Composite cast film

Abstract

The utility model relates to the technical field of cast films, in particular to a composite cast film which is characterized in that a barrier layer is fixedly arranged on the upper surface of a base layer, the barrier layer comprises a barrier film and a plurality of graphene sheets, the graphene sheets are fixedly arranged in the barrier film in an end-to-end connection mode, barrier gas penetrates through the barrier layer, and a protective layer is fixedly arranged on the upper surface of the barrier layer. Gas overflowing from the barrier layer is prevented from penetrating through the cast film; the base layer has relatively high tensile strength, so that the package integrity of the cast film is ensured, and meanwhile, a primary isolation effect on gas in the package is achieved; the graphene sheets connected end to end form a complete graphene layer in the barrier film, the barrier film is divided into an upper part and a lower part in the vertical direction, a gas channel in the barrier film is blocked, and gas is effectively prevented from overflowing; the protective layer intercepts the gas, the gas isolation capacity of the cast film is enhanced again, leakage of the gas in the package of the cast film is reduced, the surface layer reflects external light, the influence of illumination on packaged articles is reduced, and the preservation time of the packaged articles is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of cast film technology, and in particular to a composite cast film. Background Technology

[0002] Cast film is a type of non-stretched, non-oriented flat extrusion film produced by rapidly cooling a melt. There are two methods: single-layer casting and multi-layer co-extrusion. Compared to blown film, it features faster production speed, higher output, and superior transparency, gloss, and thickness uniformity. Cast film possesses excellent heat-sealing properties and superior transparency, making it one of the main packaging composite substrates used in the production of high-temperature retort films, vacuum metallized films, etc. Composite-grade cast film is produced by multi-layer co-extrusion technology, combining two or more plastic raw materials with different properties (such as polyethylene, polypropylene, polyester, etc.) in a molten state, followed by casting, cooling, traction, and winding processes.

[0003] Traditional cast films often have gas leakage. To reduce gas leakage, the thickness of the cast film is increased. Thicker cast films have greater hardness, which is not conducive to packaging. Summary of the Invention

[0004] The main objective of this invention is to provide a composite cast film to solve the problem that the thickened cast film has high hardness, which is not conducive to packaging and forming, as proposed in related technologies.

[0005] To achieve the above objectives, according to one aspect of the present invention, a composite cast film is provided, comprising: a base layer, wherein the base layer maintains the integrity of the cast film;

[0006] A barrier layer is fixedly disposed on the upper surface of the base layer. The barrier layer includes a barrier film and several graphene sheets. The graphene sheets are all fixedly disposed inside the barrier film with their ends connected, thus preventing gas from passing through the barrier layer.

[0007] A protective layer is fixedly disposed on the upper surface of the barrier layer to prevent gas escaping from the barrier layer from passing through the cast film.

[0008] The surface layer is fixed on the upper surface of the protective layer and reflects the light shining on the cast film.

[0009] Furthermore, the graphene sheet includes a group of horizontal sheets, vertical sheets, and oblique sheets, with the vertical sheets fixedly disposed at the rear end of the horizontal sheets.

[0010] Furthermore, the inclined plate assembly includes an inclined plate and a notch. The inclined plate is fixedly disposed at the front end of the horizontal plate, the notch is disposed below the inclined plate, and the vertical plate can be inserted into the notch to connect the two graphene sheets.

[0011] Furthermore, the base layer is made of polyamide, and the thickness of the base layer is 0.01mm~0.02mm.

[0012] Furthermore, the barrier film is made of polypropylene, and the thickness of the barrier film is 0.02mm~0.03mm.

[0013] Furthermore, the protective layer is made of vinylidene chloride, and the thickness of the protective layer is 0.01 mm to 0.02 mm.

[0014] Furthermore, the surface layer is a layer of aluminum atoms stacked in a matrix on the upper surface of the protective layer.

[0015] Compared with the prior art, this utility model has the following beneficial effects: the base layer has high tensile strength, ensuring the integrity of the cast film packaging, and at the same time, it plays a preliminary role in isolating the gas inside the packaging; the graphene sheets connected end to end form a complete graphene layer inside the barrier film, dividing the barrier film vertically into upper and lower parts, blocking the gas channels inside the barrier film, and effectively preventing gas leakage; the protective layer intercepts the gas, further enhancing the gas isolation capability of the cast film, reducing the leakage of gas inside the cast film packaging, and the surface layer reflects external light, reducing the impact of light on the packaged items and extending their shelf life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall design of this utility model.

[0017] Figure 2 This is a cross-sectional view of the present invention.

[0018] Figure 3 This is a schematic diagram of the barrier layer structure of this utility model.

[0019] Figure 4 This is a schematic diagram of the graphene sheet structure of this utility model.

[0020] Illustration:

[0021] 1. Grassroots level;

[0022] 2. Barrier layer; 21. Barrier film; 22. Graphene sheet; 221. Horizontal sheet; 222. Vertical sheet; 223. Angled sheet; 224. Notch;

[0023] 3. Protective layer;

[0024] 4. Surface layer. Detailed Implementation

[0025] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0026] Please see Figures 1 to 4 This embodiment provides a composite cast film, including: a base layer 1, which maintains the integrity of the cast film;

[0027] Barrier layer 2 is fixedly disposed on the upper surface of base layer 1. Barrier layer 2 includes barrier film 21 and several graphene sheets 22. The graphene sheets 22 are all fixedly disposed inside barrier film 21 with their ends connected, thus preventing gas from passing through barrier layer 2.

