A preparation method for preparing a low-temperature easy-to-peel jelly cover film

Abstract

The application discloses a preparation method for preparing a low-temperature jelly cover film, which comprises the following steps: brushing a high-temperature-resistant boiling-resistant ink layer on the surface of a food-grade PET printing film, coating a first high-temperature-resistant boiling-resistant double-component adhesive layer on one side of the food-grade PET printing film, hot-pressing and compounding a food-grade PET composite film on the food-grade PET printing film to form a semi-finished product composite film, performing three drying treatments on the semi-finished product composite film, smearing a second high-temperature-resistant boiling-resistant double-component adhesive layer on one side of the semi-finished product composite film, hot-pressing and compounding a shearable PE film on the side of the semi-finished product composite film coated with the second high-temperature-resistant boiling-resistant double-component adhesive layer to form a composite film, performing three drying treatments on the composite film, and performing extrusion compounding on the composite film after the second drying treatment and the extrusion compounding PE film on a laminating roller. The jelly cover film prepared by the preparation method is suitable for jelly low-temperature storage and facilitates jelly low-temperature storage.

Description

Technical Field

[0001] This invention relates to the field of jelly cap film technology, and more particularly to a method for preparing a jelly cap film that is suitable for low temperatures and easy to peel off. Background Technology

[0002] A lid film is a composite film that can be sealed to the top of containers (such as cups, jars, bottles, and boxes). Currently available lid films are mainly used on yogurt cups or jelly cups.

[0003] The existing cap film structure is mainly composed of NY / PE / extruded PE. The outer substrate of the cap film structure is NY. NY is easy to absorb water as a printing film, has poor dimensional stability, poor low temperature resistance, poor antistatic properties, and poor heat resistance. However, jelly products require high temperature production and low temperature storage. Therefore, the existing cap film structure is not suitable for the low temperature storage of jelly, which brings great inconvenience to the storage of jelly.

[0004] Furthermore, the existing film cover is not easy to peel off. It requires cutting tools to cut the film before it can be peeled off, which makes it inconvenient to peel off the jelly cover and causes inconvenience to consumers. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a jelly cover film that is suitable for low-temperature storage of jelly, facilitates jelly storage, is easy to open without the need for tools, and is convenient for consumers to eat jelly.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a method for preparing a low-temperature easy-to-peel jelly cap film, including a method for processing and preparing the jelly cap film. The structure of the jelly cap film, from the outside to the inside, consists of a food-grade PET printing film, a high-temperature boil-resistant ink layer, a first high-temperature boil-resistant two-component adhesive layer, a food-grade PET composite film, a second high-temperature boil-resistant two-component adhesive layer, an easy-to-cut PE film, and an extruded and heat-sealed PE film. The method for preparing the jelly cap film includes the following steps:

[0008] Step S1) Printing process: A layer of high-temperature resistant water-boiling ink is brushed onto the surface of the food-grade PET printing film;

[0009] Step S2) First Lamination Process: After printing the high-temperature resistant water-boiling ink layer on the food-grade PET printing film, a first high-temperature resistant water-boiling two-component adhesive layer is coated on one side of the food-grade PET printing film. After applying the first high-temperature resistant water-boiling two-component adhesive layer for 15 seconds, it is dried. Then, the food-grade PET composite film is hot-pressed onto the side of the food-grade PET printing film coated with the first high-temperature resistant water-boiling two-component adhesive layer to form a semi-finished composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa, and the pressure required for bonding the food-grade PET composite film and the food-grade PET printing film is 0.4 MPa.

[0010] Step S3) First drying treatment: The semi-finished composite film obtained in step S2 is sent into the drying oven. The semi-finished composite film is sent to the three drying channels of the drying oven for three drying treatments. The temperatures of the three drying channels are 60℃, 75℃ and 85℃ respectively. The speed of the semi-finished composite film in the three drying channels is 120M / min. The pressure required for the winding guide roller to wind the semi-finished composite film is 0.3Mpa.

[0011] Step S4) Second lamination process: Apply a second layer of high-temperature resistant two-component adhesive to one side of the semi-finished composite film after the first drying process. After applying the second layer of high-temperature resistant two-component adhesive for 15 seconds, allow it to dry. Then, hot-press the easy-to-cut PE film onto the side of the semi-finished composite film coated with the second layer of high-temperature resistant two-component adhesive to form a composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa. The pressure required for hot-pressing the easy-to-cut PE film and the semi-finished composite film is 0.4 MPa.

[0012] Step S5) Second drying process: The composite film obtained in step S4 is sent into the drying oven and dried three times in three drying tunnels. The temperatures of the three drying tunnels are 60℃, 75℃ and 85℃ respectively. The conveying speed of the composite film in the drying tunnel is 120M / min. The pressure required for the winding guide roller to wind the composite film is 0.3Mpa.

[0013] Step S6) Third lamination process: After the second drying process, the composite film is extruded and laminated with the extruded heat-bonded PE film on the lamination roller under the action of the lamination roller.

[0014] To further improve the above technical solution, the extrusion lamination process of the composite film and the extruded heat-sealed PE film in step S6) specifically includes the following steps:

[0015] Step a) Unfolding the substrate: Using the composite film obtained after laminating the easily shearable PE film as the substrate to be laminated, place the substrate to be laminated on the unwinding guide roller of the extrusion laminator and unfold the substrate to be laminated through the unwinding guide roller of the extrusion laminator.

