The control of the coating quality of color-coated boards is usually carried out in three stages. That is, pre-coating control, coating construction process and post -coating control are based on the failure degree of the coating. Among them, the control before coating and during the coating construction process is very important, which can be said to play a decisive role, while the quality control after coating is actually a feedback to the first two stages, which is a cause of quality defects. Find means. Therefore, the operator must strictly follow the process regulations and operating procedures .
The pre-coating control mainly includes the following inspection links:
(1) Check whether the steel strip surface has been tested and analyzed for surface defects and plate shape before surface treatment.
(2) Check the degreasing and cleaning effect of the steel strip surface.
(3) Check whether the thickness of the chemical liquid film on the surface of the steel strip is in accordance with the national or industry standards.
(4) Check whether the surface of the steel strip meets the requirements of the surface temperature and humidity of the coated substrate.
(5) The type, specification and viscosity of the paint and thinner before being put on the machine.
(6) The ambient temperature of the coating room.
The coating construction process control mainly includes the following inspection links:
(1) Wet film thickness of primer and topcoat paint.
(2) Whether there is missing phenomenon such as leakage or discontinuity in the wet film.
(3) Whether the speed ratio between the rollers on the coating head and the production line meets the process requirements.
(4) The drying temperature of each section of the curing furnace.
The control after coating mainly includes the following inspection links:
(1): Check the surface state of the coating, including whether there are surface defects, gloss and color, etc.
(2) Check whether the total thickness of the dry film meets the design requirements according to national or industry standards.
(3) Check the adhesion of the coating to the substrate and the adhesion between the coatings.
(4) Check other properties of the coating according to the quality standards of the coating.
