TCE bleaching technology for sulfate pulp of growing poplar by biological chemical method

Abstract

The invention discloses a TCE (Total Chlorine-Free) bleaching technology for sulfate pulp of growing poplar by biological chemical method. The technology comprises the following steps: (1), cooking: getting fast-growing polar pieces; putting the fast-growing polar pieces into a distilling pan for cooking, so as to obtain primary pulp, and then washing and screening the primary pulp to obtain paper pulp; (2), pre-treating the paper pulp with xylanase; (3), TCE bleaching: bleaching the paper pulp pre-treated with the xylanase, wherein the bleaching process is one of OP-Q-P, O1-O2P-Q-P or O1P-O2P-Q-P. According to the TCE (Total Chlorine-Free) bleaching technology for sulfate pulp of growing poplar by biological chemical method, the xylanase is adopted to pre-treat the paper pulp, then one of the bleaching processes OP-Q-P, O1-O2P-Q-P or O1P-O2P-Q-P is adopted for bleaching, so that the paper pulp with higher whiteness and viscosity is obtained; compared with the paper pulp obtained through directly bleaching without xylanase pre-treatment, the paper pulp provided by the invention has the advantages that the loss value of whiteness is lesser, the folding strength is higher 45 times averagely, the bursting index is higher 0.45 N*m*g <-1> averagely, the breaking length is higher 0.35 KM, and the tearing index is quite. The beating revolution number is lesser when the paper pulp reaches the same or similar beating degree, and the 20% of beating energy consumption can be saved approximately.

Description

technical field [0001] The invention relates to a kraft pulp biochemical TCF bleaching process of fast-growing poplar, belonging to the technical field of papermaking. Background technique [0002] Fast-growing poplar is the main tree species used in forestry-paper integration construction in northern my country. It belongs to fast-growing broad-leaved wood. They have fast growth, strong adaptability, high natural whiteness, loose material, good absorption of liquid medicine, and relatively high lignin content. Low, high content of cellulose and hemicellulose, can be used to produce chemical pulp, semi-chemical pulp and mechanical pulp, etc., is one of the main high-quality papermaking raw materials in northern my country. Fast-growing poplar is widely planted in northern Europe, North America and northern my country. It includes many varieties, representative ones are black poplar, triploid poplar, and Zhonglin poplar. The growth characteristics and composition of these fast...

AI Technical Summary

Problems solved by technology

[0003] In recent years, high-yield pulp has developed rapidly, but high-yield pulp has disadvantages such as high energy consumption for refining, low pulp strength, poor whiteness stability, and easy yellowing, which makes it difficult to make some paper products from high-yield pulp. High strength, not easy to yellow, good thermal stability paper

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