Composite nano-microporous high-preservation breathable membrane

Abstract

The utility model discloses a kind of high-preservation breathable membranes of composite nanometer micropore, including base film layer, nanometer micropore layer, humidity and air conditioning layer, reinforcing layer and composite adhesive layer.Base film layer is located in membrane body middle part, nanometer micropore layer is attached to base film layer one side and has uniform distribution nanometer level micropore, humidity and air conditioning layer is covered in nanometer micropore layer outside, for adjusting air and water vapor passage;Base film layer other side is fixed with reinforcing layer, to promote the tensile and tear resistance of membrane body;Composite adhesive layer is respectively arranged between each layer, so that each layer is firmly combined to form integral structure.The utility model can realize the stable control to gas and humidity, with good breathability, durability and preservation effect, suitable for fruit and vegetable, fresh and food packaging field.

Description

Technical Field

[0001] This utility model relates to the technical field of breathable membranes, and in particular to a composite nanoporous breathable membrane for high preservation. Background Technology

[0002] During the storage and transportation of fresh food, fruits and vegetables, and prepared ingredients, the air permeability and moisture retention properties of packaging materials directly affect their respiration rate, metabolic rate, and spoilage rate. Traditional food preservation films are mostly single-layer polymer films, with simple structures and limited functions, relying primarily on the material's inherently weak air permeability for gas exchange. However, the gas diffusion rate of single-layer films is uncontrollable, and during long-term storage, localized oxygen deficiency and carbon dioxide retention can easily occur, thus accelerating food aging and spoilage.

[0003] Existing technologies also employ microporous breathable membranes, but these typically use mechanical perforation or chemical foaming to create micropores, with pore sizes ranging from tens to hundreds of micrometers. This uneven pore size distribution limits their breathability. If the micropores are too large, water vapor can easily escape rapidly, causing food to lose moisture; if the micropores are too small, insufficient gas exchange can lead to an anaerobic environment. Furthermore, microporous membranes are prone to condensation during use; the adhering moisture can actually block the pores, further reducing the actual breathability.

[0004] Meanwhile, to ensure that breathable membranes meet transportation and stacking requirements, the membrane material typically needs to possess certain tensile strength and puncture resistance. However, traditional breathable membranes, due to their mostly single-layer or simple composite structures, are more prone to stress concentration after micropores form on the film surface, leading to quality problems such as tearing and perforation, making it difficult to maintain packaging integrity. In addition, multilayer composite films are prone to interlayer separation during production and use, affecting their stability and service life.

[0005] In view of this, the inventors have designed a composite nanoporous high-preservation breathable membrane, which leads to this invention. Utility Model Content

[0006] (a) Technical problems to be solved The purpose of this application is to provide a composite nanoporous high-preservation breathable film that at least solves the problems of traditional preservation films, such as low gas exchange efficiency, uneven micropore size leading to unstable respiration regulation, easy condensation and mold growth, insufficient film strength and easy breakage, and easy delamination of multi-layer structure, which affect preservation performance and service life.

[0007] (II) Technical Solution To solve the above-mentioned technical problems, this utility model provides the following technical solution: This application provides a composite nanoporous high-preservation breathable membrane, comprising a base film layer, a nanoporous layer, a humidity-regulating and gas-regulating layer, a reinforcing layer, and a composite adhesive layer: The base film layer serves as a load-bearing structure and is located in the middle of the membrane. The nanoporous layer is attached to one side of the base film layer, and uniformly distributed nanoscale micropores are formed on it. The humidity and gas regulating layer covers the outside of the nanoporous layer and is fixedly connected to the nanoporous layer through the composite adhesive layer, which is used to regulate the gas and water vapor entering the microporous layer. The reinforcing layer is attached to the other side of the base film layer and is fixedly connected to the base film layer through the composite adhesive layer, which is used to improve the overall mechanical strength of the breathable membrane. The composite adhesive layer is used to compositely connect the base film layer, the nanoporous layer, the humidity and gas regulating layer, and the reinforcing layer, so that the membrane forms an integral structure.

[0008] In a further embodiment, the pore size of the nanopores ranges from 50 nm to 200 nm.

[0009] In a further embodiment, the nanopores are uniformly distributed in an array along the membrane surface.

