Small amount of surfactants ranging from 0.1 to 0.2 per cent such as anionic, cationic and nonionic were applied to sulphate dissolving pulp from red pine (Pinus densiflora) and the effects to improve processability for viscose preparation were observed.
Certain kind of surfactants were found to be considerably effective on shredding of alkali cellulose obtained from sulphate dissolving pulp, i. e., the amount of adhered alkali cellulose onto the blade and the inner wall of shredder can be diminished and the shredded crumbs become fluffier and more voluminous in shorter shredding time.
Stickiness of xanthate can also be diminished by addition of small amount of certain surfactants in the pulp sheets.
In some cases, the surfactants were regarded to be effective for improvement of the filterability of viscose prepared from sulphate dissolving pulp, although the viscose filterability would chiefly depend on the quality of the pulp itself.
In general case, the floating tendency of the pulp sheets during the steeping process was incited by application of the surfactants to the pulp sheets.

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Rayon grade sulfite pulp (RP, α-cellulose 92%), acetate grade sulfite pulp (ACP, α-cellulose 96%) and purified linters (Linters, α-cellulose 99%) were oxidized by ClO₂ solution under the following condition : ClO₂ (as avail. cl.) add. : 0-40% basis B. D. pulp, temp : 70°C, initial PH : 3-11 (unbuffered), and average D P, copper number, carboxyl content, brightness, methoxyl content and also U. V. absorption spectrum of these treated pulps in ca. 80% H₃ PO₄ have been determined. The results areas follows :
1. With RP, the rate of oxidative degradation of cellulose by ClO₂ solution is very mild, with consequence of selective dissolution of residual lignin without affecting any influence upon functional groups (e. g. carboxyl, carbonyl groups). However, under the presence of extremely high amount of ClO₂ in the range of PH (initial) 7 or more, the degradation of cellulose also progressed gradually,
2. On the other hand, linters and ACP are very susceptible to the oxidation by C1O₂ and are apt to suffer from appreciable degradation, with consequence of decrease in a-cellulose, Cu-NH₃ viscosity, and increase in copper number and carboxyl content.
3. From these results it has been found that the noncellulosic material such as lignin and especially hemicellulose associated with cellulose has the protective action against the heterogeneous degradation of cellulose by ClO₂ solution. This phenomenon could be explained by preferential consumption of oxidizing agent by noncellulosic material. With this point, further discussion will be published in next report.
4. It has been found that the oxidized cellulose and hemicellulose have characteristic U.V. absorption spectrum near 290mμ.

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The principle of this unit had been described on previous report. Based on this principle the experimental installation has been constructed and investigated to determine the dewatering effect by compressed air, at the Laboratory of Kyoto University. For this purpose an apparatus was constructed with a wire cylinder and the blow box which combined with a derivery of Nash pump .The method and result of this experiment are described.

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