Composite packaging bag

Abstract

The utility model discloses a composite packaging bag which comprises a packaging bag body, and the packaging bag body is sequentially provided with an outer layer, a middle layer, a fragrance keeping layer, a damp-proof layer and an inner layer. The outer layer is a high-strength polyethylene layer with the tensile strength of 20-40 MPa and the tear strength of 10-20 kN / m; the middle layer is an ethylene-vinyl alcohol copolymer layer; the fragrance-keeping layer is a thin film layer made of polyethylene containing a fragrance-keeping agent; the damp-proof layer is a polyvinyl alcohol layer; and the inner layer is a film layer containing nano-silver in polyethylene resin. The packaging bag provided by the utility model has good waterproof performance and air permeability, so that the shelf life of food is prolonged; meanwhile, due to the adoption of the special design of the fragrance-keeping layer, the original flavor of the article is not easy to lose. In addition, the packaging bag further has high corrosion resistance and impact resistance and is suitable for being used in various environments.

Description

Technical Field

[0001] This utility model relates to the field of packaging bag technology, and in particular to a composite packaging bag. Background Technology

[0002] As consumers increasingly demand higher quality products and packaging, the shortcomings of traditional packaging bags in preserving aroma and preventing moisture are becoming more apparent. For products requiring long-term fragrance preservation, such as tea, coffee, and spices, the problem of aroma dissipation from traditional packaging bags severely impacts product quality and user experience. Fragrance molecules easily escape through packaging materials into the external environment, causing the aroma of the product inside to gradually disappear. This not only reduces the product's market competitiveness but also fails to meet consumers' demands for high-quality packaging.

[0003] Furthermore, the penetration of external air and moisture is a major challenge for traditional packaging bags. External moisture entering the packaging bag can cause the product to become damp and spoil, especially for foods and medicines that need to be kept dry. Insufficient moisture-proof performance directly affects the product's shelf life and safety. Traditional packaging materials have limited ability to block air and moisture, making it difficult to provide effective protection.

[0004] In view of this, the inventor has designed a composite packaging bag, which leads to this invention. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] The purpose of this application is to provide a composite packaging bag that at least solves the problems of traditional packaging bags in terms of aroma preservation and moisture protection.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0009] This application provides a composite packaging bag, including a packaging bag body, which comprises, from the outside to the inside: an outer layer, a middle layer, an aroma-preserving layer, a moisture-proof layer, and an inner layer;

[0010] in,

[0011] The outer layer is a high-strength polyethylene film with a tensile strength of 20–40 MPa and a tear strength of 10–20 kN / m, providing resistance to external forces. The middle layer is an ethylene-vinyl alcohol copolymer layer, providing gas barrier properties. The fragrance-retaining layer is a thin film made by adding a fragrance-retaining agent to a polyethylene matrix, located between the middle layer and the moisture-proof layer. The fragrance-retaining agent is an aliphatic ester or aromatic alcohol. The fragrance-retaining layer is bonded to adjacent layers by co-extrusion or coating to inhibit fragrance evaporation. The moisture-proof layer is a polyvinyl alcohol film, used to reduce water vapor permeability. The inner layer is a film made of uniformly dispersed nano-silver in polyethylene resin, used to improve antibacterial properties and enhance the corrosion resistance of the inner surface.

[0012] In a further embodiment, the thickness of the outer layer is 5–8 μm.

[0013] In a further embodiment, the thickness of the intermediate layer is 0.06–0.14 μm.

[0014] In a further embodiment, the thickness of the fragrance-preserving layer is 0.1–0.7 μm.

[0015] In a further embodiment, the thickness of the moisture-proof layer is 0.1–0.9 μm.

[0016] In a further embodiment, the thickness of the inner layer is 0.1–0.5 μm.

[0017] In a further embodiment, the fragrance-preserving layer is bonded to the adjacent intermediate layer and moisture-proof layer through co-extrusion or hot-pressing composite method.

[0018] In a further embodiment, the nano-silver particles have a diameter of 10–50 nm and a dispersion concentration of 0.1–0.5% of the total mass of the inner layer.

