Highly transparent polyethylene film and method for producing the same

Abstract

The present application relates to the technical field of plastic film, in particular to a kind of high transparent polyethylene film and preparation method thereof, the high transparent polyethylene film includes high density polyethylene 100 parts, ethylene-propylene rubber 6-10 parts, compatibilizer 2-5 parts, transparent agent 0.2-0.5 parts, antioxidant 0.5-2 parts, zinc stearate 0.1-0.5 parts by weight fraction;The film is premixed by gradient speed during preparation, double-screw melt extrusion is prepared master batch, casting film is formed.The present application uses zinc stearate as interface reagent, and ion bonding occurs in melt blending with compatibilizer, ion crosslinking network is constructed at the interface of high density polyethylene and ethylene-propylene rubber two phases, so as to enhance the interface compatibility, meanwhile, crystal structure is refined by means of transparent agent, and heat stability is improved by compounding antioxidant, finally, the film has high light transmittance, excellent tear strength and heat resistance, and the comprehensive performance is significantly better than traditional polyethylene film.

Description

Technical Field

[0001] This invention relates to the field of plastic film technology, specifically to a high-transparency polyethylene film and its preparation method. Background Technology

[0002] Polyethylene (PE) film is widely used in packaging, agriculture, and electronics due to its good chemical stability, low-temperature resistance, and processing fluidity. However, existing PE films have the following technical problems: ordinary PE films have high crystallinity, resulting in insufficient light transmittance (usually below 85%), which cannot meet the transparency requirements of high-end packaging and optics; the films have poor impact resistance and are prone to embrittlement and cracking at low temperatures; at the same time, their thermal stability is insufficient, and they are prone to thermal shrinkage deformation in environments above 60°C, limiting their application in high-temperature scenarios. Ethylene propylene diene monomer (EPDM) rubber, as a high-performance elastomer, has excellent high and low temperature resistance and elasticity. Blending it with PE can improve its mechanical properties, but due to the large difference in polarity between the two, direct blending leads to poor compatibility and reduces film transparency.

[0003] Therefore, developing a polyethylene film that can simultaneously achieve high transparency, high toughness, high heat resistance, and stable preparation process has become a key direction for overcoming the current technological bottlenecks. Summary of the Invention

[0004] To address the above issues, this invention proposes a high-transparency polyethylene film and its preparation method. Based on high-density polyethylene, EPDM rubber is introduced to enhance toughness. Furthermore, bis(p-methylbenzyl)sorbitol is introduced as a transparent agent, maleic anhydride-grafted polyolefin elastomer as a compatibilizer, and zinc stearate as an interfacial reactant. These components undergo ionic bonding reactions with the maleic anhydride graft during melt blending, thereby strengthening the interfacial compatibility and mechanical properties of high-density polyethylene and EPDM rubber. The use of a hindered phenolic antioxidant and phosphite antioxidant compound system significantly improves the film's thermo-oxidative stability, providing a more efficient solution for advancing film technology.

[0005] The technical solution of the present invention to achieve the above objectives is as follows:

[0006] This invention first provides a high-transparency polyethylene film, which comprises the following components by weight: 100 parts high-density polyethylene, 6-10 parts ethylene propylene diene monomer (EPDM) rubber, 2-5 parts compatibilizer, 0.2-0.5 parts transparent agent, 0.5-2 parts antioxidant, and 0.1-0.5 parts zinc stearate; the EPDM rubber comprises raw materials in the following mass ratio: ethylene monomer: propylene monomer: trimonomer ethyleneide norbornene = 0.8:1:0.05; the preparation method of the EPDM rubber includes the following steps:

[0007] S1: Weigh out ethylene monomer, propylene monomer and trimonomer ethylene-neobornene, and control the mass ratio of ethylene monomer, propylene monomer and trimonomer ethylene-neobornene to be 0.8:1:0.05. Mix and stir evenly to obtain the polymer monomer system.

