Biodegradable heat-shrinkable packaging film for cigarette packaging and transportation

Abstract

The embodiment of the utility model provides a biodegradable heat-shrinkable packaging film for cigarette packaging and transportation, and the biodegradable heat-shrinkable packaging film for cigarette packaging and transportation comprises a base material layer which is made of a biodegradable material; a high friction layer; wherein the high friction layer and the base material layer are laminated. The base material layer in the heat shrinkage packaging film is made of the biodegradable material, so that the influence on the environment is reduced, and the plastic garbage is reduced. The high-friction layer is introduced into the thermal shrinkage film, so that the problem that the surface of the base material layer is smooth is solved. And the surface of the thermal shrinkage film becomes rougher, so that the surface of a packaged product has higher roughness and road holding force, and the stacking stability is improved. In other words, the products can be stacked more easily and stably during stacking, and unstable factors caused by sliding of the products are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of packaging films, and in particular to a biodegradable heat shrinkable packaging film for cigarette packaging and transportation. Background Art

[0002] Heat shrink film is a common heat shrinkable plastic film, mainly made of polyethylene (PE), polyethylene-polypropylene blend (POF), thermoplastic polyester (PET) and other raw materials. Its remarkable features are simple packaging process and excellent sealing performance. It can be widely used in the outer packaging of food, medicine, sterilized tableware, stationery, craft gifts, printed materials, hardware and plastic products, telephones, electronic equipment and other products.

[0003] Heat shrink films are divided into biodegradable heat shrink films and non-degradable heat shrink films. Current biodegradable heat shrink films are usually made of materials such as polylactic acid. These films have smooth and soft surfaces, which may cause instability during the stacking process after product packaging. This surface characteristic is not conducive to forming stable packaging stacking, and may cause the packaged product to tilt, slide or collapse, causing inconvenience in storage and transportation, and may even damage the product.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Utility Model Content

[0005] The embodiments of the present application provide a biodegradable heat-shrinkable packaging film for cigarette packaging and transportation to solve or alleviate one or more of the technical problems mentioned above.

[0006] As one aspect of an embodiment of the present application, the embodiment of the present application provides a biodegradable heat shrinkable packaging film for cigarette packaging and transportation, comprising:

[0007] a substrate layer made of a biodegradable material;

[0008] High friction layer;

[0009] Wherein, the high friction layer is stacked with the substrate layer.

[0010] Optionally, the biodegradable heat-shrinkable packaging film for cigarette packaging and transportation further comprises:

[0011] A low friction layer, stacked with the substrate layer; the substrate layer comprises a first surface and a second surface opposite to each other;

[0012] Wherein, the low friction layer is located on the first surface of the substrate layer, and the high friction layer is located on the second surface of the substrate layer; the surface friction force of the low friction layer is smaller than the surface friction force of the high friction layer.

[0013] Optionally, the biodegradable heat-shrinkable packaging film for cigarette packaging and transportation further comprises:

[0014] The first adhesive layer is laminated between the high friction layer and the base material layer.

[0015] Optionally, the thickness of the first adhesive layer is 0.5-3 μm.

[0016] Optionally, the biodegradable heat-shrinkable packaging film for cigarette packaging and transportation further comprises:

[0017] A low friction layer, stacked with the substrate layer; the substrate layer comprises a first surface and a second surface opposite to each other;

[0018] Wherein, the low friction layer is located on the first surface of the substrate layer, and the high friction layer is located on the second surface of the substrate layer; the surface friction force of the low friction layer is smaller than the surface friction force of the high friction layer.

[0019] Optionally, the low friction layer has a thickness of 1-5 μm.

[0020] Optionally, the biodegradable heat-shrinkable packaging film for cigarette packaging and transportation further comprises:

[0021] The second adhesive layer is laminated between the low friction layer and the base material layer.

[0022] Optionally, the second adhesive layer has a thickness of 0.5-3 μm.

[0023] Optionally, the substrate layer has a thickness of 10-50 μm.

[0024] Optionally, the high friction layer has a thickness of 1-5 μm.

[0025] The above technical solution adopted in the embodiment of the present application may have the following advantages: a substrate layer and a high friction layer are adopted. Among them:

[0026] The substrate layer is made of biodegradable material, which reduces the impact on the environment and reduces plastic waste.

