Polyethylene non-woven material and preparation method thereof

Abstract

The invention relates to a polyethylene non-woven material and a preparation method thereof.The polyethylene non-woven material comprises a first spunbond layer, a melt-blown layer and a second spunbond layer, and the melt-blown layer is clamped between the first spunbond layer and the second spunbond layer; the melt-blown layer is formed by performing melt-blown spinning on first high-melt-index polyethylene and second high-melt-index polyethylene, the melt indexes of the first high-melt-index polyethylene and the second high-melt-index polyethylene are both greater than or equal to 200g / 10min, and the melt indexes of the first high-melt-index polyethylene and the second high-melt-index polyethylene are different. The melt-blown layer is prepared from the high-melt-index polyethylene through melt-blown spinning, the two kinds of high-melt-index polyethylene with different melt indexes are adopted, the crystallization rate and fluidity of the polyethylene with the different melt indexes can be utilized, and the effect of binding molecules in an amorphous area to induce molecular chain orientation in the crystallization process is achieved; therefore, the fiber reinforcement effect is improved, and the problem of low mechanical strength of melt-blown fibers is effectively solved.

Description

Technical Field

[0001] The invention relates to the field of nonwoven materials, and in particular to a polyethylene nonwoven material and a preparation method thereof. Background Art

[0002] Irradiation sterilization is an effective method of killing microorganisms on most substances by using electromagnetic waves generated by ionizing radiation. The rays used for sterilization include electron beams, X-rays, and gamma rays. They can directly or indirectly destroy the RNA, proteins, and enzymes of microorganisms, thereby killing microorganisms and playing a sterilizing role. In the same principle, viruses can also be inactivated by high-energy rays. Compared with the widely used ethylene oxide sterilization technology, irradiation sterilization has the advantages of thorough sterilization, no pollution, no residue, fast speed, easy operation, and energy saving. There are no special requirements for the direct packaging materials of the product. It can be irradiated after packaging to avoid the risk of secondary contamination. It can also operate continuously and complete large-scale product irradiation in a short time.

[0003] High-end medical protective clothing is an important barrier to protect medical and health workers, and is an important strategic material necessary for the country to respond to major public safety incidents. Using radiation sterilization to replace the existing ethylene oxide disinfection and sterilization process will greatly increase the sterilization speed of protective clothing, reducing the sterilization time from 7 to 14 days to less than 1 day, and significantly shortening the supply cycle of protective clothing from production to hospitals. At present, domestic protective clothing materials are basically based on polypropylene non-woven fabrics, but their radiation resistance is poor.

[0004] High-density polyethylene nonwoven fabrics have good radiation resistance and high long-term storage stability after radiation sterilization. Therefore, in the future, close cooperation with a longer industry chain is needed to produce high-standard protective clothing products suitable for radiation sterilization. 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] At present, high-end medical protective clothing is limited to Tyvek polyethylene flash non-woven fabrics produced by DuPont in the United States. It can withstand radiation sterilization and can be reused many times when necessary. It has the advantages of strong mechanical strength and high protective performance. However, the flash process of high-end medical protective clothing requires a large amount of solvents, and the high temperature and high pressure preparation process brings great environmental pressure to production.

[0006] The Chinese patent application with application number 202110392998.4 relates to a method for preparing antibacterial polyethylene non-woven fabric and polyethylene non-woven fabric. The method comprises the following steps: 1) using high-density polyethylene, difluorochloromethane, and tetrafluorodichloroethane as raw materials to prepare a spinning solution; 2) preparing the spinning solution obtained in step 1) by flash spinning to form a polyethylene non-woven fabric; 3) preparing an antibacterial finishing agent, applying it to the polyethylene non-woven fabric for antibacterial treatment, and obtaining an antibacterial polyethylene non-woven fabric. The prepared polyethylene non-woven fabric can be used in medical materials, food packaging materials, clothing materials, etc. However, as mentioned above, the flash spinning method is used to prepare polyethylene non-woven fabrics. The flash evaporation process requires a large amount of solvent, high temperature and high pressure, and the process is difficult and the environmental pressure is high.

