News 
News 
News -
Contact Us
-
Phone number：+1-312-443-3605
Fax：
E-Mail：root@osirsmybou.com
Addresses：The Art Institute of Chicago, 111 S Michigan Ave, Chicago, IL 60606
How to avoid paint peeling in sheet metal coating process
Category：answer Publishing time：2025-12-22 05:58:53 Browse： Times
In modern industrial manufacturing, sheet metal spraying technology is widely used in many fields such as automobiles, machinery and equipment, and building decoration. Good spraying quality can not only enhance the aesthetic appeal of the product but also improve its corrosion and oxidation resistance. However, in the actual operation process, paint peeling often occurs, seriously affecting the service life and aesthetics of the product. Therefore, how to avoid paint peeling in the process of sheet metal spraying is an important topic that every technical personnel engaged in spraying must master.
1. Choose appropriate spraying materials
The quality and compatibility of the spraying material are one of the key factors affecting the adhesion of the coating. Firstly, the selection of primer, topcoat, and thinner should be matched, to avoid paint peeling caused by material incompatibility. Secondly, the spraying material should be selected according to the sheet metal material (such as cold-rolled steel plate, galvanized plate, stainless steel, etc.) to choose a suitable primer to enhance adhesion. For example, galvanized sheet should be selected with special phosphatizing primer to enhance the bonding force between the coating and the base material.
2. Strictly control the surface pretreatment process
Surface treatment before spraying is the foundation for determining the quality of the coating. Paint peeling problems often originate from insufficient cleanliness of the base material surface, incomplete removal of oil污, or unremoved oxidation layers. Therefore, thorough degreasing, dust removal, and rust removal treatments should be carried out before spraying. Common treatment methods include:
- Degreasing treatment: alkaline cleaners or solvents are used to remove oil on the metal surface;
- Grinding treatment: sandpaper or sandblasting process is used to remove surface burrs, old paint layers, and oxidation skin;
- Phosphatization treatment: a phosphatizing film is formed on the metal surface to improve the adhesion of the primer.
Only the sheet metal surface that has been standardized pre-treated can ensure the good adhesion of the coating, thereby effectively avoiding paint peeling.
3. Optimize the spraying construction process
The control of spraying parameters during the spraying process also directly affects the coating quality. It mainly includes:
- Spraying thickness control: too thick coatings are prone to internal stress, causing cracking and falling off; the principle of 'thin multi-coats' should be followed;
- Environmental temperature and humidity control: the construction environment should be well-ventilated, the temperature should generally be controlled between 15-30℃, and the relative humidity should be below 80%;
- Spraying distance and angle: the gun distance should be controlled between 20-30 centimeters, the spray gun should be kept perpendicular to the workpiece to ensure uniform coating.
In addition, the drying time between the primer and the topcoat should be sufficient, and it should not be rushed to cover it, otherwise it will affect the interlayer adhesion.
4. Strengthen curing and post-treatment
After coating, the coating must undergo a sufficient drying or baking curing process. For coatings that require high-temperature curing, the temperature and time should be strictly set according to the product manual; coatings that are naturally dried should also be placed in a dry environment to avoid premature contact with moisture or external impact.
Conclusion
In summary, to avoid the problem of paint peeling in sheet metal coating, strict control is required in all aspects from material selection, surface treatment, coating process to post-curing. Neglect in any link can lead to the failure of the entire coating system. Only by establishing a scientific and standardized coating process and strictly implementing operational standards can the coating quality be effectively improved, the service life of the product be extended, and the increasingly high requirements of industrial manufacturing be met.
In modern industrial manufacturing, sheet metal spraying technology is widely used in many fields such as automobiles, machinery and equipment, and building decoration. Good spraying quality can not only enhance the aesthetic appeal of the product but also improve its corrosion and oxidation resistance. However, in the actual operation process, paint peeling often occurs, seriously affecting the service life and aesthetics of the product. Therefore, how to avoid paint peeling in the process of sheet metal spraying is an important topic that every technical personnel engaged in spraying must master.
1. Choose appropriate spraying materials
The quality and compatibility of the spraying material are one of the key factors affecting the adhesion of the coating. Firstly, the selection of primer, topcoat, and thinner should be matched, to avoid paint peeling caused by material incompatibility. Secondly, the spraying material should be selected according to the sheet metal material (such as cold-rolled steel plate, galvanized plate, stainless steel, etc.) to choose a suitable primer to enhance adhesion. For example, galvanized sheet should be selected with special phosphatizing primer to enhance the bonding force between the coating and the base material.
2. Strictly control the surface pretreatment process
Surface treatment before spraying is the foundation for determining the quality of the coating. Paint peeling problems often originate from insufficient cleanliness of the base material surface, incomplete removal of oil污, or unremoved oxidation layers. Therefore, thorough degreasing, dust removal, and rust removal treatments should be carried out before spraying. Common treatment methods include:
- Degreasing treatment: alkaline cleaners or solvents are used to remove oil on the metal surface;
- Grinding treatment: sandpaper or sandblasting process is used to remove surface burrs, old paint layers, and oxidation skin;
- Phosphatization treatment: a phosphatizing film is formed on the metal surface to improve the adhesion of the primer.
Only the sheet metal surface that has been standardized pre-treated can ensure the good adhesion of the coating, thereby effectively avoiding paint peeling.
3. Optimize the spraying construction process
The control of spraying parameters during the spraying process also directly affects the coating quality. It mainly includes:
- Spraying thickness control: too thick coatings are prone to internal stress, causing cracking and falling off; the principle of 'thin multi-coats' should be followed;
- Environmental temperature and humidity control: the construction environment should be well-ventilated, the temperature should generally be controlled between 15-30℃, and the relative humidity should be below 80%;
- Spraying distance and angle: the gun distance should be controlled between 20-30 centimeters, the spray gun should be kept perpendicular to the workpiece to ensure uniform coating.
In addition, the drying time between the primer and the topcoat should be sufficient, and it should not be rushed to cover it, otherwise it will affect the interlayer adhesion.
4. Strengthen curing and post-treatment
After coating, the coating must undergo a sufficient drying or baking curing process. For coatings that require high-temperature curing, the temperature and time should be strictly set according to the product manual; coatings that are naturally dried should also be placed in a dry environment to avoid premature contact with moisture or external impact.
Conclusion
In summary, to avoid the problem of paint peeling in sheet metal coating, strict control is required in all aspects from material selection, surface treatment, coating process to post-curing. Neglect in any link can lead to the failure of the entire coating system. Only by establishing a scientific and standardized coating process and strictly implementing operational standards can the coating quality be effectively improved, the service life of the product be extended, and the increasingly high requirements of industrial manufacturing be met.
