A composite film, a packaging material comprising the composite film, a packaging method thereof, and its application.

Abstract

The application provides a composite film, a packaging material containing the composite film, a packaging method and application thereof, and the composite film comprises a heat-seal anti-adhesion layer; the heat-seal anti-adhesion layer comprises an anti-adhesion material, an inorganic filler A, a polyolefin A and an ultra-high molecular weight polyethylene; and the anti-adhesion material comprises an organic silicon compound. The composite film effectively improves the anti-adhesion performance of the inner layer of the composite film to candies or other foods by designing a heat-seal anti-adhesion layer. The composite film has good tearing performance when used for packaging candies or other foods, and the candies or other foods remain intact without obvious damage after being torn open.

Description

Technical Field

[0001] This invention belongs to the field of food science and technology, and specifically relates to a composite film, packaging materials containing the composite film, packaging methods, and applications. Background Technology

[0002] Food packaging composite film refers to a thin film made of two or more different material layers compounded by a certain process. It is used to package food and play a role in protecting, preserving freshness and extending the shelf life of food.

[0003] Currently, the commonly used composite film materials for food packaging are studied using the following methods: 1. Single-layer structure: Packaging film composed of one material, such as polyethylene (PE), polypropylene (PP), polyester (PET), etc. Single-layer structures are simple and easy to prepare, but have poor oxygen and moisture permeability, making them unsuitable for long-term storage and foods with high preservation requirements. 2. Double-layer structure: Packaging film composed of two different material layers, one of which has certain oxygen and moisture permeability, which can be used to increase the preservation performance of the packaging film. Common double-layer structures include polyethylene / polyester (PE / PET), polyethylene / polypropylene (PE / PP), etc. 3. Triple-layer structure: Packaging film composed of three different materials, one of which has good oxygen and moisture permeability to increase the preservation performance of the packaging film, and another layer is a barrier layer to prevent the penetration of moisture, oxygen, and other harmful substances. Common triple-layer structures include polyethylene / nylon / polyester (PE / NV / PET), polyethylene / polyvinyl alcohol / polyethylene (PE / EVOH / PE), etc.

[0004] For candy packaging, most currently use composite film packaging similar to other foods. However, firstly, candy is highly sticky, especially oil-in-water gel candies, which can stick severely to the inner layer of the composite film. Currently, commercially available products mainly use edible oils pre-coated onto the composite film to prevent sticking. This method increases the product's greasiness, leaving a negative impression on consumers and reducing their willingness to consume it. Furthermore, the coated oil can easily contaminate the heat-sealed area of ​​the composite film during packaging, causing leaks and leading to spoilage within the candy's shelf life. Secondly, during long-term storage, the adhesive pre-coated aluminum foil can gradually migrate into acidic foods. The total migration amount of simulated acidic food liquid from the aluminum foil far exceeds national standards, posing a food safety risk. Thirdly, due to the packaging of oily candies, the peel strength and oil resistance of the adhesive and heat-sealing layer also need to be addressed. Summary of the Invention

[0005] To address the problems and shortcomings of existing technologies, this invention provides a composite film, packaging materials containing the composite film, packaging methods, and their applications in packaging. This composite film, by incorporating a heat-sealing anti-stick layer, effectively improves the anti-stick performance of the inner layer for candies or other foods. Furthermore, packaging candies or other foods with this composite film exhibits excellent tear resistance; after being torn open, the candies or other foods remain intact without significant damage.

[0006] According to a first aspect of the present invention, a composite film is provided, comprising a heat-sealable anti-stick layer; the heat-sealable anti-stick layer comprises an anti-stick material, an inorganic filler A, a polyolefin A, and ultra-high molecular weight polyethylene; the anti-stick material comprises an organosilicon compound.

[0007] The composite film provided by this invention contains an anti-sticking layer made of organosilicon compounds such as siloxane polymers or siloxanes, and also contains micron-sized inorganic filler A. Firstly, the inorganic filler provides micron-sized bumps and depressions, while the organosilicon polymers, being incompatible with polyolefins such as PE, form nano-sized bumps and depressions on the surface, thus creating a micro-nano sized uneven film surface. Secondly, the presence of siloxane organic compounds within the organic material significantly reduces the surface tension, thereby achieving an anti-sticking effect. Furthermore, micron-sized ultra-high molecular weight polyethylene (UHMWPE) is introduced into the heat-sealing anti-sticking layer. UHMWPE does not melt during the film preparation process and has high thermal stability. Therefore, UHMWPE particles can compensate for the depressions in the micron-sized material during blown film preparation (UHMWPE particles float on the film surface), further improving the protruding structure of the film surface and reducing the surface tension of the film.

[0008] The combined effect of these factors results in numerous microscopic protrusions on the surface of the inner layer of the composite layer (heat-sealing anti-stick layer), mainly caused by large particles floating on the surface. This effectively reduces the surface tension of the inner layer of the composite layer (heat-sealing anti-stick layer), thereby effectively reducing the contact angle between the candy or other food and the inner layer of the composite film. This gives the inner layer of the composite film good anti-stick properties for candy, especially water-in-oil gel candy, and effectively maintains the integrity of the candy or other food after the packaging is opened.

[0009] Meanwhile, the composite film prepared using the above-mentioned heat-sealing anti-stick layer has suitable tear resistance, that is, it has suitable burst resistance. It should not be too high or too low. If it is too high, it will not be easy to puncture or tear, while if it is too low, it will be easy to break during packaging or other transportation processes, which is not conducive to processing, nor to the protection and preservation of candy.

[0010] Preferably, the melting point of the polyolefin A is not lower than 105°C; the melting point of the ultra-high molecular weight polyethylene is not lower than 130°C, and the melt index is not higher than 0.05. Considering that hot filling is often used when packaging candies or other foods, the above-mentioned polyolefin and ultra-high molecular weight polyethylene, i.e., heat-resistant polyolefin (because the filling temperature of such candies is relatively high, the heat resistance requirements of polyethylene need to be considered. Taking polyethylene as an example, 105°C is a watershed. Those with a melting point below 105°C are non-heat-resistant and usually contain substances such as metallocene to lower the melting point, while those above 105°C are heat-resistant), ensure that the material does not soften during the filling process, thereby preventing surface energy and surface micro-failure.

