Pulping and papermaking potential of six mangrove species in Bangladesh

Abstract

In this paper, physical, morphological and chemical characterizations of the six main mangrove species of Bangladesh [namely Keora (Sonneratia apetala), Gewa (Excoecaria agallocha), Bine (Avicennia alba), Sundari (Heritiera fomes) Pashur (Xylocarpous mekongests) and Kakra (Bruguiera gymnorhiza)] were discussed in order to assess the suitability of pulping raw materials. The wood density of these six mangrove was found to be 0.5–0.6 g cm−3 except Gewa which had 0.39 g cm−3. The fiber length of these species was varied from 0.74 to 1.2 mm that was considered as short fiber. Sundari contributed the longest fibre length (1.2 mm) among these six species. The chemical results revealed that these species contain high percentages of dichloromethane, followed by methanol extractives. Methanol extracts in Pashur, Sundari and Bine was higher than 10 %, which indicates high percentage of tannin material. These species were characterized with high lignin content and low α-cellulose content. The pulping of these six mangrove species was also carried out by kraft process and papermaking properties were also evaluated. Pulp yield was lower and kappa number was higher as compared with other tropical hardwoods. But the physical properties of these species were quite acceptable. Considering pulp yield, kappa number and physical properties, it may be concluded that Keora and Gewa can be used as kraft liner and other packaging grade paper pulp.