• Title/Summary/Keyword: EVA thickness

Search Result 29, Processing Time 0.03 seconds

Experimental study on the effects of EVA(Ethylene Vinyl Acetate) for solar cell's long-term life (EVA(Ethylene Vinyl Acetate) 수지가 태양전지의 장기적인 수명에 미치는 영향에 관한 실험적 연구)

  • Kim, Seon Yong
    • Journal of the Korea Safety Management & Science
    • /
    • v.17 no.4
    • /
    • pp.397-401
    • /
    • 2015
  • In this study, analysed the characteristics of power drop and surface damage in solar cell through high temperature and humidity test in the 3 case of EVA(ethylene vinyl acetate) and 2 case ribbon thickness. The solar cells were tested during the 500hr in $85^{\circ}C$ temperature and 85% relative humidity conditions, that excerpted standard of PV Module(KS C IEC-61215). Through the EL(Electroluminescence) shots, specimen's surface have partialy damaged. Before and after high humidity and high temperature test, ribbon thickness $200{\mu}m$ EVA1 case power drop rate was 8.463%, EVA2 case was 6.667%, EVA3 case was 6.373%. In the ribbon thickness $250{\mu}m$ EVA1 case power drop rate was 6.521%, EVA2 case was 8.517%, EVA3 case was 6.019%. EVA3 case was the lowest power and FF(fill factor) drop rate at the 2 case of ribbon thickness, because EVA3 is laerger than EVA1 and EVA2 in thickness, elongation and tensile strength.

The Electrical Properties of Thin Film Mixed With LLDPE and EVA (LLDPE와 EVA를 혼합한 박막의 전기적 특성)

  • Lee, Jong-Pil;Shin, Hyun-Taek;Cho, Kyung-Soon;Lee, Chung-Ho;Lee, Yoon-Joo;Hong, Jin-Woong
    • Proceedings of the KIEE Conference
    • /
    • 1999.07d
    • /
    • pp.1667-1670
    • /
    • 1999
  • In this paper, We are studied the electrical properties of thin film mixed with LLDPE and EVA, and the specimen is selected as Low Linear Density Polyethylene and Ethylene Vinyl Acetate produced by mixture ratio of 50:50, 60:40, 70:30 and 80:20. (thickness $100[{\mu}m],\;70[{\mu}m],\;50[{\mu}m],\;30[{\mu}m]$). As the electrical properties. one is electrical conduction characteristics of the due to mixture ratio of linear low density polyethylene (LLDPE) and ethylene vinyl acetate(EVA), the other is AC breakdown of specimens due to variation of the thickness. From the result of XRD, it is confirmed that specimen of 80 : 20 and virgin LLDPE have high peaks at $2\theta=21.4[^{\circ}]$ and the peak by the contribution of amorphous at $2{\theta}=19.5[^{\circ}]$ is constant with no relation to mixture ratio, but virgin EVA is somewhat lower.

  • PDF

A Study on the Bond Strength of Coated Rebar by Polymer Cement Slurry Made of EVA and Ultra High-Early Strength Cement (EVA와 초조강시멘트를 사용한 폴리머 시멘트 슬러리 도장철근의 부착강도에 관한 연구)

  • Hyung, Won-gil;Jo, Young-Kug
    • Journal of the Korea Concrete Institute
    • /
    • v.27 no.6
    • /
    • pp.633-640
    • /
    • 2015
  • Polymer cement slurry (PCS) is made from organic polymer dispersion and cement has good adhesion to steel, waterproofness and acid resistance due to being of polymer films formed in cement slurry. The purpose of this study is to evaluate the bond strength of coated rebar by polymer cement slurry made of EVA and ultra high-early strength cement. The test pieces are prepared with EVA polymer dispersion and ultra high-early strength cement having four types of polymer-cement ratios, four types of coating thicknesses and four curing ages, and tested for the bond strength test. From the test results, in general, bond strength of PCS-coated rebar is better than that of uncoated rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day, and coating thicknesses of $75{\mu}m$ and $100{\mu}m$. The maximum bond strength of PCS-coated rebar with ultra high-early strength cement and EVA at polymer-cement ratio of 80%, and coating thickness of $100{\mu}m$ is about 1.32 and 1.38 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness, type of polymer and cement are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can have basic information that PCS-coated rebar with polymer-cement ratio of 80% or 100% and coating thickness of $100{\mu}m$ at curing age of 1-day can replace epoxy-coated rebar.

