Application method for cationic starch

Abstract

The invention provides an application method for cationic starch. Cationic starch is added behind a pressurized screen for papermaking. Concrete steps of addition are 1) starch pasting and 2) dilution of the pasted cationic starch with clear water until a mass percent is 1.5 to 2.5%, maintenance of a temperature at 60 to 70 DEG C and on-line addition of the pasted cationic starch behind the pressurized screen in process flow. The application method has the advantages that the purpose of increase of the single-pass retention rate of pulp is achieved and production cost is reduced.

Description

technical field [0001] The invention relates to an improvement of a papermaking process, in particular to an application method of cationic starch. Background technique [0002] The traditional cations are added to the thick pulp in the pulping section such as the mixing tank and the head box, which is not good for the retention of the pulp and filler. Especially when the pulp is not clean and the content of impurity particles is large, the retention of cations on fillers and pulp is worse, and a large amount of pulp and papermaking chemicals are discharged with white water, resulting in increased consumption and cost of the paper mill. In addition, the traditional cation addition process has the defect of low retention due to the self-existence of cationic starch. A large amount of starch enters the papermaking system with white water, accumulates too much during the recycling process, increases the nutrients in the system, and breeds a large number of bacteria, resulting i...

AI Technical Summary

Problems solved by technology

[0002] The traditional cations are added to the thick pulp in the pulping section such as the pulping tank and the head box, which is not good for the retention of the pulp and fillers.

Especially when the slurry is not clean and the content of impurity particles is large, the retention of cations on fillers and slurry is worse, and a large amount of slurry and papermaking chemicals are discharged with white water, resulting in increased consumption and cost of the paper mill

In addition, the traditional cation addition process has the defect of low cationic starch self-survival, a large amount of starch enters the papermaking system with white water, accumulates too much in the process of recycling, the system nutrients increase, and a large number of bacteria breed, resulting in system imbalance.