• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.10
• /
• pp.1146-1152
• /
• 2011

Ink transfer process is very important to determine quality of printed pattern, therefore its mechanism should be understood to control printing quality. Although there have been many attempts to understand ink transfer mechanism by numerical simulation and experimental studies, their model was too much simple to model realistic printing process and our understanding is not enough yet. In this paper we designed ink transfer visualization system to present flow visualization of ink transfer process for gravure offset printing. We considered rotational effect of blanket roll which is related with printing speed and used non-Newtonian fluid as working fluid such as Ag paste. For printing unit, cantilever-type blanket roll is used for convenient visualization of ink transfer. Serial images were captured continuously by using high-speed CMOS camera and long range microscope. We investigated the effects of various design parameters such as printing speed and pattern angle on the ink transfer process. We found more stretched ink filament for non-Newtonian fluid than Newtonian fluid. As increasing printing speed, length of stretched ink filament and height of break-up point are also increased. We also compared ink transfer process between CD and MD pattern and its relationship with ink transfer mechanism.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.3
• /
• pp.276-281
• /
• 2019

Food printers must use food ink cartridges approved by the Ministry of Food and Drug Safety (MFDS). A 2D bar code is used to read whether the ink cartridge is authentic. However, since the dye is diverged by heat pressure and printed, the barcode is contaminated. In this paper, we propose a pre-processing algorithm to solve the problem of barcode contamination by food coloring dust in a latte art printer. The algorithm is based on various morphological operations. We apply this algorithm before reading contaminated barcode images with a general QR code reader. It has been confirmed that, as compared with the existing QR code reader, the contamination rate that can be perceived is increased from 25% to 40% and even at a contamination rate of 45%, the recognition rate reaches 50%.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.398-401
• /
• 2008

Inkjet printing is commonly used in the controlled deposition of solutions of functional materials in specific locations on a substrate, and it can provide easy and fast deposition of polymer films over a large area. which could become a way to manufacturer low cost solar cells. In the present study, inkjet printing technology is adopted to deposit functional layers of PEDOT/PSS solutions and P3HT/PCBM blends for organic solar cell. The results show that merging of separately deposited ink droplets into a continuous, pinhole-free organic thin film could be achieved by a balance between ink property and substrate treatment. As a result, a power conversion efficiency of 2.0% has been accomplished a solar cells applying inkjet technology.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.13 no.1
• /
• pp.1-12
• /
• 1995

Polymeric mesogens having a regularly alternating rigid-flexible repeating structure in the main-chain polymer exhibit distinct even-odd oscillation in their thermodynamic quantities with respect to the number of methylene units in the spacer. The even-odd oscillation depends on the number of methylene groups in the spacer the entropy change at the NI(nematic-isotropic) phase transition becomes less distinct when the linking group is replaced by the carbonate. In our previous work, we have suggested that the characteristics arise from the geometrical arrangement of the linkage. In this work, we have prepared a series of carbonate-type monomer and dimer liquid crystals. The thermodynamic behaviors at the NI phase transition have been compared with those previous reported for the ether- or ester-type liquid crystals. For the dimer series, the orientational order parameter of the mesogenic core was determined by using H-NMR technique. The origin of the difference observed among linking groups was found to the geometrical characteristics of chemical structure.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.23 no.2
• /
• pp.103-115
• /
• 2005

In off-set printing or coating process, it transfers ink on plate by rolling system. As Ink flows between rolls have an influence on printability of the final products, it needs to be studied scientifically and then control its values. Ink flows between rolls are processed under the effect of diversity factors such as rhelogical properties, printing speed, temperature, humidity etc. Therefore, this study try to approach the real ink transfer mechanism to be concerned about all sorts of variables.

• Korean Journal of Materials Research
• /
• v.16 no.10
• /
• pp.599-605
• /
• 2006

N-(3-triethoxysilylpropyl)-1,4-diaminoanthrquinone-2,3-dicarboximide (TESP-DADI), an organic blue pigment, has been prepared and incorporated into silica solid matrix reacting triethyl orthosilicate (TEOS) via sol-gel method. Morphology and microstructure of resulting hybrid pigment were studied employing SEM and TEM. The micrographs and particle size distributions showed that uniform pigment can be obtained employing TEOS-based sol-gel method forming silica core. Particle size distribution of dispersed pigment in water was examined using the technique of dynamic light scattering. The ensuing pigment dispersion ink was subjected to various physicochemical evaluation such as viscosity, surface tension, inkjet stability, storage stability, and color change as inkjet ink using spectrophotometric, and microscopic techniques.