[0010] In a further embodiment, the humidity and air conditioning layer includes microporous regulating channels and moisture-absorbing components for regulating the rate of water vapor diffusion.

[0011] In a further embodiment, the reinforcing layer is an interwoven mesh fiber layer or a tear-resistant membrane.

[0012] In a further embodiment, the base film layer is either a polyethylene film layer or a polypropylene film layer.

[0013] In a further embodiment, the composite adhesive layer is any one of a hot melt adhesive layer, a co-extruded adhesive layer, or an electrostatic composite layer.

[0014] In a further embodiment, the thickness of the reinforcing layer is greater than the thickness of the nanoporous layer.

[0015] In a further embodiment, the base film layer, the nanoporous layer, the humidity and air conditioning layer, and the reinforcing layer are sequentially composited to form a four-layer structure.

[0016] (III) Beneficial Effects Compared with the prior art, the present invention has the following advantages: By setting a nanoscale microporous layer on one side of the base film layer and covering it with a humidity-regulating and gas-regulating layer, the regulation of oxygen, carbon dioxide, and water vapor is achieved, overcoming the problems of uneven gas exchange and unstable preservation caused by excessively large or small pore sizes in traditional microporous membranes. The nanopores are uniformly arrayed, making the breathing channels stable and reliable, and avoiding pore blockage caused by condensation. A reinforcing layer is added on the other side of the base film layer, which enables the film to maintain good air permeability while having higher tensile and puncture resistance, solving the defect of easy tearing of existing breathable membranes. In addition, the multi-layer structure is firmly connected by a composite adhesive layer to form a stable four-layer composite membrane, effectively avoiding the phenomenon of easy delamination of traditional multi-layer membranes, thereby significantly improving the durability and preservation performance of the film during transportation, storage, and long-term use.

[0017] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0018] in: Figure 1 This is a schematic diagram showing the overall structure of each layer of this utility model.

[0019] Label Explanation: 1. Base film layer; 2. Nanoporous layer; 21. Micropores; 3. Humidity and air conditioning layer; 31. Regulation channel; 32. Moisture-absorbing component; 4. Reinforcing layer; 5. Composite adhesive layer. Detailed Implementation

[0020] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0021] like Figure 1 As shown, in this embodiment, the breathable membrane adopts a multi-layer composite structure, including a base membrane layer 1, a nanoporous layer 2, a humidity-regulating and gas-regulating layer 3, a reinforcing layer 4, and a composite adhesive layer 5 located between each layer. The base membrane layer 1 is located in the middle of the membrane body and is preferably made of polyethylene or polypropylene material, which has good flexibility, transparency, and mechanical stability, and is the supporting structure of the entire membrane. To improve the control precision of gas exchange, a nanoporous layer 2 is attached to one side of the base membrane layer 1. The nanoporous layer 21 is firmly connected to the base membrane layer 1 through the composite adhesive layer 5. The nanoporous layer 21 has a large number of nanoscale micropores 21 formed in it, with a pore size ranging from 50nm to 200nm, and is uniformly distributed in an array along the membrane surface, so that the membrane forms a stable breathing channel without significantly affecting the strength.

[0022] A humidity-regulating and gas-regulating layer 3 is disposed on the outside of the nanoporous layer 2. This layer is also fixed by a composite adhesive layer 5. Its interior may include micropores 21, regulating channels 31, and moisture-absorbing components 32 to further regulate the permeation rate of air and water vapor, so that the concentrations of oxygen, carbon dioxide, and water vapor inside the fruit, vegetable, or food packaging are maintained within a reasonable range. When the external humidity is high, the humidity-regulating layer can adsorb or slowly release excess moisture, preventing the gas exchange capacity from decreasing due to condensation clogging the micropores 21. The composite adhesive layer 5 between the humidity-regulating and gas-regulating layer 3 and the nanoporous layer 2 has a continuous and uniform thin-layer structure, ensuring a firm and stable connection between the two without affecting the integrity of the gas channels.