[0008] S2: Transfer the monomer system to the polymerization reactor, purge the air with nitrogen, and then add a metallocene catalyst at a rate of 0.01-0.05% of the total mass of the monomer system to obtain the primary product of EPDM rubber.

[0009] S3: The obtained EPDM rubber primary product is subjected to vacuum distillation to remove unreacted monomer impurities, and a pure EPDM rubber substrate is obtained.

[0010] S4: Weigh out pure EPDM rubber substrate, add dicumyl peroxide vulcanizing agent at 0.8% of its mass, place it in a high-speed mixer, and mix for 6 minutes at 90°C to obtain the vulcanization pretreatment system.

[0011] S5: Transfer the obtained vulcanization pretreatment system to a flat vulcanizing machine and vulcanize it for 15 minutes at 160℃ and 10MPa. After vulcanization, cool the product to room temperature, cut off the scraps, and obtain EPDM rubber.

[0012] Furthermore, the compatibilizer is a maleic anhydride-grafted polyolefin elastomer with a grafting rate of 1.5-2.5%.

[0013] Furthermore, the transparent agent is a sorbitol derivative, specifically di(p-methylbenzyl)sorbitol.

[0014] Furthermore, the antioxidant is a compound of hindered phenolic antioxidants and phosphite antioxidants in a mass ratio of 1:1.

[0015] Furthermore, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite, with a mass ratio of 1:1.

[0016] This invention also provides a method for preparing a highly transparent polyethylene film, comprising the following steps:

[0017] A1: High-density polyethylene, EPDM rubber, compatibilizer and zinc stearate are premixed in a high-speed mixer with gradient speed. Initially, the speed is 500-600 r / min for 2-3 min, and then the speed is increased to 800-1000 r / min for 5-7 min. The total mixing time is controlled at 7-10 min to obtain a uniform premix.

[0018] A2: Add the premix to a twin-screw extruder, and at the same time add a transparent agent and an antioxidant in the middle section of the twin-screw extruder. Perform melt blending extrusion at an extrusion temperature of 160-190 ℃ and a screw speed of 300-400 r / min to obtain the extrudate. After cooling and pelletizing, the extrudate is obtained as blend masterbatch.

[0019] A3: The blended masterbatch is cast into a film using a casting film casting machine. The melting temperature is 170-200 ℃, the cooling roller temperature is 20-30 ℃, and the traction speed is 5-10 m / min to obtain a high-transparency polyethylene film.

[0020] Furthermore, in step A2, the temperatures of each section of the twin-screw extruder are set as follows: feeding section 160-170℃, compression section 170-180℃, melting section 180-190℃, and die head section 175-185℃.

[0021] Furthermore, in step A3, the cooling rollers of the casting film forming machine adopt dual-roller cooling, with the temperature of the first cooling roller being 25-30℃ and the temperature of the second cooling roller being 20-25℃.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The high-transparency polyethylene film prepared by this invention achieves synergistic optimization of transparency, mechanical properties and weather resistance by precisely controlling the component ratio and process parameters. Specifically, by introducing di(p-methylbenzyl)sorbitol as a transparentizing agent, it can effectively induce the formation of fine and uniform spherulitic structures in high-density polyethylene, significantly reducing light scattering. Simultaneously, the ionic bonding reaction between maleic anhydride-grafted polyolefin elastomer and zinc stearate during melt blending strengthens the interfacial adhesion between high-density polyethylene and EPDM rubber, improving the film's heat resistance and tear strength. Furthermore, the preparation of EPDM rubber utilizes a metallocene catalyst to regulate its molecular structure, ensuring that its ethylene content matches that of high-density polyethylene. The use of a 1:1 blend of hindered phenolic and phosphite antioxidants significantly enhances the film's thermo-oxidative stability, reducing degradation during processing and aging during long-term use, thus extending product lifespan. At the same time, the synergistic effect between the components allows the film to combine the rigidity and chemical resistance of high-density polyethylene with the weather resistance and flexibility of EPDM rubber, broadening its application range in food packaging, agricultural covering, industrial protection, and other scenarios.

