A method for preparing aluminum foil packaging material and its application

Abstract

The present invention provides a method for preparing an aluminum foil packaging material and its application, which relates to the field of aluminum foil packaging technology. The method includes preparing a core layer cast plate, a barrier layer cast plate, and a functional layer cast plate; stacking the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate in sequence to form a composite aluminum foil plate, hot-rolling the composite aluminum foil plate, and then conducting a preliminary aluminum foil optimal thickness determination test to determine the preliminary optimal thickness of the aluminum foil, and forming a preliminary aluminum foil after cold rolling; surface-modifying the preliminary aluminum foil and spraying a layer of antibacterial coating to form a finished aluminum foil. The present invention adopts a three-layer structural design, in which the core layer provides basic strength, the barrier layer provides aluminum foil barrier properties, including water vapor barrier properties and oxygen barrier properties, and the functional layer provides antibacterial, light barrier, and water vapor barrier functions, thereby improving the barrier properties of traditional aluminum foil and effectively blocking the penetration of water vapor, oxygen, and light. The present invention is used for packaging freeze-dried products to ensure that the freeze-dried products are not easily damp in the aluminum foil material.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum foil packaging, and in particular relates to a method for preparing an aluminum foil packaging material and application thereof. Background Art

[0002] Aluminum has high barrier properties and can effectively block oxygen, moisture, and light, which is important for preserving food and medicine. At the same time, due to its good ductility, it can be easily processed into different shapes and thicknesses to meet various packaging needs. Therefore, aluminum foil has become a core material in the high-end packaging field due to its unique physical and chemical properties.

[0003] Freeze-dried foods (such as high-end ingredients such as matsutake mushrooms) have become an important category in the field of healthy foods because they retain their original nutrients and flavor characteristics through a low-temperature dehydration process. Although traditional freeze-drying technology can reduce the water content to below 1%, it faces the problem of water backflow caused by environmental humidity, oxygen penetration and light during storage. When the moisture content rises to above 3%, the product is prone to browning, aroma loss and texture softening, resulting in deterioration of color, flavor and aroma. Traditional processes mostly use single-layer homogeneous aluminum rolling, which has insufficient barrier properties and cannot effectively isolate the penetration of water vapor, oxygen and light, making it difficult to meet the packaging needs of high-end freeze-dried foods. In addition, conventional aluminum foil preparation processes cannot carry out targeted customized production of aluminum foil based on the actual use needs of the packaged products, resulting in insufficient adaptability. Summary of the Invention

[0004] The present invention provides a method for preparing an aluminum foil packaging material and application thereof, to solve at least one of the technical problems raised above.

[0005] To solve the above technical problems, the present invention discloses a method for preparing an aluminum foil packaging material and its application, the method comprising the following steps:

[0006] S1. preparing a core layer ingot, a barrier layer ingot, and a functional layer ingot, and hot rolling the core layer ingot, the barrier layer ingot, and the functional layer ingot to form a core layer cast plate, a barrier layer cast plate, and a functional layer cast plate, respectively;

[0007] S2. Stacking the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate in sequence, securing them with a fixture, and then placing them into an annealing furnace to combine the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate into one, forming a composite aluminum foil plate; hot rolling the composite aluminum foil plate; and performing a preliminary test to determine an optimal thickness of the aluminum foil after the hot rolling is completed. Based on the test results, a preliminary optimal thickness of the aluminum foil is determined. Cold rolling is performed based on the preliminary optimal thickness of the aluminum foil to finally form a preliminary aluminum foil.

[0008] The preliminary aluminum foil includes a core layer, a barrier layer and a functional layer. The core layer is used to provide basic strength, the barrier layer is used to provide aluminum foil barrier properties, including water vapor barrier properties and oxygen barrier properties, and the functional layer is used to provide antibacterial, light barrier and water vapor barrier functions;

[0009] S3, using a plasma treatment device to perform surface modification on the preliminary aluminum foil, and spraying a layer of antibacterial coating on the surface of the surface-modified preliminary aluminum foil;

[0010] S4. Annealing the preliminary aluminum foil sprayed with the antibacterial coating to form finished aluminum foil. Sampling quality inspection is carried out on each batch of finished aluminum foil. After passing the quality inspection, the finished aluminum foil is cut and packaged.

[0011] Preferably, step S1 includes the following steps:

[0012] S11, adding the aluminum foil core layer raw material, the barrier layer raw material, and the functional layer raw material into a melting furnace according to the composition ratio for melting, wherein the melting temperatures of the aluminum foil core layer raw material, the barrier layer raw material, and the functional layer raw material are 700-800° C., 700-750° C., and 750-800° C., respectively;

[0013] S12, pouring the melted core layer raw material, barrier layer raw material, and functional layer raw material into a die casting machine and cooling them to form a core layer ingot, a barrier layer ingot, and a functional layer ingot;

[0014] S13, placing the core layer ingot, the barrier layer ingot, and the functional layer ingot on a sawing machine for cutting, and performing milling on the cut surfaces to ensure a smooth surface;

[0015] S14, placing the cut core layer ingot, barrier layer ingot, and functional layer ingot into an annealing furnace for homogenization treatment;

[0016] S15, hot rolling the core layer ingot, barrier layer ingot and functional layer ingot after homogenization treatment to form core layer cast plate, barrier layer cast plate and functional layer cast plate, with the hot rolling temperature being 400-450°C.

[0017] Preferably, the core layer raw material composition ratio is: aluminum 99.3%, iron 0.1%, copper 0.1%, magnesium 0.15%, zirconium 0.05%, silicon 0.1%, titanium 0.1%, graphene oxide 0.05%, carbon nanotubes 0.05%;

[0018] Barrier layer raw material composition ratio: aluminum 99%, iron 0.05%, copper 0.05%, magnesium 0.05%, silicon 0.05%, titanium 0.05%, chromium 0.2%, yttrium 0.1%, tin 0.1%, nano-silicon dioxide 0.3%, graphene 0.05%;

[0019] The proportion of raw materials in the functional layer is as follows: 99.1% aluminum, 0.05% iron, 0.03% copper, 0.02% magnesium, 0.05% silicon, 0.05% titanium, 0.3% polyvinylidene chloride, 0.2% ethylene-vinyl alcohol copolymer, 0.1% silver-zinc composite nanoparticles, and 0.1% titanium dioxide nanotubes.

