Antibacterial melt-blown non-woven fabric and preparation method thereof

Abstract

The preparation method comprises the following steps: firstly, carrying out plasma treatment on polypropylene, then soaking in a solution containing acrylic acid, fumaric acid and an initiator, and carrying out microwave irradiation, ultraviolet irradiation and post-treatment to obtain modified polypropylene; preparing nano cellulose by taking guanidine carbonate, glutaric acid and bagasse as raw materials; then mixing the modified polypropylene and the nano cellulose, performing melt extrusion, forming fibers, cooling the fibers, and forming a net to obtain gray fabric; and finally, heating the gray fabric to fiberize part of graphite on the surface of the gray fabric, and adding static electricity to obtain the melt-blown non-woven fabric. The obtained melt-blown non-woven fabric has excellent antibacterial performance, can inhibit bacteria for a long time, does not affect air permeability, and can be used for mask manufacturing.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-woven fabric preparation, and particularly relates to an antibacterial melt-blown non-woven fabric and a preparation method thereof. Background Art

[0002] Non-woven fabrics are composed of oriented or random fibers, also known as non-woven cloth, needle-punched cotton, etc. Melt-blown non-woven fabric is a type of non-woven fabric with a fluffy structure, many pores, a unique capillary structure, a large number of fibers per unit area and a large specific surface area, and has good filtration, shielding, oil absorption, and heat insulation properties. Melt-blown non-woven fabrics are widely used in fields such as filter materials, oil absorption materials, thermal insulation materials, and mask materials.

[0003] Melt-blown non-woven fabrics are usually processed according to the following process: polymer feeding, melting extrusion, fiber formation, fiber cooling, web forming, and consolidation into fabric. Currently, the main raw material for processing melt-blown non-woven fabrics is polypropylene with a high melt index. First, the polypropylene is melted by a high-pressure hot air stream, and then the polymer melt stream extruded from the die spinneret holes is drawn by high-speed hot air to form ultrafine fibers, which are condensed on a coagulation net curtain or a drum and become a non-woven fabric by self-bonding. The fiber diameter of the melt-blown non-woven fabric is 0.5 - 10 μm, and the formed unique fiber structure has a good filtering effect. After high-voltage electret electrostatic treatment, the fibers are given electrostatic adsorption ability, and fine dust particles can be collected through the electrostatic effect, and it has a good blocking and filtering effect on aerosols, bacterial smoke, etc. in the atmosphere.

[0004] In recent years, with the increasing attention of people to health, melt-blown non-woven fabrics have developed rapidly in mask manufacturing. A mask is a common health protection product that can filter the air entering the mouth and nose and block harmful gases, odors, droplets, etc. However, the antibacterial ability of traditional melt-blown non-woven fabrics is poor, and antibacterial performance must be considered when manufacturing masks.

[0005] In order to improve the antibacterial performance of melt-blown non-woven fabrics, inorganic antibacterial fibers such as silver, copper, and zinc are introduced into fibers without antibacterial function through different processing methods to make them antibacterial. However, these inorganic antibacterial fibers have problems such as high cost, limited loading capacity, poor bonding fastness, and heavy metal toxicity, which limit their popularization and use.

[0006] Patent application CN116815415A discloses a flame-retardant and antibacterial polypropylene melt-blown non-woven fabric and its preparation method. First, AIF-8 is impregnated in an aqueous silver nitrate solution, stirred, centrifuged, and washed with deionized water to remove surface-adsorbed ions, obtaining a solid product, which is transferred to a muffle furnace for calcination to obtain an Ag-ZnO composite; then the Ag-ZnO composite, IFR, and PP are melt-mixed under the operation of a twin-screw extruder, sent to a spinneret through a metering pump, blown out by a blower and then laid into a web, and the melt-blown non-woven fabric is collected. This melt-blown non-woven fabric mainly relies on the Ag-ZnO composite to achieve antibacterial properties. When the addition amount is 4wt%, the antibacterial rate against Escherichia coli, Staphylococcus aureus, and Candida albicans can reach more than 99%. The silver dosage is relatively large, which will undoubtedly increase the production cost. Moreover, the Ag-ZnO composite has poor compatibility in the system, poor production uniformity, large differences in antibacterial properties between different batches, and is also prone to free out during storage and use, thus losing its antibacterial properties. Summary of the Invention

[0007] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an antibacterial melt-blown non-woven fabric and its preparation method, which has excellent antibacterial properties, can have long-term antibacterial effects, does not affect air permeability, and can be used for mask manufacturing.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A preparation method of an antibacterial melt-blown non-woven fabric, comprising the following steps:

[0010] (1) First, plasma treatment is carried out on polypropylene, and then it is soaked in a solution containing acrylic acid, fumaric acid, and an initiator, irradiated with microwaves, irradiated with ultraviolet light, and post-treated to obtain modified polypropylene;

[0011] (2) Then, guanidine carbonate, glutaric acid, and bagasse are used as raw materials to prepare nanocellulose;

[0012] (3) Then, the modified polypropylene and nanocellulose are mixed, melt-extruded, fiber formation is carried out, the fibers are cooled, and a web is formed to obtain a blank fabric;

[0013] (4) Finally, the blank fabric is heat-treated to make part of the surface of the blank fabric graphitized, and electrostatic addition is carried out to obtain the melt-blown non-woven fabric.

