A method for manufacturing microfiber nonwoven materials

Abstract

This invention discloses a method for manufacturing ultrafine fiber nonwoven materials, belonging to the field of nonwoven material technology. The manufacturing method consists of the following steps: raw material preparation, melt spinning, web formation, primary hydroentangling reinforcement, soaking, secondary hydroentangling reinforcement, rolling and drying, and electret treatment. The raw material preparation consists of the following steps: preparing modified kaolin, preparing chitosan microspheres, preparing polyethylene raw materials, and preparing polyamide raw materials. This invention can improve the strength, adsorption performance, filtration performance, air permeability, and wear resistance of ultrafine fiber nonwoven materials, with low filtration resistance, a simple production process, low energy and water consumption, and the prepared ultrafine fiber nonwoven materials are not easily deformed at high temperatures.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-woven materials, and particularly relates to a manufacturing method of superfine fiber non-woven material. BACKGROUND

[0002] There is no unified regulation for superfine fibers internationally, and the textile industry in China defines the fiber with a single filament fineness less than 0.44 dtex as a superfine fiber. Most synthetic fibers can be prepared into superfine fibers, such as polyamide, polyester, polyethylene, polypropylene, polyacrylonitrile and the like. Due to the small diameter of the superfine fiber, the fabric is tight, the functionality is improved, the micro-porous effect of geometric characteristics is brought, the fabric has filtering and moisture-permeable waterproof functions, and the strength is high, the specific surface area is large, and thus the adsorption performance is improved, therefore, more and more enterprises choose superfine fibers as raw materials of non-woven materials.

[0003] At present, the preparation methods of superfine fiber non-woven materials mainly include melt-blowing method, island-in-sea type superfine fiber non-woven method and orange-segment type spun-bonded hydroentangled superfine fiber non-woven method. In the melt-blowing method, the fiber diameter can reach 1-5 microns, the structure is loose, the anti-wrinkle ability is good, and the unique capillary structure is provided, so that the melt-blown fabric has good filtering, shielding, heat-insulating and oil-absorbing properties, and can be used as a filter material for air and liquid filtration, and can also be used in the fields of isolation materials, mask materials, thermal insulation materials and oil-absorbing materials, etc., but the fiber orientation degree and crystallinity prepared by the melt-blowing method are low, resulting in low strength of the finished fiber, so that the superfine fiber non-woven material manufactured thereby is difficult to be directly used as a filter material alone, and needs to be combined with a base cloth for strength support. In the island-in-sea type superfine fiber non-woven method, the fiber has many voids, has strong dust absorption and decontamination properties, good adsorption performance and high filtering efficiency, and is fine and soft, but the fiber is easily deformed at high temperature, and has poor wear resistance, so that the superfine fiber non-woven material manufactured thereby is easily deformed at high temperature, has poor wear resistance, and impurities such as sizing agent and oil agent need to be added in the spinning, and the impurities need to be removed from the fiber by using lye, resulting in a complex production process; in the orange-segment type spun-bonded hydroentangled superfine fiber non-woven method, the orange-segment type fiber needs to be opened by a hydroentangling process after the composite spinning and webbing, and due to the strong interfacial bonding force between the two polymer components, the opening is difficult, a large amount of energy and water resources are consumed, and the production cost is high; in addition, when the manufactured superfine fiber non-woven material is used as a filter material, due to the uneven cracking of the fiber, the filtering efficiency and air permeability of the prepared filter material are poor, and the filtering resistance is large.

[0004] Chinese patent CN105671791A discloses a manufacturing method of a two-component superfine non-woven filter material, any two of polyester, polyamide and polyethylene are used as raw materials for composite spinning, the pressure in the air flow drafting process is controlled to obtain a spunbond fiber web with a large difference in fiber linear density, and the two fiber webs are laid to form a final superfine fiber non-woven filter material through multi-pass water jet opening and consolidation.

[0005] Chinese patent CN105671791A discloses a manufacturing method of a two-component superfine non-woven filter material, any two of polyester, polyamide and polyethylene are used as raw materials for composite spinning, the pressure in the air flow drafting process is controlled to obtain a spunbond fiber web with a large difference in fiber linear density, and the two fiber webs are laid to form a final superfine fiber non-woven filter material through multi-pass water jet opening and consolidation.

[0006] Chinese patent CN205130539U discloses an orange segment type split fiber surface layer polyester spunlace filter felt, which is a multi-orange segment type superfine fiber surface layer spunlace composite on the surface of a polyester pre-needled felt layer, mainly applied to flue gas filtration, and can capture PM2.5 particles through gradient filtration, but only relies on the simple pore size of the filter material for physical interception filtration, and has poor adsorption performance for fine dust and other particulate matters such as PM0.3 particles. SUMMARY

[0007] In view of the above technical problems, the present application provides a manufacturing method of a superfine fiber non-woven material, which can improve the strength, adsorption performance, filtration performance, air permeability and wear resistance of the superfine fiber non-woven material, has small filtration resistance, simple production process, low energy and water consumption, and the prepared superfine fiber non-woven material is not easy to deform at high temperature.

[0008] To solve the above technical problems, the technical solutions adopted by the present application are as follows:

[0009] A manufacturing method of a superfine fiber non-woven material, comprising the following steps: raw material preparation, melt spinning, web formation, first water jet reinforcement, soaking, second water jet reinforcement, calendering and drying, and electret treatment.

