Based on the characteristics of wrought iron doors, a combination of automatic and manual spray touch-up is adopted to ensure real-time monitoring of the spray coating quality and maintain product stability. The curing conditions for general polyester powder coatings are typically 200°C for 10 minutes, achieved by adjusting the furnace temperature and chain speed to guarantee the curing temperature and duration.
Iron gates should be dried with cold air after painting, and during the drying process, the workpieces should be inspected. For permissible defects such as dripping, bubbling, exposed substrate, and pinholes in the thinned powder coating, apply or spray the coating on the defect surface while the workpiece is still wet, allowing the residual heat to cure. For major defects, repair treatment is required. Different methods are chosen based on the film thickness, typically including direct respraying, mechanical polishing, and treatment with a stripping agent.
