Impermeable slow-release packaging material for alcohol packaging and preparation method of impermeable slow-release packaging material

Abstract

The invention discloses an anti-seepage slow-release packaging material for alcohol packaging and a preparation method of the anti-seepage slow-release packaging material. The packaging material comprises a straight-hole PET film layer, a nylon paper layer or a waterproof and oilproof paper layer and a modified PE / PP composite film layer, the straight hole PET film layer is attached to the top face of the nylon paper layer or the waterproof and oilproof paper layer, and the modified PE / PP composite film layer is attached to the bottom face of the nylon paper layer or the waterproof and oilproof paper layer. A plurality of straight through holes are formed in the straight hole PET film layer; the modified PE / PP composite film layer is prepared from linear metallocene polyethylene, low-density polyethylene, film blowing homopolymer polypropylene, ethylene-vinyl acetate copolymer resin, aramid nano-fibers, a nano heavy calcium carbonate foaming agent and the like in percentage by mass. The anti-seepage slow-release packaging material for alcohol packaging is easy to seal and resistant to tearing, no liquid seeps from the edge sealing and the surface, and the alcohol release amount is controllable, and an alcohol bag made of the anti-seepage slow-release packaging material for alcohol packaging is small in smell in food packaging, does not affect the flavor of food and is free of pollution to food.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging films, and particularly relates to an anti-seepage and slow-release packaging material for alcohol packaging and a preparation method thereof. Background Art

[0002] Alcohol-based externally controlled preservatives are widely used in the anti-mold preservation of bakery foods such as bread and cakes. Current alcohol-based externally controlled preservatives include alcohol tablets (cards), powdered alcohol packages, cotton block-shaped alcohol packages, and colloidal alcohol packages. Alcohol tablets (cards) are obtained by first laminating both sides of a paper sheet (card), then adsorbing alcohol. Powdered alcohol packages are made by first adsorbing alcohol with silica white, silica gel powder, vermiculite, etc. to obtain alcohol powder, and then packaging the alcohol powder into bags through a packaging machine. Cotton block-shaped alcohol packages are made by first adsorbing alcohol liquid or colloidal alcohol with absorbent cotton, and then packaging it into bags through a packaging machine. Colloidal alcohol packages are made by first curing alcohol into a colloid with a curing agent, and then packaging it into bags through a packaging machine. Currently, the problems of the above four types of alcohol package products are that the release rate of alcohol is uncontrollable. If the release rate is too fast, it will cause the food to taste bitter and affect the food flavor. Colloidal alcohol packages also have problems such as poor storage resistance, too fast exudation of the colloidal liquid after storage, and inconvenience in use on the food packaging production line. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention aims to provide an anti-seepage and slow-release packaging material for alcohol packaging and a preparation method thereof.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An anti-seepage and slow-release packaging material for alcohol packaging, characterized in that it comprises a straight-hole PET film layer, a Nikko paper layer or a waterproof and oil-proof paper layer, and a modified PE / PP composite film layer;

[0006] The straight-hole PET film layer is attached to the top surface of the Nikko paper layer or the waterproof and oil-proof paper layer, and the modified PE / PP composite film layer is attached to the bottom surface of the Nikko paper layer or the waterproof and oil-proof paper layer;

[0007] The modified PE / PP composite film layer is made by extruding and blowing linear metallocene polyethylene M-LLDPE, low-density polyethylene LDPE, blown film homopolymer polypropylene, ethylene-vinyl acetate copolymer resin EVA, aramid nanofibers ANFs, and nano-calcium carbonate foaming agent using a blown film machine.

[0008] Furthermore, a plurality of straight through holes are provided on the straight-hole PET film layer. The aperture of the straight through holes is 0.38 - 0.45 mm, the hole pitch between any two adjacent straight through holes is 1 - 2 mm, and the air permeability of the straight-hole PET film layer is 100 ml of gas passing time of 2 - 10 seconds.

