In modern industrial production, foam is everywhere. Bubbles, causing problems in industrial production. In order to prevent foam overflow, the feeding coefficient is forced to reduce 30% to 50%; Foam overflow leads to waste of raw materials; Foam occupies space, affects the reaction speed, and the production cycle is forced to extend.










Foam will affect product quality, for the foam problem, the most direct solution is to use defoamer.






A defoamer is an additive whose function is to eliminate the foam formed by the material during the production process. Silicone defoamer its main component is called silicone oil silicone composition, silicone oil at room temperature is a non-volatile oily liquid, insoluble in water, animal and plant oil and mineral oil, or solubility is very small, both high temperature and low temperature resistance. Chemical properties are inert, physical properties are stable, no biological activity.






















Mechanism of organosilicon defoamer






Silicone defoamer eliminates foam mainly through the action of surface tension. When the silicone defoamer is added, the silicone compound is dissolved in water to form an aqueous solution, in which a layer of hydrophobic surfactant solution is formed.






Due to the hydrophilic and lipophilic properties of hydrophobic surfactant molecules, the surfactant solution has a strong interfacial tension to a certain extent, which prevents the surface tension of the foam solution. In addition, due to the strong adsorption of hydrophobic surfactant molecules to water, hydrogen bonds are formed between water molecules and hydrophobic groups, thereby preventing the surface tension of the foam solution.










The advantages of silicone defoamer






01 Wide range of applications


Due to the special chemical structure of silicone oil, it is neither soluble with water or substances containing polar groups, nor is it soluble with hydrocarbons or organic compounds containing hydrocarbon groups. Because of the insolubility of silicone oil to various substances, it is widely used, which can be used for water system defoaming and oil system.


02 Low surface tension


The surface capacity of silicone oil is generally 20-21 dynes/cm, which is smaller than the surface tension of water (72 dynes/cm) and general foaming liquid, and the antifoam effect is good.


03 Good thermal stability


Taking the commonly used dimethyl silicone oil as an example, it can withstand 150 ° C for a long time, and can withstand more than 300 ° C for a short time, and its Si-O bond does not decompose. This ensures that the silicone defoamer can be used over a wide temperature range.


04 Good chemical stability


Because the Si-O bond is relatively stable, the chemical stability of silicone oil is very high, and it is difficult to chemically react with other substances. Therefore, as long as the preparation is reasonable, the silicone defoamer is allowed to be used in the system containing acid, alkali and salt.


05 Physiological inertia


Silicone oil has been shown to be non-toxic to humans and animals at semi-lethal doses greater than 34 g/kg. Therefore, silicone defoamer (in the combination of suitable non-toxic emulsifiers, etc.) can be safely used in food, medical, pharmaceutical and cosmetics industries.


06 Strong defoaming power


Silicone defoamer can not only effectively break the foam that has been formed, but also significantly inhibit the foam and prevent the formation of the foam. Its use is very small, as long as the weight of the foaming medium is added one millionth (1ppm), that can produce defoaming effect. Its common range is 1 to 100 PPM. Not only the cost is low, but also does not pollute the defoaming material.






Method of using organic silicon defoamer






Silicone defoamer has excellent anti-foam and anti-foam performance, it can be added after the foam is generated or added as a anti-foam component to the product, according to different use systems, the amount of defoamer is recommended in 10~1000ppm, the amount of addition is determined according to the specific situation.






Silicone defoamer products can be used directly or diluted. If it can be fully stirred and dispersed in the foaming system, it can be directly added without dilution. If dilution is required, follow the dilution method. The method of diluting the product directly with water is not desirable, and the phenomenon of delamination breaking is easy to occur, thus affecting the quality of the product.