Ultralow-temperature recoverable liquid-washing small packaging film and preparation process thereof

Abstract

The invention belongs to the technical field of packaging films, and particularly relates to an ultralow-temperature recyclable liquid-washing small packaging film and a preparation process thereof. The composite material comprises an MDOPE layer, a VMPE layer and a PE layer which are connected in sequence, wherein the VMPE layer is composed of a first corona layer, a first middle layer and an inner layer which are connected in sequence; the PE layer consists of a second corona layer, a second middle layer and a heat sealing layer which are connected in sequence; the first corona layer is connected with the MDOPE layer after being subjected to an aluminum plating process, and the inner layer is connected with the second corona layer. The liquid-washing small packaging film has high barrier property, can reduce the loss of water in the liquid-washing small packaging film, is made of PE materials from the outer layer to the middle layer to the inner layer, is made of a single PE material, and can be recycled for continuous processing and utilization after being used, so that the pollution to the environment is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the field of packaging films, and in particular relates to an ultra-low temperature recyclable liquid-washable small packaging film and a preparation process thereof. Background Art

[0002] In recent years, with the rapid development of the plastics industry, plastic packaging has been widely used. Plastic packaging materials have greatly facilitated people's lives since the 1970s due to their excellent properties such as light weight, high strength, convenience and low price. However, since most plastic packaging materials cannot be naturally degraded, their packaging waste will become permanent garbage, causing serious pollution to the environment.

[0003] Facts have proved that modern society cannot do without plastic. It is better to guide it than to block it. The only way out is to use materials with better performance-price ratio, use technologies and methods that are more in line with the characteristics of the times to develop degradable plastics, and increase the recycling and reuse of plastic waste.

[0004] At present, the main packaging materials for small liquid washing packages on the market are: PET / PE / VMPET / PE, PET / VMPET / PE, PET / PE. The disadvantage is that the moisture barrier performance is not high. Most materials are composite materials of polyester and polyolefin. The used film is difficult to be recycled and processed, and the discarded composite film will pollute the environment. The outer layer uses PET polyester material with a melting point of more than 245 degrees, and the inner layer uses polyethylene resin with a high sealing temperature (more than 115 degrees). Therefore, its sealing temperature is higher and cannot meet the requirements of high-speed packaging. Summary of the invention

[0005] In order to overcome the defects in the prior art, the present invention provides an ultra-low temperature recyclable liquid-washable small packaging film and a preparation process thereof. The packaging film of the present invention has high moisture barrier performance, can be heat-sealed at low temperature, and has a single material and is recyclable.

[0006] To achieve one of the above purposes, the present invention adopts the following technical solution:

[0007] A super-low temperature recyclable liquid-washable small packaging film, comprising an MDOPE layer, a high-barrier VMPE layer and an super-low temperature PE layer connected in sequence, wherein the high-barrier VMPE layer is composed of a first corona layer, a first intermediate layer and an inner layer connected in sequence; the super-low temperature PE layer is composed of a second corona layer, a second intermediate layer and a heat-sealing layer connected in sequence; the first corona layer is connected to the MDOPE layer after an aluminum plating process, and the inner layer is connected to the second corona layer.

[0008] Preferably, the first corona layer comprises 65-75 parts by weight of the first metallocene polyethylene, 10-20 parts by weight of EAA (ethylene acrylic acid copolymer) and 10-20 parts by weight of low-density polyethylene; the first intermediate layer comprises 65-75 parts by weight of the first high-density polyethylene, 25-35 parts by weight of low-density polyethylene; the inner layer comprises 65-75 parts by weight of the second high-density polyethylene, 15-25 parts by weight of metallocene linear low-density polyethylene and 5-15 parts by weight of low-density polyethylene; the second corona layer The invention comprises 70-80 parts by weight of linear polyethylene and 20-30 parts by weight of low-density polyethylene, the second intermediate layer comprises 55-65 parts by weight of a second high-density polyethylene and 35-45 parts by weight of low-density polyethylene, the heat-sealing layer comprises 25-35 parts by weight of a second metallocene polyethylene, 25-35 parts by weight of metallocene linear low-density polyethylene, 30-40 parts by weight of low-density polyethylene, 2-3 parts by weight of a lubricant, 0.5-1.5 parts by weight of an opening agent and 2-3 parts by weight of a silicone masterbatch.

