Some alkaline cooking processes were applied to obtain the pulp from Tobacco stem in laboratory scale, and the physical properties of those Tobacco pulps were investigated.
The cold soda pulps were produced at the comparative low yield between 64% to 67% with the immersion for long time. The defibration and refining of immersed chips were carried out in the Lampen mill and the small beater, but the fine shieves remained considerably in abundance after the pulps were bleached.
The washed and air-dried chips were cooked with the various amount of sodium hydroxide. The consumption of alkali was slightly low level as compared with the common case of alkaline pulping of wood. The soda pulp having brightness value of 70 could be easily obtained by the usual process; for example, the combination of the cooking with 16.4% active alkali and the single stage hypochlorite bleaching with 10% available chlorine. Excepting the conditions of cooking and bleaching, the wire mesh of screen for the pulp washing and the decay of Tobacco stem were distinctly the affecting factors on the yield and properties of pulp.
The washed chips were cooked with 19.5% active alkali at the various temperature by the sulphate process. The cooking temperature had relatively little effect on the strength properties of pulp, although the yield of pulp tended to decrease with increasing temperature. The sulphate pulp having brightness value of 73 was obtained at the yield about 38% by the two-stage bleaching with sodium chlorite and calcium hypochlorite.
It is concluded that the manufacture of the peculiar papermaking pulp from Tobacco stem can be possible by means of selecting the suitable condition. The papers from Tobacco stem pulps have generally such the character as high density and low opacity, and in the strength properties they are similar to the hardwood pulp of good quality.
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