• Journal of the Korean Wood Science and Technology
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• 제38권3호
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• pp.185-190
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• 2010

중밀도섬유판(MDF)에 글씨나 그림을 새김질한 목판을 제조하고, 이를 탄화하여 서각작품을 제작하는 방법을 개발하였다. 섬유판의 탄화에 따른 외형적 및 조직학적 변화를 검토하고 제작된 탄화보드 서각작품에 대한 미학적 특징을 고찰하였다. 서각한 MDF를 $850^{\circ}C$에서 탄화한 결과, 할열이나 뒤틀림은 관찰되지 않았으며, 치수는 가로 21.8%, 세로 18.8%, 두께 43.5% 줄어들었고, 중량은 69.2%, 밀도는 14.8% 감소하였다. 탄화보드의 전자 현미경에 의한 관찰 결과, 당초 섬유의 표면과 벽공을 둘러싸고 있던 접착제가 탄화되면서 목질섬유의 표면이 매끄럽게 변하고 벽공이 개열되며 섬유의 크기가 균일화되고 조직이 치밀화되는 현상을 나타내었다. 수작업에 의한 서각기법과 무할열 탄화기법의 융합에 의해 새로운 탄화보드 서각작품의 제작이 가능하였다. 탄화보드 서 각작품은 목탄의 기능성과 서각의 아름다움을 부여하는 새로운 친환경 예술영역의 한 분야로서 이용될 수 있을 것이다.

• Journal of the Korean Wood Science and Technology
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• 제44권4호
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• pp.505-514
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• 2016

To study mechanical properties of fiberglass reinforced wood-based composite (FRWC), fiberglass with a diameter of $20{\mu}m$ was selected to prepare test specimens. Mechanical properties of fiberglass reinforced wood-based composite were determined by three-point-bending test while its microstructure was characterizes by scanning electron microscopy (SEM). The results showed that mechanical properties of fiberglass reinforced wood-based composite were superior to that of the wood fiberboard based on the contrasting mechanical curves and the analysis of fracture mechanism. It is believed that the material design with this "sandwich" structure brings a unique buffering capacity of fiberglass into play in the composites. So the specimen did not produce a sudden fracture failure at high level of applied loads because it had a bearing ability. The SEM analysis showed that the working strength of PVAc adhesive was high; under a bearing force, it could properly transfer a load. In addition, glass fiber mesh and wood fiber board combined well.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.32-40
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• 2020

While the utilization of wood as a raw material in related industries has been increasing with the population increasing, the availability of wood from natural forests has continued to decline. An alternative to this situation is the manufacture of particleboard from non-wood lignocellulose materials through the modification of sandwich particleboard (SPb) using bamboo strands as reinforcement. In this study, strandsof belangke bamboo (Gigantochloa pruriens W) and tali bamboo (Gigantochloa apus) were utilized. The non-wood particles included sugar palm fibers, cornstalk, and sugarcane bagasse. The board was made in a three-layer composition of the face, back, and core in a ratio of 1: 2: 1. The binder used was 8% isocyanate resin. The sheet was pressed at a temperature of 160℃ for 5 min under a pressure of 3.0 N/㎟. Testing included physical and mechanical properties based on the JIS A 5908 (2003) standard, while acoustic testing was based on ISO 11654 (1997) standards. The results showed that using bamboo strands as reinforcement has an effect on the mechanical and physical properties of SPb. Almost all the types of boards met the JIS A 5908 (2003) standards, with the exception of thickness swelling (TS) and internal bond (IB) parameters. Based on the thickness swelling parameter, the C-type board exhibited the best properties. Overall, the B-type board thatused a belangke bamboo strand for the surface and sugarcane bagasse as the core underwent the best treatment. Based on the acoustical parameter, boards using a tali bamboo strand for the surface and sugar palm fiber as the core (E-type board) exhibited good sound absorption properties.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.721-724
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• 2008

