|
At present, manual spray paint is used as primary method in external painting of foamed aluminum. The method has many disadvantages, such as serious environmental pollution, possible harm for human health and low utilization ratio, especially in that it can’t paint the external deep recession completely. Compared with it, the electrophoresis painting holds advantages in high utilization ratio, ready operation, realizing painting automatically easily, low pollution, even paint film thickness, strong corrosion resistance and process insusceptibly by painted object shape. Thus electrophoresis painting is used widely in metallic external coating. Among its types, the epoxy resin type possesses high adhesion and outstanding corrosion resistance. The paper discusses the film forming process of cathodical electrophoresis painting on the foamed aluminum and confirms the optimal process conditions.The topic utilizes single factor experiment to gain the optimal process conditions of foamed aluminum cathodical electrophoresis painting and ensure the optimal process conditions of epoxy resin type cathode electrophoresis painting:the electrophoresis voltage is 90V, electrophoresis time is 4min, pH value of tank liquor is 6.5, temperature of tank liquid is 35℃, pole ratio is 2:1, interpole gap is 15cm, drying temperature is 140℃and drying time is 15min. It studied the influence of these factors, including electrophoresis voltage, electrophoresis time, pH value of tank liquor, temperature of tank liquid, pole ratio, interpole gap, drying temperature and drying time, on appearance and properties. The neutral salt mist experiment and boiling water resistance experiment test the corrosion resistance property of paint film. The synthetical paint film holds preferable appearance and corrosion resistance according to the optimal process conditions and through corroded for 40h under salt mist of 5% NaCl and dipped for 3h in deionized water at 90℃.
|