• 한국재료학회지
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• 제21권5호
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• pp.255-262
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• 2011

This paper has relatively high technical standard and experimental skill. The fabrication of TCO film with high transparency, low resistance and low chromaticity require exact control of several competing factors. This paper has resolved these problems reasonably well, thus recommended for publication. Indium tin oxide(ITO) thin films were by D.C. magnetron roll-to-roll sputter system utilizing ITO and $SiO_2$ targets of ITO and $SiO_2$. In this experiment, the effect of D.C. power, winding speed, and oxygen flow rate on electrical and optical properties of ITO thin films were investigated from the view point of sheet resistance, transmittance, and chromaticity($b^*$). The deposition of $SiO_2$ was performed with RF power of 400W, Ar gas of 50 sccm and the deposition of ITO, DC power of 600W, Ar gas of 50 sccm, $O^2$ gas of 0.2 sccm, and winding speed of 0.56m/min. High quality ITO thin films without $SiO_2$ layer had chromaticity of 2.87, sheet resistivity of 400 ohm/square, and transmittance of 88% and $SiO_2$-doped ITO Thin film with chromaticity of 2.01, sheet resistivity of 709 ohm/square, and transmittance of more than 90% were obtained. As a result, $SiO_2$ was coated on PET before deposition of ITO, their chromaticity($b^*$) and transmittance were better than previous results of ITO films. These results show that coating of $SiO_2$ induced arising chromaticity($b^*$) and transmittance. If the thickness of $SiO_2$ is controlled, sheet resistance value of ITO film will be expected to be better for touch screen. A four point probe and spectrophotometer are used to investigate the properties of ITO thin films.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.69.2-69.2
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• 2010

Recently, bulk hetero-junction cells have been extensively studied by many researchers. Most of these cells were fabricated by spin coater. However, the spin coating process is not favorable to the large-scaled industry because it is not compatible with roll-to-roll process. One of the alternative methods is Doctor blading. In this study, we fabricated large OPV cells having total area of $100cm^2$. The buffer layer was Poly-(3,4-ethylenedioxythiophene) : poly-(styrenesulfonate) aqueous dispersion (PEDOT:PSS) and the active material is poly (3-hexythiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blend in the solvent of Chlorobenzene. All of the organic layers were coated by dragging the blade with a speed of 5~20 mm/s on the stage with a temperature of $50^{\circ}C$. As-bladed PEDOT:PSS layer was baked at $120^{\circ}C$ for 10 minutes to eliminate the water. The cell structure is patterned ITO substrate/PEDOT:PSS/P3HT:PCBM/LiF/Al. The topmost electrode, LiF/Al, was deposited by thermal evaporation. After depositing electrode, and the cell was annealed at $150^{\circ}C$ for 30 minutes. The measured ISC, VOC, fill factor, and PCE were 2.95 A, 5.86 V, 0.32, and 0.78%, respectively. PCE was quite low but the large active area could be obtained successfully.

• 펄프종이기술
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• 제32권2호
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• pp.26-34
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• 2000

Understanding the nip geometry and heat transfer phenomena of soft nip calenders, which has been used in the production of newsprint and coated papers for many years, is very important since improper setting of soft nip calendering conditions causes deterioration of paper quality and productivity. In this study theoretical analysis on nip pressure and heat transfer phenomena in the nip of soft nip calenders has been made. The variables examined were calendering pressure, surface temperature of the heating roll, nip residence time and ingoing sheet moisture, By measuring nip widths and maximum nip pressure with Prescale film at a normal temperature, accurate line load has been obtained. With this line load, nip pressures at different temperature and nip widths were calculated. Results showed that as temperature increased, nip widths increased and nip pressures decreased. Equations derived for the heat conduction phenomena in soft nip calender nip were derived based on the semi-infinite plate and finite difference method and were used for the analysis of heat transfer within the nip. Temperature profiles in z-direction of paper within the nip were obtained. Finite difference method allowed more accurate analysis of the heat transfer in the calender nip. In this study newsprint and coated paper were considered as a single plate and two-layer plate consisted of sheet and coating layers, respectively. Heat trans-fer to paper increased as heated roll surface temperature and nip residence time were increased.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.282-285
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• 2009

Nanostructured OLED light extraction films have been made via roll-to-roll coating processes. Their on-axis and integrated outcoupling efficiencies reach 2X and 1.3-1.8X, respectively. Optical performance and effects of the nanostructured film on pixel blur and image ghosting will be discussed.

• 대한전자공학회논문지SD
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• 제48권6호
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• pp.7-14
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• 2011

본 논문은 PDMS(polydimethyl siloxane) 스탬프를 이용한 원통형 마이크로 접촉인쇄(roll-type micro-contact printing)에 관한 것으로 대면적 플라스틱 기판에 미세 금속 전극 인쇄를 PDMS 스탬프의 평탄화, 은 나노 잉크의 은 함량, 공정변수인 코팅속도, 잉킹속도, 프린팅속도, 프린팅 압력을 조절하여 가장 우수한 인쇄특성을 나타내는 조건을 도출하였다. 그 결과 면적 $4.5cm\;{\times}\;4.5cm$ 기판에 최소선폭 10 um, 두께 300 nm, 표면거칠기 40 nm 이하, 비저항 $2.08\;{\times}\;10^{-5}{\Omega}{\cdot}cm$의 특성을 갖는 은미세 전극을 인쇄하였다.

