The control of the coating quality of color-coated boards is usually divided into three stages, including pre-coating control, highlighting the construction process, and post-coating control according to 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 belongs to the search for the cause of quality defects. means. Therefore, the operator must strictly follow the process procedures and operating procedures during the entire coating construction process.
(1) Check whether the steel 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 surface.
(3) Check whether the thickness of the chemical liquid film on the steel surface is in accordance with national or industry standards.
(4) Check whether the steel surface meets the requirements of the coated substrate in terms of surface temperature and humidity.
(5) The type, price and viscosity of the paint and thinner before being put on the machine.
(6) The ambient temperature of the coating room.
(1) The wet film thickness of the primer and topcoat.
(2) Whether there is missing phenomenon such as leakage or discontinuity of wet film.
(3) Whether the speed ratio between the upper roller of the coating head and the production line meets the process requirements.
(4) The drying temperature of each section of the curing furnace.
(1) Check the surface condition 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 or the substrate and the adhesion between the coatings.
(4) Check other properties of the coating according to the quality standards of the coating.