The drying and curing of the powder coating line is divided into four stages: melting, leveling, gelation and curing.
There are several procedures for the powder coating line. After the temperature rises to the melting point, the surface powder on the workpiece begins to melt, and gradually forms a vortex with the internal powder until it is completely melted. After the powder is completely melted, it begins to flow slowly, forming a thin and flat layer on the surface of the workpiece. This stage is called leveling. After the temperature continues to rise to the glue point, there will be a short period of gelation for a few minutes (the temperature remains unchanged), after which the temperature continues to rise, and the powder undergoes a network glue chain reaction and completely solidifies.
Different powders are different in the baking temperature and time. Generally, the temperature of the curing oven is set at 190±10℃, and the baking time is 25±5min. The bottom of the workpiece is more than 100mm from the bottom and side walls of the oven.
Due to the high curing temperature of powder coating, the surface coating of the workpiece just out of the oven is relatively soft, which has a certain impact on the subsequent packaging process and coating performance testing. Therefore, after the exit of the workpiece oven, a certain cooling section needs to be set to cool the coating film at room temperature to ensure that the surface temperature of the coating film is close to room temperature. Only then can the quality inspector be arranged to judge the appearance quality of the workpiece coating. And it is important to choose a reliable painting line manufacturer.
If you want to obtain high-quality powder coating equipment at a reasonable price, you can seek the help of powder coating equipment manufacturer XMT. Please contact us immediately before making a decision on the powder coating project.