Paper defoamer is a product designed for the foaming characteristics of papermaking processes in the paper industry. It can effectively control the overflow of foam in pulp, improve the quality of paper making, and is widely used in paper making system, sewage treatment, antifreeze and defoaming of distillation system.

In the paper making process, the foam in white water mainly comes from a variety of chemical additives added in the beating process, such as filter aid, retention aid, wet strength agent and sizing agent. These additives are prone to generating bubbles during the beating and closed cycle of white water, while the fine fibers and pigment fillers in the slurry provide adsorption carriers for the bubbles. When there are too many bubbles in the slurry, these bubbles are easy to merge into large bubbles, float on the liquid surface, and form the liquid surface foam we usually see.

The types of paper defoamers mainly include kerosene, oil esters, fatty alcohols, polyethers, and organosilicon. These different types of defoamers have their own characteristics in solving the foam problem in the papermaking process and are suitable for different application scenarios. For example, kerosene defoamers are mainly used to eliminate foam on the water surface, but their ability to remove gas in the slurry is poor, and will affect the sizing effect, making the finished paper with kerosene smell, which is usually only used for low-grade paper such as corrugated paper. Fatty alcohol defoamers have gradually become the mainstream choice in high-end paper production due to their high efficiency and low impact.

The role of paper defoamer is not limited to the elimination of foam, it can also reduce paper breaking, avoid the formation of holes, improve the speed of paper machine and the strength of paper web, improve the one-way retention rate of filler, reduce the concentration and ash content of pulp on the net, extend the life of forming web, and improve the smoothness, opacity and evenness of paper, thus improving the overall quality of paper.

In practical applications, papermaking defoamers can be directly added to the system to be defoamed through a drip pump, or diluted before use. When using defoamers, the appropriate type and amount should be selected based on specific process conditions and defoaming requirements.