Seven-layer co-extrusion functional packaging film

Abstract

The invention relates to the technical field of packaging materials, in particular to a seven-layer co-extrusion functional packaging film which comprises a packaging film body, the packaging film body comprises a PA layer, a Tie layer, a PA layer, a Tie layer, a PP and PE weather-proof layer, a PP and PE anti-pollution layer and a PP and PE heat sealing layer, and the PA layer, the Tie layer, the PA layer, the Tie layer, the PP and PE weather-proof layer, the PP and PE anti-pollution layer and the PP and PE heat sealing layer are arranged from inside to outside. The seven-layer co-extrusion functional packaging film can be applied to the fields of food, medical treatment, daily necessities, military industry, chemical industry and the like; the packaging can resist water boiling at 105 DEG C, cooking at medium temperature of 121 DEG C and cooking at ultrahigh temperature of 135 DEG C, and can also bear freezing at extremely cold temperature of-50 DEG C; pP and PE are arranged on the outer layer, production of down-blowing water-cooling equipment is facilitated, PP and PE raw materials can generate oxides after being extruded at high temperature and high pressure, and objects in the package are better protected from being polluted after being washed with water.

Description

Technical Field

[0001] The invention relates to the technical field of packaging materials, in particular to a seven-layer co-extruded functional packaging film. Background Art

[0002] In the film processing, one raw material is extruded onto another film that has been made, or different types of films that have been made are bonded together to form a multilayer film. This product is called a composite film. Most of the materials of composite films are plastics, but paper, metal foil (usually aluminum) or fabric can also be used. The basic requirement of composite films is that there must be good adhesion between layers to ensure the overall performance of the packaging. In addition, composite films are mostly used for food packaging. Adhesives must be used in the processing of composite films. The selection of solvents and bonding processes must meet the corresponding hygiene standards. Co-extruded films have most of the characteristics of composite films. Since the layers are bonded by hot melt without the need for adhesives, the hygiene and safety of co-extruded films for food packaging are relatively reliable. The co-extruded functional film has the following characteristics during the processing. After stretching, the strength can be increased accordingly. Plastic materials such as nylon, metallocene polyethylene, metallocene polypropylene, and SEBS elastomer can also be added to make it have a composite strength and toughness that exceeds that of general plastic packaging. It can be recycled and there is no delamination and peeling phenomenon. It can not only meet the requirements of being resistant to boiling at 105°C and high temperature cooking at 121°C, but also withstand extremely cold freezing at -50°C, ultraviolet rays, and pasteurization while maintaining excellent heat sealing performance. The scientific name of PA6 is "polyamide". It is a non-toxic, odorless, safe and reliable high barrier material. In addition to the general properties of plastics, it also has the characteristics of oil resistance, corrosion resistance, and oxygen resistance. It can be widely used in food, medical, daily necessities packaging and other industries.

[0003] The existing PA6 raw material co-extruded film cannot be co-extruded using a single material, so the present invention provides a seven-layer co-extruded functional packaging film. Summary of the invention

[0004] The object of the present invention is to solve at least one of the technical drawbacks.

[0005] To this end, an object of the present invention is to provide a seven-layer co-extruded functional packaging film to solve the problems mentioned in the background technology and overcome the shortcomings of the prior art.

[0006] In order to achieve the above-mentioned objectives, an embodiment of one aspect of the present invention provides a seven-layer co-extruded functional packaging film, including a packaging film body, wherein the packaging film body includes a PA layer, a Tie layer, a PA layer, a Tie layer, a PP and PE weather-resistant layer, a PP and PE anti-pollution layer, and a PP and PE heat-sealing layer.

[0007] The present invention is further configured as follows: the PA layer, Tie layer, PA layer, Tie layer, PP and PE weather-resistant layers, PP and PE anti-pollution layers, and PP and PE heat-sealing layers are arranged from inside to outside.

[0008] By adopting the above technical solution, PP and PE are arranged on the outer layer, which is helpful for the production of downward blowing water cooling equipment.

[0009] The present invention is further configured as follows: the interlayer thickness ratios of the PA layer, Tie layer, PA layer, Tie layer, PP and PE weather-resistant layer, PP and PE anti-pollution layer, and PP and PE heat-sealing layer are: 12%, 10%, 13%, 10%, 20%, 18%, and 17%.

[0010] The present invention is further configured as follows: the packaging film body is prepared by a multi-layer co-extrusion die, and the multi-layer co-extrusion die has a core rod and a mold core.

[0011] The present invention is further configured as follows: a plurality of mold layers for extruding different materials are arranged on the periphery of the core rod.

[0012] The present invention is further configured as follows: a flow channel from the molten thermoplastic material inlet to the annular extrusion outlet is arranged in the mold layer, and the flow channel is formed by core blow molding and water cooling.

[0013] The present invention is further configured as follows: each layer of the mold layer is provided with a flow channel connected to the extruder, and the flow channel forms a clamp shape at the center.

[0014] The present invention is further configured as follows: the flow channels of the PP and PE extrusion layers, the PA extrusion layer and the Tie extrusion layer in the flow channel all adopt a one-to-two, two-to-four, or four-to-eight disc-shaped short spiral flow channel.

