Surface treatment protects aluminum alloy wheels, enhances corrosion resistance to extend service life, and meets aesthetic requirements. Coating is currently the dominant process, whereas the use of electroplating is gradually declining due to environmental concerns.
Coating methods include manual and automatic spraying; manual spraying makes it difficult to control coating thickness and quality, whereas automatic spraying allows for precise and uniform control of coating thickness. The general process flow consists of pretreatment, application of base powder, application of color paint, and application of clear powder.
Water-based wheel paint is environmentally friendly, safe, and offers excellent performance. With a low VOC content-approximately one-fifth that of solvent-based paints-it more easily meets environmental regulations. Water-based paints are flame-retardant and explosion-proof, ensuring high safety. They are comparable to solvent-based paints in terms of gloss, hardness, and weather resistance, while offering superior impact resistance and a reduced tendency to crack.
Key aspects of coating quality control include maintaining a clean, dust-free production environment. Paint viscosity must be strictly controlled to prevent sagging. Additionally, baking temperature and duration require strict control; insufficient temperature or time results in inadequate hardness, while excessive temperature or time can cause the coating to become brittle.
