Environment-friendly degradable heat shrink film

Abstract

The utility model belongs to the technical field of thermal shrinkage films, and particularly relates to an environment-friendly degradable thermal shrinkage film which comprises a thermal shrinkage film body, the thermal shrinkage film body is composed of a base layer, reinforcing layers, a blocking layer and a smooth layer, the reinforcing layers are arranged on the upper surface and the lower surface of the base layer, the blocking layer is arranged on one side of the reinforcing layers, and the smooth layer is arranged on the other side of the reinforcing layers. The smooth layer covers the outermost layer of the heat shrinkage film body and covers the outer side of the blocking layer, and the base layer, the reinforcing layer, the blocking layer and the smooth layer are bonded through an environment-friendly waterborne polyurethane adhesive. The biological organic fertilizer has high degradability and can be quickly decomposed in a natural environment or a composting condition, so that the environmental pollution is reduced; meanwhile, the film has excellent tensile resistance, tear resistance, barrier property and smoothness, and can be widely applied to packaging in various fields such as food, daily necessities and electronic products.

Description

Technical Field

[0001] This utility model belongs to the field of heat shrink film technology, specifically relating to an environmentally friendly biodegradable heat shrink film. Background Technology

[0002] Heat shrink film is widely used in product packaging. It tightly wraps goods, providing multiple functions such as moisture protection, dust protection, damage prevention, and enhancing the product's appearance. However, traditional heat shrink films, such as polyvinyl chloride (PVC) heat shrink film, are mostly non-biodegradable. After extensive use, discarded heat shrink film remains in the natural environment for a long time, causing serious pollution and damage to the soil, water bodies, and other ecological environments. This runs counter to the current global advocacy of environmental protection and sustainable development strategies. Therefore, developing a biodegradable and high-performance environmentally friendly heat shrink film is of great practical significance. Utility Model Content

[0003] To address the problems mentioned in the background section, this invention provides an environmentally friendly biodegradable heat shrink film, comprising a heat shrink film body, which is composed of a base layer, a reinforcing layer, a barrier layer, and a slip layer. The reinforcing layer is disposed on the upper and lower surfaces of the base layer, and the base layer, reinforcing layer, barrier layer, and slip layer are bonded together by an environmentally friendly water-based polyurethane adhesive.

[0004] As a preferred embodiment of the environmentally friendly biodegradable heat shrink film of this utility model, the base layer is made of a biodegradable polylactic acid and polybutylene succinate blend material, wherein the polylactic acid has good transparency and mechanical properties, and the thickness of the base layer is set to 15-35μm.

[0005] As a preferred embodiment of the environmentally friendly biodegradable heat shrinkable film of this utility model, the reinforcing layer is respectively disposed on the upper and lower surfaces of the base layer. The reinforcing layer is made of polyhydroxyalkanoate with added nano-cellulose whiskers. The thickness of the reinforcing layer is set to 3-10 μm, and it is uniformly dispersed in the polyhydroxyalkanoate.

[0006] As a preferred embodiment of the environmentally friendly biodegradable heat shrink film of this utility model, the barrier layer is disposed on one side of the reinforcing layer, the barrier layer is composed of a composite film material of polyvinyl alcohol and natural starch, and the thickness of the barrier layer is 5-12μm.

[0007] As a preferred embodiment of the environmentally friendly biodegradable heat shrink film of this utility model, the slip layer covers the outermost layer of the heat shrink film body and the slip layer covers the outside of the barrier layer.

[0008] As a preferred embodiment of the environmentally friendly biodegradable heat shrink film of this utility model, the slip layer is made of biodegradable polyester material with added erucamide, and the thickness of the slip layer is set to 1-4 μm.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] High biodegradability: It uses a variety of biodegradable materials, which can decompose quickly in the natural environment or under composting conditions, reducing long-term pollution to the environment and meeting environmental protection requirements;

[0011] Excellent physical properties: The synergistic effect of the base layer, reinforcing layer, barrier layer and slip layer gives the heat shrink film good tensile strength, tear resistance, barrier and slip properties, which can meet the packaging needs of a variety of products and effectively protect the products during packaging, transportation and storage.

[0012] Wide applicability: It can be used for packaging in many fields such as food, daily necessities, and electronic products. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0014] Figure 1 is an internal layer diagram of an environmentally friendly biodegradable heat shrink film of this utility model;

[0015] In the picture:

[0016] 11. Heat shrinkable film body; 12. Base layer; 13. Reinforcing layer; 14. Barrier layer; 15. Slip layer. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0018] like Figure 1 As shown;

[0019] An environmentally friendly biodegradable heat shrink film includes a heat shrink film body 1.

[0020] This implementation plan addresses the technical problems existing in the prior art, such as the aforementioned background technology disclosure: "Heat shrink film is widely used in commodity packaging. It can tightly wrap goods, playing multiple roles such as moisture protection, dust protection, damage prevention, and beautifying the appearance of goods. However, traditional heat shrink films, such as polyvinyl chloride (PVC) heat shrink film, are mostly non-degradable. After extensive use, the discarded heat shrink film will remain in the natural environment for a long time, causing serious pollution and damage to the ecological environment such as soil and water bodies. This runs counter to the current global advocacy of environmental protection concepts and sustainable development strategies." In terms of practical use, this problem is obviously a real and difficult-to-solve issue. Therefore, to solve this technical problem, an environmentally friendly biodegradable heat shrink film is provided.

