Packaging composite film for displaying freshness of pork

Abstract

The utility model discloses a packaging composite film capable of displaying pork freshness, which comprises a surface protection film layer, a corona PE (polyethylene) film layer, a hot-melt pressure-sensitive adhesive layer, a heat-seal PE film layer and an anthocyanin indication film layer, and the surface protection film layer and the hot-melt pressure-sensitive adhesive layer are respectively arranged on two sides of the corona PE film layer. An anthocyanin indicating film layer and a hot-melt pressure-sensitive adhesive layer are arranged on the two sides of the heat-sealing PE film layer respectively, a corona PE film layer and a heat-sealing PE film layer are arranged on the two sides of the hot-melt pressure-sensitive adhesive layer respectively, the area of the hot-melt pressure-sensitive adhesive layer is equal to that of the heat-sealing PE film layer, and the area of the anthocyanin indicating film layer is smaller than that of the heat-sealing PE film layer. The packaging composite film has the advantages that the heat-sealing PE film layer is attached to the corona PE film layer through the hot-melt pressure-sensitive adhesive, the composite film can be torn off from a container after the container is sealed in a heat-sealing mode, and the composite film can be adhered to the container again by means of the viscosity of the hot-melt pressure-sensitive adhesive layer after being torn off.

Description

Technical Field

[0001] The utility model relates to the field of packaging composite films, in particular to a packaging composite film for displaying the freshness of pork. Background Art

[0002] At present, monitoring technologies have also been widely applied in the food industry. By monitoring the freshness of pork in real time, the quality and safety of pork can be effectively guaranteed. In order to monitor the freshness of pork, a plastic wrap for monitoring the freshness of pork is disclosed in the patent publication document CN109016746A. This plastic wrap structure consists of four layers: a contact layer, a conduction layer, a water-absorbing and color-developing layer, and a moisture-retaining layer. However, when this plastic wrap structure is used in combination with a container, the contact layer itself is used for heat-sealing and cooperating with the edge of the container. When the plastic wrap is opened after the first heat-sealing, the contact layer will be damaged. Once the contact layer is damaged, the whole plastic wrap cannot seal the container again, nor can it display the freshness of the pork. Summary of the Utility Model

[0003] Aiming at the above problems, the utility model provides a packaging composite film for displaying the freshness of pork. By attaching a heat-sealing PE film layer to a corona-treated PE film layer using a hot-melt pressure-sensitive adhesive, after the container is sealed by heat-sealing, the composite film can be torn off from the container, and after tearing off, it can be re-bonded to the container again by the viscosity of the hot-melt pressure-sensitive adhesive layer.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A packaging composite film for displaying the freshness of pork includes a surface protective film layer, a corona-treated PE film layer, a hot-melt pressure-sensitive adhesive layer, a heat-sealing PE film layer, and an anthocyanin indicator film layer. The surface protective film layer and the hot-melt pressure-sensitive adhesive layer are respectively arranged on both sides of the corona-treated PE film layer. The anthocyanin indicator film layer and the hot-melt pressure-sensitive adhesive layer are respectively arranged on both sides of the heat-sealing PE film layer. The hot-melt pressure-sensitive adhesive layer is located between the corona-treated PE film layer and the heat-sealing PE film layer on both sides, and the area of the hot-melt pressure-sensitive adhesive layer is equal to the area of the heat-sealing PE film layer. The area of the anthocyanin indicator film layer is smaller than the area of the heat-sealing PE film layer.

[0006] In this packaging composite film, the anthocyanin indicator film layer functions to contact the pork and sense the change in the pH value of the pork because the pH value of the pork changes as it deteriorates.

[0007] The usage method of this specific packaging composite film is as follows. First, place the pork in a corresponding container, and then cover and seal the container with this packaging composite film by heat-sealing. Since the area of the anthocyanin indicator film layer is smaller than that of the heat-sealed PE film layer, a part of the heat-sealed PE film layer is in an exposed state. This exposed part of the heat-sealed PE film layer is thermally bonded to the wall surface of the container, and the anthocyanin indicator film layer is located inside the container, thus achieving the sealing and covering of the container. When it is necessary to tear off this packaging composite film from the container, this composite film can be directly torn off from the container. Since only a part of the heat-sealed PE film layer in this composite film is thermally bonded to the container, when this composite film is torn off from the container, the heat-sealed PE film layer will break. A part of the heat-sealed PE film layer still remains in the hot melt pressure-sensitive adhesive layer to form a residual part, while another part of the heat-sealed PE film layer adheres to the wall surface of the container to form an attachment part. Since a part of the heat-sealed PE film layer falls off from the hot melt pressure-sensitive adhesive layer, and since the area of the hot melt pressure-sensitive adhesive layer is equal to that of the heat-sealed PE film layer, a part of the hot melt pressure-sensitive adhesive layer is in an exposed state. Therefore, when the torn composite film needs to be adhered to the container again, the exposed part of the hot melt pressure-sensitive adhesive layer will be bonded to this part of the heat-sealed PE film layer (i.e., the attachment part), thus achieving the re-closure of the container.

