Multistage Bleaching Research Articles

Studies on Hardwood Resin (1)

To obtain some fundamental knowledges of pitch deposition on multistage bleaching process of hardwood braft pulp, chemical composition of pitch was investigated.From the neutral fraction, squalene, β-sitosterol, and an unknown steroidal substance was isolated and identified.The existence of myristic-, palmitic-acids, a new fatty acid C30H6003m.p 7272.5°, and linoleic acid was shown by paper chromatography and preparation of those characteristic derivath cs. The conversion of pitch from fresh resin to trouble deposits was discussed in terms of its composition.

ON THE BARKS OF RIKUTIMEN, GOSSYPIUM HIRUSUTUM, L.

On the barking test of the cotton stalks, authors had suggested that the ultization values of the Gossypium hirsutum, L. 's barks for the source of cellulosic fabrics are superior than Gossypiumarboeum, L. in part I. And in part II, authors reported that the biochemical characteristics of the bast fibers were manifested by the Honda's rational proximate analysis of the Gossypium HirusutumL..In this report, we digested the barked cotton stalks with kraft cooking liquor. With these cooking experiments, however, could not investigate optimum cooking condition, we gained the pulps, which are similar to semichemical pulps. Although the cookings were insufficient, those unbleached pulps are bleached well by multistage bleaching.By the purpose of the utilization of pulps, such as rayon pulps or paper pulps, we should select the process of multiple bleaching. Then, if we control the bleaching condition in multistage bleaching, would gain characteristic bleached pulp from the unbleached kraft pulp. And these data of the cookings and the bleaching are showed in figures and tables.

Bleaching of Wood-pulp

IN connexion with the article on "Wood Pulp and the Futur" (see NATURE, 139, 867, May 22, 1937) we have received a letter from the Development and Research Department of the Pennsylvania Salt Manufacturing Co., 1000 Widener Building, Philadelphia, pointing out that the use of an emulsion of chlorine in water in multi-stage bleaching processes is the result of investigations made by this Company and is patented in twelve countries. It may be stated that the writer of the article was fully aware of the part played by the organization concerned in developing this particular method of bleaching. In a short survey covering such a wide field, however, it was not considered necessary to give references to the work of individual firms ; in the case of bleaching processes in fact, this would indeed have been a particularly difficult matter, owing to the large number involved.