• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1806-1809
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• 2008

Study that form micro pattern by direct ink jet printing method is getting attention recently. Direct ink jet printing spout fine droplet including nano metal particle by force or air pressure. There is reason which ink jet printing method is profitable especially in a various micro-patterning technology. It can embody patterns directly without complex process such as mask manufacture or screen-printing for existent lithography. In this study, research of a technology that ejects fine droplet form of Pico liter and forms metal micro pattern was carried with inkjet head of piezoelectricity drive system. Droplet established pattern while ejecting consecutively and move on the surface at the fixed speed. Patterns formed in ink are mixed with organic solvent and polymer that act as binder. So added thermal hardening process after evaporate organic solvent at isothermal after printing. I executed high frequency special quality estimation of CPW transmission line to confirm electrical property of manufactured circuit board. We tried a large area printing to confirm application possibility of an ink jet technology.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.1-8
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• 2022

Fused deposition modeling (FDM), based on stacking a continuous filament of polymer or composite materials, is well matured and is thus widely used in additive manufacturing technology. To advance FDM-based 3D printing technology, the mechanical properties of additively manufactured composite materials must be improved. In this study, we proposed a novel FDM 3D printing process using metal wire-polymer composites, enabling enhanced mechanical properties. In addition, we developed a new type FDM filament of copper wire wrapped in nylon material for stable 3D printing without thermal damage during the printing process. After FDM printing of the copper wire-nylon composite filament, we conducted a tensile test to investigate the mechanical behavior of the printed composite materials. The experimental results confirmed that the tensile strength of the 3D-printed metal wire-polymer composites was higher than that of the conventional single polymer material. Thus, we expect that the FDM printing process developed in this study may be promising for high-load-bearing applications.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.6
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• pp.1052-1062
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• 2021

This study aims to confirm the possibility of Ultra-Violet (UV)-printed 3D printing materials using thermal polyurethane (TPU) with CMYK colors by applying an eco-friendly UV digital printing process. A UV-printed 3D printing TPU material was prepared with cycles of UV printing and CMYK colors. Dyeability of the 3D TPU samples with cycles of UV printing and CMYK were analyzed for thickness, weight, surface roughness, reflectance, colorimetry, and K/S values. The thickness and weight of 3D-printed TPU samples with cycles of UV printing are increased with overprints from 1 to 5. The surface roughness of 3D-printed TPU samples with increasing UV prints were decreased, meaning that the surface of TPU samples becomes gradually smoother. The reflectance spectra of CMYK UV-printed TPU samples showed the surface reflectance within each characteristic wavelength of CMYK. The 3D-printed TPU samples, subjected to UV printing twice or more, showed low surface reflectance. After examining the L^*a^*b^* of the 3D-printed TPU samples by the cycles of UV printing, the study found that the more UV got printed more than 2 times, the closer the color to each CMYK.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.59.2-59.2
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• 2011

We have demonstrated ink-jet printed indium tin oxide (ITO) and indium tin zinc oxide (IZTO) electrodes for cost-efficient organic solar cells (OSCs). By ink-jetting of crystalline ITO nano-particles and performing a rapid thermal anneal at $450^{\circ}C$, we were able to obtain directly patterned-ITO electrodes with an average transmittance of 84.14% and a sheet resistance of 202.7 Ohm/square without using a conventional photolithography process. The OSCs fabricated on the directly patterned ITO electrodes by ink-jet printing showed an open circuit voltage of 0.57 V, short circuit current of 8.47 mA/cm2, fill factor of 44%, and power conversion efficiency of 2.13%. This indicates that the ITO directly-patterned by ink-jet printing is a viable alternative to sputter-grown ITO electrodes for cost-efficient printing of OSCs due to the absence of a photolithography process for patterning and more efficient ITO material usage.

