Product entrapment

This defect occurs when canning solid food, and in particular fish, where bones or other materials can remain or overhang the flange, causing the material to remain trapped inside the seam and keeping it open. This can cause the double seam to either be “Thicker” (excessive Seam Thickness) or cause Droops or Vees.

This type of defect usually requires visual seam inspection in order to detect.