[0016] Step b) Hot melting of resin particles: Mix the three resin particles "PT1450:8200:1C7A" in a ratio of 100:16:5 and put them into resin particle A bucket of the extrusion machine. Then mix the two resin particles "PT1450:1C7A" in a ratio of 100:5 and put them into resin particle B bucket of the extrusion machine. The resin particles in resin particle A bucket and resin particle B bucket are heated by the high temperature heating and melting device of the extrusion machine, so that the resin particles in resin particle A bucket and resin particle B bucket are heated and melted into a resin hot melt film.

[0017] Step c) Extrusion Coating: The substrate to be extruded and laminated is fed into the unwinding guide roller of the extrusion machine. The tension required for the unwinding guide roller to pull the substrate to be laminated is 13 kgf. At the same time, the resin hot melt film heated by the high-temperature heating and melting device is extruded from the die of the extrusion machine to form an extruded heat-sealed PE film. The temperature of the extrusion die of the extrusion machine is 210-290℃. The extruded heat-sealed PE film has two sides, A and B. Side A of the extruded heat-sealed PE film is bonded to the substrate to be laminated, and side B of the extruded heat-sealed PE film directly serves as the inner surface of the whole material, i.e., the heat-sealed cover. After the extruded heat-sealed PE film and the substrate to be laminated are extruded and bonded, a jelly cover film is formed. The jelly cover film is conveyed to the winding device along the guide roller by the bonding roller, thereby completing the production process of the jelly cover film. The temperature required for the bonding roller bonding process is 18℃, and the winding tension required for the winding device to wind the jelly cover film is 20 kgf.

[0018] To further improve the above technical solution, in step S1), a food-grade PET printing film layer is selected as the substrate for printing the high-temperature resistant water-boiling ink layer. This film has high surface wetting tension and excellent tensile strength. The thickness of the food-grade PET printing film layer used as the printing substrate is 12 micrometers, and its density is 1.38 g / cm³. 3 The tensile strength is between 50-60 MPa, and the heat shrinkage rate is less than 5%.

[0019] To further improve the above technical solution, the high-temperature resistant water-boiling ink layer mentioned in step S1) includes the following components in parts by weight: 40-50 parts of silicone resin, 5-12 parts of cashew phenolic resin, 15-27 parts of solvent, 5-10 parts of curing agent, and 3-5 parts of additives. Weigh each component according to the above parts by weight to prepare the high-temperature resistant water-boiling ink layer.

[0020] To further improve the above technical solution, the model and ratio of the first and second high-temperature resistant two-component adhesive layers used in steps S2) and S4) are: main agent XH-66F: curing agent XH-K75: ethyl acetate solvent = 20:3.8:26.

[0021] To further improve the above technical solution, in step S2), when performing the first composite process, a food-grade PET composite film is selected as the intermediate layer, and the thickness of the selected food-grade PET composite film is 12 micrometers.

[0022] To further improve the above technical solution, the PE film selected in the second composite treatment in step S4) has a three-layer film structure, which includes a first layer, a second layer, and a third layer. The first layer accounts for 30%, the second layer accounts for 40%, and the third layer accounts for 30%. The first layer is 100% linear medium-density polyethylene, the second layer is 85% low-pressure high-density polyethylene + 15% high-pressure low-density polyethylene, and the third layer is 81% medium-density metallocene polyethylene, 15% high-pressure low-density polyethylene, 2% opening agent, and 2% slip agent.

[0023] As a further improvement to the above technical solution, the material density of the easily shearable PE film is 0.938 g / cm³. 3 The melt flow index (MI) is 7 g / 10 min, and the thickness is 28 micrometers.

[0024] Compared with the prior art, the solution of the present invention has at least the following beneficial effects:

[0025] (1) The preparation method of the jelly cover film of the present invention includes brushing a layer of high-temperature resistant water-boiling ink onto the surface of a food-grade PET printing film, coating one side of the food-grade PET printing film with a first layer of high-temperature resistant water-boiling two-component adhesive, hot-pressing a food-grade PET composite film onto the side of the food-grade PET printing film coated with the first layer of high-temperature resistant water-boiling two-component adhesive to form a semi-finished composite film, sending the semi-finished composite film to three drying tunnels of an oven for three drying treatments, coating one side of the semi-finished composite film after the first drying treatment with a second layer of high-temperature resistant water-boiling two-component adhesive, and then easily shearing... The PE film is hot-pressed onto one side of a semi-finished composite film coated with a second layer of high-temperature resistant, water-resistant, two-component adhesive to form a composite film. The composite film is then sent to three drying tunnels in an oven for three drying processes. After the second drying process, the composite film is extruded and heat-sealed onto a PE film on a laminating roller to complete the preparation of the jelly cover film. The jelly cover film prepared using this invention is suitable for low-temperature storage of jelly, facilitating this process. Furthermore, the prepared jelly cover film is easy to open, requiring no tools from the consumer, making it convenient for opening and consuming the jelly. This technology addresses the shortcomings of existing jelly cover films, such as their unsuitability for low-temperature storage, difficulty in opening, and the inconvenience they cause to consumers.

[0026] (2) The reason why this invention selects a food-grade PET printing film as the substrate for printing the high-temperature boil-resistant ink layer in the jelly capping process is that the food-grade PET printing film is odorless and non-toxic, has good hygiene performance, good transparency, gloss, high surface wetting tension, excellent tensile strength, is easy to register colors, and has good printability. The selected food-grade PET printing film has a thickness of 12 micrometers and a density of 1.38 g / cm³. 3 With a tensile strength between 50-60 MPa and a heat shrinkage rate of less than 5%, food-grade PET printing film of this specification has excellent polar tensile properties and thermal processability.