[0009] Preferably, the first corona layer comprises 70 parts by mass of a first metallocene polyethylene, 15 parts by mass of EAA and 15 parts by mass of a low-density polyethylene; the first intermediate layer comprises 70 parts by mass of a first high-density polyethylene, 30 parts by mass of a low-density polyethylene; the inner layer comprises 70 parts by mass of a second high-density polyethylene, 20 parts by mass of a metallocene linear low-density polyethylene and 10 parts by mass of a low-density polyethylene; the second corona layer comprises 75 parts by mass of a linear polyethylene, 25 parts by mass of a low-density polyethylene, the second intermediate layer comprises 60 parts by mass of a second high-density polyethylene and 40 parts by mass of a low-density polyethylene, and the heat-sealing layer comprises 30 parts by mass of a second metallocene polyethylene, 30 parts by mass of a metallocene linear low-density polyethylene, 34 parts by mass of a low-density polyethylene, 2.5 parts by mass of a lubricant, 1 part by mass of an opening agent and 2.5 parts by mass of a silicone masterbatch.

[0010] Preferably, the thickness ratio of the first corona layer, the first intermediate layer and the inner layer is 1:2:1; the thickness ratio of the second corona layer, the second intermediate layer and the heat sealing layer is 1:2:1; the thickness ratio of the MDOPE layer, the high barrier VMPE layer and the ultra-low temperature PE layer is 5:9:12.

[0011] Preferably, the first metallocene polyethylene is AT6410 produced by Dow Chemical Company; the EAA is a solid TM AE; the brand of low-density polyethylene is 2420H produced by Yangba Petrochemical Company; the brand of the first high-density polyethylene is AT6900 produced by Dow Company; the brand of the second high-density polyethylene is HD3355F produced by Thailand PTT Company; the brand of metallocene linear low-density polyethylene is 2012MA produced by Exxon Company; the brand of linear polyethylene is F182 produced by Yangzi Petrochemical Company; the brand of the second metallocene polyethylene is KS340T produced by JPE Company; the brand of lubricant is 10090-K produced by Anse Color Company; the brand of anti-blocking agent is AB-20LD produced by Beijing Aaron Company; the brand of silicone masterbatch is MBSI-002P produced by Dow Corning Company.

[0012] Preferably, the MDOPE layer is made by gravure printing of an MDOPE film.

[0013] Preferably, the total thickness of the packaging film is 130 μm.

[0014] To achieve the second purpose above, the present invention provides a process for preparing an ultra-low temperature recyclable liquid-washable small packaging film, comprising the following steps:

[0015] S1, weighing each raw material particle of the high barrier VMPE layer for film blowing processing, and then performing vacuum aluminum plating on the first corona layer after the processing to obtain a high barrier VMPE layer;

[0016] S2, weighing each raw material particle of the ultra-low temperature PE layer and performing film blowing processing to obtain an ultra-low temperature PE layer;

[0017] S3, preparing an MDOPE (uniaxially oriented PE) film by gravure printing to obtain an MDOPE layer; then dry-compounding the MDOPE layer with the high barrier VMPE layer, and then aging and cooling the composite layer in sequence to obtain an MDOPE / VMPE composite layer;

[0018] S4, subjecting the MDOPE / VMPE composite layer and the ultra-low temperature PE layer to an online corona composite process and aging in sequence to obtain a packaging film.

[0019] Preferably, in step S1 and step S2, high-voltage online corona treatment is performed during the film blowing process to achieve a surface OD value of 38 or above; in step S1, the OD value (optical density) of the first corona layer after vacuum aluminum plating is 2.5.

[0020] Preferably, in step S3, the glue used for dry compounding is Gaomeng adhesive, which is prepared from a first main agent, a first curing agent and ethyl ester in a mass ratio of 20:3:30. The brand of the first main agent is EA6128A, and the brand of the first curing agent is EA6128B. After compounding, it is placed in a aging chamber with a temperature of 50 degrees. After being placed in the aging chamber for 24 hours, it is pulled out and cooled for 24 hours before a second compounding is performed. The second compounding is the corona online compounding in step S4.

[0021] In step S4, before compounding, the corona machine is turned on and the corona machine current is set to 9.8 kvA. The MDOPE / VMPE composite layer obtained in step S3 is first coronaed and then coated with glue, and laminated with the ultra-low temperature PE layer in an oven. After compounding, it is placed in a 50-degree aging chamber for aging for 36 hours; the glue for coating is prepared by a second main agent, a second curing agent and ethyl ester in a mass ratio of 20:4:32, the brand of the second main agent is Huateng UK2866A, and the brand of the second curing agent is Huateng 2866.

