A drop-resistant recyclable MDOPE sterile packaging bag and its preparation method

Abstract

The present invention belongs to the technical field of packaging materials, specifically relating to a drop-resistant, recyclable MDOPE sterile packaging bag and its preparation method. The bag is composed of a composite of an MDOPE film, a VMBOPE film, and a PE film. The MDOPE film is co-extruded from an inner layer, a middle layer, and an outer layer connected in sequence; the PE film is co-extruded from a first layer, a second layer, and a third layer; and the VMBOPE film is made from a BOPE film subjected to a vacuum aluminum plating process. The resulting packaging bag exhibits excellent drop resistance and antibacterial properties. Furthermore, the sterile packaging bag utilizes a single film material during its preparation, facilitating waste recycling and reuse, which is environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, and in particular to a drop-resistant and recyclable MDOPE sterile packaging bag and a preparation method thereof. Background Art

[0002] Flexible packaging bags are made by sealing the film on each side of the bag to form a cavity for the contents. Compared to rigid containers, they offer advantages such as light weight, compactness, and portability. They are currently widely used in industries such as food, daily chemicals, pharmaceuticals, and hazardous materials. The primary raw material for flexible packaging bags is plastic film. Plastic film can be divided into single film and composite film. Single film is made by hot-melt extrusion of masterbatch pellets through an extruder, followed by casting, calendering, or blow molding, and sometimes also uniaxial or biaxial stretching. Single film has limited and single functions, and often cannot provide both water and gas barrier properties. Therefore, most flexible packaging bags on the market are made from composite film. Composite film is produced by coating, hot-melt extrusion, vacuum coating, or adhesive lamination of single film. It possesses both good barrier properties and good mechanical properties, capable of withstanding a certain degree of impact from the contents. Polyethylene is currently the most important general-purpose plastic and the most widely produced and applied polymer material among synthetic resins. Polyethylene can be processed using general thermoplastic molding methods. It is odorless, non-toxic, feels like wax, has excellent low-temperature resistance, good chemical stability, can withstand the erosion of most acids and alkalis, is insoluble in general solvents at room temperature, has low water absorption, and is widely used in industry, agriculture, and daily necessities. Among them, it is most widely used in packaging materials.

[0003] Chinese patent publication number CN118386631A discloses a pure PE liquid self-supporting bag with high oxygen barrier properties, wherein the outer layer of the self-supporting bag is a uniaxially oriented PE film (MDOPE film), and the inner layer of the self-supporting bag is a 7-layer co-extruded high oxygen barrier PE film, whose specific structure is PE1 / PE2 / TIE3 / EVOH / TIE3 / PE2 / PE1; the physical blending of ethylene-vinyl alcohol copolymer resin and maleic anhydride grafted polyethylene promotes the compatibility of ethylene-vinyl alcohol copolymer and base PE resin, making the distribution of ethylene-vinyl alcohol copolymer in the film layer more uniform and uniform, thereby obtaining a PE film with high oxygen barrier properties; Chinese patent publication number CN118772490A discloses an antibacterial packaging bag and a preparation method thereof, which creatively sets the positional relationship between the antibacterial outer layer and the shielding inner layer, as well as specific fillers, and a layered composite structure between the antibacterial outer layer and the shielding inner layer; the design of the structure and the selection of raw materials enable the prepared packaging bag to have good antibacterial function and UV resistance, and the preparation process is simple to operate and easy to industrialize. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a drop-resistant and recyclable MDOPE sterile packaging bag and a preparation method thereof. The bag is compounded in sequence by MDOPE film, VMBOPE film and PE film. The prepared packaging bag has good drop resistance and antibacterial properties.

[0005] The technical solutions provided by the present invention for solving the above technical problems are as follows:

[0006] A drop-resistant and recyclable MDOPE sterile packaging bag, wherein the sterile packaging bag is formed by sequentially compounding an MDOPE film, a VMBOPE film, and a PE film;

[0007] The MDOPE film includes an inner layer, a middle layer and an outer layer connected in sequence; the inner layer includes 55-65 parts by weight of ultra-low molecular weight polyethylene, 35-45 parts by weight of ultra-high molecular weight polyethylene and 0.2-0.4 parts by weight of a processing aid; the middle layer includes 25-35 parts by weight of ultra-low molecular weight polyethylene, 45-55 parts by weight of ultra-high molecular weight polyethylene, 20-30 parts by weight of metallocene polyethylene and 0.3-0.5 parts by weight of a processing aid; the outer layer includes 30-40 parts by weight of ultra-high molecular weight polyethylene, 55-65 parts by weight of metallocene polyethylene and 0.3-0.5 parts by weight of a processing aid; the MDOPE film is a uniaxially stretched PE film; the processing aid is 100991-K produced by Anpise Company.

[0008] Flexible plastic packaging is a common form of packaging, primarily including polyethylene film, polypropylene film, polyester film, polycarbonate film, and polyimide film. Polyethylene is currently the most important general-purpose plastic and the most widely used polymer material in terms of production volume among synthetic resins. It is formed through the addition polymerization of ethylene. Polyethylene also includes copolymers of ethylene and a small amount of α-olefins, which can be processed using conventional thermoplastic molding methods and are widely used as packaging materials. However, during distribution, factors such as handling and falls from heights can easily cause packaging bags to rupture, leading to product loss. Therefore, in the present invention, MDOPE film, VMBOPE film, and PE film are sequentially compounded to obtain packaging bags with superior performance. The MDOPE film, located on the outer layer of the packaging bag, needs to possess excellent toughness, strength, and impact resistance, providing a certain level of protection in the event of an accidental drop, preventing rupture and protecting the packaged product. Therefore, in the present invention, the MDOPE film is coextruded from an inner layer, a middle layer, and an outer layer that are sequentially connected. The inner layer primarily consists of ultra-low molecular weight polyethylene (ULMPE) and ultra-high molecular weight polyethylene (UHMWPE); the middle layer primarily comprises ultra-low molecular weight polyethylene (ULMPE), ultra-high molecular weight polyethylene (UHMWPE), and metallocene polyethylene (MPE); and the outer layer primarily comprises ultra-high molecular weight polyethylene (UHMWPE) and metallocene polyethylene (MPE). ULMPE, a copolymer of ethylene and polar monomers, exhibits high rigidity and toughness, good mechanical strength, and resistance to environmental stress cracking, while also possessing good flexibility. UHMWPE has a long, intertwined main chain with a crystallinity of 65%-85%, exhibiting outstanding wear resistance, excellent stress cracking resistance, high-temperature creep resistance, low-temperature resistance, excellent tensile strength, and extremely high impact strength. MPE has a wide molecular weight and composition distribution, resulting in a lower heat-sealing initiation temperature than traditional polyethylene, excellent low-temperature heat-sealing properties, and high heat-sealing strength. At the same time, in order to make the layers of the MDOPE film more compatible, the raw materials of the inner layer and the middle layer of the present invention contain the same raw material components of ultra-low molecular weight polyethylene and ultra-high molecular weight polyethylene, and the raw materials of the middle layer and the outer layer contain ultra-high molecular weight polyethylene and metallocene polyethylene; the layers in contact with each other have some of the same raw materials, so during the co-extrusion process, the repulsion between the layers caused by the large difference in raw materials can be reduced, so that the layers are more tightly compounded.

