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Volume 54, Issue 2
Displaying 1-15 of 15 articles from this issue
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Mitsuru Tomizawa2000 Volume 54 Issue 2 Pages 149-155
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSRecently mainstream of chlorine dioxide plant in overseas is of R 8 process which practically dose not generate chlorine as by-product, however there arises problems in treating sesquisulphate which is a by product from R 8 plant as the usage of chlorine dioxide rises. For this circumstance. in order to decrease by product sulphate. R 10 process was developed to become operational. Furthermore, R 12 process was developed and is now in test run for practical use. Also R 13 process which produces no by product is under study.
In Japan. however, major pulp bleach sequences use chlorine, hypochlorite and chlorine dioxide, therefore R 2 H process which matches this sequence is the leading one for chlorine dioxide plants. As the circumstance is such that hypochlorite which forms large amount of chloroform in the bleach sequence might not be used in the future, transfer to R 8 process would be accelerated. Also in Japan, the required amount of chlorine dioxide is smaller than the amount in overseas, R 2 P process would be another choice.
Following conditions would be required for future pulp mills in selecting a chlorine dioxide plant :
1) Matching of bleach sequence with kind and amount of by-products, and ClO2 production capacity
2) Higher safety of the plant including environmental issues
3) Flexibility of the plant to correspond with pulp capacity increase and new technology
4) Lower cost of chlorine dioxide production totaling raw materials cost. operational cost including operation and maintenance, and facility amortizement
The shift to ECF is unavoidable for the pulp bleach in Japan from the present situation, therefore the usage of chlorine dioxide is estimated to increase by 2 to 3 times.
In view of above circumstances. R 2 P process would be a kind of provisional one, while R 8 process is expected to be one of the best options for a future chlorine dioxide plant.View full abstractDownload PDF (7244K) -
Koichiro Fujiyasu2000 Volume 54 Issue 2 Pages 156-165
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSFormamidine sulfinic acid (FAS) has been attracting attention as a new bleaching agent in the pulp and paper industry. Though FAS is less powerful for reducing groups of pulp than hydrosulfite, it works effectively for decoloring dyes in pulp suspension.
As recycled fiber is more commonly used, and ingredients such as inks and fillers originating from reclaimed papers gets diverse, FAS becomes interesting to the industry. The author shows that the two stage bleaching with hydrogen peroxide and FAS is very efficient for those troubles.View full abstractDownload PDF (2448K) -
Ryuichi Kayama2000 Volume 54 Issue 2 Pages 166-173
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSHydrogen Peroxide will be remarked more and more as a clean bleaching agent because of global environmental issues. Although Hydrogen Peroxide is a stable substance thermally, it decomposes with traces of heavy metals. Therefore some stabilizer is required when bleaching, and Sodium Silicate has been used conventionally. It has, however, a problem in which hard scales are produced, and a non silicate stabilizer is desired. PHAS (Sodium poly-α-hydroxyacrylate) has unique characteristics. Introduced herewith are stabilizing characteristics of PHAS in alkaline Hydrogen Peroxide comparing with other general chelating agents. PHAS has excellent stabilizing abilities especially in higher pH region. Hydrogen Peroxide concentration and temperature condition.View full abstractDownload PDF (2359K) -
Isamu Ohishi, Manabu Kodama2000 Volume 54 Issue 2 Pages 174-183
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSUtilization of Hydrogen Peroxide (H2O2) in kraft pulp bleaching is increasing globally due to the recent trend in the paper and pulp industry i.e., the change to ECF or TCF production system has been increasing. Nowadays usage of H2O2 is rather common technique in Nordic countries. H2O2 bleaching is friendly to environment and satisfies pulp quality and bleaching cost also.
This report explains following basic information concerning H2O2 : (1) History of Japanese H2O2 industry, (2) Production method, (3) Application, (4) physical & chemical properties, (5) Quality, (6) Applicable law, (7) Storage & handling facilities, (8) Examples of accident.View full abstractDownload PDF (2805K) -
Masanori Furukawa2000 Volume 54 Issue 2 Pages 184-197
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSChelating agents form highly stable complexes with metal ions. They are applied to various processes of many industries for preventing troubles by metals. Aminopolycarboxylic acid type chelating agents such as EDTA and DTPA have largest quantities of products compared with other types of commercial chelating agents.
This paper explains introductory chemistry of chelating agents and reports the usege in pulp industry. Additionally, new types of biodegradable chelating agents are presented.View full abstractDownload PDF (2642K) -
Takumi Sugi2000 Volume 54 Issue 2 Pages 198-205
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSMain biological problem in pulping process is fungi deposition on pulp sheet. Fungicides are generally used to prevent fungi deposition. Fungicides and the application method are described.
In addition, it is becoming more important to recover the effluent and reuse it in the deinking process. But this effluent is difficult to treat because it has high pH and contains fine suspended solids. The coagulation method, using a high charged cationic polymer can get rid of fine particles and give clear recycling water. As a result it has such advantages as high brightness, high strength of DIP and preventing pitch problem.View full abstractDownload PDF (9889K) -
Kiyoaki Iida2000 Volume 54 Issue 2 Pages 206-213
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThough the Japanese pulp and paper industry has been in unfavorable conditions compared to Scandinavian and North American countries, it has been one of big producers in the world. The technological development in the industry has played an important role for its success and it is reviewed in six categories, planning ability, raw material supply, energy saving, production technology, environment and R & D.