[0027] (3) In the first lamination process of the jelly cover film, the reason why the food-grade PET composite film is selected as the middle layer of the semi-finished composite film is mainly because the food-grade PET composite film is made of PET material, which has excellent mechanical properties. Its toughness is the best among all thermoplastic plastics. Its tensile strength and impact strength are much higher than those of ordinary films. It also has good stiffness, which can improve the rigidity of the overall material and make it easier to cut.

[0028] (4) In the preparation of the jelly cover film, the present invention selects an easy-to-cut PE film and a semi-finished composite film to form a composite film. After high-temperature sterilization, the film surface can be made as smooth as a mirror, with a neat appearance and good performance. It also makes the cover film easy to cut during use. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the process for preparing the jelly cap film according to the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the jelly cover film according to the present invention;

[0031] Figure 3 This is a schematic diagram illustrating the usage of the extrusion machine according to the present invention.

[0032] In the diagram, 1 is a jelly cap film, 11 is a food-grade PET printing film, 12 is a high-temperature resistant water-boiling ink layer, 13 is a first high-temperature resistant water-boiling two-component adhesive layer, 14 is a food-grade PET composite film, 15 is a second high-temperature resistant water-boiling two-component adhesive layer, 16 is an easily shearable PE film, 17 is an extruded and heat-sealed PE film, 18 is a substrate to be laminated, 2 is an extrusion machine, 21 is a resin particle A bucket, 22 is a resin particle B bucket, 23 is a high-temperature heating and melting device, 24 is a barrel die, 25 is an unwinding guide roller, 26 is a guide roller, and 27 is a laminating roller. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figures 1-3 As shown, the present invention provides a preparation method for a low-temperature easy-to-peel jelly cover film 1, including a preparation method for processing the jelly cover film 1. The structure of the jelly cover film 1 of the present invention, from the outside to the inside, consists of a food-grade PET printing film 11, a high-temperature resistant water-boiling ink layer 12, a first high-temperature resistant water-boiling two-component adhesive layer 13, a food-grade PET composite film 14, a second high-temperature resistant water-boiling two-component adhesive layer 15, an easy-to-cut PE film 16, and an extruded and heat-sealed PE film 17. The preparation method of the jelly cover film 1 includes the following steps:

[0035] Step S1) Printing process: A layer of high temperature resistant water-boiling ink 12 is brushed onto the surface of the food-grade PET printing film 11. The thickness of the high temperature resistant water-boiling ink 12 is 1 micrometer, which facilitates the printing of product patterns on the food-grade PET printing film 11.

[0036] Step S2) First Lamination Process: After the food-grade PET printing film 11 is printed with the high-temperature resistant water-boiling ink layer 12, a first high-temperature resistant water-boiling two-component adhesive layer 13 is coated on one side of the food-grade PET printing film 11. After the first high-temperature resistant water-boiling two-component adhesive layer 13 is coated for 15 seconds, it is dried. Then, the food-grade PET composite film 14 is hot-pressed onto the side of the food-grade PET printing film 11 coated with the first high-temperature resistant water-boiling two-component adhesive layer 13 to form a semi-finished composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa, and the pressure required for bonding the food-grade PET composite film 14 and the food-grade PET printing film 11 is 0.4 MPa.

[0037] Step S3) First drying treatment: The semi-finished composite film obtained in step S2 is sent into the drying oven. The semi-finished composite film is sent to the three drying channels of the drying oven for three drying treatments. The temperatures of the three drying channels are 60℃, 75℃ and 85℃ respectively. The speed of the semi-finished composite film in the three drying channels is 120M / min. The pressure required for the winding guide roller to wind the semi-finished composite film is 0.3Mpa.

[0038] Step S4) Second lamination process: Apply a second layer of high-temperature resistant two-component adhesive 15 to one side of the semi-finished composite film after the first drying process. After applying the second layer of high-temperature resistant two-component adhesive 15 for 15 seconds, allow it to dry. Then, hot-press the easily shearable PE film 16 onto the side of the semi-finished composite film coated with the second layer of high-temperature resistant two-component adhesive 15 to form a composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa. The pressure required for hot-pressing the easily shearable PE film 16 and the semi-finished composite film is 0.4 MPa.

[0039] Step S5) Second drying process: The composite film obtained in step S4 is sent into the drying oven and dried three times in three drying tunnels. The temperatures of the three drying tunnels are 60℃, 75℃ and 85℃ respectively. The conveying speed of the composite film in the drying tunnel is 120M / min. The pressure required for the winding guide roller to wind the composite film is 0.3Mpa.

[0040] Step S6) Third lamination process: After the second drying process, the composite film is extruded and laminated with the extruded heat-bonded PE film 17 on the lamination roller 27 under the action of the lamination roller 27. The specific operation of the extrusion lamination process of the composite film and the extruded heat-bonded PE film 17 includes the following steps:

[0041] Step a) Unfolding the substrate: The composite film obtained after laminating the easily shearable PE film 16 is used as the substrate to be laminated 18. The substrate to be laminated 18 is placed on the unwinding guide roller 25 of the extrusion laminator 2 and unfolded by the unwinding guide roller 25 of the extrusion laminator 2.

