• Elastomers and Composites
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• v.49 no.2
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• pp.160-166
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• 2014

The formulation of six basecoats was designed using aluminium pastes for the per-painted system in the automotive. The aluminium pastes contain pancake type metallic pigment, #501, #801, #601 and cornflake type metallic pigment, #750, #770, #790. The relative cure density of the basecoat increased in order of #501, #801, #601, #750, #770, #790. T-bending, impact resistance, and taping adhesion showed increment with increasing cure density. In the appearance( combined factor) test on cornflake type pigment, The basecoat including the smallest particle size pigment, #790 resulted in the best combined factor compared to other two systems(#750, #770).

• Journal of architectural history
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• v.25 no.5
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• pp.15-25
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• 2016

The color that painted on the ground of Dancheong becomes Gachil(basecoat)-Dancheong and underpainting of Moro-Dancheong or Geum-Dancheong. So, the color of underpainting is the most important element that determines impression of the building. Thus, the architecture after using "Sangrokhadan" has different characters from what it had been. In the existing perception toward the background color of Dancheong, it was considered the characters of Korean Dancheong so-called "Sangrokhadan" that paint vertical elements like columns red and upper part of the columns green. But this study examined the color of Dancheong according to the era and region before and after Goryeo Dynasty era, then it reveals that Sangrokhadan technique was applied from the 14th century in the late Goryeo Dynasty. One of the Goryeo architecture, Geungnakjeon Hall of Bongjeongsa Temple is thought to be a previous style that is not applied "Sangrokhadan" technique because old elements are painted red pigment.

• Analytical Science and Technology
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• v.26 no.4
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• pp.245-255
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• 2013

Identification of paint on victim's clothing and a vehicle are valuable for forensic examination when investigating hit-and-run accidents. Automotive paints on clothes are used to prove a victim caused by traffic accident and to identify a suspected vehicle. The comparison of transferred paints between victim's vehicle and suspected vehicle can be an important evidence in reconstructing the accident situation and in discovering the truth. The paints such as white, yellow, red, blue, or black are hard to examine particle shape under a stereomicroscope because of it is not included aluminum, pearl, and mica flakes in the pigments. The aim of this study under forensic aspect is to compare pigment among basecoat layers of solid paints by identifying inorganic elemental compositions and binder resins of pigments using by micro-FT-IR and micro-XRF spectrometer. The pigment samples were analyzed by using two methods of FT-IR: Reflectance and ATR method. Two methods of FT-IR were useful in discriminating binder resins of pigments by comparing characteristic peaks and patterns of spectra. Also, XRF spectrometer could identify the elemental compositions in inorganic pigments of trace paints which are difficult to compare the identification by FT-IR.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2053-2065
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• 2003

The current trend in automotive finishing industry is to use more electrostatic rotating bell (ESRB) need space to their higher transfer efficiency. The flow physics related with the transfer efficiency is strongly influenced by operating parameters. In order to improve their high transfer efficiency without compromising the coating quality, a better understanding is necessary to the ESRB application of metallic basecoat painting for the automobile exterior. This paper presents the results from experimental investigation of the ESRB spray to apply water-borne painting. The visualization, the droplet size, and velocity measurements of the spray flow were conducted under the operating conditions such as liquid flow rate, shaping airflow rate, bell rotational speed, and electrostatic voltage setting. The optical techniques used in here were a microscopic and light sheet visualization by a copper vapor laser, and a phase Doppler particle analyzer (PDPA) system. Water was used as paint surrogate for simplicity. The results show that the bell rotating speed is the most important influencing parameter for atomization processes. Liquid flow rate and shaping airflow rate significantly influence the spray structure. Based on the microscopic visualization, the atomization process occurs in ligament breakup mode, which is one of three atomization modes in rotating atomizer. In the spray transport zone, droplets tend to distribute according to size with the larger drops on the outer periphery of spray. In addition, the results of present study provide detailed information on the paint spray structure and transfer processes.

• Elastomers and Composites
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• v.48 no.2
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• pp.167-171
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• 2013

Weatherability was examined according to aluminum particle size and its orientation used in PCM(Paint Coated Metal). Substrate delamination was checked by different UV transmission rate with QUV$^{(R)}$ (Q-LAB) equipment that can make accelerated UV irradiation. Film was prepared using three different types of conflake aluminum pastes under a PCM coating process and clearcoat was sprayed. UV transmission test results showed low transmission rate when EKART #790 having the smallest particle size and horizontal orientation was used. From the gloss retention results, gloss retention was highest in EKART #790 and followed by #770, #750.

• Journal of Adhesion and Interface
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• v.16 no.1
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• pp.15-21
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• 2015

In this study, rheological properties and flow dynamics in roll coating process of basecoat paints have been investigated for automotive precoated metal (PCM) sheet applications. Various rheological properties for basecoats with three colors (black, blue, and silver), such as shear viscosity data at room temperature and elastic/viscous moduli under thermal curing condition, have been measured using a rotational rheometer. It is found that the relative portion of function groups inside basecoats and their viscosity level have greatly affected the formation of crosslinked networks by thermal curing. Also, operability coating windows for basecoats have been established in three-roll coating process system by observing their flow instabilities such as ribbing and cascade. It is confirmed that rheological approaches applied in this study have been usefully applied to develop environmentally-friendly PCM coating technology and optimally control the coating operations for non-Newtonian PCM paints.