Moisture Resistance Test of Blister Packaging

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Blister packaging is a form of packaging which is made of transparent plastic sheet or aluminum plastic composite sheet with blisters and covered with aluminum foil. Because each blister is independent from others, one damaged blister will not affect the sealing of other blisters. Therefore, taking out the product in one blister will not affect the protective effect of blister packaging on other products. The advantages of blister packaging and the popularization of blister packaging technology make the use of blister packaging expand from packaging for tablets, capsules, pellets and other drugs to the packaging of food, cosmetics, electronic devices and other products. Products such as medicine and dried food are prone to absorb moisture and agglomerate, and electronic products are sensitive to water vapor, therefore, blister packaging should have good moisture barrier performance.

Test sample

In this test, a type of blister packaging composed of plastic hard sheet and aluminum foil is used as the test sample to test its moisture-proof performance. The Instrument used in this test is Labthink C390H Water Vapor Transmission Rate Test System.

Test standard

The moisture barrier performance can be interpreted by water vapor transmission rate. The low water vapor transmission rate indicates that the material has good moisture barrier performance. In this paper, the infrared sensor method is used to test the water vapor transmission rate of samples. The test process is in accordance with ASTM F1249 Standard Test Method for Water Vapor Transmission Rate through Plastic Film and Sheeting Using a Modulated Infrared Sensor.

Test principle

The infrared sensor method is based on the principle that water molecules can absorb infrared light quantitatively. The water vapor transmission rate of the material can be obtained by measuring the attenuation of infrared light. The test chamber of the instrument is divided into two parts by the film or the container samples. For the film samples, the upper chamber flows nitrogen with a certain humidity, the lower chamber is dry nitrogen, the outer part of the container sample is nitrogen with a certain humidity, and the inner part is dry nitrogen. Under the effect of the humidity difference, the water vapor penetrates from the high humidity side to the low humidity side through the sample, and carried by the nitrogen to the sensor for analysis to obtain the water vapor transmission rate of the sample.

Test procedure

(1) Cut three independent blisters from the sample, take three container sample clampers, insert three blisters respectively, and seal them with sealant, as shown in Figure 2.

Grap for blister pack

(2) Install the clamped sample in three test chambers of the instrument, and seal the sample and the clamper with a sealed bag filled with nitrogen with a certain humidity. Use the temperature control cover to control the temperature of the whole test unit.

(3) Set the sample name, test temperature, test humidity, test mode and other parameters, click the test option to start the test. The equipment is tested according to the set parameters, and the test results are displayed after the test.

Test result

The arithmetic mean of the test results of three blisters is 0.000341 g/(pkg·d).

Conclusion

Good moisture barrier performance is one of the important factors to ensure the quality of content of blister packaging. In this paper, the water vapor transmission rate of the blister packaging samples was tested to determine the moisture barrier performance of the samples. The test process is simple, the instrument is easy to operate, the degree of intelligence is high, the parameter control is stable, the accuracy of the test results is high.