STUDY OF RESPONSE OF ACACIA MEARNSII TO HIGH YIELD PULPING

Abstract

Chemimechanical pulping characteristics of young plantation — grown Acacia mearnsii were investigated at different chemical compositions in preimpregnation stages and at different time and temperature in cooking stages. The results were compared with those obtained from Eucalyptus and other hardwoods. In general Acacia meransii produced pulps that were comparatively inferior in physical and optical properties compared to those made from Eucalyptus and other hardwoods. It was found that, the maximum tensile strength was obtain when chips were treated with 5% as NaOH followed by 30 min cooking at temperature 175°C prior to refining. The chips were refined in refiner with single rotating disc of 12 inches diameter and it was observed that 3 pass with decreasing clearance gave better results. The CMP pulp was bleached by two stage Hydrogen peroxide bleaching and brightness up to 67% was obtained in single stage. It was observed that brightness enhancement takes place using second stage bleaching up to 68%.