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

[0008] The main purpose of the present invention is to provide a polyethylene nonwoven material and a preparation method thereof, so as to overcome the defects of the polyethylene preparation process in the prior art, such as complex process and unfriendly environment, and to overcome the problem that the polypropylene nonwoven material is not resistant to radiation.

[0009] In order to achieve the above-mentioned object, 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 indexes of the first high melt index polyethylene and the second high melt index polyethylene are both 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.

[0010] The polyethylene nonwoven material of the present invention, wherein 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; 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 the first spunbond layer and the second spunbond layer are both polyethylene spunbond layers.

[0012] The polyethylene nonwoven material of the present invention further comprises a spinning aid added to 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 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.

[0013] The polyethylene nonwoven material of the present invention has a transverse and longitudinal breaking strength of ≥80N and a moisture permeability of ≥8000g / (m 2 ·d), water pressure resistance>10kPa, blood resistance>3 levels.

[0014] In order to achieve the above object, 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 comprises:

[0015] Step 1, mixing and granulating the first high melt index polyethylene and the second high melt index polyethylene;

[0016] Step 2, melt-blowing the resin obtained in step 1 to form a melt-blown layer on the first spunbond layer;

[0017] Step 3: Compounding 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 the polyethylene nonwoven material of the present invention, wherein the melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are both 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.

[0019] The method for preparing the polyethylene nonwoven material of the present invention comprises the following steps: the melt index of the first high melt index polyethylene is 200-600 g / 10 min, the melt index of the second high melt index polyethylene is 1000-1500 g / 10 min; and 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 a polyethylene nonwoven material of the present invention comprises the following steps: in step 1, a spinning aid is added during the mixing and granulation of the first high melt index polyethylene and the second high melt index polyethylene, 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.

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

[0022] Beneficial effects of the present invention:

[0023] (1) The present invention adopts high melt index polyethylene to prepare the meltblown layer by melt-blown spinning, and adopts two high melt index polyethylenes with different melt indices. The different crystallization rates and fluidities of polyethylenes with different melt indices can be utilized to play the role of inducing molecular chain orientation in the amorphous region during the crystallization process, thereby improving the fiber reinforcement effect and effectively solving the problem of low mechanical strength of meltblown fibers.

[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 the meltblown polyethylene microfibers.

[0025] (3) The polyethylene nonwoven material of the present invention has a spunbond layer-meltblown layer-spunbond layer structure and has excellent barrier properties and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the processing process of melt-blown-spunbonded polyethylene microfiber nonwoven material;

[0027] Figure 2 Schematic diagram of the structure of spunbond-meltblown-spunbond polyethylene microfiber nonwoven material.

[0028] Wherein, the reference numerals are:

[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 DESCRIPTION

[0036] The technical scheme of the present invention is described in detail below. The following implementation modes are implemented on the premise of the technical scheme 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 implementation modes. The structures or experimental methods of specific conditions are not specified in the following implementation modes, and generally conventional conditions are followed.

[0037] 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 indexes of the first high melt index polyethylene and the second high melt index polyethylene are both greater than or equal to 200 g / 10 min (wherein the melt index refers to the melt index tested under a load of 2.16 kg and a temperature of 190° C.), and the melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are different.

[0038] The present invention adopts high melt index polyethylene to prepare the meltblown layer through melt-blown spinning, and adopts two high melt index polyethylenes with different melt indices. The crystallization rate and fluidity of polyethylenes with different melt indices can be utilized to play the role of inducing molecular chain orientation by binding molecules in the amorphous region during the crystallization process, thereby improving the fiber reinforcement effect 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 / 10 min, and the melt index of the second high melt index polyethylene is 1000-1500 g / 10 min (the melt index is 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 is further added to the meltblown layer of the present invention, which may be a processing aid, an antioxidant, etc. 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 0.01-0.2% of the sum of the mass 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 mass 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 mixed granulation process of the first high melt index polyethylene and the second high melt index polyethylene. The spinning aid of the present invention, such as dicumyl peroxide, preferentially reacts with the polyethylene with a higher melt index to induce free radicals, forming a polyethylene comb chain structure with a relatively low melt index polyethylene as the skeleton and a relatively high melt index polyethylene as the comb chain. The existence of this structure can efficiently induce the nucleation effect of the polyethylene melt-blowing process, thereby inducing chain orientation under hot air micro-drafting to obtain self-reinforced polyethylene microfibers.

[0042] The first spunbond layer and the second spunbond layer of the present invention are prepared by a spunbond method. The present invention does not particularly limit the preparation process of the first spunbond layer and the second spunbond layer, and conventional preparation methods in the art can be used. In one embodiment, the first spunbond layer and the second spunbond layer of the present invention are both polyethylene spunbond layers.

[0043] The polyethylene nonwoven material of the present invention has a transverse and longitudinal breaking strength of ≥80N and a moisture permeability of ≥8000g / (m 2 ·d), water pressure resistance>10 kPa, blood resistance>level 3. Protective clothing can be prepared from the polyethylene nonwoven material of the present invention.

[0044] 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 comprises:

[0045] Step 1, mixing and granulating the first high melt index polyethylene and the second high melt index polyethylene;

[0046] Step 2, melt-blowing the resin obtained in step 1 to form a melt-blown layer on the first spunbond layer;

[0047] Step 3: Compounding 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] The present invention melt-blown the melt-blown layer directly on the first spunbond layer, and then composite it with the second spunbond layer to obtain a polyethylene nonwoven material with a spunbond-melt-blown-spunbond structure. The nonwoven material has excellent barrier properties and safety.

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

[0050] The present 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 the homogenizing section is set at 110 to 140°C, and the screw speed is, for example, 30-100rpm.

[0051] In one embodiment, in step 1, a spinning aid is added during the mixing and granulation of the first high melt index polyethylene and the second high melt index polyethylene, which may be a processing aid, an antioxidant, etc. 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 0.01-0.2% of the sum of the mass 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 mass of the first high melt index polyethylene and the second high melt index polyethylene.

[0052] The first spunbond layer and the second spunbond layer of the present invention are prepared by a spunbond method. The present invention does not particularly limit the preparation process of the first spunbond layer and the second spunbond layer, and conventional preparation methods in the art can be used. In one embodiment, the first spunbond layer and the second spunbond layer of the present invention are both polyethylene spunbond layers.

[0053] The meltblown layer is directly formed on the first spunbond layer. In one embodiment, after the first high melt index polyethylene and the second high melt index polyethylene are mixed and granulated, they enter the meltblown spinning machine, the screw temperature is 200-240°C, the hot air temperature is 230-260°C, and the polyethylene microfibers obtained by meltblowing are deposited on the input first spunbond layer on the web forming device to form a nonwoven material of spunbond-meltblown structure. In another embodiment, the conveying speed of the first spunbond layer and the moving speed of the mesh curtain are 20-100 m / min.

[0054] The processing of the meltblown-spunbonded polyethylene microfiber nonwoven material of the present invention is as follows: Figure 1 As shown, but the present invention is not limited thereto. The first high melt index polyethylene and the second high melt index polyethylene enter the screw extruder 2 through the feeding device 1, and the composite resin is extruded and granulated, and then passes through the metering pump 3 and the melt-blowing die head 5, and settles on the web-forming device 4. The first spunbond layer 6 is transported to the web-forming device 4, and the polyethylene microfibers obtained by melt-blowing are settled on the first spunbond layer 6 on the web-forming device 4, and the obtained nonwoven material of spunbond-melt-blown structure is wound up by the winding device 7.

[0055] Finally, the second spunbond layer is compounded with the meltblown layer, that is, the second spunbond layer is compounded to 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 particularly limit the composite process of the second spunbond layer and the meltblown layer, and conventional processes in the art may be used.

[0057] The polyethylene nonwoven material of the present invention not only has high mechanical properties and relatively high filtering performance, but also has good barrier properties and radiation resistance. When electron beam radiation sterilization or X-ray sterilization is selected, the dosage is controlled at 16 to 27 kgy, and there is no Escherichia coli colony, bacterial colony, fungal colony, 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, provided by Daqing Chemical Research Center of PetroChina Co., Ltd.;

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

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

[0064] (2) Equipment:

[0065] Kneading and mixing equipment, designed and manufactured by Donghua University;

[0066] Meltblown spinning machine, produced by Tuoren Group;

[0067] X-ray irradiation equipment, produced by Bruker GmbH of Germany.

[0068] Example 1

[0069] 1) Preparation of polyethylene composite resin:

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

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

[0072] The feeding device of the first spunbonded polyethylene nonwoven fabric 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 spunbonded polyethylene nonwoven fabric (such as Figure 1 As shown). Among them, the feeding speed of the first spunbonded polyethylene non-woven fabric is 30m / min, the temperature of the meltblown component is 200℃, the hot air temperature is set to 260℃, the hot air frequency is set to 45Hz, and the receiving distance is 25cm. After the above operation, a double-layer nonwoven material with the first spunbonded non-woven fabric as the bottom layer and the meltblown non-woven fabric as the load layer is obtained. The gram weight ratio of the first spunbonded layer and the meltblown layer is controlled to be 3-10:90-97, as shown Figure 2 shown.

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

[0074] The double-layer nonwoven material obtained in the above steps is then compounded with a second spunbonded polyethylene nonwoven fabric, and then pressed by a hot roller to obtain a polyethylene nonwoven material. The polyethylene nonwoven material is prepared into protective clothing, and the transverse and longitudinal breaking strength of the protective clothing reaches 85N, and the moisture permeability is ﹥8200g / (m 2 ·d), water pressure resistance>11kPa, blood resistance>3. After 16kgy electron beam radiation sterilization, the performance of the protective clothing is not attenuated.

[0075] Example 2

[0076] 1) Preparation of polyethylene composite resin:

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

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

[0079] A feeding device for spunbonded polyethylene nonwoven fabric is added to the rear end of the Tuoren Group meltblown spinning machine, and then the meltblown polyethylene microfibers are collected on the first spunbonded polyethylene nonwoven fabric. Among them, the feeding speed of the first spunbonded polyethylene nonwoven fabric is 20m / min, the temperature of the meltblown component is 210℃, the hot air temperature is set to 250℃, the hot air frequency is set to 45Hz, and the receiving distance is 25cm. After the above operation, a double-layer nonwoven material with the first spunbonded nonwoven fabric as the bottom layer and the meltblown nonwoven fabric as the load layer is obtained, and the gram weight ratio of the first spunbonded layer and the meltblown layer is controlled to be 3-10:90-97.

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

[0081] The double-layer nonwoven material obtained in the above steps is then compounded with a second spunbonded polyethylene nonwoven fabric, and then pressed by a hot roller to obtain a polyethylene nonwoven material. The polyethylene nonwoven material is prepared into protective clothing, and the transverse and longitudinal breaking strength of the protective clothing reaches 93N, and the moisture permeability is ﹥8000g / (m 2 ·d), water pressure resistance>13kPa, blood resistance>3. After 27kgy X-ray sterilization, the performance of the protective clothing is not attenuated.

[0082] Example 3

[0083] 1) Preparation of polyethylene composite resin:

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

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

[0086] The feeding device of spunbond polyethylene non-woven fabric is added to the rear end of the Tuoren Group meltblown spinning machine, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene non-woven fabric. Among them, the feeding speed of the first spunbond polyethylene non-woven fabric is 30m / min, the temperature of the meltblown component is 220℃, the hot air temperature is set to 250℃, the hot air frequency is set to 45Hz, and the receiving distance is 30cm. After the above operation, a double-layer non-woven material with the first spunbond non-woven fabric as the bottom layer and the meltblown non-woven fabric as the load layer is obtained, and the gram weight ratio of the first spunbond layer and the meltblown layer is controlled to be 3-10:90-97.

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

[0088] The double-layer nonwoven material obtained in the above steps is then compounded with a second spunbonded polyethylene nonwoven fabric, and then pressed by a hot roller to obtain a polyethylene nonwoven material. The polyethylene nonwoven material is prepared into protective clothing, and the transverse and longitudinal breaking strength of the protective clothing reaches 87N, and the moisture permeability is ﹥8500g / (m 2 ·d), water pressure resistance>11kPa, blood resistance>3. After 25kgy X-ray sterilization, the performance of the protective clothing is not attenuated.

