Journal of Printing Science and Technology
Online ISSN : 1882-4935
Print ISSN : 0914-3319
ISSN-L : 0914-3319
Volume 51, Issue 3
Displaying 1-7 of 7 articles from this issue
Special Review
  • Taira IWAI
    2014 Volume 51 Issue 3 Pages 156-162
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    With the development of the ultraviolet (UV) 10-color press, the world's first "high-definition UV printing method (using 10-micron dots)" has been commercialized to maximize the advantages of UV printing (increased production efficiency, volatile organic compounds-free and thus environmentally friendly, and adaptable to special substrates) and high-definition printing (detailed photographic reproduction, greatly reduced ink usage, and consistent machine maintenance) .To put this special printing method into practice, not only was a new printing machine developed and custom-built, but also research and development into the ink, dampening solution, and machine settings was carried out over many years. Ultimately, the UV high-definition printing method was combined with the Japan color system, which is compatible with international standards, to prove it is possible to control the detailed printing conditions during daily operation. This method is utilized for two-pass, high-density printing on plastic substrates with the four primary color system, on deposited aluminum by using a perfecting unit (single-pass printing on both sides), and on coated paper by merging waterless printing with the current method. A topic requiring ongoing research is energy-saving, since large amounts of electricity are required for the curing of UV inks. This topic is part of our ongoing agenda, and it presents a challenging task.
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  • Kenji UEDA, Koji ETO
    2014 Volume 51 Issue 3 Pages 163-166
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    Lippmann holograms are produced by recording interference fringes in photopolymers. Therefore, they are thicker than an embossed hologram, which can cause issues with transfer. In this report, we briefly study previous developments related to Lippmann holograms, particularly for recording materials, and discuss the recently developed spot transfer Lippmann Hologram that was reported earlier this year. The spot transfer foil is expected to find applications in high-security applications such as banknotes and government-issued identity documents.
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  • Akira TERADA
    2014 Volume 51 Issue 3 Pages 167-171
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    Recently, the development of high-value-added products using printing technology has become commonplace. We have developed and introduced a new type of indicator for such high-value added products. The HUMIJUDGE card features a series of printed humidity indicators. To create this card, we use a nonwoven fabric on which we print a moisture-sensitive ink that can sense the level of humidity. Depending on the humidity, the color of the ink varies from blue to colorless. The use of a nonwoven fabric results in the shedding of fewer particles than a cobalt chloride indictor that uses a paper matrix. To prevent color omission when moisture-sensitive ink is printed on a nonwoven fabric, we divide the ink into multiple batches and apply it to the surface to be coated. Because a minimum number of particles are shed, we can pack this card with products that demand a high level of cleanliness.
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  • Takeshi YOSHIKAWA
    2014 Volume 51 Issue 3 Pages 172-178
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    Over the last 30 years, many types of technologies, including special value-added treatments, have been developed in the field of offset printing. Currently, offset printing is a mature technology and almost any flat material can be printed by the offset process. Approximately 20 years ago, digital printing systems became commonplace in the field of professional printing, and their advanced technology is now capable of achieving a high level of print quality and several special features. Although only 2% of all printed pages were printed by digital systems in 2011, the rate of growth is very fast. Komori developed a new UV inkjet digital printing system and exhibited it at drupa 2012 and JGAS 2013. Nevertheless, digital printing systems still have to overcome the issues described in this document if they are to gain market share against offset printing.
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  • Hideki ITO
    2014 Volume 51 Issue 3 Pages 179-184
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    Demand for short run and ultrashort run print jobs such as those for personalized products is growing in the graphic arts industry. In response to this trend, the industry is currently moving away from analog offset printing and toward digital printing. There are several types of digital presses. The Hewlett-Packard Company currently offers an industrial wet electrographic digital press, the characteristics of which differ from those of a dry electrographic digital press. This purpose of this paper is to introduce high-value digital printing using this digital press and functional inks. The author first describes the mechanical structure and printing process of the digital press. Then, the state-of-the-art functions and technologies available for specialty printing are described.
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Original Paper
  • Ken'ichi KOSEKI, Satoshi INOMATA, Kyoung-Mo JEONG
    2014 Volume 51 Issue 3 Pages 185-190
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    Photopolymers have been used in many fields such as hologram recording material, adhesion, printing, dental material, and electronics. However, it has a problem that UV irradiation leads to volume shrinkage with undesirable influence on cured materials. In this study, shrinkage behavior of the cationic polymerization type monomers were evaluated by correlation existing between the chemical structure and reaction behavior of the monomers. As a result, it was clear that the epoxy, oxetane and vinyl ether monomers showed different volume shrinkage types of behavior. In particular, it was found out that alicyclic type epoxy monomer DEB had a unique volume change behavior. The unique volume change behavior of DEB occurred by molecular weight and steric hindrance of the produced polymers.
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  • Masaya ISHISAKI, Takashi YOSHIMOTO, Masayuki KAWASAKI, Kazuya NANTO
    2014 Volume 51 Issue 3 Pages 191-195
    Published: 2014
    Released on J-STAGE: July 15, 2014
    JOURNAL OPEN ACCESS
    The fountain solution (FS) is one of the important parameters affecting the quality of offset printing. It can be controlled by adjusting the output of the FS motor, but it is quite difficult to measure the amount on the surface of paper, and thus, comparison of the efficiencies of different types of FSs is also difficult to achieve. Therefore, we have developed a quantitative method for determining the amount of FS on a surface by incorporating a fluorescent dye into the FS. There are many problems related to FSs, including greasing, registration errors, and snowflaking. We applied this method to the phenomenon of wet-printing mottle (WPM), which is an uneven print density caused by an excessive amount of FS, to understand the effect of the FS properties. We succeeded in establishing a quantitative method by extracting fluorescent dye from the printed matter and measuring the fluorescent intensity. We confirmed that one of the reasons for the occurrence of WPM was the non-uniformity of water absorption by the paper surface. When less FS was absorbed, the dynamic surface tension and dynamic contact angle of the FS were both smaller, and the WPM was better. We deduced that an effective means of improving the WPM is to use a paper for which there is little unevenness in the water absorption, to use an FS with a low dynamic surface tension, to minimize the amount of FS being used, and to print at low speed.
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