A polyethylene nonwoven material and a method of making the same

Abstract

The present application relates to a kind of polyethylene nonwoven material and its preparation method, polyethylene nonwoven material includes first spun-bonded layer, melt-blown layer and second spun-bonded layer, melt-blown layer is arranged between the first spun-bonded layer and the second spun-bonded layer, melt-blown layer is formed by the melt-blown spinning of first high melt index polyethylene and second high melt index polyethylene, the melt index of first high melt index polyethylene and second high melt index polyethylene is greater than or equal to 200g / 10min, and the melt index of first high melt index polyethylene and the second high melt index polyethylene is different.The present application is prepared melt-blown layer by melt-blown spinning using high melt index polyethylene, and using two different melt index high melt index polyethylene, the crystallization rate of different melt index polyethylene can be utilized fast and slow and flowability, play the role of molecular chain orientation in amorphous region in the process of crystallization by molecular entanglement, to improve the effect of fiber reinforcement, effectively solve the problem of low mechanical strength of melt-blown fiber.

Description

Technical Field

[0001] This invention relates to the field of nonwoven materials, specifically to a polyethylene nonwoven material and its preparation method. Background Technology

[0002] Irradiation sterilization is an effective method that uses electromagnetic waves generated by ionizing radiation to kill most microorganisms on materials. Radiations used for sterilization include electron beams, X-rays, and gamma rays. These can directly or indirectly destroy the ribonucleic acid, proteins, and enzymes of microorganisms, thereby killing them and achieving sterilization. Viruses can also be inactivated by high-energy radiation using the same principle. Compared with the widely used ethylene oxide sterilization technology, irradiation sterilization has advantages such as thorough sterilization, no pollution, no residue, fast speed, simple operation, and energy saving. It also has no special requirements for the direct packaging materials of products, allowing for packaging before irradiation to avoid the risk of secondary contamination. Furthermore, it allows for continuous operation, enabling large-scale product irradiation in a short time.

[0003] High-end medical protective clothing is a crucial barrier protecting healthcare workers and an essential resource for responding to major public safety incidents. Replacing existing ethylene oxide sterilization processes with irradiation sterilization will significantly increase the sterilization speed of protective clothing, reducing the sterilization time from 7-14 days to less than 1 day, and substantially shortening the supply cycle from production to hospitals. Currently, domestically produced protective clothing primarily uses polypropylene nonwoven fabric, but its radiation resistance is relatively poor.

[0004] High-density polyethylene (HDPE) nonwoven fabric exhibits excellent radiation resistance and high long-term storage stability after irradiation sterilization. Therefore, future production requires close collaboration across a longer industrial chain to manufacture high-specification protective clothing products suitable for irradiation sterilization processes. Polyethylene has a low melt index, high melt viscosity, and is not easily soluble in solvents at room temperature and pressure. Therefore, conventional spinning methods cannot process it into microfiber nonwoven materials.

[0005] Currently, high-end medical protective clothing is limited to Tyvek polyethylene flash-evaporated nonwoven fabric produced by DuPont in the United States. This fabric can withstand radiation sterilization, can be reused multiple times when necessary, and has the advantages of strong mechanical protection. However, the flash-evaporation process for high-end medical protective clothing requires large amounts of solvents, and the high-temperature, high-pressure manufacturing process places significant environmental pressure on production.

[0006] Chinese patent application number 202110392998.4 relates to a method for preparing antibacterial polyethylene nonwoven fabric and the polyethylene nonwoven fabric itself. The method includes the following steps: 1) preparing a spinning solution using high-density polyethylene, difluorochloromethane, and tetrafluorodichloroethane as raw materials; 2) preparing a polyethylene nonwoven fabric from the spinning solution obtained in step 1) using a flash spinning method; 3) preparing an antibacterial finishing agent and coating it onto the polyethylene nonwoven fabric for antibacterial treatment, thus obtaining an antibacterial polyethylene nonwoven fabric. The prepared polyethylene nonwoven fabric can be used in medical materials, food packaging materials, clothing materials, etc. However, as mentioned above, the flash spinning method for preparing polyethylene nonwoven fabric requires a large amount of solvent, high temperature and high pressure, making the process difficult and environmentally challenging.

