Aluminum alloy wheel coating process

Abstract

The invention provides an aluminum alloy wheel coating process, which ensures that wheels produced with the coating process have the characteristics of uniform thickness of paint films and good corrosion resistance. The coating process comprises the following steps of: front surface treatment, powder spraying, powder curing, paint spraying, paint curing and cooling, wherein the chromium-free passivation is utilized, an electrostatic rotary bell spray gun is used to spray paint on work-pieces, the construction voltage of a rotary bell is controlled between -50kV and -60kV, the rotation number of the electrostatic rotary bell is controlled at 25-32 kr / min, the paint spraying quantity of the rotary bell spray gun is 70-100cc / min, the pressure of forming air is controlled at 0.1-0.5MPa, and the distance from the spray gun to the work-piece is between 150mm and 180mm. Because of the optimization of the technological parameters of the processes of chromium-free passivation, curing and paint spraying, the coating performance of the wheels is improved, the unilateral corrosion in a salt spray test does not exceed 2mm, and the thickness of the paint film is uniform.

Description

technical field [0001] The invention relates to a coating process, in particular to an aluminum alloy wheel coating process. Background technique [0002] At present, the coating process of aluminum alloy wheels is generally: pretreatment-drying-dusting-curing-spraying paint-spraying lacquer-curing, in which the pretreatment process is chrome-free passivation, generally using 16-22 points, passivation The curing effect of paint and powder is generally heated by gas hot air circulation, and the temperature in the furnace is set at 170-175°C, so the curing effect is uneven; the paint spraying process generally adopts air spraying or electrostatic spraying, and the process parameters of the spray gun are generally gun The distance is 15cm±2, the amount of spraying paint is 30-50cc / min, the atomization pressure is 0.05-0.25Mpa, and the forming pressure is 0.1-0.2Mpa; for the wheels produced by the existing coating process, the corrosion width of the salt spray test is generally ...

AI Technical Summary

Problems solved by technology

[0002] At present, the coating process of aluminum alloy wheels is generally: pretreatment-drying-dusting-curing-spraying paint-spraying lacquer-curing, in which the pretreatment process is chrome-free passivation, generally using 16-22 points, passivation The curing effect of paint and powder is generally heated by gas hot air circulation, and the temperature in the furnace is set at 170-175°C, so the curing effect is uneven; the paint spraying process generally adopts air spraying or electrostatic spraying, and the process parameters of the spray gun are generally gun The distance is 15cm±2, the amount of spraying paint is 30-50cc / min, the atomization pressure is 0.05-0.25Mpa, and the forming pressure is 0.1-0.2Mpa; for the wheels produced by the existing coating process, the corrosion width of the salt spray test is generally less than unilateral corrosion. More than 2mm, bilateral and not exceeding 4mm, the thickness of the paint film is generally 90um-170um