[0010] The raw material preparation consists of the following steps: preparing modified kaolin, preparing chitosan microspheres, preparing polyethylene raw material, and preparing polyamide raw material;

[0011] The modified kaolin is prepared by mixing kaolin, vinyl triethoxysilane, anhydrous ethanol, and deionized water, then performing ultrasonic oscillation, controlling the frequency of ultrasonic oscillation to be 30-35 kHz and the time to be 30-40 min, transferring to a reaction container with a condensing device after ultrasonic oscillation, controlling the temperature of the reaction container to be 70-75℃, controlling the stirring speed to be 100-300 rpm, stirring and refluxing for 4-5 h, centrifuging, controlling the centrifugal speed to be 6000-7000 rpm and the time to be 6-7 min, washing the precipitate with anhydrous ethanol for 3-4 times, and drying at 90-100℃ to obtain pre-modified kaolin; taking the pre-modified kaolin and toluene and adding them into a reaction container, sealing the reaction container, replacing the air in the reaction container with nitrogen, controlling the temperature of the reaction container to be 70-80℃, controlling the stirring speed to be 100-300 rpm, adding azobisisobutyronitrile and dimethyl diallyl ammonium chloride, stirring for 7-8 h, centrifuging, controlling the centrifugal speed to be 6000-7000 rpm and the time to be 6-7 min, washing the precipitate with anhydrous ethanol for 3-4 times, and drying at 90-100℃ to obtain modified kaolin;

[0012] In the preparation of modified kaolin, the mass ratio of kaolin, vinyl triethoxysilane, anhydrous ethanol, and deionized water is 100-110:5-6:350-450:350-450;

[0013] The mass ratio of pre-modified kaolin, toluene, azobisisobutyronitrile, and dimethyl diallyl ammonium chloride is 10-11:450-500:0.07-0.08:5-5.5;

[0014] The particle size of the kaolin is 100 nm;

[0015] The chitosan microspheres are prepared by adding chitosan, 2-hydroxyethyl acrylate, acrylic acid, and deionized water into a reaction container, sealing the reaction container, replacing the air in the reaction container with nitrogen, controlling the temperature of the reaction container to be 80-90℃, controlling the stirring speed to be 100-300 rpm, stirring for 30-40 min, adding potassium persulfate, continuing to stir for 2-2.5 h, adding glutaraldehyde, continuing to stir for 30-40 min, centrifuging, controlling the centrifugal speed to be 9000-10000 rpm and the time to be 10-15 min, washing the filter residue with deionized water for 3-5 times after centrifugation, and drying at 110-120℃ to obtain chitosan microspheres;

[0016] The mass ratio of the prepared chitosan microspheres, chitosan, 2-hydroxyethyl acrylate, acrylic acid, deionized water, potassium persulfate and glutaraldehyde is 3-3.2:1.6-1.7:1.5-2:250-300:0.5-0.6:1-1.2;

[0017] The molecular weight of the chitosan is 100,000, and the degree of deacetylation is 90%;

[0018] The particle size of the chitosan microspheres is 220-290nm;

[0019] The preparation of polyethylene raw material, high density polyethylene, modified kaolin, chitosan microspheres are added into the mixer according to the weight ratio of 60-65:1:0.7-0.8, and the polyethylene raw material is obtained after mixing uniformly;

[0020] The melt index of the high density polyethylene is 0.7g / 10min, and the density is 0.943g / cm 3 ;

[0021] The preparation of polyamide raw material, polyamide 6, modified kaolin, chitosan microspheres are added into the mixer according to the weight ratio of 90-100:1:1.3-1.4, and the polyamide raw material is obtained after mixing uniformly;

[0022] The melting point of the polyamide 6 is 220℃, and the density is 1.14g / cm 3 ;

[0023] The melt spinning, the polyethylene raw material and the polyamide raw material are respectively introduced into two sets of screw extruders according to the mass ratio of 75:25, the extrusion temperature of the screw extruder corresponding to the polyethylene raw material is controlled at 190-200℃, the extrusion temperature of the screw extruder corresponding to the polyamide raw material is controlled at 255-265℃, then the melt is filtered through a melt filter, and then the two polymer melts are introduced into the same spinneret hole of an orange segment type spinneret, the orange segment type spinneret divides the filaments into eight segments, the diameter of the spinneret hole is 0.3mm, and after extrusion, cooling, oiling, drawing, winding, heat setting and cutting, an orange segment type composite fiber is obtained;

[0024] The fineness of the orange segment type composite fiber is 2-2.4dtex, and the length is 50-60mm;

[0025] The webbing, the orange segment type composite fiber is opened, carded and laid, and a web is obtained;

[0026] The once water jet reinforcement is performed on the fiber web by a water jet machine to obtain the once water jet reinforced fiber web; the once water jet reinforcement is divided into three passes, the water needle pressure of the first pass water jet reinforcement is 3-4 MPa, the water needle aperture is 0.1 mm, and the water needle acting distance is 11-12 mm; the water needle pressure of the second pass water jet reinforcement is 6-7 MPa, the water needle aperture is 0.1 mm, and the water needle acting distance is 11-12 mm; the water needle pressure of the third pass water jet reinforcement is 9-10 MPa, the water needle aperture is 0.13 mm, and the water needle acting distance is 11-12 mm;

[0027] The once water jet reinforced fiber is completely soaked in the soaking liquid at room temperature for 30-50 min to obtain the soaked fiber web;

[0028] The soaking liquid is a cationic polyacrylamide aqueous solution, wherein the molecular weight of the cationic polyacrylamide is 8 million, the ionicity is 30 wt.%, and the mass concentration is 0.01%;

[0029] The twice water jet reinforcement is performed on the soaked fiber web by a water jet machine to obtain the twice water jet reinforced fiber web; the twice water jet reinforcement is divided into three passes, the water needle pressure of the first pass water jet reinforcement is 14-15 MPa, the water needle aperture is 0.13 mm, and the water needle acting distance is 13-14 mm; the water needle pressure of the second pass water jet reinforcement is 16-17 MPa, the water needle aperture is 0.16 mm, and the water needle acting distance is 13-14 mm; the water needle pressure of the third pass water jet reinforcement is 19-20 MPa, the water needle aperture is 0.16 mm, and the water needle acting distance is 11-12 mm;

[0030] The twice water jet reinforced fiber web is rolled and dried to obtain the dried fiber web; the linear pressure during rolling is controlled to be 130-140 N / cm, and the temperature during drying is controlled to be 140-150 DEG C;

[0031] The dried fiber web is subjected to an electret treatment, and then is wound to obtain the ultrafine fiber non-woven material; the electret voltage in the electret treatment is controlled to be 20-30 kV, the electret distance is controlled to be 5-10 cm, and the electret time is controlled to be 20-30 s.