[0011] Preferably, the mass ratio of the anti-sticking material, inorganic filler A, polyolefin A, and ultra-high molecular weight polyethylene is 2~30:1~10:50~80:1~10. Controlling the mass ratio of the various raw materials in the heat-sealing anti-stick layer within a certain range is beneficial for better synergistic effects among the raw materials, resulting in a heat-sealing anti-stick layer with lower surface tension, higher thermal stability, and a longer-lasting characteristic of maintaining its surface structure, thus optimizing long-term anti-sticking performance. Simultaneously, this also helps to achieve more suitable burst resistance in the final heat-sealing anti-stick layer, further enhancing the overall performance of the composite film.

[0012] Preferably, the organosilicon compound includes a siloxane polymer.

[0013] Preferably, in the heat-sealing anti-stick layer, the anti-stick material, such as a siloxane polymer, has a melting point of 80~150℃ and a density of 0.9~1.1g / cm³.

[0014] Preferably, in the heat-sealing anti-stick layer, the D50 of inorganic filler A is 1~10μm; inorganic filler A includes silica. Inorganic filler A within the aforementioned particle size range ensures sufficient micro / nano particle protrusions on the surface of the inner layer of the composite layer (heat-sealing anti-stick layer) to reduce its surface energy, thereby improving the anti-sticking performance of the inner layer (heat-sealing anti-stick layer) surface against candies, especially oil-in-water gel candies. Simultaneously, this particle size distribution facilitates thorough and uniform dispersion in the polymer, further enhancing the performance of inorganic filler A within the film layer.

[0015] Preferably, in the heat-sealing anti-stick layer, the D50 of ultra-high molecular weight polyethylene is 1~40μm. Similarly, this particle size range helps to ensure that the surface of the inner layer of the composite layer (heat-sealing anti-stick layer) has sufficient micro-nano particle protrusions to reduce its surface energy, while also playing a good matching role with inorganic filler A, and further optimizing the anti-stick performance of the film.

[0016] Preferably, the ultra-high molecular weight polyethylene has a melting point of 130~160℃ and a density of 0.93~0.97g / cm³.

[0017] Preferably, the ultra-high molecular weight polyethylene (UHMWPE) is spherical or microspherical. After the film is formed, UHMWPE retains its original spherical or microspherical shape, which is more conducive to its good compatibility with inorganic filler A and further optimizes the anti-sticking properties and other properties of the film.

[0018] Preferably, in the heat-sealing anti-stick layer, polyolefin A independently includes at least one of polyethylene and polypropylene. Polyethylene and polypropylene, as the main polymer materials for packaging composite films, possess high transparency, good mechanical properties, heat resistance and low-temperature resistance, as well as a wide range of applications and environmental friendliness, meeting various usage requirements.

[0019] Preferably, in the heat-sealable anti-stick layer, when the polyolefin A includes polyethylene, and the polyethylene includes low-density polyethylene and metallocene polyethylene, the mass ratio of low-density polyethylene to metallocene polyethylene is 20~60:20~60; or, the polyethylene includes low-density polyethylene and linear low-density polyethylene A, and the mass ratio of low-density polyethylene to linear low-density polyethylene A is 20~60:20~60; when the polyolefin A includes polypropylene, and the polypropylene includes homopolymer polypropylene, binary material, and ternary material, the mass ratio of homopolymer polypropylene, binary material, and ternary material is 10~30:20~30:40~60; the binary material includes a polyolefin material formed by copolymerization of two monomers; the ternary material includes a polyolefin material formed by copolymerization of three monomers. Using the above-mentioned polyolefins to prepare the heat-sealable anti-stick layer is beneficial to make the heat-sealable anti-stick layer uniform and dense, with good processing performance and mechanical properties. At the same time, it is beneficial to form a better micro-nano structure on the surface, so that its low surface energy can be maintained stably for a long time, that is, to provide a long-lasting anti-stick effect and improve its preservation ability for foods such as candy.

[0020] Preferably, the ternary material includes block polypropylene and rubber components.

[0021] Preferably, in the heat-sealable anti-stick layer, the polyolefin A includes polyethylene, and the polyethylene includes low-density polyethylene and metallocene polyethylene. The low-density polyethylene has a melting point of 65~125℃, a melt index of 1~20, and a density of 0.91~0.94 g / cm³; the metallocene polyethylene has a melting point of 80~130℃, a melt index of 1~10, and a density of 0.88~0.93 g / cm³; or, the polyethylene includes low-density polyethylene and linear low-density polyethylene A, where the low-density polyethylene has a melting point of 65~125℃, a melt index of 1~20, and a density of 0.91~0.94 g / cm³. Polyethylene A has a melting point of 80~125℃, a melt index of 1~20, and a density of 0.88~0.93g / cm³. When polyolefin A includes polypropylene, polypropylene includes homopolymer polypropylene, binary polypropylene, and ternary polypropylene; homopolymer polypropylene has a melting point of 150~170℃, a melt index of 1~10, and a density of 0.88~0.92g / cm³; binary polypropylene has a melting point of 135~150℃, a melt index of 1~10, and a density of 0.88~0.92g / cm³; ternary polypropylene has a melting point of 135~170℃, a melt index of 1~10, and a density of 0.88~0.92g / cm³.

[0022] Preferably, the composite film further includes an intermediate barrier layer; the intermediate barrier layer comprises inorganic filler B and polyolefin B, with a mass ratio of inorganic filler B to polyolefin B of 10~80:20~90. The intermediate barrier layer, through the addition of micron-sized inorganic filler B and polyolefin B, exhibits partial protrusion during the blown film process, further influencing the appearance of the heat-sealing anti-stick layer and resulting in a more pronounced protruding micro / nano structure on the surface of the heat-sealing anti-stick layer. Under the aforementioned mass ratio of raw materials, a certain amount of inorganic particle B protrusion is ensured during the blown film process, while simultaneously maintaining the relevant performance of the intermediate barrier layer. This allows for a better bond between the intermediate barrier layer and the heat-sealing anti-stick layer, effectively guaranteeing the overall performance of the composite film.

[0023] Preferably, in the intermediate barrier layer, the inorganic filler B includes at least one of calcium carbonate, talc, mica, and silica; the particle size of the inorganic filler B is not less than 1250 mesh; and the polyolefin B independently includes at least one of polyethylene and polypropylene. The particle size of the inorganic filler B is within the above range, ensuring that the protruding structures during the blown film process have appropriate protrusions, effectively enhancing the appearance of the heat-sealing anti-stick layer without affecting the composite effect of the intermediate barrier layer and the heat-sealing anti-stick layer. Polyethylene and polypropylene, as the main polymer materials for packaging composite films, possess high transparency, good mechanical properties, heat resistance, low-temperature resistance, wide application areas, and environmental friendliness, meeting various usage requirements.

