Studies on the Manufacture of Tabacco Stem Pulp III.

Abstract

In this paper, the pulping of the Tobacco stem and root with sodium sulphite liquor has been investigated.The cooking at the atmospheric pressure and the following mechanical defibration yielded the yellowed rich pulp in fiber bundle at the yield range of 66% to 73%. When the yield was lowered to 43% by the multiple stage bleaching, the brightness of pulp increased to about 73 and the mechanical properties of pulp were comparatively good in spite of remaining many sieves.In the semichemical process, the increase of cooking chemical decreased the pulp yield and affected on the brightness and strength to improve, but the changes were not appeared on these properties as the using of more chemical over than 17%. Generally, the yield of Tobacco semichemical pulp were about 55% and there mechanical properties were similar to those of the Tobacco sulphate pulp.The bleaching test was carried out for the Tobacco semichemical pulp by the applying of three stage bleaching with chlorine compounds. The brightness value of 75 to 80 were obtained in the case of the treatment with the total available chlorine of 10% to 13% and the use of less NaOH than 1% in alkaline extraction.Three stocks, i.e. Tobacco stem, root and whole stalk, were pulped respectively at the same condition by two methods, i.e. sulphate and semichemical processes. It became obviously that the pulp from root tended to form a weaker and softer paper than that from stem. However, in comparison between the stem pulp and the whole stalk pulp, the differences in yield, beachability and mechanical properties were not so large that in practical sense, the presence of root would not be affected on the quality of pulp if the washing of chip or the cleaning of pulp was inforced fully.