[0009] Further, the Nichrome paper layer is a flat Nichrome paper with a weight of 15 - 40 g / m²; the waterproof and oil-proof paper layer is a waterproof and oil-proof paper with a weight of 28 - 40 g / m².

[0010] Further, a first adhesive layer is provided between the straight-hole PET film layer and the Nichrome paper layer or the waterproof and oil-proof paper layer; a second adhesive layer is provided between the Nichrome paper layer or the waterproof and oil-proof paper layer and the modified PE / PP composite film layer.

[0011] Even further, the first adhesive layer and the second adhesive layer are alcohol-resistant permeation glues.

[0012] Further, a printing layer is provided on the bottom surface of the straight-hole PET film layer; the printing layer is attached to the top surface of the Nichrome paper layer or the waterproof and oil-proof paper layer.

[0013] The present invention also provides a preparation method of the above-mentioned anti-seepage and slow-release packaging material for alcohol packaging, which includes the following steps:

[0014] S1. Prepare the modified PE / PP composite film layer: The material of the modified PE / PP composite film layer includes three layers: an outer layer, a middle layer, and an inner layer; by mass percentage,

[0015] The outer layer material contains 31 - 42% of linear metallocene polyethylene M-LLDPE, 11% of low-density polyethylene LDPE, 6% of blown film homopolymer polypropylene, 28% of ethylene-vinyl acetate copolymer resin EVA, 5 - 14% of aramid nanofibers ANFs, and 5 - 10% of nano heavy calcium carbonate foaming agent;

[0016] The middle layer material contains 34 - 46% of linear metallocene polyethylene M-LLDPE, 13% of low-density polyethylene LDPE, 6% of blown film homopolymer polypropylene, 25% of ethylene-vinyl acetate copolymer resin EVA, 5 - 14% of aramid nanofibers, and 5 - 8% of nano heavy calcium carbonate foaming agent;

[0017] The inner layer material contains 40 - 50% of linear metallocene polyethylene M-LLDPE, 10% of low-density polyethylene LDPE, 2% of blown film homopolymer polypropylene, 25% of ethylene-vinyl acetate copolymer resin EVA, 6 - 13% of aramid nanofibers ANFs, and 7 - 10% of nano heavy calcium carbonate foaming agent;

[0018] Use a three-layer co-extrusion upward traction rotary blown film machine, and add outer layer materials, middle layer materials and inner layer materials into three groups of main machines respectively. The main machine temperature of the outer layer materials is 165-175 °C, the main machine temperature of the middle layer materials is 165-175 °C, and the main machine temperature of the inner layer materials is 175-180 °C; after the three groups of main machines are heated to the set temperature, after reaching a blow-up ratio of 1:5 through the three-layer co-extrusion die head, perform uniform stretching in the longitudinal and transverse directions, cool and form to obtain a modified PE / PP composite film layer, and wind it up for standby;

[0019] S2. Prepare an anti-seepage and slow-release packaging material for alcohol packaging:

[0020] S2.1. First, obtain a printed layer by printing on the bottom of the straight-hole PET film layer, and then laminate the bottom surface of the straight-hole PET film layer with the printed layer with a Nicole paper layer or a waterproof and oil-proof paper layer to obtain a composite film;

[0021] S2.2. Laminate the bottom surface of the composite film obtained in step S2.1 with the modified PE / PP composite film layer to obtain an anti-seepage and slow-release packaging material for alcohol packaging.

[0022] Furthermore, in step S2.1, first coat a first adhesive layer on the bottom surface of the straight-hole PET film layer with the printed layer, and then laminate it with a Nicole paper layer or a waterproof and oil-proof paper layer to obtain a composite film; in step S2.2, coat a second adhesive layer on the side of the Nicole paper layer or the waterproof and oil-proof paper layer in the composite film obtained in step S2.1, and then laminate it with the modified PE / PP composite film layer.

