Process and apparatus for testing multi-layer composites and containers produced therefrom

摘要

The invention relates to a process and an apparatus for detecting gas-permeable damaged points in an electrically non-conductive layer which can exist as a single layer or as a multi-layer composite with at least one conductive layer. A test subject is disposed in a test chamber. On the one side of the layer which is to be examined is an electrically-conductive layer, and on its other side is a gas environment. The gas in the gas environment is ionized at a given pressure by means of an electrical discharge. A counter-electrode disposed in the test chamber forms a test current circuit, together with a voltage source and a measuring device. If the layer which is to be tested contains a damaged point, a distinct current is measured in the test current circuit, if the gas discharge is maintained, which serves as an indicator for a damaged point. The process allows the detection of damaged points which are fluid-tight, or which are only present in a non-conductive layer in the case of a multi-layer composite. The process is used in the case of containers for sensitive pharmacological preparations if rigid requirements are placed on these containers with regard to their integrity during storage times or periods of use which extend over a plurality of months.