PE packaging film and production process thereof

Abstract

The application relates to the field of plastic films, and particularly discloses a PE packaging film and a production process thereof. The PE packaging film comprises the following raw materials in parts by weight: 40-60 parts of low-density polyethylene, 40-60 parts of anti-fog masterbatch, 10-20 parts of an embedded component, and 4-8 parts of nano filler; the embedded component comprises a macromolecular filling resin and an extrusion agent, and the weight ratio of the macromolecular filling resin to the extrusion agent is 40:(1-2); the production process comprises the following steps: uniformly mixing and stirring the low-density polyethylene, the anti-fog masterbatch, the embedded component and the nano filler, extruding and granulating to obtain the masterbatch, and then feeding the masterbatch into a flow casting device to obtain the PE packaging film. The food packaging PE film can be used for food packaging, has the advantages that the anti-fog performance of the packaging film is improved, the environment for the growth and reproduction of microorganisms is reduced, and the corruption and deterioration of fresh food are reduced.

Description

Technical Field

[0001] This application relates to the field of plastic films, and more specifically, to a PE packaging film and its manufacturing process. Background Technology

[0002] Polyethylene (PE) film is the most common and widely used plastic packaging material, and its excellent performance has led to its extensive use in food packaging and agricultural production. Polyethylene itself has high transparency, is easy to process, has a long shelf life, and is inexpensive, resulting in relatively high consumption, accounting for 40% of all plastic packaging.

[0003] At present, the competitive advantage of fresh food in the market mainly depends on the scientific nature and feasibility of its packaging. To a certain extent, food packaging can isolate food from the external environment, prevent microorganisms from entering the food packaging system, and extend the shelf life of fresh food by controlling the relative humidity and regulating the gas composition inside the packaging.

[0004] However, traditional polyethylene packaging films, due to their hydrophobic surface, will fog up during practical applications due to the water vapor produced by the metabolism of fruits and vegetables. The fog not only reduces the transparency of the film, but also accelerates the growth and reproduction of microorganisms, causing fresh food to spoil. Summary of the Invention

[0005] In order to improve the anti-fogging performance of packaging films, thereby reducing the environment for microbial growth and reproduction and reducing the spoilage of fresh food, this application provides a PE packaging film and its production process.

[0006] In a first aspect, this application provides a PE packaging film, which adopts the following technical solution:

[0007] A PE packaging film comprises the following raw materials in parts by weight: 40-60 parts of low-density polyethylene, 40-60 parts of anti-fog masterbatch, 10-20 parts of embedded components, and 4-8 parts of nanofillers. The embedded components include macromolecular filling resin and extruder, and the weight ratio of the macromolecular filling resin and extruder is 40:(1-2).

[0008] By adopting the above technical solution, using low-density polyethylene as the main component and adding anti-fogging masterbatch, the resulting film has anti-fogging properties. The nanofiller improves the dispersion performance of the embedded components. The macromolecular filling resin and extruder in the embedded components enter the interior of the low-density polyethylene to compress the anti-fogging masterbatch, thereby causing the anti-fogging masterbatch to move to the surface. The extruder also causes the anti-fogging components in the anti-fogging masterbatch to be squeezed to the surface. The anti-fogging components reaching the film surface further improve the anti-fogging performance of the polyethylene film, reduce the environment for microbial growth, and reduce the spoilage of fresh food.

[0009] Preferably, the antifogging masterbatch comprises linear low-density polyethylene and an antifogging agent, wherein the weight ratio of the low-density polyethylene and the antifogging agent is 50:(1-3).

[0010] By adopting the above technical solution, the anti-fogging agent and linear low-density polyethylene are combined to generate an anti-fogging masterbatch, which is then combined with low-density polyethylene to prepare a plastic film. The anti-fogging masterbatch is first prepared and then added to low-density polyethylene. The linear low-density polyethylene makes it easier for the anti-fogging agent to be evenly dispersed, thereby further improving the anti-fogging performance.

[0011] Preferably, the antifog masterbatch is prepared by the following steps: mixing and stirring linear low-density polyethylene and an antifog additive, and then extruding and granulating the mixture to obtain the antifog masterbatch.

[0012] By adopting the above technical solution, anti-fogging masterbatch is prepared using internal anti-fogging agent and linear low-density polyethylene as raw materials. Using linear low-density polyethylene as an intermediate component makes it easier for the internal anti-fogging agent and low-density polyethylene to connect and disperse, thereby improving the dispersion degree of the internal anti-fogging agent in the film.