[0042] Step b) Hot melting of resin particles: Mix the three resin particles "PT1450:8200:1C7A" in a ratio of 100:16:5 and put them into resin particle A tank 21 of extrusion machine 2. Then mix the two resin particles "PT1450:1C7A" in a ratio of 100:5 and put them into resin particle B tank 22 of extrusion machine 2. The resin particles in resin particle A tank 21 and resin particle B tank 22 are heated by the high temperature heating and melting device 23 of extrusion machine 2, so that the resin particles in resin particle A tank 21 and resin particle B tank 22 are heated and melted into a resin hot melt film.

[0043] Step c) Extrusion Coating: The substrate 18 to be extruded and laminated is fed into the unwinding guide roller 25 of the extrusion machine 2. The tension required for the unwinding guide roller 25 to pull the substrate 18 to be laminated is 13 kgf. At the same time, the resin hot melt film heated by the high-temperature heating and melting device 23 is extruded from the die head 24 of the extrusion machine 2 to form an extruded heat-sealed PE film 17. The temperature of the die head 24 of the extrusion machine 2 is 210-290℃. The extruded heat-sealed PE film 17 has two sides, A and B. The A side of the film 17 is bonded to the substrate 18 to be laminated, and the B side of the extruded and heat-sealed PE film 17 is directly used as the inner surface of the whole material, i.e., the heat-sealed cover. After the extruded and heat-sealed PE film 17 and the substrate 18 to be laminated are extruded and bonded, a jelly cover film 1 is formed. The jelly cover film 1 is conveyed to the winding device along the guide roller 26 via the bonding roller 27, thereby completing the manufacturing process of the jelly cover film 1. The temperature required for the bonding roller 27 to bond is 18°C, and the winding tension required for the winding device to wind the jelly cover film 1 is 20 kgf.

[0044] The temperature of the die head 24 of the resin particle A barrel 21 and resin particle B barrel 22 of the present invention is 210-290℃, as shown in Table 1 below. The resin particles in the resin particle A barrel 21 and resin particle B barrel 22 are heated by the die head 24, so that the resin particles change from solid to fluid and are poured out through the die head 24.

[0045] Barrel and die head temperatures (unit: °C)

[0046] A-C1 A-C2 A-C3 A-C4 A-C5 A-C6 A-H A-A A-J 210 250 260 270 280 285 285 285 280 A-D1 A-D2 A-D3 A-D4 A-D5 A-D6 A-D7 A-D8 A-D9 290 290 290 280 280 280 290 290 290 B-C1 B-C2 B-C3 B-C4 B-C5 B-C6 B-H B-A B-J 210 250 260 270 280 285 285 285 280 B-D1 B-D2 B-D3 B-D4 B-D5 B-D6 B-D7 B-D8 B-D9 290 290 290 280 280 280 290 290 290

[0047] In the specific implementation of this invention, the reason why food-grade PET printing film 11 layers are selected as the printing substrate for the high-temperature resistant water-boiling ink layer 12 in the process of printing the jelly cover film 1 is because food-grade PET printing film 11 layers are odorless and non-toxic, have good hygiene performance, good transparency, gloss, high surface wetting tension, excellent tensile strength, easy color registration, and good printability. The selected food-grade PET printing film 11 layers are used as the printing substrate, with a thickness of 12 micrometers and a density of 1.38 g / cm³. 3 With a tensile strength between 50-60 MPa and a heat shrinkage rate of less than 5%, this type of 11-layer food-grade PET printing film exhibits excellent polar tensile properties and thermal processability.

[0048] The high-temperature resistant water-boiling ink layer 12 of the present invention comprises the following components in parts by weight: 40-50 parts of silicone resin, 5-12 parts of cashew phenolic resin, 15-27 parts of solvent, 5-10 parts of curing agent, and 3-5 parts of additives. Specifically, 40 parts of silicone resin, 5 parts of cashew phenolic resin, 15 parts of solvent, and 3 parts of additives can be mixed and dispersed at a low speed of 300 rpm using a disperser for 10 minutes. After that, the dispersion is further dispersed at a speed of 2050 rpm for 10 minutes. The speed is then adjusted to 1500 rpm, and 5 parts of curing agent are added. After 20 minutes, the mixture is heated to 70°C at a rate of 8°C / min to obtain the high-temperature resistant water-boiling ink layer 12. In the process of preparing the high-temperature resistant water-boiling ink layer 12, an appropriate amount of curing agent is added. The curing agent can prevent the high-temperature resistant water-boiling ink layer 12 from peeling off under high temperature. Since the jelly needs to be boiled during the production process, the selected high-temperature resistant water-boiling ink layer needs to be suitable for high-temperature environments. Therefore, the present invention selects water-resistant polyurethane ink as the high-temperature resistant water-boiling ink layer 12 of the present invention.

[0049] In the specific implementation of this invention, the first high-temperature resistant two-component adhesive layer 13 and the second high-temperature resistant two-component adhesive layer 15 used in steps S2) and S4) are of the following types and ratios: main agent XH-66F: curing agent XH-K75: ethyl acetate solvent = 20:3.8:26. The working solution concentration of the adhesive prepared using this type and ratio is 30%, the solid content is 30%, and the adhesive viscosity is 16-18s (25℃, 3# Zahn cup). The solid content of the first high-temperature resistant two-component adhesive layer 13 and the second high-temperature resistant two-component adhesive layer 15 is moderate and not too hard, which can prevent the food-grade PET printing film 11 from hardening.

