The reason for the bright bands and small black spots on the surface of the aluminum plate

Bright bands refer to

Poor quality of roller grinding;

Insufficient process lubrication;

Bright bands are caused by rolling narrow material first and then wide material.

Black spots are

When the emulsion is lubricated, the emulsion is not clean enough, resulting in small black spots on the surface of the aluminum plate;

Sometimes there are scratches on the surface of the aluminum plate, which will also have small black spots;

Scratches and impurities in the metal will also produce small black spots.