• Korean Journal of Materials Research
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• v.27 no.2
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• pp.82-88
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• 2017

Ink-jet printing techniques with ceramic ink, which contains ceramic pigments as colorant, are in increasingly use in the ceramic industry. Generally, ceramic pigments that are produced by conventional method show diameters of several micrometers; these micrometer sized particles in the ink-jet printing process can cause undesirable behavior such as print head nozzle clogging. To prevent this problem, a particle size reduction process is required. In this study, CMYK (cyan, magenta, yellow, black) pigments were synthesized via solid state method. Each pigment particle was milled to submicron size by an attrition mill. The effects of micronizing on the morphology, mechanical property, crystal structure and color property of the CMYK ceramic pigments were investigated by field emission scanning electron microscopy (FE-SEM), particle size analysis (PSA), X-ray diffraction (XRD) and CIE $L^{\ast}a^{\ast}b^{\ast}$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.667-668
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• 2011

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.41-45
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• 2010

This study was performed to evaluate the effect of paper property changes by internal addition of surface strength agent on printability. Advances in printing technique has required the development of paper qualities in many aspects. Basically paper structure is composed of hydrogen bonds which induce many problems in high speed printing machine because of weak bonding strength. One of the important printing problems is surface picking when mechanical pulp or recycled pulp are used. It was caused by the ink-stained blanket in printing process because accumulations of pollutant in white water and other elements which are bonded weakly or do not have hydrogen bonds. Debris at paper surface adheres to blanket which deteriorates printing efficiency and causes various problems. To complement these problems, Pennocel 5137 of polysaccharide structure was used as an agent to improve paper's surface property, strength and printability. Paper surface picking was analyzed by RI-1 test. As the dosage amount increased tensile strength, fiber bonding strength and ZDT strength were improved. Further more formation, smoothness and surface picking resistance were improved. It was confirmed that when adding polysaccharide structure polymers to improve surface strength such as surface picking resistance, it was also possible to improve tensile strength, fiber bonding strength, formation and smoothness.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.191-196
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• 2022

In this study, the anisotropic mechanical property of fused deposition modeling three-dimensional (3D) printing based on lamination direction was verified by a tensile test. Moreover, the property was applied to solid isotropic materials with penalization-based topology optimization. The case of the lower control arm, one of the automotive suspension components, was considered as a benchmark problem. The optimal topological results varied depending on the external load and anisotropic property. Based on these results, two test specimens were fabricated by varying the lamination direction of 3D printing; a tensile test utilizing 3D non-contact strain gauge was also conducted. The measured strain was compared with that obtained by computer-aided engineering response analysis. Quantitatively, the measurement and analysis results are found to have good agreement. The effectiveness of topology optimization considering the lamination direction of 3D printing was confirmed by the experimental result.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.22-31
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• 2002

In this paper, PVA(polyvinylalcohol), oxidized starch and SBR latex were used as binders for ink-jet printing papers, and their effects of the type and blending ratio of binders on ink-jet printing properties were compared. In case of coating color using PVA mainly used for a binder in ink-jet printing, spreading of printed letters decreased and excellent images were manifested resulting from strong hydrophilic of PVA. However, increasing solids content of coating color was somewhat limited because of the interaction of PVA and functional groups in silica as well as high molecular weight of PVA. When oxidized starch and SBR latex were mixed with PVA at desirable ratio to solve these problems, runnability in coating process was improved and good printing properties were shown. Gloss was improved when latex was used along with PVA as a binder because of the thermoplastic property of the latex. From this result, possibilities of high solids content and high gloss ink-jet printing papers were investigated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.4 s.112
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• pp.52-59
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• 2005

Most of printing paper market today have been occupied by western paper and some machine-made Hanji used don't show the characteristic advantages for traditional hand-made Hanji. Although hand-made Hanji has an aesthetic and qualitative value, it has limited uses because of poor printability as printing paper. Unlike western paper, conventional Hanji cannot be used as Printing paper because it is impossible to make the clear formation of printed dot and to develop a high level of sizing and picking problem occurs during printing. Improvements of physical and optical properties such as roughness, smoothness, air permeability, contact angle, opacity, and paper gloss as well as sizing level were accomplished through internal and surface sizing and calendering, which made the paper better suited for printing and decreased problems during printing.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.6
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• pp.1074-1087
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• 2022

