• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.622-626
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• 2008

We have investigated the inter-relationship between the ink-jet printability and the physical fluid properties by monitoring the droplet formation dynamics. Printability of the fluids was judged based on the inverse of Ohnesorge number ($Z^{-1}$) that relates to the viscosity, surface tension, and density of the fluid.

• Journal of the Korean Graphic Arts Communication Society
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• v.10 no.1
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• pp.23-33
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• 1992

The negative pressure distribution curves of the exit of printing nip were obtained by the transducer type tackometer. As the results, found that the elasticity of rubber rollers and pastic viscosity affect to the maximum negative and positive pressure but, the gap of the printing nip didn`t affects to the tack values of ink and ink film thickness. Ink spritting is accured by negative pressure and inks viscoelasticity. And the tack value is affect by properties of the vehicle component in the inks.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1457-1458
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• 2009

The fundamental parameters controlling ink-jet printing liquids are the viscosity and surface energy. The wetting contact angle determines the spread of a liquid drop on the surface and depends on the relative surface energy. The characteristics of silver ink-jet printing were studied with control of surface energy and head temperature. Polyethylene terephthalate(PET) film and Si-wafer(ptype) were used as substrates and atmospheric plasma was treated to control the surface energy. With silver ink, the hydrophilic surface treatment could reduce the radius of droplets due to the hydrophobic nature of silver ink.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.65-70
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• 2011

These days, printed electronics attract attention from electronics industry. In this paper, the fabrication of the fine patterns by Near Field Electro Spinning (NFES) was studied by using Ag ink on silicon wafer (substrate). Two types of ink, the high viscous ink Ag-200 and low viscous ink Ag-15, were used. The fine and uniform patterns were easily fabricated by using Ag-200 because jet breakup is less occurred in high viscosity solution. As increasing flow rate of solution, aspect ratio of Ag pattern decreased. And there was optimum applied voltage for fine pattern. In case of Ag-200, the optimum applied voltage was about 2.02KV. When pattern was fabricated by NFES, the pattern width and height were affected by many factors such as viscosity, flow rate of solution, applied voltage etc.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.3
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• pp.123-129
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• 2018

Ink-jet printing technology with ceramic ink of the four digital primary colors (cyan, magenta, yellow, and black; CMYK) can provide stable coloration even in the high-temperature firing process. Ceramic ink-jet printing can be widely applied in construction and ceramic industries due to the advantages of accurate and fast printing process of digital images for various products. Generally, organic solvent with proper viscosity and surface tension has been used in digital ink-jet printing process. However, the needs of ceramic ink without VOCs emission is increasing. In the present study, eco-friendly ceramic ink was synthesized by combining alumino boro-silicate glass frit and $CoAl_2O_4$ inorganic pigment based on an aqueous solvent that does not generate VOCs. The rheological properties and dispersion stability of aqueous ceramic ink were optimized. Jetting behavior and printing characteristics of the ceramic ink were also investigated in detail. As a result, the formulated aqueous ceramic complex ink showed a suitable jetting behavior without satellite drop by adjusting viscosity and surface tension. The ceramic ink can be printed on glass substrate with minimized spreading phenomena duo to high contact angle.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.4
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• pp.258-265
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• 2016

Digital printing has been used in various industrial areas, including semiconductor manufacturing and textile printing. However, implications on ceramic textile have not been well established so far. Printing high-viscosity materials requires an understanding of their behavior. An inorganic high viscous material with a viscosity range of 20-30 cps is analyzed using a viscometer and through X-ray diffraction. In this study, a digital printer is designed and assembled using a high-viscosity material with software for PC control, resulting in reduced processing at a fast area velocity of $20m^2/hr$. The present study demonstrated that the printer is capable of controlling the shape of the drop mass to smear ink smoothly onto the ceramic surface under an economic budget. In addition, to avoid any difficulty in color management, the ceramic printer is equipped with an independent color management system designed to cope with images on a highly viscous material.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.3
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• pp.53-58
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• 2002

This paper was performed to investigate the effect of pore structure on ink residual behavior. To prepare different coating structures as substrates against inks, fine, medium and coarse calcium carbonate were used in the coating color. It is well known ink properties can affect to print qualities. After printing on the coated paper, ink layer can consider as third structure addition to paper and coating layer. To compare effect of ink properties on the surface structure and print qualities, several properties of ink were also adopted as raw material. Particle size of pigment effect on gloss evaluation of coated paper increased with calendering. It was shown that ink transfer rate increased as surface of the sample was smooth. The ink contained low viscosity resin evaluated more print gloss. Finer pigment particle size, smaller pore size and higher porosity. Pore volume of coated paper was slightly decreased with printing as the coating was prepared with the finest particle size. However, it founded that ink resin could not affect on pore volume and distribution of printed paper

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.2
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• pp.75-87
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• 2003

Printing inks are mainly composed of pigment and vehicles. Among these components, the Vehicle affect the rheologic property of the ink the most but pigment content of characteristic also after to the fluidity property not less than the vehicle. In the study, It is tested effect to the ink fluidity and structure recovery according to change the pigment particle size. The ink fluidity have been observed by using rheometer at the various conditions and it has been tested to observe what the ink fluidity has different means. In result We have found that the viscosity value of the low shear rate range has relatively higher value with decreasing the pigment particle size in the ink. Also, it has been found that when the pigment particle size decreases, the yield stress gradually increase. In the case of ink's structure recovery, when the pigment particle size decreases in the ink, the less changing shear rate, and it takes less time to recover.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.59-75
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• 2005

In gravure printing, the amount of ink from cells has a great effect on the qualities of final printed products. And printability of final products is determined by every kinds variables. Ink transfer process is not verified scientifically because gravure cell is of small size and print speed is rapid. Therefore in order to study of ink transfer mechanism, this study is using the Computational Fluid Dynamics Evaluation. Polyflow 3-10 simulation software is used for considering of non-Newtonian flow. Among the various factors, this study have dealt with gravure cell types used computer simulation in order to define distinctive features in ink flow and transfer. The results of simulation, it defined the distribution of pressure, speed, stream function, viscosity, shear rate during the gravure printing. It is fined out the difficulties and characteristics according to the shape of cell types. Through this study, the condition of gravure printing is depending on the print condition and characteristic of cells.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.12
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• pp.1017-1023
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• 2007

This study is intended to analyze the effect of thin ink-film thickness around rotating printing roll on the printing quality in the gravure printing process which is used for making electronics circuit like a RFID tag with a conductive ink. The present work numerically estimates the film thickness around rotating roller partially immersed in ink for which the volume of fluid (VOF) method was adopted to figure out the film formation process around rotating roller. Parameter studies were performed to compare the effect of ink properties (viscosity, surface tension), operating condition (roller rotating speed, initial immersed angle) on the film thickness. The result indicates that the film thickness has a strong dependency on the rotating speed, while the surface tension has negligible effect.