[0032] Compared with the prior art, the method has the following beneficial effects:

[0033] (1) The method for manufacturing the ultrafine fiber non-woven material can improve the strength of the ultrafine fiber non-woven material, and the transverse breaking strength of the ultrafine fiber non-woven cloth manufactured by the method is 132.4-146.2 N / 5 cm, and the longitudinal breaking strength is 171.5-187.6 N / 5 cm;

[0034] (2) The manufacturing method of the superfine fiber non-woven material can improve the adsorption performance and filtration performance of the superfine fiber non-woven material, and reduce the filtration resistance, the filtration efficiency of PM2.5 of the superfine fiber non-woven fabric manufactured by the method is 98.7-99.4%, the filtration efficiency of the sodium chloride aerosol with an air flow of 32 L / min and an air dynamic median diameter of 0.26 μm is 94.1-95.5%, and the filtration resistance is 108.7-113.6 Pa;

[0035] (3) The manufacturing method of the superfine fiber non-woven material can improve the air permeability of the superfine fiber non-woven material, and the air permeability of the superfine fiber non-woven fabric prepared by the method is 17397-18608 mL / (cm 2 ·h);

[0036] (4) The manufacturing method of the superfine fiber non-woven material can improve the wear resistance of the superfine fiber non-woven material, the wear resistance test of the superfine fiber non-woven fabric prepared by the method is carried out by using a Martindale wear tester, the dynamic range is 60 mm, the outer wheel speed is 50 rpm, a 6N pressure weight is used during the test, and the friction frequency when damage occurs is 29457-32615;

[0037] (5) The manufacturing method of the superfine fiber non-woven material can ensure that the prepared superfine fiber non-woven material is not easy to deform at high temperature, the superfine fiber non-woven material prepared by the method is placed in an environment with a temperature of 80℃ for 10 days, the transverse size change rate is 0.6-1.0%, and the longitudinal size change rate is 0.3-0.6%;

[0038] (6) The manufacturing method of the superfine fiber non-woven material does not introduce impurities, and the step of treating the impurities is omitted, so that the production process is simple;

[0039] (7) The manufacturing method of the superfine fiber non-woven material is simple, the opening rate of the fiber can be increased to 97-98% according to the manufacturing method, so that the use of excessive energy and water is avoided, and the consumption of energy and water is reduced. DETAILED DESCRIPTION

[0040] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described.

[0041] Example 1

[0042] A manufacturing method of a superfine fiber non-woven material, specifically:

[0043] 1. Raw material preparation:

[0044] (1) Preparation of modified kaolin: 100 g of kaolin, 5 g of vinyl triethoxysilane, 350 g of anhydrous ethanol, 350 g of deionized water were mixed and ultrasonic oscillation was carried out, the frequency of ultrasonic oscillation was controlled at 30 kHz, the time was 30 min, after ultrasonic oscillation was completed, it was transferred to a reaction container with a condensing device, the temperature of the reaction container was controlled to 70℃, the stirring speed was controlled to 100 rpm, stirring reflux was carried out for 4 h, centrifugation was carried out, the centrifugal speed was controlled to 6000 rpm, the time was 7 min, the precipitate was washed with anhydrous ethanol for 3 times, and was dried at 90℃ to obtain a pre-modified kaolin; 10 g of the pre-modified kaolin, 450 g of toluene were added into a reaction container, the reaction container was sealed, nitrogen was introduced to replace the air in the reaction container, the temperature of the reaction container was controlled to 70℃, the stirring speed was controlled to 100 rpm, 0.07 g of azobisisobutyronitrile and 5 g of dimethyl diallyl ammonium chloride were added, stirring was carried out for 7 h, centrifugation was carried out, the centrifugal speed was controlled to 6000 rpm, the time was 7 min, the precipitate was washed with anhydrous ethanol for 3 times, and was dried at 90℃ to obtain a modified kaolin;

[0045] The particle size of the kaolin is 100 nm;

[0046] (2) Preparation of chitosan microspheres: 3 g of chitosan, 1.6 g of 2-hydroxyethyl acrylate, 1.5 g of acrylic acid, 250 g of deionized water were added into a reaction container, the reaction container was sealed, the air in the reaction container was replaced with nitrogen, the temperature of the reaction container was controlled to 80℃, the stirring speed was controlled to 100 rpm, stirring was carried out for 30 min, 0.5 g of potassium persulfate was added, stirring was continued for 2 h, 1 g of glutaraldehyde was added, stirring was continued for 30 min, centrifugation was carried out, the centrifugal speed was controlled to 9000 rpm, the time was 15 min, after centrifugation, the filter residue was washed with deionized water for 3 times, and was dried at 110℃ to obtain chitosan microspheres;

[0047] The molecular weight of the chitosan is 100,000, and the degree of deacetylation is 90%;

[0048] The particle size of the chitosan microspheres is 220 nm;

[0049] (3) Preparation of polyethylene raw material: high-density polyethylene, modified kaolin and chitosan microspheres were added into a mixer in a weight ratio of 60:1:0.7 and were uniformly mixed to obtain a polyethylene raw material;

[0050] The melt index of the high-density polyethylene is 0.7 g / 10 min, and the density is 0.943 g / cm 3 ;

[0051] (4) Preparation of polyamide raw material: polyamide 6, modified kaolin and chitosan microspheres were added into a mixer in a weight ratio of 90:1:1.3 and were uniformly mixed to obtain a polyamide raw material;