This study reports an optimization of a 3D printed wrist brace (WB) for various tilting angles (0°, 45°, 90°) of the re-entrant (RE) pattern and thickness (2 mm, 4 mm) using thermoplastic polyurethane (TPU) filaments and thermoplastic elastomer (TPE) filaments. The actual printing time, weight, Poisson's ratio, and tensile property of the manufactured samples were analyzed. The results confirmed that the actual printing time and weight increased with increasing thickness, regardless of the filament type. All tilting angles of the WB showed a negative Poisson's ratio (NPR), the largest of which appeared at 90°. The results of the tensile property analysis showed that a 90° tilting angle also had the largest value of elongation and stress. From these results, we conclude that the most suitable wrist brace is one in which the actual printing time is low, the weight is minimized to a thickness of 2 mm, and the tilting angle of the RE pattern is 90° for good shock absorption. The choice of filaments may be decided upon according to the user's preference, since the TPU is stiff and the TPE is elastic.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.23-31
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• 2015

With the expiration of main patent of printing method, public interest now has shifted to 3D printing. In this, it needs to shine a light on the negative effects, particularly in the socio-economic aspect of 3D printing. By analyzing the existing research findings, policy reports and press releases, the negative effects of 3D printing and its countermeasures were derived. The main drawbacks of 3D printing includes the following: It might cause 3D printing-related crimes(e.g. printed weapons, intellectual property infringement, etc.) and it poses a big threat to other related business sectors.(e.g. potential job loss in molding and medical equipments manufacturing industries) What's more, the nature of 3D printing that it is easy to operate attracts lots of people, which then leads to serious social and environmental problems-product liability, ethical issues, environmental pollution, and finally government's blindly excessive investment in 3D printing. To avoid such potential risks, the government should establish and enforce the institutional law, and guidelines. Government's rational investment decision is also inevitable for the short-term and long-term sustainability of 3D printing.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.7-14
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• 2010

This paper describes the effects of kinetic parameters such as attaching speed, attaching time, and dettaching speed on printing property of electrodes which were fabricated by micro-contact printing with Ag ink. In inking process the attaching speed was preferable to be less than 1 mm/s, attaching time as short as possible, and detaching speed larger than 1000 mm/s in order to obtain the transfer ratio of ink larger than 98%. Meanwhile in printing process the parameters were totally opposite to the results of inking process; attaching speed larger than 100 mm/s, attaching time larger than 30 sec, and detaching speed less than 1 mm/s for the best results. With the parameters we could obtain the micro-contact printed electrodes with the minimum line width of $30\;{\mu}m$, thickness of 300~500 nm, roughness less than 50 nm, and resistivity of about $15{\sim}16{\mu\Omega\cdot}cm$.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.2
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• pp.199-211
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• 2004

The drying speed of gravure ink are very fast because of evaporation drying type. The gravure ink are fitly selected variety resin and solvent for a wide range printing are adopted. Moreover, after-manufacture handling is necessary to various purposes. Though composition of gravure ink are same those of another printing ink, the viscosity of it are vary low compare with another printing inks. As property of variety printed matters, improvement of performance of printing layer and suitable after-manufacture handling, the more research of gravure ink are to be continue for development of printing technology. Generally, the gravure ink are made up resin, pigment, solvent and additive. Especially solvent are fitly selected for solution of resin, viscosity, and drying speed. Furthermore, it tis care of bad smell of remaining resin, poison and danger of fire of it. Because of the prevention of air pollution as restriction deflation of solvent, custody of dangerous object and improvement of work environment as labor safety hygiene and fire-low, the environment restriction of printing business become strict. This study has purpose of development of gravure ink of involved 30% below of alcohol is used for PVC film printing.