[0007] Therefore, further research is needed on polyethylene nonwoven materials in this field. Summary of the Invention

[0008] The main objective of this invention is to provide a polyethylene nonwoven material and its preparation method, so as to overcome the defects of the existing polyethylene preparation process, such as complexity and environmental unfriendliness, and to overcome the problem of polypropylene nonwoven materials being unresistant to radiation.

[0009] To achieve the above objectives, the present invention provides a polyethylene nonwoven material, comprising a first spunbond layer, a meltblown layer, and a second spunbond layer, wherein the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer, and the meltblown layer is formed by meltblowing a first high melt index polyethylene and a second high melt index polyethylene, wherein the melt index of the first high melt index polyethylene and the second high melt index polyethylene are both greater than or equal to 200 g / 10min, and the melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are different.

[0010] The polyethylene nonwoven material of the present invention, wherein the melt index of the first high melt index polyethylene is 200~600 g / 10min, and the melt index of the second high melt index polyethylene is 1000~1500 g / 10min; the mass ratio of the first high melt index polyethylene to the second high melt index polyethylene is 5~20: 80~95.

[0011] The polyethylene nonwoven material of the present invention, wherein both the first spunbond layer and the second spunbond layer are polyethylene spunbond layers.

[0012] The polyethylene nonwoven material of the present invention further includes a spinning aid in the meltblown layer, wherein the spinning aid is at least one of dicumyl peroxide and 4,4'-thiobis(6-tert-butyl-3-methylphenol); the mass of the dicumyl peroxide is 0.01~0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene, and the mass of the 4,4'-thiobis(6-tert-butyl-3-methylphenol) is 0.1~0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene.

[0013] The polyethylene nonwoven material of the present invention has a tensile strength in both the transverse and longitudinal directions ≥80N and a moisture permeability >8000g / (m³). 2 •d), water pressure resistance >10kPa, blood resistance grade >3.

[0014] To achieve the above objectives, the present invention also provides a method for preparing a polyethylene nonwoven material, wherein the polyethylene nonwoven material comprises a first spunbond layer, a meltblown layer, and a second spunbond layer, and the preparation method includes:

[0015] Step 1: Mix and granulate the first high melt index polyethylene and the second high melt index polyethylene;

[0016] Step 2: The resin obtained in Step 1 is melt-blown spun to form a melt-blown layer on the first spunbond layer;

[0017] Step 3: Composite the second spunbond layer with the meltblown layer, so that the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer to obtain a polyethylene nonwoven material.

[0018] The method for preparing polyethylene nonwoven material according to the present invention, wherein the melt index of the first high melt index polyethylene and the second high melt index polyethylene are both greater than or equal to 200 g / 10min, and the melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are different.

[0019] The method for preparing polyethylene nonwoven material according to the present invention, wherein the melt index of the first high melt index polyethylene is 200~600 g / 10min, and the melt index of the second high melt index polyethylene is 1000~1500 g / 10min; the mass ratio of the first high melt index polyethylene to the second high melt index polyethylene is 5~20: 80~95.

[0020] The method for preparing polyethylene nonwoven material according to the present invention includes, in step 1, a spinning aid is added during the mixing and granulation process of the first high melt index polyethylene and the second high melt index polyethylene. The spinning aid is at least one of dicumyl peroxide and 4,4'-thiobis(6-tert-butyl-3-methylphenol). The mass of dicumyl peroxide is 0.01~0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene, and the mass of 4,4'-thiobis(6-tert-butyl-3-methylphenol) is 0.1~0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene.

[0021] The method for preparing polyethylene nonwoven material according to the present invention, wherein step 2 is carried out in a meltblown spinning machine, and the screw temperature is 200~240℃. o C, Hot air temperature is 230~260 o C, the conveying speed of the first spunbond layer and the movement speed of the mesh curtain are 20~100 m / min.

[0022] The beneficial effects of this invention are:

[0023] (1) The present invention uses high melt index polyethylene to prepare meltblown layer by meltblown spinning, and uses two high melt index polyethylenes with different melt indices. The different crystallization rates and fluidity of polyethylenes with different melt indices can be used to induce molecular chain orientation in the amorphous region during the crystallization process, thereby improving the fiber reinforcement and effectively solving the problem of low mechanical strength of meltblown fiber.

[0024] (2) In addition, the present invention utilizes polyethylene with different melt indexes to construct a molecular chain structure with a comb-like structure to further regulate the crystallization and orientation of the fiber, thereby further enhancing the strength of meltblown polyethylene microfiber.