[0014] Preferably, in step (1), the plasma treatment power is 50 - 70kW, the voltage is 380V, and the specific process is as follows: evacuate to 100 - 200Pa, introduce argon at 30 - 40cm 3 / s, carry out plasma treatment for 40 - 50s; then introduce ammonia at 20 - 30cm 3 / s, and carry out plasma treatment for 80 - 90s.

[0015] Preferably, in step (1), by weight, the solution comprises: 35 - 45 parts of acrylic acid, 10 - 20 parts of fumaric acid, 0.1 - 0.2 parts of initiator, and 100 parts of absolute ethanol; the initiator is benzoyl peroxide or azobisisobutyronitrile.

[0016] Preferably, in step (1), the process conditions of microwave irradiation are: microwave irradiation at 400 - 500 W for 3 - 4 minutes, stop for 1 minute, and cycle like this until the cumulative irradiation time reaches 40 - 50 minutes.

[0017] Preferably, in step (1), the process conditions of ultraviolet irradiation are: irradiation wavelength 300 nm, power 800 - 1000 W, and treatment time 10 - 20 minutes.

[0018] Preferably, in step (1), the post - treatment method is: rinsing with deionized water 3 - 5 times, and vacuum drying at 70 - 80 °C for 5 - 7 hours.

[0019] Preferably, the specific method of step (2) is: mixing guanidine carbonate and glutaric acid in a molar ratio of 1:3, stirring and mixing at 90 - 100 °C for 1 hour to obtain a premix, then pre - treating bagasse to obtain pre - treated bagasse, and then mixing the premix and the pre - treated bagasse evenly by mass, irradiating with microwave at 400 - 500 W for 3 - 4 minutes, stopping for 1 minute, and cycling like this until the cumulative irradiation time reaches 60 - 70 minutes, transferring to a ball mill, ball - milling at 400 - 500 rpm for 6 hours, filtering to obtain the solid, washing with water, and drying to obtain nanocellulose.

[0020] Further preferably, the pre - treatment method of bagasse is as follows: adding bagasse to water with a weight 5 - 6 times that of bagasse, heating and extracting at 90 - 95 °C for 3 - 4 hours, filtering to obtain the solid, which is the pre - treated bagasse.

[0021] Preferably, in step (3), the modified polypropylene and nanocellulose are mixed in a mass ratio of 10:0.8 - 1.

[0022] Preferably, in step (3), the melt - extrusion conditions are: screw temperature 180 - 200 °C, melt - pipe temperature 220 - 230 °C, and die - head temperature 240 - 250 °C.

[0023] Preferably, in step (3), the fiber - forming method is: filtering the molten material obtained by melt - extrusion, evenly feeding it into a spinneret, extruding molten filaments through the spinneret holes, thinning and elongating under the impact of high - speed hot - air flows on both sides, and forming fibers through hot - air drawing; wherein, the hot - air volume is 4000 - 4200 m 3 / h, and the hot - air temperature is 250 - 260 °C.

[0024] Preferably, in step (3), the fiber cooling method is as follows: spraying water vapor from one side of the fiber to achieve cooling, with the water vapor pressure ratio on both sides of the fiber being 1:3, and cooling the fiber to 65-70 °C.

[0025] Preferably, in step (3), the web-forming method is as follows: spraying the cooled fiber onto a forming screen, and bonding and aggregating the fiber onto it through air suction at the bottom of the screen to form a web; the air suction volume is 1300-1400 m 3 / h.

[0026] Preferably, in step (4), the heat treatment method is as follows: heating in air to 230-250 °C and holding for 30-40 minutes; heating in high-purity nitrogen to 1400-1500 °C and holding for 5-10 minutes; heating in high-purity argon at 20-30 °C / min to 2800-2900 °C and immediately stopping heating.

[0027] Preferably, in step (4), electrostatic addition is achieved through an electrostatic field formed by an electrostatic generator, with the voltage of the electrostatic generator being 50-60 V and the current being 10-12 mA.

[0028] An antibacterial meltblown non-woven fabric is obtained by the foregoing preparation method.

[0029] The application of the foregoing antibacterial meltblown non-woven fabric in mask manufacturing.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention provides an antibacterial meltblown non-woven fabric and a preparation method thereof. First, polypropylene is subjected to plasma treatment, then immersed in a solution containing acrylic acid, fumaric acid and an initiator, irradiated with microwaves and ultraviolet rays, and post-treated to obtain modified polypropylene; then, guanidine carbonate, glutaric acid and bagasse are used as raw materials to prepare nanocellulose; then, the modified polypropylene and nanocellulose are mixed, melt-extruded, fibers are formed, the fibers are cooled, and a web is formed to obtain a blank fabric; finally, the blank fabric is heat-treated to partially graphitize the surface of the blank fabric and electrostatically added to obtain the meltblown non-woven fabric. The meltblown non-woven fabric obtained by the present invention has excellent antibacterial properties, can inhibit bacteria for a long time, does not affect air permeability, and can be used in mask manufacturing.

