Biaxially-oriented polypropylene anti-mist film with five-layer coextrusion and manufacturing method thereof

Abstract

The invention relates to a biaxially-oriented polypropylene anti-mist film with five-layer coextrusion and a manufacturing method thereof. The anti-mist film comprises an upper layer, an upper sublayer, a middle layer, a lower sublayer and a lower layer and is in a five-layer structure, wherein the upper layer is prepared from the following materials in percent by weight: 93-99% of co-polypropylene, 0.5-5% of anti-mist agent and 0.5-2% of anti-blocking agent; the upper sublayer is prepared from the following material in percent by weight: 100% of anti-mist agent; the middle layer is prepared from the following materials in percent by weight: 95-99.5% of homo-polypropylene and 0.5-5% of anti-mist agent; the lower sublayer is prepared from the following material in percent by weight: 100% of anti-mist agent; and the lower layer is prepared from the following materials in percent by weight: 92.5-98.5% of co-polypropylene, 0.5-5% of anti-mist agent and 1.0-2.5% of anti-blocking agent. The biaxially-oriented polypropylene anti-mist film not only has good transparency, heat-sealing strength and printing effect, but also has excellent and durable anti-mist property, so that the service life is effectively prolonged.

Description

technical field [0001] The invention relates to a five-layer co-extruded biaxially stretched polypropylene anti-fog film and a manufacturing method thereof, belonging to the field of polymer materials. Background technique [0002] Vegetables, fruits, meat and frozen food, because of their high water content or large temperature difference, usually tend to form a layer of opaque water mist in the packaging bag. This layer of opaque water mist will prevent consumers from seeing the product clearly. It is impossible to visually judge the quality status of the product. In order to solve this problem, the packaging is usually packaged with an anti-fog film that prevents water vapor from forming fog on the surface of the film. However, the existing biaxially oriented polypropylene film with anti-fog function has a three-layer structure, which has the following disadvantages: (1) The anti-fog agent is blended with PP homopolymer or heat-sealing material and then extruded, and the...

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Problems solved by technology

However, the existing biaxially oriented polypropylene film with anti-fog function has a three-layer structure, which has the following disadvantages: (1) The anti-fog agent is blended with PP homopolymer or heat-sealing material and then extruded, and the anti-fog agent is completely separated out. It takes a certain amount of time, and it will take half a month to have a good effect. Therefore, it usually needs to be placed for half a month before it can be used to achieve a good anti-fog effect; (2) in the existing anti-fog film process formula , the effective content of the anti-fog agent is controlled within a small range, resulting in the persistence of the anti-fog effect is not long enough, often placed for 1 year, its anti-fog function will decline

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