[0024] Compared with existing technologies, the material of this invention has high transparency, excellent mechanical properties and wide applicability, solving the problems of insufficient transparency, difficulty in balancing performance and poor thermal stability of traditional polyethylene films. Attached Figure Description

[0025] Figure 1The light transmittance test results are for the highly transparent polyethylene films prepared in Examples 1-3 and Comparative Examples 1-3.

[0026] Figure 2 The tear strength test results are for the highly transparent polyethylene films prepared in Examples 1-3 and Comparative Examples 1-3.

[0027] Figure 3 The results are the heat distortion temperature performance test results of the high transparency polyethylene films prepared in Examples 1-3 and Comparative Examples 1-3.

[0028] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments in the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] Example 1: This example provides a high-transparency polyethylene film, which comprises the following components by weight: 100 parts high-density polyethylene, 6 parts EPDM rubber, 2 parts maleic anhydride-grafted polyolefin elastomer, 0.2 parts di(p-methylbenzyl)sorbitol, 0.5 parts a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite, and 0.1 parts zinc stearate. The EPDM rubber comprises raw materials in the following mass ratio: ethylene monomer: propylene monomer: trimonomer ethyleneide norbornene = 0.8:1:0.05. The specific preparation method includes the following steps:

[0031] S1: Weigh out ethylene monomer, propylene monomer and trimonomer ethylene-neobornene, and control the mass ratio of ethylene monomer, propylene monomer and trimonomer ethylene-neobornene to be 0.8:1:0.05. Mix and stir evenly to obtain the polymer monomer system.

[0032] S2: The monomer system is transferred to the polymerization reactor, nitrogen is introduced to purge the air, and then a metallocene catalyst is added at a rate of 0.01% of the total mass of the monomer system to obtain the primary product of EPDM rubber.

[0033] S3: The obtained EPDM rubber primary product is subjected to vacuum distillation to remove unreacted monomer impurities, and a pure EPDM rubber substrate is obtained.

[0034] S4: Weigh out pure EPDM rubber substrate, add dicumyl peroxide vulcanizing agent at 0.8% of its mass, place it in a high-speed mixer, and mix for 6 minutes at 90°C to obtain the vulcanization pretreatment system.

[0035] S5: Transfer the obtained vulcanization pretreatment system to a flat vulcanizing machine and vulcanize it for 15 minutes at 160℃ and 10MPa. After vulcanization, cool the product to room temperature, cut off the scraps, and obtain EPDM rubber.

[0036] This embodiment also provides a method for preparing a highly transparent polyethylene film, which specifically includes the following steps:

[0037] A1: 100 parts of high-density polyethylene, 6 parts of EPDM rubber, 2 parts of maleic anhydride-grafted polyolefin elastomer and 0.1 parts of zinc stearate were premixed in a high-speed mixer at a gradient speed. Initially, the mixing speed was 500 r / min for 3 min, and then the speed was increased to 800 r / min for 7 min to obtain a uniform premix.

[0038] A2: Add the premix to a twin-screw extruder, and simultaneously add 0.2 parts of di(p-methylbenzyl)sorbitol and 0.5 parts of a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in the middle section of the extruder. The temperature of each section of the twin-screw extruder is set as follows: feeding section 160℃, compression section 170℃, melting section 180℃, die head section 175℃, screw speed 300 r / min. After cooling and pelletizing, the extrudate is obtained as blend masterbatch.

[0039] A3: The blended masterbatch is cast into a film using a casting film casting machine. The melting temperature is 170℃, the temperature of the first cooling roller is 25℃, the temperature of the second cooling roller is 20℃, and the traction speed is 5 m / min, to obtain a high-transparency polyethylene film with a thickness of 50μm.

