A mushroomed can flange refers to a flange that has been excessively formed, resulting in a long body hook. The detection of this condition is not possible until the seam is stripped to inspect the body and cover hook. It is a significant contributing factor to the false Seam problem discussed in a previous post.

CAUSES

(a) Excessive pressure from the lower chuck spring during can manufacturing.
(b) Worn lower chuck groove (only applicable to can manufacturing).
(c) Excessive pressure from the lift cylinder on the filler.
(d) Damage to the can flange in the can handling system.

REMEDIES

(a) Decrease the pressure from the lower chuck spring.
(b) Replace the lower chuck plates with new ones.
(c) Verify and adjust the lift cylinder pressure to the correct level.
(d) Inspect the entire can handling system.