[0052] The melting point of the polyamide 6 is 220℃, and the density is 1.14g / cm 3 ;

[0053] 2. Melt spinning: the polyethylene raw material and the polyamide raw material are respectively fed into two sets of screw extruders according to a mass ratio of 75:25, the extrusion temperature of the screw extruder corresponding to the polyethylene raw material is controlled at 190℃, the extrusion temperature of the screw extruder corresponding to the polyamide raw material is controlled at 255℃, then the two kinds of polymer melts are filtered by feeding into a melt filter, metered by feeding into a metering pump, and then extruded through the same spinning hole of a segmented orifice spinneret, the segmented orifice spinneret divides the filaments into eight segments, the diameter of the spinning hole is 0.3mm, and after extrusion, the filaments are cooled, oiled, drawn, wound, heat set, and cut to obtain segmented orifice composite fibers;

[0054] The segmented orifice composite fibers have a fineness of 2dtex and a length of 50mm;

[0055] 3. Web formation: the segmented orifice composite fibers are opened, carded, and laid to obtain a web;

[0056] 4. Primary hydroentanglement: the web is fed into a hydroentanglement machine for primary hydroentanglement to obtain a web after primary hydroentanglement; the primary hydroentanglement is divided into three passes, the water needle pressure of the first pass of hydroentanglement is 3MPa, the water needle diameter is 0.1mm, and the water needle action distance is 11mm; the water needle pressure of the second pass of hydroentanglement is 6MPa, the water needle diameter is 0.1mm, and the water needle action distance is 11mm; the water needle pressure of the third pass of hydroentanglement is 9MPa, the water needle diameter is 0.13mm, and the water needle action distance is 11mm;

[0057] 5. Soaking: the web after primary hydroentanglement is completely soaked in a soaking solution, and soaked at room temperature for 30min to obtain a web after soaking;

[0058] The soaking solution is a cationic polyacrylamide aqueous solution, wherein the molecular weight of the cationic polyacrylamide is 8 million, the ionicity is 30wt.%, and the mass concentration is 0.01%;

[0059] 6. Secondary hydroentanglement: the web after soaking is fed into a hydroentanglement machine for secondary hydroentanglement to obtain a web after secondary hydroentanglement; the secondary hydroentanglement is divided into three passes, the water needle pressure of the first pass of hydroentanglement is 14MPa, the water needle diameter is 0.13mm, and the water needle action distance is 13mm; the water needle pressure of the second pass of hydroentanglement is 16MPa, the water needle diameter is 0.16mm, and the water needle action distance is 13mm; the water needle pressure of the third pass of hydroentanglement is 19MPa, the water needle diameter is 0.16mm, and the water needle action distance is 11mm;

[0060] 7. Calender drying: the secondary water jet reinforced web is subjected to calendering, the linear pressure during calendering is controlled to be 130 N / cm, and then drying is performed, the temperature during drying is controlled to be 140℃, to obtain a dried web;

[0061] 8. Electrification: the dried web is subjected to electrification treatment, and then is wound up, to obtain the superfine fiber nonwoven material; the electrification voltage in the electrification treatment is controlled to be 20 kV, the electrification distance is controlled to be 5 cm, and the electrification time is controlled to be 20 s.

[0062] The superfine fiber nonwoven material has a grammage of 55 gsm.

[0063] Example 2

[0064] A method for manufacturing a superfine fiber nonwoven material, specifically:

[0065] 1. Raw material preparation:

[0066] (1) Preparation of modified kaolin: 105 g of kaolin, 5.5 g of vinyltriethoxysilane, 400 g of anhydrous ethanol, and 400 g of deionized water are mixed and subjected to ultrasonic oscillation, the frequency of the ultrasonic oscillation is controlled to be 32 kHz, and the time is controlled to be 35 min, after the ultrasonic oscillation is completed, the reaction container is transferred to a reaction container with a condenser device, the temperature of the reaction container is controlled to be 72℃, the stirring speed is controlled to be 200 rpm, stirring and refluxing are performed for 4.5 h, centrifugation is performed, the centrifugation speed is controlled to be 6500 rpm, and the time is controlled to be 6.5 min, the precipitate is washed with anhydrous ethanol for 3 times, and is dried at 95℃, to obtain a pre-modified kaolin; 10.5 g of the pre-modified kaolin and 480 g of toluene are added to a reaction container, the reaction container is sealed, nitrogen gas is introduced to replace the air in the reaction container, the temperature of the reaction container is controlled to be 75℃, the stirring speed is controlled to be 200 rpm, 0.07 g of azobisisobutyronitrile and 5.2 g of dimethyldiallylammonium chloride are added, stirring is performed for 7.5 h, centrifugation is performed, the centrifugation speed is controlled to be 6500 rpm, and the time is controlled to be 6.5 min, the precipitate is washed with anhydrous ethanol for 3 times, and is dried at 95℃, to obtain the modified kaolin;

[0067] The particle size of the kaolin is 100 nm;

[0068] (2) Preparation of chitosan microspheres: 3.1 g of chitosan, 1.6 g of 2-hydroxyethyl acrylate, 1.8 g of acrylic acid, and 280 g of deionized water were added to a reaction container, the reaction container was closed, the air in the reaction container was replaced with nitrogen, the temperature of the reaction container was controlled to 85°C, the stirring speed was controlled to 200 rpm, stirring was performed for 35 min, 0.5 g of potassium persulfate was added, stirring was continued for 2.2 h, 1.1 g of glutaraldehyde was added, stirring was continued for 35 min, centrifugation was performed at a speed of 9500 rpm for 12 min, the centrifuged residue was washed with deionized water 4 times, and the residue was dried at 115°C to obtain chitosan microspheres;

