The oil pollution of construction machinery parts such as small road rollers is mainly formed by unsaponifiable oil, dirt, impurities, etc. Unsaponifiable oils cannot be used with strong bases, for example, various mineral oils and lubricants are insoluble in water but soluble in organic solvents. There are two methods of removing these oils: chemical and electrochemical methods. Commonly used cleaning solutions are organic solvents, alkaline solutions and chemical cleaning solutions; cleaning methods include manual cleaning and mechanical cleaning.
The first is the organic solvent. Usually kerosene, light diesel oil, gasoline, acetone, alcohol and trichloroethylene. By removing oil by this dissolving method, various oils and fats can be dissolved. The advantages are that no heating is required, it is easy to use, it does not damage the metal, and the cleaning effect is excellent. The disadvantage is that they are mostly flammable, expensive and suitable for precision parts and parts that are not suitable for cleaning with hot alkaline solutions, such as plastic, nylon, cowhide, felt parts, etc. However, rubber parts cannot be cleaned with organic solvents.
Secondly, it is an alkaline solution. Alkaline solutions are aqueous solutions of alkali metal salts or alkali metal salts that use emulsifiers to remove oils from emulsification of non-saponified oils, and are the most widely used decontamination cleaning fluids.
Emulsification is a process in which a liquid is formed into very small fine particles and distributed evenly in other liquids. Adding an emulsifier to an alkaline solution to form an emulsion reduces the surface tension and adhesion of the oil film, and after the oil film breaks into very small oil droplets, it does not return to the metal surface to remove oily stains. Commonly used emulsifiers are soap, water glass (sodium silicate), bone glue, chewing gum, triethanolamine, synthetic detergents, etc. Parts with different materials should be cleaned with different cleaning solutions. Alkaline solutions corrode metals, especially aluminum, to varying degrees. When washing with alkaline solutions, it is usually necessary to heat the solution to 80-90°C. After degreasing, rinse with hot water and remove residual liquid from the surface to prevent corrosion of parts.
Chemical cleaning fluid. It is an aqueous solution of chemically synthesized water-based metal cleaners, mainly composed of surfactants, with strong decontamination capabilities. In addition, the cleaner also contains some adjuvants that can improve or enhance the overall performance of metal cleaners, such as corrosion protection, rust prevention and carbon deposition.
