Abstract: With the advancement of packaging technology, nitrogen-filled packaging has been widely used in food, medicine and other product packaging. Whether the nitrogen concentration in the package can be maintained is one of the key factors that determine the quality of the nitrogen-filled packaging. This article specifically analyzes the performance indexes that should be focused on flexible plastic packaging materials used for nitrogen-filled packaging, so as to provide a reference for enterprises to select packaging materials for nitrogen-filled packaging.
Keywords: nitrogen-filled packaging, flexible plastic packaging materials, nitrogen permeation, oxygen permeation, sealing performance, heat seal strength, flexibility
With the improvement of people's requirements for living standards, the types of food, drugs and other products are changing rapidly. The direction of product research and development tends to be less added, green, and pollution-free. The circulation area is becoming wider and wider. High requirements have been put forward to ensure that the products maintain good quality during the circulation process and shelf life.
Nitrogen-filled packaging is a packaging technology in which nitrogen replaces the gas in the packaging. Nitrogen as an inert gas can inhibit the reproduction of microorganisms and has no interaction with product components. Placing the product in a nitrogen atmosphere can reduce the oxygen concentration in contact with the product, and can inhibit the physiological activities of microorganisms, enzyme activities and fresh products. The breathing intensity can achieve the purpose of anti-virus, antiseptic and fresh-keeping. In addition, nitrogen-filled packaging also has the effect of preventing the product from being crushed, deformed, and broken, which can keep the product intact. However, in order to give full play to the above functions, the packaging materials used should have good performance, so that the nitrogen concentration inside the packaging is kept at a high level. To this end, this article specifically analyzes the performance indicators that nitrogen-filled packaging materials should focus on.
Figure 1 Nitrogen-filled packaged food
Nitrogen permeability
Nitrogen permeability refers to the amount of nitrogen permeating through a unit area of ​​material per unit time. The value of this index directly affects the speed of nitrogen penetration inside the package. If the nitrogen permeability of the packaging material used is high, the nitrogen inside the package If the loss is faster, the packaging is prone to deflated during the storage and shelf life of the product, so a low nitrogen permeability is the basic performance of nitrogen-filled packaging materials.
At present, the testing method of nitrogen permeability of packaging materials is mainly the differential pressure method, and the standard is based on GB / T 1038-2000 "Differential Pressure Method for Gas Permeability Test Methods of Plastic Films and Sheets".
Oxygen permeability
Oxygen permeability refers to the amount of oxygen permeating through a unit area of ​​packaging material per unit time. The level of this performance is closely related to the penetration of oxygen in the environment into the package during the storage process of nitrogen-filled packaging. The oxygen permeability of packaging materials is higher , The penetration rate of oxygen into the package is faster, so that the gas composition and content inside the package will change greatly in a short time, the nitrogen concentration decreases, the oxygen concentration increases, weakens or even loses the protection that the nitrogen-filled package should have Oxidation, anti-mildew and other effects. Therefore, the packaging material used as nitrogen-filled packaging should have a low oxygen permeability.
The testing methods for oxygen permeability of flexible plastic packaging materials are equal pressure method and differential pressure method. The standards are based on GB / T 19789-2005 "Coulometer Test Method for Oxygen Permeability Test of Plastic Film and Sheets of Packaging Materials" T 1038-2000 "Test Method for Gas Permeability of Plastic Films and Sheets Differential Pressure Method".
Heat seal strength
The heat seal strength refers to the force value required to destroy the heat seal portion of the packaging bag, and the index value reflects the seal fastness of the heat seal portion. There are many gases in the nitrogen-filled packaging, and the squeezing force generated on the heat-sealed part is large. The gas is easy to escape from the poor heat seal and even break the bag. Therefore, a good heat seal strength is necessary to ensure that the nitrogen-filled package does not leak and reduce the rate of bag breakage.
Mainly according to the standard QB / T 2358-1998 "Test method for heat sealing strength of plastic film packaging bags" to test the heat sealing strength of packaging bags.
Flexibility
In the process of product transportation and circulation, the packaging bag will inevitably be crushed and rubbed by external forces, and the surface of the bag body is prone to creases. If the flexibility of the package is poor, the defects generated in the creases are prone to air leakage under the impact of the gas inside the nitrogen-filled package, resulting in a reduction of the gas inside the package and a change in the content of the gas component. The test indicators of the flexibility of packaging materials are tensile strength and elongation at break (tested according to the standard GB / T 1040.3-2006 "Determination of plastic tensile properties Part 3: Test conditions for films and sheets"), and rub resistance ( According to American standard ASTM F392 test).
Sealing performance
The sealing performance test is whether the packaging is prone to air leakage. Good sealing performance requires that the surface of the packaging bag and the heat-sealed parts are free of defects that can cause air leakage in the packaging.
At present, the sealing performance of flexible plastic packaging bags is mainly verified by the negative pressure method test, and the standard is GB / T 15171-1994 "Test Method for Sealing Performance of Flexible Packaging Parts".
The above-mentioned nitrogen permeation, oxygen permeation, heat seal strength, flexibility, and sealing performance are all necessary to ensure the volume and concentration of nitrogen in the nitrogen-filled packaging, and to fully exert its anti-oxidation and anti-mildew quality assurance effect on the product. Performance indicators focused on. In addition, depending on the packaged product, the performance indicators of the materials that need attention are also different. For example, nitrogen-filled packaging materials for potato chips dry foods should also pay attention to their water vapor transmission rate, solvent residue, and total migration. Amount, heavy metal, potassium permanganate consumption, etc. Jinan Languang Electromechanical Technology Co., Ltd. is a high-tech enterprise specializing in packaging testing, R & D, production and packaging testing services. It can provide equipment and data support for quality control and screening of all-round performance of packaging materials, and understand related testing equipment and testing services. You can log in to view. The more you understand, the more you trust! Labthink looks forward to enhancing technical communication and cooperation with enterprises and institutions in the industry.
Food Grade Essential Oil,Cumin Oil,Garlic Oil,Black Pepper Oil
Ji'An ZhongXiang Natural Plants Co.,Ltd. , https://www.zxnaturaloils.com