• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.61-66
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• 2011

The purpose of this paper is to design a hydraulic actuator to operate under high pressure conditions. The flow characteristics under design conditions of hydraulic actuator were numerically conducted by commercial fluid dynamic code(ANSYS CFX V11). The numerical analysis was performed by transient technique according to the variation of stroke times, which was changed from 0 to 1 second by interval of 0.01. Turbulence model, $k-\omega$ SST was selected to secure more accurate prediction of hydraulic oil flow. The ICEM-CFD 11 and CFXMesher, reliable grid generation software was also adapted to secure high quality grid necessary for the reliable analysis. According to the simulation results, the flow rate which was supplied to the hydraulic actuator was 30.4l/min. These results are in good agreement with design results within 3.5% error.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.2
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• pp.1-8
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• 2019

The demand and importance of adhesives and paint coatings applied to solid surfaces such as metals, ceramics, and plastics are increasing. In this study, the influencing factors on the adhesive strength between the polymer coating and the metal adherend were investigated by Dolly test when the adhesive or the paint coating was applied on the metal adherend. Two-component epoxy adhesive was used as the adhesive, and EH2350, a two-component epoxy paint for anti-corrosion, was used as the paint. Especially, the effect of adherend metals(Al, Fe, STS, Cu, Zn), surface roughness and surface contamination(tap water, salt water) on adhesive strength was studied as influencing factors. The adhesive strength between adhesive and adherend was different when the type of metal adherend was different even when the same adhesive was used. It was found that spray water cleaning was necessary before the paint coating process on the surface of the oxide contaminated adherend with tap water or salt water. As a result of this study, it was confirmed that Dolly test can be widely used in the future to measure adhesive strength between paint coating and adherend.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.150-154
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• 2000

Coloring admixture is used for take color inside and outside of mortar and concrete, differently form pigment and spray paint take color limited surface. In our country, Using the coloring admixture is very slight and regulation is not yet about it. But that is expected the increase with raising the standard of living. Especially it is used to civil structure like dam and seawall for the environment harmony. Then we observe, in this experiment, the effect of coloring admixture on the material properties of color concrete and propose the suitable mix-proportion of color concrete.

• The KSFM Journal of Fluid Machinery
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• v.7 no.6 s.27
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• pp.7-14
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• 2004

A new electrostatic rotary atomizing painting equipment using air turbine was developed for high transfer efficiency. Based on the overall design requirements of painting equipment, basic design specifications of the equipment parts such as air turbine and atomizing disk ate defined from the present conceptual design model. Air turbine is designed with the section profile of NACA airfoil, and its internal flow field is analyzed by commercial CFD code. Atomizing disk is designed to achieve the ligament type spray of paint with the use of visualization technique. Various experiments and tests are conducted to investigate the spray and the transfer characteristics of newly-designed painting equipment, and the measurement results are compared with the those of conventional painting equipments. The comparison results show the present painting equipment is superior to the conventional ones in the aspects of transfer efficiency and coating surface characteristics.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.684-690
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• 2003

A new electrostatic rotary atomizing painting equipment using air turbine was developed. Based on the overall design requirements of painting equipment basic design specifications of the equipment parts such as air turbine and atomizing disk are defined from the present conceptual design model. Air turbine is designed with the section profile of NACA airfoil, and its internal flow field is analyzed by commercial CFD code. Atomizing disk is designed to achieve the ligament type spray of paint with the use of visualization technique. Various experiments and tests are conducted to investigate the spray and the transfer characteristics of newly-designed painting equipment, and the measurement results are compared with the those of conventional painting equipments.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.138-142
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• 2006

