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JAPAN TAPPI JOURNAL Vol.61 No.8

August  2007  Abstracts


Press Section Rebuild and Energy Saving Press Roll

Akimine Izawa and Koshi Tanimoto
Mitsubishi Heavy Industries, Ltd.

  Recently, the attempt to avoid global warming and a sudden rise of the crude oil price push the paper industry to have the ecological effort, such as energy saving, resource saving and high efficiency. Thinking about such a background, MHI has developed compact type of shoe press "Mini shoe press", of which shoe length is 30`40% of STD shoe press and also has developed energy saving press roll, which reduce stirring energy of internal oil.
  This paper presents the feature of Mini shoe press and performance of the first installation in Japan. And also, it presents about the concept and effect of the energy saving press roll.


Voith Paper New Research & Development Center
- Life Cycle Partnership -

Osamu Yasui
Paper Machine Engineering Dept.CVoith IHI Paper Technology Co., Ltd.

  During these few years several new paper machines with high speed and large width started up around the world, and set one speed record after another. Enough pilot machine trials during planning such machines are very important for successful excellent paper quality after start up. Voith Paper new research & development center started in operation accordingly. That pilot paper machine is consist of MasterJet II G type headbox, DuoFormer TQv, Tandem NipcoFlex Press and Top DuoRun, and maximum operating speed is 3000 m/min.
  Here we introduce this sophisticated new research & development center, and we hope this introduction helps for customer to get perfect solution.


Wet End Optimization
- An Ongoing Process with Extensive Benefits -

Roland Berger and Daniel Watzig
BTG Mtek
Kenichi Ishihara
Spectris Co., Ltd. BTG Division

  Gaining greater productivity and paper quality is a systematic and continuous process. This statement is especially true for the Wet End of the paper machine. Many strategic additives are introduced to influence machine runnability and paper quality. At the same time there are only few areas of the paper machine with less automatic control. This paper will present two case studies of waste paper-based newsprint machines at the Papierfabrik Palm, Eltmann mill that led to better control in the Wet End.


The Organic Polymer Coagulant for the Elimination of Pitch Trouble
-Stabilization of Paper Making Process by Inactivating Micro-Pitch Particles-

Kenji Sakai, Takahiro Fujimoto, Hiroyuki Koshio and Motosuke Ono
Shonan Research Center, HYMO Corporation

  In order to eliminate pitch-trouble in paper-making process, use of coagulants is effective to reduce free pitch particles in the process water by fixing "micro-pitch" onto pulp fibers before growing into a large-size pitch.
  In our previous report, we introduced new analysis methods, "micro-pitch image analyzer system" and "film adhesion method", as the tools for analysis of micro-pitches and evaluation of coagulants. The methods showed that a coagulant having specific property reacted with a particular type of pitches selectively, and thus a particular coagulant should be chosen for the different types of furnish, GP, TMP or DIP etc.
  In this report, we indicate several Organic Polymer Coagulants synthesized by controlling the charge density, the molecular weight and the balance of hydrophilic and hydrophobic segments show different characteristics in adsorption onto sticky-pitch, coagulation of micro-pitches and ion-neutralization of anion trash as a pitch control agent.
  We believe that our Organic Polymer Coagulants contribute to stabilize the paper-making process by selecting appropriate coagulant according to the property of the furnish, a type of pitch-trouble or other purposes.


Brightness Reversion of Eucalyptus Pulps after ECF Bleaching with Various Sequences

Christian Blom, Jiri Basta, Magnus Bjorklund, Thomas Greschik and Muneo Sakamoto
Eka Chemicals AB

  The aim of this study was to compare different bleaching alternatives for oxygen delignified eucalyptus aimed at a low brightness reversion. Three eucalyptus pulps with different characteristics were included in the study. D (OP) Dn D, D*(OP) Dn D, A*D (OP) Dn D and Z (OP) Dn D bleaching sequences were compared, and the corresponding sequences with a final P stage instead of a final final D stage were also included. Brightness reversion in both dry and humid conditions before and after beating was evaluated. Other important parameters such as bleaching chemical demand, pulp viscosity and fiber strength potential were also considered.
  When bleaching to 90.5% ISO brightness and compared to the standard D pre-bleaching, D* gave 5-17% savings in OXE, A*D gave 16-24% savings, Z at a high ozone charge (about 5.0 kg/t) gave a small saving (4%) for the traditional E. globulus pulp but increased the OXE consumption with 13-31% for the two other pulps. A considerable increase in chemical demand was recorded at a low ozone charge where also the brightness target was difficult to meet. The standard D sequence gave the highest and the Z sequence the lowest viscosity. The standard D sequence also showed the highest fiber strength potential measured as rewetted zero span strength at 3000 PFI revolutions, and again the Z sequence gave the lowest value.
  The different pre-bleaching alternatives gave only small differences in dry brightness reversion and the results after beating were different from those prior to beating. A final P stage always gave better dry brightness reversion than a final D stage. The standard D sequence gave higher humid brightness reversion values than the other sequences, but modifications to the D sequence showed promising results. Evaluation of brightness reversion in humid and dry atmospheres gave different results and there was no general correlation between the two evaluation methods.

