Verification of oxygen barrier property of PE film by vac-v2 gas permeation tester

Abstract: fresh keeping film is a kind of plastic packaging product used to keep fresh food It can be used to heat food in microwave oven and store food in refrigerator, so it is required to have high oxygen permeability This paper uses Labthink blue light vac-v2 differential pressure gas permeameter to test the oxygen barrier performance of PE fresh-keeping film to the outside world, and details the test process, test principle, equipment parameters, etc., which can be used as a reference for enterprises in selecting oxygen permeability test equipment and test methods Key words: PE preservative film, oxygen permeability, oxygen permeability, barrier performance, differential pressure gas permeameter 1 The current preservative film is a plastic packaging product, usually ethylene as the master material through polymerization It is mainly used in microwave food heating, refrigerator food preservation, fresh and cooked food packaging and other occasions It is widely used in family life, supermarket, hotel and industrial food packaging According to the different materials and plasticizers, the fresh-keeping film can be divided into the following types, which are suitable for different occasions * polyethylene, referred to as PE, is mainly used for food packaging, such as fruits, vegetables and semi-finished cooked food sold in supermarkets It is characterized by a wide range of use and can be packaged with grease food It can be heated in a microwave oven, but the temperature does not exceed 110 ℃ The second is PVC, which can also be used for food packaging, but it has certain harm to human safety; the third is PVDC, which is mainly used for packaging some cooked food, ham and other products Among the three kinds of fresh-keeping films, PE and PVDC are safe for human body and can be used safely, while PVC fresh-keeping film is harmful to human body because it contains carcinogens Therefore, in the purchase of preservative film, PE preservative film In general, the higher the oxygen permeability (i.e the higher the barrier) is, the better the fresh-keeping effect is Fig 1 PE fresh keeping film 2 Test standard domestic test methods for oxygen permeability of soft plastic packaging materials are mainly differential pressure and coulometric method (i.e isobaric method) The reference method standards are respectively GB / T 1038 test method for gas permeability of plastic film and sheet pressure method and GB / T 19789 test method for oxidation permeability of plastic film and sheet of packaging materials Coulometer test method In this paper, the principle of the differential pressure method for testing, the reference standard is GB / T 1038 3 The test sample is PE fresh keeping film produced by a factory 4 Test equipment: vac-v2 pressure difference gas permeameter independently developed and designed by Jinan Languang Electromechanical Technology Co., Ltd Fig 2 test principle of vac-v2 pressure difference gas permeameter First, vacuum the low-pressure chamber (lower chamber), and then vacuum the whole system; when the specified vacuum degree is reached, close the lower chamber for testing, fill the high-pressure chamber (upper chamber) with a certain pressure of test gas, and ensure that a constant pressure difference (adjustable) is formed on both sides of the sample; in this way, the gas will permeate from the high-pressure side to the low-pressure side under the effect of the pressure gradient, and pass By monitoring the pressure in the low pressure side, the barrier parameters of the tested sample can be obtained 4.2 scope of application (1) this equipment is applicable to the test of the package gas transmissivity of plastic film, sheet, paper, paperboard and their composite materials, cosmetic hose sheet, various rubber sheet, including oxygen, air, nitrogen, carbon dioxide and other gases Film type: gas permeability test of various plastic film, paper plastic composite film, aluminum coating film, aluminum foil, aluminum foil composite film and other film-like materials Sheet materials: gas permeability test of various engineering plastics, rubber, building materials and other sheet materials, such as PP sheet, PVC sheet, PVDC sheet, etc (2) this equipment is suitable for the transmittance test of various gases, such as oxygen, carbon dioxide, nitrogen, air, helium, etc and the barrier performance test of various films for flammable and explosive gases (3) the equipment can meet a number of national and international standards, such as ISO 15105-1, ISO 2556, GB / T 1038, ASTM d1434, JIS k7126-1, YBB 00082003 4.3 test range of equipment parameters: 0.05 ~ 50000 cm 3 / M 2 · 24h · 0.1MPa Sample number: 3 pieces (data are independent) test temperature range: 5 ℃ ~ 95 ℃, temperature control accuracy ± 0.1 ℃; test humidity range: 0% RH, 2% RH ~ 98.5% RH, 100% RH, temperature control accuracy ± 1% RH Support the test of toxic test gas and flammable and explosive gas (need to be modified) Data fitting can be carried out at any temperature, and test results under extreme conditions can be easily obtained Support Lystem TM laboratory data sharing system, manage test results and test reports in a unified way 5 Test process (1) cut three samples with a size of Φ 97 mm with a sampler (2) install three pieces of samples on three test chambers of the equipment (3) set the sample name, sample thickness, test temperature, test humidity and other parameters (4) start the vacuum pump (5) click the "start test" option to start the test, and the instrument will automatically calculate and display the test results 6 The results showed that the permeability of oxygen was 49.3704 cm 3 / M 2 · 24 h · 0.1 MPa, 48.1021 cm 3 / m2 · 24 h · 0.1 MPa, 48.2883 cm 3 / m2 · 24 h · 0.1 MPa 7 Conclusion vac-v2 pressure difference gas permeameter is a kind of oxygen permeameter which is used for membrane and sheet It has the advantages of simple operation, high accuracy and good repeatability, and can reflect the oxygen barrier performance of PE fresh-keeping film Labthink Languang, as the leader of packaging testing equipment R & D and manufacturing industry, provides professional packaging testing equipment and testing services for global customers To learn about the relevant testing equipment, you can log in Jinan Languang company to check or call for consultation Jinan Languang Electromechanical Technology Co., Ltd is willing to take this opportunity to enhance technical exchanges and cooperation with enterprises and institutions in the industry.