• 제목/요약/키워드: coating quality

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A Development of Roller Coating Method by Applying Spray Method (스프레이 방식을 응용한 롤러 코팅 방식 개발)

  • Cho, Hyun-Seob
    • Proceedings of the KAIS Fall Conference
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    • 2007.11a
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    • pp.74-77
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    • 2007
  • Primary charging roller rotated with contacting surface of OPC drum and take charge OPC drum. Owing to this reason, primary charging roller made by elasticity substance with electric conduction. Properties of charging and image changed by class of coating, method of coating and environment. This study developed about coating method to make print image of good quality.

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A Development of Primary Charging Roller for Printer Cartridge (Printer Cartridge용 저압대전체 개발)

  • Cho, Hyun-Seob
    • Proceedings of the KAIS Fall Conference
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    • 2007.11a
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    • pp.170-173
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    • 2007
  • Primary charging roller rotated with contacting surface of OPC drum and take charge OPC drum. Owing to this reason, primary charging roller made by elasticity substance with electric conduction. Properties of charging and image changed by class of coating, method of coating and environment. This study developed about coating material and coating method to make print image of good quality.

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Study on Manufacturing Technology of Coating Yarns for Awning Fabrics (차양막 직물용 코팅사 제조기술에 관한 연구)

  • Kim, Seung-Jin;Lee, Eun-Ho;Heo, Kyeung;Kim, Hyun-Ah
    • Textile Coloration and Finishing
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    • v.27 no.1
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    • pp.35-49
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    • 2015
  • This paper investigated optimum process conditions of coating yarn for awning fabric. For this purpose, the simulation for processability and yarn quality using SPSS statistics package was carried out, and PP/TPO and PET/PVC coating yarns specimens were made with variation of extruder temperature and feed speed of core yarn on the yarn coating machine for examining simulation result. It was revealed that optimum coating conditions of PP/TPO 1000d coating yarn were extruder temperature $150^{\circ}C$, and core yarn feed speed 400~500m/min. Mechanical property and thermal shrinkage of PP/TPO coating yarn made at this conditions were best and core evenness rates of these coating yarns by yarn compression tester were also superior, which was certified by SEM photograph. In addition, these experimental results were coincided with simulation results. It was found that, in PET/PVC coating yarn, yarn physical properties between 1500d and 1200d coated yarns were not shown any difference, and core evenness rates of these coating yarns were superior. It revealed and concluded that these simulated coating conditions are applicable to production field.

Effects of Edible Coating on the Quality Change in 'Hongro' Apples during Storage (가식성 코팅이 '홍로' 사과 저장 중 품질변화에 미치는 영향)

  • Lee, Jihyun;Min, Sea C.;Song, Kyung Bin
    • Journal of Applied Biological Chemistry
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    • v.58 no.1
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    • pp.61-64
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    • 2015
  • As an edible coating, carnauba shellac wax (CSW) and lemongrass oil (LO) solution was prepared to extend the shelf life of 'Hongro' apples. During storage, there were significant differences in the populations of total aerobic bacteria, yeast, and molds between the coated apples and the control samples. The weight loss and vitamin C loss of apples coated with the CSW-LO solution were lower than those of the control. These results suggest that CSW-LO coating can be an effective method for improving quality of 'Hongro' apples.

Corrosion Resistance of Mg-Added Galvannealed Steel Sheets with Nano-Composite Coating

  • Jo, Du-Hwan;Yun, Sang-Man;Paik, Doo-Jin;Kim, Myung-Soo;Hong, Moon-Hi
    • Corrosion Science and Technology
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    • v.19 no.2
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    • pp.57-65
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    • 2020
  • As competition among global automakers intensifies, demand for materials that are better in price and performance is increasing. While steel and plastic materials compete for automotive fuel tanks, plastic materials have advantages such as light weight for automobiles. However, they have high prices. Accordingly, in this paper, four types of Zn-X plated steel sheets, electroplating (X = none, Sn) and galvannealed (X = Fe, Fe-Mg), were manufactured and their applicability as a fuel tank material was evaluated. Nano-composite coating solution with good conductivity was treated on the surface of plated steels using a roll coater and then cured through induction furnace to improve corrosion resistance. Quality characteristics such as corrosion resistance, fuel resistance to diverse gasoline and diesel fuels, and seam weldability were evaluated for the above plated steels. Their properties were compared and analyzed with conventional Zn-Ni electroplating steels. Among the above plated steels, Zn-Fe-Mg galvannealed steels coated with nano-composite coating exhibited better properties than other steels. Detailed experimental results suggest that evenly distributed Mg elements on the coating layer play a key role in the enhanced quality performance.

