Paper-plastic packaging film

Abstract

The utility model provides a paper-plastic packaging film which comprises a paper layer and a plastic layer, and the paper layer at least covers part of the plastic layer. The plastic layer comprises a polypropylene plastic layer and an aluminum-plated layer, and the aluminum-plated layer at least partially covers the polypropylene plastic layer; wherein the paper layer and the plastic layer are compounded through an adhesive. According to the paper-plastic packaging film, the recyclable paper layer is introduced on the plastic layer, the recovery rate of the paper-plastic packaging film is improved while the barrier rate is guaranteed, the paper layer and the plastic layer are compounded through an adhesive, a good compounding effect can be obtained, and the paper layer is prevented from being separated in the normal use process.

Description

Technical Field

[0001] The utility model relates to the technical field of packaging materials, and in particular to a paper-plastic packaging film. Background Art

[0002] Flexible packaging films are widely used because of their good barrier properties, mechanical properties, heat-sealing properties, etc. In related technologies, flexible packaging films are usually plastic composite films, which are difficult to simultaneously achieve environmentally friendly recyclability, stable size and friction coefficient, exquisite appearance after packaging, high barrier, etc., while more environmentally friendly paper packaging cannot provide good barrier properties, and the shelf life cannot be guaranteed. Many fast-moving consumer goods customers cannot accept it, or can only use it as secondary packaging. Therefore, how to make flexible packaging films have both barrier properties and recyclability has always been the research goal of experts in this field. Utility Model Content

[0003] The utility model aims to solve at least one of the above technical problems.

[0004] To this end, the first purpose of the utility model is to provide a paper-plastic packaging film.

[0005] The second purpose of the utility model is to provide a method for preparing a paper-plastic packaging film.

[0006] To achieve the first purpose of the utility model, the utility model provides a paper-plastic packaging film, comprising a paper layer and a plastic layer, wherein the paper layer at least covers a portion of the plastic layer; the plastic layer comprises a polypropylene plastic layer and an aluminum-plated layer, wherein the aluminum-plated layer at least partially covers the polypropylene plastic layer; wherein the paper layer and the plastic layer are compounded by an adhesive.

[0007] Compared with the prior art, the technical effects achieved by adopting the technical scheme are as follows: the utility model improves the recycling rate of the paper-plastic packaging film by introducing a recyclable paper layer on the plastic layer; the paper layer is laminated on the plastic layer by an adhesive, so as to obtain a better lamination effect and prevent the paper layer from falling out during normal use; the polypropylene plastic layer further has an aluminum-plated layer, and the presence of the aluminum-plated layer can further improve the barrier properties of the polypropylene plastic layer, making the paper-plastic packaging film of the utility model an ideal choice for packaging sensitive products such as food and medicine, and effectively extending the shelf life of the products.

[0008] In addition, the technical solution provided by the utility model may also have the following technical features:

[0009] In the above technical features, the thickness of the polypropylene plastic layer is 6μm-10μm; and / or the thickness of the aluminum-plated layer is 0.03μm-0.05μm.

[0010] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the use of the polypropylene plastic layer and the aluminum-plated layer of the above-mentioned thickness can ensure the barrier performance of the paper-plastic packaging film as much as possible while using a thinner plastic layer, which can reduce the content of polypropylene and aluminum in the paper-plastic packaging film and further improve the recyclability of the paper-plastic packaging film.

[0011] In any of the above technical features, the polypropylene plastic layer includes an outer heat-sealing layer, a core layer and an inner heat-sealing layer; the aluminum-plated layer at least partially covers the outer heat-sealing layer; the core layer is arranged between the outer heat-sealing layer and the inner heat-sealing layer; wherein the outer heat-sealing layer and the inner heat-sealing layer include copolymer polypropylene, and the core layer includes homopolymer polypropylene.

[0012] Compared with the existing technology, the technical effects achieved by adopting this technical solution are as follows: the outer heat sealing layer adopts copolymer polypropylene, which can improve the adhesion of the aluminum-plated layer and enable the aluminum to be better deposited on the outer heat sealing layer; the core layer adopts homopolymer polypropylene, which can reduce costs while ensuring performance; the inner heat sealing layer adopts homopolymer polypropylene, which can make the prepared paper-plastic packaging film have better heat sealing performance.

[0013] In any of the above technical features, the thickness ratio of the outer heat sealing layer, the core layer and the inner heat sealing layer is 1:8-10:1.