[0032] The main raw material of the present invention is polypropylene. Acrylic acid and fumaric acid are used to modify polypropylene, introducing carbon-carbon double bonds and carboxylic acids, which can destroy the cell wall of bacteria or affect the metabolic process of bacteria, endowing the modified polypropylene with antibacterial properties. During preparation, polypropylene is first subjected to plasma treatment to generate active groups and provide reactive sites, and through the synergistic effect of microwave irradiation and ultraviolet irradiation, the modification treatment of polypropylene is promoted.

[0033] The present invention prepares antibacterial nanocellulose using guanidine carbonate, glutaric acid and bagasse as raw materials. The modified polypropylene and nanocellulose act synergistically to further improve antibacterial properties.

[0034] Finally, the present invention conducts heat treatment on the base fabric, causing partial graphitization of the base fabric surface and in-situ generation of graphite fibers on the base fabric surface, which can damage the bacterial cell membrane and further improve the antibacterial performance of the product. Moreover, the generation of graphite fibers does not affect the air permeability of the non-woven fabric. Specific Embodiments

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0036] The polypropylene involved in the present invention is the special raw material PP G1500 for meltblown cloth, purchased from Dongguan Dongshuo Plastic Raw Materials Co., Ltd.

[0037] All other commodities in the present invention are purchased through market channels.

[0038] Example 1

[0039] A preparation method of antibacterial meltblown non-woven fabric includes the following steps:

[0040] (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid and an initiator, followed by microwave irradiation, ultraviolet irradiation and post-treatment to obtain modified polypropylene;

[0041] The plasma treatment power is 50kW and the voltage is 380V. The specific process is as follows: evacuate to 100Pa, introduce argon at 30cm 3 / s for 40s of plasma treatment; then introduce ammonia at 20cm 3 / s for 80s of plasma treatment.

[0042] The solution includes: 3.5kg of acrylic acid, 1kg of fumaric acid, 0.01kg of initiator, and 10kg of anhydrous ethanol; the initiator is benzoyl peroxide.

[0043] The process conditions for microwave irradiation are: irradiate with 400W microwave for 3 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 40 minutes.

[0044] The process conditions for ultraviolet irradiation are: irradiation wavelength 300nm, power 800W, and treatment time 10 minutes.

[0045] The post-treatment method is as follows: rinse with deionized water three times and dry in vacuum at 70 °C for 5 hours.

[0046] (2) Then, using guanidine carbonate, glutaric acid, and bagasse as raw materials, prepare nanocellulose;

[0047] The specific method is as follows: mix guanidine carbonate and glutaric acid according to a molar ratio of 1:3, stir and mix at 90 °C for 1 hour to obtain a premix. Then, pretreat the bagasse to obtain pretreated bagasse. Next, mix the premix and the pretreated bagasse evenly by mass, irradiate with 400 W microwave for 3 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 60 minutes. Transfer the mixture to a ball mill and mill at 400 rpm for 6 hours. Filter to obtain the solid, wash it with water, and dry it to obtain nanocellulose.

[0048] The pretreatment method of bagasse is as follows: add bagasse to water with a weight 5 times that of the bagasse, heat and extract at 90 °C for 3 hours, filter to obtain the solid, which is the pretreated bagasse.

[0049] (3) Then, mix modified polypropylene and nanocellulose according to a mass ratio of 10:0.8, melt and extrude, form fibers, cool the fibers, and form a web to obtain a green fabric;

[0050] Melt extrusion: the screw temperature is 180 °C, the melt pipe temperature is 220 °C, and the die head temperature is 240 °C.

[0051] Fiber formation: filter the molten material obtained by melt extrusion, evenly feed it into a spinneret, extrude molten filaments from the spinneret holes, and make them thinner and longer under the impact of high-speed hot air flows on both sides. After hot air drawing, fibers are formed. Among them, the hot air volume is 4000 m 3 / h, and the hot air temperature is 250 °C.

[0052] Fiber cooling: cool the fibers by spraying water vapor from one side of the fibers. The water vapor pressure ratio on both sides of the fibers is 1:3, and cool the fibers to 65 °C.

[0053] Web formation: spray the cooled fibers onto a forming curtain, and bond the fibers on it by suction through the bottom of the web to form a web; the suction air volume is 1300 m 3 / h.

[0054] (4) Finally, heat-treat the green fabric to make part of the surface of the green fabric graphitized and add static electricity to obtain the meltblown nonwoven fabric described.

[0055] The heat-treatment method is as follows: heat in air to 230 °C and keep warm for 30 minutes; heat in high-purity nitrogen to 1400 °C and keep warm for 5 minutes; heat in high-purity argon at a rate of 20 °C / min to 2800 °C and immediately stop heating.