[0069] The chitosan has a molecular weight of 100,000 and a degree of deacetylation of 90%;

[0070] The chitosan microspheres have a particle size of 250 nm;

[0071] (3) Preparation of polyethylene raw material: high-density polyethylene, modified kaolin, and chitosan microspheres were added to a mixer in a weight ratio of 62:1:0.7 and uniformly mixed to obtain a polyethylene raw material;

[0072] The high-density polyethylene has a melt index of 0.7 g / 10 min and a density of 0.943 g / cm 3 ;

[0073] (4) Preparation of polyamide raw material: polyamide 6, modified kaolin, and chitosan microspheres were added to a mixer in a weight ratio of 95:1:1.3 and uniformly mixed to obtain a polyamide raw material;

[0074] The polyamide 6 has a melting point of 220°C and a density of 1.14 g / cm 3 ;

[0075] 2. Melt spinning: the polyethylene raw material and the polyamide raw material were respectively fed into two sets of screw extruders in a mass ratio of 75:25, the extrusion temperature of the screw extruder corresponding to the polyethylene raw material was controlled to 195°C, the extrusion temperature of the screw extruder corresponding to the polyamide raw material was controlled to 260°C, then the two polymer melts were filtered through a melt filter, metered through a metering pump, and then extruded through the same jet hole of a segmented orange-type spinneret, the segmented orange-type spinneret divided the filaments into eight segments, the jet hole had a diameter of 0.3 mm, and after extrusion, the filaments were cooled, oiled, drawn, wound, heat set, and cut to obtain segmented orange-type composite fibers;

[0076] The segmented orange-type composite fibers have a fineness of 2.2 dtex and a length of 55 mm;

[0077] 3. Webbing: the segmented orange-type composite fibers were opened, carded, and laid to obtain a web;

[0078] 4. First water jet reinforcement: the fiber web is sent to a water jet machine for first water jet reinforcement to obtain the fiber web after first water jet reinforcement; the first water jet reinforcement is divided into three passes, the water needle pressure of the first pass of water jet reinforcement is 3.5 MPa, the water needle aperture is 0.1 mm, and the water needle action distance is 11.5 mm; the water needle pressure of the second pass of water jet reinforcement is 6.5 MPa, the water needle aperture is 0.1 mm, and the water needle action distance is 11.5 mm; the water needle pressure of the third pass of water jet reinforcement is 9.5 MPa, the water needle aperture is 0.13 mm, and the water needle action distance is 11.5 mm;

[0079] 5. Soaking: the fiber after first water jet reinforcement is completely soaked in a soaking solution, and soaked at room temperature for 40 min to obtain the fiber web after soaking;

[0080] The soaking solution is a cationic polyacrylamide aqueous solution, wherein the molecular weight of the cationic polyacrylamide is 8 million, the ionicity is 30 wt.%, and the mass concentration is 0.01%;

[0081] 6. Second water jet reinforcement: the fiber web after soaking is sent to a water jet machine for second water jet reinforcement to obtain the fiber web after second water jet reinforcement; the second water jet reinforcement is divided into three passes, the water needle pressure of the first pass of water jet reinforcement is 14.5 MPa, the water needle aperture is 0.13 mm, and the water needle action distance is 13.5 mm; the water needle pressure of the second pass of water jet reinforcement is 16.5 MPa, the water needle aperture is 0.16 mm, and the water needle action distance is 13.5 mm; the water needle pressure of the third pass of water jet reinforcement is 19.5 MPa, the water needle aperture is 0.16 mm, and the water needle action distance is 11.5 mm;

[0082] 7. Calendering and drying: the fiber web after second water jet reinforcement is subjected to calendering, the linear pressure during calendering is controlled to be 135 N / cm, and then drying is performed, the temperature during drying is controlled to be 145°C to obtain the fiber web after drying;

[0083] 8. Electrification: the fiber web after drying is subjected to electrification treatment, and then wound to obtain the ultrafine fiber nonwoven material; the electrification voltage during electrification treatment is controlled to be 25 kV, the electrification distance is 8 cm, and the electrification time is 25 s.

[0084] The grammage of the ultrafine fiber nonwoven material is 59 gsm.

[0085] Example 3

[0086] A manufacturing method of an ultrafine fiber nonwoven material, specifically:

[0087] 1. Raw material preparation:

[0088] (1) Preparation of modified kaolin: 110 g of kaolin, 6 g of vinyl triethoxysilane, 450 g of anhydrous ethanol, 450 g of deionized water were mixed and ultrasonic oscillation was carried out, the frequency of ultrasonic oscillation was controlled at 35 kHz, the time was 40 min, after ultrasonic oscillation was completed, it was transferred to a reaction container with a condensing device, the temperature of the reaction container was controlled to 75℃, the stirring speed was controlled to 300 rpm, stirring reflux was carried out for 5 h, centrifugation was carried out, the centrifugal speed was controlled at 7000 rpm, the time was 6 min, the precipitate was washed with anhydrous ethanol for 4 times, and was dried at 100℃ to obtain a pre-modified kaolin; 11 g of the pre-modified kaolin, 500 g of toluene were added into a reaction container, the reaction container was sealed, nitrogen was introduced to replace the air in the reaction container, the temperature of the reaction container was controlled to 80℃, the stirring speed was controlled to 300 rpm, 0.08 g of azobisisobutyronitrile and 5.5 g of dimethyldiallylammonium chloride were added, stirring was carried out for 8 h, centrifugation was carried out, the centrifugal speed was controlled at 7000 rpm, the time was 6 min, the precipitate was washed with anhydrous ethanol for 4 times, and was dried at 100℃ to obtain a modified kaolin;

[0089] The particle size of the kaolin is 100 nm;