[0024] Preferably, the particle size of inorganic filler B is 2000~10000 mesh.

[0025] Preferably, the intermediate barrier layer further includes a first compatibilizer and a lubricant; the mass ratio of inorganic filler B, polyolefin B, the first compatibilizer, and the lubricant is 10~80:20~90:1~30:0~5; the first compatibilizer includes at least one of maleic anhydride-modified polyolefin and acrylic acid-modified polyolefin; the lubricant includes at least one of calcium stearate, magnesium stearate, and polyethylene wax. Adding a certain amount of compatibilizer is beneficial for the inorganic filler and polymer material to be fully and uniformly mixed, improving the overall uniformity of the membrane layer. At the same time, due to the processing characteristics of inorganic fillers, adding a certain amount of lubricant helps the inorganic filler and polymer material to be more easily processed into a uniform mixture system, resulting in a membrane layer with better quality.

[0026] Preferably, in the intermediate barrier layer, the polyolefin B has a melting point of 80~160℃, a melt index of 1~100, and a density of 0.88~1.0g / cm³.

[0027] Preferably, in the intermediate barrier layer, the polyolefin B includes low-density polyethylene B-1 and metallocene polyethylene B-1; or, the polyolefin B includes low-density polyethylene B-1 and low-density linear polyethylene resin B-1. Preferably, it includes low-density polyethylene B-1, and the mass ratio of low-density polyethylene B-1 to metallocene polyethylene B-1 is 20~70:20~70; or the mass ratio of low-density polyethylene B-1 to low-density linear polyethylene resin B-1 is 20~70:20~70.

[0028] Preferably, in the intermediate barrier layer, the first compatibilizer has a melting point of 80~160℃, a melt index of 1~100, and a density of 0.88~1.0 g / cm³. It should be noted that the compatibilizer is also known as a bonding polyolefin or adhesive polyolefin.

[0029] Preferably, in maleic anhydride-modified polyolefins, the grafting rate of maleic anhydride is 0.1-5%; in acrylic acid-modified polyolefins, the grafting rate of acrylic acid is 2-10%. The introduction of maleic anhydride or acrylic acid grafted-modified polyolefins can improve the adhesion between layers and prevent delamination. Furthermore, the grafting rate determines the adhesion between layers; if it is too low, the adhesion between layers is poor, but if it is too high, it will affect the melting point, mechanical strength, and processing performance of the polymer material, affecting the internal interaction forces of the material, thereby reducing the overall performance of the material.

[0030] Preferably, the composite film further includes a bonding layer, which comprises polyolefin C and a second compatibilizer, wherein the mass ratio of polyolefin C to the second compatibilizer is 10~90:10~90. The function of the bonding layer is to bond with the aluminum foil through the adhesive. The second compatibilizer (adhesive polyolefin) in the bonding layer can act as a bond between the bonding layer and the intermediate barrier layer, preventing delamination problems during stretching after heat sealing.

[0031] Preferably, in the bonding layer, the polyolefin C independently includes at least one of polyethylene and polypropylene.

[0032] Preferably, in the bonding layer, the polyolefin C has a melting point of 65~125℃, a melt index of 1~40, and a density of 0.88~0.93g / cm³; the adhesive polyethylene has a melting point of 65~125℃, a melt index of 1~100, and a density of 0.88~1.0g / cm³.

[0033] Preferably, in the bonding layer, the polyolefin C includes low-density polyethylene C-1 and low-density linear polyethylene resin C-1. Preferably, the mass ratio of low-density polyethylene C-1 to low-density linear polyethylene resin C-1 is 20~70:20~70.

[0034] By controlling the melting point, melt index, and density of the raw materials for each layer of the composite film in this invention—such as the heat-sealing barrier layer, the intermediate barrier layer, and the bonding layer—within a certain range, the final composite film can achieve a balance of thermal stability, processability, and burst resistance, resulting in superior overall performance. Furthermore, when these layers are used in combination in two or three layers, the resulting composite materials exhibit strong adhesion and good cohesive strength, preventing delamination during heat sealing and stretching processes that could affect the film's usability.

[0035] Preferably, the second compatibilizer includes at least one of maleic anhydride-modified polyolefin and acrylic acid-modified polyolefin.

[0036] Preferably, the second compatibilizer has a melting point of 80~160℃, a melt index of 1~100, and a density of 0.88~1.0 g / cm³. It should be noted that the compatibilizer is also known as a bonding polyolefin or adhesive polyolefin.

[0037] Preferably, the thickness of the composite film is 15~100μm, and the thickness ratio of the bonding layer, the intermediate barrier layer, and the heat-sealing anti-stick layer is 1~3:1~5:1~3. Ensuring that the thickness of each layer is within the above range is beneficial in two ways: firstly, it helps to give the composite film a certain mechanical strength and density, which can effectively preserve the freshness of foods such as candies; secondly, it also allows the prepared composite film to have good tear resistance, so that candies and other foods remain intact after being torn and opened.

[0038] According to a second aspect of the present invention, a method for preparing the above-mentioned composite film is provided, comprising the following steps: S1. Preparing a first masterbatch, a second masterbatch, and a third masterbatch for preparing a bonding layer, an intermediate barrier layer, and a heat-sealing anti-stick layer, respectively, and preparing the first masterbatch, the second masterbatch, and the third masterbatch into a first masterbatch, a second masterbatch, and a third masterbatch, respectively; S2. Simultaneously melting, extruding, and blowing the first masterbatch, the second masterbatch, and the third masterbatch into a composite film by cooling; the first masterbatch forms the bonding layer, the second masterbatch forms the intermediate barrier layer, and the third masterbatch forms the heat-sealing anti-stick layer.

[0039] Preferably, in S2, during the melt extrusion molding of the first masterbatch, the processing temperature of the first extruder is 40~200℃; during the melt extrusion molding of the second masterbatch, the processing temperature of the second extruder is 40~200℃; during the melt extrusion molding of the third masterbatch, the processing temperature of the third extruder is 40~200℃; and the die temperature of the co-extrusion is 180~220℃.