[0009] The VMBOPE film is made from BOPE film through a vacuum aluminum plating process. The BOPE film has high molecular weight and crystal orientation, excellent impact and puncture resistance, and minimal deformation after impact, significantly reducing package breakage during transportation and display. Furthermore, by vacuum aluminum plating on both sides of the BOPE film, a double-aluminum-plated BOPE film is obtained, which combines the properties of both film and metal. After aluminum plating, the film can effectively block light and ultraviolet rays, protecting the contents from damage by light and ultraviolet rays and extending the shelf life. Furthermore, the aluminum layer has excellent electrical conductivity, can eliminate static electricity, and has good sealing performance, ensuring the sealing performance of the packaging.

[0010] The PE film is co-extruded from a first layer, a second layer, and a third layer; the third layer and the inner layer are connected to two sides of the VMBOPE film respectively; the surfaces of the third layer and the inner layer at the connection with the VMBOPE film are both hydroxylated; and the surface of the first layer away from the second layer is grafted with chitosan.

[0011] Furthermore, the first layer comprises 55-65 parts by weight of linear low-density polyethylene and 25-35 parts by weight of high-density polyethylene; the second layer comprises 15-25 parts by weight of linear low-density polyethylene, 55-65 parts by weight of high-density polyethylene and 20-30 parts by weight of ultra-low molecular weight polyethylene; and the third layer comprises 25-35 parts by weight of high-density polyethylene and 55-65 parts by weight of ultra-low molecular weight polyethylene.

[0012] The inner layer of the packaging bag is made of a PE film, which is composited with a first, second, and third layer. The first layer primarily comprises linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE), the second layer primarily comprises linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and ultra-low molecular weight polyethylene (ULMWPE), and the third layer primarily comprises high-density polyethylene (HDPE) and ultra-low molecular weight polyethylene (ULMWPE). LLDPE is a copolymer of ethylene and α-olefins. Due to the introduction of α-olefins, its molecular chain contains numerous short, regular branches, resulting in a crystallinity intermediate between that of HDPE and LDPE, making it suitable for film production and possessing higher strength and toughness than LDPE. HDPE exhibits excellent heat and cold resistance, good chemical stability, and high rigidity and toughness, but lacks flexibility. Therefore, during the PE film production process, the second layer, which contains a higher proportion of HDPE, serves as the middle layer of the PE film. Because the first and third layers are composed of highly flexible LLDPE and UMWPE, the films on both sides exhibit increased flexibility during the composite process, providing a protective and buffering effect for the more rigid second layer, resulting in a PE film with both flexibility and rigidity. Similarly, in the process of preparing PE film, the first layer and the second layer as well as the second layer and the third layer contain the same raw material components, that is, the layers in contact with each other have some of the same raw materials. During the compounding process, the large repulsive force caused by the large difference in raw materials can be reduced, making the compounding between layers more compact.

[0013] The present invention also provides a method for preparing a drop-resistant and recyclable MDOPE sterile packaging bag, comprising the following steps:

[0014] S1. Preparation of MDOPE film: Raw materials were weighed and mixed according to the recipe to prepare an inner layer mixture, a middle layer mixture, and an outer layer mixture, respectively. Each layer mixture was added to the corresponding extruder hopper, heated at high temperature to plasticize into a melt, and extruded from the extruder die by three-layer coextrusion to obtain an MDOPE film; wherein the extrusion speed of the extruder was 450±50 kg / h, and the heating temperature of the die was 195-205°C;

[0015] S2. The surface of the inner layer connected to the VMBOPE film is hydroxylated and modified: 1-hydroxycyclohexyl phenyl ketone is dissolved in ethanol, ultrasonically dissolved, and then 1,2,3-butanetriol is added. The mixture is evenly mixed and coated on the surface of the inner layer connected to the VMBOPE film, covered with a glass plate, and irradiated with a UV lamp. After drying, a hydroxylated inner layer is obtained; wherein the UV lamp irradiation conditions are: temperature 45-50° C., sample distance 15-18 cm from the light source, and illumination time 8-10 min; the mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol, and 1,2,3-butanetriol is 0.1-0.25:10:2-4.5;

[0016] In this step, free radicals are generated under heating conditions by the free radical photoinitiator 1-hydroxycyclohexyl phenyl ketone. These free radicals can introduce oxygen-containing functional groups into the surface of the inner layer of the polymer, resulting in the generation of polar functional groups on the surface of the inner layer. 1,2,3-butanetriol is also introduced to give the inner layer surface more polar functional groups, thereby increasing the polarity of the inner layer surface and increasing its bonding strength with the metal.

