Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Delignification of refiner mechanical pulps from Albizia lebbek and Eucalyptus hybrid by sulphate process.

Abstract

Barked wood of Albizia lebbek and Eucalyptus hybrid [E. tereticornis] was chipped and refiner mechanical pulp prepared by passing chips soaked overnight in water through a 30-cm laboratory disc refiner (the Sprout Waldron disc refiner) at 30 mil, followed by further refining at 5 mil. Unbleached screened pulp yields were respectively 94 and 93%. The pulp was then treated by the sulfate process using 6-14% NaOH + Na2S, with a material/liquor ratio of 1:4, sulfide 25%, temperature 162°C and cooking time 3 h. Data are presented on the resulting pulp unbleached yields and strength properties (burst, tear and tensile indices). The results showed that 8% NaOH + Na2S gave high yields (around 60%) with strength properties almost equal to those of kraft pulp (yield 45%). The results were also better than those obtained in previous tests of delignification of refiner mechanical pulp using the soda process.