[0014] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the outer heat-sealing layer, the core layer and the inner heat-sealing layer are adopted with the above-mentioned thickness ratio, and the thickness of each layer is appropriate, so that the prepared paper-plastic packaging film has good barrier properties and heat-sealing properties, and the aluminum plating effect is better.

[0015] In any of the above technical features, the paper-plastic packaging film also includes a glue coating layer; the glue coating layer is coated under the inner heat sealing layer; the glue coating layer includes heat sealing glue or cold sealing glue.

[0016] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: a glue coating layer is provided under the inner heat sealing layer, and the glue coating layer can select hot sealing glue or cold sealing glue as needed, thereby further improving the application scenarios and sealing performance of the paper-plastic packaging film.

[0017] In any of the above technical features, the weight of the paper layer is 60g / m 2 -100g / m 2 .

[0018] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: by adopting the above-mentioned paper weight, the recycling rate of the paper-plastic packaging film can be further improved, so that the paper-plastic packaging film reaches a high recycling standard and makes the paper-plastic packaging film more green and environmentally friendly.

[0019] In any of the above technical features, the paper layer is also coated with varnish.

[0020] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: coating varnish on the paper layer can provide the paper layer with a certain waterproof performance, avoiding delamination between the paper layer and the plastic layer due to moisture; at the same time, the varnish can also protect the ink on the paper layer after printing, making the appearance of the paper-plastic packaging film more beautiful.

[0021] After adopting the technical solution of the utility model, the technical effects that can be achieved are as follows:

[0022] 1. The utility model improves the recycling rate of the paper-plastic packaging film by introducing a recyclable paper layer on the plastic layer. By using an adhesive to laminate the paper layer and the plastic layer, a better lamination effect can be obtained to prevent the paper layer from falling out during normal use;

[0023] 2. The polypropylene plastic layer further has an aluminum-plated layer. The presence of the aluminum-plated layer can further improve the barrier properties of the polypropylene plastic layer;

[0024] 3. The outer heat-sealing layer is made of copolymer polypropylene, which can improve the adhesion of the aluminum-plated layer and enable aluminum to be better deposited on the outer heat-sealing layer; the core layer is made of homopolymer polypropylene, which can reduce costs while ensuring performance; the inner heat-sealing layer is made of copolymer polypropylene, which can make the prepared paper-plastic packaging film have better heat-sealing properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A schematic diagram of a paper-plastic packaging film according to an embodiment of the utility model;

[0027] Figure 2 for Figure 1 A partial enlarged view of the middle part;

[0028] Description of reference numerals: 100 - paper layer, 200 - plastic layer, 210 - aluminum-plated layer, 220 - polypropylene plastic layer, 221 - outer heat-sealing layer, 222 - core layer, 223 - inner heat-sealing layer. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0031] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the following is a brief description of the present invention. Figure 1 The specific embodiments of the present utility model are described in detail.

[0032] In the related technology, the existing soft package packaging film structure is usually a plastic composite film structure. The non-recyclable structures include PET / PE, PET / (VM)CPP, PET / MPET / PE, BOPP / MPET / PE, etc., and the recyclable structures include BOPP / PE, BOPP / (VM)CPP, BOPP / MOPP / PE, etc. The non-recyclable packaging film does not meet the increasingly severe environmental protection trend. The recyclable packaging film usually has poor dimensional stability, friction coefficient, and appearance after packaging, which makes it difficult to fully meet customer expectations. Moreover, although plastic composite films can be recycled at this stage, there are actually few recycling companies. In addition, the recycling technology is not yet mature, and the recycling of packaging is still relatively difficult.

[0033] In view of this, an embodiment of the utility model provides a paper-plastic packaging film, which improves the recycling rate of the paper-plastic packaging film by compounding a paper layer on a plastic layer.

[0034] Specifically, an embodiment of the utility model provides a paper-plastic packaging film, comprising a paper layer 100 and a plastic layer 200, wherein the paper layer 100 at least covers a portion of the plastic layer 200; the plastic layer 200 comprises a polypropylene plastic layer 220 and an aluminum-plated layer 210, wherein the aluminum-plated layer 210 at least partially covers the polypropylene plastic layer 220; wherein the paper layer 100 and the plastic layer 200 are compounded by an adhesive.

