What pretreatment steps are required before Aluminum Plate Surface Spraying to ensure the adhesion and durability of the coating?
Publish Time: 2024-07-23
Before surface spraying, aluminum plates must undergo a series of rigorous pretreatment steps to ensure that the coating can adhere firmly and has excellent durability.
First, cleaning is a crucial step. There are often pollutants such as grease, dirt, and dust on the surface of aluminum plates. Solvent cleaning or alkaline degreasing is usually used to completely remove these impurities and create a clean surface for subsequent processing.
Next is chemical etching or pickling. The purpose of this step is to remove the oxide layer and slight scratches on the surface of the aluminum plate, while increasing the roughness of the surface. The rough surface can provide more mechanical bonding points and help the adhesion of the coating. For example, dilute hydrochloric acid or nitric acid solution can be used for pickling, but the acid concentration and treatment time need to be strictly controlled to avoid excessive corrosion.
Then comes phosphating. The phosphating solution will form a phosphating film on the surface of the aluminum plate, which can not only further improve the adhesion of the coating, but also enhance the rust resistance of the aluminum plate.
After completing the above chemical treatment, water washing and drying are required. Water washing should ensure that the residual chemical agents are completely removed, and drying should ensure that there are no water stains on the surface of the aluminum plate to prevent defects during the spraying process. In addition, in order to ensure the effect of pretreatment, the surface of the aluminum plate needs to be quality inspected. Check whether the cleanliness and roughness of the surface meet the requirements, and whether there are any residual oxide layers or impurities. Taking the spraying of automotive aluminum plate parts as an example, improper pretreatment may cause the coating to peel off, blister and other problems during use, affecting the appearance and protective performance of the car.
In short, the pretreatment before Aluminum Plate Surface Spraying is a complex and critical process. Only by strictly implementing these pretreatment steps can a strong bond between the coating and the aluminum plate surface be ensured, thereby improving the adhesion and durability of the coating, so that the aluminum plate can maintain good performance and appearance under various environmental conditions.