• The monthly packaging world
• /
• s.289
• /
• pp.45-66
• /
• 2017

(사)한국포장협회(회장 신동호)는 지난해 9월 1일부터 총 92개 회원사를 대상으로 '회원사 실태조사'를 추진했다. 회원사의 매출규모를 비롯해 재직 인원, 연구개발 및 품질관리 실태, 또 내수 및 대외 수출 활동 현황, 경쟁력 여부 등을 조사 분석한 후 2017년 5월 '2016년도 (사)한국포장협회 회원사 실태조사 결과 보고서'를 발표했다. 이 보고서는 연포장 가공, 필름 및 시트, 알루미늄박, 그라비어잉크, 제판, 인쇄기계 및 부품, 기타 부자재 생산 및 판매를 조사 분석하여 신뢰성 있는 통계자료를 만드는데 초점을 맞춰 실시했다. 협회 관계자는 "조사사업을 통해 협회 회원사가 국내 패키징산업에서 차지하고 있는 비중을 파악하고, 국내 및 외국 바이어들에게 우리협회 회원사의 생산능력과 생산기술 등을 소개하는 자료로 활용할 뿐만 아니라 도출된 통계 자료를 바탕으로 패키징산업에 대한 대정부 지원을 유도하고, 협회가 추진하고 있는 해외수출사업의 지원 자료를 위한 기초 자료를 만들 계획"이라고 소개했다. 또한 "이 보고서는 회원사는 물론 패키징업계가 공유해 과잉투자, 과당경쟁방지에도 활용할 예정"이라고 말했다. (사)한국포장협회는 2년마다 전 협회 회원사를 대상으로 실태조사사업을 실시하고 그 결과를 발표하고 있다. 다음에 '2016년도 (사)한국포장협회 회원사 실태조사 결과보고서'의 주요 내용을 살펴보도록 한다.

• Korean Journal of Materials Research
• /
• v.16 no.7
• /
• pp.422-429
• /
• 2006

Studies were performed on preparation of organic-inorganic hybrid silica dye in a dispersing ink system. The silica was subjected to surface modification using 3-aminopropyltrimethoxysilane (APTMS) in order to promote the chemical reactivity of the raw silica. On the surfaces of the aminosilane-functionalised silica, red vinylsulfone-containing azo dye was adsorbed. The dye was found to have chemically reacted with the aminosilane-grafted silica surface, which was proven by FT-IR spectra. Studies on morphology and microstructure were performed employing scanning electron microscopy. The SEM micrographs and particle size distributions showed that a homogeneous pigment can be obtained employing silica as a core. Particle size distribution was also examined using the technique of dynamic light scattering. The ensuing pigment was subjected to various physicochemical evaluation such as inkjet property, storage stability, color change as inkjet ink using printer, spectrophotometric, microscopic techniques. Studies on hybrid dyes from the silica surface demonstrated that, in general, stable pigments for inkjet dispersion ink were obtained.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.2
• /
• pp.103-109
• /
• 2010

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.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2001.11a
• /
• pp.45-45
• /
• 2001

종이 표변에 전분 사이징을 하는 목적은 종이가 액체에 대하여 침투저항성을 부여하 여 종이의 인쇄적성을 향상시키며 아울랴 종이의 표면적성과 종이강도 등의 물리적 특 성을 향상시키기 위해서 사용된다. 표면 사이징은 기본적으로 종이 표면에 전분을 이용 한 필름을 형성하여 종이 표면의 공극크기를 줄여 인쇄잉크 등과 같은 액체의 침투속 도를 늦여준다. 현재 국내에서 널리 사용되는 표면 사이징용 전분으로는 산화전분과 자 가변성용 일반전분이 있다. 자가변성용 전분은 효소나 APS로 전분의 chain 길이를 적 당한 점도로 잘라주는 것으로 전분 호액의 노화가 쉽게 일어나는 경향이 있다. 산화전 분은 전분회사에서 산화제를 이용하여 전분의 점도를 사용자의 요구에 따라 조절한 것 으로 water holdout이 개선되고 자가변성용 전분보다는 노화 안정성이 개선되지만 종 이 내부로의 칩투가 많이 일어나 전분 필름 강도가 약해지며 표면 강도 향상 효과가 적고 종이의 광학적 특성을 저하시키는 단점을 지니고 있다. 또한 약 10 ~ 20% 정도 사 용되는 파지의 재활용시 펄프 섬유에 흡착되지 않는 전분으로 인해 백수 내의 COD 및 B BOD를 증가시키는 원인이 된다.따라서 본 연구에서는 펄프 섬유와 친화력이 높아 지료 내첨용 지력증강제로 널리 사용되고 있는 양성 전분의 양이온 치환도 및 점도를 사이즈 프레스에 적합하게 조절 하여 백상지 제조업체의 라언에 적용하였다. 결과분석 항목으로는 파지 재활용에 따른 백수내 COD, 칼숨 이온함량 등의 백수 시스템의 변화와 종이의 물리적, 광학적 특성 및 ink jet 용지의 인쇄적성 등을 측정하여 산화전분과 비교하였다. 그 결과 약 20%의 C COD 감소 효과와 10%정도의 OPR 향상 효과를 얻을 수 있었다. 종이 물성의 경우 인 장강도와 뺏뺏이(stiffness) 및 지분 등을 측정한 결과 산화전분 보다 향상되었다. 특히 지분의 경우, 참여한 회사의 지분관련 complain이 약 80% 정도 감소하는 결과를 나타 내었다. 또한 백상지의 경우 ink jet 프린터에 많이 사용됨으로 ink jet 프린터의 인쇄 적성을 image analyzer로 측정한 결과 산화전분 보다 향상된 결과를 나타내었다.