[0020] Preferably, the thicknesses of the core layer cast plate, the barrier layer cast plate and the functional layer cast plate are 10-20 mm, 8-15 mm and 10-18 mm respectively;

[0021] The thickness of hot-rolled composite aluminum foil is 8-10mm.

[0022] Preferably, after hot rolling is completed, a preliminary test is performed to determine the optimal thickness of the aluminum foil. The preliminary optimal thickness of the aluminum foil is determined based on the test results, including:

[0023] S21, cold rolling the hot-rolled composite aluminum foil sheet according to different cold rolling reduction ratios to prepare a plurality of cold-rolled samples, measuring the thickness of each cold-rolled sample and recording the thickness value;

[0024] S22. Prepare each cold-rolled sample into a standard specimen according to the standard requirements of the tensile test, perform a tensile test on each cold-rolled sample using a universal material testing machine, and record the tensile strength, yield strength, and elongation data of the cold-rolled sample during the test;

[0025] S23. Generate a corresponding performance matrix based on the tensile strength, yield strength, and elongation data of the cold-rolled samples during the test; determine three alternative thicknesses based on the performance matrix of each cold-rolled sample and a preset performance matrix; customize three cold-rolled samples based on the alternative thicknesses; conduct a barrier property test on the cold-rolled samples; and determine a preliminary optimal thickness of the aluminum foil based on the test results of the barrier property test.

[0026] Preferably, step S23 includes:

[0027] S231. Generate a tensile strength curve, a yield strength curve, and an elongation curve based on the tensile strength, yield strength, and elongation data of the cold-rolled sample during the test;

[0028] S232, extracting key eigenvalues ​​of the tensile strength curve, the yield strength curve, and the elongation curve; generating a tensile strength eigenvector, a yield strength eigenvector, and an elongation eigenvector based on the key eigenvalues ​​of the tensile strength curve, the yield strength curve, and the elongation curve; and generating a performance matrix corresponding to the cold-rolled sample based on the tensile strength eigenvector, the yield strength eigenvector, and the elongation eigenvector;

[0029] S233. Calculate the proximity between the performance matrix of the cold-rolled sample and the preset performance matrix, use the thicknesses corresponding to the top three cold-rolled samples ranked by proximity between the performance matrix of the cold-rolled sample and the preset performance matrix as alternative thicknesses, customize three cold-rolled samples based on the alternative thicknesses, conduct a barrier property test on the cold-rolled samples, and select the alternative thickness corresponding to the cold-rolled sample with the best barrier property as the preliminary optimal thickness of the aluminum foil.

[0030] Preferably, the closeness between the performance matrix of the cold-rolled sample and the preset performance matrix is ​​calculated:

[0031] in, is the closeness between the performance matrix corresponding to the kth cold-rolled sample and the preset performance matrix, x kij is the value of the i-th row and j-th column in the performance matrix corresponding to the k-th cold-rolled sample, x 0ij is the value of the i-th row and j-th column in the preset performance matrix, a is the total number of rows in the performance matrix, and b is the total number of columns in the performance matrix.

[0032] Preferably, step S3 includes:

[0033] S31, placing the preliminary aluminum foil into a plasma treatment device, setting the gas type to argon or nitrogen, and the treatment time to 30 seconds to 1 minute to increase the surface activity;

[0034] S32. Use a spraying device to evenly spray the antibacterial coating on the surface of the preliminary aluminum foil, and control the coating thickness to be 0.001-0.002 mm, wherein the antibacterial coating uses silver nanoparticles.

[0035] Preferably, during the preparation of each batch of aluminum foil packaging materials, sampling thickness testing is required at the completion of each hot rolling or cold rolling step to inspect and accept the current hot rolling or cold rolling results. The steps are as follows:

[0036] Step 1: Select m hot-rolled or cold-rolled products from the current hot-rolled or cold-rolled products for thickness testing. The thickness testing step is to evenly divide each hot-rolled or cold-rolled product into j testing segments along the length direction, take the midpoint of each testing segment for thickness testing, and obtain the thickness value at the midpoint of each testing segment;

[0037] Step 2: Based on the thickness values ​​at the midpoint of each detection section of the m hot-rolled or cold-rolled products, calculate the thickness qualification assessment value of the current hot-rolled or cold-rolled product:

[0038] Where W is the thickness qualification evaluation value of the product after the current hot rolling or cold rolling, m is the total number of thickness test samples in the product after the current hot rolling or cold rolling, ξ1 is the influence coefficient of thickness accuracy on thickness qualification, n is the number of test sections of the product after the hot rolling or cold rolling, H ij is the thickness value at the midpoint of the jth detection section of the i-th sampled product after hot rolling or cold rolling, H0 is the preset thickness value of the current hot rolling or cold rolling product, and ξ2 is the influence coefficient of thickness uniformity on thickness acceptance;

[0039] If the thickness qualification assessment value of the product after the current hot rolling or cold rolling is greater than the benchmark thickness qualification assessment value, it proves that the current preparation step has passed the acceptance. Otherwise, it proves that the current preparation step has failed the acceptance, and an alarm is issued, and the preparation equipment or preparation method is checked and adjusted in time.

