• Journal of the Korean Graphic Arts Communication Society
• /
• v.28 no.2
• /
• pp.101-116
• /
• 2010

Last printing market is changing to high-quality color prints for web offset printing. But, color image reproduction based on the relative sheet-ped printing compared to the way, web offset printing are falling. Moreover, it's difficult to maintain the quality of the web offset print. The reason is the worker's decision to rely on. Therefore, the quality of prints was no difference in uniformity and objectivity. We have thought the reason, that the physical properties of inks such as fluidity, viscosity and tack. In addition, varies depending on the physical properties of paper, such as thickness, smoothness, roughness and porosity. Therefore, we studied the properties of ink and paper on the relations between the properties used IGT printability tester. This study of domestic web offset printing inks and papers on the relationship between physical properties and printability were studied. So, to improve printability will be used as the basis resources for web offset printing.

• Proceedings of the Korean Printing Society Conference
• /
• 2007.11a
• /
• pp.29-43
• /
• 2007

Web offset newspaper prints is the most widely used printing process in domestic printing industry, but there are no industry-wide specifications for press control to assure consistent quality across newspaper printing plants. As newspaper printing becomes more of a commodity and less of an art, it is necessary to develop the print quality specification standard suitable for Korea web offset newspaper printing field. There are a few commonly employed printing standards such as, SNAP(Specification for Non-Heatset Publication) of the US, IFRA(INCA-FIEJ Research Association), J-color (Japan printing machinery association). And there exists KS for domestic standards, however, since it has been directly imported from ISO standards, there are discrepancies in printing materials and media. This paper aims to examine the color reproduction quality of domestic web offset newspaper prints by comparing with foreign standards. Printing experiments on this study have been performed at one of the domestic newspaper printing companies. The color reproduction properties of the web offset newspaper prints are measured by means of densitometry and colorimetry. These measures are evaluated comapratively with the international standards by means of analyzing, the major factors that determine the color reproduction quality of web offset newspapar prints.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.25 no.1
• /
• pp.27-41
• /
• 2007

Web offset newspaper prints is the most widely used printing process in domestic printing industry, but there are no industry-wide specifications for press control to assure consistent quality across newspaper printing plants. As newspaper printing becomes more of a commodity and less of an art, it is necessary to develop the print quality specification standard suitable for Korea web offset newspaper printing field. There are a few commonly employed printing standards such as, SNAP (Specification for Non-Heatset Publication) of the US, IFRA(INCA-FIEJ Research Association), J-color (Japan printing machinery association). And there exists KS for domestic standards, however, since it has been directly imported from ISO standards, there are discrepancies in printing materials and media. This paper aims to examine the color reproduction quality of domestic web offset newspaper prints by comparing with foreign standards. Printing experiments on this study have been performed at one of the domestic newspaper printing companies. The color reproduction properties of the web offset newspaper prints are measured by means of densitometry and colorimetry. These measures are evaluated comapratively with the international standards by means of analyzing, the major factors that determine the color reproduction quality of web offset newspaper prints.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.41 no.1
• /
• pp.52-60
• /
• 2009

A printing defect known as fluting (or waviness) of the web printed by heatset web offset printing process is one of the chronically serious problems deteriorating print quality. In this paper, fluting occurrence on uncoated papers was explored in terms of many printing conditions including drying temperature, fountain solution amount, ink supply, and press configurations. For this purpose, fluting on prints from real press runs was appraised in a quantitative manner. As results, ink supply was a distinctive factor for fluting such that the lower ink amount, the milder fluting. However increase in fountain solution seemed to make fluting severer while the effect of drying temperature was inconsistent for each paper. This result might indicate variable drying requirements for each paper. Thereby it was suggested that the optimum drying conditions related to the printabilities of each paper need to be established to minimize fluting potential. A press with short dryer and drastic cooling unit produced higher fluting. Suggestions for future work were given along with interpretation for the results.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.28 no.2
• /
• pp.31-44
• /
• 2010

Ever since the introduction of offset lithography, an operator have looked for ways to improve the process by reducing need for dampening solution. Lithography like off-set printing is processed using the repellent properties between water and oil, so all inks for lithography printing must work with dampening solution. The dampening solution may cause the emulsification of ink by the printing pressure in the printing nip. Emulsified ink changed viscosity, tack and causes problems such as bad transfer, uniform density and printed mottle. For a high quality web printing, we studied the effect of emulsified heat-set web inks on the printability, such as amount of ink transfer, printed density and uniformity. For this study, we were carried out by using IGT printability tester C1. For determination of ink properties using the spread meter and Thwing Albert Ink-o-meter, and using the densitometer and image analysis for printed quality determination. The experimental results of this study, we look forward to can be used as the basis for improve of the web print quality.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.31 no.1
• /
• pp.39-49
• /
• 2013

