Knuckling
As the can entered the screw of our seamer, instead of driving forward, the back side of the can buckled and stopped moving forward which in turn compromised the integrity of the can itself. Once it entered the dwell for a seam, it became crunched under the force of the lifter due to the compromised rigidity. The video below shows a can that as a result, did not even make it fully onto the lifter. Knuckling is most commonly seen in cans that are shrink sleeved, especially if that wrap is a matte finish.
Order of Operations:
Check rail placement of the 2 outer seamer rail adjustment points, they should keep the can very secure.
Check seamer screw for any amount of stickiness or residual sugars causing added friction as the can moves from under the lid dropper onto the transfer plate.
Check the seamer nose roller to confirm the bottom of the can is not tripping over the transfer plate.
​Check the lift pad to make sure the can is not tripping over it as well on its way into the dwell.​
At times, the issue is actually being caused by the filler index screw post fill cycle. They leave the filler area already dented on the back side. If this is the case, set index screw offset to 0 on the automatic operations screen to instantly solve the issue.
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If the problem persists, applying lubricant to the screw will most often remedy the issue. Whether you use silicone, marine grease or dish soap applied with a pump, reduction of friction in any way will help resolve the issue. Contact the Codi Service Team for insight on how this can be done.