[0023] Still further, in step S2.1, place the straight-hole PET film layer with the printed layer in a dry laminating machine, and use a 120-mesh gravure roll to coat a first adhesive layer on the bottom surface of the straight-hole PET film layer with the printed layer; in the dry laminating machine, the temperature of the rubber kneader is 75-100 °C, the temperature of the coating roller is 80-100 °C, the vehicle speed is 150-280 m / min, the coating amount is 2-5 g / m², and after lamination, cure at 55 °C for 72 hours to obtain a composite film, and the air permeability of the composite film is 100 ml of gas passing through in 50-200 seconds;

[0024] In step S2.2, use a solventless laminating machine to laminate the composite film with the modified PE / PP composite film layer; in the solventless laminating machine, the temperature of the rubber kneader is 80-100 °C, the temperature of the coating roller is 80-100 °C, the vehicle speed is 150-300 m / min, the coating amount is 2-4 g / m², and after lamination, cure at 40-70 °C for 60 hours to obtain an anti-seepage and slow-release packaging material for alcohol packaging; the alcohol vapor transmission rate of the anti-seepage and slow-release packaging material for alcohol packaging is 29 to 80 g / m²*24h at 30 °C.

[0025] The beneficial effects of the present invention are as follows: The alcohol vapor transmission rate of the anti-seepage and slow-release packaging material for alcohol of the present invention is stably adjustable at 29 - 80 g / m²·24h (30°C), the sealing strength can reach 35 - 47 N / 15 mm after edge sealing and fusion, the transverse tear strength can reach 15 N, and the longitudinal tear strength can reach 17 N. It has the advantages of high sealing strength, easy sealing, tear resistance, no liquid leakage at the edge and on the surface, and controllable alcohol release amount. The alcohol package made of this anti-seepage and slow-release packaging material for alcohol has a small odor in food packaging, does not affect the flavor of food, and is pollution-free to food. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the composite structure of the anti-seepage and slow-release packaging material for alcohol in Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention will be further described below with reference to the accompanying drawings. It should be noted that this embodiment is based on the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to this embodiment.

[0028] Embodiment 1

[0029] This embodiment provides an anti-seepage and slow-release packaging material for alcohol, as Figure 1 shown, from top to bottom, there are a straight-hole PET film layer 1, a first adhesive layer 2, a Nikko paper layer 3, a second adhesive layer 4, and a modified PE / PP composite film layer 5 in sequence; a plurality of straight through-holes are provided on the straight-hole PET film layer 1.

[0030] In this embodiment, the modified PE / PP composite film layer is made by mixing linear metallocene polyethylene M-LLDPE, low-density polyethylene LDPE, blown film homopolymer polypropylene, ethylene-vinyl acetate copolymer resin EVA, aramid nanofibers ANFs, and nano heavy calcium carbonate foaming agent, and then extruding and blowing with a blown film machine.

[0031] The modified PE / PP composite film obtained in this embodiment has a uniform thickness and has a good heat-sealing effect when used on a packaging machine at a machine speed of 100 - 110 sheets / min and a transverse sealing temperature in the range of 100 - 180°C. In this embodiment, the thickness of the modified PE / PP composite film layer can be 20 - 30 microns. Optionally, the thickness of the modified PE / PP composite film layer can be 30 microns.

[0032] In this embodiment, the thickness of the straight-hole PET film layer can be 10 - 14 microns, the aperture of the straight-through holes can be 0.38 - 0.45 mm, the hole pitch between any two adjacent straight-through holes can be 1 - 2 mm, and the air permeability of the straight-hole PET film layer is such that the time for 100 ml of gas to pass through is 2 - 10 seconds. Optionally, when the thickness of the straight-hole PET film layer is 12 microns, the aperture of the straight-through holes is 0.4 mm, the hole pitch between any two adjacent straight-through holes is 1.5 mm, and the air permeability of the straight-hole PET film layer is such that the time for 100 ml of gas to pass through is 8 seconds.

[0033] In this embodiment, the Nikko paper layer can be a flat Nikko paper with a weight of 15 - 40 g / m² and a thickness of 30 - 50 microns. Optionally, the Nikko paper layer can be a flat Nikko paper with a weight of 30 g / m² and a thickness of 35 microns.

