Slurry in the paper industry is a mixture of various substances. During the storage, flow and production of the slurry, a large amount of air is drawn into the slurry due to the presence of agitation, turbulence, oscillation and jetting operations.
Air entering the slurry is surrounded by the surrounding slurry to form bubbles. In this case, it is necessary to solve the foam problem, and it is necessary to use a paper-making defoamer to eliminate foam. The paper-making defoamer is polymerized from alcohol, polyether, fatty acid amide and other small substances, which can effectively control the overflow of foam in the pulp. problems and improve papermaking quality.
In the defoaming process of the defoaming agent for papermaking, the molecules of the defoaming agent will be adsorbed on the bubble film and then enter the liquid film between the bubbles. After further diffusion in the liquid film, the defoaming agent molecules will become part of the liquid film after entering.
In this case, there are two functions: one is to expand the defoamer on the original surface film into a repeating film to replace the foaming material on the surface film, so that the two films are tightly combined with the liquid in the extruded film. Finally, the papermaking defoamer enters the film and causes the foam to burst. The other is to form a repeating film on the surface film, which can reduce the inner surface tension of the bubbles and thereby increase the curvature of the bubbles and further reduce the thickness between the liquid films. In this way, the liquid film becomes thinner and the papermaking defoamer safely enters the middle of the thinned liquid film and finally the foam bursts. The second is that an emulsion can diffuse rapidly in water.