[0027] The introduction of a high friction layer in the heat shrink film overcomes the problem of the smooth surface of the substrate layer. The surface of the heat shrink film becomes rougher, which makes the surface of the packaged product more rough and grippy, and improves the stability of the stacking. That is, the product is easier to stack stably when stacking, reducing the instability caused by product sliding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0029] Figure 1 It is a schematic diagram of the structure of a biodegradable heat shrinkable packaging film for cigarette packaging and transportation provided in an embodiment of the present application.

[0030] Figure 2 This is another schematic diagram of the structure of the biodegradable heat shrinkable packaging film for cigarette packaging and transportation provided in an embodiment of the present application.

[0031] Figure 3 This is another schematic diagram of the structure of the biodegradable heat shrinkable packaging film for cigarette packaging and transportation provided in an embodiment of the present application.

[0032] Figure 4 This is another schematic diagram of the structure of the biodegradable heat shrinkable packaging film for cigarette packaging and transportation provided in an embodiment of the present application.

[0033] Description of reference numerals:

[0034] 1. Base material layer

[0035] 2 High friction layer

[0036] 3. First adhesive layer

[0037] 4 Low friction layer

[0038] 5. Second adhesive layer DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] To facilitate those skilled in the art to understand the technical solutions provided in the embodiments of the present application, the relevant technologies are described below:

[0042] Heat shrink film is a type of heat-shrinkable plastic film, mainly made of polyethylene (PE), polyethylene-polypropylene blend (POF), thermoplastic polyester (PET), etc. It has a simple packaging process and excellent sealing performance, and can be widely used in the outer packaging of food, medicine, sterilized tableware, stationery, craft gifts, printed materials, hardware and plastic products, telephones, electronic appliances and other products.

[0043] Heat shrink films are divided into non-biodegradable heat shrink films and biodegradable heat shrink films. Non-biodegradable heat shrink films are difficult to degrade and recycle, and are prone to environmental pollution. Although biodegradable thin heat shrink films are highly environmentally friendly, they are made of materials such as polylactic acid, and the film surface is smooth and soft, which may cause instability during the stacking process after product packaging. This surface characteristic is not conducive to forming a stable packaging stack, and may cause the packaged product to tilt, slide or collapse, causing inconvenience in storage and transportation, and may even damage the product.

[0044] To this end, the embodiment of the present application provides a biodegradable heat-shrinkable packaging film for cigarette packaging and transportation: it is composed of a substrate layer, a high friction layer, a first adhesive layer, a low friction layer and a second adhesive layer. Among them, the substrate layer is made of biodegradable material, has the property of shrinking when heated, and is highly environmentally friendly. The high friction layer can be used to increase the surface friction of the heat shrinkable film, overcome the problem of the smooth surface of the substrate layer, make the surface of the packaged product rougher and more grippy, and improve the stability of the stacking. The first adhesive layer can be used to increase the interfacial bonding strength between the substrate layer and the high friction layer. The low friction layer can be used to reduce the friction between the heat shrinkable film and the product, protecting the product while improving the packaging performance. The second adhesive layer can be used to increase the interfacial bonding strength between the substrate layer and the friction layer. See below for details.

[0045] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0046] like Figure 1 As shown, the biodegradable heat-shrinkable packaging film for cigarette packaging and transportation may include: a substrate layer 1 and a high friction layer 2 .

[0047] The respective structures and matching relationship of the substrate layer 1 and the high friction layer 2 are introduced below.

[0048] The substrate layer 1 can be used to carry other structural layers (such as the high friction layer 2) and bear the main mechanical function, and has the property of shrinking when heated. The substrate layer 1 can be made of various conventional biodegradable materials, for example, it can be prepared by one or more biodegradable polyester resins such as polylactic acid resin, polybutylene terephthalate-adipate resin, polyhydroxyalkanoate resin, polybutylene succinate resin, etc. Since it can be biodegraded, it can reduce pollution to the environment and reduce plastic waste.