[0034] In this embodiment, the Nikko paper layer can be replaced with a waterproof and oil-proof paper layer, and the waterproof and oil-proof paper layer can be 28 - 40 g / m² with a thickness of 30 - 50 microns. Optionally, the waterproof and oil-proof paper layer can be 36 g / m² with a thickness of 35 microns.

[0035] In this embodiment, both the first adhesive layer 2 and the second adhesive layer 4 are made of a two-component polyurethane adhesive layer, such as Henkel alcohol-resistant two-component polyurethane glue.

[0036] This embodiment also provides a preparation method for the above-mentioned anti-seepage and slow-release packaging material for alcohol packaging, including the following steps:

[0037] S1. Prepare a modified PE / PP composite film layer: The material of the modified PE / PP composite film layer includes three layers: an outer layer, a middle layer, and an inner layer; by mass percentage,

[0038] The outer layer material contains 31 - 42% linear metallocene polyethylene M-LLDPE, 11% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 28% ethylene-vinyl acetate copolymer resin EVA, 5 - 14% aramid nanofibers ANFs, and 5 - 10% nano heavy calcium carbonate foaming agent;

[0039] The middle layer material contains 34 - 46% linear metallocene polyethylene M-LLDPE, 13% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 5 - 14% aramid nanofibers, and 5 - 8% nano heavy calcium carbonate foaming agent;

[0040] The inner layer material contains 40-50% linear metallocene polyethylene M-LLDPE, 10% low-density polyethylene LDPE, 2% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 6-13% aramid nanofibers ANFs, and 7-10% nano heavy calcium carbonate foaming agent;

[0041] A three-layer co-extrusion up-drawing rotary blown film machine is used. The outer layer material, middle layer material, and inner layer material are respectively added into three groups of main machines. The main machine temperature of the outer layer material is 165-175°C, the main machine temperature of the middle layer material is 165-175°C, and the main machine temperature of the inner layer material is 175-180°C. After the three groups of main machines are heated to the set temperature, through the three-layer co-extrusion die head, after reaching a blow-up ratio of 1:5, uniform stretching is carried out longitudinally and transversely, and then cooled and formed to obtain a modified PE / PP composite film layer, which is wound up for standby;

[0042] S2. Prepare an anti-seepage and slow-release packaging material for alcohol packaging:

[0043] S2.1. First, a printing layer is obtained by printing on the bottom of the straight-hole PET film layer. Then, the bottom surface of the straight-hole PET film layer with the printing layer is compounded with a Nikko paper layer or a waterproof and oil-proof paper layer to obtain a composite film;

[0044] S2.2. The bottom surface of the composite film obtained in step S2.1 is compounded with the modified PE / PP composite film layer to obtain an anti-seepage and slow-release packaging material for alcohol packaging.

[0045] Furthermore, in step S2.1, a first adhesive layer is first coated on the bottom surface of the straight-hole PET film layer with the printing layer, and then compounded with a Nikko paper layer or a waterproof and oil-proof paper layer to obtain a composite film; in step S2.2, after a second adhesive layer is coated on one side of the Nikko paper layer or the waterproof and oil-proof paper layer in the composite film obtained in step S2.1, it is compounded with the modified PE / PP composite film layer.

[0046] Still further, in step S2.1, the straight-hole PET film layer with the printing layer is placed in a dry laminator, and a first adhesive layer is coated on the bottom surface of the straight-hole PET film layer with the printing layer by using a 120-mesh gravure roll. In the dry laminator, the temperature of the rubber kneader is 75-100°C, the temperature of the coating roll is 80-100°C, the vehicle speed is 150-280 m / min, the coating amount is 2-5 g / m², and after compounding, it is cured at 55°C for 72 hours to obtain a composite film. The air permeability of the composite film is 100 ml of gas passing through in 50-200 seconds;

[0047] In step S2.2, the composite film and the modified PE / PP composite film layer are composited by a solvent-free composite machine; in the solvent-free composite machine, the temperature of the rubber mixer is 80-100°C, the temperature of the glue roller is 80-100°C, the vehicle speed is 150-300 m / min, the glue amount is 2-4 g / m2, and after composite, it is aged at 40-70°C for 60 hours to obtain an anti-seepage sustained-release packaging material for alcohol packaging; the alcohol vapor permeability of the anti-seepage sustained-release packaging material for alcohol packaging is 29 to 80 g / m2*24h at 30°C.