[0025] (3) The polyethylene nonwoven material of the present invention has a spunbond layer-meltblown layer-spunbond layer structure, which has excellent barrier properties and safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the processing of meltblown-spunbond polyethylene microfiber nonwoven material.

[0027] Figure 2 This is a schematic diagram of the structure of spunbond-meltblown-spunbond polyethylene microfiber nonwoven material.

[0028] In the attached figures, the following labels are used:

[0029] 1 Feeding device

[0030] 2. Screw extruder

[0031] 3 Metering pump

[0032] 4. Web forming device

[0033] 5. Meltblown die head

[0034] 6 First spunbond layer

[0035] 7. Winding device Detailed Implementation

[0036] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.

[0037] This invention provides a polyethylene nonwoven material, comprising a first spunbond layer, a meltblown layer, and a second spunbond layer, wherein the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer. The meltblown layer is formed by meltblowing a first high melt index polyethylene and a second high melt index polyethylene. The melt index of both the first high melt index polyethylene and the second high melt index polyethylene is greater than or equal to 200 g / 10min (wherein, the melt index refers to the melt index tested at a load of 2.16 kg and a temperature of 190 °C), and the melt indices of the first high melt index polyethylene and the second high melt index polyethylene are different.

[0038] This invention uses high melt index polyethylene to prepare a meltblown layer through meltblown spinning. By using two high melt index polyethylenes with different melt indices, the different crystallization rates and fluidity of the polyethylenes can be utilized to induce molecular chain orientation in the amorphous region during the crystallization process, thereby improving the fiber reinforcement and effectively solving the problem of low mechanical strength of meltblown fibers.

[0039] In one embodiment, the melt index of the first high melt index polyethylene is 200-600 g / 10min, and the melt index of the second high melt index polyethylene is 1000-1500 g / 10min (the melt index was tested at a load of 2.16 kg and a temperature of 190°C). In another embodiment, the mass ratio of the first high melt index polyethylene to the second high melt index polyethylene is 5-20: 80-95.

[0040] In one embodiment, a spinning aid, such as a processing aid or antioxidant, is also added to the meltblown layer of the present invention. Specifically, the spinning aid is, for example, at least one of dicumyl peroxide and 4,4'-thiobis(6-tert-butyl-3-methylphenol); the mass of dicumyl peroxide is 0.01 to 0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene, and the mass of 4,4'-thiobis(6-tert-butyl-3-methylphenol) is 0.1 to 0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene.

[0041] In one embodiment, the spinning aid of the present invention is added during the mixing and granulation process of the first high melt index polyethylene and the second high melt index polyethylene. The spinning aid, such as dicumyl peroxide, preferentially reacts with the polyethylene with the higher melt index, inducing free radicals to form a polyethylene comb-chain structure with a relatively low melt index polyethylene as the backbone and a relatively high melt index polyethylene as the comb-like chain. The presence of this structure can efficiently induce nucleation during the polyethylene melt-blowing process, thereby inducing chain orientation under hot air micro-dragging to obtain self-reinforced polyethylene microfibers.

[0042] The first and second spunbond layers of this invention are prepared by spunbonding. This invention does not particularly limit the preparation process of the first and second spunbond layers; conventional preparation methods in the art are sufficient. In one embodiment, both the first and second spunbond layers of this invention are polyethylene spunbond layers.

[0043] The transverse and longitudinal tensile strength of the polyethylene nonwoven material of this invention is ≥80N, and the moisture permeability is >8000g / (m²). 2 •d) Water pressure resistance >10kPa, blood resistance rating >3. Protective clothing can be made from the polyethylene nonwoven material of this invention.

[0044] This invention also provides a method for preparing a polyethylene nonwoven material, the polyethylene nonwoven material comprising a first spunbond layer, a meltblown layer, and a second spunbond layer, the preparation method comprising:

[0045] Step 1: Mix and granulate the first high melt index polyethylene and the second high melt index polyethylene;

[0046] Step 2: The resin obtained in Step 1 is melt-blown spun to form a melt-blown layer on the first spunbond layer;

[0047] Step 3: Composite the second spunbond layer with the meltblown layer, so that the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer to obtain a polyethylene nonwoven material.

[0048] This invention involves directly meltblowing a meltblown layer onto a first spunbond layer, and then combining it with a second spunbond layer to obtain a polyethylene nonwoven material with a spunbond-meltblown-spunbond structure. This nonwoven material exhibits excellent barrier properties and safety.

