2003 Dec JAPAN TAPPI JOURNAL

 

JAPAN TAPPI JOURNALVol. 57, No.12

December 2003 Abstracts


Current state and the Future of Recovered Paper in Japan
Haruo Takayanagi
Paper Recycling Promotion Center

 The Japanese paper industry has accomplished development until today owing to the effective use of the recovered paper as the paper manufacture raw material and the technological development on paper recycling in Japan where resource is scarce.
 The recovered paper urination rate is 59.6% in 2002 now. It is about twice of the urination rate 30% in the paper manufacture raw materials 40 years ago.
 We come to the one more push to reach the target of the reutilization rate 60% in fiscal year 2005.
 In several years especially, the recovery rate and the utilization rate is rising remarkably in Japan. It is in the background that the improvement of national consideration has been advanced because of promotion of the decrease in weight of garbage and the introduction of the green purchase, etc. aiming to construct the recycle base society. Moreover, the advancement of the recovered paper use technology cannot be missed.
 On the other hand, China and Asian nations increase rapidly the import of the recovered paper from Japan along with the increase of the production of paper and the paperboard in the countries. Now, recovered paper is an international global trade raw material.
 I had groped for the view in the future of the recovered paper use in Japan based on such a current state including the energy in the future and environmental problems such as the CO2 reductions.


The Latest Refining Technology‐Low and High Consistency Refiner Coordinated with Stock Refining Characteristics‐
Kazuo Aoshima
Technical & Engineering Dept., Aikawa Iron Works Co., Ltd.

 Recently the environment around papermaking industry becomes increasingly severe. Strict conditions are placed especially on CO2 reduction, stock cost saving, energy cost saving, etc. Therefore also in stock preparation department we are forced to address these problems recently. What we should consider initially is energy saving of machinery consumes big energy. In that respect low consistency refiner especially needs to be considered most of all. However the energy saving also can be the factor affects quality and we cannot change it easily. So, I will introduce the new refiners as well as the result of consideration for low consistency refiners have been practiced lately this time.
 In the case of waste paper handling, it will greatly contributes to cost saving to consider how to produce higher quality by handling the cheapest possible waste paper. On the same time, considering the measures against reduced paper intensity due to the increase of recycling, high consistency refining draws attention as refining produces paper intensity using cheap stock. So, I will also introduce the latest machinery for high consistency refining and the result.


A New Screening Concept and the Latest Mill Application in Thick Stock Screening
R. Rakohnen
Andolitz OY
Yosuke Takeshita and Hiroyuki Nagasawa
Andolitz K. K.

 The main demands for paper and board production are the cleanliness of the end product and run ability of the machine. Therefore the stock fed into the machine is cleaned in several position before it enters the headbox. The expectations for the stock cleanliness are putting the equipment manufacturers to face a very demanding and challenging task. A new method to increase the cleanliness of the stock is the socalled thick stock screening, where the stock is screened with narrow slots before it enters the short circulation.


The Highest Potentiality and Efficiency of Algas Microfilter-The Reference Report from Japanese Market-
Yasuo Harikae
Itochu Sanki Corporation

 In compliance with social requirements on environmental protection, pollution control for water at a pulp and paper mill is becoming more and more important. Also, water consumption need to be decreased in light of material resource saving as well as production cost saving.
 Under the circumstance, not less than 500 Algas Micro-Filters (AMF) are running all over the world and we have installed 18 AMF in Japan since 1998. AMF can contribute to re-use fibers, clear water and additives from white water, effluent water etc. and to reduce cost of water treatment as well as water discharge.
 This report is to explain the basic construction and features of AMF and the successful references of AMF installation in Japan.


Technical Trends for Stock Preparation Equipments
Toshikazu Miura
Paper machine designing section, Mitsubishi Heavy Industries, Ltd.

