Packaging film for milk and method for manufacturing same

Abstract

A milk packaging film is a composite film formed by binding an outer film and an inner film via a binder layer. The outer film is a polyvinylidene chloride film, the binder is mono-component or two-component polyurethane solvent binder or non-solvent binder, and the inner film is a black and white polyethylene film. The manufacturing method of the milk packaging film comprises the steps of heating the outer polyvinylidene chloride film via a heating device; placing on an unwinding shaft of a film-coating machine; passing through an unwinding machine; adjusting via a flattening device, a tension control device and an edge guide device; coating binder; and laminating with the inner film treated by the flattening device, the tension control device and the edge guide device. The inventive milk packaging film has the advantages of high heat-sealing strength, high mechanical strength, stable chemical properties, resistance to oil and fat, solvent, acids, bases and salts, no chemical reactions with foods, good food sanitation performance, high-temperature steaming resistance, no deformation, no cracking, good printability, and low cost.

Description

technical field [0001] The invention designs a packaging material, in particular relates to a milk packaging film; meanwhile, it relates to a preparation method of the packaging film. Background technique [0002] With the sustained, steady and rapid growth of my country's national economy and the continuous improvement of people's living standards, major changes have taken place in lifestyles, consumption habits and dietary structures, and health awareness has become stronger and stronger. The diet requires both nutrition and safety. health. Because milk is rich in nutrients such as protein, vitamins and minerals, it is easy to be digested and absorbed by the human body, and it is convenient to carry and drink, which is in line with the fast pace of modern life. Therefore, milk products are more and more popular among consumers. Liquid milk will be the mainstream of milk product consumption in the future. Liquid milk includes pasteurized milk and UHT milk. The nutritional...

AI Technical Summary

Problems solved by technology

[0003] At present, in the existing domestic packaging industry, the packaging of high-end products uses a high-barrier composite packaging film with aluminum foil as the middle layer. It is made of biaxially oriented polyester film, adhesive, aluminum foil, adhesive, cast poly Composed of acrylic film, the aluminum foil composite packaging film has very high barrier properties, and with printed patterns, the product looks beautiful, and this packaging film can be sterilized by high temperature and high pressure cooking; however, aluminum foil film still has many shortcomings: 1. In the process of packaging and circulation, discounts and cracks are easy to occur, causing the aluminum foil film to be broken and lose its barrier performance; 2. Aluminum foil film often has pinholes in the preparation process; 3. The cost is high

Some products are also packaged with EVOH multi-layer co-extrusion film. The disadvantages of this packaging film are: 1. It can only be printed on the surface, and it is prone to ink loss; 2. EVOH is greatly affected by environmental conditions. Humidity with the external environment should not exceed 70%, and EVOH materials are easy to absorb water, resulting in a significant decline in the barrier properties of EVOH multi-layer co-extruded films, which cannot protect the product; therefore, these packaging films are not suitable for packaging milk

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