[0040] Preferably, step S4 performs quality inspection on the finished aluminum foil including appearance evaluation, performance evaluation and dimensional conformity evaluation;

[0041] The appearance evaluation includes using image acquisition equipment and a trained aluminum foil surface smoothness evaluation model to perform sampling surface smoothness evaluation on each batch of finished aluminum foil to obtain the surface smoothness evaluation value of each batch of finished aluminum foil;

[0042] The performance evaluation includes sampling and testing the antimicrobial performance, barrier performance and mechanical performance of each batch of finished aluminum foil to obtain the antimicrobial performance evaluation value, barrier performance evaluation value and mechanical performance evaluation value of each batch of finished aluminum foil;

[0043] The dimensional conformity assessment includes sampling thickness testing of each batch of finished aluminum foil and calculating the dimensional conformity assessment value of the current batch of finished aluminum foil based on the thickness test results;

[0044] Based on the surface smoothness evaluation value, antimicrobial performance evaluation value, barrier performance evaluation value, mechanical performance evaluation value, and dimensional conformity evaluation value of each batch of finished aluminum foil, a comprehensive performance evaluation value of each batch of finished aluminum foil is obtained, and quality inspection results are generated based on the comprehensive performance evaluation value of each batch of finished aluminum foil;

[0045] Among them, the comprehensive performance evaluation value of each batch of finished aluminum foil is:

[0046] Among them, ∈ is the comprehensive performance evaluation value of the current batch of finished aluminum foil, Z αβ is the αth evaluation value corresponding to the βth sample in the current batch of finished aluminum foil, γ α is the weight of the αth evaluation value, and y is the total number of samples of the current batch of finished aluminum foil.

[0047] The invention discloses an application of an aluminum foil packaging material. The prepared aluminum foil packaging material is used for packaging freeze-dried products.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The present invention adopts a three-layer structural design, wherein the core layer provides basic strength, the barrier layer provides aluminum foil barrier properties, including water vapor barrier properties and oxygen barrier properties, and the functional layer provides antibacterial, light barrier and water vapor barrier functions, thereby greatly improving the barrier properties of traditional aluminum foil, effectively blocking the penetration of water vapor, oxygen and light, and being able to control the moisture content of the product below 3%, thereby extending the product shelf life by more than 5 times, meeting the packaging requirements of high-end ingredients such as matsutake mushrooms, and retaining the original nutritional components and flavor characteristics of high-end ingredients. The preliminary optimal thickness of the aluminum foil is determined through a preliminary aluminum foil optimal thickness determination test, thereby avoiding the situation where the thickness fluctuation of the finished product often leads to insufficient utilization of the aluminum foil material, resulting in waste of resources or insufficient performance affecting the packaging effect. The optimal thickness of the aluminum foil can be determined based on actual needs to achieve flexible customization of the aluminum foil, ensuring product performance while maximizing cost savings. The antibacterial coating uses silver nanoparticles to effectively inhibit the growth of microorganisms and extend the service life of the aluminum foil. Each batch of finished aluminum foil is sampled and inspected for quality, ensuring the factory quality of the product.

[0050] (2) The core layer of the present invention provides basic strength, the barrier layer enhances barrier performance, the functional layer adds antibacterial function, materials such as nano-silicon dioxide and polyethylene have good environmental adaptability, silver nanoparticles have high antibacterial ability, extend the service life of aluminum foil, and the addition of multiple trace elements improves the corrosion resistance and oxidation resistance of the material;

[0051] (3) The present invention cold-rolls the hot-rolled composite aluminum foil sheet according to different cold-rolling reduction ratios to prepare a number of cold-rolled samples, performs a tensile test on the cold-rolled samples, records the tensile strength, yield strength and elongation data, generates a tensile strength curve, a yield strength curve and an elongation curve based on the test data, extracts key characteristic values ​​to generate a performance matrix, obtains detailed performance data through the tensile test to ensure the accuracy of the results, determines three alternative thicknesses through calculation of the proximity between the performance matrix and the preset performance matrix, customizes three cold-rolled samples based on the alternative thicknesses, and performs a barrier test on the cold-rolled samples. Based on the test results of the barrier test, the optimal thickness of the aluminum foil is determined, and the optimal thickness can be quickly determined, thereby avoiding the situation where the thickness fluctuation of the finished product often leads to insufficient utilization of the aluminum foil material, resulting in waste of resources, or insufficient performance affecting the packaging effect, thereby achieving flexible customization of the aluminum foil;

[0052] (4) The present invention realizes the acceptance of the qualification of the current preparation step by accepting the current hot rolling or cold rolling results, can accurately locate the wrong links in the preparation process, can minimize the losses caused by improper operation, and realize timely inspection and adjustment of the preparation equipment or preparation method, which helps to improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0054] Figure 1 Schematic diagram of the preparation method of the aluminum foil packaging material of the present invention. DETAILED DESCRIPTION

[0055] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0056] In addition, in the present invention, descriptions such as "first" and "second" are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] The present invention provides the following embodiments

[0058] Example 1

[0059] The embodiment of the present invention provides a method for preparing an aluminum foil packaging material and its application, such as Figure 1 As shown, the method includes the following steps:

[0060] S1. preparing a core layer ingot, a barrier layer ingot, and a functional layer ingot, and hot rolling the core layer ingot, the barrier layer ingot, and the functional layer ingot to form a core layer cast plate, a barrier layer cast plate, and a functional layer cast plate, respectively;

[0061] S2. Stacking the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate in sequence, securing them with a fixture, and then placing them into an annealing furnace to combine the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate into one, forming a composite aluminum foil plate; hot rolling the composite aluminum foil plate; and performing a preliminary test to determine an optimal thickness of the aluminum foil after the hot rolling is completed. Based on the test results, a preliminary optimal thickness of the aluminum foil is determined. Cold rolling is performed based on the preliminary optimal thickness of the aluminum foil to finally form a preliminary aluminum foil.

[0062] The preliminary aluminum foil includes a core layer, a barrier layer and a functional layer. The core layer is used to provide basic strength, the barrier layer is used to provide aluminum foil barrier properties, including water vapor barrier properties and oxygen barrier properties, and the functional layer is used to provide antibacterial, light barrier and water vapor barrier functions;

[0063] S3, using a plasma treatment device to perform surface modification on the preliminary aluminum foil, and spraying a layer of antibacterial coating on the surface of the surface-modified preliminary aluminum foil;

[0064] S4. Annealing the preliminary aluminum foil sprayed with the antibacterial coating to form finished aluminum foil. Sampling quality inspection is carried out on each batch of finished aluminum foil. After passing the quality inspection, the finished aluminum foil is cut and packaged.