[0015] In summary, the beneficial technical effects of the present invention are:

[0016] The seven-layer co-extruded functional packaging film can be used in food, medical, daily necessities, military, chemical and other fields; the packaging can withstand boiling at 105℃, medium temperature cooking at 121℃, ultra-high temperature cooking at 135℃, and can also withstand extreme freezing at -50℃; PP and PE are arranged on the outer layer to facilitate the production of downward blowing water cooling equipment. PP and PE raw materials will produce oxides after high temperature and high pressure extrusion, and after water washing, the contents in the packaging will be better protected from contamination;

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] Embodiment 1

[0020] The present invention discloses a seven-layer co-extruded functional packaging film, comprising a packaging film body, wherein the packaging film body comprises a PA layer, a Tie layer, a PA layer, a Tie layer, a PP and PE weather-resistant layer, a PP and PE anti-pollution layer, and a PP and PE heat-sealing layer, wherein the PA layer, the Tie layer, the PA layer, the Tie layer, the PP and PE weather-resistant layer, the PP and PE anti-pollution layer, and the PP and PE heat-sealing layer are arranged from inside to outside, and the interlayer thickness ratios of the PA layer, the Tie layer, the PA layer, the Tie layer, the PP and PE weather-resistant layer, the PP and PE anti-pollution layer, and the PP and PE heat-sealing layer are 12%, 10%, 13%, 10%, 20%, 18%, and 17%, and the packaging film body is prepared by a multi-layer co-extrusion die, and the multi-layer co-extrusion die has a core rod and a mold core, and the outer periphery of the core rod is A plurality of mold layers for extruding different materials are provided, a flow channel from the inlet of the molten thermoplastic material to the annular extrusion outlet is provided in the mold layer, and the flow channel is formed by core blow molding and water cooling, each layer of the mold layer is provided with a flow channel connected to the extruder, and the flow channel forms a clamp shape at the center, and the flow channels of the PP and PE extrusion layers, the PA extrusion layer and the Tie extrusion layer in the flow channel all adopt a disc-shaped short spiral flow channel of one-to-two, two-to-four, and four-to-eight. In this embodiment, PP and PE are provided in the outer layer to facilitate the production of downward blowing water cooling equipment. In this embodiment, the mold has a plurality of annular or conical core rods, and a plurality of mold layers for extruding different materials are provided on the periphery of the core rods; a flow channel from the inlet of the molten thermoplastic material to the annular extrusion outlet is provided in the mold layer; and it is formed by core blow molding and water cooling.

[0021] The implementation principle of this embodiment is:

[0022] The prior art is all about the technical inventions of co-extrusion of PE raw materials and EVA with PA raw materials. This film cannot be used for packaging of products sterilized at medium temperature of 121°C and high temperature of 135°C and -50°C, which has great limitations. In order to make the packaging materials more adaptable to environmental factors, the present invention provides a formula structure of this seven-layer co-extruded functional packaging film. PP and PE are arranged in the outer layer to facilitate the production of downward blowing water cooling equipment. PE and EVA raw materials are not used because these materials cannot withstand the sterilization requirements of medium temperature of 121°C and high temperature of 135°C. Therefore, the device has certain practicality.

[0023] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A seven-layer co-extruded functional packaging film, characterized in that: It comprises a packaging film body, which comprises a PA layer, a Tie layer, a PA layer, a Tie layer, a PP and PE weather-resistant layer, a PP and PE anti-pollution layer, and a PP and PE heat-sealing layer.

2. The seven-layer co-extruded functional packaging film according to claim 1, characterized in that: The PA layer, Tie layer, PA layer, Tie layer, PP and PE weather-resistant layers, PP and PE anti-pollution layers, and PP and PE heat-sealing layers are arranged from inside to outside.

3. The seven-layer co-extruded functional packaging film according to claim 1, characterized in that: The interlayer thickness ratios of the PA layer, Tie layer, PA layer, Tie layer, PP and PE weather-resistant layer, PP and PE anti-pollution layer, and PP and PE heat-sealing layer are: 12%, 10%, 13%, 10%, 20%, 18%, and 17%.

4. The method for preparing a seven-layer co-extruded functional packaging film according to claim 1, characterized in that: The packaging film body is prepared by a multi-layer co-extrusion die, and the multi-layer co-extrusion die has a core rod and a mold core.

5. The method for preparing a seven-layer co-extruded functional packaging film according to claim 4, characterized in that: The periphery of the core rod is provided with multiple layers of mold layers for extruding different materials.

6. The method for preparing a seven-layer co-extruded functional packaging film according to claim 5, characterized in that: A flow channel from the molten thermoplastic material inlet to the annular extrusion outlet is arranged in the mold layer, and the flow channel is formed by core blow molding and water cooling.

7. The method for preparing a seven-layer co-extruded functional packaging film according to claim 6, characterized in that: Each layer of the mold layer is configured with a flow channel connected to an extruder, and the flow channel forms a clamp shape at a center position.

8. The method for preparing a seven-layer co-extruded functional packaging film according to claim 7, characterized in that: The flow channels of the PP and PE extrusion layers, the PA extrusion layer and the Tie extrusion layer in the flow channel all adopt a disc-shaped short spiral flow channel with one divided into two, two divided into four, and four divided into eight.