[0040] Example 2: This example provides a high-transparency polyethylene film, which comprises the following components by weight: 100 parts high-density polyethylene, 8 parts EPDM rubber, 3 parts maleic anhydride-grafted polyolefin elastomer, 0.35 parts di(p-methylbenzyl)sorbitol, 1.2 parts a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite, and 0.3 parts zinc stearate. The EPDM rubber comprises raw materials in the following mass ratio: ethylene monomer: propylene monomer: trimonomer ethyleneide norbornene = 0.8:1:0.05. The specific preparation method includes the following steps:

[0041] S1: Weigh out ethylene monomer, propylene monomer and trimonomer ethylene-neobornene, and control the mass ratio of ethylene monomer, propylene monomer and trimonomer ethylene-neobornene to be 0.8:1:0.05. Mix and stir evenly to obtain the polymer monomer system.

[0042] S2: The monomer system is transferred to the polymerization reactor, nitrogen is introduced to purge the air, and then a metallocene catalyst is added at a rate of 0.025% of the total mass of the monomer system to obtain the primary product of EPDM rubber.

[0043] S3: The obtained EPDM rubber primary product is subjected to vacuum distillation to remove unreacted monomer impurities, and a pure EPDM rubber substrate is obtained.

[0044] S4: Weigh out pure EPDM rubber substrate, add dicumyl peroxide vulcanizing agent at 0.8% of its mass, place it in a high-speed mixer, and mix for 6 minutes at 90°C to obtain the vulcanization pretreatment system.

[0045] S5: Transfer the obtained vulcanization pretreatment system to a flat vulcanizing machine and vulcanize it for 15 minutes at 160℃ and 10MPa. After vulcanization, cool the product to room temperature, cut off the scraps, and obtain EPDM rubber.

[0046] This embodiment also provides a method for preparing a highly transparent polyethylene film, which specifically includes the following steps:

[0047] A1: 100 parts of high-density polyethylene, 8 parts of EPDM rubber, 3 parts of maleic anhydride-grafted polyolefin elastomer and 0.3 parts of zinc stearate were premixed in a high-speed mixer at a gradient speed. Initially, the mixture was mixed at 550 r / min for 2.5 min, and then the speed was increased to 900 r / min for 6 min to obtain a uniform premix.

[0048] A2: Add the premix to a twin-screw extruder, and simultaneously add 0.35 parts of di(p-methylbenzyl)sorbitol and 1.2 parts of a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in the middle section of the extruder. The temperature of each section of the twin-screw extruder is set as follows: feeding section 165℃, compression section 175℃, melting section 185℃, die head section 180℃, screw speed 350 r / min. After cooling and pelletizing, the extrudate is obtained as blend masterbatch.

[0049] A3: The blended masterbatch is cast into a film using a casting film casting machine. The melting temperature is 185℃, the temperature of the first cooling roller is 28℃, the temperature of the second cooling roller is 22℃, and the traction speed is 8 m / min, to obtain a high-transparency polyethylene film with a thickness of 50μm.

[0050] Example 3: This example provides a high-transparency polyethylene film, which comprises the following components by weight: 100 parts high-density polyethylene, 10 parts EPDM rubber, 5 parts maleic anhydride-grafted polyolefin elastomer, 0.5 parts di(p-methylbenzyl)sorbitol, 2 parts a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite, and 0.5 parts zinc stearate. The EPDM rubber comprises raw materials in the following mass ratio: ethylene monomer: propylene monomer: trimonomer ethyleneide norbornene = 0.8:1:0.05. The specific preparation method includes the following steps:

[0051] S1: Weigh out ethylene monomer, propylene monomer and trimonomer ethylene-neobornene, and control the mass ratio of ethylene monomer, propylene monomer and trimonomer ethylene-neobornene to be 0.8:1:0.05. Mix and stir evenly to obtain the polymer monomer system.

[0052] S2: The polymerization monomer system is transferred to the polymerization reactor, nitrogen is introduced to purge the air, and then a metallocene catalyst is added at a rate of 0.05% of the total mass of the polymerization monomer system to obtain the primary product of EPDM rubber.

[0053] S3: The obtained EPDM rubber primary product is subjected to vacuum distillation to remove unreacted monomer impurities, and a pure EPDM rubber substrate is obtained.