[0019] (III) Beneficial Effects

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The packaging bag provided by this utility model has good waterproof performance and breathability, thereby extending the shelf life of food;

[0022] 2. The packaging bag provided by this utility model adopts a special aroma-preserving layer design, which makes the product less likely to lose its original flavor;

[0023] 3. The packaging bag provided by this utility model has strong corrosion resistance and impact resistance, and is suitable for use in various environments.

[0024] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0025] In the attached diagram:

[0026] Figure 1 This is a schematic diagram of the overall structure of the packaging strap body of this utility model;

[0027] Figure 2 This is a schematic diagram of the overall structure of each layer of this utility model;

[0028] Figure 3 This is one embodiment of the present invention that highlights the adhesive layer;

[0029] Figure 4 This is one embodiment of the present invention that highlights the adhesive layer.

[0030] The labels in the diagram are as follows: 10. Packaging tape body; 1. Outer layer; 2. Middle layer; 3. Fragrance preservation layer; 4. Moisture-proof layer; 5. Inner layer; 6. Adhesive layer. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model.

[0032] like Figure 1 and Figure 2 As shown, one embodiment of the present invention provides a composite packaging bag, including a packaging bag body 10, wherein the packaging bag body 10 is sequentially provided with an outer layer 1, a middle layer 2, an aroma-preserving layer 3, a moisture-proof layer 4, and an inner layer 5.

[0033] like Figure 2 As shown, the outer layer 1 is a high-strength polyethylene layer with a tensile strength between 20-40 MPa and a tear strength between 10-20 kN / m. This film layer has excellent physical and mechanical properties and is located at the outermost layer 1 of the packaging bag. It is formed by high-frequency heat sealing technology, providing the packaging bag with mechanical strength and durability. By setting this high-strength polyethylene film layer, the mechanical strength of the packaging bag body can be improved during transportation and use, thereby enhancing the packaging bag's resistance to external forces (such as compression, impact, etc.), effectively preventing damage, and extending the service life of the packaging bag. The outer layer 1 wraps around the entire exterior of the packaging bag and is tightly bonded to the middle layer 2.

[0034] The intermediate layer 22 is an ethylene-vinyl alcohol copolymer layer, which is closely attached to the inside of the outer layer 1 material and is sealed to the outer layer 1 material through co-extrusion technology, providing excellent barrier properties. The intermediate layer 2 is located between the outer layer 1 and the fragrance preservation layer 3, ensuring that external air and moisture cannot penetrate.

[0035] The fragrance-retaining layer 3 is a thin film layer made of polyethylene with added fragrance-retaining agents. These agents can be aliphatic esters or aromatic alcohols, used to adsorb and lock in the product's fragrance molecules, reducing fragrance evaporation. The fragrance-retaining layer is bonded to the intermediate layer 2 and the moisture-proof layer 4 through co-extrusion or coating processes to form a stable composite structure. The fragrance-retaining layer 3 is positioned between the intermediate layer 2 and the moisture-proof layer 4, synergistically achieving both gas barrier and fragrance retention functions.

[0036] The moisture-proof layer 4 is a polyvinyl alcohol layer, tightly attached to the inner side of the fragrance-preserving layer 3. It is bonded to the fragrance-preserving layer 3 through co-extrusion or coating technology. This layer has excellent water-blocking properties, effectively reducing the overall moisture permeability of the packaging bag. By placing it between the fragrance-preserving layer and the inner layer, it effectively prevents moisture from entering the packaging bag in humid environments, ensuring the dryness and stability of the packaged goods. Tests have shown that the moisture-proof layer 4 using a polyvinyl alcohol film can reduce the overall moisture permeability of the packaging bag by more than 30%, helping to improve the moisture-proof effect of the packaging bag. The moisture-proof layer 4 is located between the fragrance-preserving layer 3 and the inner layer 5, ensuring the dryness and freshness of the product inside the packaging bag. Preparation method: Polyvinyl alcohol resin is dissolved in water to prepare a solution, which is then sprayed into a film through a spinneret. After drying and curing, the film is stretched to obtain the moisture-proof layer 4.

