• 한국포장학회지
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• 제27권1호
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• pp.1-8
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• 2021

본 연구는 기능성 항균 포장재를 신선식품에 적용하기 위한 연구로서 Zeolite/Zinc-polypeptide를 식품용 포장재 중 하나인 PP 필름에 코팅하여 항균 및 항진균성을 확인하였다. 이를 검증하기 위하여 Zeolite/Zinc-polypeptide를 PP 필름에 각각 5%, 10%, 15% 농도로 코팅하였으며, FESEM과 FT-IR 분석을 통해 분산된 Zeolite/Zinc-polypeptide의 코팅 여부를 확인하였다. 또한 항균 효과를 검증하기 위하여 대조군과 코팅 물질의 농도에 따른 필름의 항균 및 항진균성을 분석하였다. 코팅 필름의 표면 분석 결과 PP 필름의 표면에서 Zeolite/Zinc-polypeptide의 농도에 따라 코팅 액의 분포 크기가 불규칙하지만 넓게 나타났다. 또한 항균 효과에 따른 분석 결과 박테리아 균 중 하나인 E. coli에서 99.9%의 항균 효과를 확인하였으며, R. oryzae의 성장을 약 70% 억제하여 PP 필름 코팅 적용 후에도 Zeolite/Zinc-polypeptide가 E. coli와 R. oryzae에 대하여 항균 및 항진균 특성을 갖고 있음을 확인하였다. 이에 따라 Zeolite/Zinc-polypeptide 코팅 필름은 기능성 포장재로서 신선식품의 부패 방지와 보관수명 향상에 효과적일 것으로 보이며, 향후 다양한 신선식품에 적용하기 위한 저장 실험이 요구되어진다.

• Corrosion Science and Technology
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• 제16권1호
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• pp.38-47
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• 2017

Due to various types of Zn coatings for many decades for various applications, it is imperative to study and compare their corrosion resistance properties of some of these. Here, we introduce a systematic methodology for evaluation and validation of corrosion protection properties of metallic coatings. According to this methodology, samples are were exposed in an advanced cyclic corrosion test chamber according to ISO 14993, and removed at the end of each withdrawal for respective corrosion and electrochemical characterization to evaluate both barrier and galvanic protection properties. Corrosion protection properties of coatings were evaluated by visual examination according to ISO 10289, mass loss and subsequent corrosion rate measurements, electrochemical properties, and advanced electrochemical scanning techniques. In this study, corrosion protection properties of a commercial zinc rich coating (ZRC) on AISI 1020 mild steel substrates were evaluated and benchmarked against hot dip galvanized (HDG). Results were correlated, and corrosion protection capabilities of the two coatings were compared. The zinc rich coating performed better than hot dip galvanized coating in terms of overall corrosion protection properties, according to the exposure and experimental conditions used in this study. It proved to be a suitable candidate to replace hot dip galvanized coatings for desired applications.

• Corrosion Science and Technology
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• 제11권1호
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• pp.15-19
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• 2012

Both electrogalvanized and hot-dip galvanized steel sheets have been finally produced via organic-inorganic surface coating process on the zinc surface to enhance corrosion resistance and afford additional functional properties. Recently, POSCO has been developed a variety of chromate-free coated steels that are widely used in household, construction and automotive applications. New organic-inorganic hybrid coating solutions as chromate alternatives are comprised of surface modified silicate with silane coupling agent and inorganic corrosion inhibitors as an aqueous formulation. In this paper we have prepared new type of hybrid coatings and evaluated quality performances such as corrosion resistance, spot weldability, thermal tolerance, and paint adhesion property etc. The electrogalvanized steels with these coating solutions exhibit good anti-corrosion property compared to those of chromate coated steels. Detailed components composition of coating solutions and experimental results suggest that strong binding between organic-inorganic hybrid coating layer and zinc surface plays a key role in the advanced quality performances.

• 한국표면공학회지
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• 제30권5호
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• pp.320-332
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• 1997

The development of colored surface on zinc coating by the oxidation of a melten alloy of zinc with a minor amount of oxygen-avid additive such as tianium has been studied. Using a galvanizing Zinc alloy containing 0.1 to 0.3wt%Ti, gold, purple or blue color was developed clearly and stably, depending upon the extent of oxidation, by air cooling after hot dipping in a bath at temperature of $550^{\circ}C$ to $600^{\circ}C$. The source of the color is light interference with surface oxide layer. THe final color depends on the thickness of the color depends on the thickness of $TiO_2$, played So compositing, temperature and time at elevated temperature after are all controlling variables. Since oxidation film such as $TiO_2$ played role of passivation film, the corrosion resistance in a colored galvanized steel sheet. It is also thought that surface oxide layer of $TiO_2$ inhibited dissolution of the coating layer.

• 한국표면공학회지
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• 제32권2호
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• pp.157-164
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• 1999

In this study the effect of nickel addition on the coating weight of mini-mill steels containing silicon has been studied. It is shown that the pure zinc accelerated growth of the alloy layers occurred by a rapid growth of the zeta phase at 0.06%Si. The addition of 0.06%Ni to a pure zinc bath was found to be very effective in reducing the coating weight and promoting preferential development of the delta phase. The coating obtained by immersion in the Zn-Ni bath shows the presence of a nickel-rich region between the zeta phase and the eta phase. It is suggested that nickel prevents the rapid growth of the zeta phase due to the formation of the Zn-Ni-Fe ternary compound, which may act as a barrier to inward diffusion of zinc or iron at the zeta-eta boundary.

