Abstract: The barrier properties of different gases are one of the key test performance indicators for K-coated films. In this paper, the VAC-V2 differential pressure gas permeation instrument was used to test the barrier properties of K-coated film samples for oxygen and nitrogen, and the test principle, equipment parameters, application range and test procedure were introduced. K-coated films provide a reference for testing the gas barrier properties. Key words: oxygen permeation, nitrogen permeation, oxygen barrier performance, barrier properties, differential pressure gas permeation instrument, K-coated film, K film, PVDC coating film 1, meaning As a high barrier material, PVDC (polyethylene terephthalate) is often used to coat the surface of PE, BOPP, BOPET, PA and other films with poor barrier properties to improve the overall barrier properties of the film. The film formed after coating is simply referred to as a K film (ie, a K-coated film), and KPA, KPET, KOPP, KPE, and the like are common. Due to good barrier properties, K film is used in food packaging such as cakes, candies, biscuits, etc. in the form of a single layer film or a composite film. Due to the variety of packaging products and packaging forms, the barrier properties of K-film materials are not the same. For example, oxygen-sensitive foods and air-filled foods have high barrier properties against oxygen and nitrogen. In addition, gas molecular structure The difference also determines the permeability of different gases in the package. Therefore, testing the K film for different gas barrier properties can further verify whether the barrier properties meet the shelf life requirements of the packaged product. 2, test samples In this paper, a K-coated monolayer film was used as a test sample, and the oxygen permeation amount and nitrogen permeation amount were respectively tested. 3. Test basis At present, the test methods for oxygen permeability of packaging materials include pressure difference method and equal pressure method, and the nitrogen permeability test method can only use differential pressure method. Therefore, in this paper, the differential pressure method is used to test the barrier properties of oxygen and nitrogen, respectively. The test procedure is based on GB/T 1038-2000 "Phase Difference Method for Plastic Film and Sheet Gas Permeability Test Method". 4, test equipment In this test, the VAC-V2 differential pressure gas permeation instrument was used as the testing equipment. The equipment was independently developed and produced by Jinan Languang Electromechanical Technology Co., Ltd. 4.1 Principle of the test The differential pressure method is to achieve gas permeation from the high pressure side to the low pressure side by the pressure difference on both sides of the sample, and the pressure sensor is used to monitor the pressure change on the low pressure side. Firstly, the test chamber of the device is divided into upper and lower parts by using the clamped sample, and the test gas is filled into the upper chamber by a certain pressure, and the lower chamber is vacuumed to form a low pressure environment, and the test gas penetrates into the low pressure through the sample. The cavity, according to the pressure sensor, detects the change of the pressure of the low pressure chamber with the penetration time, and calculates the permeability parameter such as the gas permeation amount of the sample. Figure 1 VAC-V2 differential pressure gas permeation meter 4.2 Scope of application (1) This equipment is specially used for the test of gas permeability, permeability coefficient, solubility coefficient and diffusion coefficient of various film and sheet samples at various temperatures. The film type includes various plastic film, paper-plastic composite film, co-extruded film, aluminized film, aluminum foil, aluminum foil composite film and the like. The sheet material includes various sheet materials such as engineering plastics, rubber, and building materials, such as PP sheets, PVC sheets, and PVDC sheets. (2) The equipment can also be extended to aerospace materials, paper and paperboard, paint film, fiberglass cloth, fiberglass paper, cosmetic hose sheets, various rubber sheets and other materials for gas permeability testing. (3) This equipment is suitable for permeability testing of various gases such as oxygen, nitrogen, carbon dioxide, helium, air, etc. (4) This equipment can meet a variety of national and international standards, such as GB/T 1038, ISO 15105-1, ISO 2556, ASTM D1434, JIS K7126-1, YBB00082003 and so on. 4.3 Equipment parameters 5, the test process 5.1 Oxygen transmission test (1) Use a sampler to cut three specimens with a diameter of 97 mm from the surface of the sample. (2) Apply a layer of vacuum grease around the three test chambers of the device, place one piece of filter paper in the test area, paste the three pieces of sample on the three test chambers in turn, and gently press to remove the sample and test chamber. The bubbles between them close the cavity and tighten. Figure 2 loading process (3) The device is connected to the oxygen gas source, set the sample name, vacuum time, test temperature, humidity and other parameter information on the control software, click to start the test, open the vacuum pump, the equipment is tested according to the set parameters, and is tested. The test results are displayed after the end. 5.2 Test of nitrogen permeation The device is switched on to a nitrogen gas source, and the rest of the operation is the same as 5.1. 6, test results The oxygen permeation amount and nitrogen permeation amount of the sample were taken as the arithmetic mean of the test results of the three samples. The oxygen permeation amount of the K-coated film sample tested in this test was 7.935 cm 3 /(m 2 ?24h?0.1MPa) The nitrogen permeation amount was 0.653 cm 3 /(m 2 ?24h?0.1MPa). 7. Conclusion The higher barrier properties are key properties of K-coated films that distinguish them from ordinary films. Depending on the specific application, oxygen permeation and nitrogen permeation are key performance indicators for K-coated films. In this paper, the barrier properties of K-coated film samples for oxygen and nitrogen were tested by the principle of differential pressure method. The nitrogen permeation of the sample was significantly lower than the oxygen permeation, which is related to the molecular diameter of the gas. The test process is simple, the result is highly accurate and intelligent, and the equipment is easy to operate. Jinan Languang Electromechanical Technology Co., Ltd. is a high-tech enterprise specializing in R&D, production and packaging testing services for packaging inspection equipment. The VAC-V2 differential pressure gas permeation instrument used in this paper is one of many independent research and development equipments. The equipment can also be used for testing the gas permeability of carbon dioxide, helium, air, sulfur hexafluoride and the like. In addition to gas permeation, Labthink's existing equipment can also test the water vapor transmission rate, tensile properties, puncture strength, tear strength, impact strength, friction coefficient, heat seal performance, thickness of K-coated film. Performance indicators such as total migration and solvent residue. The more you understand, the more you trust! Labthink is looking forward to enhancing technical communication and cooperation with enterprises and institutions in the industry. Fresh Carrot,Red Carrot,Bulk Fresh Carrot,Fresh Sweet Carrot Jining Sunagro Trade Co., Ltd. , https://www.sunagro-food.com
The molecular structure of carotene is equivalent to 2 molecules of vitamin A. After entering the body, it passes through enzyme action in liver and small intestinal mucosa, of which 50% becomes vitamin A, which has the effect of reinforcing liver and improving eyesight and can treat night blindness.As a kind of "filling material" in the intestinal tract, it can strengthen the intestinal peristalsis, thereby benefiting the diaphragm and preventing cancer.So the carrot is a germplasm crisp taste, rich nutrition of vegetables, known as "little ginseng", by the way, we also provide potatoes, carrots, cabbage, red star apple, fresh red Fuji, crown pear fresh fruit, fresh sweet pears, fresh broccoli, eggplant, fresh new potatoes, Garlic, garlic, Ginger, welcome to order.