• 대한기계학회논문집A
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• 제35권8호
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• pp.869-876
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• 2011

동적 특성에 영향을 받는 롤 코팅의 평형적인 두께 예측과 불안정성을 분석함은 중요하다. 본 연구에서는 강체/변형롤 사이에서 생성되는 마이크로 코팅액의 두께를 예측하기에 앞서 압착되어 회전하는 두 롤 사이에 발생하는 접촉 압력의 분포와 변형롤의 변형 형상을 예측하고자 한다. 또한 변형롤의 재료상수와 롤의 속도 및 마찰계수 그리고 압착 크기 등의 변수들에 대한 접촉압력분포를 수치적인 방법으로 측정하여 유효한 변수들의 영향을 분석하고자 한다. 수치해석 방법으로는 유한요소법을 사용하였고 두 롤을 모델링하여 변형롤에 고무물성치를 초탄성체 모델로 가정하여 일반적으로 사용되는 Mooney Rivlin 계수를 사용하였고 40~80rpm 사이의 속도로 회전할 때 접촉 형상 및 압력분포를 분석하였다. 접촉형상의 경우 압착정도에 따라 변하고 그외 변수들에는 영향을 받지 않고 접촉압력의 경우 변형롤의 물성치와 압착정도에 의해 주요한 영향을 받고 속도 및 마찰계수에는 영향을 받지 않음을 알 수 있다.

• 한국지반환경공학회 논문집
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• 제23권1호
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• pp.31-37
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• 2022

본 연구는 기존 PVC코팅망의 성능 부족으로 인한 찢어짐으로 인근 피해 확대를 방지하기 위하여 고강도 선재 포획망을 제작하여 이를 방지하기 위한 기술을 개발하기 위해 시험을 진행한 것이다. 시험 방법은 국제 기준인 ISO 17746:2016을 참조하여 steel wire ring panel과 steel wire rope net panel, roll에 대한 장력시험(인장시험)에 대한 사항의 규정을 따라, 고강도 선재 포획망의 장력시험 시 고강도 선재 포획망 시편은 폭 1,000mm 이상, 최소 시편크기 1.0m²를 제작하였다. 시험결과의 하중-변위 곡선을 비교하여 기존의 PVC 코팅망 보다 성능이 얼마나 향상되었는지를 분석하였다.

• 한국산학기술학회논문지
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• 제13권9호
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• pp.3822-3826
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• 2012

소형 UV 챔버 내부온도 및 챔버 내 체류시간이 Urethane Acrylate 의 경화속도에 미치는 영향을 조사하였다. UV 램프에 가해지는 Power를 60, 80, 100% 로 조절하여 UV 조사량 (UV dose)를 변경하였고 필름이 지나가는 챔버 내부의 가이드롤 (또는 패턴롤)에 냉각수를 투입하여 롤 자체의 온도에 변화를 주었다. 또한 코팅속도를 조절하여 챔버 내부에서의 체류 시간을 변경시켰는데 이들 조건들이 Urethane Acrylate 의 경화에 어떠한 영향을 미치는지를 알아보기 위하여 경화된 필름의 gel 분율을 측정, 비교하였다. 본 연구를 통해 Power가 증가 할수록 경화기 내부의 온도는 상승 하였으며 냉각수 투입에 따라 경화기 내부의 온도는 감소하였는데 이러한 경화기 내부의 온도변화는 UV 경화에 큰 영향을 미치지 않음을 알 수 있었다. 반면에 코팅속도가 증가할수록 경화필름의 gel 분율은 감소하였는데 이는 충분한 경화를 위해서는 경화기내부에서의 체류시간이 일정 이상이 되어야 함을 의미하였다. 한편, 체류시간에 따른 UV dose 측정 및 UV 램프주변의 열유동 해석을 통하여 램프주변의 온도분포 해석을 시도하였는데 이러한 결과들을 바탕으로 UV 경화기 구조 및 운전 조건이 UV 경화된 제품의 특성에 어떠한 영향을 미치는지 알 수 있었다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.95-95
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• 2009

Zinc coatings provide the most effective and economical way of protecting steel against corrosion. There are three types of galvanizing lines typically used in production line in galvanizing industries,Galvanize (GI) coating (Zn-0.1-0.3%Al), Galfan coating (Zn-5%Al), Galvalume(GL) coating (45%Zn-Al). In continuous Galvanizing lines, the immersed bath hardware (e.g. bearings, sink, stabilizer, and corrector rolls, and also support roll arms and snout tip) are subjected to corrosion and wear failure. Understanding the reaction of these materials with the molten Zn alloy is becomes scientific and commercial interest. To investigate the reaction with molten Zn alloys, static immersion test performed for 4, 8, 16, and 24 Hr. Two different baths used for the static immersion, which are molten Zn and molten Zn-55%Al. Microstructures characterization of each of the materials and intermetallic layer formed in the reaction zone was performed using optical microscope, SEM and EDS. The thickness of the reaction layer is examined using image analysis to determine the kinetics of the reaction. The phase dominated by two distinct phase which are eutectic carbide and matrix. The morphology of the intermetallic phase formed by molten Zn is discrete phase showing high dissolution of the material, and the intermetallic phase formed by Zn-55wt%Al is continuous. Aluminum reacts readily with the materials compare to Zinc, forming iron aluminide intermetallic layer ($Fe_2Al_5$) at the interface and leaving zinc behind.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.53.5-53
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• 2001

In continuous galvanizing process at steel making plant, coating weight on the surface of strip that pass through air knife is controlled by the pressure at the chamber of air knife and the gap between the nozzle of air knife and strip. The pressure can be easily measured and controlled. But it is difficult to measure the distance between Air knife nozzle and strip, and also difficult to decide how much distance air knife move. Because, the gap between nozzle and strip varies with the height of air knife, intermesh of stabilizing roll and welding of strips that have different thickness. In this research, we developed a gap sensor that can measure the relative distance between Air knife nozzle and strip. And several tests are performed to find optimal condition for application at real plant. We performed test in which the possibility of the sensor to apply ...