The study on PV module development using the silicone encapsulation (Encapsulation용 silicone을 사용한 모듈제조 공정에 대한 연구)

  • Jung, In-Sung;Lee, Woo-Jin;Lee, Bum-Su;Yang, O-Bong;Jung, En-Suk;Kim, Chong-Yeal
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.130.1-130.1
    • /
    • 2011
  • Nowadays, the number of PV module corporation is increasing due to demand growth of silicon solar module. However almost study of module is research about increasing of efficiency for it. This study is evaluation and development for process of module using the silicone encapsulation material instead of existing EVA sheet. We are changed adding material ratio on silicone and thickness of silicone. So we get better efficiency than EVA sheet through the evaluation for silicone liquid and modulation. Also, we are test after establishing manufacture system being able to quicker than existing modules line. The result of EVA sheet is average 207.47W and silicone material is 211.32W so we think that silicone is better than EVA sheet.

  • PDF

The Effects of Hardness and Thickness of Midsole on the Bending Properties of Footwear (미드솔의 경도 및 두께가 스포츠화의 굽힘 특선에 미치는 영향)

  • Park, Cha-Cheol
    • Elastomers and Composites
    • /
    • v.41 no.2
    • /
    • pp.125-130
    • /
    • 2006
  • To understand the effect of midsole on the bending stiffness of footwear, bending moment is studied with various hardness and thickness of polyurethane(PU) and poly(ethyl one-co-vinylacetate)(EVA) foams which composed in footwear midsole. The initial bending moment of footwear was appeared at $19^{\circ}$ on bending angle of footwear, and this bending angle was not depend on thickness and hardness of midsole. The bending moments of footwear were also increased with increase of the hardness and thickness of misole which were composed in footwear. Increased hardness and increased thickness of foam and midsole also cause a greater bending moment of the sports shoe, respectively.

The observation of solar cell's micro-crack depending on EVA Sheet's lamination condition for photovoltaic module (PV 모듈용 EVA Sheet의 Lamination 공정 조건에 따른 태양전지 크랙발생 현상 관찰)

  • Kang, Kyung-Chan;Kang, Gi-Hwan;Huh, Chang-Su;Yu, Gwon-Jong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2008.06a
    • /
    • pp.9-9
    • /
    • 2008
  • Recently, the thickness of solar cell gets thinner to reduce the quantity of silicon. And the reduced thickness make it easy to be broken while PV module fabrication process. This phenomenon might make PV module's maximum power and durability down. So, when using thin solar cell for PV module fabrication, it is needed to optimize the material and fabrication condition which is quite different from normal thick solar cell process. Normally, gel-content of EVA sheet should be higher than 80% so PV module has long term durability. But high gel-content characteristic might cause micro-crack on solar cell. In this experiment, we fabricated several specimen by varying curing temperature and time condition. And from the gel-content measurement, we figure the best fabrication condition. Also we examine the crack generation phenomenon during experiment.

  • PDF

Effects of High Performance Greenhouse Films on Growth and Fruit Quality of Tomato (기능성 피복재가 토마토 생육 및 품질에 미치는 영향)

  • Kwon, Joon-Kook;Cho, Myeomg-Whan;Kang, Nam-Jun;Kang, Yun-Im;Park, Kyoung-Sub;Lee, Jae-Han
    • Journal of Bio-Environment Control
    • /
    • v.18 no.3
    • /
    • pp.232-237
    • /
    • 2009
  • This study was performed to investigate the effect of high performance greenhouse films on growth and fruit quality of tomato. For this purpose, polyolefin (PO), fluoric, antidrop, antifog and thermal films were compared to normal film, ethylene vinyl acetate (EVA). In spectral irradiance of the films, UV ($300{\sim}400nm$) transmittance was highest in fluoric film and lowest in PO film. PAR (photosynthetically active radiation, $400{\sim}700nm$) transmittance was higher in fluoric, thermal and PO film, and near infrared ray (NIR, $700{\sim}1,100nm$) transmittance was higher in high performance films, compared to the EVA film. Total light transmittance was higher in order of fluoric, antifog, anti drop, PO, thermal, and EVA film. Day air temperature in greenhouse was highest under fluoric film and lowest under EVA film due to the light transmittance, while night air temperature was highest under PO and anti drop film due to the thickness of film. Tomato fruits grown under the high performance films had 0.2 to $0.5^{\circ}Bx$ higher soluble solids and 15 to 30% higher lycopene content, compared to those grown under the EVA film. The results showed that tomato fruit quality such as soluble solids and lycopene content can be heightened in terms of much irradiation and better light quality of high performance films, compared to the nomal film, EVA film.

