There are many varieties of logistics stretch film, this you should have

There are many varieties of logistics stretch film, this you should have! Stretch film is the main packaging material in the logistics industry, which brings a lot of convenience to the logistics industry. Stretch film has special requirements for product protection, promotion functions, adaptability to packaging machinery and other applications. The protective function of packaging materials for commodities is the most important and basic function. It is no exaggeration to say that if the stretch film does not have a reliable protective function for the packaged commodities, then it will lose its use value as a packaging material. The protective function of stretch film for commodities is various. Different commodities and different packaging forms have different emphasis on the protection function of stretch film. There are many varieties of logistics stretched films. In the use of many stretched films, there are often situations of mutual penetration and mutual substitution, but the characteristics of various stretched films themselves cannot be ignored. Therefore, the correct selection and application of logistics packaging film is not easy. This requires personnel in the packaging material industry to understand some of the corresponding basic functions of the stretch film. Reliable mechanical protection includes preventing the leakage of goods in the package or the destruction and pollution of goods by foreign substances entering the package. The performance indicators that directly reflect the mechanical protection function of the stretched film are mainly the mechanical strength of the film, such as tensile strength, tear strength, falling impact strength (drop impact) and puncture resistance. Good welding strength is also a necessary condition for packaging bags to reliably protect products. If the welding seam strength is insufficient, the welding seam will become the Achilles heel of the packaging bag, and the plastic bag will lose its protective effect on the goods due to the rupture of the weld seam. Ordinary polypropylene biaxially oriented film has good mechanical strength, but because of its poor welding performance, biaxially oriented polypropylene single film is generally not used for bag making. The welding performance of the stretched film is usually expressed by the weld strength, that is, N/15mm. The higher the weld strength, the better the welding performance. Among other functions for product protection, barrier properties and shading properties are most often considered. Barrier performance refers to the performance of the stretched film to prevent oxygen, carbon dioxide, nitrogen and other gases, aromas, water vapor and other substances from penetrating. When the scope is not clear, it generally refers to the barrier to non-polar gases such as oxygen, carbon dioxide and nitrogen. When we select stretch film, we must first grasp the characteristics of the product and its basic requirements for packaging, and at the same time, we must have a clearer understanding of the basic performance and main features of stretch film, especially the commonly used stretch film. Only in this way can the ideal stretch film be selected. The surface of the stretched film should be flat and smooth, with no wrinkles or only a few live folds, no obvious unevenness, black spots, impurities, crystal points and rigid blocks, no stripes, spots, violent tendons, etc., no bubbles, For pinholes and cracks, the aluminized layer of the aluminized film should be uniform, and no obvious bright stripes, yin and yang surfaces, etc. are allowed. In addition, the surface of the film is required to be clean and free of dust, oil, etc.