RU2662207C2 - Method of improving barrier properties of plastic containers - Google Patents

Abstract

FIELD: package and storage.

SUBSTANCE: method relates to plastic containers with improved gas barrier properties, in particular to containers intended for the storage of food and non-food products, by the injection molding method and using the technology of the soldered label. Invention is a method allowing to create a single-layered plastic container with high gas barrier properties, which does not require complicated technology of creating a material for production, does not require complex equipment. This method is realized with the help of automatic devices for casting plastic containers by injection molding or by blowing into a mold and looks as follows: successively before the beginning of the cycle of casting or blowing, any prepared, sliced or cut out necessary sizes and patterns are inserted into the mold, gas barrier film and then, under pressure, molten plastic is injected or under pressure it is blown out of the heated plastic blank container and due to the action of high temperature, the film is soldered into the container, at the same time, plastic of any composition suitable for storage of a suitable food or non-food product may be used, gas barrier film should be fused along the perimeter of the container – into the walls, the bottom – and occupy not less than 90 % of the surfaces of the container; gas barrier film should contain more than one layer, the first layer in contact with the container must be made of the same material as the container or be coated, which, when heated, has good adhesion to the plastic container due to fusion, the second layer must have barrier properties, which can be aluminum, the spraying of an ethylene-vinyl alcohol copolymer or other barrier material; the following layers can be protective from the mechanical or chemical effects of the barrier layer of the film and serve to decorate the label.

EFFECT: due to the fusion of the gas barrier film between the surface of the container and the film, there is no distance and the possibility of peeling off such a film, making one container and a gas barrier film, leads to the occurrence of high gas barrier properties in the container and increases the rigidity of such a container.

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Description

FIELD OF THE INVENTION

The invention relates to plastic containers with improved gas barrier properties, in particular to containers intended for storing food and non-food products obtained by injection molding and using the technology of a soldered label (InMoldLabelling).

State of the art

Given that the Method uses several technologies and methods, in this section of the description, several analogues are indicated that together form a prototype.

Plastic products are used in various fields of light and heavy industry and are used in mechanical parts, automotive parts, parts of electrical fittings and electronic equipment, in containers for food and medicine. Such widespread use of plastic products is due to the many useful properties of this material, including: ease of processing and, as a result, the ability to give the product any shape; low cost of production compared to metal or glass; resistance to damage (does not break, flexible, can restore its original shape); production speed.

For the production of plastic products, various molding methods are used, namely:

- blowing into the mold (there are many such methods, one of them is given in patent No. 2507068, information on this patent is available on the FIPS official website at http://www1.fips.ru in the section: “Open registries”);

- vacuum molding (information about this method is taken from the official Wikipedia website located at:

https://en.wikipedia.org/wiki/%D0%92%D0%B0%D0%BA%D1%83%D1%83%D0%BC%D0%BD%D0%B0%D1%8F_%D1 % 84% D0% BE% D1% 80% D0% BC% D0% BE% D0% B2% D0% BA% D0% B0);

- injection molding (information on this method is taken from the official Wikipedia website located at:

https://en.wikipedia.org/wiki/%D0%9B%D0%B8%D1%82%D1%8C%D1%91_%D0%BF%D0%BE%D0%B4%D0%B4%D0 % B0% D0% B2% D0% BB% D0% B5% D0% BD% D0% B8% D0% B5% D0% BC):

- hot stamping (information about this method is taken from the official Wikipedia website located at:

https: en.wikipedia.org/wiki/%D0%A8%D1%82%D0%B0%D0%BC%D0%BF%D0%BE%D0%B2%D0%BA%D0%B0).

It does not make sense to describe the advantages and disadvantages of these molding methods in this description, because each of these methods is suitable for a specific container production (for example, PET bottles are most advantageously produced by blowing into a mold, but this method is not suitable for the manufacture of rigid plastic containers for non-liquid food products. It is best suited for the manufacture of containers for non-liquid food products injection molding method, etc.). For the Method described herein, only the injection molding method or the blow molding method can be used.

Given that the essence of the Method is to impart barrier properties to plastic containers, it is necessary to consider known methods of imparting barrier properties to plastic containers.