국내 초고층 프로젝트의 증가에 따라 필연적으로 고강도 콘크리트의 사용이 증가되고 있다. 콘크리트의 강도가 증가됨에 따라 화재시 단면결손을 유발하는 폭렬의 경향성이 커지고, 콘크리트부재 내부의 온도를 현저하게 증가시키며 심각한 구조적 손상을 유발할 수 있다는 문제점이 대두되었고, 정부에서도 2008년 7월부터 고강도 콘크리트의 내화성능 관리기준을 시행하고 있다. 이에 국내 각 건설사들은 50MPa 이상의 고강도 콘크리트에 대하여 폭렬방지 대책을 수립 중에 있다. 본 연구소에서는 신축공사 및 리모델링공사에도 적용이 가능한 고강도 콘크리트 폭렬방지 공법인 PFB (Posco E&C Fire Board) 공법을 개발하여 지속적인 공법 개선에 노력하고 있다. 본 연구는 고강도 콘크리트 폭렬방지 대책으로 개발한 PFB 공법을 기존의 습식공법에서 현장적용성 및 경제성이 우수한 건식화 공법개발을 위한 기초 연구로 PF보드의 기초물성 평가, 3시간 내화시험 및 현장 적용위한 실시 상세 설계를 실시하여 당사 초고층 현장에 적용하기 위한 기본 자료로 활용 하고자 하였다.

• 패션비즈니스
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• 제27권2호
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• pp.39-51
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• 2023

The purpose of this study was to effectively improve the thigh muscles of adult women working from home due to COVID-19. In this study, ten adult women working from home performed 1) an electromyography test, 2) a static balance test on a balance board, and a 3) dynamic balance test by squatting on a Bosu ball four times: before electric muscle stimulation (EMS), after EMS, after high-intensity circuit training (HICT), and after EMS plus HICT. For this test, EMS was attached to a medical knee support to manufacture an EMS knee band that could be easily worn regardless of the location. For the experiment, EMS(electric muscle stimulation) was attached to the medical knee protector to manufacture an EMS knee band that can be easily worn regardless of location, and was measured based on the right foot. The study results confirmed that in all tests (electromyography test, static balance test on the balance board, and dynamic balance test by squatting on a Bosu ball), thigh strength improved in the order of treatment before EMS, after EMS, after HICT, and after EMS plus HICT. The study showed that people working from home or with activity restrictions due to COVID-19 had better exercise effects when wearing the EMS knee band and performing HICT, even in a small space.

• Journal of the Korean Wood Science and Technology
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• 제27권4호
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• pp.57-64
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• 1999

This research was carried out to investigate the effects of density, resin and particle types on the physical and mechanical properties of the composites made from various wood particles mixed with coating paper. The experiment was designed to apply with three particles (flake, chip, and fiber) and three resin types (urea, phenol and PMDI resin). The mixed ratio of coating paper to wood particle was fixed on 50 to 50% in each board making. And also it was designed to apply for four density levels (0.6, 0.7, 0.8 and 0.9 g/$cm^3$) and four mixed formulations of coating paper to wood particle (10:90, 20:80, 30:70, and 40:60 %) to analyze clearly the effects of PMDI resin. Coating paper-wood particle composites have acceptable bending strength (MOR, MOE) though the mixed ratio of coating paper was increased, but have low internal bond strength and poor dimensional stability (WA, TS, LE). Composites with high density had higher mechanical properties but showed lower physical properties than composites with low density. In conclusion, at least up to 20% mixed ratios, coating paper-wood particle composites have acceptable physical and mechanical properties, and PMDI resin has possibility for coating paper-wood particle composite manufacture.