[0022] The advantages of the present invention are:

[0023] (1) The packaging film prepared by the present invention has a low sealing temperature, which meets the requirements of high-speed packaging equipment, has high barrier properties to water vapor, and can reduce the loss of water in small liquid-washed packages. The material from the outer layer to the middle layer to the inner layer is PE material. The entire film is composed of a single PE material and can be recycled for further processing after use, which greatly reduces pollution to the environment.

[0024] (2) Compared with the original small liquid-washing packaging, the composite film of the present invention has better moisture barrier properties, can reduce water loss during the shelf life, and can ensure the quality of the liquid-washing substances in the packaging for a long time; because the inner layer is low-temperature PE, the entire film has a wider heat-sealing window, good machine adaptability, good tearing effect, and is more convenient for customers to use. Moreover, the entire roll film is composed of PE resin, which is a single PE material. Compared with the original polyester and polyolefin composite packaging, the used film can be further recycled and processed for use.

[0025] (3) In the high barrier VMPE layer of the present invention, the first corona layer: using the first metallocene polyethylene and EAA, can improve the adhesion of the aluminum layer after aluminum plating, the bonding strength of the aluminum layer is higher, the surface tension decays slowly, and the bonding strength of the aluminum layer can be maintained more permanently. The peel strength after compounding is more durable and stable, without delamination, and the probability of aluminum layer transfer after compounding is reduced;

[0026] First middle layer: Add the first high-density polyethylene, whose density is 0.969g / cm 3, can provide excellent moisture barrier effect for packaging film, greatly improve the overall moisture barrier performance of packaging film, and at the same time improve the overall film stiffness, online packaging machine adaptability is better, with a certain proportion of low-density polyethylene, so that the overall processability is better, the film surface is smoother, and the overall thickness is more uniform;

[0027] Inner layer: adding 70wt% of the second high-density polyethylene can improve the overall density and stiffness of the packaging film, as well as the water-blocking effect. Adding a certain amount of metallocene linear low-density polyethylene can improve the peel strength of the composite packaging film.

[0028] (4) In the ultra-low temperature PE layer of the present invention, the second corona layer uses a linear polyethylene with a grade of F182, which does not contain a lubricant or an opening agent, so that the film composite has a higher fastness and is not easy to delaminate;

[0029] Adding the second high-density polyethylene with the grade of HD3355F to the second intermediate layer can improve the density of the film and the overall moisture barrier and stiffness of the composite film, making it more adaptable to online packaging machines. A certain proportion of low-density polyethylene can make the overall processability better.

[0030] Inner layer: 30wt% of the second metallocene polyethylene with the brand name KS340T is added, and its melting point is 60 degrees, which can provide a lower heat sealing temperature. Since the outer surface of the packaging film is an MDOPE layer with poor heat resistance, it is easy to be scalded and wrinkled if high-temperature processing is adopted. Therefore, the inner layer of the packaging film of the present invention adopts an ultra-low temperature PE layer, which can provide a wider heat sealing processing window. The metallocene linear low-density polyethylene with the brand name 2012MA and the low-density polyethylene with the brand name 2420H are matched, so that the sealing temperature of the inner layer (ultra-low temperature PE layer) of the packaging film is 80-85 degrees, and the overall sealing can be completely completed at 125 degrees, with better sealing and better mechanical properties; the opening agent with the brand name AB-20LD and the silicone masterbatch with the brand name MBSI-002P are added to improve the opening of the packaging film and reduce the occurrence of adhesion of the packaging film. The lubricant with the brand name 10090-K can reduce the friction coefficient of the film, so that the packaging film can run more smoothly on the packaging machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0032] Example 1

[0033] The invention discloses an ultra-low temperature recyclable liquid-washable small packaging film, which comprises an MDOPE layer, a high barrier VMPE layer and an ultra-low temperature PE layer connected in sequence.

[0034] The high barrier VMPE layer is composed of a first corona layer, a first intermediate layer and an inner layer connected in sequence; the first corona layer includes 65 parts by mass of a first metallocene polyethylene, 20 parts by mass of EAA (ethylene acrylic acid copolymer) and 15 parts by mass of low-density polyethylene; the first intermediate layer includes 65 parts by mass of a first high-density polyethylene and 35 parts by mass of low-density polyethylene; the inner layer includes 65 parts by mass of a second high-density polyethylene, 25 parts by mass of a metallocene linear low-density polyethylene and 10 parts by mass of a low-density polyethylene.