[0049] In one embodiment, the melt indexes of both the first high melt index polyethylene and the second high melt index polyethylene are greater than or equal to 200 g / 10 min, and the melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are different. In another embodiment, the melt index of the first high melt index polyethylene is 200~600 g / 10 min, and the melt index of the second high melt index polyethylene is 1000~1500 g / 10 min, wherein the melt indexes are tested under a load of 2.16 kg and a temperature of 190 °C; the mass ratio of the first high melt index polyethylene to the second high melt index polyethylene is 5~20: 80~95.

[0050] This invention does not particularly limit the mixing and granulation process of the first high melt index polyethylene and the second high melt index polyethylene. In one embodiment, the mixing and granulation of the first high melt index polyethylene and the second high melt index polyethylene are carried out in a twin-screw extruder, and the temperature of the screw feed section to homogenization section is set at 110~140℃. o C, the screw speed is, for example, 30-100 rpm.

[0051] In one embodiment, a spinning aid, such as a processing aid or antioxidant, is added during the mixing and granulation process of the first and second high melt index polyethylene in step 1. Specifically, the spinning aid is at least one of dicumyl peroxide and 4,4'-thiobis(6-tert-butyl-3-methylphenol); the mass of dicumyl peroxide is 0.01 to 0.2% of the sum of the masses of the first and second high melt index polyethylenes, and the mass of 4,4'-thiobis(6-tert-butyl-3-methylphenol) is 0.1 to 0.2% of the sum of the masses of the first and second high melt index polyethylenes.

[0052] The first and second spunbond layers of this invention are prepared by spunbonding. This invention does not particularly limit the preparation process of the first and second spunbond layers; conventional preparation methods in the art are sufficient. In one embodiment, both the first and second spunbond layers of this invention are polyethylene spunbond layers.

[0053] The meltblown layer is formed directly on the first spunbond layer. In one embodiment, the first high melt index polyethylene and the second high melt index polyethylene are mixed, granulated, and then fed into a meltblown spinning machine with a screw temperature of 200-240°C. o C. Hot air temperature is 230~260°C oC. The polyethylene microfibers obtained by meltblowing are deposited onto the first spunbond layer in the web-forming device, forming a nonwoven material with a spunbond-meltblown structure. In another embodiment, the conveying speed of the first spunbond layer and the movement speed of the web are 20~100 m / min.

[0054] The processing procedure for the meltblown-spunbond polyethylene microfiber nonwoven material of this invention is as follows: Figure 1 As shown, but the present invention is not limited thereto. First high melt index polyethylene and second high melt index polyethylene enter the screw extruder 2 through the feeding device 1. After extrusion and granulation, the composite resin passes through the metering pump 3 and the meltblown die 5, and settles on the web forming device 4. The first spunbond layer 6 is conveyed to the web forming device 4. The polyethylene microfibers obtained by meltblowing settle on the first spunbond layer 6 on the web forming device 4. The resulting spunbond-meltblown nonwoven material is wound up by the winding device 7.

[0055] Finally, the second spunbond layer is combined with the meltblown layer, that is, the second spunbond layer is combined with the side of the meltblown layer in the spunbond-meltblown structure opposite to the first spunbond layer, so that the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer, to obtain a polyethylene nonwoven material.

[0056] The present invention does not specifically limit the composite process of the second spunbond layer and the meltblown layer; conventional processes in the art are sufficient.

[0057] The polyethylene nonwoven material of this invention not only has high mechanical properties and high filtration performance, but also good barrier properties and radiation resistance. When electron beam radiation sterilization or X-ray sterilization is selected, the dosage is controlled at 16~27 kgy, and there are no Escherichia coli colonies, bacterial colonies, fungal colonies, etc. after irradiation.

[0058] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0059] Source of raw materials or equipment:

[0060] (1) Raw materials:

[0061] High melt index polyethylene was provided by the Daqing Chemical Research Center of China National Petroleum Corporation.

[0062] Dicumyl peroxide, manufactured by Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0063] The antioxidant 4,4'-thiobis(6-tert-butyl-3-methylphenol) is produced by Wuhan Smike Biotechnology Co., Ltd.

[0064] (2) Equipment:

[0065] The kneading and mixing equipment was designed and manufactured by Donghua University.

[0066] Meltblown spinning machines are manufactured by Tuoren Group;

[0067] The X-ray irradiation equipment was manufactured by Bruker GmbH in Germany.

[0068] Example 1

[0069] 1) Preparation of polyethylene composite resin:

[0070] 15 kg of polyethylene powder with a melt index of 200 g / 10 min, 85 kg of polyethylene powder with a melt index of 1000 g / 10 min, 0.1 kg of dicumyl peroxide, and 0.1 kg of 4,4'-thiobis(6-tert-butyl-3-methylphenol) were thoroughly mechanically premixed and then added to a twin-screw extruder for reactive extrusion to obtain a composite resin. The temperature of the screw feed section to the homogenization section was set at 110-140°C. o C, screw speed 50 rpm.

[0071] 2) Preparation of meltblown-spunbond polyethylene microfiber composite nonwoven material:

[0072] A feeding device for the first spunbond polyethylene nonwoven fabric is added to the rear end of the meltblown spinning machine of the Tuoren Group, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene nonwoven fabric (e.g., Figure 1 (As shown). The first spunbond polyethylene nonwoven fabric is fed at a speed of 30 m / min, and the meltblown assembly temperature is 200°C. o C, Hot air temperature set to 260 o C. The hot air frequency is set to 45Hz, and the receiving distance is 25cm. After the above operations, a double-layer nonwoven material is obtained, with the first spunbond nonwoven fabric as the base and the meltblown nonwoven fabric as the load layer. The weight ratio of the first spunbond layer to the meltblown layer is controlled at 3~10: 90~97. Figure 2 As shown.

[0073] 3) Spunbond-meltblown-spunbond polyethylene microfiber nonwoven material:

[0074] The double-layer nonwoven material obtained through the above steps is then laminated with a second spunbond polyethylene nonwoven fabric, and hot-rolled to obtain a polyethylene nonwoven material. Protective clothing made from this polyethylene nonwoven material exhibits a tensile strength of 85 N in both the transverse and longitudinal directions, and a moisture permeability greater than 8200 g / (m²). 2 •d) Water pressure resistance >11kPa, blood pressure resistance level >3. The protective suit's performance remained unchanged after sterilization by 16 kgy electron beam radiation.

[0075] Example 2

[0076] 1) Preparation of polyethylene composite resin:

[0077] 20 kg of polyethylene powder with a melt index of 400 g / 10 min, 80 kg of polyethylene powder with a melt index of 1200 g / 10 min, 0.01 kg of dicumyl peroxide, and 0.1 kg of 4,4'-thiobis(6-tert-butyl-3-methylphenol) were thoroughly mechanically premixed and then added to a twin-screw extruder for reactive extrusion to obtain a composite resin. The temperature of the screw feed section to the homogenization section was set at 110-140°C. o C, screw speed 100 rpm.

[0078] 2) Preparation of meltblown-spunbond polyethylene microfiber composite nonwoven material:

[0079] A spunbond polyethylene nonwoven fabric feeding device is added to the rear end of the meltblown spinning machine of Tuoren Group, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene nonwoven fabric. The feeding speed of the first spunbond polyethylene nonwoven fabric is 20 m / min, and the temperature of the meltblown assembly is 210°C. o C, Hot air temperature set to 250 o C. The hot air frequency is set to 45Hz, and the receiving distance is 25cm. After the above operations, a double-layer nonwoven material is obtained with the first spunbond nonwoven fabric as the base and the meltblown nonwoven fabric as the load layer. The weight ratio of the first spunbond layer to the meltblown layer is controlled at 3~10: 90~97.

[0080] 3) Spunbond-meltblown-spunbond polyethylene microfiber nonwoven material:

[0081] The double-layer nonwoven material obtained through the above steps is then laminated with a second spunbond polyethylene nonwoven fabric, and hot-rolled to obtain a polyethylene nonwoven material. Protective clothing made from this polyethylene nonwoven material exhibits a tensile strength of 93 N in both the transverse and longitudinal directions, and a moisture permeability >8000 g / (m²). 2 •d) Water pressure resistance >13kPa, blood pressure resistance level >3. The protective suit's performance remains undiminished after sterilization with 27 kgy X-rays.

