MEDIUM CONSISTENCY LESS-POLLUTION BLEACHING OF HEMP CORE KRAFT PULP

摘要

In this study, the multi-stage bleaching of hemp core kraft pulp containing oxygen (O), hypochlorite (H), EDTA (Q) and hydrogen peroxide (P) bleaching process were investigated. The effects of chemical charge, temperature, retention time and pressure on pulp properties were studied in order to maximize the brightness gain at lowest viscosity loss. Under the selected conditions, only 3% active chlorine charge was needed to obtain the pulp with brightness of 85% ISO, which was far lower than conventional CEH bleaching. And the tensile index of the bleached pulp was 55.3 kN m/kg and the tear index was 5.4 N m~2/kg, respectively.