Optical brightener ≠ bleaching agent. In the papermaking industry, optical brightener cannot replace bleaching agent to bleach pulp, but is used as a complementary color brightening agent for bleached pulp.
The whitening principle of optical brightener is to absorb the invisible ultraviolet light in the product and reflect the complementary visible fluorescence to achieve the effect of whitening and brightening the product.
The pulp of most papermaking manufacturers contains more lignin and other pigments. If it is not bleached with bleaching agent, the direct use of optical brightener cannot achieve a good whitening and brightening effect.
Optical brightener can only be used for whitening bleached pulp, and the higher the initial whiteness of the pulp, the better the whitening effect.
Many of our papermaking customers have found through practice that the use of optical brighteners in unbleached pulp or groundwood pulp can only improve the color light, and the whitening effect is minimal.
After a lot of experiments by application engineers, our company bleached straw pulp with an initial whiteness of 49.7% with hypochlorite to a basic whiteness of 64.8% and 73.3%, and then added the same amount of optical brightener under the same experimental conditions, and obtained the influence of the basic whiteness of paper pulp on the whitening effect of optical brightener:
The higher the basic whiteness of paper pulp, the better the whitening effect of optical brightener and the greater the whitening range.
At the same time, after bleaching, the pulp should be washed and purified to reduce the influence of residual chemicals such as acid, alkali, chlorine and other impurities in the pulp, give full play to the whitening effect of optical brightener, and obtain the best whitening effect.
Bleaching paper pulp to a whiteness of more than 70% and then using Hongyi Chemical APC-X optical brightener can increase the whitening effect of pulp to more than 95% standard whiteness.
Tongge optical brightener APC-X is a special product with high whitening strength and strong applicability specially designed for papermaking customers.
Many manufacturers on the market are now using traditional whitening agents, which not only add a large amount, but also do not significantly improve the whitening effect.
Tongge Chemical has made corresponding improvements to different types of fluorescent whitening agents based on the requirements and feedback from customers in different industries, and provides application technical support for every customer.
For more questions about fluorescent whitening agents, please feel free to contact us!
