• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.703-712
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• 2018

The sound absorption property, hand feel, air permeability and pore size of 25 kinds of traditional Korean natural wallpapers (Hanji) were measured and analyzed in this study. The sound absorption rate of Hanji became larger with increasing of frequency beginning from 3.2 kHz, reached 2 times in frequency range of nearby 4 kHz. The sound absorption rate of Hanji was increased as the permeability was lowered and the pore size was decreased. The sound absorption property of Hanji wallpaper could be improved by manufacturing process such as super calendering process.

• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.58-65
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• 2008

집성재의 구조부재로서의 이용에 있어서는 접합철물(connector)과 파스너(fastener)에 의한 접합이 대부분을 차지하고 있다. 이들 접합부의 역학적 거동은 파스너의 지압과 부재의 전단현상으로 설명할 수 있다. 집성재 내의 층재 구성상태에 따른 전단성능, 2면전단 핀접합부의 인발에 의한 전단성능, 실대 기둥-보 2면전단 핀접합부의 모멘트 저항성능을 검토하였다. 집성접착된 부위의 경우, 두 층재간의 보완작용에 의해 밀도 및 전단강도에 있어서도 적층효과를 발휘하였다. 소시험편의 전단강도를 이용한 핀접합부의 2면전단강도와 모멘트 저항성능을 예측할 경우 다소의 보정이 필요할 것으로 판단되었다. 기둥-보 접합부의 모멘트저항성능 예측은 소시험편 전단강도의 10%를 저감하여 이용하면 안전하게 예측가능한 것으로 판명되었다.

• Journal of the Korean Wood Science and Technology
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• 제38권2호
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• pp.101-107
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• 2010

Heat treatment was performed to improve sound absorption properties for four tree species; Tulip tree, Korean Paulownia, Red pine and Costata birch, at temperature of $175^{\circ}C$ and $200^{\circ}C$under vacuum condition. Sound absorption properties of two kinds of boards, which were in radial and tangential sections, were measured under a frequency range of 100 to 3200 Hz by the two microphone transfer function method. It was found that sound absorption properties were increased by heat treatment and the efficiency was higher at $200^{\circ}C$ than that at $175^{\circ}C$. Even Costata birch had a little effect on low temperature of $175^{\circ}C$, $200^{\circ}C$ heat treatment for sound absorption property, the efficiencies of sound absorption were 14, 19%, respectively. The efficiencies of sound absorption ranged 22 to 120% for heat-treated Tulip tree, Korean Paulownia.

• 한국건설순환자원학회논문집
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• 제3권1호
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• pp.80-86
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• 2007

In this study we experimented setting time and basic properties as waste wood fiber and sodium silicate substitution rate to reuse waste wood fiber produced in construction field to wood chip board. To do this construction waste woods were crushed with the size less than 10mm, mixed with the rate of 1:2, 2.5, 3, and added sodium silicate with the rate of 0, 5% of cement content. The results are as follows. As the substitution rate of construction waste wood was increased delay of setting time was also increased, and the batch of adding 5% accelerator had a 13~17 hours faster setting time than non accelerator batch. The compressive strength was lower as wood substitution rate was higher, and as the specific gravity was higher, the strength was also higher. As wood substitution rate was higher, heat conductivity was lower, and as specific gravity was higher, heat conductivity also was higher.

• 자원리싸이클링
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• 제22권2호
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• pp.18-21
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• 2013

본 실험에서는 상압플라즈마에 의한 목분의 표면개질에 대해 조사하였다. 복합재는 목분과 폴리프로필렌을 이용하여 제작되었다(목분 : 폴리프로필렌=55wt% : 45wt%). 상압플라즈마는 carrier gas로 헬륨과 HMDSO를 모노머로 사용하였고 3 KV, $17{\pm}1$KHz, 2 g/min의 조건에서 처리하였다. 폐목분의 인장강도는 상압플라즈마 처리를 통해 18.5 MPa에서 21.2 MPa로 14.6% 증가하였고 단일수종목분의 경우에도 21.5 MPa에서 23.4 MPa로 8.8% 증가하였다. 이것으로 상압플라즈마 처리는 목분의 표면을 개질하여 폴리프로필렌과의 계면결합력을 증가시켜주는 것을 확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제52권4호
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• pp.301-318
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• 2024

Contrary to other materials like metals, glass, etc., wood continuously interacts with the environment, increasing and decreasing its moisture content according to the humidity of the air and changing its dimensions by swelling or shrinking. Water diffusion through laminated solid wood is crucial in wood bonding processes. The adhesive layer might block the diffusion if the water vapor diffusion is perpendicular to the bond line. As a result of this blockage, different proportions of deformation appear on the two sides of the bond line, which causes stresses in the bonded assembly. The question arises of how long the bonded structure will keep its integrity due to moisture diffusion blockage, inevitable tensions appearing in the glue line, and how these stresses could be avoided. With cross laminated timber (CLT) solid wood panel production, this question gains new importance. Despite the relevance, only a limited number of publications are available. Comprehensive research would also be necessary considering both the molecular structure and diffusion properties of the adhesive adjusted to the wood species (covering possible substituting wood species, too). Overall, this review serves as a resource for enhancing our understanding of water vapor diffusion through wood adhesive layers and provides insights that have implications for reducing stresses in bonded wood assemblies and the performance of the bonded group over time. Furthermore, identifying knowledge gaps is necessary to establish the basis for investigating the diffusion property of CLT panels.