[0037] In a preferred embodiment, the inner layer 5 is a thin film layer made of uniformly dispersed silver nanoparticles in polyethylene resin. The silver nanoparticles have a particle size of 10-50 nm and a dispersion mass concentration of 0.1-0.5% of the total mass of the inner layer. The film layer is formed by melt blending and extrusion. This structure can release silver ions, which disrupt bacterial cell membranes, thereby achieving antibacterial and anti-corrosion functions. The dispersion of silver nanoparticles enhances the antibacterial and anti-corrosion properties of the inner layer 5 while maintaining the excellent physical properties of the polyethylene resin. Specifically, the uniform distribution of silver nanoparticles not only improves the antibacterial properties of the packaging bag but also enhances the corrosion resistance of the inner layer 5, protecting the contents of the packaging from external contamination or chemical corrosion. Experimental data show that packaging bags using a silver nanoparticle inner layer have significantly improved antibacterial and moisture-proof effects during long-term storage. Adhering closely to the inside of the moisture-proof layer 4, it is combined with the moisture-proof layer 4 through co-extrusion or coating technology, directly contacting the product inside the packaging bag, inhibiting bacterial growth, and ensuring food safety. The inner layer 5 material is located in the innermost layer 5 of the packaging bag, directly contacting the product inside, providing final protection.

[0038] The packaging bag body 10 has excellent waterproof and breathable properties, thus extending the shelf life of food. Simultaneously, thanks to the special aroma-preserving layer 3 design, the product retains its original flavor. Furthermore, the packaging bag body 10 possesses strong corrosion resistance and impact resistance, making it suitable for use in various environments.

[0039] Furthermore, the thickness of the outer layer 1 ranges from 5 μm to 8 μm.

[0040] Furthermore, the thickness of the intermediate layer 2 ranges from 0.06 μm to 0.14 μm.

[0041] Furthermore, the thickness of the fragrance-preserving layer 3 ranges from 0.1 μm to 0.7 μm.

[0042] Furthermore, the thickness of the moisture barrier 4 ranges from 0.1 μm to 0.9 μm.

[0043] Furthermore, the thickness of the inner layer 5 material ranges from 5μm to 8μm.

[0044] like Figure 3 and Figure 4 As shown, it also includes an adhesive layer 6, which is located between the outer layer 11 and the intermediate layer 22, or between the fragrance layer 3 and the moisture-proof layer 4. The adhesive layer 6 is a polypropylene layer. The adhesive layer 6 enhances the adhesion between the layers, ensuring the stability and integrity of the multilayer structure.

[0045] The composite packaging bag of this invention utilizes existing mature film processing technologies such as co-extrusion and hot-pressing to achieve a stable composite structure of multi-layer materials, resulting in good adhesion between functional layers and high film uniformity. According to the ASTM E96 water vapor transmission rate test method, the moisture-proof layer can control the water vapor transmission rate to below 0.5 g / m² / day; the aroma-preserving layer has a significantly lower permeability coefficient for alcohol gases than traditional single-layer polyethylene films at 25℃, effectively extending the preservation time of food aroma.

[0046] This utility model provides a method for manufacturing a composite packaging bag, the specific steps of which are as follows:

[0047] S1: Prepare outer layer 1 by selecting high-strength polyethylene (HDPE or UHMWPE) resin. Melt and extrude the polyethylene resin using an extruder to form a film of outer layer 1. Cool the film and wind it into a roll with a thickness ranging from 5μm to 8μm.

[0048] S2: Prepare intermediate layer 2 using ethylene and vinyl alcohol monomers as raw materials. Prepare ethylene-vinyl alcohol copolymer (EVOH) resin through copolymerization. Fabricate EVOH resin into films with a thickness ranging from 0.06 μm to 0.14 μm using blow molding or casting techniques.

[0049] S3: Preparation of the Fragrance Retention Layer 3: Polyethylene resin, aliphatic dicarboxylic acid ester compounds (fragrance retainer), organotin catalyst, and antioxidant are mixed. The mixture is melt-blended uniformly in a mixer. The melt-blended material is then blow-molded into a film with a thickness ranging from 0.1 μm to 0.7 μm. The film is then subjected to corona treatment to improve its fragrance retention performance.

