High-flatness PVC shrink film
By designing a multi-layer composite structure and a hydrophobic nano-coating, the strength and flatness issues of PVC shrink film are solved, achieving improved flatness and hydrophobic performance, while also providing antibacterial and cushioning insulation functions.
Patent Information
- Application Number
- CN202423269817.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-28
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2034-12-28
AI Technical Summary
Existing PVC shrink film has low strength, is easily deformed, and lacks flatness, which affects its performance.
It adopts a multi-layer composite structure, including a PVC base film layer, a POF film layer, a chitin/gelatin composite film and a biaxially oriented polyester film, and is coated with a hydrophobic nano-coating, preferably a nano-TiO2/ZnO composite superhydrophobic coating.
It improves the smoothness and hydrophobicity of the shrink film, while also providing antibacterial and cushioning insulation effects.
Smart Images
Figure CN223934327U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a high-flatness PVC shrink film, belonging to the field of PVC shrink film technology. Background Technology
[0002] PVC, primarily composed of polyvinyl chloride, is a slightly yellowish, translucent, and glossy material, and is the main raw material for shrink film. Conventionally used PVC shrink film is prepared using a casting process. However, existing PVC films have a simple structure, low strength, and are easily deformed by stretching, affecting their performance and flatness, leading to localized defects during use. Therefore, developing a high-flatness PVC shrink film is a key problem to be solved. Utility Model Content
[0003] The purpose of this invention is to provide a high-flatness PVC shrink film. By combining multiple layers of shrink films made of different materials, the flatness of the film can be improved.
[0004] To solve the above-mentioned technical problems, the purpose of this utility model is achieved as follows:
[0005] The present invention relates to a high-flatness PVC shrink film, comprising a composite PVC base film layer, a POF film layer, and a chitin / gelatin composite film; a biaxially oriented polyester film is laminated on the side of the PVC base film layer away from the POF film layer; and a hydrophobic nano-coating is provided on the surface of the side of the biaxially oriented polyester film away from the PVC base film layer.
[0006] Based on the above scheme and as a preferred embodiment of the above scheme: the hydrophobic nano-coating is a nano-TiO2 / ZnO composite superhydrophobic coating.
[0007] Based on the above scheme and as a preferred embodiment of the above scheme: the PVC base film layer includes a first PVC casting layer, a polyethylene fiber mesh layer and a second PVC casting layer.
[0008] Based on the above scheme and as a preferred embodiment of the above scheme: a heat-insulating shrink film is provided between the PVC base film layer and the POF film layer.
[0009] Based on the above scheme and as a preferred embodiment of the above scheme: the heat insulation shrink film is a PVDC heat insulation shrink film.
[0010] The beneficial effects of this utility model are as follows: The high-flatness PVC shrink film involved in this utility model adopts a composite of a PVC base film layer, a POF film layer, a chitosan / gelatin composite film, and an axially stretched polyester film, which can improve the flatness of the shrink film. Furthermore, the chitosan / gelatin composite film used has antibacterial effects, and the applied hydrophobic nano-coating can improve the hydrophobic effect of the shrink film. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the high-flatness PVC shrink film involved in Example 1;
[0012] Figure 2 This is a schematic diagram of the structure of the PVC base film layer;
[0013] Figure 3 This is a schematic diagram of the high-flatness PVC shrinkage structure involved in Example 2.
[0014] The markings in the diagram are explained as follows: 1-PVC base film layer; 2-POF film layer; 3-Chitin / gelatin composite film; 4-Biaxially oriented polyester film; 5-Hydrophobic nano-coating; 6-Heat insulation shrink film; 11-First PVC casting layer; 12-Polyethylene fiber mesh layer; 13-Second PVC casting layer. Detailed Implementation
[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0016] Example 1
[0017] Combination Figure 1 and Figure 2 This embodiment provides a detailed description. The high-flatness PVC shrink film involved in this embodiment includes a composite PVC base film layer 1, a POF film layer 2, and a chitosan / gelatin composite film 3; a biaxially oriented polyester film 4 is laminated to the side of the PVC base film layer 1 away from the POF film layer 2; a hydrophobic nano-coating 5 is provided on the surface of the side of the biaxially oriented polyester film 4 away from the PVC base film layer 1. Single-layer PVC shrink film suffers from low flatness, but multi-layer film lamination improves its flatness, thus achieving a high-flatness shrink film.