[0048] In this embodiment, a printing layer may also be provided on the bottom surface of the straight-pore PET film layer; the printing layer is attached to the top surface of the nico paper layer or the waterproof and oil-proof paper layer.

[0049] In the above-mentioned anti-seepage sustained-release packaging material for alcohol packaging, the straight-pore PET film layer can be resistant to high temperatures to avoid deformation of the film during machine sealing, and a printing layer can be provided on the other hand. The modified PE / PP composite film is used as an anti-seepage heat-sealing layer. The nico paper layer or the waterproof and oil-proof paper layer increases the tear resistance of the anti-seepage sustained-release packaging material for alcohol packaging while increasing air permeability.

[0050] The alcohol vapor permeability of the anti-seepage sustained-release packaging material for alcohol packaging provided in this embodiment is stably adjustable at 29-80 g / m2*24h (30°C), the sealing strength can reach 35-47N / 15 mm after edge sealing and fusion, the transverse tear strength can reach 15N, and the longitudinal tear strength can reach 17N. It has the advantages of high sealing strength, easy sealing, tear resistance, no liquid seepage from the edge sealing and surface, and controllable alcohol release. The alcohol package made using the anti-seepage sustained-release packaging material for alcohol packaging has little odor in food packaging, does not affect the flavor of food, and does not pollute food.

[0051] Example 2

[0052] This embodiment provides a method for preparing the impermeable sustained-release packaging material for alcohol packaging described in Embodiment 1, comprising the following steps:

[0053] S1. Material preparation:

[0054] (1) Preparation of straight hole PET film layer: Use packaging film piercing equipment to pierce straight through holes on the PET film, and after passing the test, the straight hole PET film layer is obtained and rolled up for use;

[0055] (2) Preparation of modified PE / PP composite film layer:

[0056] The materials of the modified PE / PP composite film layer include an outer layer, a middle layer, and an inner layer; by mass percentage,

[0057] The outer layer material contains 36% linear metallocene polyethylene M-LLDPE, 11% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 28% ethylene-vinyl acetate copolymer resin EVA, 9% aramid nanofibers ANFs, and 10% nano heavy calcium carbonate foaming agent;

[0058] The middle layer material contains 40% linear metallocene polyethylene M-LLDPE, 13% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 8% aramid nanofibers ANFs, and 8% nano heavy calcium carbonate foaming agent;

[0059] The inner layer material contains 45% linear metallocene polyethylene M-LLDPE, 10% low-density polyethylene LDPE, 2% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 8% aramid nanofibers ANFs, and 10% nano heavy calcium carbonate foaming agent;

[0060] Using a three-layer coextrusion up-drawing rotary blown film machine, add the outer layer material, middle layer material, and inner layer material into three groups of main machines respectively. The main machine temperature of the outer layer material is 170 °C, the main machine temperature of the middle layer material is 170 °C, and the main machine temperature of the inner layer material is 180 °C; after the three groups of main machines are heated to the set temperature, after reaching a blow-up ratio of 1:5 through the three-layer coextrusion die head, perform uniform stretching in the longitudinal and transverse directions, and cool and form through the machine cooling system to obtain a modified PE / PP composite film layer, and wind it up for standby;

[0061] The thickness of the blown modified PE / PP composite film layer is 30 microns, with uniform thickness. It is used on a packaging machine, and the machine speed is 100 - 110 sheets / min. The heat sealing effect is good within the range of the transverse sealing temperature of 100 - 180 °C.

