Vol.68, No.4 Abstracts

Operating Experience of Dissolving Kraft Pulp

Yoshifumi Horisaki
Kushiro Mill, Nippon Paper Industries Co., Ltd.
Current Affiliation : Maryvale Mill, Australian Paper Pty Ltd.

  In recent years, the demand of rayon for clothing and woven is growing based on the background to the remarkable economic development at Asian region, especially China. The raw material of rayon is cotton linter or dissolving pulp. Dissolving pulp supply can be stable because dissolving pulp is industrially produced without climate affects which cotton linter always faces on. So the stable demand of dissolving pulp is expected in the future.
  Dissolving pulp has been produced by the Sulfite Pulp method. However, manufacturing techniques to produce dissolving pulp by the Kraft Pulp method with continuous digester has been developed. Kushiro Mill, Nippon Paper Industries Co., LTD., started up the world first continuous cooking process for softwood Dissolving Kraft Pulp (DKP) in 2012, and started commercial production in March, 2013.
  This report covers the installation of DKP process and experience of DKP operation.

Operating Experience of Canvas Cleaning Equipment

Kanichiro Kadoya
Kushiro Mill,Oji Materia Co.,Ltd.

  Oji Materia Kushiro L-1 produces linerboard 1,370 ton per day. It is one of the largest linerboard machines in Japan. The paperboard comprises three layers; bottom layer is formed by Fourdrinier, middle and surface layers are done by Belbond-former.
  We take a variety of measures against defects derived form sticky substances to improve production yield. Especially, sticky substances that were accumulated at the canvas of bottom part of the second dryer caused a lot of troubles. A blade type canvas cleaning device has been operated in conjunction with a high-pressure water type cleaning device since June 2012, and they have been very effective for reducing defects. We report the consideration of introduction and our operating experience.

Quality Control of Converting Paper for Food Container

Tadashi Matsuzaki and Yuichi Kaminuma
Oji F-Tex Co.,Ltd..

  Oji Paper Group moving into a holdings structure in October 2012, Oji Specialty Paper Co., Ltd. changed its name to Oji F-Tex Co., Ltd. . We are determined to enlarge our gDiverse Products Lineuph, the distinctive specialty printing papers, specialty paperboards, functional papers, films and converted products.
  Our high-grade paperboard and specialty paper are used in variety food containers and packaging. Such as paper for liquid packaging, cups for instant-noodle soup, ice creams, yogurts and greaseproof paper for hamburger wraps along with glassine based cooking papers and so on. BOPP (Biaxially Oriented Polypropylene) films are also available. We manufacture from specially selected pulp into consideration when designing products, so as to maintain food quality and safety. Our products are also very easy to fold so customers can design packages that assert their uniqueness.
  We work to use environment-friendly materials, and ensure production safety based on Oji Group's gProduct Safety Charterh as well, when we purchase materials. We also adopt the standard set by Japan Paper Association and Japan Food Sanitation Act.

Improvement of Frost Resistance of Concrete by Pulp Addition

Yuki KamiyaCHiroyuki Tanaka and Soichi Takahashi
Chuetsu Pulp & Paper Co., Ltd.
Shinichi Yamada
Hokuriku Electric Power Company
Keita Shimonakamura
GEOSTR Corporation
Yoshitaka Koshimura

  Recently, the amount of generated coal ash has been also increased. Therefore, effective utilization technology of coal ash should be developed urgently. The coal fly ash is a fine particle fraction of coal ash, has been already utilized for the improvement of durability and fluidity of the cement concrete. However, it is known that there is a problem in durability and strength of concrete containing with high percentage of fly ash. Therefore, fly ash content of the cement concrete is usually 15% or around, and to be 30% at most.
  In this paper, we attempted to the prevention of decreasing of strength and durability in high fly ash-containing concrete (substitution ratio: 60%), by pulp addition. The mechanical strength change due to material age was measured, and freeze - thawing test was also carried out as an indicator of durability. As a result, by pulp addition to the concrete with high substitution of fly ash, the mechanical strength was reached to sufficient value for withstanding practical use, and also the frost resistance was dramatically increased. Although the mechanism is unknown, it was presumed that addition of pulp fiber has inhibited of separation of fly ash and cement particles due to the density difference. In addition, it was expected that the reduction of damage from freeze-thawing cycle by the hollowed structure of pulp fiber has resulted expression of high frost resistance.