[0056] Electrostatic addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 50 V, and the current is 10 mA.

[0057] Example 2

[0058] A preparation method of antibacterial meltblown non-woven fabric includes the following steps:

[0059] (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid, and an initiator, followed by microwave irradiation, ultraviolet irradiation, and post-treatment to obtain modified polypropylene.

[0060] The power of the plasma treatment is 70 kW, and the voltage is 380 V. The specific process is as follows: evacuate to 200 Pa, introduce argon at 40 cm 3 / s for 50 s of plasma treatment; then introduce ammonia at 30 cm 3 / s for 90 s of plasma treatment.

[0061] The solution includes: 4.5 kg of acrylic acid, 2 kg of fumaric acid, 0.02 kg of initiator, and 10 kg of absolute ethanol; the initiator is azobisisobutyronitrile.

[0062] The process conditions for microwave irradiation are: irradiate with 500 W of microwave for 4 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 50 minutes.

[0063] The process conditions for ultraviolet irradiation are: irradiation wavelength 300 nm, power 1000 W, and treatment time 20 minutes.

[0064] The post-treatment method is: rinse 5 times with deionized water and dry in vacuum at 80 °C for 7 hours.

[0065] (2) Then, use guanidine carbonate, glutaric acid, and bagasse as raw materials to prepare nanocellulose.

[0066] The specific method is as follows: mix guanidine carbonate and glutaric acid according to a molar ratio of 1:3, stir and mix at 100 °C for 1 hour to obtain a premix. Then, pretreat bagasse to obtain pretreated bagasse. Then, mix the premix and the pretreated bagasse evenly by mass, irradiate with 500 W of microwave for 4 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 70 minutes. Transfer to a ball mill and mill at 500 rpm for 6 hours. Filter by suction to obtain the solid, wash it with water, and dry it to obtain nanocellulose.

[0067] The pretreatment method of bagasse is as follows: add bagasse to water with a weight 6 times that of bagasse, heat and extract at 95 °C for 4 hours, filter by suction to obtain the solid, which is the pretreated bagasse.

[0068] (3) Then, mix the modified polypropylene and nano-cellulose in a mass ratio of 10:1, perform melt extrusion, fiber formation, fiber cooling, and web formation to obtain a base fabric;

[0069] Melt extrusion: The screw temperature is 200°C, the melt pipe temperature is 230°C, and the die head temperature is 250°C.

[0070] Fiber formation: Filter the molten material obtained from melt extrusion, uniformly feed it into a spinneret plate, extrude molten filaments from the spinneret holes, and make them thinner and longer under the impact of high-speed hot air flows on both sides. After hot air drawing, fibers are formed; among them, the hot air volume is 4200 m 3 / h, and the hot air temperature is 260°C.

[0071] Fiber cooling: Achieve cooling by spraying water vapor from one side of the fiber. The water vapor pressure ratio on both sides of the fiber is 1:3, and the fiber is cooled to 70°C.

[0072] Web formation: Spray the cooled fibers onto a forming curtain, and bond the fibers on it through air suction at the bottom of the net to form a web; the air suction volume is 1400 m 3 / h.

[0073] (4) Finally, perform heat treatment on the base fabric to make part of the surface of the base fabric graphitized and add static electricity, thus obtaining the meltblown non-woven fabric described.

[0074] The heat treatment method is: Heat in air to 250°C and keep warm for 40 minutes; heat in high-purity nitrogen to 1500°C and keep warm for 10 minutes; heat in high-purity argon at a rate of 30°C / min to 2900°C and immediately stop heating.

[0075] Realize static electricity addition through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 60V and the current is 12mA.

[0076] Example 3

[0077] A preparation method of an antibacterial meltblown non-woven fabric includes the following steps:

[0078] (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid, and an initiator, perform microwave irradiation, ultraviolet irradiation, and post-treatment to obtain modified polypropylene;

[0079] The plasma treatment power is 50kW and the voltage is 380V. The specific process is: Vacuumize to 200Pa, introduce argon at 30 cm 3 / s, perform plasma treatment for 50s; then introduce ammonia at 20 cm 3 / s, perform plasma treatment for 90s.

[0080] The solution includes: 3.5 kg of acrylic acid, 2 kg of fumaric acid, 0.02 kg of initiator, and 10 kg of absolute ethanol; the initiator is benzoyl peroxide.

[0081] The process conditions for microwave irradiation are: microwave irradiation at 400 W for 4 minutes, stop for 1 minute, and so on in cycles until the cumulative irradiation time reaches 40 minutes.

[0082] The process conditions for ultraviolet irradiation are: irradiation wavelength of 300 nm, power of 1000 W, and treatment time of 10 minutes.

[0083] The post-treatment method is: rinse with deionized water 5 times and vacuum dry at 70 °C for 7 hours.

