• Food Science and Preservation
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• v.14 no.4
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• pp.364-368
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• 2007

The purpose of this study was to improve the stability and the processing property of vitamin C. Vitamin C was coated according to particle size(80-100 mesh, 100-140 mesh) and mixing ratio(1:1.6, 1:2.5, 1:3(w/w)) with coating solution(8% Zein-DP, 6% HPMC-FCC), and then the quality characteristics of fluidized bed micro coated vitamin C were investigated. The coating efficiency and the thickness of coating film were higher in $80{\sim}100$ mesh particle than in $100{\sim}140$ mesh particles, and coating efficiency was decreased as the coating material was increased. The distribution range of particle was more narrow in mixing ratio of 1:3(w/w) than in the other. DPPH radical scavenging activity was not affected by the particle size and the mixing ratio. There was no difference between the coating materials in terms of the quality characteristics. The optimum coating condition for fluidized bed micro-coating of vitamin C powder was selected as the particle size of $80{\sim}100$ mesh and the mixing ratio with coating solution of 1:3(w/w).

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.278-281
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• 2009

Selective laser sintering(SLS), a kind of rapid prototyping technology, can provide a process to form many types of coatings. Coated layers by selective laser melting are highly influenced by substrate, powder and laser parameters such as laser power, scan rate, fill spacing and layer thickness. Therefore an attempt to fabricate Fe-Ni-Cr coating on AISI H13 tool steel has been performed by selective laser sintering. In this study, Fe-Ni-Cr coating was produced by experimental facilities consisting of a 200W fiber laser which can be focused to 0.08mm and atmospheric chamber which can control atmospheric pressure with Ar. With power increase or energy density decrease, line width was decreased and line surface quality was improved with energy density increase. Surface quality of coating layer was improved with fill spacing optimization or layer thickness decrease.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.52-62
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• 1995

In the laser surface hardening process the geometrical parameters, especially the depth, of the hardened layer are utilized to assess the integrity of the hardening layer quality. Monitoring of this geometrical parameter ofr on-line process control as well as for on-line quality evaluation, however, is an extremely difficult problem because the hardening layer is formed beneath a material surface. Moreover, the uncertainties in monitoring the depth can be raised by the inevitable use of a surface coating to enhance the processing efficiency and the insufficient knowledge on the effects of coating materials and its thicknesses. The paper describes the extimation results using neural network to estimate the hardening layer depth from measured surface temperanture and process variables (laser beam power and feeding velocity) under various situations. To evaluate the effec- tiveness of the measured temperature in estimating the harding layer depth, estimation was performed with or without temperature informations. Also to investigate the effects of coating thickness variations in the real industry situations, in which the coating thickness cannot be controlled uniform with good precision, estimation was done over only uniformly coated specimen or various thickness-coated specimens. A series of hardening experiments were performed to find the relationships between the hardening layer depth, temperature and process variables. The estimation results show the temperature informations greatly improve the estimation accuracy over various thickness-coated specimens.

• Food Science and Preservation
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• v.30 no.3
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• pp.419-433
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• 2023

Dried apple bugak, a traditional Korean dried food, was made using superfine powders of glutinous rice (GR), non-glutinous rice (NGR), and Wasabia koreana Nakai leaf (WKNL) as coating materials. This study aimed to determine the effect of coating sliced apples with superfine GR powders substitute with superfine NGR and WKNL powders at different ratios. Apple slices coated with superfine GR, NGR and WKNL powders were air-fried and compared with dried and air-fried apple bugak coated with superfine GR powders. The results showed that coating apple slices with superfine GR powders with the addition of superfine NGR and WKNL powders significantly increased oil absorption capacity and antioxidant activity but reduced viscosity, water absorption capacity, total polyphenol, total flavonoids contents, and improved color and structural improvements. Among all the samples, 80:20:5-treated (GR:NGR:WKNL) dried and air-fried bugak showed enhanced quality characteristics. Thus, the results suggested that coating apple slices by the substituting GR superfine rice powders with 10 or 20% of NGR and 3 or 5% of WKNL superfine powders produces good quality dried and air-fried bugak with nutritious characteristics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.78-81
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• 2004

A technical performance of the coating depends greatly on the thickness of painting film or coating film. Therefore the confirmed report of the technique to measure accurately is essential to the coating film thickness for the assessment about a coating quality performance. In this paper, two gap sensors - eddy current gap sensor and capacitance gap sensor - which has a different operating principle were used to measure the thickness of a nonmagnetic substance coating film such as paint, enamel or ceramic that was coated on the metallic material. A capacitance gap sensor was used to measure the distance between the sensor head and a coating film and an eddy current gap sensor to measure the distance between the sensor head and a base metal. Then the thickness of a coating film was obtained by the difference of two measurement value. At this result, the suggested dual sensor can measure an arbitrary film thickness to be coated on a base metal as the measurement value of coating thickness exists accurately within the 2％ error.

