• Design & Manufacturing
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• v.15 no.1
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• pp.32-40
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• 2021

Mold design for in-mold coating was carried out to achieve simultaneous injection molding and two-color coating for car gas cap cover. The developed mold includes one core and three cavities which are composed of a substrate cavity and two coating cavities. To provide a sealing edge for complete seal during the second coating, the first coated material was used at the boundary between the first coating and the second one, and injection molded substrate was used at the parting line. The materials used were PC/ABS for substrate and 2-component Polyurea for coating. Through experiments, it was found that the suggested sealing edges were effective for complete seal during the second coating. In cavity pressure traces, there were three peaks caused by mold closing, coating-material injection and cleaning-piston advancement inside the mixing head. The cavity pressure increased with decreasing coating thickness.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.99-107
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• 2003

Normally coating is used a method for protecting reinforced concrete. For this purpose, organic as well as inorganic coatings are used. The advantages of inorganic coatings are lower absorption of UV, non-burning etc. On the other hand, organic coatings have the advantage of low permeability of $CO_2$, $SO_2$ and water. Organic coatings provide better protection for reinforced concrete. However, in organic coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, they have a problem with adhesion. So, we developed coating material, WGS-Eco which was hybridized with polymer and cement based material to protect concrete structures and solve problems of organic coatings. This study was conducted an comparative evaluation on physical and durable performance of developed coating material and previously used coating materials. As a result, the performance of developed coating material was not inferior to organic coating materials. So, the developed coating material was considered as a suitable coating material which had advantages of inorganic and organic coatings for protecting concrete.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.273-276
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• 1995

In this paper, the response characteristics of organic gases were investigated by using quartz crystal microbalance(Q.C.M) with different coating materials. The method for pattern was discussed in order to develope gas sensing system using neural network and pattern recognition. we analyzed the response characteristics by the area of frequency shift, which mean affinities of gases for coating material. The results shows that the Parameter made by the area of frequency shift has possibility to be used for pattern recognition and neural network. we found that each gas had different decrease pattern for coating material.

• Journal of the Korean Ceramic Society
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• v.46 no.3
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• pp.301-305
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• 2009

The novel carbon coating process for interlayer of fiber reinforced ceramic composites between fiber and matrix was performed by carbonizing phenolic resin solution that coated on fiber surface in $N_2$ atmosphere at $600^{\circ}C$ to improve the strength and fracture toughness of CMC(ceramic matrix composite). 160 nm carbon layer was coated on fiber surface with 5 vol% of phenolic resin solution. Since the process temperature ($600^{\circ}C$) is lower than chemical vapor deposition($900{\sim}1000^{\circ}C$), the strength and toughness could be preserved. Furthermore the coating thickness uniformity was improved to 8% of deviation along the stacking sequence. Therefore, prevention from fiber degradation during coating process and controlling coating thickness uniformity along the preform depth were achieved by coating with phenolic resin carbonizing method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.206-209
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• 2003

The purpose of AR and HR coating is acquire the very low reflection rate and the high reflection rate through the deposition of a thin film using the refraction ofmaterial. Basically if the high refractive material and the low refractive material are chosen and the condition for the experiment is determined, then we solve theproject with the optical design and multi thin film coating. First of all, we choose $SiO_2$for the low refractive material and $TiO_2$ for the high refractive material and apply Sputtering System easy to control the refraction rate and excellent in reconstruction to the equipment of thin film multiplication. For the control of the refraction rate and growth rate we modify RF Power and the ratio of Gas(Ar:O2), And we use Ellipsometer for estimation and analysis of the refraction rate and growth rate and AFM&SEM for the analysis of surface and component.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.121-128
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• 2014

PURPOSES : The objective of this study is to evaluate the tack-coating material's properties using the bitumen bond strength(BBS) test and damping test as function of changed curing times. In this study, bonding strength tests were performed according to the curing time of tack coating materials. METHODS : In order to investigate bonding characteristic of tack coating materials, the Pneumatic Adhesion tensile Testing Instrument(PATTI) device is used to measure the bond strength between the tack coating materials and aggregate substrate based on the AASHTO TP-91. Also, damping test as in situ test was used to determine an appropriate traffic openting time for construction vehicle. Four different tack-coating materials were used in this study. The BBS tests were performed a one hour curing and testing temperatures of $5^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$. Damping test was conducted at 30min, 60min, 90min, and 120 min of curing times with temperatures of $20^{\circ}C$ and $30^{\circ}C$. RESULTS and CONCLUSIONS : The BBS test results show various bond strength as function of tack coat materials. At the same testing condition, A tack coat material shows almost two times higher than D tack coat materials although both materials are satisfied the criteria of material's physical properties. Also, Dampting test results shows similar trend with BBS test result. The damping test result was significantly changed as function of tack coat materials. Based on this study, the tack coating material's curing time is very important. Therefore, both curing time and the bond strength's characteristic has to be considered in standard specification.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.10
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• pp.890-896
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• 2009

