Kraft pulping of Albizia richardiana wood species in a mixture with Bambusavulgaris.

The use of wood along with bamboos is now new a dimension of research for decreasing the raw material crisis in pulp industry to run the mill to its full daily production capacity. With this aim, kraft pulping of Albizia richardiana (rajkoroi) wood species in a mixture with Bambusa vulgaris (baizzya) was assessed to incorporate the former species as pulping raw material. Chemical analysis showed that alphacellulose content of B. vulgaris is low but lignin content is high compared to A. richardiana. Pulps were made in kraft process maintaining 25% sulphidity by varying the alkali doses. The temperature was maintained at 170°C during pulping. The chip in the mixture were in the ratio of B. vulgaris : A. richardiana (100:00; 70:30; 50:50; 30:70 and 00:100). Hand sheets were made and the physical strength properties likely tear, tensile and burst were evaluated at two freeness level. The active alkali requirement for bamboo was higher than A. richardiana for same degree of delignification. The pulp yield was low but superior quality pulp could be obtained from B. vulgaris. On the other hand pulp yield for A. richardiana was high but quality was low. Mixing of B. vulgaris chips in a proportion of 30%, pulp yield decreased but strength properties like tear, tensile and burst increased. On further increase of bamboo chips in the furnish, a similar trend was observed. The optimum ratio of chips of B. vulgaris: A. richardiana could be either 30:70 or 50:50 based on pulp yield and quality. The pulp making characteristics of the two species being different, further research on blending the pulps together after individual cooking of the species is recommended. [ABSTRACT FROM AUTHOR]