[0082] Example 3

[0083] 1) Preparation of polyethylene composite resin:

[0084] 17 kg of polyethylene powder with a melt index of 600 g / 10 min, 83 kg of polyethylene powder with a melt index of 1500 g / 10 min, 0.1 kg of dicumyl peroxide, and 0.2 kg of 4,4'-thiobis(6-tert-butyl-3-methylphenol) were thoroughly mechanically premixed and then added to a twin-screw extruder for reactive extrusion to obtain a composite resin. The temperature of the screw feed section to the homogenization section was set at 110-140°C. o C, screw speed 75 rpm.

[0085] 2) Preparation of meltblown-spunbond polyethylene microfiber composite nonwoven material:

[0086] A spunbond polyethylene nonwoven fabric feeding device is added to the rear end of the meltblown spinning machine of Tuoren Group, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene nonwoven fabric. The feeding speed of the first spunbond polyethylene nonwoven fabric is 30 m / min, and the temperature of the meltblown assembly is 220°C. o C, Hot air temperature set to 250 o C. The hot air frequency is set to 45Hz, and the receiving distance is 30cm. After the above operations, a double-layer nonwoven material is obtained with the first spunbond nonwoven fabric as the base and the meltblown nonwoven fabric as the load layer. The weight ratio of the first spunbond layer to the meltblown layer is controlled at 3~10: 90~97.

[0087] 3) Spunbond-meltblown-spunbond polyethylene microfiber nonwoven material:

[0088] The double-layer nonwoven material obtained through the above steps is then laminated with a second spunbond polyethylene nonwoven fabric, and hot-rolled to obtain a polyethylene nonwoven material. Protective clothing made from this polyethylene nonwoven material exhibits a tensile strength of 87 N in both the transverse and longitudinal directions, and a moisture permeability greater than 8500 g / (m²). 2 •d) Water pressure resistance >11kPa, blood resistance grade >3. The protective suit's performance remains undiminished after sterilization with 25 kgy X-rays.

[0089] Example 4

[0090] 1) Preparation of polyethylene composite resin:

[0091] 15 kg of polyethylene powder with a melt index of 400 g / 10 min, 85 kg of polyethylene powder with a melt index of 1100 g / 10 min, 0.01 kg of dicumyl peroxide, and 0.15 kg of 4,4'-thiobis(6-tert-butyl-3-methylphenol) were thoroughly mechanically premixed and then added to a twin-screw extruder for reactive extrusion to obtain a composite resin. The temperature of the screw feed section to the homogenization section was set at 110-140°C. o C, screw speed 100 rpm.

[0092] 2) Preparation of meltblown-spunbond polyethylene microfiber composite nonwoven material:

[0093] A spunbond polyethylene nonwoven fabric feeding device is added to the rear end of the meltblown spinning machine of Tuoren Group, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene nonwoven fabric. The feeding speed of the first spunbond polyethylene nonwoven fabric is 50 m / min, and the temperature of the meltblown assembly is 240°C. o C, Hot air temperature set to 230 oC. The hot air frequency is set to 45Hz, and the receiving distance is 30cm. After the above operations, a double-layer nonwoven material is obtained with the first spunbond nonwoven fabric as the base and the meltblown nonwoven fabric as the load layer. The weight ratio of the first spunbond layer to the meltblown layer is controlled at 3~10: 90~97.

[0094] 3) Spunbond-meltblown-spunbond polyethylene microfiber nonwoven material:

[0095] The double-layer nonwoven material obtained through the above steps is then laminated with a second spunbond polyethylene nonwoven fabric, and hot-rolled to obtain a polyethylene nonwoven material. Protective clothing made from this polyethylene nonwoven material exhibits a tensile strength of 89 N in both the transverse and longitudinal directions, and a moisture permeability greater than 8300 g / (m²). 2 •d) Water pressure resistance >12kPa, blood pressure resistance level >3. The protective suit's performance remains undiminished after electron beam radiation sterilization.

[0096] Example 5

[0097] 1) Preparation of polyethylene composite resin:

[0098] Five kg of polyethylene powder with a melt index of 400 g / 10 min, 95 kg of polyethylene powder with a melt index of 1100 g / 10 min, 0.01 kg of dicumyl peroxide, and 0.15 kg of 4,4'-thiobis(6-tert-butyl-3-methylphenol) were thoroughly mechanically premixed and then added to a twin-screw extruder for reactive extrusion to obtain a composite resin. The temperature of the screw feed section to the homogenization section was set at 110-140°C. o C, screw speed 100 rpm.