Li(Ni, Co, Mn)$O_2$ has been known as one of the most promising cathode materials for lithium secondary batteries. However, it has some problems to overcome for commercialization such as inferior rate capability and unstable thermal stability. In order to address these problems, surface modification of cathode materials by coating has been investigated. In the coating techniques, selection of coating material is a key factor of obtaining enhanced properties of cathode materials. In this work, we introduced solid electrolyte (Li-La-Ti-O) as a coating material on the surface of $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ cathode. Specially, we focused on a rate performance of Li-La-Ti-O coated $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ cathode. Both bare and Li-La-Ti-O 2 wt.% coated sample showed similar discharge capacity at 0.5C rate. However, as the increase of charge-discharge rate to 3C, the coated samples displayed better discharge capacity and cyclic performance than those of bare sample.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.425-428
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• 2013

In this paper, we present a novel hydrophilic coating material (Wellture Finetech, Korea) which can be utilized as a coating layer for anti-contamination for electrical and electronic system. The coating material was deposited on 4 inch silicon wafer with several different film thickness. The film thickness was controlled by spin coating speed. After curing of the film, we have scratched by permanent marker to check self-cleaning property of the film. Also we have executed several mechanical tests of the films. As the spin coating speed is increased, the film thickness was thinned from 230 nm to 125 nm. Contact angle of the film was lowered from $30^{\circ}$ to $12^{\circ}$ as the spin coating speed is increased from 700 to 2,500 rpm. On permanent marker scratched film surface coated at 1,000 rpm, we have poured regular city water to investigate self cleaning property of the film. The scratches were gradually separated from the film surface due to super-hydrophilicity of the film. Hardness of spin coated film was 9H measured by ASTM D3363 method. and adhesion of all film was 5B tested by ASTM D3359 method. Also, to get exact hardness value of the film, we have utilized a nano-indenter. As spin speed is increased, the hardness of film was increased from 3 GPa to 5 GPa.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.182-187
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• 2024

Currently, the most developed new energy source is solar energy. Because solar power is installed outside, it is exposed to many pollutants. Pollutants are causing the characteristics of solar energy to deteriorate. Therefore, this study aims to develop a water-repellent coating to prevent contamination of solar modules. Silica and Titania materials are mainly used as water-repellent coating materials. In this study, it was based on silica and the contact angle characteristics were measured according to the change in the amount of silica and ammonia water added and the number of coatings. As a result of the measurement, it was confirmed that the contact angle was more than 60 degrees when 0.5 mol of TEOS was added to 50 mL and 0.15 M when 1 mL of ammonia water was added to 296.47 ml of distilled water. And it was confirmed that the contact angle improved when the number of coatings was applied twice. A water-repellent coating material was applied to low iron tempered glass used to protect dye-sensitized solar cell modules. The characteristics of the module were measured after spraying DI-Water on low-emission tempered glass with a water-repellent coating. As a result of the measurement, the efficiency of the module without application, the efficiency of the module coated once, and the module coated twice were 4.87%, 4.90%, and 4.91%, respectively. It was confirmed that the efficiency of the module increased by applying water-repellent coating. As a result of this study, it is determined that the water-repellent coating material will help improve solar power generation efficiency and lifespan by being self-cleaning and non-reflective.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.25-29
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• 2008

Recently, new functionally graded material(FGM) that has a spatial variation in composition and properties is developed because of its good quality. This material yields the demands for resistance to corrosion and high temperature in turbine blade, wear resistance as in gears and high strength machine parts. Especially coating treatment in FGM surface brings forth a mechanical weak at the interface due to discontinuous stress resulting from a steep material change. It often, leads cracks or spallation in a coating area around an interface. The behavior of propagation cracks in FGMs was here investigated. The interface stresses were reduced because of graded material properties. Also graded material parameter with exponential equation was founded to influence the stress intensity factor. And the resistance curve with FGM coating was slightly increased.