[0018] Gelatin is a linear polypeptide polymer, a product of partial hydrolysis of collagen, containing 18 different amino acids and a partial triple helix structure. Due to the hydrolysis of collagen, the original triple helix structure is disrupted, producing functional groups such as amino, hydroxyl, and carboxyl groups. The presence of these groups generates polar interactions or interactions that attract opposite charges, leading to intermolecular van der Waals forces, electrostatic attraction, and hydrogen bonds, which facilitate molecular bonding. Gelatin contains a large number of hydrophilic amino acids, therefore it has a strong water absorption capacity, reaching 5 to 10 times its own weight. It swells after absorbing water. Gelatin gel has the reversible property of melting upon heating and gelling upon cooling, known as gelling property. The melting point of gelatin gel is close to its freezing point and lower than the normal physiological temperature of the human body, therefore it can be made into edible food packaging films. Chitosan is a biodegradable natural polymer widely found in the shells of crustaceans, the epidermis of various insects, the bone marrow of mollusks, and the cell walls of fungi and algae. Its molecular structure is a binary linear polymer composed of 2-acetamido-2-deoxy-D-pyranoglycosan and 2-amino-2-deoxy-D-pyranoglycosan linked by β-1,4 glycosidic bonds, and it possesses certain antiviral capabilities. A composite film is prepared by blending gelatin and chitosan using a casting method. This allows the shrink film to be suitable for food packaging.
[0019] The use of hydrophobic nano-coating 5 gives the shrink film good hydrophobic properties, enabling it to protect the packaged items when used as a packaging film.
[0020] Furthermore, the hydrophobic nano-coating 5 is a nano-TiO2 / ZnO composite superhydrophobic coating. The use of titanium dioxide gives the shrink film a UV protection effect, while the use of zinc oxide can improve its antibacterial properties.
[0021] Furthermore, the PVC base film layer 1 includes a first PVC cast layer 11, a polyethylene fiber web layer 12, and a second PVC cast layer 13. A polyethylene fiber web layer 12 is coated on the upper surface of the first PVC cast layer 11, followed by the second PVC cast layer 13, and then the layers are rolled together. The polyethylene fiber layer 12 has a fluffy texture, which gives the cast PVC shrink film prepared in this embodiment a cushioning and heat-insulating effect.
[0022] Example 2
[0023] Combination Figure 3This embodiment will be described in detail below. The high-flatness PVC shrink film involved in this embodiment differs from that in Embodiment 1 in that a heat-insulating shrink film 6 is disposed between the PVC base film layer 1 and the POF film layer 2. The heat-insulating shrink film 6 is a PVDC heat-insulating shrink film. The outer layer of the PVDC heat-insulating shrink film is a first PE layer, which is a mixture of UPE and ethylene-α-olefin copolymer; the outer adhesive layer is EVA resin, used to bond the first PE layer and the intermediate layer; the intermediate layer is composed of PVDC resin, epoxidized soybean oil, heat stabilizer, and lubricant; the inner adhesive layer is EVA resin, used to bond the second PE layer and the intermediate layer; the outer layer is the second PE layer, which is a mixture of LLDPE and MLLDPE.
[0024] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.
Claims
1. A high-flatness PVC shrink film, characterized in that, It includes a composite PVC base film layer (1), a POF film layer (2), and a chitin / gelatin composite film (3); the PVC base film layer (1) is coated with a biaxially oriented polyester film (4) on the side away from the POF film layer (2); the surface of the biaxially oriented polyester film (4) away from the PVC base film layer (1) is provided with a hydrophobic nano-coating (5).
2. The high-flatness PVC shrink film according to claim 1, characterized in that, The hydrophobic nano-coating (5) is a nano-TiO2 / ZnO composite superhydrophobic coating.
3. The high-flatness PVC shrink film according to claim 1, characterized in that, The PVC base film layer (1) includes a first PVC cast layer (11), a polyethylene fiber mesh layer (12), and a second PVC cast layer (13).
4. The high-flatness PVC shrink film according to claim 3, characterized in that, A heat-insulating shrink film (6) is provided between the PVC base film layer (1) and the POF film layer (2).
5. The high-flatness PVC shrink film according to claim 4, characterized in that, The heat-insulating shrink film (6) is a PVDC heat-insulating shrink film.