Fundamentals Of Powder Solidification

The epoxy group in the epoxy resin, the carboxyl group in the polyester resin and the amine group in the curing agent undergo polycondensation, addition reaction and crosslinking to form a macromolecular network, and at the same time release small molecular gas (by-product). The curing process is divided into four stages: melting, leveling, gelling and curing. After the temperature rises to the melting point, the surface powder on the workpiece begins to melt, and gradually forms a vortex with the inner powder until it is completely melted. After all the powder is 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, there is a short-term gelation state (the temperature remains unchanged) after reaching the glue point, and then the temperature continues to rise, and the powder undergoes a chemical reaction and solidifies