[0040] The melt extrusion temperature of polymer films has a significant impact on the swell effect, material properties, and product quality of the extrudate. First, at low shear rates, the swell ratio of the extrudate is related to the melt temperature; the higher the temperature, the faster the relaxation of oriented molecules, leading to a decrease in the swell ratio as temperature increases. Excessive swell effect may result in inaccurate product dimensions, affecting the final performance of the product. Conversely, insufficient swell effect may indicate insufficient flow and orientation of the polymer melt within the die, similarly impacting product quality and performance. Second, excessively high temperatures may cause resin decomposition, making the film brittle, while excessively low temperatures may lead to poor resin plasticization, affecting the tensile strength and surface gloss of the film. Furthermore, increasing the die temperature can improve material flowability, reduce the formation of defects such as bubbles and shrinkage cavities, and improve the surface finish and dimensional accuracy of the product. Simultaneously, an appropriate die temperature can promote crystallization, improving the crystallinity and heat resistance of the product. However, excessively high temperatures may lead to over-crystallization, making the product brittle. Therefore, controlling the melt extrusion temperatures within the aforementioned ranges during production ensures that the product quality and performance meet the expected standards.

[0041] Regarding the composite film provided by this invention, the bonding layer enables the film to adhere to the aluminum foil via an adhesive; the intermediate barrier layer prevents the adhesive from migrating to the food contact layer and prevents food from migrating to the composite layer; the heat-sealing anti-stick layer enables the material to be heat-sealed and provides the anti-stick properties mentioned in this patent.

[0042] According to a third aspect of the present invention, a packaging material is provided, comprising the above-described composite film and aluminum foil, wherein the composite film and aluminum foil are bonded together by an adhesive.

[0043] According to a fourth aspect of the present invention, a method for packaging gel candies is provided, wherein the gel candies are packaged in blister packs sealed by the aforementioned packaging material.

[0044] According to a fifth aspect of the present invention, an application of the above-described composite film in packaging is provided.

[0045] According to a sixth aspect of the present invention, an application of the above-described composite film in gel candy packaging is provided. Using the composite film provided by the present invention for gel candy packaging can improve the anti-sticking effect of the inner layer of the composite material on the gel candy, effectively maintain the integrity of the gel candy, and improve the preservation effect. In particular, because water-in-oil candies release water and oil, resulting in greater viscosity, the composite film provided by the present invention has a more significant anti-sticking effect when applied to water-in-oil gel candies.

[0046] Preferably, the application of the above-mentioned composite film in gel candy packaging includes the following steps: Step 1, preparing an aluminum-containing composite rigid material preformed blister using a cold forming process; Step 2, pouring gel candy raw materials into the aluminum-containing composite rigid material preformed blister, and then heat-sealing the composite film onto the aluminum-containing composite rigid material preformed blister; wherein, the heat-sealing anti-stick layer of the composite film is used to heat-seal the aluminum-containing composite rigid material preformed blister.

[0047] Preferably, the surface of the bonding layer in the composite film is further subjected to corona treatment; and an aluminum foil is disposed on the bonding layer after corona treatment, and the bonding layer and the aluminum foil are bonded together by an adhesive; the adhesive layer includes polyurethane.

[0048] In summary, the composite film provided by this invention, through the addition of inorganic and organic micron-sized particles to its heat-sealing anti-stick layer or the heat-sealing anti-stick layer and intermediate barrier layer, and the introduction of siloxane compounds into the heat-sealing anti-stick layer, effectively reduces the surface tension of the inner layer of the composite layer (heat-sealing anti-stick layer) through various interactions. This effectively reduces the contact angle between the candy or other food and the inner layer of the composite film, giving the inner layer of the composite film good anti-stick properties for candy, especially water-in-oil gel candy, effectively maintaining the integrity of the candy or other food after opening the packaging. Simultaneously, it also enables the packaging prepared from the subsequent composite film to have better tear resistance, and even after replacing traditional heat-sealing adhesive (which is unsuitable for this type of packaging as its components easily migrate into the contents, causing food safety issues), it still maintains good opening performance. The opening performance is significantly improved, and the candy remains intact after opening without obvious damage. In other words, the composite film provided by this invention simultaneously achieves the effects of easy opening (easy tearing), anti-stick properties, and no glue migration. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the composite membrane in one embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram showing the adhesion between the candy and the inner layer of the blister pack in Comparative Example 4 of the present invention.

[0051] Figure 3 This is a schematic diagram showing the adhesion between the candy and the inner layer of the blister pack in Embodiment 1 of the present invention.

[0052] Figure 4 This is a schematic diagram showing the adhesion between the candy and the inner layer of the blister pack in Embodiment 2 of the present invention.

[0053] Figure 5 This is a schematic diagram illustrating the determination of different degrees of candy adhesion in this invention. Detailed Implementation

[0054] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0055] Example 1

[0056] The composite membrane structure in this embodiment is as follows: Figure 1 As shown, where,

[0057] 1. The raw materials for the bonding layer, intermediate barrier layer, and heat-sealing anti-stick layer are as follows:

[0058] The binder layer raw materials are: 60 kg of low-density polyethylene resin (2426H, produced by Sinopec, melting point 110℃, melt index 1.9, density 0.924 g / cm³), 10 kg of adhesive polyolefin resin (ADMER NF108, produced by Mitsui, Japan, melting point 120℃, melt index 1.6, density 0.92 g / cm³), and 30 kg of linear low-density polyethylene resin (1002AY, produced by ExxonMobil, USA, melting point 121℃, melt index 2, density 0.918 g / cm³). The above raw materials are granulated by water stretching using relevant equipment and then dried. The output is controlled at 200 kg / hour to obtain the first masterbatch.

[0059] Intermediate barrier layer raw materials: 40 kg of low-density polyethylene resin (2426H, produced by Sinopec, melting point 110℃, melt index 1.9, density 0.924 g / cm³), 10 kg of adhesive polyolefin resin (Admer NF528A, produced by Mitsui Chemicals, Japan, melting point 100℃, melt index 4.0, density 0.91 g / cm³), 30 kg of metallocene polyethylene resin (2045.11G, produced by Dow Chemical, USA, melting point 122℃, melt index 1.0, density 0.922 g / cm³), 10 kg of food-grade calcium carbonate (produced by Jiangxi Chuangxian Fine Calcium Industry, 8000 mesh), and 10 kg of talc powder (produced by Liaoning Xinda, model SDC-9272, 2000 mesh); 2426H and Admer... NF528 and 2045.11G were first ground into fine powder under liquid nitrogen conditions, with a particle size of 300 mesh. Then, the moisture content was dried to below 0.5% in an oven. The ground and dried 2426H, Admer NF528, and 2045.11G were then added to a high-speed mixer along with food-grade calcium carbonate and talc. The mixing speed was 2000 rpm, and the temperature was controlled at 60℃. After high-speed mixing for 40 minutes, all materials were drawn into the hopper of a twin-screw extruder through a pipe. The plastic strips coming out of the twin screw were cooled with water (at a temperature of 20℃), then sheared, dried, and granulated at a drying temperature of 80℃ to obtain the second masterbatch.

