Process requirements for automobile bumper coating production line: The pretreatment before the plastic automobile bumper coating production line is mainly to remove dust, oil and residual release agent on the surface of the workpiece, and at the same time, activate the surface. If the pretreatment is not good, it is easy to cause defects such as poor adhesion of the paint film, shrinkage holes and particles. There are two forms of pretreatment, one is automatic spraying and the other is manual wiping. Automatic spraying is to hang the workpiece on the conveying equipment and go through the pretreatment spraying line. The main processes are: pre-degreasing → degreasing → washing 1 → washing 2 → fresh DI washing → water blowing → moisture drying → strong cooling; manual wiping mainly It is to manually wipe the entire workpiece surface with solvent, which can reduce the one-time investment of equipment and its operating cost. Domestic large-volume plastic automobile bumper coating production lines mostly use automatic spraying, and small-volume automobile bumper coating production lines and small-piece coating mostly use manual wiping.