Abstract: Plastic wrap is a plastic packaging product used by people to keep fresh food. It can be heated with microwave food and stored in the refrigerator to the refrigerator. Therefore, it is required to have high oxygen permeability. In this paper, Labthink VAC-V2 Gas Permeability Testing Instrument PE cling film outside oxygen barrier properties, and detailed test procedures and test principle content, and other equipment parameters, companies select the desired oxygen permeation performance test equipment and test The method can be referred to. Key words: PE cling film, oxygen permeability, oxygen transmission rate, barrier property, differential pressure gas permeation instrument 1 , the status quo Is a plastic wrap packaging products, usually ethylene masterbatch formed by polymerization reaction, is mainly used for microwave heating of food, food preservation refrigerator, fresh and cooked food packaging applications, family life, supermarket stores, hotels and Industrial production of food packaging has a wide range of applications. Depending on the materials used and the addition of plasticizers, cling film is mainly divided into the following types, which are suitable for different occasions. * Kind of polyethylene, referred to as PE , this material is mainly used for food packaging, such as fruit, vegetables and semi-finished products sold in supermarkets. It is characterized by a wide range of can be packaged fat food, can be heated in the microwave, but the temperature is not More than 110 degrees Celsius. The second type is polyvinyl chloride, referred to as PVC . This material can also be used for food packaging, but it has certain harm to human body safety; The third type is polyvinylidene chloride, referred to as PVDC , which is mainly used for the packaging of some cooked food, ham and Other Products. Among the three kinds of plastic wrap, the cling film of PE and PVDC is safe for the human body and can be used with confidence. The PVC wrap film is harmful to the human body because it contains carcinogens. Therefore, PE wrap is preferred when purchasing cling film. PE cling film on the merits of the oxygen barrier properties related to the degree of preservation of food, in general, the greater the oxygen transmission rate (i.e., higher barrier property) of fresh food preservation effect is better. Figure 1 PE cling film 2 , testing standards The domestic test methods for oxygen transmission rate of soft plastic packaging materials are mainly pressure difference and Faulun method (ie, equal pressure method). The reference method standards are GB/T 1038 "Plastic film and sheet gas permeability test". Method Differential Pressure Method and GB/T 19789 "Packaging Material Plastic Film and Sheet Oxidation Permeability Test Coulomb Test Method". This paper uses the differential pressure method as the principle to test, the reference standard is GB/T 1038 . 3 , test samples PE cling film produced by a factory . 4 , test equipment Jinan Languang Electromechanical Technology Co., Ltd. independently developed the VAC-V2 differential pressure gas permeation instrument . Figure 2 VAC-V2 differential pressure gas permeation meter 4.1 Test principle The VAC-V2 adopts the differential pressure test principle, and the pre-treated sample is placed between the upper and lower test chambers and clamped. First, vacuum treatment is performed on the low pressure chamber (lower chamber), and then the whole system is vacuumed; when the specified degree of vacuum is reached, the lower chamber of the test is closed, and the test gas of a certain pressure is filled into the high pressure chamber (upper chamber), and the test gas is ensured A constant pressure difference (adjustable) is formed on both sides of the sample; thus, the gas will permeate from the high pressure side to the low pressure side under the action of the pressure difference gradient, and the internal pressure of the low pressure side is monitored and processed, thereby obtaining the test sample. Various barrier parameters. 4.2 Scope of application (1) This equipment is suitable for packaging gas permeability test of plastic film, sheet, paper, cardboard and composite materials, cosmetic hose sheet, various rubber sheets, etc., including oxygen, air, nitrogen, carbon dioxide and other gases. . (2) This equipment is suitable for the permeability test of various gases, such as oxygen, carbon dioxide, nitrogen, air, helium, etc., as well as the barrier properties of various films for flammable and explosive gases. (3) This 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 Equipment parameters 5 , the test process (1) Cut 3 pieces of the sample of size Φ97 mm with a sampler . (2) The three samples were clamped in a test chamber 3 devices. (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, the test starts, and the instrument automatically calculates and displays the test results. 6 , test results The oxygen transmission rates tested in this paper are: 49.3704 cm 3 /m 2 ·24h·0.1MPa , 48.1021 cm 3 /m 2 ·24h·0.1MPa , 48.2883 cm 3 /m 2 ·24h·0.1MPa . 7 , conclusion VAC-V2 differential pressure gas permeation instrument is a professional oxygen permeability test instrument for film and sheet. It has simple operation, high test accuracy and good repeatability. It can reflect the oxygen barrier performance of PE plastic wrap. As a leader in the development and manufacturing of packaging inspection equipment, Labthink provides professional, high-end packaging inspection equipment and testing services to customers around the world. To find out about its related testing equipment, you can visit Jinan Languang Company or call us . Jinan Languang Electromechanical Technology Co., Ltd. is willing to enhance technical exchanges and cooperation with enterprises and institutions in the industry. Sulfate Series,Feed Grade Magnesium Sulfate,High Purity Medicine Grade,Magnesium Sulfate Dried Powder LIANYUNGANGLONGTAIWEI FOOD INGREDIENTS CO.,LTD. , https://www.longtaiweifood.com
