Pulping of gamari roots (Gmelina arborea)

Abstract

Gamari (Gmelina arborea) is planted for pulpwood in allocated forestland in Bangladesh. After harvesting of pulpwood roots are burnt in the land for re-cultivation. But the root is similar to wood. This root can be a supporting raw material in the pulp mill as mills are facing challenge to collect raw material. No study has been reported on the physical, chemical and morphological characteristics and its pulping. In this paper, gamari wood roots are characterized physically, chemically and morphologically. The α-cellulose content in gamari roots and stem was 37.0 and 43.2% and lignin content was 30.0 and 24.8%, respectively. Kraft pulping of gamari roots and stem was also carried out by varying operational parameter. Gamari root was difficult to delignify. A higher active alkali charge was required to delignify. Pulp yield was 37.8% for gamari roots and 44.2% for rubber stem with kappa number 33.1 and 21.4, respectively, at the active alkali charge of 20%. Without affecting pulp yield and kappa number 25% root could be mixed with wood chips. Papermaking properties mixed cooked pulp were close to wood chips pulp.