Test Method for Organosilicon Film Gas Permeability

Abstract: Organosilicone film is a new type of polymer material with excellent performance. The gas permeability is an important factor affecting the application of organosilicone film. In this paper, the principle of differential pressure method is used to measure the carbon dioxide transmission of a kind of organosilicone film, and the test principle, equipment parameters, application scope, test process and other contents are introduced, which provides a reference for the test of other gas barrier properties of organosilicone film.

Keywords: organosilicone film, carbon dioxide transmission rate, differential pressure gas permeability tester, permeability, differential pressure method

Organosilicon film is a type of semi-inorganic and semi-organic polymer material. It has good heat resistance, low-temperature flexibility, high dielectric strength, chemical inertness, permeability and selective permeability. It can be applied in electronic skin, intelligent sensor, functional packaging, protective film, wound dressing, scar paste, gas separation film in electronic, agriculture, manufacturing, pharmaceutical industry and other fields.

In the above applications of organosilicone film, gas permeability is an important factor affecting the application effect of the film. For example, wound dressing with good permeability is conducive to wound healing, and good permeability selectivity is conducive to improving the separation effect of the separation membrane. The permeability of the organosilicone film is related to the molecular structure and the morphological structure of the film. Therefore, the test of the permeability of the organosilicone film can provide a data reference for adjusting the production process of the film.

Test Sample

In this test, a type of organosilicone film is used as the test sample to test the carbon dioxide permeability of the sample.

Standard

At present, the principle of differential pressure method is mainly used to test the carbon dioxide transmission of flexible plastic packaging materials. The test process is based on ISO 2556 – Plastics — Determination of the gas transmission rate of films and thin sheets under atmospheric pressure — Manometric method

Test Instrument

In this paper, the VAC-V2 Differential Pressure Gas Permeability Tester is used as the test instrument to test the carbon dioxide transmission rate of samples. The test instrument is independently developed and produced by Jinan Labthink Instruments Co., Ltd.

Test Principle

The differential pressure method refers to the measurement of the gas transmission rate through the change of pressure during the test. The clamped sample divides the test chamber of the instrument into upper and lower chambers, the upper chamber is filled with the gas to be tested (in this paper, the gas to be tested is carbon dioxide), the lower chamber forms a vacuum environment by vacuuming, the gas to be tested penetrates into the lower chamber from the upper chamber through the test sample, and the gas pressure in the lower chamber changes, and the pressure sensor in the low-pressure chamber monitors the pressure change in the low-pressure chamber in real-time, and calculates the gas transmission rate with value of the test gas penetrates the sample per unit area in unit time.

Figure 1 VAC-V2 Differential Pressure Gas Permeability Tester

Test process

(1) Three specimens with diameter of 97mm were cut from the organosilicon film.

(2) Apply a layer of vacuum grease evenly around the test area of the three test chambers of the instrument, place filter paper in the test area to support the specimen, and then place the sample on the test chambers respectively, press gently to drive away the bubbles between the specimen and the test area. Tighten the chamber cover.

(3) Connect the equipment to the carbon dioxide source. Set the sample name, sample thickness, test mode, test temperature, humidity and other parameter information on the control software of the instrument, click “test” and switch on the vacuum pump to start the test. The instrument runs the test according to the set parameters, and the test results are displayed after the test.

Test Results

The results of the three samples were 2.671×10⁵cm³/(m²·24h·0.1MPa), 2.704×10⁵cm³/(m²·24h·0.1MPa) and 2.693×10⁵cm³/(m²·24h·0.1MPa). The arithmetic mean value of the three samples was 2.689×10⁵cm³/(m²·24h·0.1MPa).

Conclusion

Gas permeability is an important performance index of organosilicone film. In this paper, the carbon dioxide transmission of an organosilicon film was measured by differential pressure method. From the test results, the uniformity of the three samples is good, and the permeability of carbon dioxide in the sample is high. In terms of the test process, the equipment is easy to operate, and three samples can be tested in one time which improves the test efficiency.

Jinan Labthink Instruments Co., Ltd, is dedicated to providing customers with packaging testing solutions and helping the manufacturers to reach their goals of quality and safety assurance through improvement of packaging testing techniques and development of high-end packaging testing instruments. The newly introduced C series barrier testing systems adopting self-sensing technology revolutionarily improved the testing accuracy, efficiency and automation, realized the paradigm shift of packaging barrier testing instruments. For more information please visit www.labthink.com