[0050] In step S2) of this invention, the reason why a food-grade PET composite film 14 is chosen as the intermediate layer during the first lamination process, and the thickness of the selected food-grade PET composite film 14 is 12 micrometers, is mainly because the food-grade PET composite film 14 uses PET material, which has excellent mechanical properties. Its toughness is the best among all thermoplastics, and its tensile strength and impact strength are much higher than those of ordinary films. It also has good stiffness, which can improve the overall rigidity of the material and make it easier to cut.

[0051] In step S4) of this invention, the shearable PE film selected for the second lamination process has a three-layer film structure, comprising a first layer, a second layer, and a third layer. The first layer is 100% linear medium-density polyethylene (MDPE), the second layer is 85% low-density polyethylene (HDPE) and 15% high-density polyethylene (HDPE), and the third layer is 81% MMDPE, 15% HDPE, 2% opening agent, and 2% slip agent. The first layer accounts for 30%, the second layer for 40%, and the third layer for 30%. The material density of the selected shearable PE film is 0.938 g / cm³. 3 With a melt flow index (MI) of 7 g / 10 min and a thickness of 28 micrometers, the use of this type of easy-to-cut PE film ensures the resilience of the material. After high-temperature sterilization, the resulting composite film will shrink, making the cover surface smooth like a mirror, with a neat appearance and good performance. It also makes the cover film easy to cut during use.

[0052] I. The present invention will be further described below with reference to four specific embodiments provided by the present invention:

[0053] 1. In a specific embodiment of the present invention, the jelly cap film 1 of the present invention can be prepared and processed using the following film layers, and the specific film layer structures are shown in Table 2 below:

[0054]

[0055]

[0056] Table 2

[0057] 2. In a specific embodiment two of the present invention, the jelly cap film 1 of the present invention can be prepared by the following preparation method, which includes the following steps:

[0058] Step S1) Printing process: A layer of high temperature resistant water-boiling ink 12 is brushed onto the surface of the food-grade PET printing film 11. The thickness of the high temperature resistant water-boiling ink 12 is 1 micrometer, which facilitates the printing of product patterns on the food-grade PET printing film 11.

[0059] Step S2) First Lamination Process: After the food-grade PET printing film 11 is printed with the high-temperature resistant water-boiling ink layer 12, a first high-temperature resistant water-boiling two-component adhesive layer 13 is coated on one side of the food-grade PET printing film 11. After coating the first high-temperature resistant water-boiling two-component adhesive layer 13 for 15 seconds, it is dried. Then, the food-grade PET composite film 14 is hot-pressed onto the side of the food-grade PET printing film 11 coated with the first high-temperature resistant water-boiling two-component adhesive layer 13 to form a semi-finished composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa, and the pressure required for bonding the food-grade PET composite film 14 and the food-grade PET printing film 11 is 0.4 MPa.

[0060] Step S3) First drying treatment: The semi-finished composite film obtained in step S2 is sent into the drying oven. The semi-finished composite film is sent to the three drying channels of the drying oven for three drying treatments. The temperatures of the three drying channels are 60℃, 75℃ and 85℃ respectively. The speed of the semi-finished composite film in the three drying channels is 120M / min. The pressure required for the winding guide roller to wind the semi-finished composite film is 0.3Mpa.

[0061] Step S4) Second lamination process: Apply a second layer of high-temperature resistant two-component adhesive 15 to one side of the semi-finished composite film after the first drying process. After applying the second layer of high-temperature resistant two-component adhesive 15 for 15 seconds, allow it to dry. Then, hot-press the easily shearable PE film 16 onto the side of the semi-finished composite film coated with the second layer of high-temperature resistant two-component adhesive 15 to form a composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa. The pressure required for hot-pressing the easily shearable PE film and the semi-finished composite film is 0.4 MPa.

[0062] Step S5) Second drying process: The composite film obtained in step S4 is sent into the drying oven and dried three times in three drying tunnels. The temperatures of the three drying tunnels are 60℃, 75℃ and 85℃ respectively. The conveying speed of the composite film in the drying tunnel is 120M / min. The pressure required for the winding guide roller to wind the composite film is 0.3Mpa.

[0063] Step S6) Third lamination process: After the second drying process, the composite film is extruded and laminated with the extruded heat-bonded PE film 17 on the lamination roller 27 under the action of the lamination roller 27. The specific operation of the extrusion lamination process of the composite film and the extruded heat-bonded PE film 17 includes the following steps:

[0064] Step a) Unfolding the substrate: The composite film obtained after laminating the easily shearable PE film 16 is used as the substrate to be laminated 18. The substrate to be laminated 18 is placed on the unwinding guide roller 25 of the extrusion laminator 2 and unfolded by the unwinding guide roller 25 of the extrusion laminator 2.

[0065] Step b) Hot melting of resin particles: Mix the three resin particles "PT1450:8200:1C7A" in a ratio of 100:16:5 and put them into resin particle A tank 21 of extrusion machine 2. Then mix the two resin particles "PT1450:1C7A" in a ratio of 100:5 and put them into resin particle B tank 22 of extrusion machine 2. The resin particles in resin particle A tank 21 and resin particle B tank 22 are heated by the high temperature heating and melting device 23 of extrusion machine 2, so that the resin particles in resin particle A tank 21 and resin particle B tank 22 are heated and melted into a resin hot melt film.

