Permeability testing in plastic packaging is applied to measure oxygen transmission rates and water vapor transmission rates through plastic films and containers. These tests are especially important for companies that produce packaging materials. It is also important for food producing companies to ensure that they use the right barrier materials for foodstuffs in terms of determining product shelf life.
Unlike glass or metal packaging materials, packaging made of plastic is permeable to varying degrees to small molecules such as gases, water vapor, and organic vapor, and to other low molecular weight compounds found in food, such as flavors and additives. As a result of the barrier properties of the material, the transfer of these molecules varies from high to low. These molecules are in solution through the polymer film, Knowing the diffusion and permeability behaviors has gained more and more importance in recent years in terms of the shelf life of polymers and products used in the field of food packaging, where contamination should be prevented.
A portion of the film is cut while the test is being performed. The test is always performed in duplicate and samples are extracted from the same area of the film. One unit measures oxygen transmission rates and the other unit measures water vapor transmission rates. The grease ensures that the sample is placed in the chamber with an airtight seal. The temperature and humidity of the chambers can vary depending on how the materials are stored. Distilled water is used to replace the humidity.
For oxygen testing, oxygen is flowed on top of the film and nitrogen is flowed under the film. During the test, oxygen and nitrogen passing through the film are detected in a sensor that automatically informs the computer. This also applies to water vapor. Water vapor containing nitrogen is flowed onto the film and dry nitrogen is flowed under the film. Any water vapor and dry nitrogen that passes during the test is automatically detected in a sensor that informs the computer.
Depending on the barrier properties of the film, the test can take between one and five days. During the test, a graph is obtained showing the variation of the transmission rate over time.
Our organization also provides permeability analysis services in plastic packaging, with its trained and expert staff and advanced technological equipment, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors.