Copper is a soft metal that is easily oxidized and stained (note previous post re: green color of Statue of Liberty). Stamped copper parts need to be deburred and cleaned prior to further use in most manufacturing processes.
This picture shows a portion of a copper component of an electronics part. The stamping and cleaning process (part on the left) shows light burrs and clearly visible water spots and staining.
In order to get a clean part for proper electrical contact, the part on the right was vibratory tumbled. The customer wanted a short cycle time and was not interested in a polished or bright surface finish. A Ceramic Angle Cut Triangle was used in order to deburr the outside edges as well as the ID of the holes and other features. The media and parts were tumbled in a compound solution of the Kramco 1030 Mild Acid Cleaner to remove the oxidation and water spots. The end result was a clean, smooth surface finish that met the customer’s requirements. The total cycle time in the tumbler was only 15 minutes.