 예측할 수 있을 것이다.

• Journal of the Korean Wood Science and Technology
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• 제43권6호
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• pp.784-791
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• 2015

소나무 원판에 polyethylen glycol (PEG)를 주입시키면 건조 중 횡단면할렬을 막을 수 있다. 본 연구에서는 건조온도와 아세틸화처리가 PEG처리 목재에 미치는 효과를 조사하고자 다양한 온도에서 건조한 소나무 원판의 PEG잔류율(PPR)을 아세톤추출과 조습처리를 통해 측정하였다. 아세톤추출법으로 구한 PPR은 열기건조시편이 천연건조시편보다 최하 4배 높았으며, 열기건조시편은 변재의 잔류PEG율이 심재보다 2배 정도 높았다. 이러한 결과는 조습처리실험을 통해 검증되었다. 아세틸화처리에 의한 열기건조시편의 중량변화율(WPC)은 천연건조시편 보다 훨씬 적게 증가하거나 오히려 감소하였다. 무수초산이 잔류 PEG를 용출시켰기 때문으로 밝혀졌다. 따라서 PPR을 높이려면 열기건조하는 것이 천연건조보다 유리하나 아세틸화처리는 대부분의 PEG를 용출시켜 천연건조와 차이를 나타내지 않는다.

• Journal of the Korean Wood Science and Technology
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• 제43권4호
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• pp.429-437
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• 2015

아세틸화처리는 목재의 치수안정성을 높이는 방법으로 알려졌다. 기상처리보다는 액상처리가 중량증가율이 높기 때문에 더 많이 사용된다. 국내산 소나무재와 잣나무재를 액상 아세틸화처리하여 밀도, 휨강도, 치수안정성 등 물리적 성질에 미치는 효과를 조사하였다. 아세틸화처리에 의한 소나무와 잣나무 시편의 중량은 각각 평균 10.4%와 9.2% 증가하였으며, 전건밀도는 각각 평균 6.9%와 4.6% 증가하였다. 소나무와 잣나무 모두 휨파괴계수(MOR)와 휨탄성계수(MOE), 동탄성계수(DMOE)의 변화는 없었다. 아세틸화처리 후 목재시료의 평균 항흡습률(PRH)은 소나무와 잣나무가 각각 20.6%와 13.8% 이었다. 평균 항흡수율(PRA)은 소나무와 잣나무가 각각 20.0%와 8.5%였다. 따라서 아세틸화처리에 의해 소나무의 치수안정성이 향상된 결과를 얻었다.

• 한국조경학회지
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• 제34권2호
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• pp.18-25
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• 2006

This study aims to measure and to analyze the thermal environment characteristics of the various permeable pavement materials such as grass pavement (GREEN BLOCK PARK), stone and grass pavement (GREEN BLOCK STEP), stone pavement (GREEN BLOCK MOSAIC) and wood pavement (WOOD BLOCK) under the summer outdoor environment. The thermal environment characteristics measured in the study includes the changes of surface temperature during the day, changes of the temperature on each pavement layer, and long and short wave radiation of each pavement surface. The experimental condition is based on the data on the hottest temperature (August 5, 2005, $34.0^{\circ}C$) of the you. Some of main findings are: 1) The heat environment was worse on the wood pavements than on the stone pavement. This is mainly due to the low albedo of the wood pavements (0.37) while the albedo value of stone pavements is 0.41. Small heat capacity of the wood pavements also contributes to this difference. 2) The heat environment was worse on the stone pavements than on the turf pavements. This was mainly due to the evapotranspiration of the plant growth layer of the turf pavements. 3) The peak surface temperature was the highest on the wood pavements ($56.1^{\circ}C$). The peak surface temperatures on the stone pavements, the stone-grass pavements and the grass pavements were $43.1^{\circ}C,\;40.1^{\circ}C\;and\;37.9^{\circ}C$, respectively. 4) To improve the thermal environments in the urban area, it is recommended to raise the albedo of the pavements by brightening the surface color of the pavement materials. Further studies on the pavement materials and the construction methods which can enhance the continuous evapotranspiration from the pavements surface are needed.