[0013] Preferably, the internal anti-fogging agent is one of xylitol ester, sorbitol monopalmitate, or glyceryl monooleate.

[0014] By adopting the above technical solution, the anti-fogging agent can adapt to the extrusion temperature during the production of anti-fogging masterbatch or polyethylene film, thereby ensuring that the anti-fogging agent exists stably in the anti-fogging masterbatch or polyethylene film, reducing the loss of the anti-fogging agent during the preparation process, and thus making the anti-fogging performance of the anti-fogging masterbatch or polyethylene film more stable.

[0015] Preferably, the extruder comprises polyethylene diamine and sodium stearate, wherein the weight fraction ratio of polyethylene diamine and sodium stearate is 1:(1-3).

[0016] By adopting the above technical solution, using polyethylene diamine and sodium stearate as extruders, after combining polyethylene diamine and sodium stearate with macromolecular filler resin, polyethylene diamine and sodium stearate improve the stability during processing. On the other hand, through amidation, polyethylene diamine and sodium stearate combine, making the groups on the formed compound hydrophobic groups. This causes the hydrophilic groups of the added antifogging agent to face the film surface, thereby further improving the antifogging performance of the film.

[0017] Preferably, the macromolecular filler resin is one of acrylic resin or polyurethane resin.

[0018] By adopting the above technical solution, using acrylic resin or polyurethane resin as the filler resin, since the filler resin is a macromolecular substance, when the filler resin is mixed with low-density polyethylene, the macromolecular substance is easier to remain inside the low-density polyethylene than the added anti-fogging agent, thereby forcing the added anti-fogging agent to move to the film surface, thus allowing the added anti-fogging agent to play a role on the film surface, effectively improving the anti-fogging performance of the polyethylene film.

[0019] Preferably, the embedded component is prepared by the following steps: mixing macromolecular filling resin with polyethylene diamine and sodium stearate, and then extruding and granulating to obtain the embedded component.

[0020] By adopting the above technical solution, the macromolecular filling resin is first mixed with polyethylene diamine and sodium stearate, and then the mixture enters the extrusion granulation stage. During this stage, heating is necessary. During the heating process, polyethylene diamine and sodium stearate react, and amino and carboxyl groups undergo amidation reaction. This results in the formation of a large number of hydrophobic groups in the macromolecular substance. These groups are carried by the macromolecular filling resin inside the polyethylene film, promoting the migration of hydrophilic groups of the added antifogging agent to the surface of the polyethylene film, thereby further improving the antifogging performance of the polyethylene film.

[0021] Preferably, the nanofiller comprises nano-lanthanum oxide and nano-titanium dioxide, wherein the weight ratio of nano-lanthanum oxide to nano-titanium dioxide is 1:(1-3).

[0022] By adopting the above technical solution, using nano-lanthanum oxide and nano-titanium dioxide as fillers, the small particle size, large specific surface area, and high activity of both can effectively improve the dispersion of the added anti-fogging agent. At the same time, the photocatalytic performance of nano-titanium dioxide can also improve the anti-fogging performance of the film.

[0023] Secondly, this application provides a production process for PE packaging film, which adopts the following technical solution: A production process for PE packaging film includes the following steps: mixing and stirring low-density polyethylene, anti-fog masterbatch, embedded components and nanofillers evenly, then extruding and granulating the mixture to obtain masterbatch, and then using casting equipment to produce PE packaging film from the masterbatch.

[0024] By adopting the above technical solution, anti-fog masterbatch, embedded components and nanofillers are mixed with low-density polyethylene to prepare masterbatch, thereby mixing the raw materials and then making the masterbatch into a film, thus effectively improving the processing stability.

[0025] In summary, this application has the following beneficial effects:

[0026] 1. Since this application uses low-density polyethylene as the main component, the addition of anti-fogging masterbatch enables the prepared film to have anti-fogging properties. The nanofiller improves the dispersion performance of the embedded components. The macromolecular filling resin and extruder in the embedded components enter the interior of the low-density polyethylene to compress the anti-fogging masterbatch, thereby causing the anti-fogging masterbatch to move to the surface. The extruder also causes the anti-fogging components in the anti-fogging masterbatch to be squeezed to the surface. The anti-fogging components reaching the film surface further improve the anti-fogging performance of the polyethylene film, reduce the environment for microbial growth, and reduce the spoilage of fresh food.