[0084] (2) Then, using guanidine carbonate, glutaric acid, and bagasse as raw materials, prepare nanocellulose;

[0085] The specific method is as follows: mix guanidine carbonate and glutaric acid according to a molar ratio of 1:3, stir and mix at 90 °C for 1 hour to obtain a premix. Then, pretreat the bagasse to obtain pretreated bagasse. Next, mix the premix and the pretreated bagasse in equal mass and mix evenly. Irradiate with microwave at 500 W for 3 minutes, stop for 1 minute, and so on in cycles until the cumulative irradiation time reaches 70 minutes. Transfer to a ball mill and ball mill at 400 rpm for 6 hours. Filter to obtain the solid, wash with water, and dry to obtain nanocellulose.

[0086] The pretreatment method of bagasse is as follows: add bagasse to water with a weight 6 times that of bagasse, heat and extract at 90 °C for 4 hours, filter to obtain the solid, and thus obtain the pretreated bagasse.

[0087] (3) Then, mix the modified polypropylene and nanocellulose according to a mass ratio of 10:0.8, perform melt extrusion, fiber formation, fiber cooling, and web formation to obtain a green fabric;

[0088] Melt extrusion: the screw temperature is 200 °C, the melt pipe temperature is 220 °C, and the die head temperature is 250 °C.

[0089] Fiber formation: filter the molten material obtained by melt extrusion, evenly feed it into a spinneret, extrude molten filaments from the spinneret holes, and make them thinner and longer under the impact of high-speed hot air flows on both sides. After hot air drawing, fibers are formed; among them, the hot air volume is 4000 m 3 / h, and the hot air temperature is 260 °C.

[0090] Fiber cooling: cool by spraying water vapor from one side of the fiber, and the water vapor pressure ratio on both sides of the fiber is 1:3, and cool the fiber to 65 °C.

[0091] Web formation: spray the cooled fibers onto a forming curtain, and bond the fibers on it by suction through the bottom of the net to form a web; the suction air volume is 1400 m 3 / h.

[0092] (4) Finally, heat-treat the grey cloth to make the surface part of the grey cloth graphitized and fibrillated, and perform electrostatic addition to obtain the melt-blown non-woven fabric described above.

[0093] The heat-treatment method is as follows: heat in air to 230 °C and hold for 40 minutes; heat in high-purity nitrogen to 1400 °C and hold for 10 minutes; heat in high-purity argon at 20 °C / min to 2900 °C and immediately stop heating.

[0094] Electrostatic addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 50 V and the current is 12 mA.

[0095] Example 4

[0096] A preparation method of an antibacterial melt-blown non-woven fabric includes the following steps:

[0097] (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid and an initiator, perform microwave irradiation, ultraviolet irradiation, and post-treatment to obtain modified polypropylene;

[0098] The power of the plasma treatment is 60 kW and the voltage is 380 V. The specific process is as follows: evacuate to 150 Pa, introduce argon at 35 cm 3 / s and perform plasma treatment for 45 s; then introduce ammonia at 25 cm 3 / s and perform plasma treatment for 85 s.

[0099] The solution includes: 4 kg of acrylic acid, 1.5 kg of fumaric acid, 0.01 kg of initiator, and 10 kg of anhydrous ethanol; the initiator is azobisisobutyronitrile.

[0100] The process conditions of the microwave irradiation are: irradiate with 500 W microwave for 3 minutes, stop for 1 minute, and cycle like this until the cumulative irradiation is 45 minutes.

[0101] The process conditions of the ultraviolet irradiation are: irradiation wavelength 300 nm, power 1000 W, and treatment time 15 minutes.

[0102] The post-treatment method is: rinse with deionized water 4 times and vacuum dry at 75 °C for 6 hours.

[0103] (2) Then, use guanidine carbonate, glutaric acid and bagasse as raw materials to prepare nanocellulose;

[0104] The specific method is as follows: Mix guanidine carbonate and glutaric acid in a molar ratio of 1:3, stir and mix at 95 °C for 1 hour to obtain a premix. Then, pretreat bagasse to obtain pretreated bagasse. Next, mix the premix and the pretreated bagasse in equal mass and mix evenly, irradiate with 450 W microwave for 3 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 65 minutes. Then transfer it to a ball mill and mill at 500 rpm for 6 hours. Filter to obtain the solid, wash it with water, and dry it to obtain nanocellulose.

[0105] The pretreatment method of bagasse is as follows: Add bagasse to water with a weight 5 times that of bagasse, heat and extract at 92 °C for 4 hours, filter to obtain the solid, and thus obtain the pretreated bagasse.

[0106] (3) Then mix modified polypropylene and nanocellulose in a mass ratio of 10:0.9, melt and extrude, form fibers, cool the fibers, and form a web to obtain a green fabric.

[0107] Melt extrusion: The screw temperature is 190 °C, the melt pipe temperature is 225 °C, and the die head temperature is 245 °C.

[0108] Fiber formation: Filter the molten material obtained by melt extrusion, evenly feed it into a spinneret, extrude molten filaments from the spinneret holes, and make them thinner and longer under the impact of high-speed hot air flows on both sides. After hot air drawing, fibers are formed. Among them, the hot air volume is 4100 m 3 / h, and the hot air temperature is 255 °C.

