• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.382-386
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• 2012

A femtosecond laser with 775nm central wavelength and 150 fs of temporal pulse width was used for multi layered glass cutting applications. Ultrashort pulse was effectively used for clean glass cutting with $50{\mu}m$ depth and minimum cutting width. Laser beam was split to two stages and focused on the top surfaces of each layer. Ablation threshold of used glass was measured to be $2.59J/cm^2$. In experiments, 200mW laser power and 1mm/s scanning speed was used for preliminary experiment. Air gap was the major defect occurring parameter and laser power was less sensitive to glass cutting in the experiment. The maximum cutting speed was measured to be 60mm/min with 2kHz, however, Maximum 3m/min cutting speed can be achievable with a commercially available laser with 100kHz.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.16 no.2
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• pp.207-213
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• 2009

Purpose: This study was done to examine how medication contamination in a single-dose glass ampule is affected by minute glass flakes generated in different methods of cutting the ampule. Method: Sixty medication-containing glass ampules were randomly assigned to two groups. The number of glass flakes, resulting from two different cutting methods (with cotton and without cotton), were counted under the microscope. Contamination was evaluated by extracted the medication with a syringe and culturing it in E. coli, coliform, and aerobic bacteria culture media. Result: Fewer glass flakes were found in the ampules when the ampule was cut with cotton. The use of cotton, however, did not significantly change the degree of drug contamination. Conclusion: Although minute glass flakes generated in the ampule cutting operation did not significantly contaminate the medication and the use of cotton decreased the number of glass flakes in the ampules, glass flakes injected into the blood and tissues of the patient remain a risk factor. Therefore, pre-filled syringes or syringes with filters would be alternative methods and safeguards against the possible injection of glass flakes generated while cutting the ampule.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.249-250
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• 2006

Recently FPD(Flat Panel Display) is used in various field to display enormous information. So cutting technique of flat panel display is needed for producing variety display merchandises. In present, cutting methods of flat panel glass includes breaking process. But this process occurs many glass particles. This glass particles are directly related badness of merchandise and falling productivity. In this paper, to cut front substrate glass of LCD and to get optimized cutting condition are tried fur eliminating breaking process with developed glass cutting machine using a Piezoelectric ceramics actuator. It is known that the vibration of Piezoelectric Ceramic have effect in crack proceeding through the analysis of fracture section.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.3
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• pp.6-14
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• 2014

Touch panels are widely used in the modern display industry as the cover glass of smart mobile phones and tablet PCs. Glass cutting machines are commonly used to cut the panels into their proper sizes. Vibration of these glass cutting machines is assumed to be the main factor leading to the creation of burrs, notches, cracks, scratches and chips on the cut surfaces, eventually causing defects of the cover glass. In this study, the vibrations of a glass cutting machine used for the shearing of cover glass components were analyzed through an experiment and a computer simulation. The structural properties leading to vibration were also analyzed in an effort to determine design alterations which can suppress these vibrations. Moreover, each design alteration was applied to a computer simulation model to determine the effect of different alteration on suppressing vibration. The results show that simple design alterations can substantially suppress vibrations of glass cutting machines.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.155-160
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• 2001

In the use of glass fiber reinforced plastics(GFRP) it is often necessary to cut the components, but the cutting of GFRP is often made difficult by the delamination of the compositions and short tool life. Experimental investigation was conducted to evaluate the chip formation of the glass fiber reinforced plastics during orthogonal cutting. The chip formation process, cutting force, and thrust force were studied. The chip formation processes were studied through the use of quick-stop device. Chip-tool contact areas were obtained with the use of the quick-stop device, and observed using optical microscopy after polishing. Cutting force and thrust force were measured through the use of the tool dynamometer.

• Korean Journal of Materials Research
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• v.18 no.5
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• pp.247-252
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• 2008

A laser glass cutting system using a femto-second laser was evaluated for Flat Panel Display (FPD) glass. A theoretical analysis of the ablation threshold and depth is described using an explicit analytic form. Experiments for clean and deep grooves were performed using a 3W femto-second laser, and the relationships between the input energy and the scribing depth as well as the threshold energy are presented. Mechanical breaking after the scribing process was carried out and the results are compared with a theoretical method. It was found that a two-sided LCD panel glass can be cut clearly using the laser cutting method. The methodology was found to be very effective as a mass-production cutting system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.117-122
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• 1998

Glass fiber epoxy composite material is widely used in the structures of aircrafts, robots and other machines because of their high specific strength, high specific stiffness and high damping. In order for the composite materials to be used in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joint must be provided, which require precise machining. In this paper, the machinability of the glass fiber epoxy composite material was experimentally investigated. The results can be summarized as follows : 1. The entrance of hole is very good manufacturing existing, but exit come to occur sever surface exfoliation. 2. The cutting force in drilling of the glass fiber epoxy composite material is decreased as the drilling speed increased. 3. If the glass fiber epoxy composite material is drilling by the standard twist drill, then the hole recommand cutting condition is spindle speed 400∼600rpm, feed 40∼50mm/min.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.403-408
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• 2013

In this paper, the characteristics of ablation processing of the eagle glass by pico-second laser are investigated. The laser ablation is used to process micro forms on materials. The ablation causes little thermal effect and little burr on the surface of eagle glass. In order to examine the characteristics of panic cracks, experiments are conducted under various cutting conditions such as a frequency of 600 kHz, laser powers, scan speeds and number of scan(NS). To minimize the panic cracks, the specimens are heated at $30^{\circ}C$, $45^{\circ}C$, and $60^{\circ}C$ for ten minutes respectively and then they are broken by hands. Laser powers, NS and scan speeds have an effect on glass cutting results. The ablation depths increase with an increase in the laser power and NS whereas the panic cracks decrease with an increase in scan speed. The high temperature on processed specimens reduces the panic cracks and makes good results of laser cutting. The optimal condition for eagle glass laser cutting is found to be at 30 W of laser power, 3 mm/s of scan speed and 500 of NS, respectively.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.5
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• pp.49-56
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• 1987

This paper is a study on the effect of the cutting speed on the tool wear in turning of the glass fiber reinforced plastics. The wear behavior of cutting tool is studied by means of turning, changing the cutting speed and feed in the wide range. Moreover, the theoretical model applicable to the cutting speed of wide range is analysed. The main results obtained are as follows: The relation between the tool wear and the cutting speed is divided into three range in case of the constant cutting distance. 1) At the low cutting speed, the tool wear is independent of the cutting speed, but dependent mainly on the contact length between tool and glass fiber(lst range). 2) At the high cutting speed, the tool wear is independent of the contact length, and dependent on the cutting speed only(2nd range). The tool wear increases in proportion to the cutting speed. 3) At the higher cutting speed than the speed in the 2nd range, the tool wear is independent both of the cutting speed and the contact length(3rd range). 4) In the 3rd range, tool flank wear is constant and is observed that only the wear of cutting edge increases.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.428-433
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• 2015

A non-symmetric laser beam was used for cutting a thin glass substrate and its effect was investigated. In laser cutting of brittle materials, controlling crack initiation on the surface is crucial; however, it is difficult to ensure that crack propagation occurs according to a designed laser path. A lot of deviation in crack propagation, especially at the edge of the substrate, is usually observed. A non-symmetric laser beam generates a non-uniform energy distribution, which enhances directional crack propagation. A 20-W pulsed YAG laser was used for cutting a thin glass substrate. Parametric analysis was carried out and the crack control of the non-symmetric laser beam was improved. A theoretical model was presented and the limitations of the proposed process were also discussed.