[0090] (2) Preparation of chitosan microspheres: 3.2 g of chitosan, 1.7 g of 2-hydroxyethyl acrylate, 2 g of acrylic acid, 300 g of deionized water were added into a reaction container, the reaction container was sealed, the air in the reaction container was replaced with nitrogen, the temperature of the reaction container was controlled to 90℃, the stirring speed was controlled to 300 rpm, stirring was carried out for 40 min, 0.6 g of potassium persulfate was added, stirring was continued for 2.5 h, 1.2 g of glutaraldehyde was added, stirring was continued for 40 min, centrifugation was carried out, the centrifugal speed was controlled at 10000 rpm, the time was 10 min, after centrifugation, the filter residue was washed with deionized water for 5 times, and was dried at 120℃ to obtain chitosan microspheres;

[0091] The molecular weight of the chitosan is 100,000, and the degree of deacetylation is 90%;

[0092] The particle size of the chitosan microspheres is 290 nm;

[0093] (3) Preparation of polyethylene raw material: high-density polyethylene, modified kaolin, chitosan microspheres were added into a mixer in a weight ratio of 65:1:0.8 and were uniformly mixed to obtain a polyethylene raw material;

[0094] The melt index of the high-density polyethylene is 0.7 g / 10 min, and the density is 0.943 g / cm 3 ;

[0095] (4) Preparing the polyamide raw material: adding polyamide 6, modified kaolin, and chitosan microspheres into a mixer according to a weight ratio of 100:1:1.4, and uniformly mixing to obtain a polyamide raw material;

[0096] The melting point of the polyamide 6 is 220°C, and the density is 1.14 g / cm 3 ;

[0097] 2. Melt spinning: passing the polyethylene raw material and the polyamide raw material into two sets of screw extruders according to a mass ratio of 75:25, controlling the extrusion temperature of the screw extruder corresponding to the polyethylene raw material to be 200°C, and the extrusion temperature of the screw extruder corresponding to the polyamide raw material to be 265°C, then filtering in a melt filter, metering in a metering pump, and then extruding the two polymer melts into the same jet hole of a segmented-pie-shaped spinneret, the segmented-pie-shaped spinneret divides the filaments into eight segments, the jet hole has a diameter of 0.3 mm, and after extrusion, cooling, oiling, drafting, winding, heat setting, and cutting, a segmented-pie-shaped composite fiber is obtained;

[0098] The segmented-pie-shaped composite fiber has a fineness of 2.4 dtex and a length of 60 mm;

[0099] 3. Forming a web: opening, carding, and laying the segmented-pie-shaped composite fiber to obtain a web;

[0100] 4. Primary hydroentanglement reinforcement: passing the web into a hydroentanglement machine for primary hydroentanglement reinforcement to obtain a web after primary hydroentanglement reinforcement; the primary hydroentanglement reinforcement is divided into three passes, the first pass of hydroentanglement reinforcement has a water needle pressure of 4 MPa, a water needle hole diameter of 0.1 mm, and a water needle action distance of 12 mm; the second pass of hydroentanglement reinforcement has a water needle pressure of 7 MPa, a water needle hole diameter of 0.1 mm, and a water needle action distance of 12 mm; and the third pass of hydroentanglement reinforcement has a water needle pressure of 10 MPa, a water needle hole diameter of 0.13 mm, and a water needle action distance of 12 mm;

[0101] 5. Soaking: completely soaking the web after primary hydroentanglement reinforcement in a soaking solution at room temperature for 50 min to obtain a web after soaking;

[0102] The soaking solution is a cationic polyacrylamide aqueous solution, wherein the molecular weight of the cationic polyacrylamide is 8 million, the ionicity is 30 wt.%, and the mass concentration is 0.01%;

[0103] 6. Secondary water jet reinforcement: the soaked web is passed into a water jet machine for secondary water jet reinforcement to obtain a secondary water jet reinforced web; the secondary water jet reinforcement is divided into three passes, the first pass of water jet reinforcement has a water jet pressure of 15 MPa, a water jet aperture of 0.13 mm, and a water jet acting distance of 14 mm; the second pass of water jet reinforcement has a water jet pressure of 17 MPa, a water jet aperture of 0.16 mm, and a water jet acting distance of 14 mm; the third pass of water jet reinforcement has a water jet pressure of 20 MPa, a water jet aperture of 0.16 mm, and a water jet acting distance of 12 mm;

[0104] 7. Calendering and drying: the secondary water jet reinforced web is subjected to calendering to control the linear pressure at 140 N / cm, and then drying at a temperature of 150°C to obtain a dried web;

[0105] 8. Electrification: the dried web is subjected to electrification treatment, and then wound up to obtain the superfine fiber nonwoven material; the electrification voltage in the electrification treatment is controlled at 30 kV, the electrification distance is 10 cm, and the electrification time is 30 s.

[0106] The superfine fiber nonwoven material has a grammage of 63 gsm.

[0107] Comparative Example 1

[0108] The manufacturing method of the superfine fiber nonwoven material described in Example 2 is adopted, except that in the first step of raw material preparation, the first step of preparing modified kaolin is omitted, and in the third step of preparing polyethylene raw material and the fourth step of preparing polyamide raw material, kaolin with a particle size of 100 nm is used instead of the modified kaolin in an equal amount, and the fifth step of soaking is omitted.

[0109] Comparative Example 2

[0110] The manufacturing method of the superfine fiber nonwoven material described in Example 2 is adopted, except that in the first step of raw material preparation, the second step of preparing chitosan microspheres is omitted, and in the third step of preparing polyethylene raw material and the fourth step of preparing polyamide raw material, the addition of chitosan microspheres is omitted.