[0021] As shown in Figure 1; in conjunction with the above, the heat shrinkable film body 1 is composed of a base layer 11, a reinforcing layer 12, a barrier layer 13 and a slip layer 14. The reinforcing layer 12 is disposed on the upper and lower surfaces of the base layer 11. The base layer 11, the reinforcing layer 12, the barrier layer 13 and the slip layer 14 are bonded together by an environmentally friendly water-based polyurethane adhesive.

[0022] In an optional embodiment, the base layer 11 is made of a biodegradable blend of polylactic acid (PLA) and polybutylene succinate (PBS). PLA possesses good transparency and mechanical properties, while PBS imparts better toughness and processability. The thickness of the base layer 11 is 15-35 μm. By adjusting the blending ratio of the two materials, the overall performance of the base layer can be optimized, ensuring it meets the basic physical requirements of heat-shrinkable film while also exhibiting good biodegradability.

[0023] In an optional embodiment, the reinforcing layer 12 is disposed on both the upper and lower surfaces of the base layer 11. The reinforcing layer 12 is made of polyhydroxyalkanoate (PHA) with added nanocellulose whiskers. The nanocellulose whiskers possess extremely high strength and modulus, significantly enhancing the tensile and tear resistance of the heat-shrinkable film. The thickness of the reinforcing layer 12 is 3-10 μm. It is uniformly dispersed in the PHA, forming a high-strength composite structure that effectively improves the overall mechanical properties of the heat-shrinkable film.

[0024] In an optional embodiment, the barrier layer 13 is disposed on one side of the reinforcing layer 12 (i.e., the outer surface of the reinforcing layer on one side of the base layer). The barrier layer 13 is composed of a composite film material of polyvinyl alcohol (PVA) and natural starch. Polyvinyl alcohol has good properties for blocking oxygen and moisture, while natural starch further improves the biodegradability of the material and reduces costs. The thickness of the barrier layer 13 is 5-12 μm. This barrier layer can effectively prevent oxygen, moisture, and other substances in the external environment from corroding the packaged goods, extending the shelf life and freshness of the goods.

[0025] In an optional embodiment, the slip layer 14 covers the outermost layer of the heat shrink film body 1 and the outside of the barrier layer 13. The slip layer 14 is made of a biodegradable polyester material with added erucamide. Erucamide can reduce the coefficient of friction of the heat shrink film surface, giving the heat shrink film good slip properties during packaging, facilitating the operation of automated packaging equipment. The thickness of the slip layer 14 is 1-4 μm.

[0026] The preparation method of this utility model is as follows: First, polylactic acid and polybutylene succinate are thoroughly mixed in a high-speed mixer according to a predetermined ratio, and then added to a twin-screw extruder for melt extrusion to form a base film. Next, nano-cellulose whiskers are uniformly dispersed in a polyhydroxyalkanoate solution, and after drying and granulation, they are co-extruded onto the upper and lower surfaces of the base layer to form a reinforcing layer. Then, polyvinyl alcohol and natural starch are uniformly mixed in a specific solvent system to prepare a barrier layer material, which is then co-extruded or laminated onto the outer surface of one side of the reinforcing layer. Finally, erucamide and biodegradable polyester material are mixed and extruded to form a slip layer on the outside of the barrier layer. During the composite process of each layer, a water-based polyurethane adhesive is used to ensure the bonding strength between the layers.

[0027] Finally, it should be noted that the above are merely preferred embodiments of this utility model and are not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An environmentally friendly biodegradable heat shrink film, comprising a heat shrink film body (1), characterized in that: The heat shrinkable film body (1) is composed of a base layer (11), a reinforcing layer (12), a barrier layer (13) and a slip layer (14). The reinforcing layer (12) is disposed on the upper and lower surfaces of the base layer (11). The base layer (11), the reinforcing layer (12), the barrier layer (13) and the slip layer (14) are bonded together by an environmentally friendly water-based polyurethane adhesive.

2. The environmentally friendly biodegradable heat-shrinkable film according to claim 1, characterized in that: The thickness of the base layer (11) is set to 15-35 μm.

3. The environmentally friendly biodegradable heat-shrinkable film according to claim 1, characterized in that: The reinforcing layer (12) is respectively disposed on the upper and lower surfaces of the base layer (11), and the thickness of the reinforcing layer (12) is 3-10 μm.

4. The environmentally friendly biodegradable heat-shrinkable film according to claim 1, characterized in that: The barrier layer (13) is disposed on one side of the reinforcement layer (12), and the thickness of the barrier layer (13) is 5-12 μm.

5. The environmentally friendly biodegradable heat-shrinkable film according to claim 1, characterized in that: The slip layer (14) covers the outermost layer of the heat shrink film body (1) and the slip layer (14) covers the outside of the barrier layer (13).

6. The environmentally friendly biodegradable heat-shrinkable film according to claim 1, characterized in that: The thickness of the slip layer (14) is set to 1-4 μm.

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