[0049] The high friction layer 2 can be laminated on the surface of the substrate layer 1 to make the surface of the heat shrinkable film rough. The surface friction of the high friction layer 2 is greater than the surface friction of the substrate layer 1. The high friction layer 2 can be made of polylactic acid resin containing fillers, and the surface properties of the polylactic acid resin are changed by the fillers, so that the surface of the high friction layer is uneven and rough. Since it is made of polylactic acid resin, the high friction layer 2 can also be biodegradable, reducing environmental pollution.

[0050] In this embodiment, by laminating the high friction layer 2 on the surface of the substrate layer 1, the surface friction of the heat shrink film can be increased, so that the surface of the product packaged by the heat shrink film has more roughness and grip, and the stability of the stacking is improved. That is, the products are easier to stack stably when stacking, and the instability factor caused by product sliding is reduced.

[0051] The above embodiment introduces how to improve the performance of the heat shrink film by stacking the substrate layer 1 and the high friction layer 2. In fact, by optimizing the design of the substrate layer 1 and the high friction layer 2, the performance level of the heat shrink film can be further improved. For example:

[0052] In an optional embodiment, the thickness of the substrate layer 1 may be 10-50 μm. If the thickness of the substrate layer 1 is too large, the packaged product will be difficult to unpack and the user experience will be reduced. If the thickness of the substrate layer 1 is too small, the strength of the heat shrink film will be low, it will be easy to break, and it will be unfavorable for product packaging and transportation.

[0053] In an optional embodiment, the thickness of the high friction layer 2 may be 1-5 μm, and may further preferably be 2-3 μm. If the high friction layer 2 is too thick, it may cause the high friction layer 2 to accumulate and break during packaging. If the high friction layer 2 is too thin, it may not play a role in increasing the friction force on the surface of the heat shrink film.

[0054] It should be noted that the thickness of the substrate layer 1 and the high friction layer 2 can be determined according to actual application scenarios and business requirements.

[0055] The above embodiment introduces a heat shrinkable film composed of a substrate layer 1 and a high friction layer 2. In order to further improve the performance of the heat shrinkable film, more structural layers can be provided for the heat shrinkable film. Several exemplary schemes will be provided below.

[0056] In an optional embodiment, if Figure 3 As shown, the biodegradable heat shrink packaging film for cigarette packaging and transportation may also include a low friction layer 4 laminated with the substrate layer 1. Wherein, the substrate layer 1 includes two opposite surfaces: a first surface and a second surface. The low friction layer 4 can be laminated on the first surface of the substrate layer 1, and the high friction layer 2 can be laminated on the second surface of the substrate layer 1. The surface friction of the low friction layer 4 is less than the surface friction of the high friction layer 2. In the actual packaging application of the heat shrink film, the high friction layer 4 faces the outside to overcome the problem of the product surface being too smooth after packaging. Accordingly, the low friction layer 4 faces the product, which can reduce the friction between the heat shrink film and the product, improve the degree of fit between the heat shrink film and the product during the shrink packaging process, and better protect the product while improving the packaging performance. The low friction layer 4 can be made of high-crystallinity polylactic acid resin, which can be biodegradable and reduce environmental pollution.

[0057] In this embodiment, the low friction layer 4 is introduced into the heat shrinkable film, which can effectively improve the packaging performance of the heat shrinkable film.

[0058] In fact, the performance level of the heat shrinkable film can be further improved by optimizing the design of the low friction layer 4. For example:

[0059] In an optional embodiment, the thickness of the low friction layer 4 may be 1-5 μm. If the thickness of the low friction layer 4 is too large, the low friction layer 4 may be piled up and broken during packaging. If the thickness of the low friction layer 4 is too small, it may not play a role in reducing friction.

[0060] It should be noted that the thickness of the low friction layer 4 can be determined according to actual application scenarios and business requirements.

[0061] After laminating the substrate layer 1, the high friction layer 2 and the low friction layer 4, further optimization design may be performed to improve the overall structural stability and performance of the heat shrinkable film. Several exemplary solutions are provided below.