[0066] Step c) Extrusion Coating: The substrate 18 to be extruded and laminated is fed into the unwinding guide roller 25 of the extrusion machine 2. The tension required for the unwinding guide roller 25 to pull the substrate 18 to be laminated is 13 kgf. At the same time, the resin hot melt film heated by the high-temperature heating and melting device 23 is extruded from the die head 24 of the extrusion machine 2 to form an extruded heat-sealed PE film 17. The temperature of the die head 24 of the extrusion machine 2 is 290°C. The extruded heat-sealed PE film 17 has two sides, A and B. The A side of 17 is bonded to the substrate 18 to be laminated, and the B side of the extruded and heat-sealed PE film 17 is directly used as the inner surface of the whole material, i.e., the heat-sealed cover. After the extruded and heat-sealed PE film 17 and the substrate 18 to be laminated are extruded and bonded, a jelly cover film 1 is formed. The jelly cover film 1 is conveyed to the winding device along the guide roller 26 through the bonding roller 27 to complete the manufacturing process of the jelly cover film 1. The temperature required for the bonding roller 27 to bond is 18°C, and the winding tension required for the winding device to wind the jelly cover film 1 is 20 kgf.

[0067] II. The jelly cap film 1 prepared using Example 2 above was subjected to low-temperature resistance test, shearability test, and peelability test. The specific test results are as follows:

[0068] (I) Low-temperature resistance test on jelly cover film 1

[0069] 1. Test Subjects: The jelly cap film 1 prepared in Example 2 was used for online production on the customer's jelly cup packaging equipment. The jelly cups were filled with a specified weight of jelly and water. After the equipment was debugged and normal, it was continuously produced for about 1 hour. Every 5 minutes, a sample sealed with jelly cap film 1 was randomly selected and each sample was numbered as test point T1, test point T2, test point T3, test point T4, test point T5, test point T6, test point T7, test point T8, test point T9, and test point T10.

[0070] 2. Test method: After filling the jelly cups with water and jelly liquid respectively, produce, sterilize and cool according to normal production process, and then refrigerate at -18℃ for 12 hours. After refrigeration, let it thaw naturally at room temperature or warm it with warm water to about 10-20°C, and check whether the lid film is cracked or delaminated.

[0071] 3. The test results are shown in Table 3 below:

[0072]

[0073] Table 3

[0074] 4. Conclusion: The test results are shown in Table 3 above. Analysis of the test data shows that when water and jelly liquid are filled into jelly cups and sealed with the jelly cover film 1 prepared in Example 2, and then refrigerated at -18°C for 12 hours, the cover film of both the jelly cups containing water and the samples containing jelly liquid shows no cracking or delamination. When the samples containing water and jelly liquid are placed at room temperature to thaw naturally or warmed to about 10-20°C with warm water, the cover film of both the jelly cups containing water and the samples containing jelly liquid shows no cracking or delamination. Therefore, the jelly cover film 1 prepared by the method of this invention has good low-temperature resistance.

[0075] (II) Shearability test of jelly cover film 1

[0076] 1. Test subject:

[0077] a. Select 20 jelly cups of the same size and fill them with an equal amount of jelly liquid;

[0078] b. Take 10 portions of the jelly cover film 1 prepared in Example 2, and seal 10 jelly cups containing jelly liquid with these 10 portions of jelly cover film 1. Each jelly cup sealed with jelly cover film 1 is used as a test point for the experiment. The jelly cup sealed with jelly cover film 1 has 10 test points, namely jelly cover film 1 test point T1, jelly cover film 1 test point T2, jelly cover film 1 test point T3, jelly cover film 1 test point T4, jelly cover film 1 test point T5, jelly cover film 1 test point T6, jelly cover film 1 test point T7, jelly cover film 1 test point T8, jelly cover film 1 test point T9, and jelly cover film 1 test point T10.

[0079] c. Select 10 portions of traditional capping film (NY / PE / extruded PE) and use these 10 portions of traditional capping film to seal the remaining 10 jelly cups containing jelly liquid. Use each portion of traditional capping film as a test point for the experiment. There are a total of 10 test points, namely traditional capping film test point T1, traditional capping film test point T2, traditional capping film test point T3, traditional capping film test point T4, traditional capping film test point T5, traditional capping film test point T6, traditional capping film test point T7, traditional capping film test point T8, traditional capping film test point T9, and traditional capping film test point T10.

[0080] 2. Test method: The prepared jelly cover film 1 was compared with the traditional cover film in parallel according to GB / T 16578.2-2009 Determination of tear resistance of plastic films and sheets Part 2: Elmendor method.

[0081] 3. The test results are shown in Table 4 below:

[0082]

[0083]

[0084] Table 4

[0085] 4. Conclusion: The test results are shown in Table 4 above. Comparing the tear resistance of the jelly cover film 1 with that of the traditional cover film, it can be seen that the average tear resistance of the traditional cover film is about 955mN, while that of the jelly cover film 1 is about 612mN. The smaller the tear resistance, the better the shearing effect of the jelly cover film 1. This is because the shearing effect of the cover film is mainly reflected in the physical index of the cover film, which is the tear resistance. The smaller the tear resistance, the better the shearing effect of the cover film. Conversely, if the tear resistance is large, the shearing effect of the cover film is poor, and it is easy to clog the knife during the production process. During the consumer's use, the cut end face is flat and there are no burrs, which makes the efficiency of tearing the cover film higher. As can be seen from the test results in Table 4, the jelly cover film 1 prepared by the preparation method of this invention has a better shearing effect.

[0086] (III) Conduct an easy-to-remove test on the jelly cover film 1.

[0087] 1. Test subject:

[0088] a. Select 20 sealing cups of the specified specifications, and fill the sealing cups with an equal amount of jelly liquid. The sealing cups are made of PP (polypropylene).