[0065] Preferably, the thicknesses of the core layer cast plate, the barrier layer cast plate and the functional layer cast plate are 10-20 mm, 8-15 mm and 10-18 mm respectively;

[0066] The thickness of hot-rolled composite aluminum foil is 8-10mm.

[0067] The working principle and beneficial effects of the above technical solution are as follows: the present invention forms an ingot by smelting raw materials of different compositions, forms a three-layer cast plate (core layer cast plate, barrier layer cast plate and functional layer cast plate) through cutting, milling, homogenization treatment and hot rolling, stacks the three-layer cast plate and hot rolls it to form a composite aluminum foil plate, then determines the optimal thickness of the preliminary aluminum foil through a preliminary aluminum foil optimal thickness determination test, cold rolls it based on the preliminary optimal thickness of the aluminum foil, and finally forms a preliminary aluminum foil, modifies the surface of the preliminary aluminum foil by using plasma treatment equipment, and sprays an antibacterial coating on it, anneals the preliminary aluminum foil sprayed with the antibacterial coating, ensures quality through sampling quality inspection, and finally cuts and packages it;

[0068] The present invention adopts a three-layer structural design, in which the core layer provides basic strength, the barrier layer provides aluminum foil barrier properties, including water vapor barrier properties and oxygen barrier properties, and the functional layer provides antibacterial, light barrier and water vapor barrier functions, thereby greatly improving the barrier properties of traditional aluminum foil, effectively blocking the penetration of water vapor, oxygen and light, meeting the packaging needs of high-end ingredients such as matsutake mushrooms, and retaining the original nutritional components and flavor characteristics of high-end ingredients. The preliminary optimal thickness of the aluminum foil is determined through a preliminary aluminum foil optimal thickness determination test, avoiding the situation where the thickness fluctuation of the finished product often leads to insufficient utilization of the aluminum foil material, resulting in waste of resources or insufficient performance affecting the packaging effect. The optimal thickness of the aluminum foil can be determined based on actual needs to achieve flexible customization of the aluminum foil, ensuring product performance while maximizing cost savings. The antibacterial coating uses silver nanoparticles to effectively inhibit the growth of microorganisms and extend the service life of the aluminum foil. Each batch of finished aluminum foil is sampled and quality inspected to ensure the factory quality of the product.

[0069] Example 2

[0070] Based on Example 1, step S1 includes the following steps:

[0071] S11, adding the aluminum foil core layer raw material, the barrier layer raw material, and the functional layer raw material into a melting furnace according to the composition ratio for melting, wherein the melting temperatures of the aluminum foil core layer raw material, the barrier layer raw material, and the functional layer raw material are 700-800° C., 700-750° C., and 750-800° C., respectively;

[0072] S12, pouring the melted core layer raw material, barrier layer raw material, and functional layer raw material into a die casting machine and cooling them to form a core layer ingot, a barrier layer ingot, and a functional layer ingot;

[0073] S13, placing the core layer ingot, the barrier layer ingot, and the functional layer ingot on a sawing machine for cutting, and performing milling on the cut surfaces to ensure a smooth surface;

[0074] S14, placing the cut core layer ingot, barrier layer ingot, and functional layer ingot into an annealing furnace for homogenization treatment;

[0075] S15, hot rolling the core layer ingot, barrier layer ingot and functional layer ingot after homogenization treatment to form core layer cast plate, barrier layer cast plate and functional layer cast plate, with the hot rolling temperature being 400-450°C.

[0076] Preferably, the core layer raw material composition ratio is: aluminum 99.3%, iron 0.1%, copper 0.1%, magnesium 0.15%, zirconium 0.05%, silicon 0.1%, titanium 0.1%, graphene oxide 0.05%, carbon nanotubes 0.05%;

[0077] Barrier layer raw material composition ratio: aluminum 99%, iron 0.05%, copper 0.05%, magnesium 0.05%, silicon 0.05%, titanium 0.05%, chromium 0.2%, yttrium 0.1%, tin 0.1%, nano-silicon dioxide 0.3%, graphene 0.05%;

[0078] The proportion of raw materials in the functional layer is as follows: 99.1% aluminum, 0.05% iron, 0.03% copper, 0.02% magnesium, 0.05% silicon, 0.05% titanium, 0.3% polyvinylidene chloride, 0.2% ethylene-vinyl alcohol copolymer, 0.1% silver-zinc composite nanoparticles, and 0.1% titanium dioxide nanotubes.

[0079] The working principle and beneficial effects of the above technical solution are as follows: the present invention ensures the quality of material properties of each layer by precisely controlling the melting temperature and component ratio; the cutting and milling processes ensure surface smoothness, thus avoiding subsequent processing defects; the homogenization process eliminates internal stress and improves the consistency of material properties; the hot rolling temperature is moderate, thus ensuring the plasticity of the material and improving production efficiency;

[0080] The core layer of the present invention provides basic strength (0.05% graphene oxide and 0.05% carbon nanotubes can enhance the bonding force between the core layer and the barrier layer and improve the mechanical strength of the aluminum foil, 0.15% magnesium and 0.05% zirconium can improve the corrosion resistance and service life of the aluminum foil), the barrier layer enhances barrier performance (0.3% nano-silicon dioxide can reduce water vapor transmission rate, 0.2% chromium and 0.1% yttrium can increase oxygen barrier properties, and 0.05% graphene can form a hydrophobic surface to reduce water adsorption), and the functional layer adds antibacterial and light-blocking functions (0.1% silver-zinc composite nanoparticles have antibacterial effects, 0.3% polyvinylidene chloride and 0.2% ethylene-vinyl alcohol copolymer have water vapor and oxygen barrier functions, and 0.1% titanium dioxide nanotubes can block ultraviolet rays;

[0081] The present invention uses a three-layer structural design to control the water content of high-end ingredients such as matsutake to below 3%, thereby extending the shelf life of high-end ingredients such as matsutake by more than 5 times and retaining the original nutritional components and flavor characteristics of the high-end ingredients.

