Common problems and solutions in electrostatic spraying process

       There are often some problems in electrostatic spraying, how to solve these common little things quickly and effectively? Chongqing Plastic Spray Factory summarizes several problems and solutions: Pinhole The main reason...

There are often some problems in electrostatic spraying, how to solve these common little things quickly and effectively? Chongqing Spray Plastic Factory summarizes several problems and solutions:



 



pinhole



 



The main reasons are: ①The workpiece panel is corroded; ②The galvanized substrate contains hydrogen ions; ③It turns yellow after pre-phosphating; The exchange resin desalinated water is acidic; ⑥Powder quality.



 



Shrinkage



 



Main reasons: ① Water or oil enters the powder production process. The shrinkage cavities are evenly distributed, in the form of small round pits or large pinholes; 2. Other powders are mixed in during the spraying process, resulting in shrinkage cavities due to incompatibility; 3. External interference substances contaminate the spraying system including workpieces, especially if there is silicon-containing mold release in the workshop ④ There are large and deep holes on the surface of the casting; ⑤ There are round pits in the coating, and they are large, commonly known as "fish eyes"; ⑥ The compressed air oil content is high.



Solutions: ①Contact the manufacturer to change the powder; ②The powder room must be the cleanest when changing the powder, first sort out the cleaning and inspection procedures; ③Carefully inspect the powder spraying site to eliminate these interfering substances, and strictly prevent the introduction of these interfering substances; ④Sand blasting, castings can be preheated. The preheating temperature and time depend on the material and thickness; Filter, install oil-water separator, and discharge regularly every shift.