The action principle of coating defoamer


Release time:

2016-08-19

Author:

New Earth Group

Source:

The action principle of coating defoamer

Coating is now a very important surface decoration in home decoration and furniture, so it is also very important for its quality. During the production and construction of the coating, bubbles will be generated due to the inflow of air due to stirring. The coating defoamer is a defoamer made according to the foaming principle of the coating defoamer. Now I will give you a detailed introduction.
 
1, bubble generation and stable bubble principle: in the production of paint, will be involved in the air and the formation of bubbles, and the resulting raw materials such as: surfactants and dispersants will make the bubble stability.
Bubbles are also produced in the construction process of the paint, which mainly depends on the construction method of the paint. For example: curtain coating can be continuously involved in the air in the paint, airless spraying is also easy to involve the air, in relatively low humidity conditions or under high temperature conditions for spraying construction is easy to produce bubbles.
Steady bubble principle:
Marangoni effect (surfactants cause reflux of liquids that can counteract gravity)
Electrostatic effect: The electrostatic repulsion of the surfactant thickens the liquid layer of the bubble, thereby stabilizing the bubble.
2. The action principle of coating defoamer
The defoaming agent can be in the unformed stage of the foam or after it is formed: after the addition of the defoaming agent, the uniformly dispersed defoaming agent will penetrate into the foam elastic film and distribute in the foam film, and the reduction of the surface tension will lead to the rupture of the thin layer.
The uniformly dispersed defoaming agent penetrates into the foam thin layer and forms a monomolecular film, which reduces its adhesion and is easy to break the thin layer.
The defoaming agent containing hydrophobic particles possesses a third mechanism. These kinds of hydrophobic particles begin to adsorb the surfactant at the top of the thin layer upon reaching the surface of the thin layer. The foam breaks due to the gradual disappearance of the surfactant.

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