[0035] Preferably, the utility model improves the recycling rate of the paper-plastic packaging film by introducing a recyclable paper layer 100 on the plastic layer 200; the paper layer 100 is compounded on the plastic layer 200 by an adhesive, and the adhesive is preferably a water-based protein adhesive, which can obtain a better compounding effect and prevent the paper layer 100 from falling out during normal use; the polypropylene plastic layer 220 further has an aluminum-plated layer 210, and the presence of the aluminum-plated layer 210 can further improve the barrier performance of the polypropylene plastic layer 220, making the paper-plastic packaging film of the utility model an ideal choice for packaging sensitive products such as food and medicine, and effectively extending the shelf life of the products.

[0036] Preferably, the thickness of the polypropylene plastic layer 220 is 6 μm-10 μm; and / or the thickness of the aluminum-plated layer 210 is 0.03 μm-0.05 μm, which can reduce the content of polypropylene and aluminum in the paper-plastic packaging film while ensuring the barrier properties of the paper-plastic packaging film as much as possible, thereby further improving the recyclability of the paper-plastic packaging film.

[0037] Preferably, the polypropylene plastic layer 220 includes an outer heat-sealing layer 221, a core layer 222 and an inner heat-sealing layer 223; the aluminum-plated layer 210 at least partially covers the outer heat-sealing layer 221; the core layer 222 is arranged between the outer heat-sealing layer 221 and the inner heat-sealing layer 223; wherein the outer heat-sealing layer 221 and the inner heat-sealing layer 223 include copolymerized polypropylene, and the core layer 222 includes homopolymerized polypropylene.

[0038] Preferably, the outer heat sealing layer 221 is made of copolymer polypropylene, which can improve the adhesion of the aluminum-plated layer 210 and enable aluminum to be better deposited on the outer heat sealing layer 221; the inner heat sealing layer 223 is made of homopolymer polypropylene, which can make the prepared paper-plastic packaging film have better heat sealing performance; the core layer 222 is made of homopolymer polypropylene, which can reduce costs while ensuring barrier properties.

[0039] Furthermore, the thickness ratio of the outer heat-sealing layer 221, the core layer 222 and the inner heat-sealing layer 223 is 1:8-10:1. The thickness of each layer is appropriate, so that the prepared paper-plastic packaging film has good barrier properties and heat-sealing properties, and makes the aluminum plating effect better.

[0040] Preferably, the paper-plastic packaging film further comprises a glue coating layer; the glue coating layer is coated under the inner heat-sealing layer 223; the glue coating layer comprises heat-sealing glue or cold-sealing glue.

[0041] Preferably, a coating layer is provided under the inner heat-sealing layer 223. The coating layer can be made of heat-sealing glue or cold-sealing glue as needed. The heat-sealing glue is preferably water-based acrylic, and the cold-sealing glue is preferably natural latex, which can further improve the application scenarios and sealing performance of the plastic packaging film.

[0042] Preferably, the weight of the paper layer 100 is 60 g / m 2 -100g / m 2 , the recycling rate of paper-plastic packaging film can be further improved, so that the paper-plastic packaging film can reach high recycling standards and make the paper-plastic packaging film more green and environmentally friendly.

[0043] Preferably, the paper layer 100 is also coated with varnish. Coating the varnish on the paper layer 100 can provide the paper layer 100 with a certain waterproof performance, thereby preventing delamination between the paper layer 100 and the plastic layer 200 due to moisture. At the same time, the varnish can also protect the ink on the paper layer 100 after printing, thereby making the appearance of the paper-plastic packaging film more beautiful.

[0044] Furthermore, the varnish includes: 35wt.%-43wt.% waterproof modified polyurethane, 17wt.%-25wt.% polyacrylic acid, 12wt.%-20wt.% waterproof filler, 9wt.%-11wt.% waterproof wax, 5wt.%-9wt.% leveling agent, 2wt.%-5wt.% dispersant, and 2wt.%-5wt.% defoaming agent; wherein the waterproof filler is preferably waterproof modified mica powder.

[0045] Preferably, the method for preparing the paper-plastic packaging film comprises:

[0046] S100, after melt casting and extruding polypropylene, biaxially stretching it into a film, and sequentially subjecting it to corona treatment and aluminum plating treatment to obtain a plastic layer;

[0047] S200, coating adhesive on the aluminum-plated surface of the plastic layer, and laminating the paper layer on the plastic layer to obtain a paper-plastic packaging film.