[0062] S2. Prepare an anti-seepage and slow-release packaging material for alcohol packaging:

[0063] S2.1. Place the straight-hole PET film layer in a dry laminating machine, and use a 120-mesh gravure roll to coat a first adhesive layer on the side of the straight-hole PET film layer with a printing layer, and perform lamination with its Nicol paper layer to obtain a composite film; in the dry laminating machine, the temperature of the rubber kneader is 95 °C, the temperature of the coating roll is 90 °C, the vehicle speed is 200 m / min, the coating amount is 4 g / m², and after lamination, it is cured at 55 °C for 72 hours to obtain a composite film, and the gas permeability of the composite film is 100 ml of gas passing through in 150 seconds.

[0064] S2.2. Place the composite film obtained in step S2.1 in a solventless laminator. Coat one side of the Niko paper layer in the composite film with a second adhesive layer using the solventless laminator and then laminate it with the modified PE / PP composite film layer. In the solventless laminator, the temperature of the rubber kneader is 95 °C, the temperature of the coating roller is 90 °C, the vehicle speed is 200 m / min, the coating amount is 4 g / m², and it is cured at 65 °C for 60 hours after lamination to obtain an anti-seepage and slow-release packaging material for alcohol packaging.

[0065] In this embodiment, the thickness of the straight-hole PET film layer is 12 μm, the aperture of the straight through-hole is 0.4 mm, the hole pitch between any two adjacent straight through-holes is 1.5 mm, and the air permeability of the straight-hole PET film layer is 100 ml of gas passing through in 8 seconds. The Niko paper layer is a flat Niko paper with a weight of 30 g / m² and a thickness of 35 μm.

[0066] The alcohol vapor transmission rate of the anti-seepage and slow-release packaging material for alcohol packaging obtained in this embodiment is 55 g / m²·24h at 30 °C. The sealing strength after edge fusion is 40 N / 15 mm, the transverse tear strength is 15 N, and the longitudinal tear strength is 15 N. It is qualified after inspection as an anti-seepage and slow-release packaging material for alcohol packaging.

[0067] Example 3

[0068] This embodiment also provides a preparation method of the anti-seepage and slow-release packaging material for alcohol packaging described in Example 1. The main difference in the preparation method from Example 2 is that in the preparation of the modified PE / PP composite film layer in this embodiment, the material ratios of the outer layer, middle layer, and inner layer are as follows:

[0069] The outer layer material contains 31% linear metallocene polyethylene M-LLDPE, 11% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 28% ethylene-vinyl acetate copolymer resin EVA, 14% aramid nanofibers ANFs, and 10% nano heavy calcium carbonate foaming agent;

[0070] The middle layer material contains 34% linear metallocene polyethylene M-LLDPE, 13% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 14% aramid nanofibers ANFs, and 8% nano heavy calcium carbonate foaming agent;

[0071] The inner layer material contains 40% linear metallocene polyethylene M-LLDPE, 10% low-density polyethylene LDPE, 2% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 13% aramid nanofibers ANFs, and 10% nano heavy calcium carbonate foaming agent.

[0072] The alcohol vapor transmission rate of the final anti-seepage and slow-release packaging material for alcohol is 80 g / m²·24h (30°C). After edge sealing and fusion, the sealing strength is 35 N / 15 mm, the transverse tear strength is 10 N, and the longitudinal tear strength is 6 N. Judging from the test data, the alcohol vapor transmission rate of the obtained anti-seepage and slow-release packaging material for alcohol increases, while the heat sealing strength decreases. It can be seen that when blowing the modified PE / PP composite film, increasing the content of ANFs and decreasing the content of M-LLDPE can increase the alcohol vapor transmission rate, but the heat sealing strength of the packaging will decrease.

