Moisture Barrier Property Test Solution of Aluminum Plastic Composite Film Used for Medication

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.

Flexdurability tests of specimens are performed according to ASTM 392. Thespecimens of flexible materials are flexed at standardatmospheric conditions (23°C and 50 % relative humidity),unless otherwise specified. Flexing conditions and number andseverity of flexing strokes vary with the type of structure beingtested. The flexing action consists of a twisting motion followed,in most cases, by a horizontal motion, thus, repeatedlytwisting 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 LabthinkFDT-02 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.

Figure 1: Aluminum Plastic Composite Film after Flex Durability Test

Step 2: Water Vapor Transmission Rate Test

Add certain amount of distilled water into the test dish of LabthinkW3/030 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 packagingespecially in production and transportation process.

For more details about FDT-02 Flex Durability Tester and W3/030 Water Vapor Transmission Rate 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.

Heat Seal Strength of Medical Blister Packaging

Blister packaging is one of pre-formed plastic packaging, which is featured with high barrier property and widely used for protecting products against external factors, such as humidity and contamination for extended shelf life.Blister package usually has a backing of paperboard or a lidding seal of aluminum foil or plastic.

In medical industry, blister packaging is commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges.The medicines are held in the blister cavities, which  are separated medicines from each other. Even though one blister cavity is broken, others can keep intact. Therefore, heat seal strength of the paperboard or aluminum foil should be adequate. Otherwise when one tablet or capsule is removed from the blister package, other blister cavities may be broken and then medicine may be oxidized and damped. Therefore it is necessary to test the heat seal strength of the medical blister packaging to guarantee the quality of medicines contained inside.


How to know and make sure if the blister packaging has enough seal strength？ What manufacturers can do during the packaging producing? We will discuss these with assistance of a Tensile Testing Machines.

Step 1: Seal the rigid PVC sheet and aluminum foil with Labthink HST-H6 Heat Seal Tester under specified conditions (sealing temperature 155±5℃, sealing pressure 0.5MPa, dwell time 1 second).

Step 2: Cut 3 pieces of specimens whose length should be 15mm.

Step 3: Mount the prepared specimen in the sample grips of XLW (M) Auto Tensile Tester. Select test speed 200 mm/min and then start test. When test is finished, the instrument will calculate and record the test results automatically.

According to the test results given by the instrument, the manufacturer can determine whether the blister package can meet their requirements for packing of medicines.

For more details about XLW (M) Auto Tensile Tester and HST-H6 Heat Seal 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.

Oxygen Barrier Property Test Solution of Black and White PE Film for Liquid Milk

Liquid milk is an important part of many people’s diet. Since a large amount of fat and protein are contained in milk, it is easily oxidized and, as a result, the quality of the milk can be compromised within its shelf life. A main cause of oxidation is potentially thepoor oxygen barrier property of the packaging materials used for liquid milk. Therefore,it is necessary to perform oxygen permeability tests with a suitable instrument to evaluate whether the film or bag has adequate oxygen barrier properties.

Currently coextruded black and white film made of PE is widely used in package for liquid milk. Such material featuresopaque, low cost, portability and environment-friendly characteristics, for which it is popular in packaging for liquid milk. The barrier property of some black and white film is quite ordinary and the shelf life of the milk using such material is usually about 30 days. In contrast, when a material with ultra-barrier property is used as the packaging material for liquid milk, the shelf life can be extended to 90 days. Therefore, it is recommended that milk manufacturers to select suitable packaging materials by testing their oxygen permeability with testing instrument.

There are two methods for oxygen permeability test. They are the differential pressure method and the equal pressure method. The former will be elaborated in this article.

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. 

Labthink VAC-V2 Gas Permeability Tester adopts differential pressure method, which is used as the testing instrument to test the oxygen transmission rate of the black and white PE film specimens in the tests mentioned hereinafter.

The tests can be performed according to the following procedures.

1)    Condition the black and white PE film samples in a desiccant container at 23℃ for 48 hours. Then cut 3 pieces of round specimens whose diameter should be 97mm.

2)    Mount the specimens in the test chamber and clamp the specimens tightly.

3)    Set test parameters including control parameters and specimen parameters.

4)    Start the test. The test humidity can be adjusted in testing process if necessary.

5)    The tests will be performed automatically and test results can be obtained when the tests are finished.

According to the test results, the manufacturer or user of black and white PE film can determine whether the packaging material can meet their requirements for liquid milk package.

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.