[0023] like Figure 1 As shown, to improve the mechanical properties of the entire film during processing, packaging, and transportation, a reinforcing layer 4 is provided on the other side of the base film layer 1. The reinforcing layer 4 is also firmly bonded to the base film layer 1 through a composite adhesive layer 5. The reinforcing layer 4 can be an interlaced mesh fiber layer or a tear-resistant reinforced film structure, enabling the film to maintain high tensile and puncture resistance even at a relatively thin thickness, making it particularly suitable for fresh food packaging scenarios requiring pressure-resistant stacking or abrasion-resistant transportation. In a preferred embodiment, the thickness of the reinforcing layer 4 is slightly greater than that of the nanoporous layer 2 to further enhance the overall durability and deformation stability.

[0024] like Figure 1 As shown, the composite adhesive layer 5 can be formed using a hot melt adhesive layer, a co-extruded adhesive layer, or an electrostatic lamination method. This adhesive layer not only connects the functional layers but also ensures that the entire film structure is not prone to delamination under thermal changes or mechanical bending conditions, thus improving the long-term reliability of the film. Through the above multi-layer composite structure, the film ultimately forms a four-layer structure system from the outside to the inside: a humidity-regulating layer 3, a nanoporous layer 2, a base film layer 1, and a reinforcing layer 4. Each layer has complementary functions, giving the film good breathability, humidity control capabilities, and high mechanical strength.

[0025] In use, the breathable membrane of this embodiment can be directly applied to the packaging of fresh fruits and vegetables, meat products, and pre-prepared dishes. The nanoporous layer 2 dynamically regulates oxygen and carbon dioxide concentrations, while the humidity-regulating layer 3 maintains a suitable humidity environment, effectively delaying food spoilage and dehydration. Simultaneously, the reinforcing layer 4 improves the overall membrane's resistance to damage, making it more suitable for cold chain transportation and storage. Through the above design, this invention simultaneously solves the problems of unstable gas regulation, easy tearing of the structure, easy blockage of pores due to condensation, and easy delamination of multilayer membranes in traditional microporous membranes, significantly improving the preservation performance and durability of the packaging film.

[0026] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A composite nanoporous high-preservation breathable membrane, comprising a base film layer, a nanoporous layer, a humidity-regulating and gas-regulating layer, a reinforcing layer, and a composite adhesive layer, characterized in that: The base film layer serves as a load-bearing structure and is located in the middle of the membrane. The nanoporous layer is attached to one side of the base film layer, and uniformly distributed nanoscale micropores are formed on it. The humidity and gas regulating layer covers the outside of the nanoporous layer and is fixedly connected to the nanoporous layer through the composite adhesive layer, and is used to regulate the gas and water vapor entering the nanoporous layer. The reinforcing layer is attached to the other side of the base film layer and is fixedly connected to the base film layer through the composite adhesive layer, and is used to improve the overall mechanical strength of the breathable membrane. The composite adhesive layer is used to compositely connect the base film layer, the nanoporous layer, the humidity and gas regulating layer, and the reinforcing layer, so that the membrane forms an integral structure.

2. The composite nanoporous high-preservation breathable membrane according to claim 1, characterized in that, The pore size of the nanopores ranges from 50 nm to 200 nm.

3. A composite nanoporous high-preservation breathable membrane according to claim 1 or 2, characterized in that, The nanopores are uniformly distributed in an array along the membrane surface.

4. The composite nanoporous high-preservation breathable membrane according to claim 1, characterized in that, The humidity and air conditioning layer includes microporous regulating channels and moisture-absorbing components, which are used to regulate the rate of water vapor diffusion.

5. The composite nanoporous high-preservation breathable membrane according to claim 1, characterized in that, The reinforcing layer is an interwoven mesh fiber layer or a tear-resistant membrane material.

6. The composite nanoporous high-preservation breathable membrane according to claim 1, characterized in that, The base film layer is either a polyethylene film layer or a polypropylene film layer.

7. The composite nanoporous high-preservation breathable membrane according to claim 1, characterized in that, The composite adhesive layer is any one of a hot melt adhesive layer, a co-extruded adhesive layer, or an electrostatic composite layer.

8. The composite nanoporous high-preservation breathable membrane according to claim 5, characterized in that, The thickness of the reinforcing layer is greater than the thickness of the nanoporous layer.

9. The composite nanoporous high-preservation breathable membrane according to claim 1, characterized in that, The base film layer, the nanoporous layer, the humidity and air conditioning layer, and the reinforcing layer are sequentially composited to form a four-layer structure.

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