All issues
Volume 25, Issue 5
Displaying 1-10 of 10 articles from this issue
- |<
- <
- 1
- >
- >|
-
[in Japanese]1971 Volume 25 Issue 5 Pages 61-63
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSDownload PDF (579K) -
Tomomata Katayama1971 Volume 25 Issue 5 Pages 223-225
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSDownload PDF (1267K) -
Kunihiko Okamoto1971 Volume 25 Issue 5 Pages 226-234
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSDownload PDF (1904K) -
[in Japanese], [in Japanese]1971 Volume 25 Issue 5 Pages 235-241
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSDownload PDF (1465K) -
Electron Spin Resonance and After Effect of Irradiated PulpsTakeo Ueno, Tatsuo Yamauchi, Rikizo Imamura1971 Volume 25 Issue 5 Pages 242-249
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSThe free radicals formed in the irradiated pulps and the after effect of irradiation (that is, post-irradiation depolymerization) have been investigated.
The degree of polymerization (DP) of gamma-irradiated pulps progressively reduces up to a few weeks in air at 20°C, but with heat treatment this period is shortened, for example, with only 15 hours of heat treatment at 60°C, DP of pulps settles down to a definite level.
Also radicals formed by irradiation, detected and determined by electron spin resonance (ESR), decay very slowly at 20°C, but heat treatment increases this decaying speed. Although the decrement of radicals and the reduction of DP change in the similar tendency at relatively low temperature, the latter exceeds the former at above 100°C. Therefore, it may be said that, at high temperature, main chain scissions which are independent of the decay of radiation-induced radicals take place in pulps. However, this phenomenon occurs as well in original pulps.
Heat treatment has negligible effect on the analytical properties of low DF pulps except that the higher temperature, the more copper number. On the other hand, “true” carbonyl groups estimated by cheletometric titrationmethod after oxidizing to carboxyl arc unchanged. This fact shows that alkali seensitivity of pulps which has been given by irradzation becomes much greater by heat treatrnent.
In relation to the measurement of ESR absorption for the determination of radicals in pulps, it is observed that microwave power give a large effect on the pattern of absorption spectra. Namely, although at relatively low microwave power, ESR spectrum of irradiated cellulose shows five peaks, as the power gets higher, especially in cellulose I, the spectrum becomes “difuse”, and finally it shows only three peaks. This is important fact as to the discussion on the positions of radicals in irradiated cellulose, and moreover, considering as well that the patterns of the spectra decayed by heat treatment vary in accordance with temperature, it is appropriate to speculate that several species fadicals exist in irradiated cellulose molecule.View full abstractDownload PDF (2345K) -
On the Mechanics of Air Knife CoatingMitsuru Kondo, Satoshi Dotani, Yasuyoshi Nishibayashi1971 Volume 25 Issue 5 Pages 250-255
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSThe importance of the flow properties of coating colors, especially in view of the modern high-speed air knife coating technique of application, is discussed.
While PVA/clay coatings appear to have normal rheological properties when measured by usual viscometers, they cannot be applied on air knife coater to give smooth, pattern-free coatings.
Certain factors affecting the flow properties of the coating colors, when application was carried out by the air knife coating method on test coater, were investigated with the aid of a high pressure capillary viscometer.
It was found that a relatinship between the flow properties of the coating colors and the pattern-formation existed, and the pattern-formation decreased with the increase of the lengths of a streamline flow to be measured by the viscometer.
While no general rule applicable to the practical high-speed air knife coater could be derived from this work, the principles and techniques involved could be applied to the coating colors to be used in a definite application process.View full abstractDownload PDF (1621K) -
Koichi Kawai, Yoshiro Ii, Seiya Akino1971 Volume 25 Issue 5 Pages 256-262
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSFive New Zealand pine and three beech (Nothofagus) species were examined for kraft pulping, Each species of the pines and beeches was easily pulped and gave pulps in good yields and brightness. However, the red and hard beeches which contained large amount of extractives gave lower yields and brightness compared to the pulps from the same species of smaller diameter which contained lower extractive contents.
The pine kraft pulps had similar bursting strength and tensile strength to those of Japanese pine, but had slightly lower tear strength.
All strength properties of the pulps from the New Zealand beech species were in the lower grade than the Japanese mixed hard wood pulp.View full abstractDownload PDF (2290K) -
Shogo Tsunoda, Minoru Furuta1971 Volume 25 Issue 5 Pages 263-268
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSDownload PDF (1156K) -
Tadashi Takakura1971 Volume 25 Issue 5 Pages 269-278
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESS -
Taku Suzuki1971 Volume 25 Issue 5 Pages 279-282
Published: May 01, 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESS
- |<
- <
- 1
- >
- >|