롤투롤 인쇄 시스템에서의 기판 소재의 거칠기와 표면에너지를 이용한 잉크 전이에 대한 연구

신기현,김호준,Shin, Kee-Hyun,Kim, Ho-Joon 한국반도체디스플레이기술학회 2010 반도체디스플레이기술학회지 Vol.9 No.2

An ink transfer is modeled and experimentally verified using roll-to-roll electric direct gravure printing process. The ink transfer model based on the physical mechanism for the maximum ink transfer rate is proposed, and experimented by the electric printing machine in FDRC for the relations of the maximum ink transfer rates to the printing pressure, the operating speed, the operating tension, the surface roughness of substrates, and the contact angle between substrate and silver ink. The free ink split coefficient and immobilized ink under the maximum ink transfer rate are calculated by the physical parameter in a printing process and contact angle between substrates and ink. Numerical simulations and experimental studies were carried out to verify performances of the proposed ink transfer model. Results showed that the proposed ink transfer model was effective for the prediction of the amount of transferred ink to the substrate in a direct gravure printing systems.

Analysis of Ink Transfer Process for R2R Printing Applications with Non-Newtonian Ink Property

Kyunghun Kim,Taewon Nam,Yang Na 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

FSI occurring in the ink transfer process from the printing to the moving web was investigated using a CFD technique for the application in R2R printed electronics. Analysis for the flow-structure interaction was conducted to assess the deflection and stress distributions of the web. In order to make the present analysis more realistic, the metallic ink was idealized by a non-Newtonian fluid and, the numerical geometry and the ink properties were selected to match those of the real printing production system. Our numerical results showed that both web handling speed and non-Newtonian assumption significantly influenced the shape of the transferred ink. As the web moving speed increased beyond 5m/min, a significant distortion of the transferred ink shape occurred. Also, non-negligible web deflection occurs in all the geometries considered in the present work but the ratio of the web deflection to the line width gets smaller as the web handling speed becomes higher.

고속 웹 이송속도 및 복잡한 롤 패턴 형상을 고려한 R2R공정에서의 잉크전달 특성 해석

김경훈,김소희,나양,Kim, Kyung-Hun,Kim, So-Hee,Na, Yang 한국반도체디스플레이기술학회 2010 반도체디스플레이기술학회지 Vol.9 No.2

Ink transfer process from the printing roll to the moving web was investigated using a CFD technique for the application in R2R printed electronics. In line with the requirement that the web handling speed needs to be increased further for the cost competitiveness, the effects of web moving velocity with relatively complex roll patterns were analyzed. To make the present analysis more realistic, the numerical geometry and the ink properties were selected to match those of the real printing production system. Our numerical results showed that both web handling speed and complex printing-roll patterns influenced the shape of the transferred ink. As the web moving speed approaches towards 30mpm, a significant distortion of the shape of the transferred ink occurred. In the range of pattern width smaller than 100 microns, a phase distortion was also found to occur in all the printing-roll patterns considered in the present work but the ratio of the phase distortion to the line width gets smaller as the width becomes smaller. Thus, the web handling speed and the shape of printing-roll pattern will be important elements for the better printing quality under 100 micron line width range.

The Influence of Aspect Ratio of Dots on Ink Transfer in Gravure Printing Using Conductive Ink

Kyung-Joon Han,Byung-Joon Ahn,Sung-Lim Ko 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

The pattern shape engraved on the gravure printing roll is one of the most important factors influencing ink transfer. This study is focused on the relations between dot geometry engraved on gravure printing roll and the ink transfer during the gravure printing process. The influence of dot width on printed patterns will be demonstrated. Results reveal that as the width of a dot on the printing roll increases, the ink transfer rate also increases. But over a certain size of width, surface uniformity began to recede. Therefore, proper dot geometry on the printing roll should be decided to guarantee good printing quality according to printing conditions and expected performance of the electronic devices.

Analysis on the ink transfer mechanism in R2R application

이상원,나양 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.1

Ink transfer process from the printing roll to the web was investigated using a Computational Fluid Dynamics (CFD) technique for the roll-to-roll (R2R) printing application. A parametric study was conducted to identify the effects of fluid parameters such as viscosity,surface tension and contact angle. To make the present analysis more relevant to the real printing system, a three-dimensional computational configuration for the commercial software was set up using the information obtained from the typical R2R system. Simplified onedimensional semi-analytic model based on Reynolds equation was compared with the CFD results to assess the validity of the results. Pressure distribution states that 1-D analysis is reasonably good in capturing the flow physics. The 3-D simulation with VOF (Volume of Fluid) shows that viscosity is the most important parameter. Moreover, the larger surface tension resulted in smaller amount of ink transfer.