[0062] In an optional embodiment, if Figure 2 As shown, the biodegradable heat shrinkable packaging film for cigarette packaging and transportation may also include a first adhesive layer 3, which may be laminated between the high friction layer 2 and the substrate layer 1. The first adhesive layer 3 has an adhesive ability, which can improve the interfacial bonding strength between the high friction layer 2 and the substrate layer 1, thereby optimizing the stability of the heat shrinkable film. The first adhesive layer 3 may be made of biodegradable resins such as polylactic acid resin, polybutylene terephthalate-adipate resin, polyhydroxyalkanoate resin, polybutylene succinate resin, etc. and a crosslinking agent, and has biodegradability.

[0063] In this embodiment, by adding the first adhesive layer 3 between the high friction layer 2 and the substrate layer 1 , the structural stability of the heat shrinkable film can be effectively improved.

[0064] In an optional embodiment, the thickness of the first adhesive layer 3 may be 0.5-3 μm, and more preferably 1-2 μm. If the first adhesive layer 3 is too thick or too thin, the peeling strength will be reduced, which will affect the bonding effect.

[0065] In an optional embodiment, if Figure 4 As shown, the biodegradable heat shrinkable packaging film for cigarette packaging and transportation may also include a second adhesive layer 5, which may be laminated between the low friction layer 4 and the substrate layer 1. The second adhesive layer 5 has an adhesive ability, which can improve the interfacial bonding strength between the low friction layer 4 and the substrate layer 1, and further optimize the stability of the heat shrinkable film. The second adhesive layer 5 may be made of a biodegradable resin such as polylactic acid resin, polybutylene terephthalate-adipate resin, polyhydroxyalkanoate resin, polybutylene succinate resin, etc. and a crosslinking agent, and has biodegradability.

[0066] In this embodiment, by adding a second adhesive layer 5 between the low friction layer 4 and the base material layer 1 , the structural stability of the heat shrinkable film can be further improved.

[0067] In an optional embodiment, the thickness of the second adhesive layer 5 may be 0.5-3 μm, and more preferably 1-2 μm. If the second adhesive layer 5 is too thick or too thin, the peeling strength will be reduced, which will affect the bonding effect.

[0068] It should be noted that the thickness of the first adhesive layer 3 and the second adhesive layer 5 can be determined according to actual application scenarios and business requirements.

[0069] The biodegradable heat shrinkable film for cigarette packaging and transportation provided in the embodiments of the present application can be used in the field of product packaging and transportation, and can be prepared by extrusion, blow molding, casting, double bubble method, coating, etc. An exemplary preparation process is as follows:

[0070] S1: different extruders are used to melt raw materials of different structural layers to obtain molten materials.

[0071] S2: The molten materials of different structural layers are extruded into an annular mold through an extruder to form a multi-layer structure, and then blow-molded to obtain a smaller embryo tube.

[0072] S3: Inflate the embryo tube above the glass transition temperature and below the melting point of the embryo tube and rapidly cool it down to obtain a biodegradable heat shrinkable film.

[0073] The biodegradable heat shrink film for cigarette packaging and transportation provided in the embodiment of the present application overcomes the problem of the smooth surface of the substrate layer, and the surface becomes rougher, so that the surface of the packaged product has more roughness and grip, and the stability of the stacking is improved. That is, the products are easier to stack stably when stacked, and the instability factor caused by product sliding is reduced.

[0074] A plurality of biodegradable heat shrinkable films for cigarette packaging and transportation with different structures will be provided below to further illustrate the technical solutions of the embodiments of the present application.

[0075] Example 1

[0076] like Figure 1 As shown, a biodegradable heat shrinkable packaging film for cigarette packaging and transportation has the following structure:

[0077] Base material layer 1 and high friction layer 2.

[0078] The base layer 1 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 100 parts by weight of polybutylene terephthalate-adipate resin, and has a thickness of 30 μm.

[0079] The high friction layer 2 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 10 parts by weight of silicon dioxide with an average diameter of 2 μm.

[0080] Example 2

[0081] like Figure 2 As shown, a biodegradable heat shrinkable packaging film for cigarette packaging and transportation has the following structure:

[0082] Base material layer 1, high friction layer 2 and first adhesive layer 3.

[0083] The base material layer 1 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 100 parts by weight of polybutylene terephthalate adipate resin.

[0084] The high friction layer 2 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 10 parts by weight of silicon dioxide with an average diameter of 2 μm.