Lime Kiln Capacity Upgrade and Optimizing Its Operation

Koji Nigorikawa
Iwakuni Mill, Nippon Paper Industries Co., Ltd.

  Iwakuni Mill and Otake Mill in Nippon Paper Industries are located adjacent to each other. They needed to reorganize the production structure of pulp and paper for the purpose of recovering profitability.
  As one of the measure of this, we tried to make Kraft Pulp more competitive by shutting down the production of pulp at Otake Mill permanently, consolidating their production into Iwakuni Mill.
  For this reason, it has become more important to produce pulp stably. To achieve this, there was priority issue-einsufficient capacity of recausticizing process' to be solved. Especially capacity of hot lime production in kiln was bottleneck in our recausticizing process when we make up enough white liquor for two digesters in full swing. To increase hot lime production, we have modified the process and optimized operating condition and utilized add-on chemical. And then we have finally achieved to produce sufficient white liquor and debottleneck Kraft Pulp production.

Design of New Retention Aid Polymer

Goichi Hayashida, Naho Murata, Yoshimi Yoshioka and Yukiko Minegishi
Shonan Reserch Center, HYMO Corporation

  Recently, paper-making environment has become more severe because of increasing fine fiber, ash and anionic trash. Therefore, the effects of conventional retention aids are not enough. Focusing on controlling the intertwinement of the polymer chain, we designed new retention aid polymer showing high performance even if the amount of fine fiber is high.
  In general, increasing molecular weight of polymer causes intertwinement of polymer chain. It decreases charge interaction between polymers and fibers. However, the charge interaction is important for fine fiber particularly. For the purpose of developing new retention aids having both high agglomeration ability and high reactivity of charge interaction, we controlled the conformation to reduce the intertwinement of the polymer chain keeping high molecular weight.
  We examined the new developed-polymer by measuring molecular weight, radius, viscosity and speed of charge interaction. These results supported that the new developed-polymer had less intertwinement and its charge interaction was faster than that of normal linear polymer. As expected, new developed-polymers showed higher retention rate than normal linear polymers in the case of high amount of fine fiber.

Water Based Barrier Agent for Food Packaging Paper,gEXCEVALh

Yosuke Kumaki, Masako Kawagoe and Shigeki Takada
Kurashiki Plant, Kuraray Co., Ltd.

  EXCEVAL is a hydrophobically modified special polyvinyl alcohol (PVOH) which provides higher water resistance and higher gas barrier at high humidity condition. In this paper the properties of coated paper with EXCEVALTM by size press is characterized. The coated paper provides lower air permeability and it results in better barrier against oil & grease compared with fully hydrolyzed PVOH. This performance is enhanced by combination with platy minerals. EXCEVALTM has been registered as a Food Contact Substance in FDA and it has various potentials to be used in food packaging papers.

Optimization for Reject System of Stock Preparation by Combisorter

Masamori Tanaka
Voith IHI Paper Technology Co., Ltd.

  The reject system handling is getting more and more difficult recently because not only of worse quality of raw material but also of the change of flow concept. For the latest screening system, coarse and fine screening can be combined. This change has been available by technological development of pulping and screening. At the same time, coarse and fine rejects are mixed together and the reject contains contaminants with much kind of size and character. Usually several machines and not so small energy are necessary to treat this reject, but CombisorterT which is combined with screening, deflaking, and dewatering function within one machine should be the best solution for simple flow system. This article shows the introduction of Combisorter and its advantage for the optimization of reject system.

Biology and Management of Nuisance Midges (Diptera: Chironomidae) in Paper Mills

Goro Kimura
Technical Research LaboratoryCIKARI Corporation
Masahiko Konishi
Sales Development DepartmentCIKARI Corporation

  Adult chironomids emerging from eutrophic lakes or polluted bodies of waters have become intolerable because their high densities are a severe nuisance and cause economic problems. Generally, these adults invade from the outdoor habitats, however, Limnophyes natalensis also emerged from the indoor drain pit. We investigated following three subjects: (1) seasonal abundance, (2) flight behavior, and (3) management of L. natalensis.