[0035] The ultra-low temperature PE layer is composed of a second corona layer, a second intermediate layer and a heat-sealing layer connected in sequence; the first corona layer is connected to the MDOPE layer after an aluminum plating process, and the inner layer is connected to the second corona layer. The second corona layer includes 70 parts by mass of linear polyethylene and 30 parts by mass of low-density polyethylene, the second intermediate layer includes 55 parts by mass of the second high-density polyethylene and 45 parts by mass of low-density polyethylene, and the heat-sealing layer includes 25 parts by mass of the second metallocene polyethylene, 30 parts by mass of metallocene linear low-density polyethylene, 40 parts by mass of low-density polyethylene, 2 parts by mass of a lubricant, 1 part by mass of an anti-blocking agent and 2 parts by mass of a silicone masterbatch.

[0036] like Figure 1 As shown, a preparation process of an ultra-low temperature recyclable liquid-washable small packaging film comprises the following steps:

[0037] S1. The high barrier VMPE layer is processed by film blowing according to the above formula. During the film blowing process, high voltage online corona treatment is performed to make the surface OD value reach above 38. After the film blowing process, high vacuum aluminum plating treatment is performed to plate aluminum on the first corona layer to make its OD value reach 2.5.

[0038] S2, ultra-low temperature PE layer, is blown according to the above formula, and high-voltage online corona treatment is performed during the film blowing process to make its surface DYN value reach above 38;

[0039] S3, the MDOPE layer is made by gravure printing of the MDOPE film and then dry-compounding it with the high-barrier VMPE layer. The glue is made of Gaomeng adhesive, and the glue ratio is main agent (EA6128A): curing agent (EA6128B): ethyl ester = 20:3:30. After the compounding, it is put into a 50-degree aging room for 24 hours, and then cooled for 24 hours to obtain the MDOPE / VMPE composite layer;

[0040] S4, the second lamination is corona online lamination. Before lamination, the corona machine is turned on and the current of the corona machine is set to 9.8kvA. The MDOPE / VMPE composite layer prepared in step S3 is first corona treated and then coated with glue. The composite layer is laminated with the ultra-low temperature PE layer in an oven. The ratio of the glue coated is main agent (Hua Teng UK2866A): curing agent (Hua Teng 2866): ethyl ester = 20:4:32. After lamination, the film is placed in a 50-degree aging chamber for 36 hours to obtain a packaging film.

[0041] Example 2

[0042] The packaging film and preparation method thereof of this embodiment are different from those of Embodiment 1 in the formula of the high barrier VMPE layer and the formula of the ultra-low temperature PE layer, and the rest are the same as those of Embodiment 1.

[0043] The formulas of the high barrier VMPE layer and the ultra-low temperature PE layer of the packaging film of this embodiment are respectively:

[0044] In the high barrier VMPE layer, the first corona layer includes 70 parts by mass of the first metallocene polyethylene, 15 parts by mass of EAA and 15 parts by mass of low-density polyethylene; the first intermediate layer includes 70 parts by mass of the first high-density polyethylene and 30 parts by mass of low-density polyethylene; the inner layer includes 70 parts by mass of the second high-density polyethylene, 20 parts by mass of metallocene linear low-density polyethylene and 10 parts by mass of low-density polyethylene;

[0045] In the ultra-low temperature PE layer, the second corona layer includes 75 parts by mass of linear polyethylene and 25 parts by mass of low-density polyethylene, the second intermediate layer includes 60 parts by mass of second high-density polyethylene and 40 parts by mass of low-density polyethylene, and the heat-sealing layer includes 30 parts by mass of second metallocene polyethylene, 30 parts by mass of metallocene linear low-density polyethylene, 34 parts by mass of low-density polyethylene, 2.5 parts by mass of lubricant, 1 part by mass of opening agent and 2.5 parts by mass of silicone masterbatch.

[0046] Example 3

[0047] The packaging film and preparation method thereof of this embodiment are different from those of Embodiment 1 in the formula of the high barrier VMPE layer and the formula of the ultra-low temperature PE layer, and the rest are the same as those of Embodiment 1.

[0048] The formulas of the high barrier VMPE layer and the ultra-low temperature PE layer of the packaging film of this embodiment are respectively:

[0049] In the high barrier VMPE layer, the first corona layer includes 75 parts by mass of a first metallocene polyethylene, 10 parts by mass of EAA and 15 parts by mass of a low-density polyethylene; the first intermediate layer includes 75 parts by mass of a first high-density polyethylene and 25 parts by mass of a low-density polyethylene; the inner layer includes 75 parts by mass of a second high-density polyethylene, 15 parts by mass of a metallocene linear low-density polyethylene and 10 parts by mass of a low-density polyethylene.

