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Austria What are the paint defoamer for paints(1)



Austria Selection of antifoaming agents for different applications:

Flat coating


Features: Low viscosity, low defoaming pressure

Recommendation: Mineral oils or mineral oil modified polyethers

Elastic coating

Features: High viscosity, high paint defoamer pressure

Recommendation: Polyether modified silicone

Surface coating and film covering adhesive

Defoaming agents are widely used in food industry, paper industry, water treatment, oil extraction industry, printing and dyeing industry, coating industry, detergent industry, rubber latex industry, aerosol industry, daily chemical industry, pharmaceutical industry, dairy industry, etc. [2]

Recommendation: Polyethers, which can effectively prevent surface defects and have a small impact on gloss

Defoamer is an additive for eliminating foam. A large amount of foam will be produced in the production and application process of coatings, textiles, medicine, fermentation, paper making, water treatment, petrochemical and other fields, which will affect the product quality and production process. Based on the inhibition and elimination of foam, a specific amount of defoamer is usually added to it during production

Water in Water Colorful






Action mechanism of polysiloxane defoamer
The representative defoaming mechanisms of polysiloxane mainly include "bridging spreading" mechanism, "bridging dehumidifying" mechanism, and "spreading liquid entrainment" mechanism. The "bridging spreading" mechanism mainly starts from the basic point of "polysiloxane has a relatively low tension and is easy to spread on the liquid film." It emphasizes that defoamer droplets are prone to deformation, but this theory cannot explain the defoaming differences between individual polysiloxanes and mixtures of polysiloxanes and solid ions as defoamers. The "bridging dehumidification" mechanism is mainly based on the hydrophobicity of polysiloxanes themselves, but the defoaming effect of polysiloxanes with high viscosity cannot be well explained. The "spreading liquid entrainment" mechanism cannot be confirmed because some facts indicate that polysiloxanes sometimes do not spread on the surface of the foam film, but can also break the foam.

Features: More surfactants, stable foam

Austria Recommendation: Use polyethers or mineral oil to modify polyethers

Precautions for use of paint paint defoamer:

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