Engineering machinery parts need to be cleaned before assembly, during assembly, and after assembly. Some parts are also cleaned after trial operation as needed. So how to properly clean the mechanical parts? Let's take a look at the next
The purpose of cleaning the parts is to remove all kinds of dirt such as foundry sand, iron filings, rust, abrasives, oil stains, dust and the like remaining on the surface. The cleanliness of the parts after cleaning will directly affect the assembly quality and the service life of the construction machinery. Therefore, the cleaning of the parts is an important part of the engineering machinery assembly. For the cleaning of parts, the cleaning agent and cleaning method should be properly selected according to the material, structural characteristics, pollution and cleanliness requirements.
The oil stains of construction machinery parts are mainly formed by unsaponifiable oil and dust, impurities and the like. Unsaponifiable oils do not work with strong bases. For example, various mineral oils and lubricating oils are insoluble in water but soluble in organic solvents. There are two methods of removing such oils: chemical and electrochemical; commonly used cleaning solutions are organic solvents, alkaline solutions and chemical cleaning solutions; cleaning methods include manual cleaning and mechanical cleaning.
1. Three kinds of cleaning liquid
(1) Organic solvent. Commonly found are kerosene, light diesel, gasoline, acetone, alcohol and trichloroethylene. By removing oil by this dissolution method, various fats and oils can be dissolved. The advantage is that it does not need heating, is easy to use, has no damage to metal, and has good cleaning effect. The disadvantages are that most of them are flammable, high cost, suitable for precision parts and parts that are not suitable for cleaning with hot alkaline solution, such as plastic, nylon, cowhide, felt parts and so on. However, it should be noted that the rubber parts cannot be cleaned with an organic solvent.
(2) Alkaline solution. The alkaline solution is an aqueous solution of an alkali or an alkaline salt, which uses an emulsifier to remove oil from the emulsification of the unsaponifiable oil, and is the most widely used decontamination cleaning solution.
(3) Emulsification is a liquid in which very fine particles are formed and uniformly distributed in another liquid. Adding an emulsifier to the alkali solution to form an emulsion can reduce the surface tension and adhesion of the oil film, and after the oil film is broken into extremely small oil droplets, it does not return to the metal surface to remove the oil stain. Commonly used emulsifiers are soap, water glass (sodium silicate), bone glue, gum, triethanolamine, synthetic detergent and the like. It should be noted that parts with different materials should be cleaned with different cleaning solutions. Alkaline solutions have different degrees of corrosion to metals, especially to aluminum.