Thin packaging film with high tensile property and preparation method thereof

Abstract

The invention relates to a packaging film and discloses a thin packaging film with a high tensile property and a preparation method thereof. The problem that the stretching ratio is greatly reduced after a conventional packaging film is thinned is solved in the invention. The thin packaging film is a co-extruded seven-layer composite film with a thickness of 10-12 microns; the seven-layer composite film comprises a first layer, a second layer, a third layer, a fourth layer, a fifth layer, a sixth layer and a seventh layer from one side to the other side with a cross section as a starting point; the seven film layers take metallocene linear low-density polyethylene as a matrix; maleic anhydride and tannin phenolic compounds are mixed into the second layer and the sixth layer so as to improve the binding force between the second and sixth layers and the film layers at the two corresponding sides and improve the toughness of the film layers, so change difference values of the two sides ofthe first and seventh layers located out of the second and sixth layers and the third, fourth and fifth layers located between the second and sixth layers in the stretching process are alleviated, and the layered fracture of the packaging film is delayed; and thus, the original stretching ratio and tension of the packaging film are maintained on the basis of thinning of the packaging film.

Description

technical field [0001] The invention relates to a packaging film, in particular to a thin packaging film with high tensile performance and a preparation method thereof. Background technique [0002] Plastic film flexible packaging is an existing packaging method, which uses a long strip of plastic packaging film to wrap and pack pre-packaged objects. Also due to its packaging method, the packaging film used for it is required to have good tensile properties and tensile strength, so as to ensure that the packaging film is taut and wraps the pre-packaged objects after packaging. [0003] Existing packaging films include multi-layer extruded metallocene polyethylene packaging films, which are widely used due to their advantages of environmental protection, non-toxicity and good toughness. For example, the product developed by our company, the Chinese patent "A High Tensile Film and Its Production Method" with the publication number CN109177400A, discloses a high tensile film, ...

AI Technical Summary

Problems solved by technology

However, as far as the above-mentioned packaging film is concerned, after the overall thickness is reduced according to the thickness ratio of its components, the difference in tensile properties between the layers increases, and the outer film layer deforms and breaks first during the re-stretching process, further deteriorating the tensile strength , the packaging film is broken, and the stretching ratio is greatly reduced, which cannot meet the demand. Therefore, a thinner and high-stretching packaging film that maintains the original packaging tension is needed.

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