Coated steel coating mass control inspection instructions

Coating quality control of prepainted board

The quality control of the color-coated plate coating is usually carried out in three stages. That is, the control before coating, the process of coating construction and the control after coating according to the degree of failure of the coating. The control before coating and during coating construction is very important and can be said to play a decisive role. The quality control after topcoating is actually a feedback to the first two stages, and it is a means to search for the cause of quality defects. Therefore, the operator must strictly follow the process regulations and operating procedures during the entire coating construction process.

Pre-coating control inspection link

(1) Check whether the steel strip has been tested and analyzed for surface defects and plate shape before surface treatment.

(2) Check the degreasing and cleaning effect on the surface of the steel strip,

(3) Check whether the thickness of the chemical liquid film on the surface of the steel strip is in accordance with the national industry standards.

(4) Check whether the surface of the steel strip meets the requirements of the surface temperature and humidity of the coated substrate. (Related instrument: temperature and humidity meter)

(5) The type, specification, and viscosity of the coating and thinner before being used on the machine (relevant instrument: viscometer) .

(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 (relevant instrument: wet Film Thickness Gauge) .

(2) Whether there is missing phenomenon such as leakage or discontinuity in the wet film.

(3) Whether the speed ratio between the last roller and the production line meets the process requirements

(4) The drying temperature of each section of the curing furnace.

Post-coating control checks

(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 to the substrate and the adhesion between coating and spreading.

(4) Check other properties of the coating according to the quality standards of the coating.