[0017] S3. Preparation of PE film: Raw materials are weighed and mixed according to the recipe to prepare a first layer mixture, a second layer mixture, and a third layer mixture, respectively. Each layer mixture is added to a corresponding extruder hopper, heated at high temperature to plasticize into a melt, and extruded from the extruder die head by three-layer co-extrusion to obtain a PE film; wherein the extrusion speed of the extruder is 400±50 kg / h, and the heating temperature of the die head is 195-205°C;

[0018] S4. The surface of the third layer connected to the VMBOPE film is hydroxylated and modified: 1-hydroxycyclohexyl phenyl ketone is dissolved in ethanol, ultrasonically dissolved, and then 1,2,3-butanetriol is added. The mixture is evenly mixed and coated on the surface of the third layer connected to the VMBOPE film, covered with a glass plate, and irradiated with a UV lamp. After drying, a hydroxylated third layer is obtained; wherein the UV lamp irradiation conditions are: temperature 45-50° C., sample distance 15-18 cm from the light source, and illumination time 8-10 min; the mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol, and 1,2,3-butanetriol is 0.1-0.25:10:2-4.5;

[0019] The purpose of this step of hydroxylating the surface of the third layer connected to the VMBOPE film is similar to the purpose of step S2 of hydroxylating the surface of the inner layer connected to the VMBOPE film;

[0020] S5. Grafting chitosan on the surface of the first layer away from the second layer: uniformly mix benzophenone and acrylic acid and drop them on the surface of the first layer away from the second layer, cover with a glass plate, irradiate with ultraviolet light, and then place in a vacuum drying oven at 45-55°C for 4-6 hours to obtain an acrylic acid grafted film; treat the acrylic acid grafted film with alkali solution and place in a vacuum drying oven at 50-65°C for 3-5 hours, then apply chitosan acetic acid solution on the surface and air dry naturally to obtain the first layer grafted with chitosan; wherein the conditions for ultraviolet light irradiation are: temperature 40-45°C, sample The light source is 13-15 cm away from the sample, and the illumination time is 6-8 minutes. The mass ratio of benzophenone to acrylic acid is 0.1:6-8.5. The alkali treatment process is as follows: sodium hydroxide solution is applied to the surface of the acrylic acid grafted film for 8-12 minutes, followed by washing with distilled water 3-5 times. The concentration of the sodium hydroxide solution is 0.2 mol / L. The chitosan acetic acid solution is prepared by dissolving chitosan in an acetic acid aqueous solution and stirring uniformly. The volume ratio of acetic acid to water is 1:100, and the mass concentration of chitosan in the acetic acid aqueous solution is 0.5%-1.2%.

[0021] In this step, chitosan, a natural antimicrobial agent, can damage cell walls and membranes, altering the permeability of cell membranes and causing leakage of cell contents, achieving both antibacterial and antimicrobial effects. In this step, acrylic acid is first grafted onto the surface of the first layer to introduce polar groups to improve surface wettability, followed by chitosan coating. The grafted acrylic acid chains contain numerous polar groups, such as carbonyl and hydroxyl groups, which can form hydrogen bonds with the hydroxyl groups of the chitosan molecules, securing the chitosan molecules to the film surface.

[0022] S6. Preparation of VMBOPE film: placing a BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is introduced into the aluminum plating chamber in stages to obtain a single-sided aluminum-plated BOPE film; then placing the single-sided aluminum-plated BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is introduced into the aluminum plating chamber in stages to obtain a double-sided aluminum-plated BOPE film; wherein, during the vacuum aluminum plating process of the aluminum-plated BOPE film, the unwinding speed of the BOPE film is 180-320 m / min, the feeding speed of the aluminum wire is 0.6-1.2 m / min, the temperature in the aluminum plating chamber is 1300±50°C, and the vacuum degree is greater than 2×10 -2 Pa; The BOPE film is subjected to corona treatment before vacuum aluminizing; In this step, the corona treatment before vacuum aluminizing can form a microstructure on the surface of the aluminized film, increase the surface energy, and thus improve the adhesion of the aluminized film;

[0023] S7, compounding the MDOPE film and the VMBOPE film to obtain an MDOPE / VMBOPE composite film;

[0024] S8, compounding the PE film with the MDOPE / VMBOPE composite film to obtain an MDOPE / VMBOPE / PE composite film;

[0025] S9, ripening and bagging the MDOPE / VMBOPE / PE composite film to obtain the aseptic packaging bag.

[0026] During the composite membrane preparation process, the third and inner layers are in contact with the VMBOPE film under pressure. Because the surfaces of the third and inner layers contacting the VMBOPE film have been hydroxylated and contain a high concentration of oxygen-containing functional groups, such as hydroxyl groups, pressure creates coordination bonds between the third and inner layers and the aluminum-plated layers on both sides of the VMBOPE film. This creates a strong bond between the VMBOPE film, the MDOPE film, and the PE film, resulting in strong adhesion between the layers.

[0027] The present invention has the following beneficial effects:

[0028] The sterile packaging bag prepared by the present invention is formed by compounding an MDOPE film, a VMBOPE film and a PE film in sequence. The MDOPE film is formed by co-extruding an inner layer, a middle layer and an outer layer connected in sequence, the PE film is formed by co-extruding a first layer, a second layer and a third layer, and the VMBOPE film is prepared by vacuum aluminizing a BOPE film. In order to make the layers have better compatibility, the adjacent layers contain the same raw material components, which can reduce the large repulsive force caused by the large difference in raw materials during the compounding process, so that the layers are more tightly compounded. In addition, the surfaces of the MDOPE film and the VMBOPE film in contact with the VMBOPE film are both hydroxylated. During the compounding process, the polar functional groups such as hydroxyl groups contained on the surfaces of the MDOPE film and the VMBOPE film form a strong bonding effect with the aluminized layer of the VMBOPE film, thereby enhancing the adhesion between the layers. In addition, chitosan is grafted on the surface of the first layer away from the second layer, so that the prepared packaging bag has good antibacterial properties. At the same time, the aseptic packaging bags prepared by the present invention use homogeneous materials in the preparation process, realizing the single materialization of the film material, facilitating the recycling and reuse of waste materials, and being beneficial to environmental protection. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] The ultra-low molecular weight polyethylene (VL8005) used in the present invention was purchased from Dongguan Hongkuo Plastic Co., Ltd., ultra-high molecular weight polyethylene (code: XW019002884028) was purchased from Sinopharm Chemical Reagent Co., Ltd., and metallocene polyethylene (industrial grade) was purchased from Mitsui Chemicals of Japan; linear low-density polyethylene (DFDA7042) was purchased from China National Petroleum Corporation; high-density polyethylene (BE0400) was purchased from Suzhou Fengjuan Plastic Raw Materials Co., Ltd.; 1-hydroxycyclohexyl phenyl ketone (98%), 1,2,3-butanetriol (TCI-B0918, 90.0% (GC)), dibenzophenone (AR), acrylic acid (AR (Shanghai test), ≥99.0%), and chitosan (SigmaAldrich-448869) were purchased from Sinopharm Chemical Reagent Co., Ltd. All reagents are commercially available.

