In-line-tightness

n order to assure a high product quality and a long shelf-life MAP-packages are becoming increasingly popular. The product-specific atmosphere inside the package differs from the ambient air. The resulting differences in partial pressure trigger gas exchanges as soon as there are minimal pin holes or capillaries in the package. The MAP-packages would then lose their desired protective effect.

Based on the results of the AiF-project “tightness of pouches“, studies suggest procedures based on test gas as a main approach to measure/determine tightness.

By adding test gas into the packaging atmosphere, escaping test gas can be detected due to resulting partial pressure differences. The aim of this project is to test whether leakages and quality defects in food packages can be detected and measured with test gas based methods.

Within this project an experimental setup for the test gas based tightness testing will be designed. Through this test equipment the correlation between testing period, detection limits, test chamber and package volume will be investigate. In pre-tests an ideal package with predefined leakages will be investigated. Subsequent to the pre-tests, the results will be transferred to real packages such as pouches.

The investigations should enable quantitative statements to the following points (for instance):

• required testing period for the repeatable detection of predefined leakages
• achievable cycle times depending on test period and test chamber volume
• what is the maximum output by usage of a 100% inline-tightness-control

The interpretation of the results will provide the limits of the non-destructive test gas based inline testing method.

With the support of an inline test for tightness of packages it is possible to eliminate arising quality defects as fast as possible. This will minimize the production of faulty products and the consequences of untight packages such as complaints, damage to image, loss of customers or increasing costs.