[0050] In the ultra-low temperature PE layer, the second corona layer includes 80 parts by mass of linear polyethylene and 20 parts by mass of low-density polyethylene, the second intermediate layer includes 65 parts by mass of second high-density polyethylene and 35 parts by mass of low-density polyethylene, and the heat-sealing layer includes 35 parts by mass of second metallocene polyethylene, 25 parts by mass of metallocene linear low-density polyethylene, 32.5 parts by mass of low-density polyethylene, 3 parts by mass of lubricant, 1.5 parts by mass of opening agent and 3 parts by mass of silicone masterbatch.

[0051] The grades of the particles in Examples 1 to 3 are: the grade of the first metallocene polyethylene is AT6410 produced by Dow; the grade of EAA is the grade of the solid polyethylene produced by Dow; TM AE; the brand of low-density polyethylene is 2420H produced by Yangba Petrochemical Company; the brand of the first high-density polyethylene is AT6900 produced by Dow Company; the brand of the second high-density polyethylene is HD3355F produced by Thailand PTT Company; the brand of metallocene linear low-density polyethylene is 2012MA produced by Exxon Company; the brand of linear polyethylene is F182 produced by Yangzi Petrochemical Company; the brand of the second metallocene polyethylene is KS340T produced by JPE Company; the brand of lubricant is 10090-K produced by Anse Color Company; the brand of anti-blocking agent is AB-20LD produced by Beijing Aaron Company; the brand of silicone masterbatch is MBSI-002P produced by Dow Corning Company.

[0052] Comparative Example 1

[0053] PET / PE / VMPET / PE composite film.

[0054] Comparative Example 2

[0055] PET / VMPET / PE composite film.

[0056] The packaging film prepared in Example 2 was subjected to performance tests, as shown in Table 1 below:

[0057]

[0058] As shown in Table 1, the packaging film prepared by the present invention has a moisture resistance value (WVTR) <0.2g / (㎡·24h) and an oxygen resistance value (OTR) <10cm 3 / (㎡·24h·0.1MPa), the sealing temperature is 85℃, and the heat sealing strength is ≧25N / 15mm. Compared with Comparative Examples 1 and 2, it is shown that the packaging film prepared by the present invention has high barrier properties, low sealing temperature, and high heat sealing strength.

[0059] The packaging film of the present invention is made of PE material from the outer layer to the middle layer to the inner layer. The entire film is composed of a single PE material, which is convenient for recycling and reuse to continue to create value.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultra-low temperature recyclable liquid-washable small packaging film, characterized in that: The packaging film comprises an MDOPE layer, a high-barrier VMPE layer and an ultra-low-temperature PE layer which are connected in sequence, wherein the high-barrier VMPE layer is composed of a first corona layer, a first intermediate layer and an inner layer which are connected in sequence; the ultra-low-temperature PE layer is composed of a second corona layer, a second intermediate layer and a heat-sealing layer which are connected in sequence; the first corona layer is connected to the MDOPE layer after an aluminum plating process, and the inner layer is connected to the second corona layer.

2. The ultra-low temperature recyclable liquid-washable small packaging film according to claim 1, characterized in that: The first corona layer comprises 65-75 parts by mass of a first metallocene polyethylene, 10-20 parts by mass of EAA and 10-20 parts by mass of a low-density polyethylene; the first intermediate layer comprises 65-75 parts by mass of a first high-density polyethylene and 25-35 parts by mass of a low-density polyethylene; the inner layer comprises 65-75 parts by mass of a second high-density polyethylene, 15-25 parts by mass of a metallocene linear low-density polyethylene and 5-15 parts by mass of a low-density polyethylene; the second corona layer comprises 70-80 parts by mass of a linear polyethylene and 20-30 parts by mass of a low-density polyethylene, the second intermediate layer comprises 55-65 parts by mass of a second high-density polyethylene and 35-45 parts by mass of a low-density polyethylene, and the heat-sealing layer comprises 25-35 parts by mass of a second metallocene polyethylene, 25-35 parts by mass of a metallocene linear low-density polyethylene, 30-40 parts by mass of a low-density polyethylene, 2-3 parts by mass of a lubricant, 0.5-1.5 parts by mass of an opening agent and 2-3 parts by mass of a silicone masterbatch.

