Factors affecting water vapour transmission rate

As a professional instrument for testing the barrier properties of product packaging materials, the moisture permeability tester (also called water vapor transmission rate tester) exists. However, during the testing process, some of the details are likely to lead to errors due to human operation, thus making the final data less than extremely accurate and providing wrong data information to the manufacturer.

So, what factors may affect the final test results in the test process? Below, please ask Drick’s R&D engineers to explain in detail.

Factors affecting the water vapour transmission rate：

1, temperature： Different materials in the test, the temperature is set to different. For example, for plastic film or sheet of this material, the required temperature is about 23 ℃, the error range is allowed to be 2 ℃. Therefore, the test process, whether greater than this range, or less than this range, will have a great impact on the final data.

2, humidity： According to the engineers in the R&D department, humidity has a more direct impact on the test data.

3, test time：The test sample should be in the specified temperature and humidity of the test environment, at least the test time of 4 h. If the time is too short, it is likely to lead to the data can be learned from the significance of the small, so that the final production will not play a role in helping; and time is too long, but also because of the changes in the product itself may lead to an increase in the error.

In addition, whether the staff before the test to select the specimen in accordance with the provisions of the test, such as uniform thickness, no creases, folds, pinholes, and more importantly, the specimen area should be greater than the permeability cavity through the area, otherwise these factors will also bring deviation to the test results. Therefore it must be something that manufacturers pay extra attention to.

For this test, our company has independently developed the “Water Vapor Transmission Rate Tester”, which minimizes the systematic errors caused by human errors. And the instrument has a single test can also be measured with three to six specimens, but also to ensure that there is no interference, independent testing, to facilitate the user to carry out a number of specimens of the test needs, so it is the more ideal manufacturers of testing equipment.

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