Coating quality control of color coated plate is a very important part in the process of color coated production. Through strict quality control, we can ensure the production of coating products that meet the requirements of the standard, improve production efficiency and product quality. The coating quality control of color coated board usually includes three stages: pre-coating control, coating construction process control and post-coating quality inspection.
Precoating control
Before coating construction, the preparation work must be strictly controlled to ensure the smooth progress of subsequent construction and the stability of coating quality.
Test and analysis before surface treatment
Před nátěrem, it is necessary to test and analyze the surface of the steel strip to check whether there are surface defects or plate shape problems and ensure the effectiveness of the surface treatment.
Degreasing cleaning effect check
Degreasing cleaning is an important step to ensure the adhesion of the coating, and it is necessary to check the cleaning effect to ensure that the surface is clean and free of contaminants.
Chemical liquid film thickness check
The chemical liquid film thickness of the coating needs to meet the national or industry standards, and checking the liquid film thickness before the coating is an important step to ensure the quality of the subsequent coating.
Surface temperature and humidity requirements
The surface temperature and humidity of the coated substrate have a direct impact on the coating quality, and it is necessary to ensure that the requirements are met to ensure the normal curing and adhesion of the coating.
Inspection of coatings and thinners
The type, specification and viscosity of coatings and thinners need to be checked to ensure that the correct material is selected and that the viscosity meets the requirements prior to construction.
Coating chamber ambient temperature control
The ambient temperature of the coating chamber has a direct influence on the fluidity and curing speed of the coating during the coating construction process, and it needs to be controlled in a suitable range.
Coating construction process control
The control during coating construction is the key to ensure uniform and stable coating construction. Here are some important controls:
Wet film thickness control
The wet film thickness of the primer and top paint needs to be strictly controlled to ensure that the thickness of the coating meets the design requirements and avoids the situation of too thick or too thin.
Missed coating and discontinuous inspection
In the process of coating construction, it is necessary to check whether there is leakage or discontinuity of wet film in time, and repair and adjust it in time.
Head speed ratio control
The speed ratio of each roller to the production line of the coating head needs to meet the process requirements to ensure uniform coating construction and avoid uneven construction.
Curing furnace temperature control
The drying temperature of each section of the curing furnace needs to be strictly controlled to ensure the normal curing and cross-linking of the coating and avoid the situation of incomplete curing.
Quality check after coating
After the completion of the coating construction, the quality inspection needs to be carried out to ensure that the quality of the coating meets the requirements of the standard, and to find and deal with possible problems in a timely manner.
Check the surface condition of the coating
Check whether there are defects on the surface of the coating, whether the gloss and color meet the requirements, and whether there is foreign matter mixed in.
Total dry film thickness check
Check whether the total thickness of the dry film of the coating meets the design requirements according to national or industry standards to ensure the protective performance and durability of the coating.
Adhesion check
Check the adhesion of the coating to the substrate and the adhesion between the coatings to ensure that the bond between the coating and the substrate is firm.
Other performance checks
According to the quality standard of the coating, check the coating’s weather resistance, chemical resistance and other important performance indicators to ensure that the comprehensive performance of the coating meets the requirements.
In summary, the coating quality control of color coated board involves many links and contents before coating, during construction and after construction. Through strict quality control, the quality and performance of coating products can be effectively improved to meet the needs of users and standards.