In the industrial production processes of petroleum, rubber, coatings, textiles, etc., if there is a large amount of foam, it will not only inconvenient the production and operation, waste equipment capacity, but also affect the quality of the product. Therefore, it is necessary to effectively control the foam during the production process. Generally, the elimination of foam can be achieved by physical methods such as high-speed centrifugation, decompression, and ultrasound. However, under the conditions of the increasing scale of industrial production and higher and higher production efficiency requirements, it is necessary to quickly and effectively eliminate the continuously generated bubbles in the shortest possible time, and new and more effective methods are needed. .
After the active ingredient formed by dimethyl silicone oil and fumed silica in the silicone defoamer is added to the foam system, the active ingredient has a lower surface activity and is quickly distributed on the liquid surface to inhibit the formation of new elastic films. That is to stop the generation of bubbles. On the other hand, the active ingredient spreads on the surface of the foam elastic film, further diffuses and penetrates the surface of the film, causing the film wall to become thinner rapidly, destroying the balance and stability of the foam. At the same time, the foam is strongly drawn by the surrounding liquid with high surface tension. This causes the bubble to break. The defoamer molecules that are insoluble in the system re-enter the surface of another foam film, and repeat this procedure, and all the foam is destroyed.
At present, there are many varieties, models and names of organic silicon defoamers at home and abroad, and their performances are different. Generally, they can be divided into oil (grease) type, solution type, emulsion type, solid type and modified silicone oil type.
Silicone defoamer not only has good defoaming and anti-foaming effects, but also has the characteristics of low dosage, good chemical inertness, and can play a role under harsh conditions. In recent years, it has developed rapidly and is suitable for different use environments. New varieties and new models Continue to produce, and the application area is also constantly expanding. In the future, new and efficient silicone defoamers with strong applicability and can further improve product quality and equipment utilization will be further developed, especially polyether modified silicone defoamers and emulsion defoamers with excellent performance. The market occupies a major position.