 In the view point of the stock preparation equipment which gives the gentleness for global environment, the first principle is less energy consumption on the basis of KW.D/T. And the society switches over resources sustainable circulation system so as to recycle the all things come to an end. On these situation, up to this time, the hard-repulping papers were disposed to land reclamation and/or to burn it to ashes by mean of the cost balances with spending much more money for recycling works.
 But at now it becomes a required subject to recycle the hard-repulping papers and change to new resources.
Fortunately we have ever supplied "BR PULPER" (old name is BARRACUDA PULPER) as to treat efficiently the hard-repulping paper.
 The required repulping energy for treatment of the hard-repulping papers spends five to ten times as compare with the normal pulp and papers.
 Then we developed new pulper for the purpose of treating the hard-repulping papers with less energy.
 We call this new pulper "MJ PULPER".
 On the other hand, on going with recycling old papers, the screening equipment is the most important device to reject foreign materials except fibers from old paper stock. Then we conducted research and development new screen having the capacity two times higher compare with existing one.
 We call this new screen "MJ SCREEN".
 In the below, we will introduce the outline of MJ PULPER and MJ SCREEN.


POM System- Centrifugal Degassing and a Closed Hydraulic Wet End System Give Expected and Less Expected Benefits -
P. O. Meinander
POM Technology
Joji Taketomi
Matsubo Corporation

 The compact POM System was originally developed In order to obtain a more responsive system, allowing easy grade changes. With the experience of twenty references we have learnt that it also gives many other benefits, among these some quite unexpected ones. The most unexpected is improved process stability compared to that of a traditional system. Others are superior system and product cleanliness, easy handling, reduced energy consumption, better formation, and sheet bonding, less web breaks, less additive consumption, less fiber losses and finally a system simplification yielding a cheaper system and requiring less space.


Advanced Stock Preparation and Wet End Process
Junichi Miura
Stock Preparation Group, Application Engineering Dept.,
Voith IHI Paper Technology Co., Ltd.

 In recent years, the situation surrounds the paper mills have increased significantly. Zero emission - such as water saving and industrial waste reduction ? become the universal factor.
 Beyond that, the stability of the paper machine and the CD and MD profile of the paper have to be simultaneously improved.
 We have to think about one common process. This means that stock preparation, white water circuit, effluent treatment, reject handling, chemistry and last but not least the wet end process have to match perfectly together.
 This paper introduces the latest DIP and wet end process for graphic paper in Europe.


OptiFeed ? New Stock Preparation and Approach System
Akifumi Hatta
Metso-SHI Co., Ltd.
Jussi Ahola
Metso Paper Valkeakoski Oy

 Increased stock quality and efficiency of the stock preparation process are the main focuses of the OptiFeed concept. A conventional stock preparation system, including approach system, has some major problems, such as uncontrollability of consistency of each furnish and large dead volume in tanks. Immediate problems with such systems are stability, such as consistency swing, and the extended time required for grade changes.
 Through applying the new process solutions, equipment and automation within the OptiFeed concept, uniform stock parameters such as consistency and pressure of furnish fed to the paper machine can be achieved. At the same time, faster grade change time can be obtained which also results in better efficiency. In addition, less space and energy is required, which reduces investment and operation costs.
 In addition to several partial OptiFeed system is operation, the first full-scope references have been successfully started up. Those OptiFeed systems are discussed in this paper, including the first mill results and experiences.


Optimized Deaeration Leads to Substantial Process and Quality Improvements in Paper Manufacturing
Rainer Rauch
BTG Muetek GmbH
Kenichi Ishihara
Spectris Co., LTD. BTG division

 High air or gas contents in pulp suspensions constitute a serious problem area in papermaking. They are responsible for higher pump energy demand, deposits, pinholes, foaming and several other problems. An underestimated source of these problems is dissolved gases. High contents of dissolved gases mainly originate from a decomposition of calcium carbonate where carbon dioxide is formed. In comparison to air and its components, carbon dioxide is far more easily dissolved in water. The immense pressure drop at the wire and at the foils leads to dissolved gases being released. The measurement results achieved in various mills show that determining the levels of entrained and dissolved gases online enables the optimization of prevention measures as well as mechanical and chemical deaeration. The results also show that online control of deaerator chemicals based on the measurement values leads to substantial costreductions, process improvements and quality enhancements in paper manufacturing.


Features from Complete Plant Reference
Andreas Sauer
Voith IHI Paper Technology Co., Ltd.