[0099] 2) Preparation of meltblown-spunbond polyethylene microfiber composite nonwoven material:

[0100] A spunbond polyethylene nonwoven fabric feeding device is added to the rear end of the meltblown spinning machine of Tuoren Group, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene nonwoven fabric. The feeding speed of the first spunbond polyethylene nonwoven fabric is 50 m / min, and the temperature of the meltblown assembly is 240°C. o C, Hot air temperature set to 230 o C. The hot air frequency is set to 45Hz, and the receiving distance is 30cm. After the above operations, a double-layer nonwoven material is obtained with the first spunbond nonwoven fabric as the base and the meltblown nonwoven fabric as the load layer. The weight ratio of the first spunbond layer to the meltblown layer is controlled at 3~10: 90~97.

[0101] 3) Spunbond-meltblown-spunbond polyethylene microfiber nonwoven material:

[0102] The double-layer nonwoven material obtained through the above steps is then laminated with a second spunbond polyethylene nonwoven fabric, and hot-rolled to obtain a polyethylene nonwoven material. Protective clothing made from this polyethylene nonwoven material exhibits a tensile strength of 86 N in both the transverse and longitudinal directions, and a moisture permeability greater than 8400 g / (m²). 2 •d) Water pressure resistance >12kPa, blood pressure resistance level >3. The protective suit's performance remains undiminished after electron beam radiation sterilization.

[0103] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A polyethylene nonwoven material, characterized in that, It includes a first spunbond layer, a meltblown layer, and a second spunbond layer, wherein the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer, and the meltblown layer is formed by meltblowing a first high melt index polyethylene and a second high melt index polyethylene, wherein the melt index of the first high melt index polyethylene is 200~600 g / 10min, and the melt index of the second high melt index polyethylene is 1000~1500 g / 10min; The meltblown layer also contains a spinning aid, which is at least one of dicumyl peroxide and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

2. The polyethylene nonwoven material according to claim 1, characterized in that, The mass ratio of the first high melt index polyethylene to the second high melt index polyethylene is 5~20: 80~95.

3. The polyethylene nonwoven material according to claim 1, characterized in that, Both the first spunbond layer and the second spunbond layer are polyethylene spunbond layers.

4. The polyethylene nonwoven material according to claim 1, characterized in that, The mass of the dicumyl peroxide is 0.01 to 0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene, and the mass of the 4,4'-thiobis(6-tert-butyl-3-methylphenol) is 0.1 to 0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene.

5. The polyethylene nonwoven material according to claim 1, characterized in that, The polyethylene nonwoven material has a transverse and longitudinal tensile strength ≥80N and a moisture permeability >8000g / (m³). 2 •d), water pressure resistance >10kPa, blood resistance grade >3.

6. A method for preparing a polyethylene nonwoven material, characterized in that, The polyethylene nonwoven material comprises a first spunbond layer, a meltblown layer, and a second spunbond layer, and is prepared by means of: Step 1: Mix and granulate the first high melt index polyethylene, the second high melt index polyethylene, and the spinning aid; Step 2: The resin obtained in Step 1 is melt-blown spun to form a melt-blown layer on the first spunbond layer; Step 3: Composite the second spunbond layer with the meltblown layer, so that the meltblown layer is sandwiched between the first spunbond layer and the second spunbond layer to obtain a polyethylene nonwoven material; Wherein, the melt index of the first high melt index polyethylene is 200~600 g / 10min, and the melt index of the second high melt index polyethylene is 1000~1500 g / 10min; the spinning aid is at least one of dicumyl peroxide and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

7. The method for preparing polyethylene nonwoven material according to claim 6, characterized in that, The mass ratio of the first high melt index polyethylene to the second high melt index polyethylene is 5~20: 80~95.

8. The method for preparing polyethylene nonwoven material according to claim 6, characterized in that, The mass of the dicumyl peroxide is 0.01 to 0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene, and the mass of the 4,4'-thiobis(6-tert-butyl-3-methylphenol) is 0.1 to 0.2% of the sum of the masses of the first high melt index polyethylene and the second high melt index polyethylene.

9. The method for preparing polyethylene nonwoven material according to claim 6, characterized in that, Step 2 is performed in a meltblown spinning machine with a screw temperature of 200~240°C. o C, Hot air temperature is 230~260 o C, the conveying speed of the first spunbond layer and the movement speed of the mesh curtain are 20~100 m / min.

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