[0073] Example 4

[0074] This example also provides a preparation method of the anti-seepage and slow-release packaging material for alcohol described in Example 1. The main difference in the preparation method from Example 2 is that in the preparation of the modified PE / PP composite film layer in this example, the material ratios of the outer layer, middle layer, and inner layer are as follows:

[0075] The outer layer material contains 42% linear metallocene polyethylene M-LLDPE, 11% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 28% ethylene-vinyl acetate copolymer resin EVA, 5% aramid nanofibers ANFs, and 8% nano heavy calcium carbonate foaming agent;

[0076] The middle layer material contains 46% linear metallocene polyethylene M-LLDPE, 13% low-density polyethylene LDPE, 6% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 5% aramid nanofibers ANFs, and 5% nano heavy calcium carbonate foaming agent;

[0077] The inner layer material contains 50% linear metallocene polyethylene M-LLDPE, 10% low-density polyethylene LDPE, 2% blown film homopolymer polypropylene, 25% ethylene-vinyl acetate copolymer resin EVA, 6% aramid nanofibers ANFs, and 7% nano heavy calcium carbonate foaming agent.

[0078] The alcohol vapor transmission rate of the anti-seepage and slow-release packaging material for alcohol obtained in this example is 29 g / m²·24h (30°C). After edge sealing and fusion, the sealing strength is 47 N / 15 mm, the transverse tear strength is 15 N, and the longitudinal tear strength is 17 N. Judging from the test data, the alcohol vapor transmission rate of the obtained composite film decreases, while the heat sealing strength increases. It can be seen that when blowing the modified PE / PP composite film, decreasing the content of ANFs and increasing the content of M-LLDPE can increase the heat sealing strength, but the alcohol vapor transmission rate will decrease.

[0079] Those skilled in the art can make various corresponding changes and deformations based on the above technical solutions and concepts, and all such changes and deformations should be included within the protection scope of the claims of the present invention.

Claims

1. An impermeable sustained-release packaging material for alcohol packaging, characterized in that: It includes a straight-pore PET film layer, a nico paper layer or a waterproof and oil-proof paper layer, and a modified PE / PP composite film layer; The straight-pore PET film layer is attached to the top surface of the nico paper layer or the waterproof and oil-proof paper layer, and the modified PE / PP composite film layer is attached to the bottom surface of the nico paper layer or the waterproof and oil-proof paper layer; The modified PE / PP composite film layer is made of linear metallocene polyethylene M-LLDPE, low-density polyethylene LDPE, film-blowing homopolymer-grade polypropylene, ethylene-vinyl acetate copolymer resin EVA, aramid nanofibers ANFs and nano-heavy calcium carbonate foaming agent by extruding a film-blowing machine.

2. The anti-seepage sustained-release packaging material for alcohol packaging according to claim 1, characterized in that: The straight-hole PET film layer is provided with a plurality of straight-through holes, the aperture of the straight-through holes is 0.38-0.45 mm, the hole distance between any two adjacent straight-through holes is 1-2 mm, and the air permeability of the straight-hole PET film layer is 2-10 seconds for 100 ml of gas to pass through.

3. The anti-seepage sustained-release packaging material for alcohol packaging according to claim 1, characterized in that: The nico paper layer is a flat nico paper with a weight of 15-40 g / m2; and the waterproof and oil-proof paper layer is a waterproof and oil-proof paper with a weight of 28-40 g / m2.

4. The anti-seepage sustained-release packaging material for alcohol packaging according to claim 1, characterized in that: A first adhesive layer is provided between the straight-pore PET film layer and the nico paper layer or the waterproof and oil-proof paper layer; a second adhesive layer is provided between the nico paper layer or the waterproof and oil-proof paper layer and the modified PE / PP composite film layer.

5. The anti-seepage sustained-release packaging material for alcohol packaging according to claim 4, characterized in that: The first adhesive layer and the second adhesive layer are alcohol-resistant glue.

6. The anti-seepage sustained-release packaging material for alcohol packaging according to claim 1, characterized in that: A printing layer is arranged on the bottom surface of the straight-hole PET film layer; the printing layer is attached to the top surface of the nico paper layer or the waterproof and oil-proof paper layer.