[0050] S4: Preparation of the moisture-proof layer 4. Polyvinyl alcohol (PVA) resin is dissolved in water to prepare a PVA solution of a certain concentration. The PVA solution is sprayed into a film through a spinneret. The PVA film is then dried and cured. The dried and cured PVA film is then stretched to a thickness ranging from 0.1 μm to 0.9 μm.

[0051] S5: To prepare the inner layer 5, polyethylene resin is mixed with an antibacterial agent (such as nano-silver or quaternary ammonium salt). The mixture is melt-blended uniformly in a mixer. The melt-blended material is then blow-molded into a film with a thickness ranging from 5μm to 8μm.

[0052] S6: Interlayer bonding treatment, which requires enhancing the adhesion between layers, selects to add a polypropylene layer as the bonding layer 6. The polypropylene layer is placed between the outer layer 1 material and the middle layer 2 material, or between the fragrance layer 3 and the moisture-proof layer 4.

[0053] S7: Multi-layer composite, where outer layer 1, middle layer 2, aroma-preserving layer 3, moisture-proof layer 4, and inner layer 5 are sequentially laminated together using co-extrusion or lamination techniques. High-frequency heat sealing technology is then used to tightly bond each layer, forming a multi-layer composite packaging bag.

[0054] S8: Finished product processing. The laminated multilayer film is cut and heat-sealed to form packaging bags of the required specifications. The packaging bags are then inspected to ensure that all performance indicators meet the requirements.

[0055] In summary, the multi-layer composite packaging bag body 10 of this utility model can be widely used in food packaging that requires long-term preservation of aroma, such as tea, coffee, and spices, as well as in pharmaceutical and cosmetic packaging that has high requirements for moisture-proof and antibacterial properties.

[0056] 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 packaging bag, characterized in that, The packaging bag body (10) includes, from the outside to the inside, the following components: Outer layer (1), middle layer (2), fragrance layer (3), moisture-proof layer (4) and inner layer (5); in, The outer layer (1) is a high-strength polyethylene film layer with a tensile strength of 20-40 MPa and a tear resistance of 10-20 kN / m, which is used to provide resistance to external forces; The intermediate layer (2) is an ethylene-vinyl alcohol copolymer layer, used to provide gas barrier properties; The fragrance-preserving layer (3) is a thin film layer made by adding fragrance-preserving agent to polyethylene matrix, located between the intermediate layer (2) and the moisture-proof layer (4). The fragrance-preserving agent is an aliphatic ester or aromatic alcohol. The fragrance-preserving layer is combined with the adjacent layer by co-extrusion or coating to inhibit fragrance volatilization. The moisture-proof layer (4) is a polyvinyl alcohol film layer, used to reduce water vapor permeability; The inner layer (5) is a film layer made of uniformly dispersed nano-silver in polyethylene resin, which is used to improve antibacterial properties and enhance the corrosion resistance of the inner surface.

2. The composite packaging bag according to claim 1, characterized in that, The outer layer (1) has a thickness of 5 to 8 μm.

3. The composite packaging bag according to claim 1, characterized in that, The thickness of the intermediate layer (2) is 0.06 to 0.14 μm.

4. A composite packaging bag according to claim 1, characterized in that, The thickness of the fragrance-preserving layer (3) is 0.1 to 0.7 μm.

5. A composite packaging bag according to claim 1, characterized in that, The thickness of the moisture-proof layer (4) is 0.1 to 0.9 μm.

6. A composite packaging bag according to claim 1, characterized in that, The thickness of the inner layer (5) is 0.1 to 0.5 μm.

7. A composite packaging bag according to claim 1, characterized in that, The fragrance-preserving layer (3) is bonded to the adjacent intermediate layer (2) and moisture-proof layer (4) through co-extrusion or hot-pressing composite method.

8. A composite packaging bag according to claim 1, characterized in that, The nano-silver particles have a diameter of 10–50 nm and a dispersion concentration of 0.1–0.5% of the total mass of the inner layer.

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