[0111] Test Example 1

[0112] The transverse breaking strength, longitudinal breaking strength, PM2.5 filtration efficiency, and air permeability of the superfine fiber nonwoven fabrics prepared in Examples 1-3 and Comparative Examples 1-2 are tested, and the fiber opening rate of the secondary water jet reinforced web obtained in the seventh step of calendering and drying in Examples 1-3 and Comparative Examples 1-2 is tested, and the test results are as follows:

[0113]

[0114] Test Example 2

[0115] The ultra-fine fiber nonwoven fabric prepared in Examples 1-3 and Comparative Examples 1-2 was subjected to filtration efficiency and filtration resistance test, specifically, the filtration efficiency and filtration resistance of sodium chloride aerosol with an air dynamic median diameter of 0.26 μm were tested under the condition of an air flow of 32 L / min, and the test results are as follows:

[0116]

[0117] Test Example 3

[0118] The ultra-fine fiber nonwoven fabric prepared in Examples 1-3 and Comparative Examples 1-2 was subjected to abrasion resistance test, specifically, the abrasion resistance of the ultra-fine fiber nonwoven fabric prepared in Examples 1-3 and Comparative Examples 1-2 was tested using a Martindale abrasion tester, the dynamic range was 60 mm, the outer wheel speed was 50 rpm, 6 N pressure weight was used during the test, and the number of abrasions at which breakage occurred was recorded, and the recorded results are as follows:

[0119]

[0120] Test Example 4

[0121] The ultra-fine fiber nonwoven fabric prepared in Examples 1-3 and Comparative Examples 1-2 was subjected to size change rate test at high temperature, specifically, the ultra-fine fiber nonwoven fabric sample was cut into a transverse length of 100 cm and a longitudinal length of 50 cm, and then placed in an environment at a temperature of 80℃ for 10 days, the transverse length and the longitudinal length of the sample were tested, and then the transverse size change rate and the longitudinal size change rate were tested, and the test results are as follows:

[0122]

[0123] As can be seen from the results of Test Examples 1-4, by adding modified kaolin to the ultra-fine fiber and soaking it with cationic polyacrylamide aqueous solution, the strength, adsorption performance, filtration performance, and abrasion resistance of the ultra-fine fiber nonwoven material can be improved, the fiber opening rate of the ultra-fine fiber nonwoven material can be increased, the filtration resistance of the ultra-fine fiber nonwoven material can be reduced, and the size deformation rate of the prepared ultra-fine fiber nonwoven material at high temperature can also be reduced.

[0124] By adding chitosan microspheres to the ultra-fine fiber, the strength, adsorption performance, filtration performance, air permeability, and abrasion resistance of the ultra-fine fiber nonwoven material can be improved, the filtration resistance of the ultra-fine fiber nonwoven material can be reduced, and the size deformation rate of the prepared ultra-fine fiber nonwoven material at high temperature can also be reduced.

[0125] The preparation method of the modified kaolin is that the nanoscale kaolin is modified by a silane coupling agent, specifically, vinyltriethoxysilane is used for grafting to introduce carbon-carbon double bonds on the surface of the nanoscale kaolin, then under the action of an initiator, diallyl ammonium chloride is grafted to introduce polydiallyldimethylammonium chloride on the surface of the nanoscale kaolin, the polydiallyldimethylammonium chloride can improve the compatibility between the nanoscale kaolin and high-density polyethylene and polyamide 6, and is more conducive to the dispersion of the kaolin, thereby improving the strength and wear resistance of the superfine fiber nonwoven material, and also reducing the dimensional deformation rate of the prepared superfine fiber nonwoven material at high temperature; and the polydiallyldimethylammonium chloride can also improve the adsorption of particulate matter, thereby improving the adsorption performance of the superfine fiber nonwoven material; after the first water jet reinforcement, the superfine fiber nonwoven material is soaked in a cationic polyacrylamide aqueous solution, the cationic polyacrylamide aqueous solution can penetrate into the fibers of the two materials by utilizing the repulsion between cations, and is more conducive to the separation of fibers of different materials; the soaking is performed between the first water jet reinforcement and the second water jet reinforcement, which can not only avoid the deformation of the nonwoven material caused by directly soaking in the cationic polyacrylamide aqueous solution, but also can further reinforce the nonwoven material after soaking, so that the fibers of different materials are completely separated, the filtration performance of the superfine fiber nonwoven material is improved, the fiber opening rate of the superfine fiber nonwoven material is improved, and the filtration resistance of the superfine fiber nonwoven material is reduced.

[0126] The preparation method of the chitosan microspheres is that chitosan is polymerized with 2-hydroxyethyl acrylate, and then glutaraldehyde is used for crosslinking to form nanoscale crosslinked microspheres; since the nanoscale crosslinked microspheres have a large specific surface area, after being added into high-density polyethylene and polyamide 6, the porosity of the fibers can be improved, thereby the filtration performance, air permeability and filtration resistance of the superfine fiber nonwoven material can be improved; chitosan can improve the adsorption of particulate matter, thereby improving the adsorption performance of the superfine fiber nonwoven material; in addition, the nanoscale crosslinked microspheres can also improve the density and internal bonding force of the superfine fibers, thereby improving the strength and wear resistance of the superfine fiber nonwoven material, and also ensuring that the prepared superfine fiber nonwoven material is not easy to deform at high temperature.

[0127] Unless otherwise specified, the percentages used in the present application are mass percentages.