[0048] Preferably, the molten copolymer polypropylene and homopolypropylene are respectively cast and extruded from three guide rollers and biaxially stretched into a polypropylene plastic layer, so that the polypropylene plastic layer has an outer heat-sealing layer, a core layer and an inner heat-sealing layer from top to bottom, and then corona treatment and aluminum plating treatment are performed in sequence. The corona treatment can increase the surface energy of the outer heat-sealing layer of the polypropylene plastic layer, and the dyne value of the surface of the polypropylene plastic layer after corona treatment is above 38 dyne, further improving the adhesion of the polypropylene plastic layer to the aluminum-plated layer; then, an adhesive is applied to the aluminum-plated surface of the plastic layer and a paper layer is compounded thereon. Preferably, the paper layer is compounded on the plastic layer by a solvent-free compounding method to avoid the paper layer absorbing solvent or using a dry compounding process to cause excessive residual solvent. The use of a solvent-free compounding process can avoid the risk of excessive residual solvent and effectively control the residual solvent to ≤5 mg / m 2 within the national standard range.

[0049] Preferably, the paper layer needs to be printed before solvent-free lamination, and varnish is coated on the paper layer after printing, which can protect the ink and make the paper layer have a certain waterproof performance. The paper layer is preferably made of one of bleached kraft paper, original kraft paper or glassine paper with high strength, tear resistance and high breakage resistance.

[0050] Preferably, the paper-plastic packaging film obtained by the preparation method of the utility model can be recycled into paper through a mature paper fiber recycling method in the market after use, and a fiber recovery rate of more than 80% can be achieved, which greatly reduces the use of petroleum-based plastic materials and improves the problem of white pollution to the greatest extent. It also has good printing effect, high flatness, stable cursor spacing, and a more high-end material, and is suitable for rapid packaging on vertical form fill seal packaging machines (VFFS) and thermoform fill seal packaging machines (HFFS) packaging lines.

[0051] Preferably, the aluminum plating treatment is a vacuum aluminum plating treatment. The vacuum aluminum plating treatment can ensure that aluminum atoms can be evenly deposited on the surface of the polypropylene film in a pure environment, and can effectively prevent aluminum atoms from contacting with oxygen in the air, thereby avoiding oxidation of aluminum atoms. It can not only make the film layer uniform on a macroscopic level, but also obtain higher density and fewer defects on a microscopic level, thereby improving the quality and performance of the coating.

[0052] Preferably, after the paper layer is laminated on the plastic layer, an aging treatment is also included; the aging treatment time is 36h-50h, and the aging treatment is mainly to ensure that the adhesive is completely cured and enhance the composite strength and stability of the paper-plastic packaging film; the above-mentioned aging treatment time can make the aging treatment effect better.

[0053] Preferably, after the aging treatment, the inner heat-sealing layer may be coated with glue as needed, and the coating may be performed using hot-sealing glue or cold-sealing glue according to actual needs or customer requirements to achieve the sealing function of the finished film.

[0054] [Example 1]

[0055] The present embodiment provides a paper-plastic packaging film, including a paper layer and a plastic layer, the paper layer and the plastic layer are compounded together by a water-based protein adhesive, the plastic layer includes an aluminum-plated layer and a polypropylene plastic layer, the polypropylene plastic layer includes an outer heat-sealing layer, a core layer and an inner heat-sealing layer from top to bottom, the aluminum-plated layer covers the outer heat-sealing layer, the paper layer is compounded on the aluminum-plated layer, and the dry weight of the paper layer is 60g / m 2 The thickness of the aluminum plating layer is 0.03 μm, the thickness of the polypropylene plastic layer is 6 μm, wherein the thickness ratio of the outer heat sealing layer, the core layer and the inner heat sealing layer is 1:8:1; the preparation method of the paper-plastic packaging film comprises:

[0056] S100, casting and extruding the molten copolymer polypropylene, homopolymer polypropylene and copolymer polypropylene from three guide rollers respectively and biaxially stretching them into polypropylene plastic layers, and sequentially subjecting them to corona treatment and aluminum plating treatment to obtain plastic layers;

[0057] S200, printing on primary color kraft paper, coating varnish on the primary color kraft paper after drying the ink, coating a water-based protein adhesive on the aluminum-plated surface of the plastic layer, laminating the primary color kraft paper on the plastic layer in a solvent-free laminating manner, and aging for 36 hours to obtain a paper-plastic packaging film;

[0058] The varnish includes: 43wt.% waterproof modified polyurethane, 17wt.% polyacrylic acid, 20wt.% waterproof modified mica, 11wt.% waterproof wax, 5wt.% leveling agent, 2wt.% dispersant, and 2wt.% defoaming agent.