[0089] b. Take 10 portions of the jelly cap film 1 prepared in Example 2, and use these 10 portions of jelly cap film 1 to heat seal 10 sealing cups containing jelly liquid. Select 10 portions of jelly cap film 1 and 10 sealing cup sheets, and cut each portion of jelly cap film 1 and each sealing cup sheet into strips 15mm wide and 100mm long. Place the jelly cap film 1 on the sealing cup sheet and heat seal using a heat sealer at a temperature of 180℃, a heat sealing time of 1.5 seconds, and a heat sealing pressure of 20kPa. The heat-sealed jelly... After the jelly cap film 1 and the sealing cup are cooled, each sealing cup sealed with the jelly cap film 1 is used as a test point for testing. The sealing cup sealed with the jelly cap film 1 has 10 test points, namely jelly cap film 1 test point T1, jelly cap film 1 test point T2, jelly cap film 1 test point T3, jelly cap film 1 test point T4, jelly cap film 1 test point T5, jelly cap film 1 test point T6, jelly cap film 1 test point T7, jelly cap film 1 test point T8, jelly cap film 1 test point T9, and jelly cap film 1 test point T10.

[0090] c. Select 10 portions of traditional capping film (NY / PE / extruded PE) and use these 10 portions to heat-seal the remaining 10 sealing cups containing the jelly liquid. Select 10 portions of traditional capping film and 10 sealing cup sheets, and cut each portion of traditional capping film and each sealing cup sheet into strips 15mm wide and 100mm long. Place the traditional capping film on the sealing cup sheet and heat-seal using a heat sealer at 180℃, 1.5 seconds, and 20kPa pressure. The heat-sealed cups should be sealed... After the traditional lid film and sealing cups cooled, each sealing cup sealed with the traditional lid film was used as a test point for testing, and each traditional lid film was used as a test point for testing. There were a total of 10 test points, namely, traditional lid film test point T1, traditional lid film test point T2, traditional lid film test point T3, traditional lid film test point T4, traditional lid film test point T5, traditional lid film test point T6, traditional lid film test point T7, traditional lid film test point T8, traditional lid film test point T9, and traditional lid film test point T10.

[0091] 2. Test Method: After the heat-sealed jelly cap film 1 and sealing cup have cooled according to "QBT2358-1998 Test Method for Heat Seal Strength of Plastic Film Packaging Bags", open the jelly cap film 1 and sealing cup to a 180° angle with the heat-sealed part as the center. Clamp both ends of the jelly cap film 1 onto the two clamps of the testing machine. The sample axis should coincide with the center line of the upper and lower clamps, and the tightness should be appropriate to prevent the jelly cap film 1 and sealing cup from slipping or breaking in the clamps before the test. The distance between the clamps is 50 mm, and the test speed is 300 mm / s. / min, read the maximum load when the jelly cover film 1 breaks; after cooling the heat-sealed traditional cover film and sealing cup, open the traditional cover film and sealing cup after state conditioning to 180° with the heat-sealed part as the center, clamp the two ends of the traditional cover film on the two clamps of the testing machine, the sample axis should coincide with the center line of the upper and lower clamps, and the tightness should be appropriate to prevent the traditional cover film and sealing cup from slipping or breaking in the clamps before the test. The distance between the clamps is 50mm, the test speed is 300mm / min, and read the maximum load when the traditional cover film breaks.

[0092] 3. The test results are shown in Table 5 below:

[0093]

[0094] Table 5

[0095] 4. Conclusion: The test results are shown in Table 5 above. Comparing the jelly cap film 1 with the traditional cap film, it can be seen that the average opening force of the traditional cap film and the sealing cup sheet is about 57.N, which requires a large opening force and is difficult to open. The average opening force of the jelly cap film 1 prepared by the present invention and the sealing cup sheet is 23.9N, which is moderate. It can meet the safety of packaging and ensure the sealing safety of the filler. At the same time, the opening force of 23.9N is moderate, and ordinary children can easily open it to eat.

[0096] Based on the above embodiments and test results, it can be seen that the jelly cover film 1 prepared by the preparation method of the present invention can achieve the effects of low temperature resistance, easy cutting, and easy peeling.

[0097] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of this application. All equivalent changes and modifications made in accordance with the scope of this application should still fall within the scope of the present invention.