The Electrical Properties of Film due to the Mixture Ratio of Linear Lour Density Polyethylene and Ethylene Vinyl Acetate (선형 저밀도 폴리에틸렌과 에틸렌 비닐아세테이트의 혼합비에 따른 박막의 전기적 특성)

  • 이충호;박찬원
    • Journal of the Korean Society of Safety
    • /
    • v.14 no.2
    • /
    • pp.83-89
    • /
    • 1999
  • The electrical properties due to mixture ratio of linear low density polyethylene(LLDPE) and ethylene vinyl acetate(EVA) films are studied. An experimental specimen is selected as LLDPE/EVA of thickness 200${\mu}{\textrm}{m}$ produced by mixture ratio of 50 : 50, 60 : 40, 70 : 30 and 80 : 2 wt%. In temperature range from $25^{\circ}C$ to 12$0^{\circ}C$, the measurement of volume resistivity using a highmegohm meter is performed within 10 minutes since each voltage of DC 100 V, 250 V, 500 V and 1000 V is applied, according to the step voltage method. From FT-IR spectrum for an analysis of physical properties, it can be confirmed that LLDPE blended with EVA shows an absence of carbonyl groups(1735 $cm^{-1}$, C=0) and ether groups(1242 $cm^{-1}$, C-O). The peak of LLDPE and EVA made of mixture ratio of 70 : 30 at 2$\theta$ =21.4$^{\circ}$ in the results of XRD is higher than the others. In the experiment for volume resistivity characteristics in order to investigate the electrical properties of specimen, it is confirmed that volume resistivity is decreased with the increase of the molecular motion and temperature.

  • PDF

Polarity-tuned Gel Polymer Electrolyte Coating of High-voltage LiCoO2 Cathode Materials

  • Park, Jang-Hoon;Cho, Ju-Hyun;Kim, Jong-Su;Shim, Eun-Gi;Lee, Yun-Sung;Lee, Sang-Young
    • Journal of the Korean Electrochemical Society
    • /
    • v.14 no.2
    • /
    • pp.117-124
    • /
    • 2011
  • We demonstrate a new surface modification of high-voltage lithium cobalt oxide ($LiCoO_2$) cathode active materials for lithium-ion batteries. This approach is based on exploitation of a polarity-tuned gel polymer electrolyte (GPE) coating. Herein, two contrast polymers having different polarity are chosen: polyimide (PI) synthesized from thermally curing 4-component (pyromellitic dianhydride/biphenyl dianhydride/phenylenediamine/oxydianiline) polyamic acid (as a polar GPE) and ethylene-vinyl acetate copolymer (EVA) containing 12 wt% vinyl acetate repeating unit (as a less polar GPE). The strong affinity of polyamic acid for $LiCoO_2$ allows the resulting PI coating layer to present a highly-continuous surface film of nanometer thickness. On the other hand, the less polar EVA coating layer is poorly deposited onto the $LiCoO_2$, resulting in a locally agglomerated morphology with relatively high thickness. Based on the characterization of GPE coating layers, their structural difference on the electrochemical performance and thermal stability of high-voltage (herein, 4.4 V) $LiCoO_2$ is thoroughly investigated. In comparison to the EVA coating layer, the PI coating layer is effective in preventing the direct exposure of $LiCoO_2$ to liquid electrolyte, which thus plays a viable role in improving the high-voltage cell performance and mitigating the interfacial exothermic reaction between the charged $LiCoO_2$ and liquid electrolytes.

The Effects of Curing Age and Thickness of Coating Material on the Bond Strength of PCS-Coated Rebar to Cement Concrete (도장재의 양생재령과 도장두께가 PCS 도장철근과 시멘트 콘크리트와의 부착강도에 미치는 영향)

  • Jo, Young-Kug
    • Journal of the Korea Institute of Building Construction
    • /
    • v.17 no.4
    • /
    • pp.331-339
    • /
    • 2017
  • The purpose of this study is to evaluate the effect of curing age and thickness of coating material on the bond strength of polymer cement slurry(PCS)-coated rebar that can replace epoxy-coated rebar. The test specimens were prepared with two types of cement, two types of polymer dispersion as St/BA and EVA, two polymer-cement ratios, two coating thicknesses and three curing ages, and tested for bond strength test to cement concrete. The flexural behavior of RC beam that is made by optimum conditions such as polymer-cement ratio of 80%, coating thickness of $100{\mu}m$ and curing age of 7 days of PCS recommended from the bond strength test is also conducted. From the test results, The maximum bond strength of PCS-coated rebar at curing age of 7-day and coating thickness of $100{\mu}m$ was about 1.52 and 1.58 times respectively, the strength of plain and epoxy-coated rebar. The ultimate loads of RC beam using PCS-coated rebar were range of 81.1% to 102.3% of that of plain rebar, and 98.4% to 124.1% of that of epoxy-coated rebar. It is apparent that PCS-coated rebar with EVA, curing age at 7-day and $100{\mu}m$ can replace epoxy-coated rebar in construction field.