Casting PVC shrink film
The three-layer composite PVC shrink film solves the problems of insufficient antibacterial properties and easy damage in food packaging, achieving high-strength and antibacterial food packaging effects.
Patent Information
- Application Number
- CN202423263660.7
- 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 lacks antibacterial properties in food packaging, making it difficult to effectively prevent bacterial invasion, and it is easily damaged during use.
It adopts a three-layer composite structure, including PVC cast film, chitin/gelatin composite film and eugenol/modified polyvinyl alcohol composite film, combined with PVDC heat insulation shrink film, and is bonded together with adhesive to form an antibacterial food packaging film, which enhances strength and antibacterial properties.
It improves the strength and antibacterial effect of food packaging film, extends the shelf life of food, ensures safety during the packaging process, and prevents bacterial invasion.
Smart Images
Figure CN223934326U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a cast PVC shrink film, belonging to the field of shrink film technology. Background Technology
[0002] With social development and improved living standards, people have increasingly higher demands for food, and consequently, for the packaging films used. These films need to possess excellent strength and antibacterial properties to prevent bacterial invasion. Antibacterial food packaging can extend the shelf life of food by releasing active substances. Natural antibacterial agents, primarily extracted from plants, are not only widely available and possess excellent antibacterial properties, but are also green, safe, and harmless to living organisms. Therefore, developing a PVC shrink film suitable for food packaging with antibacterial properties has become a key problem to be solved. Utility Model Content
[0003] The purpose of this invention is to provide a cast PVC shrink film with good strength and antibacterial effect.
[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 cast PVC shrink film, comprising a PVC cast film, wherein a chitin / gelatin composite film is laminated on one side surface of the PVC cast film, and a polyvinyl alcohol antibacterial film is laminated on the other side surface, wherein the polyvinyl alcohol antibacterial film 3 is an eugenol / modified polyvinyl alcohol composite film.
[0006] Based on the above scheme and as a preferred embodiment of the above scheme: the PVC cast film includes a first PVC cast layer, a polyethylene fiber mesh layer and a second PVC cast layer.
[0007] Based on the above scheme and as a preferred embodiment of the above scheme: a heat-insulating shrink film 4 is provided between the PVC cast film and the polyvinyl alcohol antibacterial film.
[0008] 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.
[0009] The beneficial effects of this utility model are as follows: The cast PVC shrink film involved in this utility model adopts a three-layer composite structure, which can improve the overall strength of the shrink film and avoid damage to the shrink film during the packaging process. The use of chitosan / gelatin composite film and eugenol / modified polyvinyl alcohol composite film provides good antibacterial and bacteriostatic effects, improving the safety of food packaging. Attached Figure Description
[0010] Figure 1This is a schematic diagram of the structure of the cast PVC shrink film involved in Example 1;
[0011] Figure 2 This is a schematic diagram of the structure of PVC cast film;
[0012] Figure 3 This is a schematic diagram of the structure of the cast PVC shrink film involved in Example 2.
[0013] The markings in the diagram are explained as follows: 1-PVC cast film; 2-Chitin / gelatin composite film; 3-Polyvinyl alcohol antibacterial film; 4-Heat insulation shrink film; 11-First PVC cast layer; 12-Polyvinyl fiber mesh layer; 13-Second PVC cast layer. Detailed Implementation
[0014] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0015] Example 1
[0016] Combination Figure 1 and Figure 2 This embodiment provides a detailed description. The cast PVC shrink film involved in this embodiment includes a PVC cast film 1. One surface of the PVC cast film 1 is laminated with a chitosan / gelatin composite film 2 via an adhesive, and the other surface is laminated with a polyvinyl alcohol antibacterial film 3 via an adhesive. The polyvinyl alcohol antibacterial film 3 is an eugenol / modified polyvinyl alcohol composite film. The adhesive used can be a polyurethane adhesive.
[0017] 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 was prepared by blending gelatin and chitosan using a casting method.
[0018] The water resistance of the composite membrane is improved by adding cellulose nanofibers (CNF) to PVA to form an interwoven polymer network, and then adding citric acid (CA) to chemically crosslink the PVA and CNF. Simultaneously, eugenol (EUG), a natural plant essential oil, is selected as an antibacterial template. The self-emulsifying properties of PVA are used to form an antibacterial composite membrane coated with EUG, exhibiting antibacterial effects.
[0019] Furthermore, the PVC cast film 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.
[0020] Example 2
[0021] Combination Figure 3 This embodiment will be described in detail below. The difference between this embodiment and Embodiment 1 is that a heat-insulating shrink film 4 is provided between the PVC cast film 1 and the polyvinyl alcohol antibacterial film 3. The heat-insulating shrink film 4 is a PVDC heat-insulating shrink film.
[0022] The PVDC heat-insulating shrink film has an outer layer of a first PE layer, which is a mixture of UPE and ethylene-α-olefin copolymer; an outer adhesive layer of EVA resin, used to bond the first PE layer and the intermediate layer; an intermediate layer composed of PVDC resin, epoxidized soybean oil, heat stabilizer and lubricant; an inner adhesive layer of EVA resin, used to bond the second PE layer and the intermediate layer; and an outer layer of a second PE layer, which is a mixture of LLDPE and MLLDPE.
[0023] 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 cast PVC shrink film, characterized in that, The PVC cast film (1) is coated with a chitin / gelatin composite film (2) on one side and a polyvinyl alcohol antibacterial film (3) on the other side. The polyvinyl alcohol antibacterial film (3) is an eugenol / modified polyvinyl alcohol antibacterial composite film.
2. The cast PVC shrink film according to claim 1, characterized in that, The PVC cast film (1) includes a first PVC cast layer (11), a polyethylene fiber mesh layer (12), and a second PVC cast layer (13).
3. The cast PVC shrink film according to claim 1, characterized in that, A heat-insulating shrink film (4) is provided between the PVC cast film (1) and the polyvinyl alcohol antibacterial film (3).
4. The cast PVC shrink film according to claim 3, characterized in that, The heat-insulating shrink film (4) is a PVDC heat-insulating shrink film.