[0031] Example 1

[0032] A drop-resistant and recyclable MDOPE sterile packaging bag is formed by sequentially compounding an MDOPE film, a VMBOPE film and a PE film.

[0033] The MDOPE film includes an inner layer, a middle layer and an outer layer connected in sequence; the inner layer includes 60 parts by weight of ultra-low molecular weight polyethylene, 40 parts by weight of ultra-high molecular weight polyethylene and 0.3 parts by weight of processing aid; the middle layer includes 30 parts by weight of ultra-low molecular weight polyethylene, 50 parts by weight of ultra-high molecular weight polyethylene, 25 parts by weight of metallocene polyethylene and 0.4 parts by weight of processing aid; the outer layer includes 35 parts by weight of ultra-high molecular weight polyethylene, 60 parts by weight of metallocene polyethylene and 0.4 parts by weight of processing aid; the MDOPE film is a uniaxially stretched PE film; the processing aid is 100991-K produced by Anpise Company.

[0034] The VMBOPE film is made from BOPE film through vacuum aluminum plating process;

[0035] The PE film is co-extruded from the first, second and third layers; the third layer and the inner layer are connected to the two sides of the VMBOPE film respectively; the surfaces of the third layer and the inner layer at the connection with the VMBOPE film are modified by hydroxylation; the surface of the first layer away from the second layer is modified by chitosan grafting.

[0036] The first layer includes 60 parts by weight of linear low-density polyethylene and 30 parts by weight of high-density polyethylene; the second layer includes 20 parts by weight of linear low-density polyethylene, 60 parts by weight of high-density polyethylene and 25 parts by weight of ultra-low molecular weight polyethylene; and the third layer includes 30 parts by weight of high-density polyethylene and 60 parts by weight of ultra-low molecular weight polyethylene.

[0037] A method for preparing a drop-resistant and recyclable MDOPE sterile packaging bag comprises the following steps:

[0038] S1. Preparation of MDOPE film: weigh and mix the raw materials according to the formula to prepare an inner layer mixture, a middle layer mixture and an outer layer mixture respectively, add the mixture of each layer into the corresponding extruder hopper, heat and plasticize it into a melt, and extrude it from the extruder die by three-layer coextrusion to obtain an MDOPE film; wherein the heating temperatures of the eight plasticizing sections are set to 55°C, 190°C, 200°C, 200°C, 200°C, 200°C, 200°C, and 200°C in sequence, the extrusion speed of the extruder is 450±50Kg / h, the heating temperature of the die is 195-205°C, the molten film is inflated to form a film bubble with a blow-up ratio of 2.8, and then cooled at room temperature, and then subjected to MDO longitudinal stretching to obtain the film; the heating temperature for MDO longitudinal stretching is 90°C, and the stretch ratio is 2.6:1; the thickness of the obtained MDOPE film is 30μm;

[0039] S2. The surface of the inner layer connected to the VMBOPE film is hydroxylated and modified: 1-hydroxycyclohexyl phenyl ketone is dissolved in ethanol, ultrasonically dissolved, and then 1,2,3-butanetriol is added. After mixing evenly, it is coated on the surface of the inner layer connected to the VMBOPE film, covered with a glass plate, irradiated with a UV lamp, and then dried to obtain a hydroxylated inner layer; wherein, the UV lamp irradiation conditions are: temperature 45 ° C, sample 16 cm from the light source, and illumination time 10 min; the mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol and 1,2,3-butanetriol is 0.15:10:3.2; the drying conditions are: drying at 45 ° C in a vacuum drying oven for 2.5 h; the grafting rate is: 5.2 g / m 2 The calculation method of grafting rate is: grafting rate = (mass of grafted film (g) - mass of blank film (g)) / grafting area (m 2 ).

[0040] S3, preparation of PE film: raw materials are weighed and mixed according to the formula to prepare a first layer mixture, a second layer mixture and a third layer mixture, respectively, and each layer mixture is added to the corresponding extruder hopper, plasticized into a melt by high-temperature heating, and extruded from the extruder die by three-layer coextrusion to obtain a PE film; wherein the heating temperatures of the 8 plasticizing sections are set to 50°C, 195°C, 200°C, 200°C, 200°C, 200°C, 200°C, and 200°C in sequence, the extrusion speed of the extruder is 400±50Kg / h, the heating temperature of the die head is 195-205°C, the melt is inflated to form a film bubble, the blow-up ratio is 2.2, and then cooled at room temperature; the thickness of the obtained PE film is 28μm;

[0041] S4. The surface of the third layer connected to the VMBOPE film is hydroxylated and modified: 1-hydroxycyclohexyl phenyl ketone is dissolved in ethanol, ultrasonically dissolved, and then 1,2,3-butanetriol is added. After mixing evenly, it is coated on the surface of the third layer connected to the VMBOPE film, covered with a glass plate, irradiated with a UV lamp, and then dried to obtain a hydroxylated modified third layer; wherein, the UV lamp irradiation conditions are: temperature 45°C, sample 16 cm from the light source, and illumination time 10 min; the mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol and 1,2,3-butanetriol is 0.15:10:3.2; the drying conditions are: drying at 45°C in a vacuum drying oven for 2.5 h; the grafting rate is: 4.8 g / m 2 ; The calculation method of the grafting rate is the same as step S2;

