With the fast development of transport service and improvement of storing technique, the commercial products such as food, medicines, and healthy products etc. can be sold very far away from their places of origin. For example, in China, from north to east and from west to east, the environments of different regions are remarkably various with different temperature and different humidity. For the same product, in winter, it may be more liable to be oxidized and get deteriorated in the southern area than in the northern area of China. Therefore, when selecting packaging materials, it is necessary to test the oxygen barrier property of those materials at different temperatures so that they can adapt to the temperature change and protect the product from oxidization properly.

PE/PET composite film is very common packaging material used for the products mentioned in the paragraph above. This article will take PE/PET composite film as an example to explain how to test the oxygen barrier property of the same packaging material at different temperatures.

The test specimens are tested at 10℃, 0%RH and 30℃, 0%RH. The testing instrument is Labthink’s VAC-V2 Gas Permeability Tester. With differential pressure method, the sample is mounted in a gas transmission cell so as to form a sealed semi-barrier between two chambers. One chamber contains the test gas at a specific high pressure, and the other chamber, at a lower pressure, receives the oxygen. The oxygen will be detected by either a manometric sensor or a volumetric sensor.

Figure 1. VAC-V2 Gas Permeability Tester

The tests shall be performed according to the following procedures.

l  Cut three pieces of specimens from the provided PET/PE composite film samples with sample cutter. The diameter of the specimen should be 97 mm. Condition the specimens at 23±2℃ for 48 hours.

l  Measure the specimen thickness. Measure at least 5 points and calculate the average value.

l  Apply a thin layer of vacuum grease on the test chamber. Lay a piece of filter paper on the central area of test chamber. The diameter of the filter paper should be 65mm. The filter paper can support the test specimen and protect the lower pressure chamber from contamination. The paste the specimen on the test chamber and close the upper chamber and tighten it.

Figure 2. Clamp the Specimen

l  Set specimen thickness, test temperature (10℃), test humidity (0%RH) and other test parameters.

l  Switch on the vacuum pump and temperature control device. Click Start Test to start the tests.

l  The test results will be calculated and displayed automatically.

l  Replace specimen and repeat the above procedures except setting test temperature (30℃) and test humidity (0%RH).

By testing the oxygen barrier property at different temperatures, the manufacturer can select proper packaging materials to ensure the quality of their products within shelf life in different environments.

For more details about VAC-V2 Gas Permeability Tester, please visit www.labthink.com

About Labthink Instruments Co., Ltd

Labthink Instruments Co., Ltd is one leading supplier of packaging testing instruments, which is headquartered in Jinan, China and operated in Boston, U.S.A.