Quality control of color-coated board coatings is a crucial part of the color-coated production process. Through strict quality control, we can ensure the production of coating products that meet standard requirements, improving production efficiency and product quality. Quality control of color-coated plate coatings usually includes three stages: pre-coating control, coating construction process control and post-coating quality inspection.
Control before coating
Before coating construction, all preparation work must be strictly controlled to ensure the smooth progress of subsequent construction and the stability of coating quality.
Testing and analysis before surface treatment
Before coating, the surface of the steel strip needs to be tested and analyzed to check whether there are surface defects or plate shape problems to ensure the effectiveness of the surface treatment.
Degreasing cleaning effect inspection
Degreasing cleaning is an important step to ensure coating adhesion. It is necessary to check the cleaning effect to ensure that the surface is clean and free of contaminants.
Chemical film thickness inspection
The chemical liquid film thickness of the coating needs to comply with national or industry standards. Checking the liquid film thickness before coating is an important step to ensure the quality of subsequent coatings.
Surface temperature and humidity requirements
The surface temperature and humidity of the coating substrate have a direct impact on the quality of the coating, and it is necessary to ensure compliance with the requirements to ensure normal curing and adhesion of the coating.
Inspection of paint and thinner
The type, specification and viscosity of paint and thinner need to be checked to ensure that the correct materials are selected and that the viscosity meets the requirements before application.
Coating room ambient temperature control
The ambient temperature of the coating room has a direct impact on the fluidity and curing speed of the coating during the coating construction process and needs to be controlled within an appropriate range.
Coating construction process control
Control during the coating construction process is the key to ensuring uniform and stable coating application. The following are some important control aspects:
Wet film thickness control
The wet film thickness of primer and topcoat needs to be strictly controlled to ensure that the thickness of the coating meets the design requirements and avoids being too thick or too thin.
Missing coating and discontinuous inspection
During the coating construction process, it is necessary to promptly check whether there is any leakage or discontinuity in the wet film, and make timely repairs and adjustments.
Paint head speed ratio control
The speed ratio between each roller of the coating head and the production line needs to meet the process requirements to ensure uniform application of paint and avoid uneven application.
Curing oven temperature control
The drying temperature of each section of the curing oven needs to be strictly controlled to ensure normal curing and cross-linking of the coating and avoid incomplete curing.
Post-coating quality inspection
After the coating construction is completed, quality inspection is required to ensure that the coating quality meets the standard requirements, and possible problems are discovered and dealt with in a timely manner.
Coating surface condition inspection
Check whether there are defects on the coating surface, whether the gloss and color meet the requirements, and whether there is any foreign matter mixed in, etc.
Total dry film thickness inspection
Check whether the total dry film thickness 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 coatings to ensure that the bond between the coating and the substrate is firm.
Other performance checks
According to the quality standards of the coating, check the weather resistance, chemical resistance and other important performance indicators of the coating to ensure that the comprehensive performance of the coating meets the requirements.
To sum up, the quality control of color-coated board coating involves multiple 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 user needs and standard requirements.
