Inclusion range of coating pretreatment

Pre coating treatment includes three parts: degreasing, derusting and phosphating. Is the central link of phosphating, degreasing and derusting is the preparation procedure before phosphating so in the production practice of electrophoretic coating production line, not only should the phosphating working as a key, but also from the phosphating quality requirements, grasp the degreasing and derusting work, with particular attention to the mutual influence between them.

Degreasing and derusting

High quality phosphating film is formed only on the surface of the workpiece which completely removes the foreign matter such as oil, rust, oxide and so on. Because the residual oil, rust, oxidation skin on the surface of the workpiece will seriously hinder the growth of phosphating film. In addition, the adhesion, drying properties, decorative properties and corrosion resistance of the coating will be affected. The removal of these foreign bodies is a necessary condition for phosphating.

Remove oil and rust are two basic processes, before phosphating relatively oil than rust caused great harm, but also directly affect the workpiece oil rust speed, therefore, should be based on the rust removing oil, but much less oil for the rust can also be in addition to the two basic processes of oil and derusting be made one in a groove, and rust removal process, can shorten the electrophoretic coating production line equipment and plant, reduce investment costs, but the quality is not as good as the treatment tank, less demanding on the occasion can be used. After using this process, degreasing agent should also choose acidic Yao agent and rust remover matching use. Rust removal using hydrochloric acid, hydrochloric acid cleaning speed, rust and clean thoroughly, the oxide skin also has good removal function, and is used at room temperature, drawback is large rust hydrochloride acid mist, harmful to health, environmental pollution is serious.

With the development of industry, the improvement of environmental protection and labor conditions has become a common concern. Therefore, environmental protection should be taken into consideration when selecting chemicals. So the choice of degreasing agent requires simple preparation, strong decontamination ability, not including room temperature difficult to clean sodium hydroxide, silicate, OP emulsifier and other ingredients, under normal temperature, easy to wash, do not contain toxic substances, no harmful gas, good working conditions; the choice of accelerator requirements contains rust agent, corrosion inhibitor and inhibitor, can to improve the speed of rust, preventing corrosion and hydrogen embrittlement of workpiece, capable of inhibiting acid fog. Of particular importance is the inhibition of acid fog, mist generated in the process of pickling rust, not only the corrosion of equipment and plant, environmental pollution, and corrosion can cause teeth, teeth conjunctival redness, tears, pain, dry throat, cough and other symptoms, so inhibit the acid mist, not only environmental protection needs, or the needs of the units themselves the.

The consideration of the above request, after screening, degreasing and derusting agent we use the company's XH-16C in preparation of Xianghe phosphatizing oil and rust additives and checking, use at room temperature, processing time is 10-30min, it can increase the speed of rust, preventing corrosion and hydrogen embrittlement of workpiece, capable of inhibiting acid fog.