[0042] S5. Perform chitosan grafting modification on the surface of the first layer away from the second layer: uniformly mix benzophenone and acrylic acid and drop them on the surface of the first layer away from the second layer, cover with a glass plate, irradiate with ultraviolet light, and then place in a vacuum drying oven at 50°C for 5 hours to obtain an acrylic acid grafted film; treat the acrylic acid grafted film with alkaline solution and place in a vacuum drying oven at 55°C for 4 hours, then apply chitosan acetic acid solution on the surface and air dry naturally to obtain the first layer of chitosan grafting modification; wherein, the conditions for ultraviolet light irradiation are: temperature 45°C, sample distance from light source 100mm, 100mm, 200mm, 300mm, 400mm, 500mm, 800mm, 1000mm, 2000mm, 3000mm, 4000mm, 5000mm, 8000mm, 2000mm, 3000mm, 4000mm, 5 ...6000mm, 7000mm, 80 14 cm, illumination time 8 min; the mass ratio of benzophenone to acrylic acid is 0.1:7.2; the alkali solution treatment process is as follows: sodium hydroxide solution is applied to the surface of the acrylic acid grafted film, and after coating for 10 min, it is washed with distilled water 5 times; the concentration of the sodium hydroxide solution is 0.2 mol / L; the preparation method of chitosan acetic acid solution is as follows: chitosan is dissolved in acetic acid aqueous solution and stirred evenly; the volume ratio of acetic acid to water is 1:100, and the mass concentration of chitosan in acetic acid aqueous solution is 1.0%; the grafting rate is: 7.5 g / m 2 ; The calculation method of the grafting rate is the same as step S2;

[0043] S6. Preparation of VMBOPE film: placing a BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is introduced into the aluminum plating chamber in stages to obtain a single-sided aluminum-plated BOPE film; then placing the single-sided aluminum-plated BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is introduced into the aluminum plating chamber in stages to obtain a double-sided aluminum-plated BOPE film; wherein, during the vacuum aluminum plating process of the aluminum-plated BOPE film, the unwinding speed of the BOPE film is 220 m / min, the feeding speed of the aluminum wire is 0.8 m / min, the temperature in the aluminum plating chamber is 1300±50°C, and the vacuum degree is greater than 2×10 -2 Pa; BOPE film is corona treated before vacuum aluminum plating; the discharge voltage is controlled at 10000V / m 2 ;The thickness of the aluminum coating is 25nm; the thickness of the VMBOPE film is 20μm;

[0044] S7, dry-compositing the MDOPE film and the VMBOPE film at an oven temperature of 50° C. and a composite tension of 6.5 kg to obtain an MDOPE / VMBOPE dry composite film;

[0045] S8, dry-laminating the PE film and the MDOPE / VMBOPE dry composite film at an oven temperature of 55° C. and a composite tension of 6.8 kg to obtain an MDOPE / VMBOPE / PE dry composite film;

[0046] S9. Place the MDOPE / VMBOPE / PE dry composite film in a 45°C oven for 48 hours and then make a sterile packaging bag; the heat sealing temperature is 130°C, the temperature fluctuation is controlled at ±1°C, each position of the bag is heat sealed 4 times, and the bag making speed is controlled at 65 knives / min.

[0047] Example 2

[0048] Compared with the first embodiment, this embodiment has the following differences, specifically:

[0049] In the MDOPE film, the inner layer includes 55 parts by weight of ultra-low molecular weight polyethylene, 35 parts by weight of ultra-high molecular weight polyethylene, and 0.2 parts by weight of a processing aid; the middle layer includes 25 parts by weight of ultra-low molecular weight polyethylene, 45 parts by weight of ultra-high molecular weight polyethylene, 20 parts by weight of metallocene polyethylene, and 0.3 parts by weight of a processing aid; and the outer layer includes 30 parts by weight of ultra-high molecular weight polyethylene, 55 parts by weight of metallocene polyethylene, and 0.3 parts by weight of a processing aid.

[0050] In the PE film, the first layer includes 55 parts by weight of linear low-density polyethylene and 25 parts by weight of high-density polyethylene; the second layer includes 15 parts by weight of linear low-density polyethylene, 55 parts by weight of high-density polyethylene and 20 parts by weight of ultra-low molecular weight polyethylene; and the third layer includes 25 parts by weight of high-density polyethylene and 55 parts by weight of ultra-low molecular weight polyethylene.

[0051] In the preparation process of the sterile packaging bag, in step S1, the blowing ratio is 2.6, the stretching ratio is 2.2:1, and the thickness of the prepared MDOPE film is 26 μm; in step S2, the UV lamp irradiation conditions are: temperature 45°C, sample 15 cm from the light source, and illumination time 8 minutes; the mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol and 1,2,3-butanetriol is 0.1:10:2; the drying conditions are: drying in a vacuum drying oven at 40°C for 2 hours; the grafting rate is: 5.0 g / m 2In step S3, the blowing ratio is 2.0, and the thickness of the PE film is 25 μm. In step S4, the UV irradiation conditions are: temperature 45°C, sample 15 cm from the light source, and illumination time 8 min. The mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol, and 1,2,3-butanetriol is 0.1:10:2. The drying conditions are: drying in a vacuum drying oven at 40°C for 2 h, and the grafting rate is 4.6 g / m 2 In step S5, after ultraviolet light irradiation, the film was placed in a vacuum drying oven at 45°C for 4 hours to obtain an acrylic acid grafted film; the acrylic acid grafted film was treated with alkali solution and dried in a vacuum drying oven at 50°C for 3 hours. The conditions for ultraviolet light irradiation were: temperature 40°C, sample 13 cm from the light source, and illumination time 6 minutes; the mass ratio of benzophenone to acrylic acid was 0.1:6; the alkali solution treatment process was: sodium hydroxide solution was applied to the surface of the acrylic acid grafted film, and after coating for 8 minutes, it was washed with distilled water three times; the mass concentration of chitosan in the acetic acid aqueous solution was 0.5%; the grafting rate was: 7.2 g / m 2 In step S6, the unwinding speed of the BOPE film is 180m / min, the wire feeding speed of the aluminum wire is 0.6m / min, the thickness of the aluminum coating is 20nm, and the discharge voltage is controlled at 9000V / m 2 ; In step S7, the oven temperature is 45°C and the composite tension is 6kg; in step S8, the oven temperature is 50°C and the composite tension is 6.2kg; in step S9, the heat sealing temperature is 120°C, each position of the bag is heat sealed 3 times, and the bag making speed is controlled at 60 knives / min.