[0054] S4: Weigh out pure EPDM rubber substrate, add dicumyl peroxide vulcanizing agent at 0.8% of its mass, place it in a high-speed mixer, and mix for 6 minutes at 90°C to obtain the vulcanization pretreatment system.

[0055] S5: Transfer the obtained vulcanization pretreatment system to a flat vulcanizing machine and vulcanize it for 15 minutes at 160℃ and 10MPa. After vulcanization, cool the product to room temperature, cut off the scraps, and obtain EPDM rubber.

[0056] This embodiment also provides a method for preparing a highly transparent polyethylene film, which specifically includes the following steps:

[0057] A1: 100 parts of high-density polyethylene, 10 parts of EPDM rubber, 5 parts of maleic anhydride-grafted polyolefin elastomer and 0.5 parts of zinc stearate are premixed in a high-speed mixer with gradient speed. Initially, the speed is 600 r / min for 2 min, and then the speed is increased to 1000 r / min for 5 min to obtain a uniform premix.

[0058] A2: Add the premix to a twin-screw extruder, and simultaneously add 0.5 parts of di(p-methylbenzyl)sorbitol and 2 parts of a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in the middle section of the extruder. The temperature of each section of the twin-screw extruder is set as follows: feeding section 170℃, compression section 180℃, melting section 190℃, die head section 185℃, screw speed 400 r / min. After cooling and pelletizing, the extrudate is obtained as blend masterbatch.

[0059] A3: The blended masterbatch is cast into a film using a casting film casting machine. The melting temperature is 200℃, the temperature of the first cooling roller is 30℃, the temperature of the second cooling roller is 25℃, and the traction speed is 10 m / min, to obtain a high-transparency polyethylene film with a thickness of 50μm.

[0060] Comparative Example 1

[0061] The only difference between Comparative Example 1 and Example 2 is that zinc stearate is not added.

[0062] Comparative Example 2

[0063] The only difference between Comparative Example 2 and Example 2 is that EPDM rubber is not added.

[0064] Comparative Example 3

[0065] The only difference between Comparative Example 3 and Example 2 is that the transparent agent di(p-methylbenzyl)sorbitol is not added.

[0066] Performance testing:

[0067] Transmittance test: Tested according to GB / T 2410-2008 "Determination of transmittance and haze of transparent plastics" using a spectrophotometer (UV-2600 type), with a test wavelength of 600nm and a scanning speed of 200nm / min. 50mm×50mm samples were cut and conditioned for 24 hours at 23℃±2℃ and 50%±5% relative humidity according to GB / T 2918-2018. Three test points were taken for each sample (12mm spacing, 5mm away from the edge), and the average value was recorded. The test results are as follows: Figure 1 As shown;

[0068] Tear strength test: According to the national standard GB / T 8809-2015 "Determination of tear resistance of plastic films - Part 1: Pants-shaped tear method", an electronic tensile testing machine (WDW-5 type) was used. The tensile speed was set to 100 mm / min. Five pants-shaped samples (dimensions: total length 150 mm, leg width 25 mm, slit length 50 mm) were prepared in both the film casting direction and the transverse direction. Three points were tested in each direction, and the average value was taken. The test results are as follows: Figure 2 As shown;

[0069] Heat distortion temperature test: According to the national standard GB / T 1634.1-2025 "Determination of Deformation Temperature of Plastics under Load - Part 1: General Test Methods", a heat distortion Vicat softening point tester (XRW-300 type) was used. A load of 0.45 MPa was applied, the heating rate was 120℃ / h, and the heat transfer medium was methyl silicone oil. The 80mm×10mm×4mm strip samples, which were hot-pressed, were conditioned for 24 hours at 23℃±2℃ and 50%±5% relative humidity before testing. Each sample was tested three times, and the average value was taken. The test results are as follows: Figure 3 As shown;