[0060] In the preparation of the second masterbatch, the twin-screw extruder used was a Nanjing Kailida Machinery Equipment Co., Ltd. TSE-52B co-rotating parallel twin-screw blending extrusion granulator. Specific parameters are shown in Table 1.

[0061] Table 1. Specific extrusion parameters of the twin-screw extruder

[0062]

[0063] Heat-sealing anti-stick layer raw materials: 30 kg of low-density polyethylene resin (2426H, produced by Sinopec, melting point 110℃, melt index 1.9, density 0.924 g / cm³), 45 kg of metallocene polyethylene resin (2045.11G, produced by Dow Chemical, USA, melting point 122℃, melt index 1.0, density 0.922 g / cm³), 20 kg of siloxane polymer (produced by Zhejiang Jiahua Fine Chemicals Co., Ltd., model Javachem PSA-300, melting point 105℃, melt index 300, density 0.96 g / cm³), 3 kg of silica (produced by PQCORPORATION, model HP 230, D50 3.6μm, oil absorption 250g / 100g), and 1 kg of ultra-high molecular weight polyethylene (MIPELON). PM200, manufactured by Mitsui, Japan, with a D50 of 10μm, melting point of 121℃, molecular weight of 2 million, and density of 0.94g / cm³, weighs 2 kg.

[0064] First, 2426H, 2045.11G, and Javachem PSA-300 (siloxane polymer) were each ground into fine powder under liquid nitrogen conditions, with a particle size of 300 mesh. Then, the moisture content was dried to below 0.5% in an oven. Then, Javachem PSA... -300 (siloxane polymer) powder and silica are stirred at high speed (so that the surface hydroxyl groups of siloxane and silica complete part of the polycondensation reaction first, and the silane polymer itself also has some reactive hydroxymethyl groups, which can undergo polycondensation reaction with the surface hydroxyl groups of silica, release methanol, and increase the bonding force between the two substances). The high-speed stirring equipment controls the temperature at 80℃ and the stirring time is 15min. Then, the above-ground 2426H, metallocene 2045.11G and MIPELONPM200 (ultra-high molecular weight polyethylene) are added and the mixture is stirred at high speed for 30min, the speed is 1200 rpm, and the temperature is controlled at 60℃. Then, the mixture is sucked into the twin-screw hopper through the pipe. The plastic strip coming out of the twin screw is cooled by water (temperature at 20℃), then sheared, dried and granulated. The drying temperature is 80℃ to obtain the third masterbatch.

[0065] In the preparation of the third masterbatch, the twin-screw extruder used was a Nanjing Kailida Machinery Equipment Co., Ltd. TSE-52B co-rotating parallel twin-screw blending extrusion granulator. Specific parameters are shown in Table 2.

[0066] Table 2 Specific extrusion parameters of the twin-screw extruder

[0067]

[0068] 2. Film blowing (preparation of composite films)

[0069] The first masterbatch, second masterbatch, and third masterbatch prepared above were respectively added to the extruders of the three hoppers of the blown film compounding machine A, B, and C. The equipment was a Wuhan Xinzhongde SXGM-3*1600. The formula is shown in Table 3.

[0070] Table 3. Relevant formulations and thickness parameters for preparing composite membranes

[0071]

[0072] The raw materials listed in Table 3 are heated to a molten state and pushed into the die head by a screw to form a film preform. Air is injected into the preform through an inflation ring, and the inflated film is rapidly cooled by a cooling ring to fix its size and shape. The cooled film is then wound into a roll by a traction roller and a winding machine, ready for subsequent processing.

[0073] The specific processing temperatures are shown in Table 4:

[0074] Table 4 Processing temperature for preparing composite membranes

[0075]

[0076] Simultaneously, the surface of the composite membrane bonding layer is subjected to corona treatment, with a corona discharge of 4KW and a corona discharge rate of 42 dynes or higher.

[0077] 3. Aluminum foil composite

[0078] On the Bobst DA800 laminating machine, aluminum foil with a thickness of 16 micrometers (supplied by Henan Mingtai, hardness H18, alloy grade 8011) is applied to its surface with polyurethane adhesive, Henkel 2788, with an application solids content of 40% and an application amount of 4.0~4.5 gsm. The oven temperature is 90, 90, and 100℃ (three temperature settings). The adhesive is then laminated with the corona-treated surface of the composite film prepared above at a lamination temperature of 50℃ and a speed of 300 m / min. After curing at room temperature for 12 hours after removal from the machine, it undergoes a curing process at 40℃ for 3 days to obtain the aluminum foil composite film, which is then cut into 250 mm widths.

[0079] 4. Candy packaging

[0080] During packaging, cold-formed aluminum material is pre-formed into blister packs, and pre-mixed candy is poured into the cold-formed aluminum blister packs at high temperature. The aluminum foil composite film prepared in this embodiment is then heat-sealed onto the blister packs at 180~190℃ to complete the packaging process. The packaging equipment is a Shanghai Jiangnan DPP260 blister packaging machine.

[0081] Example 2

[0082] The composite membrane structure in this embodiment is as follows: Figure 1 As shown, where,

[0083] 1. The raw materials for the bonding layer, intermediate barrier layer, and heat-sealing anti-stick layer are as follows:

[0084] The binder layer raw materials are: 50 kg of low-density polyethylene resin (FD0474, produced by Lotrene Cadar, melting point 108℃, melt index 4, density 0.923 g / cm³), 5 kg of adhesive polyethylene resin (SF304, produced by Guangzhou Lushan, melting point 112℃, melt index 1.6, density 0.948 g / cm³), and 45 kg of low-density linear polyethylene resin (2036G, produced by Dow Chemical, USA, melting point 125℃, melt index 2.5, density 0.935 g / cm³). The above raw materials are granulated by water stretching using relevant equipment and then dried. The output is controlled at 250 kg / hour to obtain the first masterbatch.