[0052] Example 3

[0053] Compared with the first embodiment, this embodiment has the following differences, specifically:

[0054] In the MDOPE film, the inner layer includes 65 parts by weight of ultra-low molecular weight polyethylene, 45 parts by weight of ultra-high molecular weight polyethylene, and 0.4 parts by weight of a processing aid; the middle layer includes 35 parts by weight of ultra-low molecular weight polyethylene, 55 parts by weight of ultra-high molecular weight polyethylene, 30 parts by weight of metallocene polyethylene, and 0.5 parts by weight of a processing aid; and the outer layer includes 40 parts by weight of ultra-high molecular weight polyethylene, 65 parts by weight of metallocene polyethylene, and 0.5 parts by weight of a processing aid.

[0055] In the PE film, the first layer includes 65 parts by weight of linear low-density polyethylene and 35 parts by weight of high-density polyethylene; the second layer includes 25 parts by weight of linear low-density polyethylene, 65 parts by weight of high-density polyethylene and 30 parts by weight of ultra-low molecular weight polyethylene; and the third layer includes 35 parts by weight of high-density polyethylene and 65 parts by weight of ultra-low molecular weight polyethylene.

[0056] In the preparation process of the sterile packaging bag, in step S1, the blowing ratio is 2.9, the stretching ratio is 2.8:1, and the thickness of the prepared MDOPE film is 34 μm; in step S2, the UV lamp irradiation conditions are: temperature 50°C, sample 18 cm from the light source, and illumination time 10 minutes; the mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol and 1,2,3-butanetriol is 0.25:10:4.5; the drying conditions are: drying at 50°C in a vacuum drying oven for 3 hours; the grafting rate is: 4.8 g / m 2 In step S3, the blowing ratio is 2.4, and the thickness of the PE film is 32 μm. In step S4, the UV irradiation conditions are: temperature 50°C, sample distance 18 cm from the light source, and illumination time 10 min. The mass ratio of 1-hydroxycyclohexyl phenyl ketone, ethanol, and 1,2,3-butanetriol is 0.25:10:4.5. The drying conditions are: drying in a vacuum drying oven at 50°C for 3 h, and the grafting rate is 4.3 g / m 2 In step S5, after ultraviolet light irradiation, the film was placed in a vacuum drying oven at 55°C for 6 hours to obtain an acrylic acid grafted film; the acrylic acid grafted film was treated with alkali solution and dried in a vacuum drying oven at 65°C for 5 hours. The conditions for ultraviolet light irradiation were: temperature 45°C, sample 15 cm from the light source, and illumination time 8 minutes; the mass ratio of benzophenone to acrylic acid was 0.1:8.5; the alkali solution treatment process was: sodium hydroxide solution was applied to the surface of the acrylic acid grafted film, and after coating for 12 minutes, it was washed with distilled water 5 times; the mass concentration of chitosan in the acetic acid aqueous solution was 1.2%; the grafting rate was: 7.0 g / m 2 In step S6, the unwinding speed of the BOPE film is 280m / min, the wire feeding speed of the aluminum wire is 1.2m / min, the thickness of the aluminum coating is 28nm, and the discharge voltage is controlled at 9000V / m 2 ; In step S7, the oven temperature is 52°C and the composite tension is 6.8kg; in step S8, the oven temperature is 58°C and the composite tension is 7.2kg; in step S9, the heat sealing temperature is 135°C, each position of the bag is heat sealed 5 times, and the bag making speed is controlled at 70 knives / minute.

[0057] Comparative Example 1

[0058] Compared with Example 1, this comparative example does not perform hydroxylation modification on the surface of the inner layer connected to the VMBOPE film and the surface of the third layer connected to the VMBOPE film, and does not perform chitosan grafting modification on the surface of the first layer away from the second layer. The rest is referenced to Example 1. The specific preparation process is as follows:

[0059] S1. Preparation of MDOPE film: Raw materials are weighed and mixed according to the recipe to prepare an inner layer mixture, a middle layer mixture, and an outer layer mixture, respectively. Each layer mixture is added to a corresponding extruder hopper, plasticized into a melt by high temperature heating, and extruded from the extruder die head by three-layer coextrusion to obtain an MDOPE film;

[0060] S2. Preparation of PE film: weighing and mixing raw materials according to the recipe to prepare a first layer mixture, a second layer mixture, and a third layer mixture respectively, adding each layer mixture into a corresponding extruder hopper, heating at high temperature to plasticize into a melt, and extruding the melt from the extruder die head by three-layer co-extrusion to obtain a PE film;

[0061] S3. Preparation of VMBOPE film: placing the BOPE film in an aluminum plating chamber for vacuum aluminum plating, and filling the aluminum plating chamber with nitrogen in stages after the aluminum plating is completed to obtain a single-sided aluminum-plated BOPE film; then placing the single-sided aluminum-plated BOPE film in an aluminum plating chamber for vacuum aluminum plating, and filling the aluminum plating chamber with nitrogen in stages after the aluminum plating is completed to obtain a double-sided aluminum-plated BOPE film;

[0062] S4, compounding the MDOPE film and the VMBOPE film to obtain an MDOPE / VMBOPE composite film;

[0063] S5, compounding the PE film with the MDOPE / VMBOPE composite film to obtain an MDOPE / VMBOPE / PE composite film;

[0064] S6. The MDOPE / VMBOPE / PE composite film is cured and bag-formed to obtain a sterile packaging bag.

