[in Japanese]

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Wet web strength properties are presented up to 60°C in the range of 30% to 50% solids content for three furnishes, one newsprint, one unbleached and one bleached softwood kraft at several levels of refining. They refer to MD stress-strain measurements in a cabinet supplied with saturated water vapour of the desired temperature on oriented laboratory sheets pressed in static or dynamic nips with subsequent partial drying. They cover the tensile strength, the breaking elongation, the modulus (or tensile stiffness index) and the rupture energy absorption. They also are presented as a rupture envelope.
At solids contents of 40% to 50% the drop in tensile strength with increasing temperature is about 1% per °C. This relative drop in strength is characteristic for paper webs above the glass transition of their cellulose and hemicellulose polymers. It is larger than that for water-free, sheets below their glass-transition temperature and is interpreted as a reduction in the inter-polymer and inter-fiber hydrogen bond strength. At solids contents below and around 30% the drop in tensile strength with increasing temperature is much less and in proportion to the surface tension forces which there dominate interfiber bonding.
In an open draw sensitive to web breakage an increasing wet web temperature thus has to be compensated for, e. g. by increasing solids content.

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Hachinohe's latest machine No. 6 PM started it's operation at 1990. On this new PM, BELRUN Dryer has been introduced entire main dryer bank.
At the early stages we had been suffered by wrinkles and this was overcomed by draw, drying survey and vacuum of BELRUN Roll control.
Now, draw of the main dryer is small as is expected, and shrinkage is reduced to half compared with that of machines. As the result of drying under strain the smoothness near the edges and the CD hydroexpansivity are improved.

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The Kasugai Mill constantly upgrades its equipment and computer-controlled technology to ensure the high quality and stable supply of its products. The history of the computer control has been applied since in 1969.
We have now 10 Computer Systems, 8 DCS and a PC-LAN System. Although Pulping and Boiler process is already well managed with combination by process computers and DCSs, automation of finishing process is a subject which we must develop further.
We installed highly integrated production system in finishing process with Fujitsu A 600 computer in 1991.
This report introduces many kind of automation technology.

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[in Japanese]

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[in Japanese]

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The waste paper as raw materials for paper has generally extremely wide fiber length spectrum, and it is desirable to process it selectively for long and short fibers. The fractionating equipment available today to achieve this are screens with variety of concepts. The tendency in application of such technology in Europe is described herein, with comparison of hole and slot screens as well as comparison of selective partial flow treatment and full flow processing.

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This work is aims at visualization of the local surface deformation behavior of paper sheet under tensile stress by non-contact means.
The interference holography-based moire fringe pattern strain measurement system was utilized for the analysis of the local strain distribution of paper surface.
Since it was suggested in the previous study that the moire fringe pattern changes with the type of deformation, that is, elastic deformation or plastic deformation it was intended to compare the moire fringe pattern of different level of deformation of tensile testing process.
The following is the summary of the results obtained by in this work.
(1) Interference holography measuring system is permits visualization of continuous local microscopic deformation change of paper sheets.
(2) From the analysis of strain distribution of paper sheet under tensile stress, it was suggested that the elastic deformation occurs at the initial stage of deformation and as the deformation proceeds, the plastic deformation starts to come into play.

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Recently, the use of corrugated fiberboard as a packaging structural materials has been increased, and it has been required to have high-precision and high-strength as industrial materials. Corrugated fiberboard is composed of the paper board (corrugated fiberboard stencil) of top liner, bottom liner and medium. It is well-known that the paper board expands and shrinks easily, because the shape change as the moist-expansivity, shrinkage of fibers occurs through the temperature and humidity change. The Young's modulus and expansivity of paper board depend upon the papermaking machine direction (MD), because fibers of the paper board manufactured by a paper-making machine arrange to the paper-making direction. Furthermore the direction was arranged fibers (a fiber orientation) does not always match the paper-making machine direction. In this study, A nonlinear and continuous mechanical model developed for superplastic materials was proposed to analyze the tensile and the bending properties of fiberboard before/after the temperature and humidity cycling. For the warping deformation problem of corrugated fiberboard, a prediction equation of warping deformation was derived from the Lamination theory, and the mechanism of the warping deformations were investigated. Following results are obtained : (1) The nonlinear and continuous mechanical model can be applied to the analysis of the tensile and the bending properties of fiberboard. (2) For SCM, the creep rate in the fiber direction (MD) decreases about 4% by temperature and humidity cycling. (3) Spring backs of fiberboard increase by the temperature and humidity cycling, and increasing rate by the humidity cycling is greater than by the temperature cycling. And further, increasing rate of CD is greater than MD. (4) Generation limits of spring back of KL and SCM are set within the limits of a finite band by the temperature and humidity cycling. (5) There is little change in the residual stress distributions of the sheet for KL, but residual stress for SCM increases by temperature and humidity cycling. (6) Relation between the warping and the parameter influenced the warping has been elucidated by the simplified prediction equation, and prediction of the warping deformation are possible by them. (7) The twisting warping are closely connected with difference of the fiber orientation angle between top liner and bottom liner, and they increase with fiber orientation angle. (8) The bending warping and twisting warping increase as the anisotropy ratio of Young's modulus and the anisotropy ratio of the expansivity, and the increase ratio of bending warping along with the machine direction (MD) is larger than it along with the cross direction (CD).

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