The pretreatment of the workpiece, the covering of the uncoated part of the surface, the thermal curing after spraying, the surface cleaning after the workpiece is cooled, and the repair of the defect in the coating method of electrostatic spraying powder are the same as the fluidized bed coating method. . Here we will only introduce the spraying construction and quality requirements .
The equipment used for electrostatic spraying is high-voltage electrostatic generator, powder Spray Gun, powder supply device, recovery device and empty machine, etc. When spraying, the workpiece should be grounded, and the Spray Gun should be connected to the negative height and long power supply. The Spray Gun can be single Spray Gun or multiple Spray Guns. The single Spray Gun should be portable, and the multiple Spray Guns should be fixed or turntable automatic spraying. Technical parameters during spraying: output voltage 40~100kV ; powder feeding pressure 0.05-0.2MPa; spraying distance 200-300mm; powder conveying volume 70~ 200g/min ; conveying speed about 1m/ min ; Humidity 60%~ 80%. Immediately after spraying, check whether the coating has quality defects If found, it should be repaired in time to pass. The coating inspection and quality indicators of electrostatic spraying are shown in Table 4-55.
| project | Testing method | Quality Index |
| Coating Appearance | visual inspection | Flat and smooth, uniform thickness, no impurities and spray leakage, slight orange peel is allowed |
| Paint color | Compare with standard swatches | Comply with standard swatch colors or colors requested by users |
| luster | Visual or photoelectric light meter | According to the gloss required by the user, such as glossy, semi-glossy or dull, it is tested according to the standard |
| Corner coverage | visual inspection | The corners should be tightly covered, and there should be no exposed bottom, thin paint film or spray leakage |
| Defects such as pinholes, pockmarks, and shrinkage cavities | visual inspection | The coating is smooth and flat, with good leveling and no defects such as pinholes, pitting, and shrinkage cavities. |
