From the perspective of physics, the methods to eliminate foam mainly include placing baffles or filters, mechanical stirring, static electricity, freezing, heating, steam, radiation, high-speed centrifugation, pressure and decompression, high-frequency vibration, instantaneous discharge and ultrasonic (acoustic) Liquid control), etc., these methods promote the gas permeation rate at both ends of the liquid film and the drainage of the bubble film to varying degrees, so that the stability factor of the foam is smaller than the attenuation factor, and the number of foams is gradually reduced. However, the common shortcomings of these methods are that the use is highly restricted by environmental factors, the defoaming rate is not high, etc., and the advantages are environmental protection and high recycling rate.

The application of defoamers is very wide, such as 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. .

The defoaming agent should have the following properties: ①Strong defoaming power and low dosage; ②Adding to the foaming system does not affect the basic properties of the system, that is, it does not react with the defoamed system; ③Small surface tension; ④ Surface tension Good balance; ⑤good heat resistance; ⑥good diffusibility, permeability, high positive spreading coefficient; ⑦chemical stability, strong oxidation resistance; ⑧good gas solubility and permeability; ⑨in foaming The solubility in the solution is small; ⑩ no physiological activity, high safety.