For the coating construction of strip, modern color coating machines at home and abroad basically adopt the process of two coating and two drying, that is, two coating and two drying process. The coating machine used for primer (that is, the first layer
of paint film applied on the surface of steel strip) construction is called primary coating machine.
The primary coating machine is mainly used for the coating of the primer on the front and back of the strip. At the same time, according to the requirements of the production process, the primary coating machine can also provide the primer for the printing of the strip.
Generally speaking, the thickness of the primer is relatively thin, so the primer head and the surface coating head of the primary coater are arranged in two series. In addition, the main factors affecting the surface quality of the coating are the viscosity of the coating, the proportion of diluent and the thickness of wet film. For the coating machine, the wet film thickness of the coating can be controlled by adjusting the gap pressure between the rollers of the coating head and between the coating roller and the support roller.