[0059] [Example 2]

[0060] The present embodiment provides a paper-plastic packaging film, comprising a paper layer and a plastic layer, wherein the paper layer and the plastic layer are compounded together by a water-based protein adhesive, wherein the plastic layer comprises an aluminum-plated layer and a polypropylene plastic layer, wherein the polypropylene plastic layer comprises an outer heat-sealing layer, a core layer and an inner heat-sealing layer from top to bottom, wherein the aluminum-plated layer covers the outer heat-sealing layer, and the paper layer is compounded on the aluminum-plated layer, wherein the dry weight of the paper layer is 100 g / m 2 The thickness of the aluminum plating layer is 0.05 μm, the thickness of the polypropylene plastic layer is 10 μm, wherein the thickness ratio of the outer heat sealing layer, the core layer and the inner heat sealing layer is 1:10:1; the preparation method of the paper-plastic packaging film comprises:

[0061] S100, casting and extruding the molten copolymer polypropylene, homopolymer polypropylene and copolymer polypropylene from three guide rollers respectively and biaxially stretching them into polypropylene plastic layers, and sequentially subjecting them to corona treatment and vacuum aluminum plating treatment to obtain plastic layers;

[0062] S200, printing on bleached kraft paper, coating varnish on the bleached kraft paper after drying the ink, coating a water-based protein adhesive on the aluminum-plated surface of the plastic layer, laminating the bleached kraft paper on the plastic layer by a solvent-free lamination method, aging for 50 hours, coating water-based acrylic acid on the inner heat seal layer, and obtaining a paper-plastic packaging film;

[0063] The varnish includes: 35wt.% waterproof modified polyurethane, 25wt.% polyacrylic acid, 12wt.% waterproof modified mica, 9wt.% waterproof wax, 9wt.% leveling agent, 5wt.% dispersant, and 5wt.% defoaming agent.

[0064] [Example 3]

[0065] The present embodiment provides a paper-plastic packaging film, including a paper layer and a plastic layer, the paper layer and the plastic layer are compounded together by a water-based protein adhesive, the plastic layer includes an aluminum-plated layer and a polypropylene plastic layer, the polypropylene plastic layer includes an outer heat-sealing layer, a core layer and an inner heat-sealing layer from top to bottom, the aluminum-plated layer covers the outer heat-sealing layer, the paper layer is compounded on the aluminum-plated layer, and the dry weight of the paper layer is 80g / m 2 The thickness of the aluminum plating layer is 0.04 μm, the thickness of the polypropylene plastic layer is 8 μm, wherein the thickness ratio of the outer heat sealing layer, the core layer and the inner heat sealing layer is 1:8:1; the preparation method of the paper-plastic packaging film comprises:

[0066] S100, casting and extruding the molten copolymer polypropylene, homopolymer polypropylene and copolymer polypropylene from three guide rollers respectively and biaxially stretching them into polypropylene plastic layers, and sequentially subjecting them to corona treatment and vacuum aluminum plating treatment to obtain plastic layers;

[0067] S200, printing glassine paper, coating varnish on the glassine paper after drying the ink, coating a water-based protein adhesive on the aluminum-plated surface of the plastic layer, laminating the glassine paper on the plastic layer by a solvent-free lamination method, aging for 48 hours, coating natural latex on the inner heat seal layer, and obtaining a paper-plastic packaging film;

[0068] The varnish includes: 40wt.% waterproof modified polyurethane, 20wt.% polyacrylic acid, 15wt.% waterproof modified mica, 10wt.% waterproof wax, 7wt.% leveling agent, 4wt.% dispersant, and 4wt.% defoaming agent.

[0069] [Comparative Example 1]

[0070] This embodiment provides a paper-plastic packaging film, including a paper layer and a plastic layer, wherein the paper layer and the plastic layer are laminated together by a polyurethane adhesive, and the dry weight of the paper layer is 40 g / m 2 , the thickness of the plastic layer is 20 μm, and the preparation method of the paper-plastic packaging film comprises:

[0071] S100, casting and extruding the molten polypropylene and biaxially stretching it into a plastic layer;

[0072] S200, printing the original color kraft paper, drying the ink, coating the plastic layer with a polyurethane adhesive, and laminating the original color kraft paper on the plastic layer by a solvent-free lamination method to obtain a paper-plastic packaging film.