[0082] Example 3

[0083] On the basis of Example 1, a preliminary test for determining the optimal thickness of the aluminum foil is performed after the hot rolling is completed. The preliminary optimal thickness of the aluminum foil is determined based on the test results, including:

[0084] S21, cold rolling the hot-rolled composite aluminum foil sheet according to different cold rolling reduction ratios to prepare a plurality of cold-rolled samples, measuring the thickness of each cold-rolled sample and recording the thickness value;

[0085] S22. Prepare each cold-rolled sample into a standard specimen according to the standard requirements of the tensile test, perform a tensile test on each cold-rolled sample using a universal material testing machine, and record the tensile strength, yield strength, and elongation data of the cold-rolled sample during the test;

[0086] S23. Generate a corresponding performance matrix based on the tensile strength, yield strength, and elongation data of the cold-rolled samples during the test; determine three alternative thicknesses based on the performance matrix of each cold-rolled sample and a preset performance matrix; customize three cold-rolled samples based on the alternative thicknesses; conduct a barrier property test on the cold-rolled samples; and determine a preliminary optimal thickness of the aluminum foil based on the test results of the barrier property test.

[0087] The working principle and beneficial effects of the above technical solution are as follows: the present invention cold-rolls the hot-rolled composite aluminum foil sheet according to different cold-rolling reduction ratios to prepare a plurality of cold-rolled samples, and each cold-rolled sample is prepared into a standard specimen according to the standard requirements of the tensile test, that is, the dimensions of each cold-rolled sample except for the thickness are standardized, and the tensile strength, yield strength and elongation data of the cold-rolled samples during the test are recorded, wherein the tensile strength can reflect the material strength of the aluminum foil when used for product packaging, and the yield strength and elongation can reflect the material shape adaptability of the aluminum foil when used for product packaging. The preset performance matrix is ​​a performance-customized matrix based on the required packaging performance of the packaged product;

[0088] The present invention cold-rolls the hot-rolled composite aluminum foil plate according to different cold-rolling reduction rates to prepare a number of cold-rolled samples, performs a tensile test on the cold-rolled samples, records tensile strength, yield strength and elongation data, generates a tensile strength curve, a yield strength curve and an elongation curve based on the test data, extracts key characteristic values ​​to generate a performance matrix, obtains detailed performance data through the tensile test to ensure the accuracy of the results, determines three alternative thicknesses based on the proximity calculation between the performance matrix and a preset performance matrix (a packaging performance matrix designed based on the packaged product), customizes three cold-rolled samples based on the alternative thicknesses, performs a barrier test on the cold-rolled samples, and determines the optimal thickness of the aluminum foil based on the test results of the barrier test. The optimal thickness can be determined quickly, avoids the situation where the thickness fluctuation of the finished product often leads to insufficient utilization of the aluminum foil material, resulting in waste of resources, or insufficient performance affecting the packaging effect, thereby realizing flexible customization of the aluminum foil.

[0089] Example 4

[0090] Based on Example 3, step S23 includes:

[0091] S231. Generate a tensile strength curve, a yield strength curve, and an elongation curve based on the tensile strength, yield strength, and elongation data of the cold-rolled sample during the test;

[0092] S232, extracting key eigenvalues ​​of the tensile strength curve, the yield strength curve, and the elongation curve; generating a tensile strength eigenvector, a yield strength eigenvector, and an elongation eigenvector based on the key eigenvalues ​​of the tensile strength curve, the yield strength curve, and the elongation curve; and generating a performance matrix corresponding to the cold-rolled sample based on the tensile strength eigenvector, the yield strength eigenvector, and the elongation eigenvector;

[0093] S233. Calculate the proximity between the performance matrix of the cold-rolled sample and the preset performance matrix, select the thicknesses corresponding to the top three cold-rolled samples ranked by proximity between the performance matrix of the cold-rolled sample and the preset performance matrix as candidate thicknesses, customize three cold-rolled samples based on the candidate thicknesses, perform barrier property tests on the cold-rolled samples, and select the candidate thickness corresponding to the cold-rolled sample with the best barrier property as the preliminary optimal thickness of the aluminum foil;

[0094] Calculate the closeness between the performance matrix of the cold-rolled sample and the preset performance matrix:

[0095] in, is the closeness between the performance matrix corresponding to the kth cold-rolled sample and the preset performance matrix, x kij is the value of the i-th row and j-th column in the performance matrix corresponding to the k-th cold-rolled sample, x 0ij is the value of the i-th row and j-th column in the preset performance matrix, a is the total number of rows in the performance matrix, and b is the total number of columns in the performance matrix.

[0096] The working principle and beneficial effects of the above technical solution are as follows: The present invention generates a tensile strength curve, a yield strength curve, and an elongation curve based on test data, extracts key characteristic values ​​of the curves (including the maximum value, average value, and inflection point position of the tensile strength curve, yield strength curve, and elongation curve) to generate a characteristic vector, and generates a performance matrix based on the characteristic vector. By calculating the proximity between the cold-rolled sample performance matrix and a preset performance matrix, the thicknesses corresponding to the top three cold-rolled samples are selected as candidate thicknesses. Three cold-rolled samples are customized based on the candidate thicknesses, and barrier properties tests are performed on the cold-rolled samples. The candidate thickness corresponding to the cold-rolled sample with the best barrier properties is selected as the preliminary optimal thickness of the aluminum foil. The barrier properties here are mainly determined based on water vapor barrier properties, so that the aluminum foil can be precisely customized based on the actual usage requirements of the specific packaged products.

[0097] The present invention takes into account each element in the matrix when calculating the proximity between the performance matrix corresponding to the cold-rolled sample and the preset performance matrix, thereby ensuring the accuracy of the calculation result.

