Defects
The production of a high-quality double seam is dependent on several factors, including conformity to the set can and end specifications, the quality of the seamer tooling used and its compliance with the can and end being used, the condition of the seaming machine and the setup of the seaming rolls, lifter pressure and other components. When the machinery is set up correctly and the incoming materials (cans, ends, tooling, etc.) comply to the set specifications, the result should be[2] ideal first and second operation seams.
A problem in any one of these factors and others can contribute to seam defects that have an adverse affect on the ability of the can to withstand foreign contamination and keep the product from leaking or reduce its shelf life. Below is a list that can be used as a reference