Tonga What are the No Foam for paints(2)
Attenuation mechanism of foam
Under the condition of gravity and pressure difference, the liquid membrane of foam will flow and discharge liquid unevenly, and the gas in the bubble will continue to diffuse and permeate due to the different pressure difference on both sides of the bubble membrane, so the instability of foam itself is mainly reflected from the dynamics. [4]
The attenuation mechanism mainly includes the diffusion of gas through the liquid film and the discharge of liquid from the liquid film. These two properties are inherent attributes of foam itself, and have nothing to do with the existence of surfactant. However, these two attenuation mechanisms only play an obvious role in the initial stage of foam system formation. With the attenuation of foam system, these two effects gradually weaken, making the foam attenuation rate gradually slow. [
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Precautions for use of paint No Foam:
Before use, stir thoroughly and mix evenly; Adding the paint while stirring; Before use, it is generally not diluted with water; The dosage should be appropriate. Excessive dosage can cause shrinkage, edge shrinkage, poor brushing performance, and other problems; Too little dosage leads to poor defoaming effect; Add it in two stages, namely, add it in the grinding stage and the paint mixing stage, generally accounting for half of the total amount each time. Use defoaming agents with good foam suppression effect in the grinding stage, and use defoaming agents with good foam breaking effect in the paint mixing stage