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Volume 33, Issue 8
Displaying 1-7 of 7 articles from this issue
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Akira Yamaguchi1979 Volume 33 Issue 8 Pages 491-499
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
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A. M. Ayroud1979 Volume 33 Issue 8 Pages 500-508
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
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Kure Mill, Toyo Pulp Co., Ltd.[in Japanese]1979 Volume 33 Issue 8 Pages 509-522
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
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Kuninori Usami, Atsumi Nishida, Hiroshi Kumagai1979 Volume 33 Issue 8 Pages 523-528
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
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Tsuneaki Kijima, Isao Yamakawa, Hidehiko Nii1979 Volume 33 Issue 8 Pages 529-535
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSThis paper is intended to measure the moisture content under the various humidity and temperature and shrinking stress during desorption for handmade sheets and laboratory foundrineir machine made sheets.
The relation between the stress and moist-expansivity was also discussed for above mentioned sheets. The results obtained are summerized as follows :
1) Under the same relative humidity, papers showed slightly higher moisture contents at lower temperature in the range of 10°C to 40°C. However, moist-expansivity of the papers were not affected by temperature.
2) There was good correlation between relative humidity and stress of papers during desorption.
3) Stress of papers during desorption varied depending on the wood species, pulping process and the degree of beating. But the relations between shrinking stresses during drying and desorption were not different in these pulps.
4) Moist-expansivity of papers depended on the drying process, however, stress during desorption was not affected by drying process.View full abstractDownload PDF (969K) -
Gamma-rays Irradiation on the PulpKenji Mori, Kunihiko Hasegawa, Toru Sasaki1979 Volume 33 Issue 8 Pages 536-541
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSThe dissolving pulp (DP) involving no lignin and the cold soda pulp involving much amounts of lignin were used in order to study the influence of gamma irradiation.
The experimentals were carried out in the presence of air (dryed state), in the water, methanol, acetic anhydride, acetic anhydride+methanol, dioxane, dimethyl sulfoxide and 1% NaOH solution as deaerated as possible from each solutions. The irradiation was for 100 hours at the temperature of 2021°C. Total irradiation dose was 1.47 × 107 R.
The yields, lignin content, 1 % NaOH solubility, and then brightness were determined. In the case of acetic anhydride and the mixing solution of acetic anhydride and methanol the degree of acetylation also was determined.
The following results were obtained from the above-mentioned experiments.
1) Yield and analytical value
In the case of dimethyl sulfoxide which is a good solubilizer for pulp as well as especially in the case of 1% NaOH solution, the yield decreased by the irradiation.
It was found that this phenomenon was denoted remarkably for the cold soda pulp.
2) For the pulp immersed in the water the brightness of pulp was not pratically improved by the irradiation, but relatively remarkably improved for immersing in methanol. Thus phenomenon was observed in both DP and the cold soda pulp. The improvement of the degree of brightness is not the change in quality of lignin, but it may be considered reasonably to take place by the action of oxidizing bleach with a smaller amount of oxygen of air remaining in the material. And also by comparison with immersing in water, it is considered for immersing in methanol that the action of bleaching arises from the presence of an extremely small amount of oxygen. Additionally, 1% NaOH solubility gets a small value in the both systems. Therefore, it may be considered that the degree of brightness is improved by the oxidation reaction, but the degradation degree of pulp gives a small value.
3) From the scope of results obtained by the infrared analysis. it seems most reasonable to conclude that methanol does not react with lignin in the cold soda pulp even on irradiating.
4) In practice, it was found that the acetylation was accelerated by the gamma-rays irradiation.View full abstractDownload PDF (809K) -
1979 Volume 33 Issue 8 Pages Preface1
Published: August 01, 1979
Released on J-STAGE: November 10, 2009
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