Study on TCF Bleaching of Reed Displacement Cooking Pulp

With the improvement of environmental protection requirements, paper-making enterprises are imperative to eliminate pollution directly in production. This paper aims to adopt environment-friendly bleaching method, yield good quality pulp products. Op-Pa-P bleaching process of reed displacement cooking pulp is studied in this paper (O-oxygen, P-hydrogen peroxide, Pa-peracetic acid ). The experimental conditions of Op and Pa stage were optimized respectively. It included oxygen pressure, temperature, time in Op stage and charge of peracetic acid, temperature, time in Pa stage. The results show that the optimal technological conditions of Op are: 0.9Mpa, 100°C, 70min, Op stage can make brightness increase by 57.3%, viscosity decrease by 25% and KMnO₄ number reduce to 2.6. Pa stage optimal conditions are Pa charge 1.5%, 70°C, 75min, brightness reached to 79.1 %ISO, KMnO₄ number to 1.0, viscosity to 631mL.g^-1. The brightness of P bleached pulp reached to 84.8%ISO, viscosity 601 mL.g^-1, KMnO₄ number 0.8.