The indicators of food packaging inspection and control mainly include: barrier performance, physical and mechanical properties, hygienic performance, thickness, solvent residue, retort resistance, sealing performance, cap torque, headspace analysis, printing quality, sealing performance, etc. 1. Barrier performance of food packaging materials The main cause of food deterioration is the growth and reproduction of microorganisms. Oxygen and water vapor in the environment can affect the quality of food through packaging materials. Therefore, the oxygen and water vapor transmission rates of packaging materials are closely related to the shelf life. Another major cause of food spoilage is the oxidative deterioration of ingredients such as fats and oils. Therefore, food packaging should be required to have a good barrier effect. Oxygen permeability testing standards are: ASTMD3985, ASTMF2622, ASTMF1927, ASTMF1307, ISO15105-2, GB/T19789. The moisture permeability test standard is: ISO15106-3, DIN53122-2, GB/T21529. 2. Physical and mechanical properties of food packaging materials 1. Tensile strength and elongation at break The most basic function of food packaging is to be used as a container for transporting food, and the material is required to have a certain strength to prevent accidental rupture. The tensile strength and elongation at break of packaging materials are the most basic performance requirements. We can perform a constant tension test using a universal testing machine for tensile strength and elongation at break. The commonly used test standard is GB/T13022. 2. Thickness The thickness and width of packaging materials must meet certain requirements. The thickness of a film or sheet can be measured with a precision thickness gauge over a standard pressure range. The test standard is ASTMD374, ISO534, GB/T6672. 3. Heat sealing performance Heat sealing performance directly affects the overall physical properties of food packaging. Heat-seal packaging materials by selecting appropriate heat-sealing parameters (temperature, pressure, time) to obtain optimum heat-sealing strength. The effect of heat sealing The seal strength of the seal can be tested using a universal material testing machine. The test standard is ASTMF2029, QB/T2358. 4. Coefficient of friction Friction coefficient is a physical quantity used to characterize the resistance generated when soft plastic packaging materials are in contact with other materials (such as packaging machinery) and the relative movement during use. If the coefficient of friction of the packaging material is too large or too small, it will have an adverse effect on the production process. For example, if the coefficient of friction is too large and the packaging material is crumpled, a large pulling force is required to rotate the reel to hold the bag, which not only increases. Large energy consumption, reduced production efficiency, and may even cause stretching deformation of the packaging material, which affects its barrier properties and physical and mechanical properties, such as impact resistance and puncture resistance; when the coefficient of friction is too small, it is easy to cause the material to be used . There are issues like slipping, drifting, stack instability and edge errors. Therefore, controlling the coefficient of friction of flexible plastic packaging films is of great significance for improving the convenience of use within a suitable range. The commonly used test standard is GB/T10006. 5. Tear measurement The test of tear strength actually measures the energy required for tear propagation. The main measurement methods are the trousers method and the Elemendorf tear method, with the Elemendorf tear method being the first choice for specimens of constant radius. . For consumers, the tear resistance of a material is a major indicator of how easy a package is to open. Commonly used testing standards are ASTMD1922, ISO6383/2. 6. Printed Surface Roughness Clear patterns and logos are printed on the finished package. However, we also found that printing on certain materials (especially paper or paper laminates) was blurry, some related to the ink quality and color registration process, and a large part related to the roughness of the printing surface. Since the generally printed ink layer is only tens of microns thick, if the surface roughness of the printing is too large, the printed ink layer will be buried in the deep layer of the material, so that the thickness of the ink layer on the surface will be uneven and produce hair. white phenomenon. We should conduct a roughness test on the printing surface, measure the surface roughness by simulating the conditions of the printing press, and check the influence of the smoothness of the material on the printability from a microscopic point of view. The ink layer can be adjusted 2 to 2.5 times depending on the roughness result. thickness of. Commonly used testing standards are ISO8791/4, TAPPIT555. 7. Ink friction Food packaging consumes a lot of ink during the printing process. Sometimes when we come into contact with food packaging, we will encounter ink stains or ink peeling off, which will seriously affect consumers’ willingness to buy. This entails testing the ink’s rub resistance by rubbing the two materials against each other at a set speed using a standard ballast to see how fast the printed ink is. According to different conditions of actual use, it can be divided into dry rubbing, wet rubbing, wet transfer, wet smearing and thermal rubbing. 3. Sealing of food packaging materials and modified atmosphere packaging The sealing performance refers to the reliability of packaging seals. This testing ensures the integrity of the entire product packaging seal and prevents leaks, contamination, deterioration and other issues due to poor product seal performance. There are two test methods: positive pressure and negative pressure. More and more packages are using modified atmosphere packaging to extend shelf life, such as milk powder, coffee, potato chips and cheese packaged in nitrogen and carbon dioxide. In order to test the actual inflation effect, a headspace analyzer is required to analyze the actual gas composition in the package. Related instruments: oxygen permeability meter, moisture permeability meter, heat sealing machine, thickness meter, peel strength meter, general material testing machine, friction coefficient meter, tear meter, peel tester, printing surface roughness meter, leak detector, Seal tester, headspace analyzer. The above is what are the indicators for the inspection and control of “packaging bags” food packaging? “‘s entire content.
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