Compared with normal zinc anodizing treatment, it is feasible to generate qualified zinc anodizing film at about twice the high speed and then carry out uniform electrolytic coloring.

On the premise of obtaining a satisfactory oxide film, the relationship between film thickness and time was collected by changing the conditions of anodic oxidation of zinc.

The oxidation time was shortened to 1/20 when the sulfuric acid concentration and current density increased to 2 times

Under the above conditions, due to the increase of current density but no increase of applied voltage, the cell size decreases slightly and the porosity increases, but the micropore diameter of anodic zinc oxide film changes little.

For this reason, the performance of anodized zinc film has not changed, and it can be considered that electrolytic coloring treatment is also very good.

It is generally believed that the temperature rise of zinc anodic oxidation bath is mainly caused by joule heat caused by current. The heat of anodic oxidation reaction of zinc on aluminum electrode does not take a major share in the calorific value. For example, oxalic acid solution at 70V is about 2%, while sulfuric acid solution at 15V is about 18%, so the calculation of calorific value is mainly obtained by the square of the current multiplied by the resistance of the bath solution.

As the concentration of sulfuric acid solution increased from 150g/L to 300 years L, the resistance of the solution decreased from 1.712 /m to 1.011./m, that is, to about 60%. If the current is doubled, the heat is not four times greater, but actually only two and a half times greater.

The lower actual calorific value means that high speed anodizing of zinc requires additional cooling capacity, but not as much as theoretically expected. Therefore, the advantage of high speed zinc anodizing treatment is that it can reduce the capacity of cooling equipment. However, it is more important to ensure that the electrical contact is in good condition.