In the metal processing industry, metalworking fluids such as cutting fluid, emulsified oil, polishing fluid, etc. are indispensable auxiliary materials. Under the action of high temperature and high shear force, these processing fluids are easy to produce a large number of stable foam because they contain a large number of surfactants. The existence of foam will not only affect the lubrication, cooling and rust prevention properties of processing fluid, but also affect the cleanness and appearance of metal, thus seriously affecting the quality of metal products. Therefore, the use of defoamers in the metal processing industry has become crucial.

Metal processing fluid defoamers mainly destroy the stability of bubbles by reducing the surface tension of the liquid, allowing bubbles to be quickly eliminated. Common types of defoamers include surfactants, organosilicon defoamers, inorganic defoamers, and composite defoamers.

Surfactant based defoamers have good dispersibility and stability, and can quickly reduce the number of bubbles in metalworking fluids. Organosilicon defoamers form a thin film covering the surface of bubbles to prevent their regeneration, with minimal impact on metalworking fluids and no adverse effects on metal materials. Inorganic defoamers disrupt the stability of bubbles by altering factors such as ion concentration and pH value in metalworking fluids. However, their composition is complex and should be used in conjunction with other components. Composite defoamers are composed of multiple defoamers, which can achieve the best defoaming effect under different conditions and usually have good stability and durability.

Defoamers for metalworking fluids are widely used, not only for cutting fluids, micro lotion, hydraulic oils with high water content, but also for solvent cleaning, acid-base water-based cleaning agents, coolants, grinding fluids and other metalworking fluids. The use of defoamer can effectively control the foam phenomenon during metal processing, ensure the stability of processing fluid and processing effect, and thus improve the quality of metal products.