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Cap & Container Issues
Good Container Lip/Liner Contact
Good contact between the liner material and the container lip is very important. This goes hand in
hand with the amount of torque applied, but can be a problem even when the torque levels are
good. The land area of the container should be wide enough and rigid enough to support the pressures
and heating required for a good seal.
Poor Container Lip/Liner Contact
A thin or weak land area can cause poor contact between the liner material and the container lip.
When the land area is too thin there may not be enough rigidity in the land area to support the
pressures and heat required for a good seal.
Container Lip Deformations
Gaps between the land area and liner material can be the result of any number of problems, from
mold imperfections to container material issues. Regardless of the cause, any gap between the liner
and container land area may cause overheating and failure of the seal. A gap caused by saddles on
the land area and a gap caused by a protrusion are shown. These defects can be detected on the
container land area before the container is capped.