[0065] Comparative Example 2

[0066] Compared with Example 1, this comparative example is to compound the MDOPE film and the VMBOPE film to obtain a sterile packaging bag. The rest is referred to Example 1. The specific preparation process is as follows:

[0067] S1. Preparation of MDOPE film: Raw materials are weighed and mixed according to the recipe to prepare an inner layer mixture, a middle layer mixture, and an outer layer mixture, respectively. Each layer mixture is added to a corresponding extruder hopper, plasticized into a melt by high temperature heating, and extruded from the extruder die head by three-layer coextrusion to obtain an MDOPE film;

[0068] S2. hydroxylation-modifying the surface of the inner layer connected to the VMBOPE film: dissolving 1-hydroxycyclohexyl phenyl ketone in ethanol, ultrasonically dissolving it, adding 1,2,3-butanetriol, mixing them evenly, and coating the surface of the inner layer connected to the VMBOPE film. Covering the surface with a glass plate, irradiating the layer with an ultraviolet lamp, and drying the layer to obtain a hydroxylated inner layer.

[0069] S3. Preparation of VMBOPE film: placing the BOPE film in an aluminum plating chamber for vacuum aluminum plating, and filling the aluminum plating chamber with nitrogen in stages after the aluminum plating is completed to obtain a single-sided aluminum-plated BOPE film; then placing the single-sided aluminum-plated BOPE film in an aluminum plating chamber for vacuum aluminum plating, and filling the aluminum plating chamber with nitrogen in stages after the aluminum plating is completed to obtain a double-sided aluminum-plated BOPE film;

[0070] S4, compounding the MDOPE film and the VMBOPE film to obtain an MDOPE / VMBOPE composite film;

[0071] S5. The MDOPE / VMBOPE composite film is cured and bag-formed to obtain a packaging bag.

[0072] Comparative Example 3

[0073] Compared with Example 1, this comparative example is to compound the PE film and the VMBOPE film to obtain a sterile packaging bag. The rest is referred to Example 1. The specific preparation process is as follows:

[0074] S1. Preparation of PE film: weighing and mixing raw materials according to the recipe to prepare a first layer mixture, a second layer mixture, and a third layer mixture respectively, adding each layer mixture into a corresponding extruder hopper, heating at high temperature to plasticize into a melt, and extruding the PE film from the extruder die head by three-layer co-extrusion;

[0075] S2. hydroxylating the surface of the third layer connected to the VMBOPE film: dissolving 1-hydroxycyclohexyl phenyl ketone in ethanol, ultrasonically dissolving it, adding 1,2,3-butanetriol, mixing them evenly, and coating the mixture on the surface of the third layer connected to the VMBOPE film. Covering the mixture with a glass plate, irradiating the mixture with a UV lamp, and drying the mixture to obtain a hydroxylated third layer.

[0076] S3. Grafting chitosan on the surface of the first layer away from the second layer: uniformly mixing benzophenone and acrylic acid and dropping the mixture onto the surface of the first layer away from the second layer, covering the mixture with a glass plate, irradiating the mixture with a UV lamp, and drying the mixture to obtain an acrylic acid grafted film; treating the acrylic acid grafted film with an alkali solution and drying the film, coating the surface with a chitosan acetic acid solution, and air-drying the mixture to obtain a chitosan grafted modified first layer;

[0077] S4. Preparation of VMBOPE film: placing the BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is injected into the aluminum plating chamber in stages to obtain a single-sided aluminum-plated BOPE film; then placing the single-sided aluminum-plated BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is injected into the aluminum plating chamber in stages to obtain a double-sided aluminum-plated BOPE film;

[0078] S5, compounding the PE film and the VMBOPE film to obtain a PE / VMBOPE composite film;

[0079] S6. The PE / VMBOPE composite film is cured and bag-formed to obtain a sterile packaging bag.

[0080] Related tests:

[0081] The packaging bags prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to relevant tests. A universal tensile testing machine was used to test the tensile strength in the MD and TD directions. The pressure test procedure involved filling the bag with 500g of water, sealing it, and applying an 80kg weight flatly. The pressure test procedure involved maintaining the sealed bag in this state for 60 seconds without breaking or cracking. The drop test procedure involved filling the bag with 500g of water and dropping it six times from a height of 1m without breaking or cracking. The test results are shown in Table 1.

[0082] Table 1 Related performance test results

[0083]

[0084] It can be seen from the above test results that Examples 1 to 3 have good mechanical properties compared with Comparative Examples 1 to 3, and have good pressure resistance and drop resistance, especially Example 1 has the best performance.

[0085] Antibacterial test:

[0086] The packaging bags obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for antibacterial properties in accordance with GB / T 31402-2015 “Test method for antibacterial properties of plastics and plastic surfaces”. The test results are shown in Table 2.

[0087] Table 2 Antibacterial test results

[0088]

[0089] It can be seen from the above test results that Examples 1 to 3 and Comparative Example 3 all have good antibacterial effects, while the packaging bags prepared in Comparative Examples 1 and 2 do not have antibacterial effects because they do not contain grafted chitosan.

