Bleaching process of bamboo pulps processing

A dissolving pulp suited for production of acetate and Lyocell fibers was prepared with bamboo,and the bleaching process was studied.The results showed that the optimal effect can be obtained when the dosage of xylanase is 0.04% in the enzymatic pretreatment.Dimethyloxirane(DMD) can oxidize lignin selectively and enhance H_2O_2 bleaching.The optimal delignification and assistant bleaching effect of DMD are found when the mass ratio of acetone and hydrogen potassium persulfate is(3∶4).In these two pretreatment stages,the decrease of Kappa number accounted for 37.9% of the total decrease in the entire bleaching process,while the decrease of intrinsic viscosity only made up 13.7%.X-ray diffraction proved the delignification of DMD for bamboo pulp.DMD treatment resulted in the decrease of crystallinity and crystallite size of bamboo pulp during bleaching.However,its crystallinity and crystallite size increased in other stages of bleaching.