[0027] 2. In this application, the extruder is first combined with the macromolecular filler resin to prepare an embedded component, so that the extruder and the macromolecular filler resin can more easily remain inside the polyethylene film. Since the macromolecular filler resin and the extruder remain inside the polyethylene film, the added antifogging agent moves to the surface of the polyethylene film, so that the added antifogging agent reaches the surface of the polyethylene film and plays a role, effectively reducing the generation of fog on the surface of the polyethylene film.

[0028] 3. In this application, the extruders are polyethylene diamine and sodium stearate. When these two are used to prepare the embedded components, they enter the screw extruder along with the macromolecular filler resin. Inside the screw extruder, they are inevitably exposed to high temperatures. Under the action of high temperature, these two undergo an amidation reaction, resulting in a large number of hydrophobic groups on the surface of the generated macromolecular material. The hydrophobic groups cause the hydrophilic groups of the added antifogging agent to face the surface of the polyethylene film, thereby further enhancing the antifogging performance of the added antifogging agent and further improving the antifogging ability of the polyethylene film. Detailed Implementation

[0029] In this application, the low-density polyethylene (LDPE) was purchased commercially, in granular form, and its grade is 2426H; the linear low-density polyethylene (LDPE) was purchased commercially, in granular form, and its grade is 7042; the xylitol ester was food-grade xylitol anhydride monostearate, purchased commercially; the sorbitan monopalmitate was purchased commercially; the glyceryl monooleate was purchased commercially; the polyethylene diamine was granular and purchased commercially; the sodium stearate was granular and purchased commercially; the acrylic resin was food-grade ethylene acrylate copolymer, from DuPont, USA, grade 2014; the polyurethane resin was thermoplastic and purchased commercially, and its grade is 1185A10; the nano-lanthanum oxide particles had a diameter of 300 nm and were purchased commercially; and the nano-titanium dioxide particles had a diameter of 100 nm and were purchased commercially.

[0030] The present application will be further described in detail below with reference to the embodiments.

[0031] Example of anti-fogging masterbatch preparation

[0032] Preparation Example 1

[0033] This preparation example provides an anti-fogging masterbatch, which is prepared by the following steps:

[0034] Weigh 50 kg of linear low-density polyethylene and 1 kg of xylitol ester and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical granules are formed, which are the antibacterial masterbatches.

[0035] Preparation Example 2

[0036] This preparation example provides an anti-fogging masterbatch, which is prepared by the following steps:

[0037] Weigh 50 kg of linear low-density polyethylene and 2 kg of xylitol ester and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical granules are formed, which are the antibacterial masterbatches.

[0038] Preparation Example 3

[0039] This preparation example provides an anti-fogging masterbatch, which is prepared by the following steps:

[0040] Weigh 50 kg of linear low-density polyethylene and 3 kg of xylitol ester and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical granules are formed, which are the antibacterial masterbatches.

[0041] Preparation Example 4

[0042] This preparation example provides an anti-fogging masterbatch, which is prepared by the following steps:

[0043] Weigh 50 kg of linear low-density polyethylene and 2 kg of sorbitan monopalmitate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical granules are formed, which are the antibacterial masterbatches.

[0044] Preparation Example 5

[0045] This preparation example provides an anti-fogging masterbatch, which is prepared by the following steps:

[0046] Weigh 50 kg of linear low-density polyethylene and 2 kg of glyceryl monooleate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical granules are formed, which are the antibacterial masterbatches.

[0047] Example of preparation of embedded components

[0048] Preparation Example 6

[0049] This preparation example provides an embedded component, which is prepared by the following steps:

[0050] Weigh 40 kg of acrylic resin, 0.5 kg of polyethylene diamine, and 0.5 kg of sodium stearate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0051] Preparation Example 7

[0052] This preparation example provides an embedded component, which is prepared by the following steps:

[0053] Weigh 40 kg of acrylic resin, 0.5 kg of polyethylene diamine, and 1 kg of sodium stearate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0054] Preparation Example 8

[0055] This preparation example provides an embedded component, which is prepared by the following steps:

[0056] Weigh 40 kg of acrylic resin, 0.5 kg of polyethylene diamine, and 1.5 kg of sodium stearate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0057] Preparation Example 9

[0058] This preparation example provides an embedded component, which is prepared by the following steps:

[0059] Weigh 40 kg of polyurethane resin, 0.5 kg of polyethylene diamine, and 1.5 kg of sodium stearate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0060] Preparation Example 10

[0061] This preparation example provides an embedded component, which is prepared by the following steps:

[0062] Weigh 40 kg of acrylic resin and 1.5 kg of polyethylene diamine and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0063] Preparation Example 11

[0064] This preparation example provides an embedded component, which is prepared by the following steps:

[0065] Weigh 40 kg of acrylic resin and 1.5 kg of sodium stearate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0066] Preparation Example 12

[0067] This preparation example provides an embedded component, which is prepared by the following steps:

[0068] Weigh 40 kg of low-density polyethylene, 0.5 kg of polyethylenediamine, and 1 kg of sodium stearate and add them to a mixer. The mixing temperature is 35℃, the speed is 500 r / min, and the mixture is stirred for 15 min. Then, it is fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot shearing and cooling, 3×3 mm cylindrical particles are formed, which are the embedded components.

[0069] Example

[0070] Example 1

[0071] This embodiment provides a food packaging PE film, which is prepared by the following steps:

[0072] 40 kg of low-density polyethylene, 40 kg of anti-fogging masterbatch prepared in Preparation Example 1, 10 kg of embedded component prepared in Preparation Example 6, 2 kg of nano-lanthanum oxide and 2 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C, the speed was 500 r / min, and the mixture was stirred for 15 min.

[0073] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0074] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0075] Example 2

[0076] This embodiment provides a food packaging PE film, which is prepared by the following steps:

[0077] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 15 kg of embedded component prepared in Preparation Example 7, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C, the speed was 500 r / min, and the mixture was stirred for 15 min.

[0078] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0079] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0080] Example 3

[0081] This embodiment provides a food packaging PE film, which is prepared by the following steps:

[0082] 60 kg of low-density polyethylene, 60 kg of anti-fogging masterbatch prepared in Preparation Example 3, 20 kg of embedded component prepared in Preparation Example 8, 2 kg of nano-lanthanum oxide and 6 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C, the speed was 500 r / min, and the mixture was stirred for 15 min.

[0083] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0084] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0085] Example 4

[0086] This embodiment provides a food packaging PE film, which is prepared by the following steps:

[0087] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 4, 15 kg of embedded component prepared in Preparation Example 7, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0088] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0089] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0090] Example 5

[0091] This embodiment provides a food packaging PE film, which is prepared by the following steps:

[0092] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 5, 15 kg of embedded component prepared in Preparation Example 7, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0093] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0094] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0095] Example 6

[0096] This embodiment provides a food packaging PE film, which is prepared by the following steps:

[0097] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 15 kg of embedded component prepared in Preparation Example 9, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0098] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0099] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0100] Comparative Example

[0101] Comparative Example 1

[0102] This comparative example provides a food packaging PE film, which is prepared by the following steps:

[0103] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 15 kg of embedded component prepared in Preparation Example 10, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0104] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0105] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0106] Comparative Example 2

[0107] This comparative example provides a food packaging PE film, which is prepared by the following steps:

[0108] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 15 kg of embedded component prepared in Preparation Example 11, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0109] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0110] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0111] Comparative Example 3

[0112] This comparative example provides a food packaging PE film, which is prepared by the following steps:

[0113] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 15 kg of acrylic resin, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0114] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0115] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0116] Comparative Example 4

[0117] This comparative example provides a food packaging PE film, which is prepared by the following steps:

[0118] 65 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0119] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0120] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0121] Comparative Example 5

[0122] This comparative example provides a food packaging PE film, which is prepared by the following steps:

[0123] 115 kg of low-density polyethylene, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were put into a mixer. The mixing temperature was 35℃ and the speed was 500 r / min. The mixture was stirred for 15 min.

[0124] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0125] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0126] Comparative Example 6

[0127] This comparative example provides a food packaging PE film, which is prepared by the following steps:

[0128] 50 kg of low-density polyethylene, 50 kg of anti-fogging masterbatch prepared in Preparation Example 2, 15 kg of embedded component prepared in Preparation Example 12, 2 kg of nano-lanthanum oxide and 4 kg of nano-titanium dioxide were added to a mixer. The mixing temperature was 35°C and the speed was 500 r / min. The mixture was stirred for 15 min.

[0129] The material is then fed into a twin-screw extruder for melt extrusion granulation. The twin-screw extruder is divided into nine temperature zones, namely: 170℃, 180℃, 200℃, 210℃, 210℃, 215℃, 215℃, 210℃, and 205℃. The screw speed is 180 r / min. After hot cutting and cooling, 3×3 mm cylindrical granules are formed.