[0098] Example 5

[0099] Based on Example 1, step S3 includes:

[0100] S31, placing the preliminary aluminum foil into a plasma treatment device, setting the gas type to argon or nitrogen, and the treatment time to 30 seconds to 1 minute to increase the surface activity;

[0101] S32. Use a spraying device to evenly spray the antibacterial coating on the surface of the preliminary aluminum foil, and control the coating thickness to be 0.001-0.002 mm, wherein the antibacterial coating uses silver nanoparticles.

[0102] The working principle and beneficial effects of the above technical solution are as follows: the plasma treatment of the present invention improves surface activity and enhances coating adhesion, the silver nanoparticles have high antibacterial ability, and the spraying equipment can ensure uniform distribution of the coating, thereby improving the packaging performance of the aluminum foil.

[0103] Example 6

[0104] Based on Example 1, during the preparation of each batch of aluminum foil packaging materials, a sampling thickness test is required at the completion of each hot rolling or cold rolling step to inspect and accept the current hot rolling or cold rolling results. The steps are as follows:

[0105] Step 1: Select m hot-rolled or cold-rolled products from the current hot-rolled or cold-rolled products for thickness testing. The thickness testing step is to evenly divide each hot-rolled or cold-rolled product into j testing segments along the length direction, take the midpoint of each testing segment for thickness testing, and obtain the thickness value at the midpoint of each testing segment;

[0106] Step 2: Based on the thickness values ​​at the midpoint of each detection section of the m hot-rolled or cold-rolled products, calculate the thickness qualification assessment value of the current hot-rolled or cold-rolled product:

[0107] Where W is the thickness qualification evaluation value of the product after the current hot rolling or cold rolling, m is the total number of thickness test samples in the product after the current hot rolling or cold rolling, ξ1 is the influence coefficient of thickness accuracy on thickness qualification, n is the number of test sections of the product after the hot rolling or cold rolling, H ij is the thickness value at the midpoint of the jth detection section of the i-th sampled product after hot rolling or cold rolling, H0 is the preset thickness value of the current hot rolling or cold rolling product, and ξ2 is the influence coefficient of thickness uniformity on thickness acceptance;

[0108] If the thickness qualification assessment value of the product after the current hot rolling or cold rolling is greater than the benchmark thickness qualification assessment value, it proves that the current preparation step has passed the acceptance. Otherwise, it proves that the current preparation step has failed the acceptance, and an alarm is issued, and the preparation equipment or preparation method is checked and adjusted in time.

[0109] The working principle and beneficial effects of the above technical solution are as follows: the present invention extracts m hot-rolled or cold-rolled products from the current hot-rolled or cold-rolled products for thickness detection. The thickness detection step is to evenly divide each hot-rolled or cold-rolled product into j detection segments along the length direction, take the midpoint of each detection segment for thickness detection, and obtain the thickness value at the midpoint of each detection segment. The extraction of multiple samples and the measurement of all detection segments ensure the accuracy of the calculation results. At the same time, when calculating the thickness qualification evaluation value of the current hot-rolled or cold-rolled product, not only the accuracy of the thickness of the current hot-rolled or cold-rolled product is taken into consideration. Also takes into account the uniformity of the product thickness after the current hot rolling or cold rolling Thus, the acceptance of the current preparation steps can be achieved from multiple aspects;

[0110] The present invention realizes the acceptance of the qualification of the current preparation step by accepting the current hot rolling or cold rolling results. Acceptance after each hot rolling or cold rolling can accurately locate the wrong links in the preparation process, minimize the production losses caused by improper operation, and realize timely inspection and adjustment of the preparation equipment or preparation method, which helps to improve product quality and ensure the stability of production quality.

[0111] Example 7

[0112] Based on Example 1, step S4 performs quality inspection on the finished aluminum foil, including appearance evaluation, performance evaluation and dimensional conformity evaluation;

[0113] The appearance evaluation includes using image acquisition equipment and a trained aluminum foil surface smoothness evaluation model to perform sampling surface smoothness evaluation on each batch of finished aluminum foil to obtain the surface smoothness evaluation value of each batch of finished aluminum foil;

[0114] The performance evaluation includes sampling and testing the antimicrobial performance, barrier performance and mechanical performance of each batch of finished aluminum foil to obtain the antimicrobial performance evaluation value, barrier performance evaluation value and mechanical performance evaluation value of each batch of finished aluminum foil;

[0115] The dimensional conformity assessment includes sampling thickness testing of each batch of finished aluminum foil and calculating the dimensional conformity assessment value of the current batch of finished aluminum foil based on the thickness test results;

[0116] Based on the surface smoothness evaluation value, antimicrobial performance evaluation value, barrier performance evaluation value, mechanical performance evaluation value, and dimensional conformity evaluation value of each batch of finished aluminum foil, a comprehensive performance evaluation value of each batch of finished aluminum foil is obtained, and quality inspection results are generated based on the comprehensive performance evaluation value of each batch of finished aluminum foil;

[0117] Among them, the comprehensive performance evaluation value of each batch of finished aluminum foil is:

[0118] Among them, ∈ is the comprehensive performance evaluation value of the current batch of finished aluminum foil, Z αβ is the αth evaluation value corresponding to the βth sample in the current batch of finished aluminum foil, γ α is the weight of the αth evaluation value, and y is the total number of samples of the current batch of finished aluminum foil.

[0119] Preferably, antibacterial performance quality inspection test:

[0120] Cut five 100mm×100mm specimens from the finished aluminum foil, clean them with ethanol, and sterilize them with ultraviolet light for 30 minutes;

[0121] The bacterial suspension (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538) was diluted with 0.85% NaCl solution to a concentration of 1 × 10 6CFU / mL;

[0122] 20 μL of bacterial suspension was dripped onto the surface of the sample and covered with a polyethylene film (40 mm × 40 mm) to prevent evaporation. Sterile aluminum foil was used in the control group, and the experimental group was the aluminum foil of the present invention. After incubation at 37°C for 24 hours, the number of colonies in the experimental and control groups was counted, and the antibacterial performance evaluation value was calculated. The antibacterial performance evaluation values ​​of the five samples were used as the antibacterial performance evaluation values ​​of the current batch of finished aluminum foil.

