Title
Mixed cooking of bamboo with hardwood
Authors
M. SARWAR JAHAN MAMON SARKAR and M. MOSTAFIZUR RAHMAN

Received August 31, 2015
Published Volume 51 Issue 3-4 March-April
Keywords bamboo, Trema orientalis, mixed cooking, bleaching, pulp yield, kappa number

Abstract
Bamboo is the main fibrous raw material for pulping in Bangladesh. Recently, Trema orientalis has been found as the fastest growing wood species suitable for pulping. However, the basic wood density of T. orientalis is low, which consequently decreases digester yield. On the other hand, basic wood density of bamboo is quite high. Optimum pulping conditions of these raw materials were similar. Therefore, mixed pulping of T. orientalis with bamboo can compensate digester yield. In this study, bamboo and T. orientalis chip mixtures were kraft cooked and the resulting pulp and paper properties were investigated. Cooking was carried out for five different chip mixtures (0, 25, 50, 75 and 100%). Pulp yield was increased and kappa number decreased with increasing T. orientalis proportion in the fiber mixture. The tensile index of the produced pulps was increased with increasing the proportion of T. orientalis in the chip mixture. The maximum tensile-tear was obtained for the 50:50 chip mixture. Bleaching was carried out by ECF sequences, and the bleached pulps were beaten in a PFI mill, and then tested for optical and physical properties. All pulps showed almost similar bleachability. Final pulp reached an 80% brightness level at ClO2 consumption of 25 kg/ton of pulp.