• Tribology and Lubricants
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• v.32 no.4
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• pp.125-131
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• 2016

In recent years, thick ta-C coating has attracted considerable interest owing to its existing and potential commercial importance in applications such as automobile accessories, drills, and gears. The thickness of the ta-C coating is an important parameter in these applications. However, the biggest problems are achieving efficient coating and uniformity over a large area with high-speed deposition. Feasibility is confirmed for the ta-C coating thickness of up to 9.0 µm (coating speed: 3.0 µm/h, fixed substrate) using a single FCVA cathode. The thickness was determined using multiple coating cycles that were controlled using substrate temperature and residual stresses. In the present research, we have designed a coating system using FCVA plasma and produced enhanced thick ta-C coating. The system uses a specialized magnetic field configuration with stabilized DC arc plasma discharge during deposition. To achieve quality that is acceptable for use in automobile accessories, the magnetic field, T-type filters, and 10 pieces of a multi-cathode are used to demonstrate the deposition of the thick ta-C coating. The results of coating performance indicate that uniformity is ±7.6 , deposited area is 400 mm, and the thickness of the ta-C coating is up to 5.0 µm (coating speed: 0.3 µm/h, revolution and rotation). The hardness of the coating ranges from 30 to 59 GPa, and the adhesion strength level (HF1) ranges from 20 to 60 N, depending on the ta-C coating.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.267-272
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• 2017

Automotive seat covers with olefin film imported from foreign companies exhibit some problems such as low peeling strength and high burning rate. The traditional manufacturing process requires gas flame or direct heating for the laminating step. This paper introduces an alternative solution that replaces the olefin film and flame lamination method in making automotive seat covers or interior fabrics. We adopt a new manufacturing concept that applies a water-based resin coating to develop a coating system. The coating machine was successfully developed and tested. Results are intended to contribute to improving the quality and productivity of automotive seat cover production.

• Journal of Welding and Joining
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• v.19 no.5
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• pp.512-519
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• 2001

Sink roll has been used in molten Zn-0.2%Al alloy bath of continuous galvanizing line in sinking and stabilizing process of the steel strip in molten metal bath. In this process, although the scraper scraps off the sink roll surface, the dross compounds is builded up on the sink roll surface and the life time of the sink roll is shorten by the dross compounds. The present study was investigated the application of the spray coating layer on sink roll body for improving durability In molten Zn-0.2%Al alloy. Through the durability tests in molten Zn-0.2%Al alloy with various ceramic and cermet coating layer, the optimum bond and top coating material was obtained. As the results, the system of STS430F base metal, WC-l7Co bond and $ZrO_2-SiO_2$ top coating was clarified to be the best quality of durability in molten Zn-0.2%Al alloy.

• Journal of Power System Engineering
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• v.9 no.1
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• pp.57-63
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• 2005

In the calendar and the advertising catalog, the surface is usually coated by coating polypropylene film. The delamination failure of coating film depends on surface roughness and quality of the substrate paper. In this paper, the mechanisms of delamination failure between the coating film and the paper is investigated by using the root cause analysis as one of techniques of reliability evaluation. The papers used in failure analysis are three kind products made by two domestic and one foreign companies. It found that the main causes of delamination failure between the coating film and the paper were the creation of microvoids caused by shape of filler and their growth caused by contraction of paper.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.363-367
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• 2012

DLC (diamond liked carbon) coating of the tungsten carbide (WC) alloy core surface for molding a glass aspheric lens improves the quality of glass lens and the molding core and is characterized by high hardness, high elasticity, abrasion resistance and chemical stability. In this study, the effect of DLC coating of a thin film by means of the filtered AIP (arc ion plating) technique was examined on Ra and shape of the coated surface. Roughness before and after DLC coating was measured and the result showed that the roughness was improved after coating as compared to before coating. It was observed that DLC coating of the WC alloy core surface for molding had an effect on improving the roughness and shape of the core surface. It is considered that this will have an effect on improving abrasion resistance and the service life of the core surface.