Views: 2 Author: Site Editor Publish Time: 2021-09-15 Origin: Site
The pulp produced by chemical and mechanical methods is called natural color pulp, which is usually yellow or brown. In order to meet the requirements and aesthetics of the paper we use, we need to bleach the pulp. Bleaching is to use a suitable bleaching agent. Oxidation, reduction, or decomposition are required to precipitate lignin in the pulp, or fade, and make the pulp white. Today, Shandong Yisitai Paper Machinery Co., Ltd. will take you to learn about several methods of bleaching used in the pulping of paper mill machinery equipment.
1. Oxidative bleaching method uses oxidative bleaching agents, such as hypohydrogen salts, to destroy the structure of lignin and dissolve it to achieve the purpose of improving the whiteness of pulp. However, this kind of hydrogen-containing bleaching agent is relatively polluting to the environment. , So it is gradually replaced by oxygen-containing bleaching methods.
2. Reduction bleaching method, which uses reducing bleaching agent to change the structure of the chromophore group and decolorize it. It is more suitable for the bleaching of high-yield pulp such as ground wood pulp and chemical machinery because it will not cause fiber composition. It can maintain the characteristics of the original slurry. However, the stability of the whiteness of the paper made by this bleaching method is relatively poor, and the original color will be restored after a period of light.
The above is the bleaching method shared by Shandong East paper mill machinery Company. Each of these two bleaching methods has its own advantages and disadvantages. The specific use depends on the situation. The above sharing can be used as a reference. If you have other questions, you can also contact us for consultation.