The hardness of electrophoretic coating is an important parameter that affects the quality of electrophoretic coating film. It mainly refers to the ability of the material to resist the pressure or friction of hard objects on its surface. However, in the production process of electrophoretic coating, due to various reasons, the electrophoretic coating film sometimes has insufficient hardness. If the hardness of the electrophoretic paint film decreases, it will cause the paint film to fall off, scratch, and even lead to the return of the whole batch. So how can we effectively improve the hardness of the paint film? Methods to improve the hardness of electrophoretic paint film:
1. The surface of the coated workpiece is flat and free of burrs.
2. The pretreatment shall be done well to ensure that the surface is clean and free of oil stain.
3. The electrophoretic paint should be stable, uniform, delicate and homogeneous.
4. Properly increase the thickness of electrophoretic paint film to improve the hardness of electrophoretic paint film. The paint film is thin, and it is easy to scratch the paint film and expose the bottom when scraping and touching each other; However, the thick paint film will not expose the bottom even if it is scratched, and still has a protective effect on the electrophoretic workpiece.
5. Strengthen the management of hanging, packaging and transportation process to avoid the collision between finished electrophoresis products. No matter how hard the electrophoretic paint film is, the collision of the workpiece will inevitably lead to the paint film injury, which is easy to cause the misunderstanding that the paint film hardness is not enough.
6. The baking shall be sufficient. The baking temperature and time shall be in accordance with the process requirements. The baking shall be sufficient and the temperature shall be guaranteed to ensure the complete curing of the coating film. Some electrophoretic coating plants use the same baking conditions to bake large and small pieces and different thickness pieces together, which will cause discoloration of thin pieces during high-temperature baking and drying of thick pieces, resulting in different drying degree of paint film and affecting the hardness and performance of electrophoretic paint film.
