• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.34-40
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• 2005

Laser welding of thermoplastics is a new jointing technique with a host of advantages. It is not only another extremely useful welding method but also a cost-effective alternative to traditional techniques involving screws or adhesives. Transmission laser-welding of thermoplastics such as polycarbonate(PC), polypropylene(PP), polyvinyl chloride(PVC), low density polyethylene(LDPE) and acrylic using a high power diode laser has been studied experimentally. The optical transmission of each plastic has been measured at laser wavelength of 808nm. The weld process has been characterized by the specific energy and weld time required for each plastic. The characteristics of laser welding between same plastics have also been analyzed.

• Photonics industry news
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• s.1
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• pp.66-71
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• 2000

본지에서는 연구개발정보센타(KORDIC)의 자료협조를 받아 광산업과 관련된 해외기술 동향들을 소개한다.

• Journal of the Korean Vacuum Society
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• v.13 no.1
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• pp.29-33
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• 2004

In this paper, we investigated the ultra-low temperature(<$150^{\circ}C$) polycrystalline silicon film on plastic substrate application using RF-magnetron sputtering and excimer laser annealing. Amorphous silicon films were deposited using Ar/He mixture gas at $120^{\circ}C$ and in-film argon concentration was less than 2%, which was measured to Rutherford Backscattering Spectrometry. At energy density 320mJ/$\textrm{cm}^2$, RMS roughness was 267$\AA$ and UV crystallinity was 62%. The grain size varies from 50nm to 100nm after excimer laser irradiation.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.27-35
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• 2000

재료가공분야에의 레이저의 적용은 1960년대 후반부터 시작되었으며, 고출력 CO$_2$ 와 Nd:YAG 레이저가 많은 산업분야에서 보편화될 정도로 발전하여 왔다. 재료가공에서의 레이저의 적용분야는 금속의 절단, 용접 및 드릴링, 세라익의 스크라이빙, 플라스틱과 복합재의 절단 및 여러 가지 재료의 마킹 등을 포함한다. 이와 같은 모든 응용에서 공통적인 것이 레이저 조사에 의해 재료를 용융, 증발시키는 열적 메카니즘이다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.430-433
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• 2005

Laser bonding between similar and dissimilar thermoplastics has been investigated by making use of laser transmission weld technique. Spot welding of two layers of plastic materials has been demonstrated by using of a high-quality diode-laser with 808nm wavelength. Weld areas increases according to power density, exposure time. The results of peel out test show that peel strengths increase with the area of molten plastics. Layers, which have the same chemical properties, have good bonding qualities. A bonding method which dye film is coated on the interface is used for laser bonding between plastics with high transmission for laser wavelength. Laser transmission bonding is worthy of attention because it is not in contact, requires a few tooling devices, allows a flexible energy delivery and produces nearly invisible welds

• Proceedings of the Korean Society of Laser Processing Conference
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• 2002.05a
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• pp.12-16
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• 2002

• Proceedings of the Korean Society of Laser Processing Conference
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• 2001.05a
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• pp.55-58
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• 2001

• Resources Recycling
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• v.26 no.6
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• pp.73-83
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• 2017

Used small household appliances have a wide variety of product types and component materials, and contain high percentage of black plastics. However, they are not being recycled efficiently as conventional sensors such as near-infrared ray (NIR), etc. are not able to detect black plastic by types. In the present study, an automatic sorting system was developed based on laser-induced breakdown spectroscopy (LIBS) to promote the recycling of waste plastics. The system we developed mainly consists of sample feeder, automatic position recognition system, LIBS device, separator and control unit. By applying laser pulse on the target sample, characteristic spectral data can be obtained and analyzed by using CCD detectors. The obtained data was then treated by using a classifier, which was developed based on artificial intelligent algorithm. The separation tests on waste plastics also were carried out by using a lab-scale automatic sorting system and the test results will be discussed. The classification rate of the radial basis neural network (RBFNNs) classifier developed in this study was about > 97%. The recognition rate of the black plastic by types with the automatic sorting system was more than 94.0% and the sorting efficiency was more than 80.0%. Automatic sorting system based on LIBS technology is in its infant stage and it has a high potential for utilization in and outside Korea due to its excellent economic efficiency.

• Resources Recycling
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• v.6 no.2
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• pp.70-77
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• 1997

The paper revlcws [he kinds and thcir physical and chemical characleristics of varlnus plastics. The nccds for ~ccycling of used plastics are emphasized and problems and challcngcs ilssoclatcd with treatments of such used plastics are described It aLra makes various suggestions to meet and solve these problems.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.533-538
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• 2011

A plastic-compatible low-temperature metal deposition and patterning process is essential for the fabrication of flexible electronics because they are usually built on a heat-sensitive flexible substrate, for example plastic, fabric, paper, or metal foil. There is considerable interest in solution-processible metal nanoparticle ink deposition and patterning by selective laser sintering. It provides flexible electronics fabrication without the use of conventional photolithography or vacuum deposition techniques. We summarize our recent progress on the selective laser sintering of metals and metal oxide nanoparticles on a polymer substrate to realize flexible electronics such as flexible displays and flexible solar cells. Future research directions are also discussed.