2002 Sep JAPAN TAPPI JOURNAL

 

JAPAN TAPPI JOURNALVol. 56, No. 9

September 2002 Abstracts


Sheet Formation Technology on Roll-Blade Former
Hiroshi Iwata and Kazuhiko Masuda
Mitsubishi Heavy Industries, Ltd., Hiroshima R&D Division
Masanobu Matsumoto
Mitsubishi Heavy Industries, Ltd., Paper& Printing Machinery Division

 The purposes of newly developing for MJ series paper machine are to accomplish higher production and operator-friendly operation at 2000 mpm.
 Since the forming section requires stable sheet forming and good quality of paper on high-speed operation, a suction forming roll at initial drainage zone and the wedge-shape blade was opposing counter blade at mid-mat forming zone are incorporated in MJ former.
 And today, we are able to propose blade former or roll-blade former according to user needs.
 In this paper, we present the results of drainage element studies and pilot machine trials.


The newest high-speed board paper machine−Top Quality at Top Speed−
Kousuke Tano
Machinery group, Paper machinery division, Sumitomo Heavy Industries, Ltd.

 Even though targeted speeds are approaching each other on printing paper and board machines, there are many distinct differences in the machine lines.
 Two Former achieved essential strength properties for board paper.
 Closed transfer without the center roll is more important with low quality waste paper than with virgin pulp.
 Surface sizing of boards is different from fine paper. The need to achieve full penetration is essential. Full penetration means weaker runnability properties.
 The TurnDry contactless dryer is a great tool in this respect.
 Final dryness is reached by two tier felting in order to control the curl of the web.
 All these sections and components within each section makes a line ? Opti Concept line for Boards at high speed.


How to Fulfill the New Requirements of the Wet End Process?
Bernhard Mu(・・)ller1,Masakazu Eguchi and Jun Eguchi
Engineering & Development Division, Voith IHI Paper technology Co., Ltd.

 The future generation of paper machines will be characterized by increased operating speeds and at the same time higher product quality demands, including machine directional (MD) and cross machine directional (CD) profile stability.
 To meet these new requirements, the wet end process (WEP?) around the wet end of the paper machine needs to be redesigned. New machines and tools are presented here for mixing the stock and filler components, for white water dilution, stock cleaning and deaeration, adding of retention agents and for the entire white water handling.
 The overall goal is to optimize the entire WEP? for more profitable operation.


Advanced Wet-end Concepts to Stabilize Paper Machine Running
Roland Berger, Lydia Bley and Rainer Rauch
MUETEK Analytic GmbH

 Over ten years of experience with on-line charge demand analysis has shown that measurements conducted in white water frequently fail to produce meaningful results. One reason, among others, is that white water contains different charge carriers, such as fines, fillers and colloidally dissolved anionic material. In addition, charge carriers that are neutralized upstream from the white water basin escape detection at this particular sampling point. In view of the ongoing trend towards more complex retention aid systems and the increased use of recovered waste paper furnishes, charge measurements in white water are losing importance. Instead, on-line charge measurements should be performed at the source of anionic trash, for example coated broke, TMP or DIP. Another likely measuring point is after the addition of a chemical aid into the thick or thin consistency stock.


BTF Headbox System A New Dilution Control System for Existing Headbox
Hiroshi Takahashi
Design Sec. ,Kawanoe Zoki CO.,Ltd

 The demand for improved paper quality is requiring mills to produce paper with less variation in basis weight profile and improved fiber orientation uniformity.
 Conventional headbox profile control by slice bending is limited in its ability to meet these demands. Mechanical restrictions limit the precision of the basis weight profile control, and slice bending causes changes in the local flow rate, jet velocity and direction resulting in non-uniform cross machine fiver orientation.
 Dilution control systems are therefore becoming more common as a replacement for conventional slice lip control. These systems can provide better CD basis weight control without interaction with fiber orientation.


Latest on-line calender technology Janus MK2 calender
Eiji Ando
Engineering dept.,Voith IHI Paper technology Co., Ltd.

 Market demands to improve the paper quality and production efficiency, however, off line supercalender is available for highly compressed paper applications, i.e. A1, A2 coated paper and / or SC paper, etc. The supercalenders are becoming bottleneck. Voith Paper developed the Janus calender focusing on-line installation in 1996, it is now improved as Janus "MK2" with state of the art. Following provides an introduction of the Janus MK2. The technical and technological possibilities of this Janus "second generation" to be installed online are presented.