Nowadays the printing market has shift from 2D(two dimension) industry to 3D(three dimension) industry, along with IT. With rapidly changing market, it's true that the effort to develop the printing materials and upgrade the printing qualities is produced actively in the country. Particularly, the differences in printing materials can often determine the quality of printings in the printability. In the case of the printability of offset, 9 items(paper, ink, order of printing, ink supply, blowing-up halftone, grey balance, key color(base color), overlap efficiency, quality at the halftone dot reproduction etc.) are usually considered as the important factors and used to estimate the printability at abroad. However, in domestic, ink-jet paper is not used for the printing/publishing by ink-jet printing for digital, but done mainly for offset printing. Because the paper of gloss coated type, which is the ink-jet paper, has high price, it's too hard to manufacture massively printing/publishing. Also, in the case of the paper of uncoated type, in spite of its reasonable price rather than the former, the type of uncoated one also has demerit that the ink-jet paper has a clear difference between the front and the back. Therefore, it's tough reality that Ink Jet paper is hardly taken advantage of as the printing/publishing. Thus, what is done in the first to print and/or publish on ink-jet paper is that the front and the back must be printed evenly, and appropriate to the printability of ink-jet. Although there're some kinds of ink-jet paper in the country, it has not been produced in true domestic production yet. In addition, thanks to the brightness of fluorescence brightening agent, the foreign product can offer the good-qualified one-time printing. But when it comes to the printing/publishing, there're difficulties that it may cause the Ocular Fatigue because of long-term exposure of the eyes to text. This research tries to find out the optimum ink-jet paper in domestic for the printing/publishing by studying on the printability of ink-jet on digital web-printing. And it also tries to look for the paper's brightness which can be reduce the possibility to cause the consumers' Ocular Fatigue.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.31 no.1
• /
• pp.51-64
• /
• 2013

When it comes to current growth trend for the printing process in Asia printing market, offset printing, gravure printing and screen printing are reduced respectively -4%, -19%, -55%. In judging from the fact, the change in the printing production system from mass production on small amount to small production on mass amount is the biggest issue. For this reason, digital printing shows the significant growth. According to the increase of the growth 78% for electro photography way and 67% for ink-jet, it's not enough to catch up with digital printing which is increasing as time goes by to equip with hardware like as digital press. There's been necessary to install the BOD(Book on Demand) system which is the advanced and regular publication edit solution based on web-to-print model in the prepress, and it has made the BOD system be considered in relation to maximization of efficiency and production. Therefore, this research tries to step forward from the POD concept, which is refired to "Print along with the ordered quantities, the ordered appropriate time and the demanded place", so that it could expand the range of the printing/publishing environment using the BOD system, the order-made publication based on automatically operating template. And it tried to make the relation to digital web press on ink-jet method which is adequate to "mass production on small amount" with such advanced concept. This research also aims to use actively BOD solution model to promote the productivity of labor, and then to produce the printings across all related industries, which means to manufacture maximally the products on the shortest time at minimum place through PC equipments.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.11a
• /
• pp.29-38
• /
• 2006

• Proceedings of the Korean Printing Society Conference
• /
• 1995.11a
• /
• pp.4-8
• /
• 1995

본 실험에서는 최근 급 신장된 국내신문인쇄의 윤전지절에 관해 지절발생수준 및 원인에 관해 분석하였다. 국내 신문사의 윤전지절 발생수준은 구미수준이며, 자동계지 (Autopasting)시 지절이 많았다. 전체적으로 국내 신문인쇄정비기술 및 장력수준은 양호하나 전기적친 정비기술, 신문사란 통일된 관리기법이 요구된다. 종이물성측면에서 기존의 인장, 인열강도 등의 관리로는 미소의 상관성 또는 부분상관성으로 전체적인 지절예측에는 한계가 있으며, 인열강도를 현실성있게 표현한 Fracture Toughness(FT)가 상관관계가 있음을 보여주었다. 또한 마찰계수 역시 지절상관성이 기대되는 물성임을 알 수 있었다. 윤전지절은 인쇄기의 불안정과 종이결함이 복합된 결과로 인쇄기의 안정성유지와 종이의 결함을 최소화하는 것이 필요하다. FT와 마찰계수를 이용한 관리기법으로 지료조성 및 펄프의 개질, 초지공정에 응용하여 최적강도 포인트를 찾아야 할 것이다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.39 no.2 s.120
• /
• pp.25-30
• /
• 2007

Recently the use of web offset printing has been increasing, which can provide high print speed, mass production, and high print quality. However, high speed web offset printing has frequently undergone a blistering problem when the printed paper passes through hot air dryers. Blistering occurs in the middle of the base paper or in the coating layer. This paper focused on the blistering occurring in the base paper. In order to elucidate the effect of pigment ratio on blistering, 6 types of coating color were prepared with varying GCC/clay ratios and printability and blistering were investigated focusing on structure changes in the coating layer. When the clay content in the coating layer was increased, surface roughness and surface strength were decreased and paper gloss was increased. In addition, it was found that the coating layer structure with high clay content, which contains lots of discontinuous pores, hindered water vapors to penetrate out and, as a result, blistering occurred.