Basically, the barrier properties of plastic are imparted by changing its composition by adding special additives (one example of this method is disclosed in Russian patent No. 2434798. Information on this invention was taken from the FIPS official website at: http://www1.fips.ru in the section: "Open registries") or use in the manufacture of materials that prevent the penetration of gas into the container by applying them to the inner or outer surfaces (one of such methods is disclosed in Russian patent No. 2446952. Information on this patent is posted on and on the official FIPS website at: http://www1.fips.ru in the section: “Open registries”). This paragraph provides analogues of the Method. But it is not possible to isolate a prototype from them, because despite the coincidence of the purpose of the Method and the analogues, the Method is fundamentally different from analogues in the form of production. Therefore, the advantages and disadvantages of these analogues are discussed below.

Russian patent 2434798 discloses an invention relating to a container with improved barrier properties for packaging food and beverages. The container is obtained by blow molding and drawing the billet from the polyester composition. The polyester composition contains a polyester - polyethylene terephthalate and a purine derivative of the formula as a gas barrier additive. Preferably, the purine derivative is a purindion, such as caffeine. EFFECT: invention makes it possible to obtain polyester containers with an increased coefficient of improvement of the barrier to carbon dioxide and oxygen, without reducing the intrinsic viscosity or transparency of the container. This invention allows you to create a container with high barrier properties for food products, but to create it requires a complex composition of plastic and no less sophisticated equipment for its production.

Russian patent No. 2446952 discloses an invention relating to a container with improved gas barrier properties., Manufactured by multilayer blow molding and stretching, which includes at least two outer layers containing a polymer matrix. The polymer matrix contains polyester, polyamide, polyolefin, polyimide, polylactide or their derivatives. The multilayer blow molded and exhaust molded container includes at least one barrier layer located between at least two outer layers. One barrier layer contains a first polymer composition comprising a polymer matrix and a low molecular weight additive that improves gas barrier properties. The low molecular weight additive is a purine derivative having a molecular weight of less than 1000 daltons. Despite the great advantage of this invention, which is to increase the shelf life of the contents of the container, the production of the latter also requires sophisticated equipment and an expensive additive, the so-called polymer matrix.

Also prior art needs to consider the technology of fused labels (InMoldLabelling). This technology has been known for over 20 years and is used exclusively for attaching labels to the container.

There is a lot of information about this technology on the Internet.

The essence of this technology is that the label is applied to the surface of the container, and this happens simultaneously with the process of manufacturing plastic packaging in an injection machine. Under the influence of temperature, the label is melted into the container at the time of molding. After casting, the IML label forms a single unit with the material from which the packaging is made (usually the same plastics - high-pressure polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET) or polyvinyl chloride (PVC). The best option is when the label and containers are made of the same material.

Only two molding methods are suitable for applying this technology: the injection molding method and the method of blowing into the mold. However, to use this technology of labeling, a special IML is required - a label that is not produced in the Russian Federation, because its composition is unique. This technology has many advantages, including the high speed of production of plastic containers with printed images, attractive appearance, which makes it possible to advertise the products of the manufacturer and the manufacturer, increase the rigidity of the container on which such a label is attached. But with all the advantages of this technology, it does not give any barrier properties to the container and is expensive, because not produced in the Russian Federation.

Because The method includes all of these analogues, it is not possible to isolate any closest analogue.

The technical problem to be solved by the Method consists in the absence of a Method allowing to create a single-layer plastic container with high gas-barrier properties, which does not require complicated technology for creating material for production, does not require complex equipment for production and which can be made from materials produced in Russia Federation.

The reasons that serve as an obstacle to the solution of this technical problem are the complexity and high cost of equipment and materials used to give gas-barrier properties to plastic containers, the lack of production of IML labels in the Russian Federation, as well as the large statics of the barrier films that hold them together and interfere with the use of the Method on an industrial scale.

Disclosure of the invention

The invention is a method that allows you to create a plastic container with high gas barrier properties, which does not require sophisticated technology for creating material for production, does not require sophisticated equipment for production and which can be made from materials produced in the Russian Federation. This method is implemented using automatic apparatus for molding plastic containers by injection molding or by blowing into a mold and looks as follows: sequentially, before the start of the casting or blowing cycle, any prepared, cut or chiseled desired size and pattern gas barrier film is inserted into the mold and thereafter, molten plastic is injected under pressure or the container is blown out from the heated plastic preform under pressure and due to exposure to high temperature the film is soldered into the container, plastic of any composition that meets the requirements for storing the corresponding food or non-food product can be used, the gas barrier film must be fused along the entire perimeter of the container - into the walls, the bottom and occupy at least 90% of the container surfaces; the gas barrier film must contain more than one layer, the first layer in contact with the container must be made of the same material as the container or have a coating that, when heated, has good adhesion to the plastic container due to fusion, the second layer must have barrier properties, which can be aluminum, spraying a copolymer of ethylene and vinyl alcohol or other barrier material; the following layers can be protective against mechanical or chemical effects of the barrier layer of the film, for decorating labels. Due to the fusion of the gas barrier film between the surface of the container and the film, there is no distance and the possibility of delamination of such a film, which makes the container and the gas barrier film integer and leads to the formation of high gas barrier properties in the container and increases the rigidity of such a container.