[0085] Intermediate barrier layer raw materials: 35 kg of low-density polyethylene resin (FD0474, produced by Lotrene, melting point 108℃, melt index 4, density 0.923 g / cm³), 15 kg of adhesive polyolefin resin (ADMER NF468E, produced by Mitsui Chemicals, Japan, melting point 120℃, melt index 4, density 0.92 g / cm³), 35 kg of low-density linear polyethylene resin (2036G, produced by Dow Chemical, USA, melting point 125℃, melt index 2.5, density 0.935 g / cm³), 8 kg of food-grade calcium carbonate (produced by Jiangxi Chuangxian Fine Calcium Industry, 10000 mesh), and 12 kg of talc (produced by IMIFABI, model HTPultra5, 4000 mesh); FD0474 and ADMER... NF468E and 2036G were first ground into fine powder under liquid nitrogen conditions, with a particle size of 300 mesh. Then, the moisture content was dried to below 0.5% in an oven. The ground and dried FD0474, ADMER NF468E, and 2036G were then added to a high-speed mixer along with food-grade calcium carbonate and talc. The mixing speed was 1500 rpm, and the temperature was controlled at 60℃. After high-speed mixing for 40 minutes, all materials were drawn into the hopper of a twin-screw extruder through a pipe. The plastic strips coming out of the twin screw were cooled with water (at a temperature of 20℃), then sheared, dried, and granulated at a drying temperature of 80℃ to obtain the second masterbatch.

[0086] In the preparation of the second masterbatch, the twin-screw extruder used was a Nanjing Kailida Machinery Equipment Co., Ltd. TSE-52B co-rotating parallel twin-screw blending extrusion granulator. Specific parameters are shown in Table 5.

[0087] Table 5 Specific extrusion parameters of the twin-screw extruder

[0088]

[0089] Heat-sealing anti-stick layer raw materials: 35 kg of low-density polyethylene resin (FD0474, produced by Lotrene, melting point 108℃, melt index 4, density 0.923 g / cm³), 45 kg of metallocene polyethylene (8784, produced by ExxonMobil, melting point 121℃, melt index 0.8, density 0.914 g / cm³), 20 kg of siloxane polymer (vinyltrimethoxysilane oligomer, model HP-171, produced by Jiangxi Hongbo New Material Co., Ltd.), 2 kg of silica (produced by Grace, model SYLOBLOC® K 200, D50 2.4μm, oil absorption 250g / 100g), and 2 kg of MIPELON XM221U (ultra-high molecular weight polyethylene, produced by Mitsui, Japan, D50 25μm, melting point 136℃, molecular weight 2 million, density 0.94 g / cm³).

[0090] First, FD0474, 8784, and the siloxane polymer (vinyltrimethoxysilane oligomer) are separately ground into fine powders with a particle size of 300 mesh under liquid nitrogen conditions. Then, the moisture content is dried to below 0.5% in an oven. Next, the ground siloxane polymer and silica are stirred at high speed (this allows the surface hydroxyl groups of the siloxane and silica to undergo partial condensation reaction; the siloxane polymer itself also contains reactive hydroxymethyl groups, which can undergo condensation reaction with the surface hydroxyl groups of silica, releasing methanol and increasing the bonding force between the two substances). The high-speed stirring equipment is maintained at 80℃ for 15 minutes. Then, the ground FD0474, 8784, and MIPELON powders are added. XM221U (ultra-high molecular weight polyethylene) was continuously mixed at high speed for 30 minutes at a speed of 1200 rpm and a temperature of 60°C. The mixture was then drawn into a twin-screw hopper through a pipe. The plastic strips that came out of the twin screws were cooled by water (at a temperature of 20°C), then sheared, dried, and granulated at a drying temperature of 80°C to obtain the third masterbatch.

[0091] In the preparation of the third masterbatch, the twin-screw extruder used was a Nanjing Kailida Machinery Equipment Co., Ltd. TSE-52B co-rotating parallel twin-screw blending extrusion granulator. Specific parameters are shown in Table 6.

[0092] Table 6 Specific extrusion parameters of the twin-screw extruder

[0093]

[0094] 2. Film blowing (preparation of composite films)

[0095] The first masterbatch, second masterbatch, and third masterbatch prepared above were respectively added to the extruders of the three hoppers of the blown film compounding machine A, B, and C. The equipment was a Wuhan Xinzhongde SXGM-3*1600. The formula is shown in Table 7.

[0096] Table 7. Relevant formulations and thickness parameters for preparing composite membranes

[0097]

[0098] The raw materials listed in Table 7 are heated to a molten state and pushed into the die head by a screw to form a film preform. Air is injected into the tube through an inflation ring, and the inflated film is rapidly cooled by a cooling ring to fix its size and shape. The cooled film is then wound into a roll by a traction roller and a winding machine, ready for subsequent processing.

[0099] The specific processing temperatures are shown in Table 8:

[0100] Table 8 Processing temperature for preparing composite membranes

[0101]

[0102] Simultaneously, the surface of the composite membrane bonding layer is subjected to corona treatment, with a corona discharge of 4KW and a corona discharge rate of 42 dynes or higher.

[0103] 3. Aluminum foil composite

[0104] On the Bobst DA800 laminating machine, aluminum foil with a thickness of 20 micrometers (supplied by Henan Wanji, hardness H18) is used. Polyurethane adhesive, Gaomeng 3166, with an application solids content of 40% and an application amount of 3.0~3.5 gsm is applied to its surface. The oven temperature is 90, 90, and 100℃ (three temperature settings). The adhesive is then laminated with the corona-treated surface of the composite film prepared above. The lamination temperature is 50℃ and the speed is 300 m / min. After being removed from the machine, the film is cured at room temperature for 12 hours, and then cured at 40℃ for 3 days to obtain the aluminum foil composite film, which is then cut into 250 mm widths.

[0105] 4. Candy packaging

[0106] During packaging, cold-formed aluminum material is pre-formed into blister packs, and pre-mixed candy is poured into the cold-formed aluminum blister packs at high temperature. The aluminum foil composite film prepared in this embodiment is then heat-sealed onto the blister packs at 180~190℃ to complete the packaging process. The packaging equipment is a Shanghai Jiangnan DPP260 blister packaging machine.

