Cleaning materials

There are several types of cleaning materials: petroleum solvents, halogenated hydrocarbon solvents, alkaline chemical aqueous solutions, emulsions, etc. Simply put, there are two types of solvent cleaning and lye cleaning.

1) Common organic solvents are:

Petroleum solvents include solvent gasoline, kerosene, n-hexane, etc.; aromatic solvents include toluene, xylene, etc.; chlorinated solvents include trichloroethane, trichloroethylene, tetrachloroethylene, methylene chloride, etc.

Organic solvents are characterized by high degreasing efficiency, especially for removing grease with high viscosity and high dripping points. They can also be cleaned manually at room temperature with simple utensils and petroleum-based solvents. Parts of various sizes and shapes are suitable, one is still used in factories with low output, low level of mechanization and special requirements.

In order to clean the oil stains, use organic solvents at least twice. After a period of use, when the oil stains in the solvent increase to a certain level, replace them in time, and then use a relatively clean solvent for one cleaning.

In addition to liquid phase organic solvent degreasing, there is also gas phase organic solvent degreasing. For example, using trichloroethylene, trichloromethane and other substances, their boiling point is low, they are easy to vaporize when heated, they are easy to liquefy when cold, the vapor density is high, the vapor interface is not easy to diffuse, does not burn, and has strong solubility (the dissolution of trichloroethylene at 15 degrees) The capacity is four times greater than gasoline, and seven times greater at 50 degrees), so it is commonly used for gas phase degreasing, that is, the parts are placed in the vapor of such organic solvents and the vapor is condensed on the cold parts, and the grease on the parts is dissolved in the The liquefied organic solvent is separated from the part, and the liquefied solvent is heated to vapor. This process continues until the temperature of the surface of the part equals the temperature of the solvent, and the vapor is no longer liquefied.

Although Qixiang organic solvents have high degreasing efficiency, they cannot wash away inorganic salts and alkalis, and cannot remove dust particles on parts. The combination of trichloroethylene immersion washing, gas phase washing and spray washing can obtain an excellent cleaning effect. Due to the poor working conditions and high toxicity of using organic solvents for degreasing, gas-phase degreasing must have good enclosed degreasing equipment and general equipment. Most organic solvents have strict fire protection requirements and high degreasing costs. Now there are highly efficient water for betting on the host. With the emergence of base cleaning agents, organic solvents are generally no longer used to remove oil.