3. The ultra-low temperature recyclable liquid-washable small packaging film according to claim 2, characterized in that: The first corona layer comprises 70 parts by mass of a first metallocene polyethylene, 15 parts by mass of EAA and 15 parts by mass of a low-density polyethylene; the first intermediate layer comprises 70 parts by mass of a first high-density polyethylene and 30 parts by mass of a low-density polyethylene; the inner layer comprises 70 parts by mass of a second high-density polyethylene, 20 parts by mass of a metallocene linear low-density polyethylene and 10 parts by mass of a low-density polyethylene; the second corona layer comprises 75 parts by mass of a linear polyethylene and 25 parts by mass of a low-density polyethylene, the second intermediate layer comprises 60 parts by mass of a second high-density polyethylene and 40 parts by mass of a low-density polyethylene, and the heat-sealing layer comprises 30 parts by mass of a second metallocene polyethylene, 30 parts by mass of a metallocene linear low-density polyethylene, 34 parts by mass of a low-density polyethylene, 2.5 parts by mass of a lubricant, 1 part by mass of an opening agent and 2.5 parts by mass of a silicone masterbatch.

4. The ultra-low temperature recyclable liquid-washable small packaging film according to claim 1, characterized in that: The thickness ratio of the first corona layer, the first intermediate layer and the inner layer is 1:2:1; the thickness ratio of the second corona layer, the second intermediate layer and the heat sealing layer is 1:2:1; the thickness ratio of the MDOPE layer, the high barrier VMPE layer and the ultra-low temperature PE layer is 5:9:

12.

5. The ultra-low temperature recyclable liquid-washable small packaging film according to claim 2 or 3, characterized in that: The brand of the first metallocene polyethylene is AT6410 produced by Dow; the brand of EAA is the reliable Q AE; the brand of low-density polyethylene is 2420H produced by Yangba Petrochemical Company; the brand of the first high-density polyethylene is AT6900 produced by Dow Company; the brand of the second high-density polyethylene is HD3355F produced by Thailand PTT Company; the brand of metallocene linear low-density polyethylene is 2012MA produced by Exxon Company; the brand of linear polyethylene is F182 produced by Yangzi Petrochemical Company; the brand of the second metallocene polyethylene is KS340T produced by JPE Company; the brand of lubricant is 10090-K produced by Anse Color Company; the brand of anti-blocking agent is AB-20LD produced by Beijing Aaron Company; the brand of silicone masterbatch is MBSI-002P produced by Dow Corning Company.

6. The ultra-low temperature recyclable liquid-washable small packaging film according to claim 1, characterized in that: The MDOPE layer is prepared by gravure printing of an MDOPE film.

7. The ultra-low temperature recyclable liquid-washable small packaging film according to claim 1, characterized in that: The total thickness of the packaging film was 130 μm.

8. A process for preparing the ultra-low temperature recyclable liquid-washable small packaging film according to any one of claims 1 to 7, characterized in that: The steps include: S1, weighing each raw material particle of the high barrier VMPE layer for film blowing processing, and then performing vacuum aluminum plating on the first corona layer after the processing to obtain a high barrier VMPE layer; S2, weighing each raw material particle of the ultra-low temperature PE layer and performing film blowing processing to obtain an ultra-low temperature PE layer; S3, preparing an MDOPE layer by gravure printing the MDOPE film; then dry-compounding the MDOPE layer with the high-barrier VMPE layer, and then aging and cooling the composite layer in sequence to obtain an MDOPE / VMPE composite layer; S4, subjecting the MDOPE / VMPE composite layer and the ultra-low temperature PE layer to an online corona composite process and aging in sequence to obtain a packaging film.

9. The process for preparing the ultra-low temperature recyclable liquid-washable small packaging film according to claim 8, characterized in that: In step S1 and step S2, high-voltage online corona treatment is performed during the film blowing process to make the surface OD value reach above 38; in step S1, the OD value of the first corona layer after vacuum aluminum plating treatment is 2.

5.

10. The process for preparing the ultra-low temperature recyclable liquid-washable small packaging film according to claim 8, characterized in that: In step S3, the glue used in the dry compounding is Gaomeng adhesive, which is prepared from a first main agent, a first curing agent and ethyl ester in a mass ratio of 20:3:30; in step S4, the glue used in the corona online compounding process is prepared from a second main agent, a second curing agent and ethyl ester in a mass ratio of 20:4:32.

Images