The meaning of self -swimming coatings and coating process

Self -painted paint is also known as automatic sedimentary coatings. In the 1970s, it was invented by ACHEM in the United States and was applied to industrial coating in the mid -70s. Because it belongs to water -based coatings, the coating method is similar to the electrophoretic paint, but the different electricity is different, but different electricity Chemistry can cover the surface of the iron to form coatings. The steel surface can be painted after removing rust, and there is no need to phosphrate. In the 1980s, the United States, Canada, France, Japan and other countries had been used in car parts in automobile parts, and in the mid -1980s, my country had used self -swimming paint for car body and cargo box paint. The international advanced level is not large.

1. Basic principles

The self -swimming coatings are generally prepared by the water -based decentralized liquid and water -based carbon black pulp of organic polymer. At the time of deposition, the automatic deposition chemical reaction material is added to the slot, such as Fef3, HF, H2O2, etc. When painting, immerse the coating workpiece in the paint slot, and the surface of HF and Fef3 corrodes workpieces. Some of the dissolved FE and resin reactions, resin and pigments are folded on the surface of metal workpieces The oxidation oxidation in the trough solution forms FEF3 stable slot solution.

The chemical reaction type is as follows:

Solubility reaction: Fe (workpiece)+2HF → Fe2 ++ H2+2F-Fe (workpiece)+2FEF3 → 3Fe2 ++ 6F-

Oxidation reaction after film formation

FE2 ++ resin → Fe-resin

2FE2 ++ H2O2+2HF → 2Fe3+2H2O+2F-21FE3+6F- → 2Fef3

The main process process of painting

Workpiece skipping → water washing → pure water flushing → self -swimming painting → water washing → post -treatment → baking

If the workpiece needs to remove rust, it needs to be scrubbed and rinsed with tap water, and the rust removal treatment is performed. Then wash it with tap water and add a neutralized process. Finally, rinse it and then swim to paint. Self-swimming time, slot coating parameters, paint temperature, etc., the main process parameters, different controls according to different film compositions. Generally speaking, the deposition time is generally 1-6min, the concentration of the groove is 5-15%, and the curing temperature is solid. Generally between 110 ℃ -120 ℃.

2. The main features of self -swimming coatings

(1) Water as a dispersant, generally does not contain organic solvents. It is a safe and environmentally friendly coating without VOC.

(2) The coating process is stable and easy to manage.

(3) Painting method, uniform coating, no dead corner of painting.

(4) Energy saving of crafts and low cost.

(5) Good matching with the bottom paint!