Evaluation of mulberry plant as a pulping raw material

Abstract

In this paper, a complete chemical analysis of the mulberry plant was performed to evaluate the differences in its chemical composition in relation to plant age. The mulberry plant is characterized with moderate cellulose, lignin, and pentosan. Plant age (from 8 to 12 months) increased cellulose content from 42.0 to 42.8 % and decreased total lignin content from 26.0 to 23.3 %. Extractive contents also decreased with plant age. Kraft and soda-AQ pulping processes were also evaluated for 12-month-old mulberry plant. The mulberry plant was very difficult to delignify and needed drastic cooking conditions. To achieve kappa number 25, 18 active alkali charges was needed for 3 h of cooking. At this kappa number, the kraft process showed slightly better pulp yield. The physical properties of the mulberry plant pulp were similar to hardwood pulp. Kraft process showed a slightly better tear index. Blending of the mulberry plant pulp with longer jute fiber pulp increased the tear index significantly.