4. Observed crimping faults, correlation between tightness and dimensional measurements of crimps

4.1 Main crimping defects and their causes

Dimensional defects (measured dimensions) do not represent the majority of defects. Many of the defects encountered are visual defects observable on the outside of the seam (sharp edges, roller or mandrel marks, sharp seams, etc.) or defects observed visually after stripping (corrugations, folds, pimples, etc.).

• The causes of these crimping defects are divided into :

  • incorrect crimper settings;

  • occasional technical problems (jamming, poor centering of feeder bottoms, etc.);

  • quality defects in the cans themselves or in the crimping ends: damaged crimping edge, poorly applied seam,...