Claims

1. A method for preparing an easy-to-peel jelly cap film at low temperatures, characterized in that: The invention includes a method for preparing a jelly cap film. The jelly cap film, from the outside to the inside, comprises a food-grade PET printing film, a high-temperature resistant water-boiling ink layer, a first high-temperature resistant water-boiling two-component adhesive layer, a food-grade PET composite film, a second high-temperature resistant water-boiling two-component adhesive layer, an easily shearable PE film, and an extruded and heat-sealed PE film. The method for preparing the jelly cap film includes the following steps: Step S1) Printing treatment: A layer of high-temperature boil-resistant ink is brushed onto the surface of the food-grade PET printing film. The high-temperature boil-resistant ink layer includes the following components in parts by weight: 40-50 parts of silicone resin, 5-12 parts of cashew phenolic resin, 15-27 parts of solvent, 5-10 parts of curing agent, and 3-5 parts of additives. Weigh each component according to the above parts by weight to prepare the high-temperature boil-resistant ink layer. Step S2) First Lamination Process: After printing the high-temperature resistant water-boiling ink layer on the food-grade PET printing film, a first high-temperature resistant water-boiling two-component adhesive layer is coated on one side of the food-grade PET printing film. After applying the first high-temperature resistant water-boiling two-component adhesive layer for 15 seconds, it is dried. Then, the food-grade PET composite film is hot-pressed onto the side of the food-grade PET printing film coated with the first high-temperature resistant water-boiling two-component adhesive layer to form a semi-finished composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa, and the pressure required for bonding the food-grade PET composite film and the food-grade PET printing film is 0.4 MPa. Step S3) First drying treatment: The semi-finished composite film obtained in step S2 is sent into the drying oven. The semi-finished composite film is sent to the three drying channels of the drying oven for three drying treatments. The temperatures of the three drying channels are 60℃, 75℃ and 85℃ respectively. The speed of the semi-finished composite film in the three drying channels is 120M / min. The pressure required for the winding guide roller to wind the semi-finished composite film is 0.3Mpa. Step S4) Second lamination process: Apply a second layer of high-temperature resistant two-component adhesive to one side of the semi-finished composite film after the first drying process. After applying the second layer of high-temperature resistant two-component adhesive for 15 seconds, allow it to dry. Then, hot-press the easy-to-cut PE film onto the side of the semi-finished composite film coated with the second layer of high-temperature resistant two-component adhesive to form a composite film. During the hot-pressing process, hot-pressing guide rollers are used for pressing and bonding. The pressure required for the pressing process is 0.35 MPa. The pressure required for hot-pressing the easy-to-cut PE film and the semi-finished composite film is 0.4 MPa. The first and second high-temperature resistant two-component adhesive layers used are of the following type and ratio: main agent XH-66F: curing agent XH-K75: ethyl acetate solvent = 20: 3.8: 26; The easily shearable PE film selected for the second lamination process has a three-layer film structure, consisting of a first layer, a second layer, and a third layer. The first layer accounts for 30%, the second layer accounts for 40%, and the third layer accounts for 30%. Specifically, the first layer is 100% linear medium-density polyethylene, the second layer is 85% low-pressure high-density polyethylene and 15% high-pressure low-density polyethylene, and the third layer is 81% medium-density metallocene polyethylene, 15% high-pressure low-density polyethylene, 2% opening agent, and 2% slip agent. Step S5) Second drying process: The composite film obtained in step S4 is sent into the drying oven and dried three times in three drying tunnels. The temperatures of the three drying tunnels are 60℃, 75℃ and 85℃ respectively. The conveying speed of the composite film in the drying tunnel is 120M / min. The pressure required for the winding guide roller to wind the composite film is 0.3Mpa. Step S6) Third lamination process: After the second drying process, the composite film is extruded and laminated with the extruded heat-bonded PE film on the lamination roller under the action of the lamination roller.

2. The preparation method for preparing a low-temperature easy-to-peel jelly cap film according to claim 1, characterized in that: The extrusion lamination process of the composite film and the extruded heat-sealed PE film in step S6) specifically includes the following steps: Step a) Unfolding the substrate: Using the composite film obtained after laminating the easily shearable PE film as the substrate to be laminated, place the substrate to be laminated on the unwinding guide roller of the extrusion laminator and unfold the substrate to be laminated through the unwinding guide roller of the extrusion laminator. Step b) Hot melting of resin particles: Mix the three resin particles "PT1450:8200:1C7A" in a ratio of 100:16:5 and put them into resin particle A bucket of the extrusion machine. Then mix the two resin particles "PT1450:1C7A" in a ratio of 100:5 and put them into resin particle B bucket of the extrusion machine. The resin particles in resin particle A bucket and resin particle B bucket are heated by the high temperature heating and melting device of the extrusion machine, so that the resin particles in resin particle A bucket and resin particle B bucket are heated and melted into a resin hot melt film. Step c) Extrusion Coating: The substrate to be extruded and laminated is fed into the unwinding guide roller of the extrusion machine. The tension required for the unwinding guide roller to pull the substrate to be laminated is 13 kgf. At the same time, the resin hot melt film heated by the high-temperature heating and melting device is extruded from the die of the extrusion machine to form an extruded heat-sealed PE film. The temperature of the extrusion die of the extrusion machine is 210-290℃. The extruded heat-sealed PE film has two sides, A and B. Side A of the extruded heat-sealed PE film is bonded to the substrate to be laminated, and side B of the extruded heat-sealed PE film directly serves as the inner surface of the whole material, i.e., the hot-sealed cover. After the extruded heat-sealed PE film and the substrate to be laminated are extruded and bonded, a jelly cover film is formed. The jelly cover film is conveyed to the winding device along the guide roller by the bonding roller. The temperature required for the bonding roller bonding process is 18℃. The winding tension required for the winding device to wind the jelly cover film is 20 kgf.

3. The preparation method for preparing a low-temperature easy-to-peel jelly cap film according to claim 2, characterized in that: In step S1), the food-grade PET printing film layer used as the printing substrate has a thickness of 12 micrometers and a density of 1.38 g / cm³. 3 The tensile strength is between 50-60 MPa, and the heat shrinkage rate is less than 5%.

4. The preparation method for preparing a low-temperature easy-to-peel jelly cap film according to claim 1, characterized in that: In step S2), when performing the first lamination process, a food-grade PET composite film is selected as the intermediate layer, and the thickness of the selected food-grade PET composite film is 12 micrometers.

5. The preparation method for preparing a low-temperature easy-to-peel jelly cap film according to claim 1, characterized in that: The material density of the easily shearable PE film is 0.938 g / cm³. 3 The melt index (MI) is 7 g / 10 min, and the thickness is 28 micrometers.

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