The formation of bubbles in coatings and the principle of foam stabilization
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In the production process of coating, air will be drawn in to form bubbles. Some raw materials such as surfactant and dispersant will make bubbles stable.
In the coating construction process will also produce bubbles, which mainly depends on the coating construction method. For example: curtain coating can continuously involve air in the coating, airless spraying is also easy to involve air, and spray construction under relatively low humidity or high temperature conditions is easy to generate bubbles.
Foam stabilization principle:
Malangeni effect (Surfactant induced liquid reflux, counteracting gravity)
Electrostatic effect: the electrostatic repulsion of surfactant makes the liquid film of bubble thicken, so as to stabilize the bubble.