• 한국표면공학회지
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• 제28권5호
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• pp.300-308
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• 1995

The effect of nitrogen finishing for the control of coating weight in a nitrogen sealing box on the coating surface property in hot dip galvanizing process has been studied. The coated surface is free of oxide marks and edge overcoated. The coating uniformity is excellent ; the standard deviation of the coating thickness along width of the specimen was $1~1.2\mu\textrm{m}$ in the box whereas $2.5~3\mu\textrm{m}$ in the air. Considering surface quality of the coating such as oxide mark, edge overcoated and zinc dust, the oxygen content between 40 and 200 ppm was suggested in the box in addition the oxygen content of at least 40 ppm or the minimum dew point of $-27^{\circ}C$ is required to prevent a zinc vaporization.

• 한국표면공학회지
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• 제26권6호
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• pp.307-315
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• 1993

A study on a new anti-finger printed EGI steel sheet with high corrosion resistance has been carried out to meet the recent requirement of high quality and performance of the pure zinc electrogalvanized steel sheet. The substrate was the pure zinc electrogalvanized sheet with the metallic coating of 20g/$\m^2$. The two differ-ent processes for inorganic(chromating) and organic(resin) coating were applied. One was a two coat/two bake type to separately treat chromating and resin coating which is now widely used. The other was a one coat/one bake type to simultaneously treat them which is newly developed in this study. The solution for the one coat/one bake type was an aqua-base coating agents which was composed of inorganic and organic components. The new anti-finger printed EGI steel sheet with the Cr and resin coating weight of 13mg/$\m^2$ and 800mg/$\m^2$, respectively shows the superior corrosion resistance besides the good paintability, formability fingerprint resistance and earth characteristics properties.

• Corrosion Science and Technology
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• 제13권5호
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• pp.195-203
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• 2014

Modern industry has a wide variety of application areas such as ocean industry, construction and automobile industry. With the current circumstances, the need for anti-corrosion technology that can be used on materials to withstand in harsh environments, is increasing. In this study, we have sought to develop a metal coating technology with zinc and aluminum powders as a potential anti-corrosion material. To make a coating on metal products, a thermal diffusion coating method was used under the conditions of $350^{\circ}C$ for 30 minutes. Optical microscope, Field emission scanning electron microscope (FE-SEM&EDX) and X-ray diffraction analysis were used to analyze a coating layer. As a result, we have confirmed that the generated amount of rust on metal parts coated with thermal diffusion coating method decreased dramatically compared with non-coated metal parts. Furthermore, the anti-corrosion performance was evaluated according to the different ratio of zinc and aluminum. Finally, we confirmed the possibility of application and commercialization of our coating technique on metal parts used in harsh industrial based on the results of these performance.

• International Journal of Korean Welding Society
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• 제2권1호
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• pp.1-10
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• 2002

The thermal contact conductance at different temperatures and with different electrode forces and zinc coating morphology was measured by monitoring the infrared emissions from the one dimensionally simulated contact heat transfer experiments. The contact heat transfer coefficients were presented as a function of the harmonic mean temperature of the two contacting surfaces. Using these contact heat transfer coefficients and experimentally measured temperature profiles, the electrical contact resistivities both for the faying interface and electrode-workpiece interface were deduced from the numerical analyses of the one dimension simulation welding. It was found that the average value of the contact heat transfer coefficients for the material with zinc coating (coating weight from 0 g/$mm^2$to 100 g/$mm^2$) ranges from 0.05 W/$mm^2$$^{\circ}C$ to 2.0 W/$mm^2$$^{\circ}C$ in the temperature range above 5$0^{\circ}C$ harmonic mean temperature of the two contacting surfaces. The electrical contact resistivity deduced from the one dimension simulation welding and numerical analyses showed that the ratio of electrical contact resistivity at the laying interface to the electrical contact resistivity at the electrode interface is smaller than one far both bare steel and zinc coated steel.

• 한국산학기술학회논문지
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• 제18권10호
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• pp.603-610
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• 2017

탄약을 포함한 다양한 산업 분야에서 사용되는 철강 재료는 부식에 취약하므로, 표면 그대로 사용하는 것은 바람직하지 않다. 따라서 도금, 도장, 화성처리와 같은 표면 처리 이후 사용하여야 하는데, 탄약 제조 과정에서는 주로 아연계 인산염 피막 처리가 사용되고 있다. 표면 처리 기법 중 하나인 아연계 인산염 피막은 금속 표면을 화학적으로 처리하여 안정성이 높은 화합물 층을 표면에 고착시키는 방법으로, 크게 도장 하지용 경인산염 피막과 부식 방지용 중인산염 피막으로 나뉘어지는데, 아연계 인산염 피막은 전산도, 철 함량과 같은 여러 가지 인자에 의해 피막의 품질과 내식성이 결정된다. 본 연구에서는 전산도 및 철 함량이 탄약 부식 방지 목적으로 사용되는 아연계 중인산염 피막의 중량 및 내식성에 미치는 영향에 대하여 알아보았다. 철 함량에 따라 피막의 구조가 치밀해지며, 내식성이 향상되는 결과를 확인할 수 있었으나, 전산도는 피막의 두께와 중량에만 영향을 주고 내식성에는 큰 영향을 주지 못하였다. 위 결과를 토대로 탄약 제조 과정에서 사용되는 인산염 피막 처리 공정의 최적 제어 수준을 제시하였다.