Permeation, leak tightness, barrier properties
At Innoform we measure the permeation of gases or water vapour through films, coated papers and fabrics, containers, bottles, bags or packaging components under a wide range of climatic conditions. Through many special measurements for the evaluation of packaging components, such as shrink-wrapped parts, opening aids, laser perforations and valves with regard to tightness and permeation behaviour, we have been able to acquire a wealth of experience in recent years. Basic research on the influence of heat treatment and other stress conditions on the barrier and tightness of packaging materials round off our field of activity. Please contact us, we will be pleased to advise you on the selection of the optimum test conditions for your task.
In the following, we would like to briefly explain how our tests are of increased relevance with regard to the tightness of packaging, for example with regard to the shelf life of food. First of all, some basic information about the process of permeation: in a first step, the foreign molecule is absorbed on the surface of the material, then the diffusion of the molecule through the matter takes place, and finally the molecule is desorbed on the other side of the material. This mechanism is crucial for the speed of permeation. Accordingly, the permeation coefficient P is formed from the product of the diffusion coefficient D and the solubility coefficient S. With the help of a permeation coefficient test, statements can finally be made about the tightness of a package.
At Innoform, we can use a permeation test to determine the permeation coefficient of a wide variety of substances, whether nitrogen, water vapour, carbon dioxide or oxygen. For example, the oxygen permeation of films, laminates, coated papers and aluminium composite films is tested as follows:
The oxygen transmission rate (OTR) for the tightness of packaging, bags, moulded parts, bottles etc. is tested in the following tests:
For the carbon dioxide permeation test, a manometric method is used in the same way as for the nitrogen permeation test. In order to test the water vapour transmission rate (WVTR), two different permeation methods are used in most cases:
Once you have obtained the permeation coefficient of your material through the permeation check thanks to the competent team of experts, you can develop or adapt the materials of your product accordingly on the basis of this to enable complete or partial elimination of permeation. You don't have time to wait for the test results of the Innoform permeation analysis? No problem. You can already get a first overview of the tightness of your packaging thanks to our Innoform flashover permeation calculator. Do not hesitate to contact us if you have further questions regarding the permeation calculator and the right test procedure to check the tightness of your packaging or if you need even more information on the subject of permeation.