• 한국가구학회지
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• 제26권2호
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• pp.122-129
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• 2015

In previous study, VOC emission characteristics of coating materials for wood finishing were conducted and results showed that eco-friendly products has about 15~46% lower TVOC emission than typical products. In this study, lower TVOC emitted coating materials were applied on pine and then changes of VOC emission characteristics from pine with treatments were determined. Non-treated pine emitted $604.7{\mu}g/m^2h$ of TVOC that contained 66% of NVOC ($399.7{\mu}g/m^2h$). However, $V_2$ finished pine showed no NVOC emission rather than AVOC emission that consisted of Toluene, Ethylbenzene, m,p-Xylene, o-Xylene, 1,2,4- Trimethylbenzene. All coating materials inhibited ${\alpha}$-Pinene emission which originally from pine, but waterborne stain ($W_1$ and $W_3$) showed lower disruption of that emission. Moreover, $W_3$/wood showed higher NVOC emission such as ${\alpha}$-Terpinol, Terpinen-4-ol which are known as antioxidant substrates. Based on results, VOC emission characteristic of pine was significantly affected by coating materials with negatively in terms of ${\alpha}$-Pinene emission or positively in terms of NVOC emission. Therefore, coating material is important factor for indoor air quality when it would apply on wood products. For the future study, VOC emission characteristic of coated wood will be conducted continuously.

• Journal of the Korean Wood Science and Technology
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• 제23권1호
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• pp.54-60
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• 1995

This paper reports on the changes of equilibrium moisture contents and specific surface areas of Poplar wood(Populus euramericana) for various steam explosion treatments. Equilibrium moisture contents(EMC) and specific surfaces of steam exploded woods were measured under the moisture adsorption course at 25$^{\circ}C$, and compared with those of other materials and wood meals. The EMCs of steam exploded wood meal were 1~5% less in comparison with that of wood meal. In the case of delignified steam exploded wood meal and delignified wood meal, the same tendency was appeared too. But absolute values of EMCs for delignified wood meals were larger than those of the wood meal. For the changes of EMC by the steam exploded conditions, the EMC decreased with the increase of the steam explosion pressure. On the other hand, specific surface areas were calculated from BET plots based on amounts of monomolecular vapor adsorption of various wood meals. Specific surface areas of the wood meal and delignified wood meal were 90~145, 34~90($m^2/g$) respectively, and which were greater in comparison with those of steam exploded wood meals and delignified steam exploded wood meals. From these results, it is considered that the amount of water vapor adsorption was decreased by the increase of the crystallinity, effect of heat treatment, and coating by melted lignin in during the steam explosion.

• Journal of Forest and Environmental Science
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• 제14권1호
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• pp.138-144
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• 1998

표고폐골목의 재활용을 목적으로 폐골목과 정상재의 칩을 일정비율로 혼합하여 얻은 목질보드의 성질을 조사, 검토하였다. 그 결과 폐골목의 목섬유는 정상재보다 다소 짧고 표면이 거철었으며 폐골목 변재부의 밀도는 정상재에 비해 상당히 낮았다. 파티클보드의 두께 팽윤율 및 파괴계수의 시험결과 폐골목을 25-50% 정도 혼합한 경우는 정상재와 비슷한 값을 나타냈다. 결론적으로 폐골목은 파티클보드의 재료로 사용될 수 있고 정상재와의 혼합비율은 25~50% 범위에서 조정되어야 할 것으로 생각되었다.

• Journal of the Korean Wood Science and Technology
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• 제46권2호
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• pp.189-201
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• 2018

Intumescent system is a highly effective flame retardant technology that takes advantage of the mechanism of foaming and carbonization. In order to materialize Intumescent system, it is necessary to use reinforcement material to improve the strength of the material. In this study, we used kenaf as a natural fiber to manufacture intumescent/EVA (ethylene vinyl acetate) composites to improve mechanical and flame retardant performance. Finally two materials with different particle shape are applied to one system. Therefore, the influence factors of the particles with different shapes on the composite material were analyzed based on the tensile test. For this purpose, we have used the tensile strength analysis model and confirmed that it can only act as a partial strength reinforcement due to weak binding force between the matrix and particles. In the combustion characteristics analysis using cone calorimeter and UL 94, the combustion characteristics were enhanced as the content of Intuemscent was increased. As the content of kenaf increased, combustion characteristics were strengthened and carbonization characteristics were weakened. Through the application of kenaf, it can be confirmed that elastic modulus improvement and combustion characteristics can be strengthened, which confirmed the possibility of development of environmentally friendly flame retardant materials.