Anodised aluminium sheet has an important influence on the colour difference of electrolytic colouring

Anodised aluminium sheet has an important influence on the colour difference of electrolytic colouring. The anodic aluminium oxide plate has a very important influence on the colour difference of electrolytic colouring, especially in the production process of vertical oxidation line it is easy to have two colours, the vertical oxidation tank is 7.5m deep, the upper and lower tank liquid is easy to produce temperature difference, the temperature has an important influence on the anodic oxidation, the temperature is high, the dissolution of the oxidation tank liquid on the oxide film is intensified, the pore size of the surface of the porous type anodic oxide film will increase, on the contrary, the surface of the porous type anodic oxide film pore size is smaller.

In addition, at high temperatures, the porosity of the anodic oxide film is higher and vice versa. Electrolytic colouring is the electrochemical reduction of metal ions in the colouring solution on the surface of the barrier layer within the micro-pores of the oxide film, causing the metal ions in the colouring solution to be deposited at the bottom of the anodic oxide film pores and to scatter the incident light to reveal different colours, the more material deposited in the micro-pores, the darker the colour. Under the conditions of passing the same amount of electricity, the temperature is high and low on the part of the deposition of equal amounts of metal or metal compounds, for high porosity and surface pore size, the average deposit per hole to less, 5052 aluminum plate so its colour is relatively light, and vice versa, the colour is darker, thus causing the coloring material two colours.

5052 aluminum plate in the anodic oxidation process, the electrical conductivity of the oxide film has an impact, will also cause the coloring material to produce colour difference, the problem is mainly in the horizontal production line is easy to appear, mainly due to oxidation billet material in the oxidation before the row process, the clamp material is not tight, resulting in individual material conductive bad, thus making its oxide film relatively different, and then by coloring, it will produce colour difference.