Most of the paints use vegetable oil as the main raw material, which is called paint. Now synthetic resin has mostly or completely replaced vegetable oil, so it is called paint. But foaming in the paint requires attention. At the construction site, it will be found that the paint produces foam. The surface that is heated due to direct sunlight, the paint film loses adhesion in some places, and the phenomenon of bubbling due to separation from the surface of the substrate affects the appearance and is easy to fall off. Therefore, we need a
paint defoamer. to eliminate.
Types and composition of paint defoamers:
Water-based paint defoamer is a compound product of organic polyether ester, mineral oil and alcohol, which will not produce surface defects or affect film-forming properties, and has special effects on water-based paint systems.
Oil-based paint defoamer is compounded with special modified polyether through a special process. It is especially suitable for defoaming oil-phase foaming systems. The product has good stability; it has good compatibility with organic hydrocarbons. The system does not affect the transparency of the product; it has certain leveling performance. It can be widely used in the elimination and suppression of foam in various harsh systems in a wide temperature range.
The polyether defoamer enters the foam system in the form of particles. When the foam is about to break out, the defoamer particles in the system can quickly destroy the elastic film of the bubbles and inhibit the foam from happening.
Polysiloxane defoamers will not produce pinholes, spots and fish eyes in water-based coatings, and have the characteristics of fast defoaming speed and good compatibility.
Silicone oil has a special chemical structure and is neither compatible with water or substances containing polar groups, nor is it compatible with hydrocarbons or organic substances containing hydrocarbon groups. Moreover, silicone oil is not compatible with various substances, so it has a wide range of applications, not only in water system for defoaming, but also in oil system.
Non-silicon defoamer is a high-carbon alcohol ether emulsion type non-silicon defoamer that completely does not contain silicone. It is mainly produced from hydrocarbon compounds and high-carbon alcohol esters through special processes.
Coating defoamer selection considerations:
First of all, you have to consider whether the defoamer system is suitable for your industry. Because defoamers are oily and water-based, different defoamers are used in different industries.
Second, you need to consider how much alcohol or organic solvent is in the system. Because alcohol has a defoaming effect is the consensus of everyone, therefore, sometimes there will be some interference.
Finally, the applicable PH range of the defoamer, strong acid and strong alkali environment have relatively strict requirements on the defoamer, which needs to explain the carrier environment with the defoamer manufacturer. The long-term effectiveness of the defoamer should be considered. Some defoamers are good at first, and the effect is much worse after a period of time.