Pretreatment( immersion and spray type two kinds )
in order to remove oil, dirt, rust on the surface of the workpiece, and generate a anticorrosive phosphate layer on workpiece surface which could increase the spraying coating adhesion.
1) IMMERSION TYPE PRETREATMENT
2)SPRAY STYPE PRETREATMENT
There are about three kinds of powder coating line, manual, manual- automatic, automatic. in the manual powde coating line and manual-automatic spray line, the workpeice should be pretreated by humansource, in automatic powder coating line, the pretreatment also could be complete on the line. This according to the size of the workplace and the output.