[0028] Protective layer 3 is fixedly disposed on the upper surface of barrier layer 2 to prevent gas escaping from barrier layer 2 from passing through the cast film.

[0029] Surface layer 4 is fixed on the upper surface of protective layer 3 and reflects the light shining on the cast film.

[0030] The graphene sheet 22 includes a horizontal sheet 221, a vertical sheet 222 and an oblique sheet group, with the vertical sheet 222 fixedly disposed at the rear end of the horizontal sheet 221.

[0031] The oblique sheet assembly includes an oblique sheet 223 and a notch 224. The oblique sheet 223 is fixedly disposed at the front end of the horizontal sheet 221, and the notch 224 is disposed below the oblique sheet 223. The vertical sheet 222 can be inserted into the notch 224 to connect two graphene sheets 22. The graphene sheets 22 connected end to end are distributed horizontally in the barrier film 21, dividing the barrier film 21 into upper and lower parts, blocking the micropores inside, preventing gas molecules from passing through the micropores, and causing gas leakage from the cast film packaging.

[0032] The base layer 1 is made of polyamide, which has strong tensile strength and stretch strength, and can maintain the integrity of the cast film. The thickness of the base layer 1 is 0.01mm~0.02mm, and in this embodiment, a thickness of 0.015mm is preferred, which ensures the strength of the cast film while reducing its thickness.

[0033] The barrier membrane 21 is made of polypropylene, which is resistant to corrosion from acids, alkalis, salt solutions and various organic solvents. The thickness of the barrier membrane 21 is 0.02 mm to 0.03 mm, and in this embodiment, a thickness of 0.03 mm is preferred, so as to provide distribution space for the graphene sheet 22.

[0034] The protective layer 3 is made of vinylidene chloride. Vinylidene chloride has low internal porosity and strong gas barrier ability. The thickness of the protective layer 3 is 0.01mm~0.02mm. In this embodiment, a thickness of 0.02mm is preferred to enhance the gas barrier ability of the cast film.

[0035] The surface layer 4 is a layer of aluminum atoms stacked in a matrix on the upper surface of the protective layer 3. The aluminum atoms have a metallic luster and can reflect the light shining on the surface layer 4, preventing light from damaging the items inside the cast film packaging and extending the shelf life of the items.

[0036] When packaging items with cast film, the base layer 1 has high tensile strength, ensuring the integrity of the cast film packaging. At the same time, it plays a preliminary role in isolating the gas inside the packaging. Some gas passes through the base layer 1 and reaches the lower surface of the barrier layer 2, where it is isolated by the barrier film 21. A small amount of gas penetrates into the interior of the barrier film 21 and diffuses upward inside. The graphene sheet 22 intercepts this part of the gas again. The graphene sheets 22 connected end to end form a complete graphene layer inside the barrier film 21, dividing the barrier film 21 vertically into upper and lower parts, blocking the gas channels inside the barrier film 21, and effectively preventing gas leakage. After a very small amount of gas passes through the graphene sheet 22 and the barrier film 21, the protective layer 3 on the barrier layer 2 intercepts this part of the gas, further strengthening the gas isolation ability of the cast film and reducing the leakage of gas inside the cast film packaging. The surface layer 4 reflects external light, reducing the impact of light on the packaged items and extending their shelf life.

[0037] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A composite-grade cast film, characterized in that, include: Base layer (1), wherein the base layer (1) maintains the integrity of the cast film; Barrier layer (2), the barrier layer (2) is fixed on the upper surface of the base layer (1), the barrier layer (2) includes a barrier film (21) and a number of graphene sheets (22), the graphene sheets (22) are all connected end to end and fixed inside the barrier film (21) to block gas from passing through the barrier layer (2). The protective layer (3) is fixed on the upper surface of the barrier layer (2) to prevent gas overflowing from the barrier layer (2) from passing through the cast film; The surface layer (4) is fixed on the upper surface of the protective layer (3) and reflects the light shining on the cast film.

2. The composite cast film according to claim 1, characterized in that, The graphene sheet (22) includes a horizontal sheet (221), a vertical sheet (222) and an oblique sheet group, wherein the vertical sheet (222) is fixedly disposed at the rear end of the horizontal sheet (221).

3. The composite-grade cast film according to claim 2, characterized in that, The oblique plate group includes an oblique plate (223) and a notch (224). The oblique plate (223) is fixedly disposed at the front end of the horizontal plate (221), and the notch (224) is disposed below the oblique plate (223). The vertical plate (222) can be inserted into the notch (224) to connect the two graphene plates (22).

4. The composite cast film according to claim 1, characterized in that, The base layer (1) is made of polyamide and has a thickness of 0.01 mm to 0.02 mm.

5. The composite cast film according to claim 1, characterized in that, The barrier film (21) is made of polypropylene and has a thickness of 0.02 mm to 0.03 mm.

6. The composite-grade cast film according to claim 1, characterized in that, The protective layer (3) is made of vinylidene chloride and has a thickness of 0.01 mm to 0.02 mm.

7. The composite cast film according to claim 1, characterized in that, The surface layer (4) is a layer of aluminum atoms stacked in a matrix on the upper surface of the protective layer (3).

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