PURIFICATION OF WOOD PULP: JAPANESE PULP AS RAYON MATERIALS

Hazime Okada; Takichi Matsuda; Eiji Hayakawa

doi:10.2115/fiber1925.5.225

Hazime Okada, Takichi Matsuda, Eiji Hayakawa

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JOURNAL FREE ACCESS

1929 Volume 5 Issue 9 Pages 225-233

DOI https://doi.org/10.2115/fiber1925.5.225

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Published: 1929 Received: - Available on J-STAGE: November 27, 2008 Accepted: July 13, 1929 Advance online publication: - Revised: -
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Date of correction: November 27, 2008 Reason for correction: - Correction: DTRECEIVED Details: Wrong : 19290713

Date of correction: November 27, 2008 Reason for correction: - Correction: ABSTRACT Details: Wrong : It is a well known fact that the quality of a sulfite wood pulp is greatly improved by an alkaline re-digestion. And so far as it relates to the alkaline digestion itself, there remains no question to be tiolved, But as to the question, whether we should firstly bleach and then digest the bleached pulp, or firstly we should digest the unbleached pulp and then bleach, there are two opposite views. As they have both their own merits and demerits in view of the economy of the operations and the quality of the purified pulp to be requested, we cannot make a general statement as to the superiority of either one. But there are a marked distinction in the following features between these two processes. In the former process, although we can not do without a weak bleaching after digestion for finishing, it is easily obtained a perfectly whit- pulp of low copper number. But the α-cellulose content and the viscosity are not satisfactory. In the latter process, the α-cellulose content of the finished product is excellent, but the copper number and the whiteness are inferior than in the former. The viscosity also is liable to become low. The manipulation of the bleaching is also very difficult. The authors, having attempted to find a process, which has the merits and have not the demerits of the both processes, came to an improvement. Thus, the following schedule is the best, not only in the easiness of the manipulation of the bleaching and economy of materials, but also in the all physical and chemical properties of the purified pulp. Firstly the raw unbleached pulp is bleached so as to consume the 40% chlorine of the chlorine consumption value of the pulp of the ordinary condition of bleaching. Secondly thus imperfectly bleached pulp is digested by an ordinary method. Thirdly thus digested pulp is slightly bleached for firnshing; in this last operation only a small amount of bleaching powder is sufficient to bleach the pulp to a perfect whiteness, the manipulation of the bleaching is consequently very simplified and the cellulose is not liable to be degraded.
The authors have also investigated on the digestion after .the chlorination of the pulp by chlorine water and have noticed that it gives the best results in all respects.
Now that the qualification of our home pulps for rayo.i materials is the problem under discussion, at present, iu our country, rayon pulps now being wholly imported from abroad, the authors have prepared the viscose silks from several cellulosic materials, including an cotton tissue paper, an imported rayon pulp, and a japanese pulp purified by our method, and have attempted to give some references to the problem.
It was found that the several properties of the silk, from the purified japanese pulp, especially the wet tenacity, were superior to those from the ordinary rayon pulp.

Date of correction: November 27, 2008 Reason for correction: - Correction: PDF FILE Details: -

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