Factors Of Impacting Oxidation Dyeing For Aluminum Alloy

　　At present,the application of a single color anodized aluminum building profile in practice has been significantly reduced,on the other hand, it has been widely used in electrolysis-coloring oxide film, organic oxide film and porcelain oxide film, hard oxide film and imitation stainless steel oxide film.For technical aspect of oxide film dyeing,there are some factors of impacting oxidation dyeing for aluminum alloy.

1.The Impacting Of Impurity In Electrolysis Solution

　　How well the dyeing for aluminum alloy products most depends on the formation quality of oxide film.Hence,do not neglect the impacting of impurities to oxide film,these impurities which are made up of copper,iron,aluminum,other metal ions and organic contaminant should be removed in time to keep the normal use range for solution.

　　（1）Cupric ion would replace and deposit on the surface of aluminum parts,which caused the oxide film loose hole and reduce its transparency, anticorrosion ability and electric insulation property,so the content of cupric ion can not allow exceed 0.02g/L.

　　（2）Chloridion comes from tap water or cooling water by fracture of cooling pipe,the content of chloridion should under 0.2g/L,otherwise the produtive oxide film will be rough and loose,and the surface of aluminum parts will be etched in severe case.

　　（3）Aluminum ion of electrolyte is growing gradually,when the content is more than 25g/L,the conductivity of electrolyte will decrease,the surface of all aluminum household parts will present white points or nubbly white spots and also reduces the adsorbability of film layer and increases the difficulty of dyeing.

　　（4）Ferric ion of electrolyte is not allow more than 0.2g/L,otherwise dark stripe spots will present.

　　（5）Organic impurities are obstacles for production of oxide film,the dyeing will be uneven and piebald after adsorbing greasy dirt by the film.

2.Factors Of Impacting Oxide Film Dyeing Quality

　　（1）If the pre-treatment degreasing process is not complete, will result in obvious white spots on the film layer, to the coloring difficulties.

　　（2）When the concentration of Sn salt is too low,the dyeing speed will be slow,while its concentration is more than 25g/L,the dyeing speed is quick but not easy to control and produce bigger hue error.

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