Test method for carbon dioxide permeability of nano preservative film

Abstract: the permeability of carbon dioxide is one of the important performance indexes of fresh keeping film materials In this paper, the permeability of carbon dioxide of the nano film was measured by using vac-vbs pressure difference gas permeameter, and the test principle, equipment parameters, application scope, test process and other contents were introduced to provide reference for the test and research of carbon dioxide permeability of plastic film materials Key words: carbon dioxide transmission, carbon dioxide transmission performance, differential pressure gas permeameter, nano preservative film 1, meaning nano preservative film refers to the film material synthesized, modified and added on the nano scale, which can be used for the preservation of fruits, vegetables, meat products, fresh milk, beer, cooked food and other food Compared with common fresh-keeping materials, nano fresh-keeping film has obvious advantages in heat resistance, antibacterial, antiseptic and other aspects According to the different characteristics of the packaged food, the fresh-keeping film should have the corresponding performance parameters Among them, the gas permeability (barrier) performance is an important reference index to determine whether the nano preservative film can produce a good preservative effect on the packaged food For example, when packaging fresh fruits and vegetables, the preservative film should have appropriate oxygen and carbon dioxide permeability to adapt to and limit the respiration of fruits and vegetables In this paper, the carbon dioxide transmission of nano film was tested 2 Nano preservative film of test sample 3 At present, the test method of carbon dioxide transmission mainly adopts the principle of differential pressure method, and the test process is based on the standard GB / T 1038-2000 test method of gas transmission of plastic film and sheet - differential pressure method 4 In this test, vac-vbs differential pressure gas permeation instrument is used to test the nano fresh keeping film samples The equipment is independently developed and produced by Jinan Languang Electromechanical Technology Co., Ltd Fig 1 4.1 test principle of vac-vbs pressure difference gas permeameter The principle of pressure difference method is to maintain a certain pressure difference on both sides of the sample during the test After the sample is clamped into the test chamber of the equipment, the test chamber is divided into upper and lower chambers The upper chamber is filled with a certain pressure of test gas carbon dioxide, and the lower chamber is vacuumized to form a low-pressure environment, so that a certain pressure difference is formed on both sides of the sample In the test, driven by the pressure difference, the carbon dioxide in the upper chamber penetrates into the lower chamber slowly from the upper chamber through the sample, resulting in the increase of the pressure in the lower chamber When the stable penetration is achieved, the pressure in the lower chamber has a linear relationship with the penetration time According to this linear relationship, the carbon dioxide transmittance of the sample can be calculated 4.2 scope of application (1) this equipment is applicable to the gas permeability test of various films and sheets Film type includes various plastic film, paper plastic composite film, coextrusion film, aluminum coating film, aluminum foil, aluminum foil composite film and other film-like materials; sheet type includes various engineering plastics, rubber, building materials and other sheet materials, such as PP sheet, PVC sheet, PVDC sheet (2) The equipment can also be extended to the air permeability test of aerospace materials, paper and cardboard, paint film, fiberglass cloth, fiberglass paper, cosmetic hose sheet, various rubber sheets and other materials (3) This equipment is suitable for the transmittance test of various gases, such as oxygen, carbon dioxide, nitrogen, helium, air, etc (4) This equipment meets many national and international standards, such as iso15105-1, iso2556, GB / T 1038, ASTM d1434, JIS k7126-1, ybb00082003 4.3 test range of equipment parameters is 0.1 ~ 100, 000cm 3 / (M 2 · 24h · 0.1MPa); can complete the test of three samples at the same time, the test result is the average value of the test results of three samples; the temperature range of the sample is 15 ~ 55 ℃, the temperature control accuracy is ± 0.1 ℃; provide standard membrane for rapid calibration to ensure the accuracy and universality of the test data; support Lystem TM Laboratory data sharing system, unified management of test results and test reports 5 During the experiment (1) three samples with a diameter of 97 mm were cut from the surface of the samples (2) Apply a layer of vacuum grease around the three test chambers of the equipment, respectively place a piece of filter paper in the test area, paste three samples on the test chamber, press gently to remove the air bubble between the test chamber and the sample, and then clamp with a clamping device (3) Connect the carbon dioxide gas source, set the sample name, test temperature, humidity, test mode, vacuum pumping time and other parameter information on the equipment control software, click the test option, open the vacuum pump, and the test starts (4) The equipment is tested automatically according to the set parameters After the test, the test results will be displayed 6 The results showed that the carbon dioxide permeability of the samples was 3.9046 × 104cm 3 / (m 2.24h.0.1mpa) 7 Conclusion the permeability of carbon dioxide through nano film is an important factor affecting the fresh-keeping effect of fresh fruits and vegetables High carbon dioxide permeability is conducive to delaying the aging of fruits and vegetables, maintaining the nutrition and color, and ensuring the good storage quality of fruits and vegetables In this paper, the permeability of carbon dioxide in the samples of nano fresh keeping film is measured by the differential pressure method The test process is simple, the equipment is easy to operate, the degree of intelligence is high, the test results are accurate and reliable, and the test efficiency is high In addition to carbon dioxide, the principle equipment can also be used to test the permeability of oxygen, nitrogen, air, sulfur hexafluoride, helium and other gases Jinan Languang mechanical and Electrical Technology Co., Ltd is a high-tech enterprise specializing in the research and development of packaging testing equipment, production and packaging testing services The existing equipment can almost test the performance indicators of soft plastic packaging materials More understanding, more trust, Labthink Languang expects to enhance technical communication and cooperation with enterprises and institutions in the industry!