Recyclable high-barrier packaging film and preparation method thereof

Abstract

The recoverable high-barrier packaging film comprises a biaxially oriented polypropylene layer, a barrier layer and a heat-sealing layer which are sequentially arranged from outside to inside, the heat-sealing layer comprises a composite layer, a middle layer and a heat-sealing inner layer, and the composite layer comprises, by mass, 40-60% of high-density polyethylene and 40-60% of metallocene linear low-density polyethylene. The middle layer comprises 60-70% of low-density polyethylene, 25-35% of linear low-density polyethylene and 1-5% of an opening slipping agent, and the heat-sealing inner layer comprises 30-50% of linear low-density polyethylene, 20-40% of metallocene linear low-density polyethylene, 5-10% of a polyolefin plastomer, 5-15% of a polyolefin elastomer, 5-10% of low-density polyethylene and 3-8% of an opening slipping agent. The invention further discloses a preparation method of the recyclable high-barrier packaging film. Three layers of stacked polyethylene films are adopted as heat sealing layers, and each layer of film adopts a unique formula design, so that the packaging film is easy to process during preparation, the barrier property and the heat sealing property of the packaging film are improved, and the mechanical property is also improved.

Description

technical field [0001] The invention relates to the technical field of food packaging films, in particular to a recyclable high-barrier packaging film and a preparation method thereof. Background technique [0002] Packaging film is widely used in various fields of life, such as food, medicine, cosmetics, etc. It is mainly used to protect products from moisture absorption, moisture, oxidation, etc., which will cause product deterioration. When used in different fields, the requirements for packaging films are also different. For example, medical products often require packaging films to be antibacterial and have good water and oxygen barrier properties. Electronic products require packaging films to be puncture-resistant and anti-static. For most food packaging films In terms of water and oxygen barrier properties, it is an important criterion for evaluating the performance of packaging films, especially for some products that are prone to moisture and oxidation, such as bis...

AI Technical Summary

Problems solved by technology

However, with the introduction of the environmental protection economy, researchers have found that it is very difficult to recycle aluminum foil packaging film, mainly in the following aspects: first, it is difficult to recycle aluminum foil; second, the packaging film is made of different materials through adhesive curing. , It is very difficult to separate, and different materials cannot be recycled when they are solidified together, and have no recycling value. After use, they can only be discarded, which causes great environmental pollution. Third, adhesives usually contain some harmful substances, which are harmful to human health and environment is a threat

[0004] In recent years, packaging films made of aluminized film instead of aluminum foil have been used more and more in food and other fields. Compared with aluminum foil, the thickness of the aluminized layer in aluminized film is thinner, although it solves the problem that aluminum foil is difficult to recycle. , but due to its poor barrier properties to water vapor and oxygen, its application in many aspects is still limited

Some researchers used polyethylene as the heat-sealing layer and modified the heat-sealing layer. Although the barrier performance of the packaging film to water and oxygen was improved as a whole, due to the introduction of other materials during modification, the modified polyethylene There are problems such as high melting point and difficult blow molding during film processing, which affect the production of packaging film, resulting in a decline in the overall performance of packaging film products and a decrease in product yield

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