As seen in the paper, technologies developed in every category have supported the industry's expansion. These technical developments looks to originate from two fundamental attitudes in the industry, and they are flexibility to changes in the world and a challenging spirit for difficulties.
Information society, which makes everything available in the world, is threatening this Japanese technological lead and Asian producers are shaking the Japanese market. The industry need those fundamental attitudes. especially in the younger engineers and scientists, once again for the 21 st Century.View full abstractDownload PDF (2762K) -
Norio Fujita, Yasuhiro Mochida2000 Volume 54 Issue 2 Pages 214-221
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSRecently, many Gate roll coaters are applied for Newsprint machines and middle grade paper machines with market requirements of color printing of newspapers and magazines. The chromium plating is applied for the metering rolls because of a superior characteristic for wear resistance and anti corrosion in a long year. But the corrosion trouble occurred in the few metering rolls of newsprint machines and publication grade machines. We study about a corrosive phenomenon and a micro crack of chromium plating from a view point of electrolytic corrosion. Regarding to expansion of the micro crack, a few kind of plating is compared by a small size dynamic testing device.View full abstractDownload PDF (11327K) -
A New Approach PapermakingPaul Olof Meinander, Joji Taketomi2000 Volume 54 Issue 2 Pages 222-228
Published: February 01, 2000
Released on J-STAGE: April 23, 2010
JOURNAL FREE ACCESSSlow process response used to be a major obstacle to flexibility in paper-making, be it for quality control or grade changes. A good and coherent production program with a minimum of grade changes has therefore been a prerequisite for cost effective papermaking.
For the papermaking process to be flexible, it needs to respond promptly to any change and to stabilize fast after a change has been done. The first objective can be reached by taking grade or quality specific action as close to the forming of the web as possible. The second by reducing circulations from the process to a minimum.
The fast response is reached by simplifying stock component management and composing the stock in a minimum volume stock mixer. Fast equilibrium is reached by minimizing the volume of back-water, reject and broke circulations.
The paper presents a solution for improving the situation drastically, opening a path towards just in time papermaking.View full abstractDownload PDF (6024K) -
(Part 3) Application of EPMA Color Mapping (1)Tadahira Hamada2000 Volume 54 Issue 2 Pages 229-242
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe color mapping technique by means of EPMA (Electron Probe Microanalyzer) has been widely used effectively to measure the distribution of pulp and paper constituents such as fillers, Pigments, binder, Silicone, lignin and Xylan etc.
The color mapping technique was initially introduced by transforming monochromatic X-ray images to color distribution maps through the color filters inserted in front of SEM CRT. But this manual and delicate technique was soon replaced by more precise and automatic procedures controlled by computer. Furthermore, the striking progress of computer brought the development of wide area state EPMA which was able to measure the distribution of elements on the area up to 8×8 cm2.
In this paper, it was discribed how the EPMA color mapping techniques had been developed in the application to pulp and paper specimen.View full abstractDownload PDF (25903K) -
[in Japanese]2000 Volume 54 Issue 2 Pages 243
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (245K) -
Yoshitatsu Mori, Kiyotaka Huruta, Satoru Takeuchi, Ryuuzaburou Sueda, ...2000 Volume 54 Issue 2 Pages 244-259
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSWe developed “Kappa-number control system” of Kamyr kraft pulp continuous digester which have two kinds of linear form regression model for softwood and hardwood chips that control circulation temperature of cooking zone to stabilize Kappa number quality at Kure mill. Those models consist of II factor and residual EA [effective alkali] terms etc. and constant terms. The constant terms are modified to match with secular fluctuations by using exponential smoothing method.
Furthermore complicated operations of changing chip species frequently is executed in this digester and many control elements have to change adequately according to appropriate schedule to maintain pulp quality stable during the disturbance operation. For its purpose we developed “wood species change” and “production rate change” control system which change a series of operations automatically.View full abstractDownload PDF (8510K) -
Satoru Matsushima, Shigeo Matsushima2000 Volume 54 Issue 2 Pages 260-269
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSElastic formulations of the anisotropic deformation the wave board (WB) and singlefaced corrugated fiberboard (SFCF) under the uniform tensile load were performed. Then from those formulations. anisotropic longitudinal elastic moduli for WB and SFCF induced by elastic moduli of anisotropic element materials were determined, and the reasonableness of those formulations was ascertained by the application of experimental results under the tensile deformation.
Deformations of WB and SFCF obtained from those formulations are discussed, and the remarkable anisotropy is shown. The maximum of the deformation strength (unit tensile force per unit width) is in the machine direction, and the minimum is in the cross direction. And the WB anisotropy is obviously larger than SFCF. Normal stress σb in the machine direction for sheets of WB and semichemical medium decreases with the distance from centers of their sheet thickness and their wave height. and increases nearly propotionaly with the distance from the center of their sheets. Maximum σb is at the top of the wave height.View full abstractDownload PDF (2723K) -
2000 Volume 54 Issue 2 Pages 270-276
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (14243K) -
2000 Volume 54 Issue 2 Pages 277-278
Published: February 01, 2000
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (443K)
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