Three-layer co-extruded oxygen absorbing thin film for food package and preparation method thereof

Abstract

The invention relates to a three-layer co-extruded oxygen absorbing thin film for a food package and a preparation method thereof, and belongs to the technical field of packaging materials. The upper layer is unmodified polyethylene or polypropylene resin, the lower layer is a food contact layer which is prepared from polyethylene or polypropylene resin modified by an ethylene-vinyl acetate copolymer (EVA), and the core layer is an oxygen absorbing resin which is prepared from polyethylene or polypropylene resin containing natural rubber or ferrite of an iron-based catalyst. The three layers of substances are extruded and moulded in one step to prepare a raw material thin film with the oxygen absorbing function by means of a three-layer co-extrusion film blowing or curtain coating device. The thin film is used to preserve fresh oxygen-sensitive food, so that the shelf life and the storage period of food are improved. The thin film is simple in production process and can be produced by existing devices.

Description

technical field [0001] The invention relates to an oxygen-absorbing film for food packaging and a preparation method thereof. More specifically, the application relates to a three-layer co-extruded film, the core layer of which contains natural rubber and iron-based catalysts, and the flexible packaging film obtained by dry laminating the three-layer co-extruded film with an ordinary high-barrier film has the ability to absorb oxygen. The function is used for the packaging of cooked food, especially suitable for fresh-keeping storage of oxygen-sensitive food, and belongs to the technical field of packaging materials. Background technique [0002] There are many foods that are very sensitive to oxygen. For example, when the oxygen concentration in beer reaches 0.6ppm, the taste will be greatly reduced and the commodity value will be lost. Other oxygen-sensitive foods include fruit juice, jam, cheese, etc., all of which require high-barrier packaging materials In recent years...

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Problems solved by technology

[0002] There are many foods that are very sensitive to oxygen. For example, when the oxygen concentration in beer reaches 0.6ppm, the taste will be greatly reduced and the commodity value will be lost. Other oxygen-sensitive foods include fruit juice, jam, cheese, etc., all of which require high-barrier packaging materials In recent years, a series of packaging materials with oxygen absorption function have been successfully developed in the world, but the cost is relatively high. This kind of oxygen absorption packaging with active oxygen scavenging function can 100% eliminate the permeation of oxygen from the outside to the packaging, and the oxygen in the packaging. Headspace oxygen, as well as dissolved oxygen in food, prevents food from being oxidized, maintains food quality, and prolongs the shelf life and storage life of food

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