Role of Fluorescent whitening agent in paper industry

General pulp fiber after a certain method to remove most of the lignin, but there is still a very small amount of lignin and other pigments, so that the pulp with a slight yellow or gray. The whiteness of pulp can be improved by chemical bleaching, adding dyes or pigments, but these methods are limited. Intense bleaching in the pursuit of whiteness will damage the strength of the pulp fibers. After the use of fluorescent whitening agents in the paper industry, it is relatively easy and convenient to produce highly whitened paper by a combination of bleaching and whitening.

The whitening principle of fluorescent whitening agent in pulp, paper surface sizing and surface coating is the same. Its whitening effect is mainly manifested in the following two aspects:

1. Offset the yellowness of the paper fiber, which can significantly improve the whiteness of the pulp fiber bleached with chemicals.

2. It can eliminate the yellow appearance of binder, filler, binder and auxiliary agent, and improve the whiteness of white pigment

Due to the optical whitening effect of fluorescent whitening agent can significantly improve the whiteness of paper products, and make it bright and pleasing to the eye, and will not make the pulp caused by chemical fiber consumption, less consumption, easy to use, play any bleach and other dyes can not achieve the role. Therefore, the use of fluorescent whitening agent has become an important means to improve the whiteness of pulp after chemical fiber bleaching, widely used in the whitening treatment of paper with high whiteness requirements.