• International Journal of Concrete Structures and Materials
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• 제18권3E호
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• pp.165-171
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• 2006

Environment-friendly materials are increasingly used as building construction materials nowadays, and the market share of those is growing. Accordingly, the research and developments in terms of environmental value are progressing steadily now. The main characteristics of environmental products are far-infrared radiation, negative-ion emission, electromagnetic wave shielding, and antimicrobial property. These products are often used in mortar and as spray on the finishing material. Nevertheless, there are hardly any research on the functional properties of concrete, the main material in construction field. Thus, we evaluated such basic properties of concrete as slump, compressive strength and air content while using such functional materials as sericite, wood-pattern sandstone, carbon black and nano-metric silver solution to focus on their functional properties like far-infrared radiation, negative ion emission, electro magnetic wave shielding, and antimicrobial activity in this research. The results indicated that the most useful material in the functional materials was carbon black. Sericite and nano-metric silver solution had a little effect on the functional property. Moreover, although wood-pattern sandstone had very high functional property, it exhibited too low compressive strength to be applied, to concrete as a factory product. Antimicrobial property of nano-metric silver solution in the concrete was not clear demonstrated, but if these specimens were to be aged in $CO_2$ gas for a long time, it might be apparent.

• 펄프종이기술
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• 제42권5호
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• pp.37-46
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• 2010

This study was carried out to develop new application field and obtain the basic data of mixed paper with wood pulp and chitosan fiber for producing functional paper. Two types of wood pulp, such as SwBKP and HwBKP, were mixed with chitosan fiber. Physical and optical properties, water vapor absorption, air permeability, antibacterial activity and ash were measured. And the surface morphology of manufactured paper was observed using SEM. The results are as follows. It was revealed that density, breaking length, burst index, tear index, folding endurance and brightness were reduced but water vapor absorption and air permeability were on the rise in the structural view of SwBKP according to increasing the chitosan fiber ratio. Those HwBKP added chitosan fiber were great not only in the strength but also water vapor absorption and air permeability except for brightness. The water vapor absorption was lower and the air permeability was higher in the HwBKP added various chitosan fiber ratios than those with no chitosan fiber. It is estimated that these properties were related with various mixed rate of chitosan fiber. Particularly, air permeability was strongly dependent on the mixed rate of chitosan fiber. The chitosan fiber has superior antibacterial property, comparing with wood fiber. Adding chitosan fiber to the wood pulp was found to have an excellent antibacterial activity, more than 90%. The ashes were determined within 0.5%. Special bonds between chitosan fiber and wood pulp was observed by SEM and it means that the chitosan fiber were combined equally in the interior of wood pulp. In conclusion, mixing wood pulp with chitosan fiber can not only improves the quality of paper but also extend the usage of paper as a functional paper by using inherent property of chitosan. After all, production of functional paper added chitosan fiber is expected for new valuable industry of paper.

• 한국응용곤충학회지
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• 제50권3호
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• pp.247-251
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• 2011

막대바구미류는 대부분이 목재류를 천공가해하기 때문에 목재문화재에 피해를 주는 경우가 있다. 국내 목재류 문화재에서 발생한 막대바구미류를 정리한 결과, 자작나무막대바구미(Hexarthrum brevicorne Wollaston)가 2004년에 전북 전주시에 위치한 사적 제379호인 전주향교에 소장된 완영책판에 심각한 피해를 주었으며, 2007년에는 경남 밀양소재 박물관에 소장중인 반닫이와 2008년에는 서울 소재 박물관에 관복함, 전남 순천소재 사찰에 보관중인 경판에서도 발생되었고, 분비나무막대바구미(Rhyncolus sculpturatus (Waltl))는 2008년 서울 소재 박물관에서 소장된 목제(재)생활도구를 가해하는 것이 확인되었다. 따라서 소중한 국가자산인 문화재를 해충으로부터 보호하기 위해 보존과학분야에서 종합적인 해충 관리기술이 한층 요구되고 있다.

• Journal of the Korean Wood Science and Technology
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• 제30권3호
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• pp.91-96
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• 2002

This study was carried out to estimate the property of dimensional stability of heat compression of italian poplar wood with low density. Firstly, two levels of pressure conditions were applied using the closed and open-press system. The thermal treatment temperatures were 180℃ and 200℃, respectively. Water absorption tests were conducted in water bath at 25℃ and 100℃ for 35 hours and 1 hour, respectively. The compression rates of wood were 47 percent, 60 percent, and 73 percent, respectively. From these tests, it was found that the dimensional stability of the closed-press system was superior to that of the open-press system. Furthermore, the dimensional stability of compressed wood in the closed-press system was better at 200℃ than 180℃. In compression rate, dimensional stability of 73 percent compression rate was the best result. Considering these results, the best conditions for the dimensional stability of compressed wood were those of the closed-compressing system at high temperatures above 200℃ and larger compression rate. Therefore, it was concluded that the dimensional stability of wood is improved at higher temperature and larger deformation.