Development of Mitsubishi High-Speed Film Coater
Masahiro Sugihara and Kenji Yamada
Mitsubishi Heavy Industries, LTD. Hiroshima R&D Center
Hiroshi Miura and Toshiaki Miyakura
Mitsubishi Heavy Industries, LTD. Paper & Printing Machinery Division

 Mitsubishi High-Speed Film Coater (MJ Film Coater) has been developed as the on-machine film coater and size press for our newly developed high-speed papermaking machine (MJ series). In this development, we mainly focused on the reduction of "misting" which occurs at the outlet of applicator roll nip in high-speed coating. Non-dimensional characteristics of misting phenomena have been got in this investigation. According to the results, the state of the art "Continuous Contact Length Control System" and "Low-Adhesive Applicator", which realize the reduction of misting in high-speed coating, have been developed. In this paper, we report the results of fundamental studies and the outline of our new film coating technologies briefly.


The coating application using the Excellent Flow Modeling Software FLOW-3DR
yoshihiro Miyamoto

 FLOW-3DR is a unique computational fluid dynamic program that was developed by flow science inc. in us. FLOW-3DR has a full navier-stokes solver based on the fAVORR (fractional area volume of obstacle representation) finite difference scheme. the true vof (volume of fluid) algorithm is incorporated into FLOW-3DR that provides the reliable free surface flow analysis. FLOW-3DR has a variety of physical models. therefore FLOW-3DR is used in the wide range of industrial area including the inkjet or the coating. in this paper the feature of FLOW-3DR and the direct computation of dynamic contact lines, the application examples for the coating are described.


Tesa EasySplice FastLine
New Flying Splicing Tape Technology for Improved Productivity
Bernhard Gebbeken Dr.-Ing.
Tesa AG
Kashiwabara Yuki and Mukasa Munetaka
Tesatape k.k.

 Tesa EasySplice, a new flying splice tape technology for straight line splicing in paper production is introduced. The tape design and function will be explained. In the next step various methods for splice preparation will be presented. Process improvements for offline coaters are: no air pockets during acceleration of the new jumbo roll, no wet areas after coating, less tape and no labels. This means increased productivity for the paper manufacturer due to higher splice security, faster splice preparation, higher splicing speed. Experiences by european customers and their product evaluation will be shown. Also experiences by a machine manufacturer is presented. An outlook is given to the application of flying splice at offline calenders.


Application of New Evaluation Method of Sheet Appearance to Various Coated Papers
Kasuke Fujita, Nobuhiro Matsuda, Hisashi Matsui and Yoshiaki Zama
Polymer Research Laboratories, JSR Corporation

 Coated paper is required to have excellent sheet appearance. And it is well known that sheet appearance is affected by gross profile. Evaluation of sheet appearance is generally determined by visual inspection. However the evaluation method is subjective and not quantitative, so that the evaluation of sheet appearance is too difficult. For purpose of quantitative evaluation of sheet appearance, a few methods have been reported.
 We reported that we developed a new evaluation method of sheet appearance of coated paper with using Scanning White-Light Interferometer(ZYGO New View system). And we found that the standard deviation of average of surface slope angles(ASSA) was strongly related to sheet appearance. That is, we can conclude that the more distribution of ASSA becomes uniform, the more sheet appearance becomes better.
 In this paper, we measured distribution of ultra fine surface profile of various commercial coated papers, and studied influence of the standard deviation of ASSA to sheet appearance.
 As a result, we found that the optimal threshold of ASSA at binarization changes with kinds of coated papers and optimal threshold is ±7°for A2 coated paper or ±10°for A3 coated paper. We also found that correlation with sheet appearance is the best, when it is not concerned with the kind of coated papers but the slope angle area ratio(SAAR) at binarization becomes 70%.

Keywords: Sheet Appearance, Coated Paper, Surface Profile, Standard Deviation,Scanning White-Light Interferometer, Surface Slope Angle, Binarization


Reports of 2002 International Pulp Bleaching Conference
Takanori Miyanishi, Ph.D.
Pulp and Paper Research Laboratory of Nippon Paper Industries Co., Ltd.

 A historical and technological review of the 17 International Pulp Bleaching Conferences from 1955 to 2002 confirms that the pre-eminent bleaching conference is indeed international. About half the papers had overseas authors. The "Big Four" countries Canada, USA, Sweden, and Finland dominate, but other countries, such as Brazil, have recently increased their share of papers considerably. The most recent bleaching technology milestones to be implemented in industrial operations are ozone bleaching and acid hydrolysis removal of hexenuronic acid.