[0089] Example 4

[0090] 1) Preparation of polyethylene composite resin:

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

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

[0093] The feeding device of spunbond polyethylene non-woven fabric is added to the rear end of the Tuoren Group meltblown spinning machine, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene non-woven fabric. Among them, the feeding speed of the first spunbond polyethylene non-woven fabric is 50m / min, the temperature of the meltblown component is 240℃, the hot air temperature is set to 230℃, the hot air frequency is set to 45Hz, and the receiving distance is 30cm. After the above operation, a double-layer non-woven material with the first spunbond non-woven fabric as the bottom layer and the meltblown non-woven fabric as the load layer is obtained, and the gram weight ratio of the first spunbond layer and the meltblown layer is controlled to be 3-10:90-97.

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

[0095] The double-layer nonwoven material obtained in the above steps is then compounded with a second spunbonded polyethylene nonwoven fabric, and then pressed by a hot roller to obtain a polyethylene nonwoven material. The polyethylene nonwoven material is prepared into protective clothing, and the transverse and longitudinal breaking strength of the protective clothing reaches 89N, and the moisture permeability is ﹥8300g / (m 2 ·d), water pressure resistance>12kPa, blood resistance>3. After electron beam radiation sterilization, the performance of the protective clothing is not attenuated.

[0096] Example 5

[0097] 1) Preparation of polyethylene composite resin:

[0098] 5kg of polyethylene powder with a melt index of 400g / 10min, 95kg of polyethylene powder with a melt index of 1100g / 10min, 0.01kg of diisopropylbenzene peroxide, and 0.15kg of 4,4'-thiobis(6-tert-butyl-3-methylphenol) were fully mechanically premixed, and then added into a twin screw for reactive extrusion to obtain a composite resin. The screw feed section to the homogenizing section were set at a temperature of 110-140°C, and the screw speed was 100rpm.

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

[0100] The feeding device of spunbond polyethylene non-woven fabric is added to the rear end of the Tuoren Group meltblown spinning machine, and then the meltblown polyethylene microfibers are collected on the first spunbond polyethylene non-woven fabric. Among them, the feeding speed of the first spunbond polyethylene non-woven fabric is 50m / min, the temperature of the meltblown component is 240℃, the hot air temperature is set to 230℃, the hot air frequency is set to 45Hz, and the receiving distance is 30cm. After the above operation, a double-layer non-woven material with the first spunbond non-woven fabric as the bottom layer and the meltblown non-woven fabric as the load layer is obtained, and the gram weight ratio of the first spunbond layer and the meltblown layer is controlled to be 3-10:90-97.

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

[0102] The double-layer nonwoven material obtained in the above steps is then compounded with a second spunbonded polyethylene nonwoven fabric, and then pressed by a hot roller to obtain a polyethylene nonwoven material. The polyethylene nonwoven material is prepared into protective clothing, and the transverse and longitudinal breaking strength of the protective clothing reaches 86N, and the moisture permeability is ﹥8400g / (m 2 ·d), water pressure resistance>12kPa, blood resistance>3. After electron beam radiation sterilization, the performance of the protective clothing is not attenuated.

[0103] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A polyethylene nonwoven material, characterized in that: The invention comprises 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, the melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are both 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.

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

4. The polyethylene nonwoven material according to claim 1, characterized in that A spinning aid is also added to the meltblown layer, and 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 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 breaking strength of ≥80N and a moisture permeability of ≥8000g / (m 2 ·d), water pressure resistance>10kPa, blood resistance>3 levels.

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 the preparation method comprises: Step 1, mixing and granulating the first high melt index polyethylene and the second high melt index polyethylene; Step 2, melt-blowing the resin obtained in step 1 to form a melt-blown layer on the first spunbond layer; Step 3: Compounding 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.

7. The method for preparing the polyethylene nonwoven material according to claim 6, characterized in that: The melt indexes of the first high melt index polyethylene and the second high melt index polyethylene are both 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.

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

9. The method for preparing the polyethylene nonwoven material according to claim 6, characterized in that: In step 1, a spinning aid is added during the mixing and granulation of the first high melt index polyethylene and the second high melt index polyethylene, and 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 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.

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

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