[0109] Fiber cooling: Spray water vapor from one side of the fiber to achieve cooling. The water vapor pressure ratio on both sides of the fiber is 1:3, and the fiber is cooled to 68 °C.

[0110] Web formation: Spray the cooled fibers onto a forming curtain, and bond the fibers onto it through air suction at the bottom of the web to form a web; the air suction volume is 1350 m 3 / h.

[0111] (4) Finally, heat-treat the green fabric to make part of the surface of the green fabric graphitized and add static electricity to obtain the meltblown nonwoven fabric described above.

[0112] The heat-treatment method is as follows: Heat in air to 240 °C and keep warm for 35 minutes; heat in high-purity nitrogen to 1450 °C and keep warm for 7 minutes; heat in high-purity argon at 25 °C / min to 2850 °C and immediately stop heating.

[0113] Static electricity addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 55 V and the current is 11 mA.

[0114] Comparative Example 1

[0115] A preparation method of a meltblown nonwoven fabric includes the following steps:

[0116] (1) First, use guanidine carbonate, glutaric acid, and bagasse as raw materials to prepare nanocellulose;

[0117] The specific method is as follows: Mix guanidine carbonate and glutaric acid in a molar ratio of 1:3, stir and mix at 90 °C for 1 hour to obtain a premix. Then, pretreat the bagasse to obtain pretreated bagasse. Next, mix the premix and the pretreated bagasse evenly by mass, irradiate with 400 W microwave for 3 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 60 minutes. Transfer to a ball mill and mill at 400 rpm for 6 hours. Filter to obtain the solid, wash it with water, and dry it to obtain nanocellulose.

[0118] The pretreatment method of bagasse is as follows: Add bagasse to 5 times its weight of water, heat and extract at 90 °C for 3 hours, filter to obtain the solid, which is the pretreated bagasse.

[0119] (2) Then, mix polypropylene and nanocellulose in a mass ratio of 10:0.8, melt and extrude, form fibers, cool the fibers, and form a web to obtain a green fabric;

[0120] Melt extrusion: The screw temperature is 180 °C, the melt pipe temperature is 220 °C, and the die head temperature is 240 °C.

[0121] Fiber formation: Filter the molten material obtained by melt extrusion, uniformly feed it into a spinneret, extrude molten filaments from the spinneret holes, and make them thinner and longer under the impact of high-speed hot air flows on both sides. After hot air drawing, fibers are formed; among them, the hot air volume is 4000 m 3 / h, and the hot air temperature is 250 °C.

[0122] Fiber cooling: Cool by spraying water vapor from one side of the fiber. The water vapor pressure ratio on both sides of the fiber is 1:3, and the fiber is cooled to 65 °C.

[0123] Web formation: Spray the cooled fibers onto a forming curtain, and bond the fibers on it by suction through the bottom of the net to form a web; the suction air volume is 1300 m 3 / h.

[0124] (3) Finally, heat-treat the green fabric to make part of the surface of the green fabric graphitized and add static electricity to obtain the meltblown non-woven fabric described.

[0125] The heat-treatment method is as follows: Heat in air to 230 °C and keep warm for 30 minutes; heat in high-purity nitrogen to 1400 °C and keep warm for 5 minutes; heat in high-purity argon at 20 °C / min to 2800 °C and immediately stop heating.

[0126] Static electricity addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 50 V, and the current is 10 mA.

[0127] Comparative Example 2

[0128] A preparation method of melt-blown non-woven fabric, comprising the following steps:

[0129] (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid and an initiator, irradiate with microwave, irradiate with ultraviolet, and perform post-treatment to obtain modified polypropylene;

[0130] The power of plasma treatment is 50kW and the voltage is 380V. The specific process is as follows: evacuate to 100Pa, introduce argon at 30cm 3 / s for 40s of plasma treatment; then introduce ammonia at 20cm 3 / s for 80s of plasma treatment.

[0131] The solution includes: 3.5kg of acrylic acid, 1kg of fumaric acid, 0.01kg of initiator, and 10kg of absolute ethanol; the initiator is benzoyl peroxide.

[0132] The process conditions of microwave irradiation are: irradiate with 400W microwave for 3 minutes, stop for 1 minute, and cycle like this until the cumulative irradiation is 40 minutes.

[0133] The process conditions of ultraviolet irradiation are: irradiation wavelength 300nm, power 800W, and treatment time 10 minutes.

[0134] The post-treatment method is: rinse 3 times with deionized water and dry in vacuum at 70°C for 5 hours.

[0135] (2) Then melt-extrude the modified polypropylene, form fibers, cool the fibers, and form a web to obtain a base fabric;

[0136] Melt extrusion: the screw temperature is 180°C, the melt pipe temperature is 220°C, and the die head temperature is 240°C.

[0137] Fiber formation: filter the molten material obtained by melt extrusion, uniformly feed it into the spinneret, extrude molten filaments from the spinneret holes, make them thinner and longer under the impact of high-speed hot air flows on both sides, and form fibers through hot air drawing; among them, the hot air volume is 4000m 3 / h and the hot air temperature is 250°C.