Effect of Mixing Ratio of Amphoteric and Anionic Latices on Print Quality of Coated Papers (라텍스의 혼합비율이 도공지 품질에 미치는 영향)

  • 강태근;박규재;이용규
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.1
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    • pp.72-79
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    • 1999
  • The binder plays important roles in determining the quality of pigment coating. In addition to its primary role of binding the pigment to the base paper, the binder performs several other important functions. The binder, also referred to as the adhesive, is the dominant in the aqueous phase of the formulation. Thus it plays a major role in determining viscosity, rheology, water release, and setting time for the coating. Latices based on styrene-butadiene dominate the market for synthetic paper coating binders. Consumption is high and is expected to increase further due to the present tendeyncy toward high-solids coating. The purpose of this study is understanding the impact of various parameters of latex(i.e. Tg, Particle size) affecting prontabilities and optical properties of the coated papers, as well as providing basic information on the use of amphoteric latex for improving print qualities of coated papers. Recently, amphoteric latices, Which are cationic at low pH's but turn anionic at high pH's have attracted interests of paper scientists and engineers. Therefore we investigated the effect of the Tg(glass transition temperature) and particle size of amphoteric latex on the coating qualities. We also studied the effect of mixing ratios (Amphoteric / Anionic)of latex on the coating qualities. Our results showed that Tg and particle size of amphoteric latex have to be controlled for optimizing coated paper qualities. The formulation consisting of 10 parts of amphoteric latex and 5 parts of anionic latex gave best results in ink receptivity, smoothness, air permeability, opacity and sheet gloss. If the results hold for the industrial paper coatings, the amount of expensive amphoteric latex can be reduced while achieving best available printing quality.

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Corrosion Resistance of SD460 Reinforcing Rod by Ceramic Coating (SD460 철근의 세라믹 코팅에 의한 내식성 향상연구)

  • Park, Ki Y.;Lee, Jong K.;Hong, Seok W.
    • Corrosion Science and Technology
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    • v.8 no.4
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    • pp.157-161
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    • 2009
  • The corrosion resistance of reinforcing bar was studied to endure the marine environment during shipment. The red rust on the surface did not damage the adherence in the concrete structures, especially in highly alkaline environment, but made the consumer doubt of the quality. The passivation process by alkalization of the quenching water in the tempcore process failed to endure the long shipping period. The ceramic coating by sol-gel process improved the corrosion resistance without damaging the mechanical properties and adherence between concrete and reinfiorcing bar. Optimal concentration of the coating solution and coating temperature were tested. No additional energy was necessary for the coating process by spraying during cooling process, resulting simplified process and low cost. Salt spray test, cyclic corrosion test and atmospheric test were employed to confirm the resistance. The corrosion rates were presented by rating number and polarization resistance. The coating layer was examined by FIB, XRD and SEM etc.

Degradation of Epoxy Coating due to Aging Acceleration Effects

  • Nah, Hwan Seon;Lee, Chul Woo;Suh, Yong Pyo
    • Corrosion Science and Technology
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    • v.5 no.3
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    • pp.99-105
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    • 2006
  • This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

Properties of Coated Paper and Printabilities by Surface Modification of Pigments for Papermaking

  • Cho, Jun-Hyung;Lee, Yong-Kyu;Lee, Yong-Won;Min, Dong-Jin;Kim, Yong-Sik
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.499-504
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    • 2006
  • To improve the quality of coating paper, many areas, such as the manufacturing process of inorganic pigment for the coating, the property change of coating color, the surface design of coating pigment and the productivity of coated paper, were studied. In this study the physical properties and printability of coated paper were compared with the coating pigment to modify the surface of large particle and the coating pigment to mix together the large and small particles. After the coating color was mixed under the same conditions in order that the coating color has the same printability, the printability change caused by the surface modification of coating color was investigated. With the surface SEM of coated paper, the efficiency of the surface modification of coating pigment was investigated. The physical property and printability of coated paper, in addition to the physical properties of coating color, were compared and evaluated. Also, the efficiency of printability was evaluated, changing the mixing condition.

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Print Mottle : Causes and Solutions from Paper Coating Industry Perspective

  • Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.5
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    • pp.60-69
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    • 2008
  • The principal reasons for applying a pigment coating to paper are to improve appearance and printability. The pigment coating provides a surface that is more uniform and more receptive to printing ink than are the uncoated fibers and, in turn, both facilitates the printing process and enhances the graphic reproduction. The improvement in print quality is readily apparent, especially in image areas or when multiple colors are involved. Although pigment coating of paper is to improve the printability, coated paper is not completely free from printing defects. Actually there are a number printing defects that are observed only with the coated papers. Among the printing defects that are commonly observed for coated papers, print mottle during multi-color offset printing is one of the most concerned defects, and it appears not only on solid tone area but also half dot print area. There are four main causes of print mottle ranging from printing inks, dampening solution, paper, and printing press or its operation. These indicates that almost every factors associated with lithographic printing can cause print mottle. Among these variation of paper quality influences most significantly on print mottle problems in multicolor offset printing, and this indicates that paper is most often to be blamed for its product deficiency as far as print mottle problems are concerned. Furthermore, most of the print mottle problems associated with paper is observed when coated papers are printed. Uncoated papers rarely show mottling problems. This indicates that print mottle is the most serious quality problems of coated paper products. Overcoming the print mottle is becoming more difficult because the operating speeds of coating and printing machines are increasing, coating weights are decreasing, and the demands on high-quality printing are increasing. Print mottle in offset printing is caused by (a) nonuniform back trap of ink caused by a nonuniform rate of ink drying, referred as "back trap mottle, and (b) nonuniform absorption of the dampening solution. Furthermore, both forms of print mottle have some relationship to the structure of the coated layer. The surest way of eliminating ink mottling is to eliminate unevenness in the base paper. Coating solutions, often easier to put into practice, should, however, be considered. In this paper the principal factors influencing print mottle of coated papers will be discussed. Especially the importance of base paper roughness, binder migration, even consolidation of coating layers, control of the drying rate, types of binders, etc. will be described.