[0130] The prepared cylindrical particles were added to a casting equipment to form a film with a thickness of 25 μm.

[0131] Performance testing

[0132] Performance testing was performed on the PE films prepared in the examples and comparative examples.

[0133] 1. High-temperature anti-fogging performance:

[0134] Seal the mouth of a 500mL beaker containing 400mL of water. Place the beaker in a water bath at 60℃. A water film will appear on the surface of the PE film, followed by water droplets after a period of time. At this point, the corrosion resistance begins to decrease. Record the time from the start of the experiment to the appearance of water droplets to reflect the durability of high-temperature anti-fogging properties.

[0135] 2. Mechanical properties

[0136] Tensile strength and elongation at break were tested in accordance with GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets". The selected specimens were type 2 specimens with a width of 25 mm, and the tensile testing machine speed was 200 mm / min.

[0137] Table 1. Test Data for Examples and Comparative Examples

[0138]

[0139] As can be seen from Examples 2, 4, and 5 and Table 1, different added anti-fogging agents result in different anti-fogging performances, and a more suitable added anti-fogging agent can be selected.

[0140] As can be seen from Examples 2 and 6 and Table 1, the properties of polyethylene film can be adjusted by changing the type of macromolecular filler resin.

[0141] As can be seen from Examples 2, 1, 2 and 3 and Table 1, when polyethylene diamine and sodium stearate are used as extruders, the high temperature promotes amidation during the preparation of the embedded components, causing polyethylene diamine and sodium stearate to combine. This results in hydrophobic groups on the formed compound, which in turn causes the hydrophilic groups of the added antifogging agent to face the film surface, thereby further improving the antifogging performance of the film.

[0142] As can be seen from Examples 2, 3, 4, and 6, and Table 1, since the filler resin is a macromolecular substance, when the filler resin is mixed with low-density polyethylene, the macromolecular substance is more likely to remain inside the low-density polyethylene than the added anti-fogging agent. This forces the added anti-fogging agent to move to the film surface. Furthermore, the products of polyethylene diamine and sodium stearate, along with the macromolecular filler resin inside the polyethylene film, further promote the migration of the hydrophilic groups of the added anti-fogging agent to the surface of the polyethylene film, thereby enabling the added anti-fogging agent to play a role on the film surface and effectively improve the anti-fogging performance of the polyethylene film.

[0143] As can be seen from Examples 2, 4, and 5 and Table 1, by adding anti-fogging masterbatch and utilizing the anti-fogging agent contained in the anti-fogging masterbatch, the anti-fogging performance of polyethylene film can be effectively improved, reducing the environment for microbial growth and reproduction, thereby reducing the spoilage of fresh food.

[0144] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A PE packaging film, characterized in that, The raw materials include the following weight parts: low-density polyethylene 40-60 parts, anti-fog masterbatch 40-60 parts, inlaid component 10-20 parts, nano filler 4-8 parts, the inlaid component includes macromolecular filling resin and extrusion agent, the weight ratio of the macromolecular filling resin and the extrusion agent is 40:(1-2), the extrusion agent includes polyethylene diamine and sodium stearate, the weight ratio of the polyethylene diamine and the sodium stearate is 1:(1-3), the macromolecular filling resin is one of acrylic resin or polyurethane resin, the inlaid component is prepared by the following steps: mixing the macromolecular filling resin with the polyethylene diamine and the sodium stearate, and then extruding and granulating to obtain the inlaid component, the anti-fog masterbatch includes linear low-density polyethylene and internal anti-fog agent, the weight ratio of the linear low-density polyethylene and the internal anti-fog agent is 50:(1-3), the internal anti-fog agent is one of xylitol ester, sorbitol monopalmitate or glycerol monooleate, the nano filler includes nano lanthanum oxide and nano titanium dioxide, the weight ratio of the nano lanthanum oxide and the nano titanium dioxide is 1:(1-3).

2. The PE packaging film according to claim 1, characterized in that, The anti-fog masterbatch is prepared by the following steps: mixing and stirring the linear low-density polyethylene and the internal anti-fog agent, and then extruding and granulating to obtain the anti-fog masterbatch.

3. The process for the production of PE packaging films according to any one of claims 1 or 2, characterized in that, The method includes the following steps: mixing and stirring the low-density polyethylene, the anti-fog masterbatch, the inlaid component and the nano filler uniformly, and then extruding and granulating to obtain the masterbatch, and then the masterbatch is prepared into PE packaging film through a casting device.

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