• 펄프종이기술
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• 제39권5호
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• pp.52-57
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• 2007

Corrugated fiberboard is a representative packaging material because of high compressive strength and stiffness in spite of light weight. The flutes of corrugated fiberboard are various depending on the height and the number per unit length of flute. The corrugated fiberboard with microflute like E, F or G with low height less than 1.5 mm has developed. Because it has some advantages including higher stiffness and lower requirement of fiber than carton board, it has a possibility to replace folding box board. Its consumption has been increased with the various applications like graphic packaging. As microflute has the different geometry from other conventional flutes, it can show the different behavior in testing and it may require a new testing method. In this study, we evaluated the edgewise compressive strength of the corrugated fiberboard with microflute according to ISO and other standard test methods. And the effect of specimen shape and platen compression rate was examined. From this study, we found that ISO methods was suitable and reasonable methods for corrugated fiberboard with microflute.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.228-229
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• 2018

In the construction industry, we have set goals such as reduction of greenhouse gas emissions and reduction of energy use. In particular, reduction of CO₂ emissions in the concrete manufacturing process, reduction of industrial waste and industrial wastes into concrete The zero-emission level of reuse as a resource is under review. On the other hand, the cost of stone is expensive due to small quantity production of domestic stone production in order, it is difficult to carry and construct with heavy material, and it takes long time to construct. In order to solve the shortage of supply and demand of natural stone, various kinds of stone powder, artificial stone made by putting stone texture on the surface of mortar or concrete, fiber reinforced plate, tiles and the like are increasingly used. In this study, the artificial stone using slag and recycled aggregate instead of natural stone was fabricated and the strength characteristics were evaluated for its applicability and feasibility.

• 한국농촌건축학회논문집
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• 제23권4호
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• pp.63-71
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• 2021

The purpose of this study was to investigate whether the standard models for rural housing and wooden housing model have performance for hygrothermal and to propose a way of improvement relevant to hygrothermal performance for those models. All of the models to be analyzed were found to have some parts that were absent of stability in terms of performance for hygrothermal. In the process of analyzing the causes and proposing improvement measures, the following conclusions were derived. Fist, The exterior surface of the structure should be composed of a structure with good moisture permeability, and for the interior surface, a variable vapor retarder paper should be applied in consideration of the reverse condensation phenomenon in summer. Second, in terms of performance for hygrothermal, applications of external insulation plaster finish to the exterior wall or of ventilation method using a rafter vent on the roof should be avoided. Third, a rain screen method with a ventilation layer should be applied to the exterior wall, and a method of constructing ventilation layer separated from the insulation layer with a vapor retarder paper should be applied to the roof. Fourth, the application of insulation materials having capillary action, such as wood fiber insulation board or cellulose insulation board, contributes to more stable performance for hygrothermal.

• 한국음향학회지
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• 제28권8호
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• pp.781-789
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• 2009

다목적홀의 음향을 1:50 축소모형으로 예측 및 평가하기 위해 필요한 모형재료의 구성과 흡음특성에 대해 연구하였다. 실제 홀에서의 반사면 및 가변음항요소, 객석의 설계요소별 흡음특성 (125Hz-lkHz 평균)을 기준으로 축소모형의 형상과 재질을 선정하였으며, 흡음율은 상사의 법칙과 ISO 354를 준용하여 측정하였다. 그 결과, 주벽체의 평균흡음율은 0.08로 래커 코팅된 MDF나 아크릴이 적합하며, 객석 의자, 관객 및 연주자 평균흡음율은 각각 0.64, 0.74와 0.45를 목표로 할때 목재, 흡음천과 폼보드를 조합하여 흡음률을 재현하였다. 흡음커튼과 배너는 적용부위 및 단면설계에 따라 흡음재의 마운팅 방법을 선택하였으며, 배면공기층이 없는 상태 (A형 마운팅)에서의 평균흡음율이 0.42, 0.9 m 배면공기층 조건에서 시료 양단이 고정된 상태 (E형 마운팅)에서는 0.47, 천장에 매단 상태 (G형 마운팅)에서는 0.45로 나타났다. 특히, 배면공기층의 증가에 의해 저주파 대역 흡음력이 증가하였다. 스테이지 하우스 내부는 평균흡음율 0.68의 Fiber glass board 시공을 예상하여 흡음재와 스피커망 원단을 조합하여 재현하였다. 본 연구에서 도출된 모형 재료의 형상과 흡음특성은 향후 1:50 축소모형으로 다목적홀의 형상에 의한 중주파 대역 이하의 음향예측에 유용하게 활용될 것으로 사료된다.