폴리에스테르-폴리아민 분산제의 합성 및 카본 분산 특성

손정매(Jeong-Mae Sohn),육정숙(Jeong-Suk Yuk),이상준(Sangjun Lee),김남균(Nam-Kyun Kim),신지훈(Jihoon Shin),김영운(Young-Wun Kim) 한국트라이볼로지학회 2014 한국트라이볼로지학회 학술대회 Vol.2014 No.10

Polyester-polyamines were prepared to improve the effect on dispersibility of carbon black used for thermal transfer ink. The synthesis of polymeric dispersing agents was completed by two step reactions; initially, polyester was made by polycondensation of 1,6-hexanediol and adipic acid. The resulting polymers having carboxylic acid were linked with polyamine via acid-base reaction. The structure of the polyesterpolyamine was characterized by NMR spectroscopy and Fourier transform infrared spectroscopy (FT-IR). Basic characterizations such as total acid numbers (TAN) (5.0 - 67.5 mgKOH/g), hydroxyl values (27.1 - 67.5 mgKOH/g), and molar masses (Mn = 1.6 - 8.4 kg mol<SUP>-1</SUP>) for the polyester and total base numbers (TBN)(15.3 - 57.1 mgKOH/g), hydroxyl values (33.0 - 79.8 mgKOH/g), and nitrogen contents (1.02 - 3.48%) for the polyester-polyamine were also determined. Thermal transfer inks were prepared with carbon blacks and the polyester-polyamine dispersing agents, and the resulting mixtures were evaluated for printability, adhesive force, storage stability, ink appearance, ink gloss, and processability, showing significant dispersibility for carbon black in the ink. It can be concluded that the dispersibility of the polymeric materials was dependent on the structure of polyamine and the hydrophilicity-hydrophobicity distribution of the polymeric dispersants.

전단박화 효과를 고려한 R2R 공정에서의 잉크전달 과정에 관한 FSI 해석

김경훈(Kyunghun Kim),남태원(Taewon Nam),김소희(Sohee Kim),나양(Yang Na) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

In most of the earlier numerical studies for the practical R2R printing system, the conductive ink was used to be idealized by a Newtonian fluid. Considering the fact that the real conductive ink can be better described by a non-Newtonian fluid with a shear thinning effect, FSI analysis was conducted to investigate the effect of variable viscosity using a CFD technique for the R2R printing process. Numerical results showed that non-Newtonian model representing a shear thinning effect tend to produce relatively lower printing quality than that of the Newtonian model in terms of amount of transferred ink. Also, it was found that non-negligible web deflection occurs in all the geometries considered in the present work but the ratio of the web deflection gets smaller as the web handling speed becomes higher, indicating that the problems associated with the higher web handling speed may be more alleviated in the range of tens of microns than in the range of a couple hundred microns.