[0123] Preferably, the barrier performance quality inspection test includes an oxygen barrier performance test and a water vapor barrier performance test:

[0124] Oxygen barrier performance test:

[0125] Cut three circular specimens with a diameter of 100 mm and clamp them between two cups at 23°C. The gap between the two cups is sealed. One cup is filled with oxygen and the other with nitrogen to ensure that the air pressure on the left and right sides of the circular specimen is balanced. The oxygen transmission rate within the preset time is recorded and the oxygen barrier performance evaluation value is calculated based on the oxygen transmission rate. The average of the oxygen barrier performance evaluation values ​​of the three circular specimens is used as the oxygen barrier performance evaluation value of the current batch of finished aluminum foil.

[0126] For the water vapor barrier performance test, the oxygen and nitrogen in the above test were replaced with water vapor and nitrogen.

[0127] Preferably, mechanical properties quality inspection test:

[0128] Take several samples for tensile testing, record the tensile strength, yield strength and elongation data, and calculate the mechanical property evaluation value of the current batch of finished aluminum foil based on the tensile strength, yield strength and elongation data.

[0129] The working principle and beneficial effects of the above technical solution are as follows: the present invention uses an image acquisition device and a trained evaluation model to evaluate surface smoothness, conducts sampling antibacterial performance, barrier performance and mechanical performance quality inspection tests on each batch of finished aluminum foil, evaluates the antibacterial performance, barrier performance and mechanical performance of each batch of finished aluminum foil, evaluates the dimensional conformity of the current batch of finished aluminum foil by sampling thickness detection, and finally obtains a comprehensive performance evaluation value for each batch of finished aluminum foil based on the surface smoothness evaluation value, antibacterial performance evaluation value, barrier performance evaluation value, mechanical performance evaluation value and dimensional conformity evaluation value of each batch of finished aluminum foil. When the comprehensive performance evaluation value of each batch of finished aluminum foil is greater than a preset comprehensive performance evaluation value, it is proved that the current product is qualified; otherwise, it is unqualified.

[0130] Among them, the α evaluation values ​​corresponding to the βth sample in the current batch of finished aluminum foil include the surface smoothness evaluation value, the antibacterial performance evaluation value, the barrier performance evaluation value, the mechanical performance evaluation value and the dimensional conformity evaluation value.

[0131] Example 8

[0132] Based on any one of Examples 1-7, an aluminum foil packaging material is used, which is prepared using the aluminum foil packaging material preparation method as in any one of Examples 1-7 and is used for packaging freeze-dried products. The freeze-dried products are not easily damp in the aluminum foil material, and the freeze-dried products are freeze-dried matsutake mushrooms.

[0133] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for preparing an aluminum foil packaging material, characterized in that: The following steps are involved: S1. preparing a core layer ingot, a barrier layer ingot, and a functional layer ingot, and hot rolling the core layer ingot, the barrier layer ingot, and the functional layer ingot to form a core layer cast plate, a barrier layer cast plate, and a functional layer cast plate, respectively; S2. Stacking the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate in sequence, securing them with a fixture, and then placing them into an annealing furnace to combine the core layer cast plate, the barrier layer cast plate, and the functional layer cast plate into one, forming a composite aluminum foil plate; hot rolling the composite aluminum foil plate; and performing a preliminary test to determine an optimal thickness of the aluminum foil after the hot rolling is completed. Based on the test results, a preliminary optimal thickness of the aluminum foil is determined. Cold rolling is performed based on the preliminary optimal thickness of the aluminum foil to finally form a preliminary aluminum foil. The preliminary aluminum foil includes a core layer, a barrier layer and a functional layer. The core layer is used to provide basic strength, the barrier layer is used to provide aluminum foil barrier properties, including water vapor barrier properties and oxygen barrier properties, and the functional layer is used to provide antibacterial, light barrier and water vapor barrier functions; S3, using a plasma treatment device to perform surface modification on the preliminary aluminum foil, and spraying a layer of antibacterial coating on the surface of the surface-modified preliminary aluminum foil; S4. Annealing the preliminary aluminum foil sprayed with the antibacterial coating to form a finished aluminum foil, sampling and quality inspection each batch of the finished aluminum foil, and slitting and packaging the finished aluminum foil after passing the quality inspection; wherein the composition weight percentage of the core layer raw material is as follows: aluminum 99.3%, iron 0.1%, copper 0.1%, magnesium 0.15%, zirconium 0.05%, silicon 0.1%, titanium 0.1%, graphene oxide 0.05%, and carbon nanotubes 0.05%; The composition of the barrier layer raw materials by mass percentage is: aluminum 99%, iron 0.05%, copper 0.05%, magnesium 0.05%, silicon 0.05%, titanium 0.05%, chromium 0.2%, yttrium 0.1%, tin 0.1%, nano-silicon dioxide 0.3%, and graphene 0.05%; The components of the functional layer raw materials are as follows by mass percentage: aluminum 99.1%, iron 0.05%, copper 0.03%, magnesium 0.02%, silicon 0.05%, titanium 0.05%, polyvinylidene chloride 0.3%, ethylene-vinyl alcohol copolymer 0.2%, silver-zinc composite nanoparticles 0.1%, and titanium dioxide nanotubes 0.1%.

