|2012 January JAPAN TAPPI JOURNAL
Vol.66, No.1 Abstracts
-The Latest Refiner Plates-
Sales & Technical Department, AIKAWA IRON WORKS CO., LTD.
By worsening of electric power supply situation in recent years, Japanese industries are being required to increase efforts for energy saving. Though our paper industry had already reached high level of energy saving, still it is not exception. Historically, refining stage in stock preparation which needs especially big energy had been modified to reduce power consumption constantly. Now the time it should become the key point for energy saving, again. Also, from old term, it is well known that refining stage is the most important for defining character of paper. The refining technology had been evolved in accordance with the transition of stock resources and paper making technologies. And now the turning point has turned up to the refining stage, because not only waste paper fibers, but also main virgin fibers, had become shorter. In this paper, AIKAWA introduce “Finebar” - the latest refining plates which is the best for these days thus it brings upgrade for product by smaller power consumption. Please find out Finebar's feature, its revolutionary performance and its future possibilities.
-Learn from the Earthquake Disaster-
Mitsubishi Paper Mills Limited
Hachinohe Institute of Technology
The great east Japan earthquake disaster occurred on March 11 2011, and the Hachinohe Mill of Mitsubishi Paper Mills was hit by the earthquake of a seismic intensity “5-upper” and a tsunami of 8.4m in height.
There was minor damage caused by the earthquake to the mill, but the damage caused by the tsunami was quite severe. The mill is still on its way of reconstruction and revival. The damage of the mill by the earthquake and tsunami and geographical data of tsunami are presented together with the mills reconstruction and revival plan and its progress.
-Meeting the Challenges Today for a Stronger Mill Tomorrow-
Nippon Paper Industries Co., Ltd.
Our three mills in the Tohoku region were severely damaged by the 9.0-magnitude earthquake, which was the largest-ever recorded in Japan, occurred at 14:46 on March 11, 2011 and the massive tsunami afterward. We have established Disaster Recovery Division in the headquarters in order to achieve a prompt recovery from the severe damages.
In this report, we will report on the recovery progress we have achieved up until the present together with the actions toward rebuilding disaster-resistant mills including the framework.
Operating Experience of ECF Bleaching
-Application of Peroxymonosulfuric Acid Bleaching into Mill Scale-
Tomioka Mill, Oji Paper Co., Ltd.
The Elementary Chlorine-Free (ECF) bleaching process for kraft pulp (KP) has prevailed. We faced the problem of discoloration of ECF bleached pulp. We have known that hexenuronic acid (HexA) in ECF bleached pulp plays an important role in brightness reversion (yellowing) of the pulp, and studied ways to remove HexA. We overcame many difficulties, and established industrial methods and equipment to produce peroxymonosulfuric acid in continuous ways. This method and equipment was first adopted in the world at Tomioka Mill.
In this paper, we introduce the introduction of MPS method and operating conditions.
Operating Experience of Blade Type Canvas Cleaning Facility
Fuji Mill, Oji Paperboard Co., Ltd.
Oji paperboard Fuji PM10 produces corrugating medium 560 tons per day. The mill uses OCC for the furnish mainly, and Key issue is to remove foreign substance. Especially it’s difficult to remove pitch and sticky substance completely in pulping process and then it gives various problems in whole paper making process. At dryer section the various measures has been executed to eliminate them because the dryer fabrics catch them up very easily. The super high pressure cleaner has been installed for single run dryer fabric at 1st dryer section and operating with good results. However this kind of cleaner is essential to keep clean with regular maintenance. Therefore first of all, easy maintenance cleaner was demanded when we plan to install second one. As a result, blade cleaning system (AOKI cleaner) was installed at 2.nd bottom dryer section in July 2010. We introduce the latest blade cleaning system and its effect operating.
An Operating Experience
-Retrofitting Carried Out to Reinforce Nip Pressure at PM7 No.2 Press Section-
Yashio Mill, Rengo Co., Ltd.
As companies are expected to take environmental actions, Rengo established “Eco Challenge 020” as the company’s environmental action plan and is strenuously working to reduce the carbon emissions by 32% in 2020 compared to 1990 levels.
Given the above background, retrofit was carried out at Yashio Mill PM7 (medium machine) with an aim of improving the productivity as well as reducing the steam consumption; nip load was increased from 1000kN/m to 1200kN/m in order to improve dewatering capability. The outline of the retrofit and an operating experience will be discussed in detail below.
Environment-friendly Corrugated Board Adhesive without Boron Compound
Oji Cornstarch Co., Ltd.
Boron compound (borax), one of the ingredients of adhesive used for corrugated cardboard has been major in manufacturing adhesive. However, it is reported that boron compound is likely to be harmful to the human body and its concerning substance is on the list of law REACH in Europe. We have found Sepiolite, alternative substance from natural mineral that can be used to adhesive for corrugated cardboard on some points of water retention and well-expressing viscosity (we believe that). This adhesive without boron compound retains physical properties of conventional laminatability and operation, also very environment-friendly.
Bottom Ash Recycle at Circulation Fluidzed Bed (CFB) Boiler
Akita Mill, Nippon Daishowa Paperboard Co., Ltd.
Nippon Daishowa Paperboard Co., Ltd. (NDB) has installed coal and wood chip co-firing circulating fluidized bed boiler at Akita Mill in 2008. After new power plant installation, oil boiler was stopped and used as a backup power.
NDB has reduced the energy cost by fuel switching from oil to coal, and also reduced the CO2 emission by utilizing wood chip as a fuel. However currently the cost of disposal ash generated from fuel combustion, and the cost of additional bed material are a cause of an increase in the total running cost.
In this paper, we introduce about the outline of the bottom ash recycle system installed in Aug 2010 to further reduce the running costs and actual operation experiences.
Development of Mass-propagation Method of New Tea Cultivar “Sun Rouge” Containing High Anthocyanin Content
Research and Development Department, Agri-Biotechnology Research Laboratory, Nippon Paper Industries Co., Ltd.
Through research and development of afforestation technology, Nippon Paper Group has cultivated a photoautotrophic culture technology for increasing cutting plantlets and seedling growth technology for healthy plantlets. To date, the Group has produced and marketed seedlings of horticultural crops (e.g., cherry trees and eucalyptus for flower arrangement) and vegetables (e.g., sweet potato), green teas. Reacently, Nippon Paper Group, in cooperation with the National Institute of Vegetable and Tea Science at the National Agriculture and Food Research Organization (NARO), has developed “Sun Rouge”, a new species of tea with high anthocyanin content. In this report, mass-propagation method of “Sun Rouge” is investigated.
Insect Control Activities Conducted at Katsuta PM1
Kanto Mill (Katsuta), Hokuetsu Kishu Paper Co., Ltd.
Insect contamination of products is one of the most serious problems for paper manufacturers that causes complaint from customers and may lose confidence as company. We have performed various insect control activities at Katsuta PM1.
Generally, reducing negative air pressure inside the paper machine building is effective for insect control. Since November, 2010, we have done several works that include the change of air source of dryer air supply fans and the installation of building air supply fans.
As a result, these contributed to the reduction of negative air pressure that achieved the decrease of insects.