Keywords: bleaching, ECF, mill closure, ozone, hexenuronic acid


Environmental Evaluation on Melting Treatment of Paper Products
Katsuhito Nakazawa
Japan Science and Technology Corporation
Keiichi Katayama
Graduate School of Engineering, Tokai University
Hidetoshi Miyazaki
Satellite Venture Business Laboratory, Shizuoka University
Hiroyasu Sakamura and Itaru Yasui
Institute of Industrial Science, University of Tokyo

 At present, there are some environmental problems such as an increase in the domestic waste and a shortage of landfill site in Japan. Especially, the amount of paper products (newspaper, photocopy paper, corrugated board, weekly magazine, gravure magazine, catalog, etc.) accounting for more than 50% of all domestic waste has been increasing. Therefore, the reduction of its incineration ash becomes a pressing task for using the landfill site as long as possible. In this study, the effect of melting treatment on the reduction of paper products was investigated, and the amounts of chlorine in combustion gas and in residual ash generated from each paper product were evaluated.
 The melting treatment was found to reduce effectively the amount of paper products, and therefore to be effective for prolonging period of landfill site in Japan. The chemical composition of the slag prepared by melting paper products was mainly composed of several compounds in the SiO2-Al2O3-CaO system, and the slag was suitable for preparing various glasses. Furthermore, the melting temperature decreased in increasing amounts of glass cullet that was mixed with combustion ash. The amounts of Pb and Sb eluted from the molten slag in pure water, salt solution (3.5wt%) and acid solution (pH3) were much lower than those from the combustion ash. In addition, the chloride gas and chloride compounds in residual ash generated from the combustion of paper products were scarcely detected. These results suggested that the amount of toxic chlorine emitted by melting paper products is extremely small.

Keywords:Paper products, Melting treatment, Molten slag, Residual ash, Chlorine


Dioxins Levels in Chlorine Dioxide Bleaching of Hardwood Oxygen-bleached Kraft Pulp (II)
Levels before and after Mill Operation of Chlorine Dioxide Bleaching
Hiroshi Ohi
Institute of Agricultural and Forest Engineering, University of Tsukuba,

 Some results of the plant-effluents from chlorine pulp bleaching mills showed the total TEQs are less than the effluent standard: the permissible limit for specified facilities(10pg-TEQ/L), but more than the environmental standard for public water(1pg-TEQ/L). The TEQs of 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDD are partly responsible for surpassing it. The origin of the HxCDDs in the effluents is thought to be the TeCDD in an agrochemical, but not to be lignin.
 In Japan, CNP (chloronitrofen: an agrochemical made from chlorinated phenols) had been scattered in paddy fields as a herbicide. It has been clarified that CNP includes 1,3,6,8-TeCDD, 1,3,7,9-TeCDD and 2,4,6,8-TeCDF. It was found in some results of analysis that concentrations of 1,3,6,8- and 1,3,7,9-TeCDDs in effluents from kraft pulp bleaching plants are relatively high, for example, 100pg/L for 1,3,6,8-TeCDD. The toxicity equivalency factors (TEFs) for 1,3,6,8- and 1,3,7,9-TeCDD are not defined yet by WHO1998, and then their concentrations do not consist of the total toxicity equivalency quantity (Total TEQ). However, the TEFs for 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDDs are defined as 0.1. Therefore, the total TEQ of the effluent may increase if the HxCDDs form from the TeCDDs by chlorination.
 Some results of the plant-effluents from ECF (chlorine dioxide) pulp bleaching mills showed the total TEQs are lower than the environmental standard (1pg-TEQ/L). It was found in some results of analysis that concentrations of 1,3,6,8- and 1,3,7,9-TeCDDs in effluents from kraft ECF pulp beaching plants are relatively high, for example, 440pg/L for 1,3,6,8-TeCDD, which should be impurities in the CNP. Laboratory bleaching using a mill LOKP and chlorine dioxide in the range of KF:0.14-KF:1.14 have shown that 2,3,7,8-TeCDD and TeCDF are not detected. It is considered that water qualities of process sewers in ECF pulp bleaching mills should be less than the environmental water quality (1pg-TEQ/L).

Keywords: Dioxins, Pulp Bleaching, Chlorination, Agrochemicals, Chlorine dioxide, Herbicide, Chloronitrofen,1,3,6,8-Tetrachlorodibenzo-p-dioxin, ,2,3,6,7,8-Hexachlorodibenzo-p-dioxin