According to the standard, when the metal products are packed, they should first be pre-treated, that is, cleaned and dried. The purpose is to ensure a certain degree of cleanliness between the metals. Bearing system precision basic parts, its product cleanliness has a greater impact on its performance and life, cleanliness is low noise, high reliability, long life, precision bearing important quality indicators. Major bearing companies abroad have corresponding control indicators for bearing cleanliness, and China also has similar cleanliness standards. In order to make the metal parts reach the cleanliness required by people, cleaning materials, cleaning processes and equipment are the key.

Cleaning media can be roughly divided into organic solvents and water-based. Organic solvent cleaning class, if according to the cleaning process, can be divided into solvent cleaning class, gas phase cleaning class; According to the flammability of the solvent, it can be divided into combustible solvent and non-combustible solvent; In the gas phase cleaning class, it can be divided into the ozone layer destruction class and the replacement ODS class. Water-based cleaning media include acidic solvents, alkaline cleaning agents, water-based cleaning agents containing surfactants, etc. Water-based cleaning agents containing surfactants also include a simple surfactant and a surfactant and organic solvent compound. The latter also has emulsifying, microemulsifying type. Among them, the microemulsified stock solution is the semi-water-based cleaning medium.

After the metal products and parts are cleaned, the surface of the cleaned bearing parts is still accompanied by a part of the medium liquid, so the medium liquid needs to be removed by gasification method, which is called the drying process.

The requirements of the drying process for cleaning media are as follows:

1, low boiling point, small gasification heat, small specific heat capacity, easy to volatilize removal;

2, low surface tension, easy to spread on the surface of the object, so easy to evaporate;

3. High flash point and ignition point, non-flammable and explosive, good safety;

4, the medium liquid is less toxic, less harmful to workers' health, and has a damaging effect on the environment.