The carbon dioxide gas permeability test mainly refers to the detection of the carbon dioxide gas penetration performance of packaging materials such as films, composite films, plastic sheets, etc., so as to evaluate the gas barrier performance of materials. Generally speaking, the food industry has more requirements for the carbon dioxide gas barrier performance of packaging materials, because carbon dioxide gas is commonly used in the packaging preservation process to replace oxygen to ensure the quality and taste of the products in the packaging. Therefore, the carbon dioxide gas permeability test of packaging materials is one of the more important testing items.
Carbon dioxide gas permeability tester is a professional laboratory instrument used to detect the gas permeability performance of flexible plastic packaging materials, and it is a gas permeability tester based on the principle of differential pressure test. The test standard can generally refer to the "GB T 1038-2000 Plastic Film and Flake Gas Permeability Test Method Differential Pressure Method". Like the plastic wrap products commonly used in our lives, there are strict requirements for its quality, and the "GB T 10457-2021 General Principles for the Quality of Plastic Self-adhesive Cling Film for Food" in the "GB T 10457-2021 General Principles for the Quality of Food Plastic Self-adhesive Cling Film" is also specified to be tested in accordance with the GB T 1038 standard. Below, we introduce the test principle and experimental process of the carbon dioxide gas permeability tester in combination with the differential pressure gas permeability tester on the market.
Approximate experimental process of carbon dioxide gas transmission rate tester:
1) Use a special sampler to cut 3 pieces of 97 mm diameter specimen from the sample surface. (2) Place the sample in a dryer in the 23 2 environment and adjust the state for 48 h. (3) After the sample is taken out, the thickness of the sample is measured, and the average value of the measurement is the thickness of the sample. (4) Apply a layer of vacuum grease around the test chamber, place a piece of filter paper in the test area, and then clamp the specimen to the test chamber and clamp it with a clamping structure. (5) Connect the carbon dioxide gas source, set the sample name, thickness, test humidity, test temperature, test mode and other parameter information, turn on the vacuum pump, click the test option, and the test starts. After entering the test state, turn off the vacuum pump. At the end of the test, the machine automatically displays the test values of the three specimens. 
Introduction to the test principle of carbon dioxide gas permeability tester: the differential pressure method refers to the test method of maintaining a certain pressure difference between the two sides of the sample during the test process, and calculating the gas permeability of the sample according to the change of pressure on the low pressure side. The realization process is that, after the sample is clamped to the test chamber of the equipment, the test chamber is divided into two test chambers, the upper and lower test chambers, the two test chambers are vacuumed, and then the upper chamber is filled with the test gas of a certain pressure, so that a certain pressure difference is formed on both sides of the sample, the test gas penetrates into the lower chamber through the sample through the upper chamber under the action of pressure difference, and the parameters such as gas permeability and permeability coefficient of the sample are calculated through the real-time monitoring of the change of the pressure of the lower chamber with time.