[0090] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0091] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A drop-resistant and recyclable MDOPE sterile packaging bag, characterized in that: The aseptic packaging bag is formed by compounding MDOPE film, VMBOPE film and PE film in sequence; The MDOPE film comprises an inner layer, a middle layer and an outer layer connected in sequence; the inner layer comprises 55-65 parts by weight of ultra-low molecular weight polyethylene, 35-45 parts by weight of ultra-high molecular weight polyethylene and 0.2-0.4 parts by weight of a processing aid; the middle layer comprises 25-35 parts by weight of ultra-low molecular weight polyethylene, 45-55 parts by weight of ultra-high molecular weight polyethylene, 20-30 parts by weight of metallocene polyethylene and 0.3-0.5 parts by weight of a processing aid; and the outer layer comprises 30-40 parts by weight of ultra-high molecular weight polyethylene, 55-65 parts by weight of metallocene polyethylene and 0.3-0.5 parts by weight of a processing aid; The VMBOPE film is made of BOPE film through a vacuum aluminum plating process; the PE film is co-extruded by a first layer, a second layer and a third layer; the third layer and the inner layer are respectively connected to the two sides of the VMBOPE film; The surfaces of the third layer and the inner layer at the connection with the VMBOPE film are both hydroxylated and modified. 1-Hydroxycyclohexylphenyl ketone is dissolved in ethanol, ultrasonically dissolved, and then 1,2,3-butanetriol is added. After mixing evenly, the mixture is coated on the surface of the inner layer connected to the VMBOPE film, covered with a glass plate, irradiated with an ultraviolet lamp, and then dried to obtain a hydroxylated inner layer. Free radicals are generated by a free radical photoinitiator, 1-Hydroxycyclohexylphenyl ketone, under heating conditions. These free radicals can introduce oxygen-containing functional groups into the surface of the polymer inner layer, resulting in the generation of polar functional groups on the surface of the inner layer. 1,2,3-butanetriol is also introduced to give the surface of the inner layer more polar functional groups. The surface of the first layer away from the second layer is grafted with chitosan, acrylic acid is grafted on the surface of the first layer, polar groups are introduced on the surface to improve surface wettability, and then chitosan is coated; The first layer comprises 55-65 parts by weight of linear low-density polyethylene and 25-35 parts by weight of high-density polyethylene; the second layer comprises 15-25 parts by weight of linear low-density polyethylene, 55-65 parts by weight of high-density polyethylene and 20-30 parts by weight of ultra-low molecular weight polyethylene; and the third layer comprises 25-35 parts by weight of high-density polyethylene and 55-65 parts by weight of ultra-low molecular weight polyethylene.

2. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 1, characterized in that: The steps include: S1. Preparation of MDOPE film: Raw materials are weighed and mixed according to the recipe to prepare an inner layer mixture, a middle layer mixture, and an outer layer mixture, respectively. Each layer mixture is added to a corresponding extruder hopper, plasticized into a melt by high temperature heating, and extruded from the extruder die head by three-layer coextrusion to obtain an MDOPE film; S2. hydroxylation-modifying the surface of the inner layer connected to the VMBOPE film: dissolving 1-hydroxycyclohexyl phenyl ketone in ethanol, ultrasonically dissolving it, adding 1,2,3-butanetriol, mixing them evenly, and coating the surface of the inner layer connected to the VMBOPE film. Covering the surface with a glass plate, irradiating the layer with an ultraviolet lamp, and drying the layer to obtain a hydroxylated inner layer. S3. Preparation of PE film: weighing and mixing raw materials according to the recipe to prepare a first layer mixture, a second layer mixture, and a third layer mixture respectively, adding each layer mixture into a corresponding extruder hopper, heating at high temperature to plasticize into a melt, and extruding the melt from the extruder die head by three-layer co-extrusion to obtain a PE film; S4. hydroxylating the surface of the third layer connected to the VMBOPE film: dissolving 1-hydroxycyclohexyl phenyl ketone in ethanol, ultrasonically dissolving it, adding 1,2,3-butanetriol, mixing them evenly, and coating the mixture on the surface of the third layer connected to the VMBOPE film. Covering the mixture with a glass plate, irradiating the mixture with an ultraviolet lamp, and drying the mixture to obtain a hydroxylated third layer. S5. Grafting chitosan on the surface of the first layer away from the second layer: uniformly mixing benzophenone and acrylic acid and dropping the mixture onto the surface of the first layer away from the second layer, covering the mixture with a glass plate, irradiating the mixture with a UV lamp, and drying the mixture to obtain an acrylic acid grafted film; treating the acrylic acid grafted film with an alkali solution and drying the film, coating the surface with a chitosan acetic acid solution, and air-drying the mixture to obtain a chitosan grafted modified first layer; S6. Preparation of VMBOPE film: placing the BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is gradually introduced into the aluminum plating chamber to obtain a single-sided aluminum-plated BOPE film; then placing the single-sided aluminum-plated BOPE film in an aluminum plating chamber for vacuum aluminum plating, and after the aluminum plating is completed, nitrogen is gradually introduced into the aluminum plating chamber to obtain a double-sided aluminum-plated BOPE film; S7, compounding the MDOPE film and the VMBOPE film to obtain an MDOPE / VMBOPE composite film; S8, compounding the PE film with the MDOPE / VMBOPE composite film to obtain an MDOPE / VMBOPE / PE composite film; S9, ripening and bagging the MDOPE / VMBOPE / PE composite film to obtain the aseptic packaging bag.

3. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 2, characterized in that: In step S2 and step S4, the conditions for ultraviolet lamp irradiation are: temperature 45-50°C, sample 15-18 cm from the light source, and illumination time 8-10 min; in step S5, the conditions for ultraviolet lamp irradiation are: temperature 40-45°C, sample 13-15 cm from the light source, and illumination time 6-8 min.

4. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 2, characterized in that: In step S5, the alkali solution treatment process is as follows: coating the surface of the acrylic acid grafted membrane with a sodium hydroxide solution for 8-12 minutes, and then washing with distilled water for 3-5 times.

5. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 2, characterized in that: In step S5, the chitosan acetic acid solution is prepared by dissolving chitosan in an acetic acid aqueous solution and stirring the mixture uniformly.

6. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 2, characterized in that: In step S1, the extrusion speed of the extruder is 450±50Kg / h, and the heating temperature of the die head is 195-205°C; in step S3, the extrusion speed of the extruder is 400±50Kg / h, and the heating temperature of the die head is 195-205°C.

7. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 2, characterized in that: In step S6, during the vacuum aluminum plating process of the aluminum-plated BOPE film, the unwinding speed of the BOPE film is 180-320 m / min, the feeding speed of the aluminum wire is 0.6-1.2 m / min, the temperature in the aluminum plating chamber is 1300±50°C, and the vacuum degree is greater than 2×10 -2 Pa.

8. The method for preparing the drop-resistant and recyclable MDOPE sterile packaging bag according to claim 2, characterized in that: In step S6, the BOPE film is subjected to corona treatment before vacuum aluminum plating.

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