[0107] Example 3

[0108] The difference between this embodiment and Embodiment 1 is that the heat-sealing anti-stick layer uses the same proportion of silica microspheres with a D50 of 15μm produced by Fucai Mineral Products Co., Ltd.; the rest is the same as in Embodiment 1.

[0109] Example 4

[0110] The difference between this embodiment and Embodiment 1 is that the raw materials for the intermediate barrier layer use the same proportions of calcium carbonate with a particle size of 800 mesh (produced by Jiangxi Hengshengtai Co., Ltd.) and talc powder with a particle size of 1000 mesh (Shandong Kaiwei); the rest is the same as in Embodiment 1.

[0111] Example 5

[0112] The difference between this embodiment and Embodiment 1 is that inorganic filler B is not added to the raw materials of the intermediate barrier layer, that is, calcium carbonate and talc are not added; the rest is the same as in Embodiment 1.

[0113] Example 6

[0114] The difference between this embodiment and Embodiment 1 is that no bonding layer material is prepared, that is, the prepared composite film only has an intermediate barrier layer and a heat-sealing protective layer; the rest is the same as Embodiment 1.

[0115] It should be noted that when there is no bonding layer, during the blown film forming process, only double-layer extrusion is required during the extrusion process using an extruder, and the thickness ratio of the intermediate barrier layer to the heat-sealing protective layer is also 4:3, the total thickness of the composite film is also 30μm, and other aspects remain unchanged.

[0116] Example 7

[0117] The difference between this embodiment and Embodiment 1 is that no intermediate barrier layer material is prepared; that is, the prepared composite film only contains a bonding layer and a heat-sealing protective layer. Everything else is the same as in Embodiment 1.

[0118] It should be noted that when there is no intermediate barrier layer, during the blown film forming process, only double-layer extrusion is required during the extrusion process using an extruder, and the thickness ratio of the bonding layer and the heat-sealing protective layer is also 1:1, and the total thickness of the composite film is also 30μm, with everything else remaining unchanged.

[0119] Comparative Example 1

[0120] The difference between this comparative example and Example 1 is that no anti-stick material is added to the raw materials of the heat-sealing anti-stick layer, that is, no siloxane polymer is added; otherwise, it is the same as Example 1.

[0121] Comparative Example 2

[0122] The difference between this comparative example and Example 1 is that the heat-sealing anti-stick layer does not contain anti-stick material or inorganic filler A, that is, it does not contain siloxane polymer or silicon dioxide; the rest is the same as Example 1.

[0123] Comparative Example 3

[0124] The difference between this comparative example and Example 1 is that ultra-high molecular weight polyethylene is not added to the raw materials of the heat-sealing anti-stick layer, that is, MIPELON PM200 is not added; otherwise, it is the same as Example 1.

[0125] Comparative Example 4

[0126] The blister packaging used in this comparative example is the standard structure OP / AL20 / HSL4GSM.

[0127] The specific preparation process of the standard structure is as follows: Select aluminum foil (Henan Mingtai Aluminum Industry, H18 series, alloy grade 8011, thickness 20um) and unwind it. Coat it with heat-sealing adhesive (Shanghai Weikai VC1100A) with a wet coating amount of 20 grams. After drying in an oven, cool it and then coat it with OP protective varnish (Shanghai Weikai OP1302D) with a wet coating amount of 3 grams to obtain the standard PTP cover film with the following structure.

[0128] Comparative Example 5

[0129] This comparative example uses a common composite PE film, and the formulation is shown in Table 9:

[0130] Table 9. Formulation of Common Composite PE Film

[0131]

[0132] Other processing conditions are the same as in Example 1, including blown film forming, aluminum foil lamination, and candy packaging.

[0133] It should be noted that 2420H and 2426H are low-density polyethylene resins produced by Sinopec; 1002KW is linear low-density polyethylene resin produced by ExxonMobil.

[0134] Test case

[0135] 1. Experimental Construction Method

[0136] The aluminum foil composite films containing aluminum foil structures prepared in all the above embodiments and comparative examples were tested for burst strength, contact angle, and anti-stick properties. The specific test methods are as follows:

[0137] (1) Bursting strength test method: Refer to GB / T 454-2020 "Determination of bursting strength of paper". Cut the film into 100×100mm specimens. The specimens should not have creases, wrinkles, visible cracks or other obvious damage. Place the specimens on the testing instrument, and the machine gradually applies pressure until the specimens break. Record the maximum force value when the specimens break. The test result is the average of 10 valid results, which is the bursting strength of the film. Blister packaging is usually opened from the inside out, and the bursting strength is the force value in this direction.

[0138] (2) Contact angle test method: Referring to GB / T 32652-2016 "Method for measuring contact angle of thin films and thin film materials", the water-in-oil gel candy was heated to 70°C to melt it into a liquid state. 10 microliters of liquid were quantitatively dripped onto the surface of the composite film (heat-sealing anti-stick layer). The side image of the droplet formed on the film surface was taken by the contact angle measuring instrument, and the contact angle of the droplet on the contact film surface was analyzed. Each test object was tested three times and the average value was taken.

[0139] (3) Anti-sticking performance test method: Water-in-oil gel candy (liquid) is poured into a cold-formed aluminum blister pack and heat-sealed using the prepared aluminum-plastic composite film (to prevent moisture loss from the candy), so that the candy and the composite film (heat-sealed anti-sticking layer) are in complete contact; after the candy is placed at 40℃ for 240h, it is completely cooled to room temperature (25℃, cooled for more than 4h), the composite film material is opened, and the degree of adhesion between the composite film material and the candy is checked (by the number of adhered particles), and reference is made to Figure 5 To determine different degrees of adhesion.

[0140] 2. Experimental Results

[0141] The test results of the composite films prepared in all the above embodiments and comparative examples regarding burst strength, contact angle, and anti-sticking performance are shown in Table 10.

[0142] Table 10 Test data of burst strength, contact angle, and anti-stick properties of aluminum-plastic composite films in the examples and comparative examples.

[0143]

[0144] As shown in Table 10, the contact angle between the pre-coated aluminum foil (Comparative Example 4) and the water-in-oil gel candy (liquid) is 65~75°, the contact angle between the ordinary composite film (Comparative Example 5) and the candy (liquid) is 70~80°, and the contact angle between the composite film of this patent (Examples 1~7) and the candy (liquid) is improved to 80~95°.

