EFFECT OF NONIONIC SURFACTANTS ON CMP PULPING OF 6-YEAR-OLD POPLAR WOOD

摘要

In order to improve the penetration of pulping liquor in to the wood chips and CMP pulping process, the effect of three non-ionic commercial surfactants, PEG-1000, KELA-2 and KECA-20 at four levels of 1, 2, 3 and 4% were investigated on the CMP pulping of 6year-old poplar wood as digester additive. The resulting pulps with higher screen yield and lower reject from application of each surfactant as well as the reference CMP pulp (without surfactant) were bleached in two-stages H2O2 bleaching after chelating stage with DTPA. The pulping and bleaching results showed that application of all surfactants increased accept yield and brightness of pulps and reduced the consumption of bleaching chemicals, opacity, and yellowness of pulps compared to the reference pulp. The best result was obtained with PEG-1000 (4%) with increasing accepted yield by 1.2%, brightness by 2% and decreasing screen reject by 1%. KELA-2 (2%) increased accepted yield and brightness by 0.68% and 1.9%, respectively. KECA-20 (1%) decreased screen reject by 0.87% and increased accepted yield and brightness by 1.14% and 0.5%, respectively. In addition, the handsheet papers obtained with surfactants addition to CMP pulping liquor had better strength properties compared to reference paper. The results also indicated that the addition of surfactants resulted in lower post color number and higher brightness stability of CMP pulps. The significant improvement in strength properties of the pulps were attributed to the development of bonding capacity between fibers due to uniform pulping, and lower extractives content. The results indicated the promising potentials of the non ionic surfactants for the CMP pulping of short rotation poplar wood.