Test method for overall oxygen resistance of flexible plastic packaging bags

Abstract: oxygen resistance performance is an important performance related to the quality of soft plastic packaging bag and an important basis for selecting packaging materials In this paper, the aluminum plastic composite film packaging bag for food packaging is used as the test sample, and the ox2 / 230 oxygen permeability test system is used The oxygen permeability of the whole sample is tested, and the test principle, test process, equipment parameters and application scope are introduced, which provides reference for the enterprise to test the oxygen resistance performance of the whole soft plastic packaging bag Key words: oxygen resistance, oxygen transmission, oxygen transmission test system, soft plastic packaging bag, food packaging, aluminum plastic composite material 1 The meaning of oxygen resistance is expressed by oxygen transmission The high oxygen transmission of soft plastic packaging bag indicates the low oxygen resistance On the contrary, the low oxygen transmission means the high oxygen resistance At present, the samples for the test of oxygen resistance of packaging materials are mainly divided into thin films according to their forms/ The soft plastic packaging bag is usually cut into thin film form for testing, and the oxygen permeability obtained is the oxygen volume of the packaging material per unit time unit area, which is convenient for the research, comparison and quality control of the material's oxygen resistance performance If the overall oxygen permeability of the packaging bag is to be obtained, the membrane test value shall be multiplied by the surface area of the packaging bag, which will expand The error of the results, especially for the irregular shape bags, such as self-supporting bags, folding bags, suction mouth bags, etc., is greater because the area of the bags is not easy to calculate In addition, for the packaging materials with creases, pinholes and rubbing resistance on the surface, due to the existence of creases and other defects, the oxygen permeability of different parts of the packaging bag is different, and the overall oxygen resistance of the packaging calculated by the oxygen permeability of the material is not accurate Therefore, in order to evaluate the overall oxygen resistance of the soft plastic packaging bag, it is more important to directly test its overall oxygen transmission 2 The testing methods based on the oxygen permeability are mainly divided into two kinds: the isobaric method (coulometric method) and the differential pressure method At present, the method standard for testing the oxygen resistance performance of containers and packages published in China is GB / T 31354-2014 testing methods for oxygen permeability of packages and containers coulometric method This paper tests according to this standard 3 The test sample used in this paper is aluminum plastic composite film packaging bag for food packaging 4 In this paper, ox2 / 230 oxygen transmittance test system is used as the test equipment, which is independently developed and produced by Jinan Languang Electromechanical Technology Co., Ltd Figure 1 ox2 / 230 oxygen transmittance test system 4.1 test principle Coulometer method is a quantitative test method for the oxygen penetrating the sample by using coulometer In this method, the concentration difference is the power of oxygen penetrating the sample The specific process is that the pressure on both sides of the sample is kept equal during the test One side of the sample uses high-purity nitrogen as carrier gas and the other side uses high-purity oxygen After the oxygen penetrates the nitrogen side of the sample, it is carried to Coulomb by nitrogen Through the analysis, the oxygen permeability of the sample can be obtained For packages and containers, the outside of the sample is high-purity nitrogen and the inside is high-purity oxygen 4.2 equipment parameters: the test range of container type sample is 0.0001 ~ 60cm 3 / (PKG · d), the resolution is 0.00001 cm3 / (PKG · d); the test range of thin film type sample is 0.01 ~ 6500 cm3 / (M 2 · d), the resolution is 0.001 cm3 / (M2 · d); three identical or different samples can be tested at the same time, the system Zui can support parallel connection of 10 instruments, and establish 30 System for simultaneous test of samples; test temperature control range 15 ~ 55 ℃, temperature control accuracy ± 0.1 ℃; test humidity control range 0% RH, 35% RH ~ 90% RH, humidity control accuracy ± 1% RH ; wide range and high precision temperature and humidity control range, both sides of the sample can be humidified to realize the test of the sample under different temperature and humidity conditions; global link's first pressure compensation technology ensures the high precision and repeatability of the test results; it can be combined with the water vapor transmission test system to form a hybrid test system, which is controlled by a computer to realize the oxygen and water vapor transmission Test at the same time; support Lystem TM laboratory data sharing system, and uniformly manage test results and test reports 4.3 scope of application (1) This equipment is applicable to the test of oxygen permeability of containers, films, sheets and other types of samples, including bottles, bags, cans, boxes and barrels made of plastic, metal, rubber, paper, paper plastic composite, glass and other materials, such as Coke bottles, peanut oil barrels, Tetra Pak packaging, real empty packaging bags, metal three cans, plastic cosmetics packaging, toothpaste hoses, jelly cups, yogurt cups Film type includes all kinds of plastic cover film, plastic composite film, paper plastic composite film, coextrusion film, aluminum coating film, aluminum foil, aluminum plastic composite film and other film materials; sheet type includes all kinds of engineering plastics, rubber, building materials and other sheet materials, such as PP sheet, PVC sheet, PVDC sheet, etc (2) Applicable standards: GB / T 31354, ASTM f1307, ISO 15105-2, GB / T 19789, ASTM d3985, ASTM f2622, ASTM f1927, JIS k7126-2, ybb00082003 and other national and international standards 5 During the test, 5.1 sealing the sample, cut off one corner of one edge of the sample, insert the air inlet and outlet holes of the special sample holder of the container into the sample from the cutting edge, and then seal the sample on the tray with quick fix adhesive Fig 2 sample sealing Fig 5.2 sample loading clamp the sealed sample holder on the equipment, and seal and bind the sample and tray holder with the sealing bag 5.3 test: set the sample name, test temperature, test humidity, test mode and other parameter information, and click the test option to start the test Start the air source and adjust the carrier gas flow and humidity 5.4 end of test after the test, the equipment will automatically display the test value of oxygen transmission of the sample 6 Results in this test, the arithmetic mean of the test values of the two samples was taken as the oxygen permeability of the aluminum plastic composite film for food packaging, and the result was 0.2346 cm 3 / (PKG · 24h) 7 Conclusion good oxygen blocking performance is one of the key performance indexes of food packaging In this paper, the principle of equal pressure method is used to test the overall oxygen permeability of an aluminum plastic composite film packaging bag for food packaging From the perspective of the test process, the operation is simple, the equipment is highly automated, the test precision is high, and the test results can accurately reflect the overall oxygen blocking performance of the packaging bag For aluminum-plastic composite film packaging bags, in addition to the oxygen resistance performance, the heat sealing strength, sealing performance and rubbing resistance of the packaging are also important factors that determine the amount of oxygen penetrating into the packaging in the environment The corresponding detection equipment are intelligent electronic tensile testing machine, sealing tester and rubbing tester The more you understand, the more you trust! 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