[0073] [Comparative Example 2]

[0074] This embodiment provides a paper-plastic packaging film, including a paper layer and a plastic layer, wherein the paper layer and the plastic layer are laminated together by a polyurethane adhesive, and the dry weight of the paper layer is 40 g / m 2 , the thickness of the plastic layer is 15 μm, and the preparation method of the paper-plastic packaging film comprises:

[0075] S100, casting and extruding the molten polypropylene and biaxially stretching it into a plastic layer;

[0076] S200, printing the original color kraft paper, drying the ink and applying varnish, applying polyurethane adhesive on the plastic layer, and laminating the original color kraft paper on the plastic layer by a solvent-free lamination method to obtain a paper-plastic packaging film;

[0077] Among them, varnish is varnish for paper purchased on the market.

[0078]

Performance test

[0079] 1. The recovery rates of the paper-plastic packaging films of Examples 1-3 and Comparative Examples 1-2 were determined by component analysis;

[0080] 2. The paper-plastic packaging films of Examples 1-3 and Comparative Examples 1-2 were tested for oxygen transmission rate at 23°C and 0% RH, and tested for water vapor transmission rate at 38°C and 90% RH;

[0081] The test results are shown in Table 1:

[0082] Table 1

[0083] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Recovery rate / % 82 84 87 42 50 <![CDATA[Water vapor transmission rate / g / (m 2 × 24 h)]]> 0.9 0.7 0.6 3.6 6.9 <![CDATA[Oxygen Transmission Rate / cc / (m 2 × 24 h)]]> 4.5 4.0 3.9 47.6 76.9

[0084] As can be seen from Table 1, the recovery rate, water vapor permeability and oxygen permeability of the paper-plastic packaging films of Examples 1-3 of the present invention are better than those of the paper-plastic packaging films of Comparative Examples 1-2, especially the paper-plastic packaging film in Comparative Example 3, which may be due to the use of more suitable thicknesses of each layer and gram weight of the paper layer; the recovery rates of the paper-plastic packaging films of Comparative Examples 1-2 are relatively poor, and the water vapor permeability and oxygen permeability of the paper-plastic packaging film in Comparative Example 1 are slightly better, which may be due to the fact that its plastic layer is thicker and has better barrier properties, but its paper layer has a smaller gram weight, so its recovery rate is not high; the plastic layer of the paper-plastic packaging film in Comparative Example 2 is thinner than that of Comparative Example 1, so its water vapor permeability and oxygen permeability are worse than those of Comparative Example 1.

[0085] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A paper-plastic packaging film, characterized in that: It comprises a paper layer (100) and a plastic layer (200), The paper layer (100) at least covers a portion of the plastic layer (200); The plastic layer (200) comprises a polypropylene plastic layer (220) and an aluminum-plated layer (210), wherein the aluminum-plated layer (210) at least partially covers the polypropylene plastic layer (220); Wherein, the paper layer (100) and the plastic layer (200) are compounded by an adhesive.

2. The paper-plastic packaging film according to claim 1, characterized in that: The thickness of the polypropylene plastic layer (220) is 6 μm-10 μm; and / or The thickness of the aluminum plating layer (210) is 0.03 μm-0.05 μm.

3. The paper-plastic packaging film according to any one of claims 1 and 2, characterized in that: The polypropylene plastic layer (220) comprises an outer heat-sealing layer (221), a core layer (222) and an inner heat-sealing layer (223); The aluminum-plated layer (210) at least partially covers the outer heat-sealing layer (221); The core layer (222) is arranged between the outer heat-sealing layer (221) and the inner heat-sealing layer (223); Wherein, the outer heat-sealing layer (221) and the inner heat-sealing layer (223) include copolymerized polypropylene, and the core layer (222) includes homopolymerized polypropylene.

4. The paper-plastic packaging film according to claim 3, characterized in that: The thickness ratio of the outer heat-sealing layer (221), the core layer (222) and the inner heat-sealing layer (223) is 1:8-10:

1.

5. The paper-plastic packaging film according to claim 3, characterized in that: The paper-plastic packaging film also includes a glue coating layer; The adhesive coating layer is coated under the inner heat-sealing layer (223); The adhesive coating layer includes hot-sealing adhesive or cold-sealing adhesive.

6. The paper-plastic packaging film according to claim 1, characterized in that: The paper layer (100) has a grammage of 60 g / m 2 -100g / m 2 .

7. The paper-plastic packaging film according to claim 6, characterized in that: The paper layer (100) is also coated with varnish.

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