[0145] After packaging candies with pre-coated adhesive aluminum foil, ordinary composite film, and the composite film of this patent, and then treating them at a constant temperature of 40℃ for 240 hours (10 days), and opening them after cooling to room temperature, the candies packaged with the composite film of this patent showed no obvious adhesion, with a low adhesion rate. The adhesion rate of the pre-coated adhesive aluminum foil and ordinary composite film was 100% (Comparative Example 4 and Comparative Example 5). Furthermore, it can be seen from... Figure 2 As can be seen, in Comparative Example 4, the adhesion between the candy and the inner layer of the blister pack is more severe, while from... Figure 3 and Figure 4 As can be seen, in Examples 1 and 2, there was virtually no adhesion between the candy and the inner layer of the blister pack. Furthermore, the composite film of this patent has moderate burst strength, making it easy to puncture or tear while also preventing breakage during packaging or other transportation processes, which would be detrimental to processing and the protection and preservation of the candy.

[0146] Furthermore, the heat-sealing anti-stick layer of the composite film in Comparative Example 1 does not contain anti-stick material (siloxane polymer), the heat-sealing anti-stick layer in Comparative Example 2 does not contain either anti-stick material (siloxane polymer) or inorganic filler (silica), and the heat-sealing anti-stick layer in Comparative Example 3 does not contain ultra-high molecular weight polyethylene. All of these factors resulted in a decrease in the anti-stick performance of the composite film after packaging candies (the contact angle was significantly reduced). This indicates that these materials have a significant impact on the anti-stick performance of the composite film, especially on the formation of micro-nano surface bumps, thus affecting the anti-stick performance of the composite film.

[0147] Furthermore, comparing Example 1 and Example 3, the inorganic filler A in the heat-sealing barrier layer of Example 3 has an excessively large particle size and a large specific surface area, which will cause the candy to stick to the inorganic filler, resulting in a decrease in the anti-sticking performance of the aluminum foil composite film.

[0148] Comparing Example 1 and Example 4, the inorganic filler B in the intermediate barrier layer of Example 4 has a relatively small mesh size and a large particle size, which will reduce the burst strength of the aluminum foil composite film. It will also affect the raised surface of the heat-sealing layer, thereby worsening the adhesion and reducing the contact angle, resulting in a decrease in the anti-sticking performance of the aluminum foil composite film.

[0149] Comparing Example 1 and Example 5, the intermediate barrier layer in Example 5 does not contain inorganic filler B, which will greatly increase the burst strength. At the same time, the PE is sticky, and the customer cannot open the aluminum foil composite film well.

[0150] Comparing Example 1 and Example 6, the composite film of Example 6 has no bonding layer. Although it still has good anti-stick properties, in actual application, the composite film without a bonding layer does not have a good bonding effect with aluminum foil and is prone to delamination. This makes the aluminum foil composite film more prone to breakage, which will have a certain negative impact on actual packaging.

[0151] Comparing Example 1 and Example 7, the composite film of Example 7 does not have an intermediate barrier layer. Without this barrier layer, firstly, it will affect the burst strength and opening effect, and secondly, it cannot affect the surface micro-nano structure of the heat-sealing layer, thus greatly reducing the anti-sticking effect.

[0152] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention, but such modifications or substitutions are all within the scope of protection of the present invention.

Claims

1. A composite film, characterized by: The heat-seal release layer comprises a release material, inorganic filler A, polyolefin A, and ultra-high molecular weight polyethylene; the release material comprises an organosilicon compound; the organosilicon compound comprises a siloxane polymer; The D50 of the inorganic filler A is 1-10 μm; the inorganic filler A comprises silicon dioxide; The mass ratio of the release material, the inorganic filler A, the polyolefin A, and the ultra-high molecular weight polyethylene is 2-30:1-10:50-80:1-10; The polyolefin A comprises at least one of polyethylene and polypropylene; When the polyolefin A comprises the polyethylene, the mass ratio of low-density polyethylene and metallocene polyethylene is 20-60:20-60; or, the polyethylene comprises the low-density polyethylene and linear low-density polyethylene A, and the mass ratio of the low-density polyethylene and the linear low-density polyethylene A is 20-60:20-60; When the polyolefin A comprises the polypropylene, the mass ratio of homopolymer polypropylene, binary material, and ternary material is 10-30:20-30:40-60; the binary material comprises polyolefin material formed by copolymerization of two monomers; the ternary material comprises polyolefin material formed by copolymerization of three monomers; The intermediate barrier layer comprises inorganic filler B and polyolefin B, and the mass ratio of the inorganic filler B and the polyolefin B is 10-80:20-90.

2. The composite film of claim 1, wherein: In the heat-seal release layer, the particle size of the ultra-high molecular weight polyethylene is 1-40 μm.

3. The composite film of claim 1, wherein: In the intermediate barrier layer, the inorganic filler B comprises at least one of calcium carbonate, talc, mica, and silicon dioxide, and the particle size of the inorganic filler B is not less than 1250 mesh; The polyolefin B comprises at least one of polyethylene and polypropylene.

4. The composite film of claim 3, wherein: The intermediate barrier layer further comprises first compatibilizer and lubricant, and the mass ratio of the inorganic filler B, the polyolefin B, the first compatibilizer, and the lubricant is 10-80:20-90:1-10:0-5; The first compatibilizer comprises at least one of maleic anhydride modified polyolefin and acrylic acid modified polyolefin; The lubricant comprises at least one of calcium stearate, magnesium stearate, and polyethylene wax.

5. The composite film of claim 1, wherein: The bonding layer comprises polyolefin C and second compatibilizer, and the mass ratio of the polyolefin C and the second compatibilizer is 10-90:10-90.

6. A packaging material, characterized by: The composite film is adhered to an aluminum foil by an adhesive.

7. A gel confectionery packaging arrangement characterised in that: The gummy candy is packaged in a blister sealed by the packaging material of claim 6.

8. Use of the composite film of any one of claims 1-5 in packaging.

9. Use of the composite film of any one of claims 1-5 in packaging of gummy candy.

10. Use of the composite film according to claim 9 for the packaging of gummy candies, characterized in that, The method comprises the following steps: Step one: preparing an aluminum-containing composite hard sheet material preformed blister by cold forming process; Step two, pouring the gummy candy raw materials into the aluminum-containing composite hard sheet material preformed blister, and then heat sealing the composite film on the aluminum-containing composite hard sheet material preformed blister; wherein the heat sealing of the composite film is performed with the heat sealing release layer of the composite film and the aluminum-containing composite hard sheet material preformed blister.

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