Thinned high-barrier liquid packaging film and manufacturing method thereof

Abstract

The invention relates to a thin-reducing and high impermeable liquid packaging membrane and a manufacturing method thereof. The product comprises a polyvinyl basilar membrane, a high impermeable polyvinyl alcohol layer, a composite adhesive layer and a protective polythene membrane layer, wherein, the polyvinyl basilar membrane comprises an outer layer, a middle layer and an inner layer and the outer layer and the middle layer comprise at least one of the two materials which are medium-density polythene or high-density polythene. The manufacturing method of the product comprises the steps of the preparation of the polyvinyl basilar membrane, the preparation of polyvinyl alcohol coating liquid and the preparation of the protective polythene membrane layer, coating and compounding, wherein, the polyvinyl alcohol coating liquid is diluted and the diluted polyvinyl alcohol coating liquid is coated on the outer layer of the polyvinyl basilar membrane to form the high impermeable polyvinyl alcohol layer and then the protective polythene member layer and the polyvinyl alcohol coating layer are compounded, cured and cut. The product of the invention has low thickness, good rigidness, high impermeable property, environmental protection, convenient use, low cost and simple technique.

Description

technical field [0001] The invention relates to a thinned high-barrier liquid packaging film and a manufacturing method thereof, in particular to a thinned polyethylene, polyvinyl alcohol high-barrier liquid packaging film and a manufacturing method thereof. Background technique [0002] With the increasingly fierce competition in the liquid food market and the rising price of plastic raw materials for packaging, liquid food manufacturers have higher and higher requirements for the production cost and oxygen barrier and fresh-keeping performance of plastic packaging materials for packaging. How to reduce the production cost of packaging materials , and can prolong the shelf life and shelf life of the contents to meet the packaging requirements of liquid food, which is one of the problems to be solved in the field of liquid food packaging materials today. [0003] Most of the liquid packaging films currently used in the market are produced by high-pressure polyethylene (LDPE)...

AI Technical Summary

Problems solved by technology

However, since polyvinyl alcohol is a water-soluble resin, the water resistance is poor, and the gas barrier performance plummets under high-humidity conditions.

If a layer of modified polyvinyl alcohol is coated on the polyethylene-based film, a more rigid material is used as a protective layer, such as thin aluminum sheet, aluminized film, polyethylene terephthalate (PET), Chlorinated polypropylene (CPP), biaxially oriented polypropylene (BOPP), etc., can maintain the barrier properties of the composite film at a certain humidity, while improving rigidity, and the film thickness is low, which is indeed progressive, but in actual use At that time, it was found that there were still some shortcomings in its structure, which caused the high barrier liquid packaging film to fail to achieve the best use effect in practical application, and its shortcomings can be summarized as follows:

[0006] 1. The polyethylene film used for the base film has poor rigidity, so it is necessary to use relatively high-priced materials such as PET, BOPP, CPP, and aluminized film with good rigidity as the protective layer to make up for its deficiency, which increases production costs;

[0007] 2. The characteristics of the raw materials used for the base film and the protective layer film are different, and the temperature difference of each layer of film is large. In actual production, it is easy to have wire drawing and bag connection, resulting in an increase in damage rate;

[0008] 3. Due to the high temperature of horizontal sealing, the horizontal sealing die head maintains high temperature for a long time, which shortens the service life of the packaging machine;

[0009] 4. Due to the different operating temperatures of the materials used, they are basically not recyclable, and the harmful gases produced during incineration are not conducive to environmental protection

[0010] This shows that the above-mentioned existing high barrier liquid packaging film obviously still has inconvenience and defects in production and use, and needs to be further improved urgently.