• Textile Coloration and Finishing
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• v.25 no.4
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• pp.287-291
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• 2013

Nowadays, terms such as 'Smart Textile', 'Intelligent Textile' and 'Wearable Computing' are commonly used in everyday contexts. And radio-frequency identification (RFID) is the use of a wireless non-contact system that uses radio-frequency electromagnetic fields to transfer data from a tag attached to an object, for the purposes of automatic identification and tracking. These products are required technologies which are textile treatments, printing, ink, etc. Durability of textile substrates is an essential marker for conductive ink printing process. Especially, heat stability is important, since conductive ink should be processable (annealing, curing) at temperatures below $150^{\circ}C$. This study was application of RFID on textiles. The textile pre-treatment processes should be carried out to use RFID antenna on textiles.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.183-185
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• 2008

재택근무와 소규모 창업 등 사무 환경의 변화 에 따라 프린터와 복합기의 소형화가 요구 되고 있다. 이러한 소형화에 의해 프린터 내부의 발열 요소들이 제한 된 공간에 배치되어, 기기 내부의 열 유동 및 발열 개선은 제품의 수명과 안정성 확보를 위한 중요 사항이 되었다. 본 논문에서는 프린터와 복합기의 내부 요소 중 주요 발열원인 전원 공급 장치에 대하여 Computational fluid dynamics (CFD) software 인 ICEPAK을 이용하여 중요 부품의 배치 조건에 따른 대류 와 온도 특성을 확인 하고, 최적화 된 부품 배치 방법을 제안한다. 또한 제안하는 부품 배치 방법을 적용한 초박형 프린터용 50W 급 전원 공급 장치를 제작하여 실제 온도 특성이 개선됨을 확인한다.

• Journal of Technologic Dentistry
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• v.43 no.3
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• pp.71-76
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• 2021

Purpose: In this study, thermal properties were observed by measuring the extent of thermal expansion and the amount of thermal residue that appears upon burnout on a workpiece made by using a dental digital light processing (DLP) three-dimensional (3D) printer. Methods: Thermal properties of workpieces manufactured by using two 3D printers were observed. The specimens were designed in cylindrical form with dimensions 10 mm in diameter and 10 mm in height. The control specimen was made of wax, and the experimental specimen was made of resin. The thermal expansion rate was measured by applying heat to three types of specimens, and burnout residue was measured. Results: The thermal expansion rate of the wax pattern (WP) specimen was 0.93%±0.05%, of the RP1 specimen was 1.30%±0.08%, and of the RP2 specimen was 1.20%±0.09%. Measuring the recovered residue yielded residual amounts of 0.2% for the WP specimen, 1.1% for the RP2 specimen, and 1.8% for the RP1 specimen. Conclusion: 1. From measurements of the workpieces manufactured by dental DLP 3D printing, the thermal expansion rate was found to be higher than that of wax. 2. As a result of measuring burnout residues on the workpieces manufactured by dental DLP 3D printing, the required summoning temperature to obtain suitable castings was determined to >750℃.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.5
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• pp.201-208
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• 2016

Ceramic pigments, which show good thermal and chemical stabilities, have been applied for various industry with development of digital printing technology. Ceramic inkjet printing has advantages of high efficiency of ink usage and eco-friendly process. Thus, the interest of the ceramic pigments with various function and color including CMYK (cyan, magenta, yellow, black) digital primary color is increasing. Here, we investigated the thermal and chemical stabilities of white ceramic pigment for digital inkjet printing process. The microstructure and crystal structure of MgO, $Al_2O_3$, $MgAl_2O_4$, $CeO_2$ were analyzed, and the stability with glaze were evaluated. In order to evaluate the applicability for digital inkjet printing, the chemical stability of white ceramic pigments at high temperature was investigated by characterization of the mixed color properties with CMYK ceramic pigments after firing process.

• Journal of the Korean Graphic Arts Communication Society
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• v.27 no.1
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• pp.49-58
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• 2009

Computer to plate technology(CTP) have become fully commercial. The current wide range of computer to plate system and plate makes many potential customers insecure. This process which began around 1995 has now been successfully completed, so that a wide variety of high performance systems is available. The computer to plate method of producing printing plates eliminates films from the production process, thus reducing costs and shortening production times. To discover the optimization formulation of sensitized materials we were changed formulation of resin and violet solution in thermal sensitizers. Also we were analyzed the CTP plate's surface and the result of coating and development at each sample. we were analyzed the effects of development condition as temperature and speed, the plate wear of printing test in C, M, Y, Bk ink. This paper aims to find out suitable ways that we can develop a domestic CTP plate.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.4
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• pp.51-56
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• 2003

Generally, the build-up printed circuit board manufactured by a sequential process involving etching, plating, drilling, etc, which requires many types of equipments and long lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing a prototype in the development stage. In this study, we introduce a screen printing technology for prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as formation of a liquid resin thin layer, solidification by a UV/IR light, and via hole filling with a conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with the conventional process.