Cleaning Agents Used for Fasteners
Protection for performances of fasteners cannot be lack of cleaning agents. Fasteners should be usually cleaned so that performance can be made full use. The followings are the cleaning agents used for cleaning fasteners.
1. Soluble emulsion cleaner
Soluble emulsion cleaner generally consists of emulgator, soil, solvent, builder, corrosion inhibitor and water. Water is used to dissolve emulgator. The cleaner can dissolve the dirt on the surface of fasteners, meanwhile it can also form a layer of antirust film on the surface of fasteners. Emulsion cleaner is a kind of concentrated pure oil products. It becomes into white liliquoid after being diluted in water. Emulgator and detergent can hold grease particles and dissolve them into the cleaning agent containing solvent and oil.
2. Alkaline cleaner
Alkaline cleaner is mixed with builder and alkaline earth metal salts containing surfactants, also a kind of the most widely used cleaning agents. The PH of the cleaning agent should be about 7. Builder compositions of the cleaning agent are hydroxides, silicates, carbonates, phosphates, borates and organics. The every salt and surfactant are mainly used to ensure cleaning effects, economy following.
3. Decontaminant
Decontaminant mainly contains solvent, surfactant and water. It is a pure solution, not emulsion, which is different from emulsion cleaner. Decontaminant is mainly used for maintenance cleaning of equipment or external packing of fastener.
4. Synthetic detergent
Synthetic detergent is also a kind of alkaline cleaners. Chemical components of synthetic detergent are different from standard alkaline cleaner. The essence of standard alkaline cleaner is inorganic while synthetic detergent is organic agent containing amino materials. Standard alkaline cleaner is used to clean alkali residues in single cleaning. It is also a kind of better antirust agents. Synthetic detergent is used to carry out moderately difficult cleaning, such as cleaning quenching oil or quenching polymer solution on the surface of fasteners.
5. Acidic cleaner
Sulfuric acid, hydrochloric acid, nitric acid, citric acid, acetic acid and other organic acids are generally used. To eliminate phosphating film on high strength fasteners before heat treatment, the first 3 kinds of acids are mainly applied at present. Moreover, corrosion of hydrogen should be prevented. Acid agents should contain basic acid, corrosion inhibitors prevent the surface of metal fasteners from being corroded and surfactants improving cleaning ability. To clean general dirt on metal fasteners, acidic cleaner is not used, instead of alkaline cleaner. In terms of oxide skin and other special attachments, acid cleaner is effective. The most famous technique is acid leaching. Besides rolling, welding and oxide scale of heat treatment, surface oxides, rust and corrosion products having influences on the quality of electroplating or oil sealing and marine sediments can be cleaned by using acid cleaner.