Powder spraying technology of hot-melt deposition

The working principle of hot-melt deposition is to spray the powder coating on the preheated workpiece with a spray gun The powder coating is melted by the heat of the workpiece After cooling, the workpiece can be covered with the coating If necessary, it needs to be baked after treatment The key to the control of the hot deposit process is the preheating temperature of the workpiece When the preheating temperature is too high, the metal surface will be oxidized seriously, the adhesion of the coating will be reduced, and even the degradation of the powder coating and the discoloration of the coating will be caused Preheating temperature is too low The coating has poor fluidity, so it is not easy to get uniform coating The workpiece is preheated when applying four kinds of Fen final coatings, namely PVC, HDPE, Polyamide 1010 and oxidized polyether The required thickness can't be obtained by one-time spraying with hot-melt deposition method Therefore, it is necessary to spray repeatedly After each spraying, heat treatment is required to make the coating completely melt and shine, and then spray the second layer This can not only make the coating uniform and smooth, but also significantly improve the mechanical strength Heat treatment temperature of HDPE is about 170 ℃, chlorinated polyether is about 200 ℃, and time is 1 hour The coating obtained by the hot-melt deposition method has the advantages of high quality, beautiful appearance, high adhesion, small loss of powder coating, easy control and less odor The spray gun does not have a combustion system, and has a simple structure It can be used as an ordinary spray gun