The pharmaceuticals are easily deliquesced after absorbing moisture, for which the packaging materials should be of high moisture barrier property. Aluminum plastic composite film is widely used in pharmaceutical packaging which can help extend the shelf life and guarantee the quality of the pharmaceuticals.
However, the aluminum layer may be folded during package forming, product filling, heat sealing and transportation processes and as a result the barrier property (both oxygen barrier property and water vapor barrier property) may be compromised. Therefore it is necessary to test the water vapor permeability of aluminum plastic composite film after flex durability tests to guarantee its performance of protecting the pharmaceuticals from deliquescing and deterioration.
This article provides simplified testing procedures for moisture barrier property of aluminum plastic composite film for your reference.
Flex durability tests of specimens are performed according to ASTM 392. The specimens of flexible materials are flexed at standard atmospheric conditions (23°C and 50% relative humidity), unless otherwise specified. Flexing conditions and number and severity of flexing strokes vary with the type of structure being tested. The flexing action consists of a twisting motion followed in most cases, by a horizontal motion, thus, repeatedly twisting and crushing the film. The frequency is at a rate of 45cpm.
Then the water vapor permeability of the specimens after flex durability tests will be tested. There are two categories of test methods for water vapor transmission rate i.e. gravimetric method (also known as cup method and divided into dry cup method and wet cup method) and sensor method (including electrolytic sensor method, infrared sensor method and humidity sensor method).
Let’s take a look at the detailed testing procedures.
Step 1: Flex Durability Test
Mount the aluminum plastic composite film specimens in Labthink C681M Flex Durability Tester and then perform full flex for 6 minutes i.e. 270 cycles. Condition the specimens after flex durability test (3 of each kind of specimen whose diameter should be 74mm) in the desiccant container at 23℃ for 48 hours.
Step 2: Water Vapor Transmission Rate Test
Add certain amount of distilled water into the test dish of Labthink C360M Water Vapor Transmission Rate Tester. Then mount the specimen in the mouth of the test dish. Place the test dish into the test chamber and close the door. Then set test parameters and start test. The test will be performed automatically and the test results will be given after test.
By testing the water vapor transmission rate after flex durability tests, the user or manufacturer can determine whether the WVTR of the aluminum plastic film meet the requirements for pharmaceutical packaging especially in production and transportation process.
For more details about C681M Flex Durability Tester and C360M Water Vapor Transmission Rate Tester, please visit www.labthink.com