2. The method for preparing an aluminum foil packaging material according to claim 1, wherein: Step S1 includes the following steps: S11, adding the aluminum foil core layer raw material, the barrier layer raw material, and the functional layer raw material into a melting furnace according to the composition ratio for melting, wherein the melting temperatures of the aluminum foil core layer raw material, the barrier layer raw material, and the functional layer raw material are 700-800° C., 700-750° C., and 750-800° C., respectively; S12, pouring the melted core layer raw material, barrier layer raw material, and functional layer raw material into a die casting machine and cooling them to form a core layer ingot, a barrier layer ingot, and a functional layer ingot; S13, placing the core layer ingot, the barrier layer ingot, and the functional layer ingot on a sawing machine for cutting, and performing milling on the cut surfaces to ensure a smooth surface; S14, placing the cut core layer ingot, barrier layer ingot, and functional layer ingot into an annealing furnace for homogenization treatment; S15, hot rolling the core layer ingot, barrier layer ingot and functional layer ingot after homogenization treatment to form core layer cast plate, barrier layer cast plate and functional layer cast plate, with the hot rolling temperature being 400-450° C.; The thicknesses of the core layer cast plate, barrier layer cast plate and functional layer cast plate are 10-20 mm, 8-15 mm and 10-18 mm respectively; The thickness of hot-rolled composite aluminum foil is 8-10mm.

3. The method for preparing an aluminum foil packaging material according to claim 1, wherein: After hot rolling, a preliminary test is conducted to determine the optimal thickness of the aluminum foil. The optimal thickness of the aluminum foil is determined based on the test results, including: S21, cold rolling the hot-rolled composite aluminum foil sheet according to different cold rolling reduction ratios to prepare a plurality of cold-rolled samples, measuring the thickness of each cold-rolled sample and recording the thickness value; S22. Prepare each cold-rolled sample into a standard specimen according to the standard requirements of the tensile test, perform a tensile test on each cold-rolled sample using a universal material testing machine, and record the tensile strength, yield strength, and elongation data of the cold-rolled sample during the test; S23. Generate a corresponding performance matrix based on the tensile strength, yield strength, and elongation data of the cold-rolled samples during the test; determine three alternative thicknesses based on the performance matrix of each cold-rolled sample and a preset performance matrix; customize three cold-rolled samples based on the alternative thicknesses; conduct a barrier property test on the cold-rolled samples; and determine a preliminary optimal thickness of the aluminum foil based on the test results of the barrier property test.

4. The method for preparing an aluminum foil packaging material according to claim 3, wherein: Step S23 includes: S231. Generate a tensile strength curve, a yield strength curve, and an elongation curve based on the tensile strength, yield strength, and elongation data of the cold-rolled sample during the test; S232, extracting key eigenvalues ​​of the tensile strength curve, the yield strength curve, and the elongation curve; generating a tensile strength eigenvector, a yield strength eigenvector, and an elongation eigenvector based on the key eigenvalues ​​of the tensile strength curve, the yield strength curve, and the elongation curve; and generating a performance matrix corresponding to the cold-rolled sample based on the tensile strength eigenvector, the yield strength eigenvector, and the elongation eigenvector; S233. Calculate the proximity between the performance matrix of the cold-rolled sample and the preset performance matrix, use the thicknesses corresponding to the top three cold-rolled samples ranked by proximity between the performance matrix of the cold-rolled sample and the preset performance matrix as alternative thicknesses, customize three cold-rolled samples based on the alternative thicknesses, conduct a barrier property test on the cold-rolled samples, and select the alternative thickness corresponding to the cold-rolled sample with the best barrier property as the preliminary optimal thickness of the aluminum foil.

5. The method for preparing an aluminum foil packaging material according to claim 4, characterized in that: Calculate the closeness between the performance matrix of the cold-rolled sample and the preset performance matrix: ;in, is the closeness between the performance matrix corresponding to the kth cold-rolled sample and the preset performance matrix, is the value of the i-th row and j-th column in the performance matrix corresponding to the k-th cold-rolled sample, is the value of the i-th row and j-th column in the preset performance matrix, a is the total number of rows in the performance matrix, and b is the total number of columns in the performance matrix.

6. The method for preparing an aluminum foil packaging material according to claim 1, wherein: Step S3 includes: S31, placing the preliminary aluminum foil into a plasma treatment device, setting the gas type to argon or nitrogen, and the treatment time to 30 seconds to 1 minute to increase the surface activity; S32. Use a spraying device to evenly spray the antibacterial coating on the surface of the preliminary aluminum foil, and control the coating thickness to be 0.001-0.002 mm, wherein the antibacterial coating uses silver nanoparticles.

7. The method for preparing an aluminum foil packaging material according to claim 1, wherein: Step S4: performing quality inspection on the finished aluminum foil, including appearance evaluation, performance evaluation and dimensional conformity evaluation; The appearance evaluation includes using image acquisition equipment and a trained aluminum foil surface smoothness evaluation model to perform sampling surface smoothness evaluation on each batch of finished aluminum foil to obtain the surface smoothness evaluation value of each batch of finished aluminum foil; The performance evaluation includes sampling and testing the antimicrobial performance, barrier performance and mechanical performance of each batch of finished aluminum foil to obtain the antimicrobial performance evaluation value, barrier performance evaluation value and mechanical performance evaluation value of each batch of finished aluminum foil; The dimensional conformity assessment includes sampling thickness testing of each batch of finished aluminum foil and calculating the dimensional conformity assessment value of the current batch of finished aluminum foil based on the thickness test results; Based on the surface smoothness evaluation value, antimicrobial performance evaluation value, barrier performance evaluation value, mechanical performance evaluation value, and dimensional conformity evaluation value of each batch of finished aluminum foil, a comprehensive performance evaluation value of each batch of finished aluminum foil is obtained, and quality inspection results are generated based on the comprehensive performance evaluation value of each batch of finished aluminum foil; Among them, the comprehensive performance evaluation value of each batch of finished aluminum foil is: ;in, is the comprehensive performance evaluation value of the current batch of finished aluminum foil, This is the first batch of finished aluminum foil The corresponding sample An evaluation value, For the The weight of the evaluation value, It is the total number of samples of the current batch of finished aluminum foil.

8. An application of an aluminum foil packaging material, prepared by the method for preparing an aluminum foil packaging material according to any one of claims 1 to 7, characterized in that: The prepared aluminum foil packaging material is used for packaging freeze-dried products.

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