Keywords: oxygen delignified, eucalyptus pulp, bleaching, ECF, chlorine dioxide, hydrogen peroxide,
              ozone, hot D stage, hot acid stage, brightness reversion, beating, fiber strength,
              viscosity, chemical consumption, modified D stages, effluent characteristics


The Anthony-Ross Automatic Spout Cleaner

Ken Pingel and Dan Higgins
Anthony-Ross Company
Trevor Ip
Recovery Process, Northwood Pulp and Paper

  Twelve years ago Anthony-Ross Company applied for and received the patent on our first Automatic Spout Cleaner. Unlike the original however, the Anthony-Ross Spout Cleaner in its current form is a result of over 12-years of design evolution.
  Almost without exception, each of the evolutionary steps from our first spout cleaner to the present was a direct result of observations and suggestions from boiler operators and maintenance staff.
  Twelve years ago the criteria to a functional spout cleaner was unknown, even to boiler operators, but with each new test, test installation and improvement the design was refined and criterion developed until we understood how to produce spout cleaning equipment that would be a true asset to boiler operators without burdening the maintenance staff.
  The following is a description of the Smelt Spout Cleaner in its current form and our patent pending solutions to reliable automatic spout cleaning.


Synergy Effects of PCC and Pigments with High Aspect Ratio

Tatsuya Asano
IMERYS MINERALS JAPAN K.K.
Benny Hallam and Chris Nutbeem
IMERYS Pigments for Paper Europe

  Conventional thinking regarding the optical characteristics for coated paper is the design characteristics of the coating pigments are critical. Key design characteristics are the average particle size, the particle size distribution and the particle shape. If these factors can be combined more effectively in the coated layer they can give improved characteristics, namely, the diffusion of light whereby improving opacity and improving gloss of the coating.
  Optical synergy effects start to become evident through the combination of calcium carbonate and kaolin in which the unique pigment design of each component is different and the result is a complementary effect on coated paper properties.
  Through this research we can understand some of the synergy effects in coated paper when blending coating PCC and high aspect ratio kaolin. The combination of shape engineered pigments leads to synergies that are not evident when simply using size engineered pigments.


Intelligent Sensor Management System
-Capable of Self Diagnostic-

Yasuo Watanabe
Mettler Toledo K.K.

  The periodical maintenance work, for instance cleaning, calibration and so on, is needed to get the accurate and reliable value of the inline pH measurement. In the case of Pulp and Paper industry, many pH loops are working in the factory and a lot of labor power is necessary for implementation of these kinds of maintenance works. And also sometime these maintenance works make the downtime of process. As a result productivity is down. New generation pH electrode which provides not only the saving labor cost, but also reliable pH value was launched by Mettler Toledo. In this report, the features and benefits of the new generation pH electrode are introduced.


Prevention Control of Pest

Yoshihiro Kuroda
Research and Development, Earth Environmental Service Co.

  There are 3 important activities for effective pest control (prevention of insect contamination) in pulp and paper factories as follows;
  1) Analysis of claim from customers caused by contamination of insects as well as detection of contamination in the factory. It is important that they get real-time information of insect (=contaminants) and they should identify the kinds of contaminants, and contaminated location of processing line. Results should also be recorded, collected and kept.
  2) Collecting environmental parameters to use of real time monitoring system indicating direction and velocity of air flow, sheet shutter and doors opened frequency, temperature, humidity for all monitoring points as well as the number of contaminants captured.
  3) Investigation of successive data of each kind of contaminants captured by traps and other environmental parameter in the factory. It is important that they should find out the root of the problem due to correlation analysis.


Trend in Mechanical Seal Technology in Pulp and Paper Plant and Erosion Countermeasure Examples of Mechanical Seal

Hidekazu Takahashi
EAGLE INDUSTRY Co., Ltd., Seal Engineering Dept.

  In a pulp and paper plant, a large number of water pumps and various different pumps for pulp or chemicals are utilized in the production processes from economical point of view (energy saving, resource saving and maintenance saving) and environment preservation point of view. Mechanical Seals are also utilized for other rotating equipment including agitators, screens and refineries. The Mechanical Seals for pulping is especially important. These sometimes leak by the damages of the Seal Rings and the Mechanical Seal Covers by the sand erosion. This text describes failure and countermeasure examples of Mechanical Seal for pulping process.


Effect of Surface Structure on Gloss of Coated Paper

Hideyuki Mikado, Keiro Takigawa, Yukiko Suzuki and Tetsuya Hirabayashi
Pulp & Paper Research Lab., Oji Paper Co., Ltd.

  Gloss of coated paper is affected by the surface shape and scattering intensity of pigment layer. The surface shape consists of various micro-plane slopes. Each degree of micro-plane slope is estimated by the differential value of curved surface. Scattering intensity of pigment layer is estimated by the pigment diameter. In this paper, we investigated surface structure of coated papers which had various degrees of surface smoothness in order to clarify the dominant factor of gloss of coated paper.
  We found that there was a good correlation between degrees of print gloss and differential values of printed surface. This means that print gloss is dominated by the variety of micro-plane slopes forming the printed surface shape. We also found that there was a good correlation between degrees of differential values of printed surface and degrees of differential values of@unprinted surface.@This means that the printed surface shape mainly depends on the surface shape before printing.
  Ink layer gives various affections to the surface shape of printed paper. In regard to gloss paper including LWC, the ink layer reduces the differential value of curved surface. The matte paper has no effect on that of curved surface. The cast-coated paper is affected increasing the differential value of curved surface. Therefore, as the paper surface becomes much smoother before printing, such as cast-coated paper, the printed surface shape has much stronger influence of ink layer.
  We also found that sheet gloss was decided by differential values of the surface shape and the diameter of pigment constituting coated layer. Therefore, we assume that sheet gloss is dominated by the variety of micro-plane slopes on the paper surface and scattering intensity of pigment in the coated layer.

Keywords: coated paper, print gloss, sheet gloss, micro-plane slope, differential value, scattering,
              pigment diameter, coated layer, ink layer