Occupational asthma is commonly known to be induced by isocyanate exposure. Spray painters generally use isocyanates for 2-pack spray painting to coat wooden panel surfaces in the furniture industry in South Australia. Due to a lack of actual exposure data, this study conducted environmental and dermal/ocular monitoring from a company in the furniture industry. According to this study, there was no significant airborne contamination, due to the use of high volume low pressure (HVLP) spray guns, low concentration of hardener in paint solutions and appropriate respirator like full face-air line respirator. There was no significant HDI detection in the general work area around the spray booths. Owing to the use of disposable nitrile gloves during the spray painting, no significant dermal exposure was found. According to color monitoring, there was a possible dermal exposure from surfaces in the workplace, unless either protective gloves were worn or appropriate working practices like clean-up process and storage in a secure places. No eye contamination was detected from the spray painters. No significant exposure levels from inhalational, dermal, ocular were found. The area of most concern was work practices.

• ETRI Journal
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• v.32 no.5
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• pp.695-703
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• 2010

Training is one of the representative application fields of virtual reality technology where users can have virtual experience in a training task and working environment. Widely used in the medical and military fields, virtual-reality-based training systems are also useful in industrial fields, such as the aerospace industry, since they show superiority over real training environments in terms of accessibility, safety, and cost. The shipbuilding industry is known as a labor-intensive industry that demands a lot of skilled workers. In particular, painting jobs in the shipbuilding industry require a continuous supplement of human resources since many workers leave due to the poor working environment. In this paper, the authors present a virtual-reality-based training system for spray painting tasks in the shipbuilding industry. The design issues and implementation details of the training system are described, and also its advantages and shortcomings are discussed based on use cases in actual work fields.

• Journal of Ocean Engineering and Technology
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• v.28 no.2
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• pp.177-184
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• 2014

Heavy duty coating is playing an important role in the field of heavy industry in the development of the shipbuilding and plant industries. Heavy duty coating has the very important function of protecting steel under serious corrosive conditions. The airless tip used for heavy duty coating is an essential part that determines the spray pattern of the paint. This research investigated the injection properties of three airless tips(numbers 521, 523, and 525) by using particle image velocimetry(PIV). The velocity and turbulent intensity according to pressure change with each tip type were investigated by using PIV. If the pressure is greater, the turbulent intensity becomes stronger and the break up of particles becomes bigger as the tip number gets smaller. The velocity is the fastest in the center and decreases in the radial direction.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.1
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• pp.147-154
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• 2020

The exterior finishing of reinforced concrete buildings is one of the important factors to prevent durability and prevent natural environment or disaster such as temperature, snow, wind, rain from the outside as well as external design of buildings. Finishing methods can be divided into wet and dry methods. The wet method using paint is relatively easy to construct, but it requires repair and reinforcement every 1 to 5 years and requires a lot of LCC for maintenance. Finishing method using panel has good durability, but it is difficult to install and expensive. Therefore, in this paper, we evaluate the bond strength for the application of the metal spray method in order to overcome the problems of existing methods. Experimental results show that the sandblast + surface roughness agent(S-R(Y)) has a roughness of 41.16 ㎛ and the bond strength is about 3.19 MPa, which is the highest bond strength. In addition, the grinding + surface roughness agent(G-R(Y)) application showed roughness of about 36.59 ㎛ and secured the bond strength performance of 2.94 MPa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.487-493
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• 2020

Recently, the ministry of environment banned the use of the existing airless method using the spray in painting industrial facilities. Therefore, it is necessary to develop a pressure-roller attached to existing airless painting systems. The hole design of the SUS piping and drum-bases of pressure-rollers currently developed and sold have not been studied in detail, so their efficiency is questionable. In particular, if sufficient paint is not supplied to both ends of the roller, it is necessary to rework with a brush after painting. Therefore, the holes of the drum base need to be distributed so that the paint can flow to both ends of the roller. In this study, numerical analysis was performed to determine the effects of the hole design in the SUS piping and drum-base on the flow patterns of the paint and to suggest more efficient design measures. The analysis results showed that the uniform placement of the holes in the SUS piping is good for the balanced inflow of the paint. For the drum-base, the paint can flow better into both ends of the roller when the holes are concentrated and machined on both ends of the drum-base.