[0138] Fiber cooling: cool by spraying water vapor from one side of the fiber, the water vapor pressure ratio on both sides of the fiber is 1:3, and cool the fiber to 65°C.

[0139] Web formation: spray the cooled fibers onto the forming curtain, and bond the fibers on it by suction through the bottom of the net to form a web; the suction air volume is 1300m 3 / h.

[0140] (3) Finally, heat-treat the grey cloth so that partial graphite on the surface of the grey cloth is fibrillated, and perform electrostatic addition to obtain the melt-blown non-woven fabric as described.

[0141] The heat-treating method is as follows: heat in air to 230 °C and hold for 30 minutes; heat in high-purity nitrogen to 1400 °C and hold for 5 minutes; heat in high-purity argon at 20 °C / min to 2800 °C and immediately stop heating.

[0142] Electrostatic addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 50 V and the current is 10 mA.

[0143] Comparative Example 3

[0144] A method for preparing a melt-blown non-woven fabric includes the following steps:

[0145] (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid and an initiator, perform microwave irradiation, ultraviolet irradiation, and post-treatment to obtain modified polypropylene;

[0146] The power of the plasma treatment is 50 kW and the voltage is 380 V. The specific process is as follows: evacuate to 100 Pa, introduce argon at 30 cm 3 / s and perform plasma treatment for 40 s; then introduce ammonia at 20 cm 3 / s and perform plasma treatment for 80 s.

[0147] The solution includes: 3.5 kg of acrylic acid, 1 kg of fumaric acid, 0.01 kg of initiator, and 10 kg of absolute ethanol; the initiator is benzoyl peroxide.

[0148] The process conditions for microwave irradiation are: irradiate with 400 W of microwave for 3 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 40 minutes.

[0149] The process conditions for ultraviolet irradiation are: irradiation wavelength 300 nm, power 800 W, and treatment time 10 minutes.

[0150] The post-treatment method is: rinse with deionized water 3 times and vacuum dry at 70 °C for 5 hours.

[0151] (2) Then, use guanidine carbonate, glutaric acid and bagasse as raw materials to prepare nanocellulose;

[0152] The specific method is as follows: Mix guanidine carbonate and glutaric acid in a molar ratio of 1:3, stir and mix at 90 °C for 1 hour to obtain a premix. Then, pretreat bagasse to obtain pretreated bagasse. Next, mix the premix and the pretreated bagasse evenly by mass, irradiate with 400 W microwave for 3 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 60 minutes. Transfer to a ball mill and mill at 400 rpm for 6 hours. Filter by suction to obtain the solid, wash with water, and dry to obtain nanocellulose.

[0153] The pretreatment method of bagasse is as follows: Add bagasse to water with a weight 5 times that of bagasse, heat and extract at 90 °C for 3 hours, filter by suction to obtain the solid, and thus obtain the pretreated bagasse.

[0154] (3) Then, mix modified polypropylene and nanocellulose in a mass ratio of 10:0.8, melt and extrude, form fibers, cool the fibers, form a web, and add electrostatic charge to obtain the meltblown nonwoven fabric.

[0155] The electrostatic addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 50 V and the current is 10 mA.

[0156] Test Examples

[0157] Test the air permeability resistance of the meltblown nonwoven fabrics obtained in Examples 1 to 4 according to the method of reference standard YY0469-2023 (the test area is 4.9 cm 2 ).

[0158] Investigate the antibacterial property and long-term antibacterial property of the meltblown nonwoven fabrics obtained in Examples 1 to 4 and Comparative Examples 1 to 3. For the test of antibacterial property, refer to GB / T20944.3-2008. Respectively put the nonwoven fabric specimens into the bacterial solutions of Staphylococcus aureus, Escherichia coli or Candida albicans, oscillate at about 25 °C for 1 minute, suck out the bacterial solution and culture at about 37 °C for 48 hours (for Staphylococcus aureus and Escherichia coli) or 72 hours (for Candida albicans), and calculate the antibacterial rate (initial antibacterial rate).

[0159] Respectively wash the 50 mm×50 mm nonwoven fabric specimens with distilled water 30 times, with 50 mL of distilled water used each time. After natural drying, test the antibacterial rate again to investigate the long-term antibacterial property.

[0160] The test results are shown in Table 1 and Table 2.

[0161] Table 1. Test Results of Air Permeability Resistance

[0162] Ventilation resistance (Pa) Example 1 18 Example 2 18 Example 3 17 Example 4 16

[0163] Table 2. Investigation of Antibacterial Property and Long-Term Antibacterial Property

[0164]

[0165] As can be seen from Table 1, the melt-blown nonwoven fabrics obtained in Examples 1 to 4 have low air permeability resistance, indicating good air permeability and being suitable for mask manufacturing.

[0166] As can be seen from Table 2, the melt-blown nonwoven fabrics obtained in Examples 1 to 4 have very good antibacterial properties against Staphylococcus aureus, Escherichia coli, and Candida albicans. Even after being washed 30 times with distilled water, they still have a relatively high antibacterial rate, indicating good long-term antibacterial properties.

