In the process of papermaking, a large amount of foam is prone to appear in the pulp, which will affect the quality of the paper and reduce the effect. The foam can be defoamed by adding a paper pulp defoamer. This article analyzes the causes of foaming and stability of paper pulp, and gives solutions for defoaming.
The reason why paper pulp is easy to foam and stabilize
Foam is a dispersion system in which the gas phase is dispersed in the liquid phase. The gas phase is free air and the carbon dioxide liquid phase is water. The formation of foam is due to the presence of surface-active substances in the liquid phase (water). If there is no surface-active substance in the water, even though the foam is formed, it will not be stable, and will quickly collapse on its own.
1. Reasons for foaming: In the pulping and papermaking process, if there are fatty acid soap, rosin soap and lignin derivatives in the pulp, or the pulp contains remaining sulfite waste liquid, sulfate waste liquid or its residual alkali and washing If it is not good or the slurry is added with sizing agent, retention and drainage aids and other chemicals, it is possible to form a relatively stable foam.
The characteristic of these types of substances is that their molecular structure is asymmetry. The molecule is composed of a polar part and a non-polar part. The polar part is hydrophilic and the non-polar part is hydrophobic. The polar part of the foam is in the water, while the non-polar part is in the air.
2. Reasons for foam stability: From the point of view of colloidal chemistry, this type of surface active material acts as a stabilizer. The main reason is that this type of surface active material can reduce the surface tension of the liquid. The surface tension is low, and the energy required to form a new interface is small. Therefore, the same work of moving the gas into the paper material system allows the formation of a larger surface area, resulting in more small foams. Small foams have greater stability than large foams; therefore, in waste liquid treatment or pulping In the papermaking process, these small foams are particularly difficult to remove due to the presence of such surface-active substances, which act as a stabilizer.
(Picture: Paper pulping defoamer)
Paper pulp defoaming plan
In the process of papermaking, due to the fact that the raw materials in the pulp contain surfactant substances, it is easy to produce a large amount of foam. Paper pulp foam will affect the quality of paper and affect production efficiency. The harmful foam can be eliminated by adding defoamers.
The Nanhui defoamer manufacturer has developed and designed the paper pulp defoamer for paper pulp which is prone to foam and stable. The defoaming agent for paper pulp has fast defoaming and good foam suppression. Adding to the paper pulp can quickly disperse and reduce the surface tension of the system. It can be quickly dispersed in water to eliminate foam.
Nanhui metalworking fluid defoamer is added in the production, which can control the foam from the production source, optimize the formula of the metalworking fluid, reduce the surface tension of the system, and reduce the foaming power. The defoaming agent can also be added during the use of metalworking fluids, generally about three thousandths of the foaming system. The addition amount is small, which can quickly defoam the foam and inhibit foam regeneration for a long time.
The source manufacturer of Nanhui defoamer can solve various industrial foam problems in a targeted manner. If you encounter bubble problems in related industries, you can call Nanhui technical specialist Yoyo +86 134 28601010