[0085] The first adhesive layer 3 is made of 100 parts by weight of polyhydroxybutyrate-hydroxycaproate resin and 1 part by weight of diisocyanate.

[0086] Example 3

[0087] like Figure 3 As shown, a biodegradable heat shrinkable packaging film for cigarette packaging and transportation has the following structure:

[0088] Base material layer 1, high friction layer 2 and low friction layer 4.

[0089] The base material layer 1 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 100 parts by weight of polybutylene terephthalate adipate resin.

[0090] The high friction layer 2 is made of 100 parts by weight of polylactic acid resin (96% of the synthetic monomer units are L-lactic acid) and 10 parts by weight of silicon dioxide with an average diameter of 2 μm.

[0091] The low friction layer 4 is made of 100 parts by weight of a polylactic acid resin (99% of the monomer units are L-lactic acid).

[0092] Example 4

[0093] like Figure 4 As shown, a biodegradable heat shrinkable packaging film for cigarette packaging and transportation has the following structure: a substrate layer 1, a high friction layer 2, a first adhesive layer 3, a low friction layer 4 and a second adhesive layer 5.

[0094] The base material layer 1 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 100 parts by weight of polybutylene terephthalate adipate resin.

[0095] The high friction layer 2 is made of 100 parts by weight of polylactic acid resin (96% of the monomer units are L-lactic acid) and 10 parts by weight of silicon dioxide with an average diameter of 2 μm.

[0096] The first adhesive layer 3 is made of 100 parts by weight of polyhydroxybutyrate-hydroxycaproate resin and 1 part by weight of diisocyanate.

[0097] The low friction layer 4 is made of 100 parts by weight of a polylactic acid resin (99% of the monomer units are L-lactic acid).

[0098] The second adhesive layer 5 is made of 100 parts by weight of polyhydroxybutyrate-hydroxycaproate resin and 1 part by weight of diisocyanate.

[0099] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0100] For the convenience of description, the orientation or position relationship indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, vertical, horizontal" and "top, bottom" is usually based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. Unless otherwise stated, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0101] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0102] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0103] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0104] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0105] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0106] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A biodegradable heat shrinkable packaging film for cigarette packaging and transportation, characterized in that: include: A substrate layer (1) made of a biodegradable material; High friction layer (2); Wherein, the high friction layer (2) is stacked with the substrate layer (1).

2. The heat shrinkable packaging film according to claim 1, characterized in that: Also includes: A low friction layer (4) stacked with the substrate layer (1); the substrate layer (1) comprises a first surface and a second surface opposite to each other; The low friction layer (4) is located on the first surface of the substrate layer (1), and the high friction layer is located on the second surface of the substrate layer (1); the surface friction force of the low friction layer (4) is smaller than the surface friction force of the high friction layer (2).

3. The heat shrink packaging film according to claim 1, characterized in that: Also includes: The first adhesive layer (3) is laminated between the high friction layer (2) and the substrate layer (1).

4. The heat shrink packaging film according to claim 3, characterized in that: The thickness of the first adhesive layer (3) is 0.5-3 μm.

5. The heat shrinkable packaging film according to claim 3, characterized in that: Also includes: A low friction layer (4) stacked with the substrate layer (1); the substrate layer (1) comprises a first surface and a second surface opposite to each other; The low friction layer (4) is located on the first surface of the substrate layer (1), and the high friction layer is located on the second surface of the substrate layer (1); the surface friction force of the low friction layer (4) is smaller than the surface friction force of the high friction layer (2).

6. The heat shrinkable packaging film according to claim 5, characterized in that: The low friction layer (4) has a thickness of 1-5 μm.

7. The heat shrinkable packaging film according to claim 5, characterized in that: Also includes: The second adhesive layer (5) is laminated between the low friction layer (4) and the base material layer (1).

8. The heat shrinkable packaging film according to claim 7, characterized in that: The thickness of the second adhesive layer (5) is 0.5-3 μm.

9. The heat shrinkable packaging film according to any one of claims 1 to 8, characterized in that: The thickness of the substrate layer (1) is 10-50 μm.

10. The heat shrinkable packaging film according to any one of claims 1 to 8, characterized in that: The thickness of the high friction layer (2) is 1-5 μm.

Images