[0167] In Comparative Example 1, the modification treatment of polypropylene was omitted. In Comparative Example 2, nanocellulose was omitted. In Comparative Example 3, the heat treatment of the base fabric was omitted. The antibacterial properties of the obtained melt-blown nonwoven fabrics were significantly deteriorated. The long-term antibacterial properties of Comparative Example 3 were significantly deteriorated, indicating that the heat treatment of the base fabric is beneficial to the long-term maintenance of the antibacterial properties of the nonwoven fabric.

[0168] The present invention uses the above examples to illustrate the technical concept of the present invention. However, the present invention is not limited to the above examples, that is, it does not mean that the present invention must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent substitution of individual raw materials of the products of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of antibacterial meltblown non-woven fabric, characterized in that, It includes the following steps: (1) First, perform plasma treatment on polypropylene, then soak it in a solution containing acrylic acid, fumaric acid and an initiator, followed by microwave irradiation, ultraviolet irradiation, and post-treatment to obtain modified polypropylene; (2) Then, use guanidine carbonate, glutaric acid and bagasse as raw materials to prepare nanocellulose; (3) Next, mix the modified polypropylene and nanocellulose, perform melt extrusion, fiber formation, fiber cooling, and web formation to obtain a greige fabric; (4) Finally, perform heat treatment on the greige fabric to cause partial graphitization of the surface of the greige fabric, and electrostatic addition to obtain the meltblown non-woven fabric.

2. The preparation method according to claim 1, characterized in that, In step (1), the plasma treatment power is 50 - 70 kW, and the voltage is 380 V. The specific process is as follows: evacuate to 100 - 200 Pa, introduce argon at 30 - 40 cm 3 / s for 40 - 50 s of plasma treatment; then introduce ammonia at 20 - 30 cm 3 / s for 80 - 90 s of plasma treatment.

3. The preparation method according to claim 1, wherein In step (1), by weight, the solution includes: 35-45 parts of acrylic acid, 10-20 parts of fumaric acid, 0.1-0.2 parts of initiator, and 100 parts of absolute ethanol; the initiator is benzoyl peroxide or azobisisobutyronitrile.

4. The preparation method according to claim 1, wherein In step (1), the process conditions for microwave irradiation are: microwave irradiation at 400-500W for 3-4 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 40-50 minutes; The process conditions for ultraviolet irradiation are: irradiation wavelength of 300nm, power of 800-1000W, and treatment time of 10-20 minutes.

5. The preparation method according to claim 1, characterized in that, The specific method of step (2) is: mix guanidine carbonate and glutaric acid in a molar ratio of 1:3, stir and mix at 90-100°C for 1 hour to obtain a premix, then pretreat bagasse to obtain pretreated bagasse, then mix the premix and pretreated bagasse evenly by mass, perform microwave irradiation at 400-500W for 3-4 minutes, stop for 1 minute, and repeat this cycle until the cumulative irradiation time reaches 60-70 minutes, transfer to a ball mill, ball mill at 400-500rpm for 6 hours, filter to obtain the solid, wash with water, and dry to obtain nanocellulose.

6. The preparation method according to claim 1, wherein In step (3), the modified polypropylene and nanocellulose are mixed in a mass ratio of 10:0.8-1.

7. The preparation method according to claim 1, wherein In step (3), the melt extrusion conditions are: screw temperature of 180-200°C, melt pipe temperature of 220-230°C, and die head temperature of 240-250°C; The fiber forming method is as follows: filtering the molten material obtained by melt extrusion, uniformly feeding it into a spinneret, extruding molten filaments through spinneret holes, making them thinner and longer under the impact of high-speed hot air flows on both sides, and forming fibers through hot air drafting; wherein, the hot air volume is 4000-4200 m 3 / h, and the hot air temperature is 250-260 °C; The fiber cooling method is: spray water vapor from one side of the fiber to achieve cooling, and the water vapor pressure ratio on both sides of the fiber is 1:3, and cool the fiber to 65-70°C; The web-forming method is as follows: the cooled fibers are sprayed onto the forming wire cloth, and the fibers are bonded and agglomerated on it by suction air at the bottom of the net; the suction air volume is 1300 - 1400 m 3 / h.

8. The preparation method according to claim 1, wherein In step (4), the heat treatment method is: heat in air to 230-250°C and hold for 30-40 minutes; heat in high-purity nitrogen to 1400-1500°C and hold for 5-10 minutes; heat in high-purity argon at 20-30°C / min to 2800-2900°C and immediately stop heating; Electrostatic addition is achieved through an electrostatic field formed by an electrostatic generator. The voltage of the electrostatic generator is 50-60V and the current is 10-12mA.

9. An antibacterial meltblown non-woven fabric, characterized in that, It is obtained by the preparation method described in any one of claims 1-8.

10. Use of the antibacterial meltblown non-woven fabric described in claim 9 in mask manufacturing.

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