• 한국화재소방학회논문지
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• 제25권3호
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• pp.107-112
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• 2011

본 연구에서는 대전방지필름 제조공장에서의 화재위험성 등을 고찰하였다. 대전방지필름 제조공정에서는 에탄올, 메탄올, 이소프로필알콜 같은 인화점이 낮은 용제가 사용되며 이들 용제의 최소점화에너지는 0.16 mJ~0.65 mJ로 낮은 방전에너지에도 쉽게 착화할 위험성이 있다. 제조공정 각 부분에서 발생하는 정전기 전위를 측정한 결과, 합지 과정의 필름에서 17kV~20kV의 전위가 측정되었다. 이는 화재 폭발 방지를 위한 부도체의 대전 목표 값인 5kV를 초과하는 것이다. 따라서 대전방지필름 제조공장에서 정전기 방전에 의한 화재위험성이 높다는 것을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제20권2호
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• pp.31-42
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• 1992

In this study, the relative effectiveness of antimony trioxide-containing coat on fire retardancy of plywood, particleboard and medium density fiberboard was investigated and compared through ISO ignition test and inclined panel test with non-coated ones. The results obtained were summarized as fallows: Any treated materials was not ignited in inclined panel test with 5 minutes, but only particleboard among treated ones burned in ISO ignition test with fairly delayed time. The weight loss rate of plywood decreased with the increased addition level of fire-retardant and the least values were obtained in particleboard and MDF at addition level of 7% and 5% respectively. Carbonized area of wood based materials decreased with the increased addition level of fire retardant. The temperatures of back in plywood, particleboard treated with fire-retard ant coat containing 7% $Sb_2O_3$ showed the lowest but MDF did not show any effectiveness with the increased addition level. The first flash time of plywood treated with fire retardant coat containing 9% $Sb_2O_3$, MDF and particleboard treated with fire retardant coat containing 7% $Sb_2O_3$ were 257sec., 286.4sec., 165.4sec. respectively.

• 한국표면공학회지
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• 제50권6호
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• pp.460-464
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• 2017

As increasing thermal efficiency of the gas turbine, the performance improvement of thermal barrier coatings is also becoming important. Ytrria stabilized zirconia(YSZ) is the most popular materials for ceramic top coating because of its low thermal conductivity. In order to enhance the performance of thermal barrier coatings for hot sections in the gas turbine, suspension plasma spraying was developed in order to feed nano-sized powders. YSZ coatings formed by suspension plasma spraying showed better performance than YSZ coatings due to its exclusive microstructure. In this research, two YSZ coatings were deposited by suspension vacuum plasma spraying at 400 mbar and 250 mbar. Microstructures of YSZ coatings were analyzed by scanning electron image(SEM) on each spraying conditions, respectively. Crystalline structure transformation was not detected by X-ray diffraction. Thermal conductivity of suspension vacuum plasma sprayed YSZ coatings were measured by laser flash analysis. Thermal conductivity of suspension vacuum plasma sprayed YSZ coatings containing horizontally oriented nano-sized pores and vertical cracks showed $0.6-1.0W/m{\cdot}K$, similar to thermal conductivity of YSZ coatings formed by atmospheric plasma spraying.

• 한국재료학회지
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• 제29권11호
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• pp.657-663
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• 2019

In this work, we study physical and mechanical properties of oxide films formed on AZ91D magnesium alloy by plasma anodization at different temperatures. It is found that the higher the electrolyte temperature, the lower is the breakdown voltage of oxide layer. This is probably because films formed at higher temperatures are thinner and denser. Moreover, electrolyte temperature plays an important role in the physical properties of the films. As the electrolyte temperature increases from 20 to $50^{\circ}C$, the hardness of the oxide layer increases. Friction test against steel balls indicates that wear scars become narrower for films formed at higher temperatures because the films are harder, as indicated by the Vickers hardness. The thinner and denser nature of the oxide film formed at $50^{\circ}C$ is also advantageous for heat transfer when film is used as a heat sink. Laser flash test results show very fast heat transfer for AZ91D with plasma anodized oxide layer formed at higher temperatures.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제44차 학술발표회
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• pp.61-61
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• 2011

지구 온난화로 인해 환경파괴, 병원성 세균 감염 등에 의한 각종 질병과 아토피 피부염 등 수없이 많은 요소들에서 우리 몸을 보호하기 위하여 친환경 소재의 용품들이 각광 받고 있다. 이중에서도 키토산과 칼슘알지네이트는 천연재료로써 이미 다른 분야에서 응용되어 사용되고 있으며, 이 두 가지 천연재료를 두 층으로 면섬유에 코팅시킨 CCAC섬유를 제조하였다. CCAC섬유와 키토산이 코팅된 면섬유, 칼슘알지네이트가 코팅된 면섬유, 미처리 면섬유의 총 4가지 섬유에 체액, 증류수, 생리식염수의 각각의 조건에서 흡습량, 흡습시간을 측정하여 비교하고, 수분율과 함수율을 측정하고, 접촉각을 Contact angle system OCA20을 이용하여 측정하였다. CCAC섬유의 키토산 부착 함량을 알아보기 위하여 정량적인 방법으로 add-on율을 이용하여 확인하고, 정성적인 방법으로 원소분석기(Elemental Analyzer, FLASH 1112)를 이용하여 측정하였다. 칼슘알지네이트의 함량 분석은 EDS(EX-250, HORIBA, Japan)를 이용하여 측정하고, 직물의 표면과 단면의 형태는 주사전자현미경(S-4100, Hitachi Co., Japan)으로 ${\times}100$, ${\times}1000$ 배율로 측정하여 단면과 표면 상태를 확인하고, 물리적인 특성은 KES-FB system 을 통하여 확인 하였다.