[0008] In summary, in this composite film, by attaching the heat-sealed PE film layer to the corona-treated PE film layer using a hot melt pressure-sensitive adhesive, the composite film can be torn off from the container after heat-sealing the container, and after tearing off, it can be re-bonded to the container again by means of the viscosity of the hot melt pressure-sensitive adhesive layer.

[0009] In this packaging composite film, the heat-sealed PE film layer, the pressure-sensitive hot melt adhesive layer, and the corona-treated PE film layer are formed by co-extrusion casting.

[0010] At the same time, in this packaging composite film, the heat-sealed PE film layer is composed of LDPE and mLLDPE resins, and the corona-treated PE film layer is composed of LDPE and LLDPE resins.

[0011] In this composite film, the anthocyanin indicator film can be an anthocyanin indicator film prepared by the method shown in the patent publication document CN117554363A.

[0012] Optionally, the surface protective film layer is a biaxially oriented nylon film layer.

[0013] Using a biaxially oriented nylon film layer as the surface protective film layer can ensure that the entire composite film has good barrier properties.

[0014] Optionally, the thickness of the surface protective film layer is 12um - 30um.

[0015] Optionally, the thickness of the corona-treated PE film layer is 5um - 35um.

[0016] Optionally, the thickness of the heat-sealing PE film layer is 5 um to 35 um.

[0017] Optionally, the thickness of the hot-melt pressure-sensitive adhesive layer is 20 um to 40 um.

[0018] Optionally, the thickness of the anthocyanin indicator film layer is less than that of the heat-sealing PE film layer.

[0019] Optionally, the thickness of the anthocyanin indicator film layer is less than that of the surface protection film layer.

[0020] The beneficial effects of the present utility model are as follows: By attaching the heat-sealing PE film layer to the corona PE film layer using a hot-melt pressure-sensitive adhesive, the composite film can be torn off from the container after heat-sealing to close the container, and after tearing off, it can be re-bonded to the container again by virtue of the adhesiveness of the hot-melt pressure-sensitive adhesive layer. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0022] Figure 1 It is a schematic diagram of the state when the packaging composite film showing the freshness of pork closes the container;

[0023] Figure 2 It is a schematic diagram of the state when the packaging composite film showing the freshness of pork is torn off from the container.

[0024] In the figure, each reference numeral is: 1, surface protection film layer; 2, corona PE film layer; 3, hot-melt pressure-sensitive adhesive layer; 4, heat-sealing PE film layer; 41, residual part; 42, attachment part; 5, anthocyanin indicator film layer; 6, container. Detailed Embodiments

[0025] In order to make the above-mentioned objects, features, and advantages of the present utility model more obvious and understandable, the following will make a detailed description of the specific embodiments of the present utility model in conjunction with the drawings.

[0026] In the following description, many specific details are set forth in order to fully understand the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Those skilled in the art can make similar promotions without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0027] In the description of the present application, it should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present application. For the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0028] As shown in the attached Figure 1 and the attached Figure 2 figures, a packaging composite film for displaying the freshness of pork includes a surface protective film layer 1, a corona PE film layer 2, a hot melt pressure-sensitive adhesive layer 3, a heat-sealing PE film layer 4, and an anthocyanin indicator film layer 5. The surface protective film layer 1 and the hot melt pressure-sensitive adhesive layer 3 are respectively disposed on both sides of the corona PE film layer 2. The anthocyanin indicator film layer 5 and the hot melt pressure-sensitive adhesive layer 3 are respectively disposed on both sides of the heat-sealing PE film layer 4. The hot melt pressure-sensitive adhesive layer 3 is located between the corona PE film layer 2 and the heat-sealing PE film layer 4 on both sides. The area of the hot melt pressure-sensitive adhesive layer 3 is equal to the area of the heat-sealing PE film layer 4, and the area of the anthocyanin indicator film layer 5 is smaller than the area of the heat-sealing PE film layer 4.

[0029] In this packaging composite film, the anthocyanin indicator film layer 5 functions to contact the pork and sense the change in the pH value of the pork because the pH value of the pork changes as well.

[0030] Specifically, the usage method of this packaging composite film is as follows. First, place the pork in a corresponding container 6, and then seal and cover this packaging composite film on the container 6 by heat-sealing. Since the area of the anthocyanin indicator film layer 5 is smaller than the area of the heat-sealing PE film layer 4, a part of the heat-sealing PE film layer 4 is in a bare state. This part of the bare heat-sealing PE film layer 4 is thermally bonded to the wall surface of the container 6, and the anthocyanin indicator film layer 5 is located inside the container 6, thus achieving the sealing and capping of the container 6 (the state at this time is as shown in the attached Figure 1As shown in the figure). When it is necessary to tear off this kind of packaging composite film from the container 6, this kind of composite film can be directly torn off from the container 6. Since only a part of the heat-sealing PE film layer 4 in this kind of composite film is thermally bonded to the container 6 (the specific container 6 can be an ordinary plastic box), when this kind of composite film is torn off from the container 6, the heat-sealing PE film layer 4 will break. A part of the heat-sealing PE film layer 4 still remains on the hot-melt pressure-sensitive adhesive layer 3 to form a residual part 41, while another part of the heat-sealing PE film layer 4 adheres to the wall surface of the container 6 to form an attachment part 42. Since a part of the heat-sealing PE film layer 4 falls off from the hot-melt pressure-sensitive adhesive layer 3, and since the area of the hot-melt pressure-sensitive adhesive layer 3 is equal to the area of the heat-sealing PE film layer 4, a part of the hot-melt pressure-sensitive adhesive layer 3 is in an exposed state (the state at this time is as shown in the attached Figure 2 figure), so when the torn composite film needs to be adhered to the container 6 again, the exposed part of the hot-melt pressure-sensitive adhesive layer 3 will be adhered to this part of the heat-sealing PE film layer 4 (i.e., the attachment part 42), thus forming a re-closure of the container 6.

