Electrostatic spraying process
Electrostatic powder spraying equipment for the powder paint spray to the workpiece surface and in the electrostatic interaction, the powder will be uniform adsorption on the surface of the workpiece, form the powder coating; powder coating by high temperature baking flow photocurable, into different final coating; spraying effect in strong mechanical degrees, adhesion, corrosion resistance, ageing resistance etc. is better than painting process.
The pretreatment process of quality has a direct impact on the quality of coating powder, before treatment is not good, resulting in the film is easy to fall off, bubble. Therefore, the work should be paid more attention to.
For sheet metal stamping with chemical pretreatment method. Namely: to oil to rust, cleaning, phosphating (or purified) etc.. Most of corrosion or surface thicker workpiece using sandblasting, Shotblast, such as mechanical method to rust, but after mechanical derusting should ensure the workpiece surface clean, unable to scale.
Putty. According to the degree of defect scraping conductive putty, drying after using sandpaper slide, you can proceed to the next step.
Protection (also known as shield cover). The workpiece is not required if certain parts can be used in coating, preheating protection glue covered to avoid spray paint.
preheat General without preheating. If the coating is thick, the workpieces can be preheated to 100 to 160 DEG C, which can increase the thickness of coating.
The workpiece by entering the dusting conveyor chain for spraying gun position. Electrostatic generator through the electrode needle gun muzzle to the direction of the workpiece space release high-voltage electrostatic (negative) and the high voltage electrostatic made from. The powder sprayed from the spray gun mouth and compressed air and the mixture of electrode ionization of the air around the (negatively charged). Workpiece after rack through transport links (grounding), thus between the spray gun and workpiece formation a field of the powder under the electric field force and the pressure of compressed air driven by dual arrived at the surface of the workpiece, by electrostatic attraction to form a uniform layer of coating on the surface of the workpiece.
The workpiece after spraying by conveying chain into 180 ~ 200 DEG C within the heating chamber, and the corresponding thermal time (15-20 minutes) to melt, leveling and curing, which workpiece surface effect we want. (different powder is different in baking temperature and time). This is should be paid attention to in the process of curing.
Remove the protective coating after curing, Hsiuping burr.
The workpiece after curing, the main daily check the appearance (whether smooth bright, no particles, shrinkage) and thickness (at 55 ~ 90 m). The workpiece is detected missing spray, pinhole, scratches, bubbles and other defects, repair or re spray.
Product classification after the check box in the car, put transportation turnover, between the foaming buffer material paper, bubble film packaging isolation, to prevent scratches wear (according to customer requirements packaging)