According to the composition, coating defoamer is divided into mineral oil, polyether, silicone, polyether modified silicone, etc.. You can choose defoamer according to the defoaming requirement of the product. If you need fast defoaming speed, silicone type defoamer is more suitable. If you want better defoaming effect, you can choose polyether defoamer. According to its performance, it can also be divided into paint defoamer with high temperature resistance, water resistance and corrosion resistance. Compared with imported products, the performance difference is not much, the price is more advantageous. Silicone defoamer has the advantages of easy dispersion, strong defoaming ability, versatility, and long foam inhibition time. It has a low dosage and a relatively wide range of applications. It can be used in water-based systems and oil-based systems. It has low surface tension, good chemical stability, and is difficult to react chemically with other substances. The powerful defoaming ability can not only effectively destroy the already formed foam, but also significantly inhibit the foam and prevent the formation of foam. It is ideal for defoaming coatings. Mineral oil defoamer has the characteristics of rapid defoaming, high efficiency, long defoaming time and good economy. It can be dispersed in water as a medium stable emulsion. It can be used under acidic and alkaline conditions. When choosing paint defoamer, please pay attention to the following properties                     1. Pay attention to the defoaming ability and stability of the defoamer. High quality coating defoamer should not only have good defoaming effect, but also should have long-lasting foam inhibition effect. 2. Whether it has the characteristics of not affecting the gloss and appearance of the coating. 3. It can be well compatible with the coating system during transportation and construction without affecting the formation of surface film, surface defects, avoiding shrinkage and fish eyes. Coating defoamer is not universal, so in different emulsion or water dispersion system, the type of coating defoamer used is also different. 4. Does the foam last during production, packaging and use? Any defoamer in the storage process will gradually fail as the environment changes and time increases. Therefore, it is important to stabilize the performance of the coating defoamer so that it does not fail quickly. A high quality coating defoamer maintains good defoaming performance and does not cause shrinkage at higher dosages. This is the only way to avoid the gradual failure of the defoamer over time after adding large amounts of defoamer in the initial stage. For general coatings, mineral oil defoamer with lower cost pe waxes can be chosen, which can reduce the cost of defoamer; for high performance coatings, it is necessary to consider whether the use of defoamer will affect the performance of the coating. In addition, the amount of such paint emulsion is large and easy to produce foam, so a high performance paint defoamer should be selected.