Journal of Printing Science and Technology
Online ISSN : 1882-4935
Print ISSN : 0914-3319
ISSN-L : 0914-3319
Volume 26, Issue 5
Displaying 1-6 of 6 articles from this issue
  • Parameters and Methods
    1989 Volume 26 Issue 5 Pages 226-244
    Published: September 30, 1989
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    A sub-group in technical committee of Japanese Society of Printing Science and Technology have surveyed the parameters deciding the quality of the color printed products by off-set press and methods for measuring and controlling it in the process. The survey are made over whole printing process which are consist of pre-press, plate-making, proofing, and press. In pre-press including color separation process, the relation between mental and physical parameters play main rule, although physical parameters are mainly considered in succesive process.
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  • Determination by Refractive Index
    Shinichi TOZAWA, Shigeru WATANABE
    1989 Volume 26 Issue 5 Pages 245-250
    Published: September 30, 1989
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    In lithographic printing, it is well known to apply a specific gravity (S. G.) for the measurement of the amount of isopropyl alcohol (IPA) in the fountain solution. The fountain solution usually contains a small amount of desensitizer with IPA. As a S. G. greatly depends on temperature it is difficult to determine the accurate amount of IPA. Some unavoidable errors occur during the S. G. measurement, caused by ink scum, dust and bubble. We studied many methods for the accurate measurement of IPA concentration in the fountain solution: S. G., pH value, electric conductivity and refractive index (Brix%). As a result, we found that Brix% is the best way to measure an accurate amount of IPA, independent of a small amount of desensitizer.
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  • Yi JIANG, Takeshi AMARI, Koichiro WATANABE
    1989 Volume 26 Issue 5 Pages 251-257
    Published: September 30, 1989
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    Ink penetration is of great importance in printing processes. Especialy, an initial setting of printing ink is greatly influenced by the ink penetration which depends on the porosity of a printing paper. In order to investigate the ink penetration accurately, we developed a measuring system of the ink penetration depth using a CCD video camera and an image processing board (Photron FDM 98-4). The ink penetration depth was determined from the reflection density of the reverse side of the printing paper. Suspensions of carbon black in linseed oil at various concentrations were used as sample inks and the penetration behavior of these suspensions into wood free paper and coated paper was observed. The phenomenon of ink penetration can be predicted by Lucas-Washburn's equation; the penetration depth increases in proportion to square root of elapsed time and mean radius of pores in a paper stock. The ink penetration speed in the coated paper is not so fast and not influenced by a consistency of ink which depends on the volume fraction of pigment. The reason for this phenomenon is explained as follows. The pore structure in the coating layer is different from that in the body stock and pore size of the former is extremely small. The pigment particles and/or flocs formed by them lerger than the pore size of the coating layer may be filtered. The measurement of the time dependence of the penetration depth is an effective method to investigate the interconnected fiber structure in paper stocks. We can also evaluate the ink-setting characteristics from the dependence of the penetration depth on time.
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  • Wladyslaw SKARBEK
    1989 Volume 26 Issue 5 Pages 258-264
    Published: September 30, 1989
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    Practical algorithms for octree construction for 3D images are developed. They are based on Hilbert scan of 3D image space. Their implementations are short and efficient. Two kinds of octree representation are considered: linked tree structure and linear octree. Two models of input image are discussed: 3D raster image array, and large volume data.
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  • Basic Course (5) Color Difference
    Toshio ICHIMI
    1989 Volume 26 Issue 5 Pages 265-273
    Published: September 30, 1989
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    The color difference ΔE is expressed as the distance of two colors in the three dimentional color spaces. Many color scholars has devised UCS diagrams and color difference formulae to calculate ΔE. UCS (Uniform-Chromaticity Scale) is such a diagram; the chromaticity coordinate values of the Munsell Color Swatches are plotted with equal interval spaces. Four formulae are now used by the Japanese Industrial Standards: (1) the CIE-1976 L*a*b*, (2) the CIE-1976 L*u*v*, (3) the Adams-Nickerson's and (4) the Hunter's.
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  • Miharu TANAKA
    1989 Volume 26 Issue 5 Pages 274-277
    Published: September 30, 1989
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
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