디지털 전사 프린팅 폴리 새틴 원단 색차분석

조문환(Cho, Moon Hwan) 한국디지털디자인협의회 2015 디지털디자인학연구 Vol.15 No.3

디지털 텍스타일 프린팅(Digital Textile Printing)은 디자인에서 프린팅까지 전 공정을 컴퓨터로 처리하여, 프린팅 공정 과정을 단순화, 표준화하며 고부가가치의 다품종 소량생산을 가능하게 하는 효율적인 프린팅 방식이다. 이는 90년대 이후 선진국을 중심으로 기존 방식으로는 제작이 불가능한 디자인을 디지털 방식으로 생산할 수 있는 시스템이 등장하기 시작하여 현재 폭넓게 사용되고 있다. 국내에서 가장 많이 사용되는 디지털 텍스타일 프린팅은 폴리 원단에 프린팅 하는 디지털 전사 프린팅 방식이다. 이러한 승화 전사방식에 사용되는 잉크는 초창기 8색(C.M.Y.K.LC.LM. LL.LP)을 장착하여 사용하였으나 비용절감을 위한 새로운 승화 전사 잉크의 개발로 인하여 6색(C.M.Y.K.LM.LC) 승화 전사 잉크와 4색(C.M.Y.K) 승화 전사 잉크를 대부분에 업체서 활용하고 있다. 이러한 상황에서 6색 승화 전사 잉크가 4색 승화 전사 잉크보다 컬러 색상 구현이 높다고 하지만 4색 승화 전사 잉크보다 6색 승화 전사 잉크가 컬러 구현력에 있어 얼마나 차이가 나는지를 몰라 4색 승화 전사 잉크를 적절히 활용하지 못하고 있다. 본 연구는 폴리 원단에 기본이 되는 폴리 새틴 원단을 선정하여 6색 승화 전사 잉크와 4색 승화 전사 잉크의 발색효과 평가를 L* a* b*값을 통해 컬러 사이에서 색상과 색조를 동시에 분석하여 차이점을 분석하고자 한다. 분석 방법으로는 모니터를 통한 캘리브레이션(Calibation) 프로그램을 행한 후 프린팅 전 화면상의 컬러와 프린팅 된 원단의 컬러 차이를 일치시켰고, 이러한 설정으로 폴리 새틴 원단에 프린팅 된 백판기준의 L* a* b*값을 CCM기로 측색하여 정확한 컬러 구현의 차이를 분석함으로써, 6색 승화 전사 잉크와 4색 승화전사 잉크의 발색 구현력의 차이를 통해 폴리 새틴 원단에 비용과 효율성이 높은 4색 승화 전사 잉크를 사용하는 지침을 제공하고자 한다. Digital textile printing is an efficient printing method that enables small quantity batch production of higher-value products to process the entire process to print the design on the computer to simplify and normalize the printing process. Since the 1990s, a system started to appear mainly in developed countries that can produce a production of design in a digital way which was impossible in the conventional method and the digital printing technology is actively used currently in various countries including South Korea, Italy, Israel, the United States, Japan, Germany, Belgium, Australia, Thailand and China. Currently, digital textile printing, which is most actively used in the country, is a digital transfer printing method to print on poly fabric. While the transfer dye ink has been used by mounting the initial eight colors (C.M.Y.K.LC.LM.LL.LP), by developing a transfer dye ink 6 colors (C.M.Y.K.LM.LC) transfer dye ink and 4 color (C.M.Y.K) transfer dye ink are utilized in most companies. In this situation, 6 colors transfer dye ink has higher implementation of color than 4 colors transfer dye ink but 4-color transfer dye ink is not suitably used as the difference of color implementation of 6 and 4 colors transfer dye ink is not revealed. This study is to evaluate the coloring effect of 6 and 4 colors transfer dye ink by selecting poly satin fabric underlying poly fabric using the L* a* b* values to simultaneously analyze the difference between the color and color tone. As an analytical method, this paper matches the difference of the color of the pre-printing screen and one in the printed fabrics after implementing the calibration program using the monitor and it is to provide guidelines for using 4 colors transfer dye ink with high efficiency of cost in poly-satin fabric through the coloring difference of 6 and 4 colors transfer dye ink by the colorimetry of L* a* b* values with CCM machine of white board criteria printed on poly-satin fabric and analyzing the difference in the exact color implementation.

마이크로 그라비아 옵셋 프린팅에서의 유체 전이 공정에 관한 연구

강현욱(Hyun Wook Kang),황위희(Wei-Xi Huang),성형진(Hyung Jin Sung),이택민(Taik-Min Lee),김동수(Dong-Soo Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

To increase the ink transfer rate in the micro-gravure-offset printing, the liquid transfer process between two separating plates is investigated. During the liquid transfer process, in which one plate is fixed and the other one moves vertically, a sessile droplet is separated into two droplets. The volume ratio of the two droplets depends on the contact angles of the two plates. In a numerical study of the ink transfer processes, liquid transfer between two parallel separating plates and between a trapezoidal cavity and an upward moving plate are simulated, as models of the printing of ink from the offset pad onto the substrate and the picking up of ink from the gravure plate by the offset pad, respectively. Also, in experimental study, to obtain various surface contact angles, chemical treatment, plasma treatment, and electrowetting- on-dielectric (EWOD) surface are considered. The transfer rate between two plates is calculated by analyzing the droplet images. From the results, the optimal surface contact angles of the units of the micro-gravure-offset printing can be characterized.

그라비아 프린팅 공정에서 점탄성 잉크와 기판의 계면접착력 평가

유미림 ( Mi Lim Yu ),안경현 ( Kyung Hyun Ahn ),이승종 ( Seung Jong Lee ) 한국화학공학회 2015 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.53 No.1

To produce patterns with high resolution in gravure printing, it is important to increase ink transfer ratio. The ink which has higher affinity with substrate can be transferred more from the roll to the substrate due to the good wettability between ink and substrate. However, it is difficult to evaluate the affinity between the substrate and the ink which is viscoelastic in nature. In this study, we suggest a practical method to evaluate the interfacial interaction between the ink and various substrates.