Vacuum loss in cans can be caused by several factors. One of them is the bulging or buckling of the base or lid of the container due to excessive internal pressure, which can lead to the seam opening and allow contaminants to enter, especially during cooling, when a vacuum is formed in the cans. In addition, the presence of convex tops and bottoms on cans may be indicative of a possible alteration of the contents and a sign of vacuum loss.
Other factors that can cause vacuum loss include overfilling, which can put too much pressure on the seams or closures during processing and reduce the effectiveness of the heat treatment, as well as the generation of initial cracks due to internal pressure effects or handling actions, which can result in leakage of the liquid contained in the can.
In addition, mishandling of the cans during the production process, such as improper handling leading to banging or scratching, or the use of poorly calibrated machinery causing chipping and loss of lacquer, can also contribute to vacuum loss.