The aluminum profile is too large
Excessive swing in the tank during operation. Lead to the big contact difference of edges and the center parts.
Prevention method: Reduce the amplitude of aluminum profile swing during anodizing, or static processing. But when the liquor temperature is too low, the aluminum profile is easy to appear spot.
Improper process operation.
the aluminum profile alkali corrosion treatment is not complete, part of aluminum is primary anodized film, the dirt has not been remove clearly
Didn’t get light treatment immediately after alkali corrosion, the aluminum profile surface is still alkaline
The aluminum profile contact with foreign bodies in the process of transmission.
Prevention method: Be more careful in the operation
When the anodized color is not even, we have to find the reasons from many aspects, take targeted measures to solve.