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　　The protection function of packaging materials is that a product must go through loading and unloading, transportation, storage, display and other links from the end of packaging to the arrival of customers. In each link, there are many factors that cause packaging damage. Packaging protection refers to the need to avoid the loss of product quality and quantity caused by these damages in the logistics process, so as to ensure the smooth completion of product value and application value.

　　Packaging material is the material basis of product packaging and the direct carrier of packaging function. To end the protective function of packaging, it is necessary to select a suitable one. The packaging materials and containers made of it should not only bear various mechanical forces such as static pressure, impact and vibration in the process of circulation, but also prevent the oxidation and corrosion of the contents by external substances and avoid the entry of the contents themselves.

　　Packaging materials are involved in completing many of these convenient functions. For example, convenient opening and use require packaging materials to have appropriate mechanical functions. Convenient stacking and loading and unloading require packaging materials to have strong tensile strength and compressive strength. Convenient processing includes packaging materials, which can be recovered, reused and easily decomposed. The research of green packaging materials is to meet this function

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