[0128] Finally, it should be noted that: the above only describes the preferred embodiments of the present application and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of manufacturing a microfiber nonwoven material, characterized by, It is characterized in that the preparation of raw materials comprises the following steps: preparation of modified kaolin, preparation of chitosan microspheres, preparation of polyethylene raw materials, and preparation of polyamide raw materials. The preparation of raw materials comprises the following steps: preparation of modified kaolin, preparation of chitosan microspheres, preparation of polyethylene raw materials, and preparation of polyamide raw materials. The preparation of modified kaolin comprises the following steps: mixing kaolin, vinyltriethoxysilane, anhydrous ethanol, and deionized water, ultrasonic oscillation, transferring to a reaction container with a condenser, controlling the temperature of the reaction container to 70-75 DEG C, stirring and refluxing, centrifuging, washing and drying the precipitate, obtaining pre-modified kaolin, adding pre-modified kaolin and toluene into the reaction container, replacing the air in the reaction container with nitrogen, controlling the temperature of the reaction container to 70-80 DEG C, stirring, adding azobisisobutyronitrile and dimethyl diallyl ammonium chloride, centrifuging, washing and drying the precipitate, and obtaining modified kaolin. In the preparation of modified kaolin, the mass ratio of kaolin, vinyltriethoxysilane, anhydrous ethanol, and deionized water is 100-110:5-6:350-450:350-450. The mass ratio of pre-modified kaolin, toluene, azobisisobutyronitrile, and dimethyl diallyl ammonium chloride is 10-11:450-500:0.07-0.08:5-5.

5. The preparation of chitosan microspheres comprises the following steps: adding chitosan, 2-hydroxyethyl acrylate, acrylic acid, and deionized water into a reaction container, replacing the air in the reaction container with nitrogen, controlling the temperature of the reaction container to 80-90 DEG C, stirring, adding potassium persulfate, continuing to stir, adding glutaraldehyde, continuing to stir, centrifuging, washing and drying the precipitate, and obtaining chitosan microspheres. In the preparation of chitosan microspheres, the mass ratio of chitosan, 2-hydroxyethyl acrylate, acrylic acid, deionized water, potassium persulfate, and glutaraldehyde is 3-3.2:1.6-1.7:1.5-2:250-300:0.5-0.6:1-1.

2.

2. The method of manufacturing a microfiber nonwoven material according to claim 1, characterized by, In the preparation of modified kaolin, the particle size of the kaolin is 100 nm.

3. The method of manufacturing a microfiber nonwoven material according to claim 1, characterized by, In the preparation of chitosan microspheres, the molecular weight of the chitosan is 100,000, and the degree of deacetylation is 90%.

4. The method of manufacturing a microfiber nonwoven material according to claim 1, characterized by, The preparation of polyethylene raw materials comprises the following steps: adding high-density polyethylene, modified kaolin, and chitosan microspheres into a mixer according to a weight ratio of 60-65:1:0.7-0.8, mixing uniformly, and obtaining polyethylene raw materials.

5. The method of manufacturing a microfiber nonwoven material according to claim 1, characterized in that, The preparation of polyamide raw materials comprises the following steps: adding polyamide 6, modified kaolin, and chitosan microspheres into a mixer according to a weight ratio of 90-100:1:1.3-1.4, mixing uniformly, and obtaining polyamide raw materials.

6. The method of manufacturing a microfiber nonwoven material according to claim 1, characterized in that, The melt spinning, the polyethylene raw material and the polyamide raw material are respectively introduced into two sets of screw extruders according to a mass ratio of 75:25, then filtered in a melt filter, metered in a metering pump, and then extruded into two polymer melts, and then extruded into the same spinneret hole of a segmented pie spinneret, the segmented pie spinneret divides the filaments into eight segments, and after extrusion, cooling, oiling, drawing, winding, heat setting and cutting, the segmented pie composite fiber is obtained; The segmented pie composite fiber has a fineness of 2-2.4 dtex and a length of 50-60 mm. The webbing, the segmented pie composite fiber is opened, carded and laid to obtain a fiber web.

7. The method of manufacturing a microfiber nonwoven material according to claim 1, characterized by, The first water jet reinforcement, the fiber web is introduced into a water jet machine for first water jet reinforcement to obtain a fiber web after first water jet reinforcement; the first water jet reinforcement is divided into three passes, the water needle pressure of the first pass of water jet reinforcement is 3-4 MPa, the water needle aperture is 0.1 mm, and the water needle action distance is 11-12 mm; the water needle pressure of the second pass of water jet reinforcement is 6-7 MPa, the water needle aperture is 0.1 mm, and the water needle action distance is 11-12 mm; the water needle pressure of the third pass of water jet reinforcement is 9-10 MPa, the water needle aperture is 0.13 mm, and the water needle action distance is 11-12 mm.

8. The method of manufacturing a microfiber nonwoven material according to claim 1, wherein The soaking, the fiber after the first water jet reinforcement is completely soaked in a soaking liquid, soaked at room temperature for 30-50 min to obtain a soaked fiber web; The soaking liquid is a cationic polyacrylamide aqueous solution, wherein the molecular weight of the cationic polyacrylamide is 8 million, the ionicity is 30 wt.%, and the mass concentration is 0.01%.

9. The method of manufacturing a microfiber nonwoven material according to claim 1, wherein The second water jet reinforcement, the soaked fiber web is introduced into a water jet machine for second water jet reinforcement to obtain a fiber web after second water jet reinforcement; the second water jet reinforcement is divided into three passes, the water needle pressure of the first pass of water jet reinforcement is 14-15 MPa, the water needle aperture is 0.13 mm, and the water needle action distance is 13-14 mm; the water needle pressure of the second pass of water jet reinforcement is 16-17 MPa, the water needle aperture is 0.16 mm, and the water needle action distance is 13-14 mm; the water needle pressure of the third pass of water jet reinforcement is 19-20 MPa, the water needle aperture is 0.16 mm, and the water needle action distance is 11-12 mm.

10. The method of manufacturing a microfiber nonwoven material according to claim 1, wherein The calendering and drying, the fiber web after the second water jet reinforcement is calendered, the linear pressure during calendering is controlled to be 130-140 N / cm, and then dried, the temperature during drying is controlled to be 140-150 DEG C, to obtain a dried fiber web; The electret, the dried fiber web is subjected to electret treatment and then wound to obtain an ultra-fine fiber non-woven material; the electret voltage in the electret treatment is controlled to be 20-30 kV, the electret distance is controlled to be 5-10 cm, and the electret time is controlled to be 20-30 s.

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