Brief Description of the Drawings

The figure No. 1 shows a plastic container, with an embedded barrier film of 3 layers. The figure No. 2 shows an example of fusion of a barrier film when using the injection molding method. The figure No. 3 shows an example of fusion of a barrier film using the method of blowing into the mold. The figure No. 4 in an enlarged view shows the wall of the container with an embedded barrier film and the layers of such a film.

The implementation of the invention

The method is intended for the manufacture of a container with high barrier (gas tight) properties, from plastic made from domestic materials in the Russian Federation.

In particular forms of implementing the Method, various methods of forming containers are used. In all the following forms of implementation of the Method, a gas barrier film made of biaxially oriented polypropylene (BOPP film) (2) laminated with aluminum foil (3), or another film of which one of the outer layers is polypropylene (2) is used, but both of which contain such a film the barrier layer (3) which can be aluminum, spraying a copolymer of ethylene and vinyl alcohol or another barrier layer, as well as their combinations.

In one of the private forms of implementation of the Method, such a molding method as injection molding is used, in this method single-layer molding is used. This method is carried out on injection molding machines (4). To use the injection molding machine, it is first necessary to prepare (cut) the barrier film of the required size. It is necessary to insert the film manually, i.e. an operator is needed for this process. In this way, the problem of high static is avoided and, as a result, the adhesion of barrier films to one another is eliminated, which makes it possible to apply this method on an industrial scale. After the film is captured by the operator of the injection molding machine, the film is smoothed over the matrix of the forming arm and due to the static, the film adheres to the walls of the mold without a gap (5), after which molten plastic is fed and the mold is closed from the casting channel under high pressure (1). In the mold, the plastic is fused with a barrier film (2, 3), cools and a finished product is obtained.

To verify this form of implementation, an experiment was conducted and experimental models of a plastic container with high gas-tight (barrier) properties were created. Such a container is created by single-layer molding. The barrier film is firmly attached to the surface of such a container and is integral with the container. At the same time, the stiffness of the container increased, and the information and images printed on the barrier film remained of high quality, which also gives additional opportunities to apply the necessary product information to the end user.

In another particular embodiment of the Method, a molding method such as blowing into a mold is used. This method is carried out on blowing machines (6). To use the blowing machine, it is first necessary to prepare (cut) the barrier film of the desired size and pattern. It is necessary to insert the film manually, i.e. an operator is needed for this process. In this way, the problem of high static is avoided and, as a result, the adhesion of barrier films to one another is eliminated, which makes it possible to apply this method on an industrial scale. Before blowing the container onto the film, hot melt glue must be applied to fuse with the container. After that, the heated preform is fed and under high pressure the container is inflated into which the barrier film is melted due to the high temperature (2, 3).

The above are known forms of implementation of the Method. It should be borne in mind that with the development of the prior art, the methods and forms of implementation of this Method may change, however, the essence of the invention, which consists in the Method of imparting barrier properties to a plastic container from changing methods and forms, will not change.

Claims (1)

A method for improving the barrier properties of plastic containers, including the use of barrier films, methods for forming plastic containers in the form of injection molding or blowing into a mold, as well as an injection-molded technology, characterized in that it is inserted into the mold sequentially before the start of the molding or blowing cycle. any prepared gas barrier film and then molten plastic is injected under pressure or the container is blown out from a heated plastic preform under pressure, under the influence of high At this temperature, the film is soldered into the container, plastic of any composition that meets the requirements for storing the corresponding food or non-food product can be used, the gas-barrier film must be fused along the entire perimeter of the container — into the walls, the bottom — and occupy at least 90% of the container’s surfaces , the gas barrier film must contain more than one layer, the first layer in contact with the container must be made of the same material as the container, or have a coating that, when heated, it has good adhesion to the plastic container due to fusion, the second layer must have barrier properties, which can be aluminum, spraying a copolymer of ethylene and vinyl alcohol or other barrier material, the following layers are protective from mechanical or chemical effects of the film's barrier layer or serve label decoration.

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