Profit Creation and the Process Stability Operation System Construction

Kazuo Yanagi
Japan Business Innovation Consulting

  We contract with the famous process industry about consulting of "profit creation and the process stability operation system construction" recently. Much consulting themes are improvement of the manufacturing yield, and reduction of machine troubles.
  Content of consulting is to improve "chronic defectiveness" having difficulty in carrying out measures.
  The following points are necessary to carry out "chronic defectiveness" measures effectively.
1. Understanding in detail of "a phenomenon" and "a production principle" and "the facilities structure".
2. Adopting the way of thinking of a functional thing and understanding the actual situation that a poor phenomenon is taking place.
3. All the examination members can catch an object for an image by illustrating an object.
4. Organizing a team to constitute from the member of the ace to examine "a peculiar technique"C and building the structure which raise the synergy with "the management technique giving by consultants
  This lecture shows the main point about "the solution to improve chronic defectiveness"

Report on the Results of the Fiscal 2013 Follow-up Survey on JPA's Committed Action Plan and Efforts against Global Warming in the Japanese Pulp and Paper Industry

Kazuo Ikeda
Japan Paper Association

  The Japan Paper Association (JPA) has been actively working to save energy since 1997 when it established its gCommitted Action Plan on Environmenth. JPA declares its policy of restraining CO2 emissions in the action plan, and has worked toward the following targets:
  ·On a five-year average basis from fiscal 2008 to fiscal 2012, reduce specific fossil energy consumption and fossil energy derived CO2 emission intensity by 20% and 16% from the level of fiscal 1990, respectively
  ·By fiscal 2012, expand forest plantation area owned or managed by the industry at home and abroad to 700 thousand hectares.
  According to the fiscal 2013 survey, fossil specific energy consumption per ton of paper production and fossil energy derived CO2 emission intensity in fiscal 2012 reduced by 24.8% and 20.3%, respectively, compared with the level of fiscal 1990. This is mainly thanks to manufacturersf continuous efforts such as energy saving and energy conversion from heavy oil to biomass and waste energy. On the other hand, forest plantation area at the end of the fiscal 2013 was 676 thousand hectares, falling short of the 700 thousand hectares target.
  In addition to the results of the follow-up survey, this report introduces the energy situation in the Japanese pulp and paper industry, and information such as JPAfs Action Plan for low-carbon society and the impact of the raise in electricity prices on the industry after the Great East Japan Earthquake.

The History of Paper Machine Development: 100 Years from Robert's Invention
Part 1: The Invention of Paper Machines, Fourdrinier and Cylinder Mould

Kiyoaki Iida

  Louis Robert, Frenchman, invented paper machine in 1798. His machine was 10 feet long, had only a wire part and made paper of 24 inch-width by hand wheel drive, With funding by Fourdrinier brothers and mechanical capability in England, a proto-type model of a machine which would be called Fourdrinier machine and be used for almost 200 years was perfected in just 10 years.
  Cylinder mould machine which have been mostly used for paperboard production until now was also invented in England at the same period of time, The technology was imported into the U.S. and domestic machine suppliers improved the machine and their efforts helped them to become worldwide players in the 20th century.
  Many factors contributed to the quick development of paper machine, some of which were well-trained mechanical engineering using iron and steel instead of wood, robust paper demand, and active information exchange supported by international patent system. One decisive factor is the presence of entrepreneurs energetically engaged in technological development like Fourdriniers, Donkin, Dickinson in England and Gilpin and Ames in America.
  The Fourdrinier machine was further modified, adding up improvements in dryer, calender and cutter. In around 1900, it was 150 inches wide and ran at the speed of 600 feet/minute.
  The development will be discussed in the part 2.

  |Peer Reviewed|
  Introduction of High Performance Activated Sludge

  Masayuki Watanabe a) , Keiko Fujita, Miyuki Nakagawa and Hitoshi Okada
  Japan Pulp and Paper Research Institute, lnc.
  a)Current Affiliation : NPi Research Laboratory, Nippon Paper Industries Co., Ltd.

  We have studied activated sludge (AS) in order to improve the efficiency of wastewater treatment. We previously reported that the performance of each millfs AS was different, and that the high performance AS enabled us to improve degradability of other millfs wastewater on a bitch experiment.
  At the next step, we used a continuous experimental apparatus, which have the condition similar to a millfs plant. Using this apparatus, we conducted the experiment assumed that the high performance AS is introduced into the mill having the problem of wastewater treatment. As a result, we found out that blend of 20% of the high performance AS with the conventional AS made degradability of wastewater improved. Genetic analysis revealed that original bacteria of the high performance AS existed in the blend AS during treatment of wastewater. In addition, substrate utilization assay showed that carbon source utilization profile of the blend AS was more similar to that of the high performance AS than the conventional AS, suggesting that bacterial community in the blend AS became similar to that of the high performance AS after blend.