1。 pretreatment

1) Pretreatment process directly affects the quality of powder coating, and poor pretreatment can easily cause the coating to fall off and blister. Therefore, we must attach importance to pretreatment.

2) Chemical pretreatment can be used for sheet metal stamping parts. Namely: degreasing → derusting → cleaning → phosphating (or purification), etc. Most rusty or thick surface workpieces should be derusted by mechanical methods such as sandblasting and shot blasting, but after mechanical derusting, the surface of the workpiece should be clean and free of scale.

3) Blow putty. According to the defect degree of the workpiece, apply conductive putty, dry and smooth with sandpaper, and then proceed to the next process.

4) Protection (also called shielding). If some parts of the workpiece do not need painting, they can be covered with protective glue before preheating to avoid painting.

5) Preheating. Generally, preheating is not required. If the coating is required to be thick, the workpiece can be preheated to 100 ~ 160℃, which can increase the coating thickness.

2。 spray

The workpiece enters the spray gun position of the powder spraying room through the conveyor chain to prepare for the spraying operation. The electrostatic generator releases high-voltage static electricity (negative electrode) to the space in the direction of the workpiece through the electrode needle at the muzzle of the spray gun, so that the mixture of powder and compressed air sprayed from the nozzle of the spray gun ionizes (negatively charges) the air around the electrode. The workpiece is grounded (grounded) through the hanger and the conveying chain, so that electric field powder is formed between the spray gun and the workpiece, which reaches the surface of the workpiece under the double push of electric field force and compressed air pressure, and a uniform coating is formed on the surface of the workpiece through electrostatic attraction.

3。 Baking curing

The sprayed workpiece is sent to the drying room at 180 ~ 200℃ by the conveyor chain for heating, and the corresponding time (15-20 minutes) is kept for melting, leveling and curing, so as to obtain the required surface effect of the workpiece. Different powders have different baking temperatures and time. This should be paid attention to in the curing process.

4。 clear

After curing, remove the protector and smooth the burr.

5。 cheque

After curing, mainly check the appearance (whether it is smooth and bright, whether there are defects such as particles and shrinkage cavities) and thickness (controlled at 55 ~ 90μ m). Repair or repaint the detected defective workpieces such as missed spray, pinholes, bulges and bubbles.

6。 parcel

After passing the inspection, the finished products will be classified and placed in transport vehicles and turnover boxes, and separated from each other by soft packaging cushioning materials such as foamed paper and bubble film to prevent scratches and wear (packaging can be made according to customer requirements).