Method for coating the visible surfaces of motor vehicle wheel rims

A method for coating the visible surfaces of motor vehicle wheel rims made of aluminum or steel, in which

• a polymer primer layer (A) is first applied to the mechanically processed metal surface of the wheel rim, which layer evens out the irregularities of the mechanical processing,
• then a polymer intermediate layer (B) is applied to the surface of the polymer primer layer (A),
• then a decorative layer (C) is applied to the surface of the polymer intermediate layer (B), which decorative layer comprises a thermally cured polymer layer with embedded platelet-shaped metal pigments, which cover the visible surface of the decorative layer (C),
• and finally the surface of the decorative layer (C) is covered by a polymer topcoat (D),
• wherein
• the polymer intermediate layer (B) is produced with a high-gloss surface with a gloss grade according to DIN67530/ISO2813 of more than 95,
• the decorative layer (C) is applied by wet spraying with a layer thickness of a maximum of 2 μm to the high-gloss surface of the polymer intermediate layer (B) and is dried there at ambient temperature, and
• prior to the application of the polymer topcoat (D), the decorative layer (C) is fixed on the surface of the polymer intermediate layer (B) by a thermal aftertreatment such that it adheres to the surface with a cross-cut tear strength according to DIN EN ISO 2409 of Gt=0 to Gt=2.