[0031] In summary, in this kind of composite film, by attaching the heat-sealing PE film layer 4 to the corona-treated PE film layer 2 using a hot-melt pressure-sensitive adhesive, the composite film can be torn off from the container 6 after heat-sealing the container 6, and after tearing off, it can be re-adhered to the container 6 again by means of the viscosity of the hot-melt pressure-sensitive adhesive layer 3.

[0032] In this kind of packaging composite film, the heat-sealing PE film layer 4, the pressure-sensitive hot-melt adhesive layer, and the corona-treated PE film layer 2 are formed by co-extrusion casting.

[0033] At the same time, in this kind of packaging composite film, the heat-sealing PE film layer is composed of LDPE and mLLDPE resins, and the corona-treated PE film layer is composed of LDPE and LLDPE resins.

[0034] In this kind of composite film, the anthocyanin indicator film can be an anthocyanin indicator film prepared by the method shown in the patent publication document CN117554363A.

[0035] As shown in the attached Figure 1 and attached Figure 2 figure, the surface protective film layer 1 is a biaxially oriented nylon film layer.

[0036] Using a biaxially oriented nylon film layer for the surface protective film layer 1 can ensure that the entire composite film has good barrier properties.

[0037] As shown in the attached Figure 1 and attached Figure 2 figure, the thickness of the surface protective film layer 1 is 12um to 30um.

[0038] As shown in the attached Figure 1 and attached Figure 2 figure, the thickness of the corona-treated PE film layer 2 is 5um to 35um.

[0039] As shown in the attached Figure 1 and the attached Figure 2 As shown, the thickness of the heat-sealing PE film layer 4 is 5 um to 35 um.

[0040] As shown in the attached Figure 1 and the attached Figure 2 As shown, the thickness of the hot-melt pressure-sensitive adhesive layer 3 is 20 um to 40 um.

[0041] As shown in the attached Figure 1 and the attached Figure 2 As shown, the thickness of the anthocyanin indicator film layer 5 is less than the thickness of the heat-sealing PE film layer 4.

[0042] As shown in the attached Figure 1 and the attached Figure 2 As shown, the thickness of the anthocyanin indicator film layer 5 is less than the thickness of the surface protective film layer 1.

[0043] The above-described embodiments only represent some embodiments of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention patent. It should be noted that for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A packaging composite film for displaying the freshness of pork, characterized in that, It includes a surface protective film layer, a corona-treated PE film layer, a hot-melt pressure-sensitive adhesive layer, a heat-sealing PE film layer, and an anthocyanin indicator film layer. The surface protective film layer and the hot-melt pressure-sensitive adhesive layer are respectively disposed on both sides of the corona-treated PE film layer. The anthocyanin indicator film layer and the hot-melt pressure-sensitive adhesive layer are respectively disposed on both sides of the heat-sealing PE film layer. The hot-melt pressure-sensitive adhesive layer is located between the corona-treated PE film layer and the heat-sealing PE film layer on both sides, and the area of the hot-melt pressure-sensitive adhesive layer is equal to that of the heat-sealing PE film layer. The area of the anthocyanin indicator film layer is smaller than that of the heat-sealing PE film layer.

2. The packaging composite film for displaying the freshness of pork according to claim 1, characterized in that, The surface protective film layer is a biaxially oriented nylon film layer.

3. A packaging composite film for displaying the freshness of pork according to claim 1, characterized in that, The thickness of the surface protective film layer is 12um to 30um.

4. The packaging composite film for displaying the freshness of pork according to claim 1, wherein, The thickness of the corona-treated PE film layer is 5um to 35um.

5. A packaging composite film for displaying the freshness of pork according to claim 1, characterized in that, The thickness of the heat-sealing PE film layer is 5um to 35um.

6. The packaging composite film for displaying the freshness of pork according to claim 1, wherein The thickness of the hot-melt pressure-sensitive adhesive layer is 20um to 40um.

7. A packaging composite film for displaying the freshness of pork according to claim 1, characterized in that, The thickness of the anthocyanin indicator film layer is smaller than that of the heat-sealing PE film layer.

8. A packaging composite film for displaying the freshness of pork according to claim 1, characterized in that, The thickness of the anthocyanin indicator film layer is smaller than that of the surface protective film layer.

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