 Voith Paper’s proven technology and experience has made it today a future-oriented company providing the complete spectrum of technology. Since 1841, we have proven our competence to over 4000 customers worldwide. In the last six years alone, our engineers have planned 31 stock preparation plants, 24 paper machines and 13 complete plants. The constant exchange of experience between the worldwide Voith Paper Group companies ensures multiple synergy advantage.
 The experiences with the TwinDrum Pulper showed that for Graphic Papers the chemical consumption is much lower than with high consistency pulpers. For Board and Packaging one customer does not even have to use his disperger for some grades. The flake content after the Drum is as low as in other applications it is reached after hole screening. Ecomizer Cleaners with their new technology can now be placed before the flotation and save therefore money for wear parts. New ideas about screening have proven their reliability and helped to increase the runability of the Papermachine. The latest virgin fiber pulper and refiners have helped our customer to get the maximum out of their furnish.
 In China, Voith will start this year five new Papermachines (Huatai, Shandong Bohui, Jinfeng, Hengfeng, Mingfeng). All off them have chosen Voith as their main supplier for the total plant. Our service centres in Kunshan and Dongying, our technology managers and of course our staff at Voith Paper China RO in Shanghai are helping them for the entire life cycle of their plant.


The Structural Characteristics of High Molecular Weight Chlorolignin Produced by Chlorine Bleaching of Kraft Pulps
Hiroyuki Shintani, Yuji Matsumoto and Gyosuke Meshitsuka
Laboratory of Wood Chemistry, Department of Biomaterial Sciences,Graduate School of Agricultural and Life Sciences, The University of Tokyo

 Three types of kraft pulps (unbleached softwood, unbleached hardwood and oxygen prebleached hardwood kraft pulps) were chlorinated at various levels of chlorine ratio (0.1-0.3), and residual chloroorganics in pulps were extracted in high yields by aqueous dioxane. Neutral sugar contents of these extracts were in the range of 1 to 5%. Extracted chloroorganics were treated by aqueous alkali in a similar condition as the E1-stage of bleaching. Structural features of extracted chloroorganics and their alkali-treated products were analyzed by 1H-NMR spectroscopy, FT-IR spectroscopy and others. These results revealed that the structures of chloroorganics were quite different from that of native lignin. Only few aromatic protons are observed in 1H-NMR spectra. Instead of this, chloroorganics are very rich in methyl, methylene and methine structures and carboxylic acids. Model experiments using milled wood lignin (MWL) revealed that these structural features can be reasonably explained by the structural modification, especially by an oxidative ring opening, of residual lignins in unbleached kraft pulps during chlorine treatment.

Keywords: kraft pulp, chlorine bleaching, lignin, chloroorganics, 1H-NMR, FT-IR


The Synthesis of Zeolite from Paper Sludge (PS) Associated with Its Carbonization
Takao Ando, Masato Saito, Shigeo Muramatsu and Kimio Hiyoshi
Fuji industrial research institute of Shizuoka prefecture
Junsuke Haruna, Naoto Matsue and Teruo Henmi
Department of agriculture, Ehime Univ.

 Paper sludge (PS) discharged from the paper recycling process is one of the wastes requiring active development of novel technology for their complete recycling. The PS is mainly consists of organic (cellulose) and inorganic (calcite, talc, kaolinite) matters which are originally present in paper. The present study has been concerned with reaction conditions such as reaction time, solid/liquid ratio and NaOH concentration for the synthesis of zeolite from the inorganic matters by successive alkali treatment following carbonization of the organic matters, intending to develop a new use of PS. Chemical and mineralogical characteristics of the synthesized zeolite were investigated, and the results are as follows:
(1) It is ascribable to decomposition of calcite scarcely occurred in the processing carbonization due to a high partial pressure of CO2. Therefore, carbonization process is found to be effective for the synthesis of zeolite from the PS.
(2) Carbonized matter in PS was activated in the alkaline treatment. The metakaolinite in carbonized PS was converted to zeolite faster than pure metakaolinite alone by the alkaline treatment. The zeolite formed in carbonized PS, showed fine grain in crystal morphology. We found that careful control of solid/liquid ratio, NaOH concentration and reaction time in the alkali treatment process for carbonized PS could give a new composite material of active carbon and zeolite.

Keywords: paper sludge, kaolinite, zeolite A, coal, active carbon