PROCESS AND APPARATUS FOR TESTING MULTI-LAYER COMPOSITES ANDCONTAINERS PRODUCED THEREFROM

摘要

The invention relates to a method and a device for detecting gas-permeable damage points in an electrically non-conductive layer which can be embodied as a single layer or a multi-layered composite comprising at least one conducti ve layer. A test piece is arranged in a test chamber. The layer which is to be tested has an electrically conductive layer on the one side and a gas chambe r on the other side. The gas in the gas chamber is ionised at a pre-defined lo w pressure by means of an electric gas discharge. A counter electrode which is arranged in the gas chamber forms a test current circuit with a voltage sour ce and a measuring device. If the layer which is to be tested contains a damage point, the gas discharge is maintained and a direct current is measured in t he test current circuit, said current acting as an indicator for a damage point . Due to said method, it is possible to detect damage points are liquid tight or which are only present in a non-conductive layer in a multi-layered composit e. The inventive method is used in containers for sensitive pharmaceutical preparations, if the containers are subjected to exacting requirements with regard to the impermability thereof during a storage period or application period lasting several months.