Application of surfactants

Metal processing includes metal cleaning, surface coating and metal turning, milling, planing, cobalt, rolling, casting and other processing processes. In order to reduce labor intensity, improve product quality, save energy and reduce costs, some auxiliaries are often used in various processing processes, among which surfactants play a very important role. A surfactant is a substance that can significantly reduce the surface tension or interfacial tension of a liquid. Their molecules are composed of two parts: a polar hydrophilic group and a non-polar hydrophobic/oleophilic group. Because they have both hydrophilic and oil-philic properties, the surface properties of the cleaning solution can be changed during chemical cleaning so that it has a lower surface tension.

Surfactants can be divided into anionic, cationic, nonionic and amphoteric types according to the charge of the surface active part. Surfactants have the properties of wetting, foaming, solubilizing and defoaming. Metal cleaning actually runs through the entire metal processing process. The cleaning agent is mainly composed of three components: main cleaning agent, corrosion inhibitor and surfactant. Surfactants play a role in the cleaning of adsorption, penetration, emulsification, dissolution, washing, etc., because the surface is not only used as an auxiliary agent in chemical cleaning, but also as the main component and has been widely paid attention to, especially in pickling, alkali washing, corrosion inhibition, oil removal and other cleaning process has played an increasing role. The surfactants commonly used in metal processing and cleaning are fatty alcohol polyoxyethylene ether, alkyl phenol polyoxyethylene ether, sodium dodecyl benzene sulfonate, dodecyl glycol amide, sodium methoxyfatty amide benzene sulfonate, etc.