Present Situation and Trend of Permeation Testing


With the strengthening of testing on food and pharmaceutical packaging materials, the promotion of permeation testing has found favorable opportunity.



1. Present Situation

At present, the common instruments for permeation testing are of differential pressure method for gas transmission rate testing and weighing method for water vapor transmission rate testing. Besides, equal pressure method for gas transmission rate testing and electrolytic method for water vapor transmission rate testing have also found a certain portion of applications.



2. Main Focuses

Firstly, market should evaluate the precision of the instruments scientifically with a positive forward-looking view. It’s sure that with the continuous precision development, human interference on the testing data has become more prominent. The experiences and skills of the instrument operators would sometimes become the key factors influencing the data stability and repeatability.



Secondly, the focus of instrument selection. Some users, when selecting equal pressure instruments and sensor method instruments, concern especially whether the sensor of the instrument is a absolute value sensor or a relative value sensor.The author has long been experimenting with electrochemical sensor oxygen permeation testers, and the testing specimens are of varied permeation properties. According to actual use in recent years, it’s out of question that the sensor can work stably for more than 3 years (much longer than the description in some reports), only if the users operate normally without operational errors. Furthermore, the life span of absolute value sensor is relatively short which can be further proved by the newly issued standard.



Thirdly, how to apply measurement authentication for the permeation testing instruments has always been the concerned by the quality inspection labs. Permeation property testing instruments are different from traditional mechanical and chemical testing instruments.



Now, the indexes of permeation testers can satisfy requirements for packaging industry completely, and have made great progress in container package testing. At the same time, new technologies and new methods have been applied increasingly, with only a few notable issues in instrument selection and application. Development of special testing instruments and expansion of testing substances are the two tendencies in the permeation testing field. It’s foreseeable there will be extensive and bright future for permeation testing.


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