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Source of Foam in the Paper Industry

Apr 22, 2019

The foam in paper white water mainly comes from many chemical additives added to the slurry tank during the pulping process, such as filter aids, retention aids, wet strength agents, sizing agents, etc., which are in the process of beating and white water closed cycle. It is easy to generate bubbles.

Since the slurry contains very fine fibers and pigment fillers, these solid materials provide a carrier for the adsorption of bubbles. Depending on the fibers, some adsorb to the surface of the fibers, some penetrate into the interior of the fibers, while fine pigments And the filler is easily agglomerated on the surface of the bubble, enhancing the strength of the foam. Of course, some fine bubbles are not queued in the slurry. When the content of bubbles in the slurry is large, the bubbles are easily combined, and the small ones are merged into large ones. The large bubbles are easily floated on the liquid surface due to the small density, which is the liquid level foam that we usually see. The fine foam adsorbed on the fibers in the slurry, the foam on the liquid surface is larger.

The production of liquid level foam may also be that the slurry is not cleaned, the fiber is not fully inflated, the slurry falls in a waterfall, the air leaks from the slurry pump, etc., and a large amount of air is mixed into the water to generate foam and the like.

In general, pure water and pure surfactants do not blister because their surfaces and interior are uniform, and it is difficult to form an elastic film, which is unstable even if it is formed, and disappears instantaneously. However, there is a surfactant in the solution. After the bubble is formed, the hydrophilic group and the hydrophobic group in the molecule are adsorbed by the bubble wall due to the intermolecular force, forming a regular arrangement, and the hydrophilic group faces the water phase, and is hydrophobic. The base faces the inside of the bubble, thereby forming an elastic film at the bubble interface, which is highly stable and is not easily broken under normal conditions. The stability of the foam is related to surface tack and elasticity, repellency, movement of the surface film, temperature, evaporation and the like. Furthermore, the bubble is inversely related to the surface tension of the liquid, and the smaller the tension, the easier it is to foam. In the life and production, sometimes the appearance of bubbles brings a lot of inconvenience to people, so it must be defoamed.


Contact:Sharon Song(Sales manager)

Zhejiang Runhe Organosilicone New Material Co.,Ltd(Factory)

Zhejiang Runhe Chemical New Material Co.,Ltd(Exporter)


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