[0070] Data Analysis: From Figure 1-3 It can be seen that the high-transparency polyethylene films provided in Examples 1-3 of this invention have high light transmittance, excellent tear strength, and improved heat distortion temperature. Furthermore, Examples 2 and Comparative Examples 1-3 show that zinc stearate, EPDM rubber, and the transparent agent play a key regulatory role in the film's performance: Comparative Example 1 (without zinc stearate) suffers from insufficient interfacial compatibility between high-density polyethylene and EPDM rubber, leading to agglomeration of the dispersed phase of EPDM rubber, resulting in a light transmittance of only 82.3% and a tear strength of only 25.7 kN / m; Comparative Example 2 (without EPDM rubber) suffers from a sharp drop in tear strength to 19.2 kN / m and a heat distortion temperature of only 62.3℃ due to the lack of an elastic network, highlighting the supporting effect of EPDM rubber in simultaneously enhancing mechanical toughness and heat resistance stability through ethylene segment compatibility and elastic structure construction; Comparative Example 3 (without transparent agent) shows a light transmittance of 80.5%, corroborating the mechanism by which the transparent agent enhances light transmittance by inducing nanoscale spherulites and optimizing crystal distribution through heterogeneous nucleation.

[0071] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A highly transparent polyethylene film, characterized in that, By weight, it comprises the following components: 100 parts high-density polyethylene, 6-10 parts EPDM rubber, 2-5 parts compatibilizer, 0.2-0.5 parts transparent agent, 0.5-2 parts antioxidant, and 0.1-0.5 parts zinc stearate; The EPDM rubber comprises raw materials in the following mass ratio: ethylene monomer: propylene monomer: third monomer ethyleneide norbornene = 0.8: 1: 0.05; The preparation process of the EPDM rubber specifically includes the following steps: S1: Weigh out ethylene monomer, propylene monomer and third monomer ethylene norbornene, mix and stir evenly to obtain the polymer monomer system; S2: In the monomer polymerization system, a metallocene catalyst with an amount of 0.01%-0.05% of the total mass of the monomer polymerization system is added to carry out the reaction to obtain the primary product of EPDM rubber; S3: The primary EPDM rubber product is subjected to vacuum distillation to remove unreacted monomer impurities, resulting in a pure EPDM rubber substrate. S4: Weigh out pure EPDM rubber substrate and add dicumyl peroxide vulcanizing agent at 0.8% of its mass to perform pretreatment and obtain vulcanization pretreatment system; S5: The obtained vulcanization pretreatment system is vulcanized. After vulcanization, the product is cooled to room temperature and the scrap is removed by cutting to obtain EPDM rubber. The compatibilizer is a maleic anhydride-grafted polyolefin elastomer with a grafting rate of 1.5–2.5%; the transparent agent is di(p-methylbenzyl)sorbitol; and the antioxidant is a compound composed of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a 1:1 mass ratio.

2. A method for preparing a high-transparency polyethylene film according to claim 1, characterized in that, Includes the following steps: A1: High-density polyethylene, EPDM rubber, compatibilizer and zinc stearate are premixed at gradient speeds to obtain a uniform premix; A2: Add a transparent agent and an antioxidant to the premix, and perform melt blending and extrusion to obtain an extrudate. After cooling and pelletizing, the extrudate is obtained as blending masterbatch. A3: The blended masterbatch is cast into a film to obtain a highly transparent polyethylene film.

3. The method for preparing a high-transparency polyethylene film according to claim 2, characterized in that, The gradient speed premixing described in step A1 is carried out in a high-speed mixer; the co-extrusion described in step A2 is carried out in a twin-screw extruder; and the casting film formation described in step A3 is carried out in a casting film forming machine.

4. The method for preparing a high-transparency polyethylene film according to claim 3, characterized in that, The temperature settings for each section of the twin-screw extruder in step A2 are as follows: feeding section 160-170℃, compression section 170-180℃, melting section 180-190℃, and die head section 175-185℃.

5. The method for preparing a high-transparency polyethylene film according to claim 3, characterized in that, The cooling roller of the casting film forming machine described in step A3 adopts dual-roller cooling, with the temperature of the first cooling roller being 25-30℃ and the temperature of the second cooling roller being 20-25℃.

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