7. A method for preparing the impermeable sustained-release packaging material for alcohol packaging according to any one of claims 1 to 6, characterized in that: The steps include: S1. Preparation of modified PE / PP composite film layer: The materials of the modified PE / PP composite film layer include an outer layer, a middle layer and an inner layer; calculated by mass percentage, The outer layer material contains 31-42% of linear metallocene polyethylene M-LLDPE, 11% of low-density polyethylene LDPE, 6% of blown film homopolymer grade polypropylene, 28% of ethylene-vinyl acetate copolymer resin EVA, 5-14% of aramid nanofiber ANFs, and 5-10% of nano heavy calcium carbonate foaming agent; The middle layer material contains 34-46% of linear metallocene polyethylene M-LLDPE, 13% of low-density polyethylene LDPE, 6% of blown film homopolymer grade polypropylene, 25% of ethylene-vinyl acetate copolymer resin EVA, 5-14% of aramid nanofiber and 5-8% of nano heavy calcium carbonate foaming agent; The inner layer material contains 40-50% of linear metallocene polyethylene M-LLDPE, 10% of low-density polyethylene LDPE, 2% of blown film homopolymer grade polypropylene, 25% of ethylene-vinyl acetate copolymer resin EVA, 6-13% of aramid nanofiber ANFs, and 7-10% of nano heavy calcium carbonate foaming agent; A three-layer co-extrusion upper traction rotary film blowing machine is used to add outer layer materials, middle layer materials and inner layer materials into three groups of main machines respectively. The main machine temperature of the outer layer material is 165-175℃, the main machine temperature of the middle layer material is 165-175℃, and the main machine temperature of the inner layer material is 175-180℃; after the three groups of main machines are heated to the set temperature, they pass through the three-layer co-extrusion die head to reach a blowing ratio of 1:5, and then they are uniformly stretched in the longitudinal and transverse directions, cooled and formed to obtain a modified PE / PP composite film layer, which is rolled up for standby use; S2. Preparation of impermeable and sustained-release packaging materials for alcohol packaging: S2.1, pre-printing a printed layer on the bottom of the straight-pore PET film layer, and then laminating the bottom surface of the straight-pore PET film layer provided with the printed layer with a nico paper layer or a waterproof and oil-proof paper layer to obtain a composite film; S2.

2. Compounding the bottom surface of the composite film obtained in step S2.1 with the modified PE / PP composite film layer to obtain an impermeable and sustained-release packaging material for alcohol packaging.

8. The preparation method according to claim 7, characterized in that: In step S2.1, a first adhesive layer is firstly coated on the bottom surface of the straight-pore PET film layer provided with the printing layer, and then compounded with the nico paper layer or the waterproof and oil-proof paper layer to obtain a composite film; In step S2.2, a second adhesive layer is applied to one side of the nicotinic paper layer or the waterproof and oil-proof paper layer in the composite film obtained in step S2.1 and then composited with the modified PE / PP composite film layer.

9. The preparation method according to claim 8, characterized in that In step S2.1, the straight hole PET film layer provided with the printing layer is placed in a dry laminating machine, and a first glue layer is applied to the bottom surface of the straight hole PET film layer provided with the printing layer by using a 120-mesh anilox roller; in the dry laminating machine, the temperature of the rubber mixer is 75-100° C., the temperature of the glue roller is 80-100° C., the speed is 150-280 m / min, the glue amount is 2-5 g / m2, and after laminating, the composite film is aged at 55° C. for 72 hours to obtain a composite film, and the air permeability of the composite film is 50-200 seconds for 100 ml of gas to pass through; In step S2.2, the composite film and the modified PE / PP composite film layer are composited by a solvent-free composite machine; in the solvent-free composite machine, the temperature of the rubber mixer is 80-100°C, the temperature of the glue roller is 80-100°C, the vehicle speed is 150-300 m / min, the glue amount is 2-4 g / m2, and after composite, it is aged at 40-70°C for 60 hours to obtain an anti-seepage sustained-release packaging material for alcohol packaging; the alcohol vapor permeability of the anti-seepage sustained-release packaging material for alcohol packaging is 29 to 80 g / m2*24h at 30°C.

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