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Volume 48, Issue 11
Displaying 1-12 of 12 articles from this issue
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J. Hayashi1994 Volume 48 Issue 11 Pages 1397-1409
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSIn 1961, we developed the alkali-oxygen bleaching method and commercialized it to minimize envilomental pollution. The characteristics of the method were in high pulp consistency to perform delignification under minimum degradation of cellulose. In the method oxygen was supplied to a pulp through a thin alkali solution layer on the pulp. And reactions were controlled by the supplying rate of oxygen. The condition protected cellulose which was less oxidizable than lignin. The idea was supported by the results that additions of glucose and water soluble lignin brought protect effect to cellulose in the high pulp consistency as the result of their preferential consumption of the oxygen. In the low pulp consistency (1.2%) the addition of them accelerated the degradation of cellulose. The substances showed the two opposite effects. protection and degradation. Their balance was depended on their situation. When they were on the pulp surface they most protected cellulose. The characteristics allowed continuous operation of kraft cooking and oxygen bleaching using a simmple and imperfect washing, once replacement washing with hot water. The delignification reaction by oxygen was influenced remarkably by structure of lignin in the pulp. And the structures were depened on cooking condition, especially on cooking temperature. The lignin in the kraft pulp cooked at 180°C was easily removed regardless of the residual amount in the pulp. That at 160'C was hardly removed for even the pulp of lower K No.The delignification reaction was the first order reaction of the amount of lignin under excess oxygen.View full abstractDownload PDF (2410K) -
Yoshiaki Ishino, Yuji Kimura1994 Volume 48 Issue 11 Pages 1410-1428
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe methods to produce the high performance papers are roughly divided into the next three procedures, (1) the utilization of functional fibers as paper raw materials, (2) the control of fiber aggregation structure to give higher performance, and (3) the composition with another functional materials. In this paper, some examples of the high performance papers produced by these procedures are introduced.
As the products by the procedure (1), a transparent electroconductive sheet manufactured by using electroconductive fibers and synthetic pulp, a water-soluble paper consisted of fibrous carboxymethylcellulose and wood pulp, and a water-absorption paper which is a poly-ion-complex sheet of fibrous carboxymethylcellulose with a cationic polymer are taken up and explained.
The typical products by the procedure (2) are air and liquid filter papers. Here wood or non-wood pulp and synthetic fibers different in their fiber diameters which are available for the papers, are discussed. In addition, an air-permeable oilproof paper using to bags for fried foods is explained.
As the examples of the procedure (3), the products obtained by utilizing coating technologies are explained, such as a UV light-, oxygen-, or temperature-detectable sheet and a liquid-sensitive sheet.View full abstractDownload PDF (3735K) -
Takahiro Shimazoe1994 Volume 48 Issue 11 Pages 1429-1439
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSRecently large changes in newsprint are observed. That is, the changes are promotion of lightweight, accelerated increase of web offset printing, increase of multi-colored printing and increase of the rate of using of recycled paper.
The feature of web offset printing in newsprint is to use cold set type ink. Accordingly the drying after printing is done by absorption in newsprint without oven.
One of important property of the newsprint is fast ink setting. Also higher picking resistance is required for good print quality at high speed printing of newsprint.
For this purpose coated newsprints by starch and polyvinylalchol are generally used today.
High brightness newsprint and pigment coated newsprint are mainly used in sports newspaper. They have clear print qualities.
The rate of ultra lightweight newsprint is about 81.8% today. The rate of web offset printing in newsprint is over 86% today.
In recent Japanese public patents many applications of improvement for newsprint is observed. There are the improvement by the change of pulp composition, the improvement by surface sizing agents, the improvement by starch, PVA and latex, the improvement by pigment coating with latex, the improvement by calendering condition and so on.
In Japan there are many different newsprints in paper weight, brightness, opacity, absorption degrees of oil, picking resistance, ink receptivity and ink set.
Today in Japanese coated newsprints by gate roll coater with starch are increasing. This trend will continue in future.
Our test results of coated newsprint by starch, starch/latex blend and plastic pigment showed possibility of improvement (brightness, picking resistance, especially wet pick resistance, and ink receptivity).View full abstractDownload PDF (1849K) -
Carl Zotterman1994 Volume 48 Issue 11 Pages 1440-1446
Published: November 01, 1994
Released on J-STAGE: November 29, 2010
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Koji Kiuchi, Ayako Sekikawa, Kei Etoh1994 Volume 48 Issue 11 Pages 1447-1452
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSIsothiazolone compounds are widely used as industrial preservatives for the coating color of the paper making machine, adhesives, latexes, etc, and as the industrial slime control agents.
Although this Group of compounds is highly active for bacteria, it is irritative for human skin, and decomposed in a short period of time, especially in alkaline conditions. To improve these disadvantages and to control the release rate of the preservative this compound it has been made into microcapsules.
In this paper, efficiency of the preservative in the coating color, the release of the active ingredient into water from the capsules and safety data of the microcapsules are described.View full abstractDownload PDF (1397K) -
Takanori Miyanishi1994 Volume 48 Issue 11 Pages 1453-1462
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESS -
Wood Science Committee1994 Volume 48 Issue 11 Pages 1463-1473
Published: November 01, 1994
Released on J-STAGE: November 29, 2010
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1994 Volume 48 Issue 11 Pages 1474-1480
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (2975K) -
[in Japanese]1994 Volume 48 Issue 11 Pages 1486
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (241K) -
Kazuo Nakanishi, Kotoe Goto, Takashi Ito1994 Volume 48 Issue 11 Pages 1487-1491
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSIt is suspected that there is a surface layer which structure is different from the inner part of the coated layer. And it might be easily considered that the structure of real cross section is broken when microtomed. The broken layer might cover the real cross section. The observation of the structure of the coated layer by a scanning electron microscope must be considered very carefully.
Herein, we introduce a new technique to remove the above-mentioned layers in order to observe the inner or real structures.
The technique includes argon ion etching procedure of the coated layer stained with osmium tetroxide. This etching is assumed to remove the layers resulting in clear observation of the structure.
Using this technique, we can observe the coated layer structure more precisely. Application of this to two types of coated paper made in different drying temperature and to two kinds of coated paper of different air permeability shows effectiveness clearly and gives resonable results.View full abstractDownload PDF (1439K) -
Takashi Bando, Takeshi Adachi, Hiroshi Iwata1994 Volume 48 Issue 11 Pages 1492-1498
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSAs the first step of a drainage mechanism study on a blade type Twin-Wire forming, a pulse pressure generation mechanism was investigated from an experimental stand point of view in the previous report.
This report relates to a theoretical analysis of the drainage mechanism. A drainage model and a simulation program have been developed based on the hypotheses made up in the first step. The simulation results affirmed the hypotheses, i.e., the pulse pressure is generated by a change in a stock thickness between two wires when the stock is chocked at a leading edge of a blade and primary factors affecting pressure level are a breaking angle at the edge and a drainage resistance though a mat.
Through these studies the drainage mechanism in the blade type Twin-Wire forming has been established.View full abstractDownload PDF (1096K) -
1994 Volume 48 Issue 11 Pages 1499-1506
Published: November 01, 1994
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (1740K)
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