Seaming or sealing compound is a special material that coats the inside of the End curl. When the can is properly closed, the formed seam will close around the compound – creating a hermetically sealed gasket which will prevent pressure loss as well as block any hazardous materials from entering the can from the outside (e.g., pesticides, mold, pests, heavy metals).
When the seam is closed too tightly, the Compound can smear or overflow and be seen from the outside of the seam.
When there is not enough compound, this can lead to seam bumps as well as prevent the seamed can from being completely sealed!
Things to check with compound:
- Compound weight needs to be monitored regularly (typically by subtracting the average weight of the ends with the dry sealing compound applied, from their weight prior to the application of the compound) using special software such as Symphony.
- The uniformity of the compound needs to be monitored, to ensure that no holes or gaps exist on the ends that had compound applied to them.