Container production method and device providing container wall surface coating and determining wall gas permeability of randomly selected containers

A method for coating blow-molded containers, comprising the steps of:

• initially preconditioning each container by binding an analytical gas in the area of the wall;
• subsequently applying a barrier coating on an inner surface of the wall of the containers;
• randomly sampling some of the coated containers;
• and
• testing each of the sampled containers in a testing device for determining gas permeability of the walls of the containers, the testing including:
• measuring a concentration of analytical gas in an analytical space in an interior cavity of each of the sampled containers that is at least partially bounded by the barrier coating, which analytical gas escapes from the area of the wall of the container into the analytical space and which was bound in the area of the wall before its escape into the analytical space, the measurement of the analytical gas being carried out at a pressure that is selected to be substantially equal to ambient pressure so that there is no pressure difference between the interior of the container and the outside of the container;
• introducing a carrier gas so that the carrier gas flows through the interior cavity during measuring of the analytical gas;
• prior to the measuring, flushing the interior cavity with the carrier gas so that the analytical space is free of analytical gas;
• and, undertaking metrological determination of the analytical gas within the carrier gas so as to achieve analysis times on the order of a few minutes.