CN104722216B - A kind of preparation method of composite air filter membrane - Google Patents

Abstract

The invention relates to a preparation method for a composite air filter membrane, and belongs to the technical field of air filter. The method comprises the following steps: loading a layer of a high-molecular polymer nanofibre membrane material on a non-woven cloth material as a filter layer through a processing method of electrostatic spinning, then loading a layer of a breathable support material made from the same material or other materials on the surface of the composite material by virtue of ultrasonic compounding, thus forming the efficient composite air filter membrane, and producing a pleating filter through pleat processing. The efficient composite air filter membrane prepared by the method disclosed by the invention is good in pleating performance, low in air resistance and long in service life, has an excellent PM0.3-PM10 filtrability, and can be used for a respirator material under atrocious weather conditions. According to the method, the low-density nano-membrane provides great particle filterability, and the breathable support material provides rigidity, so that the composite material is easily subjected to the pleat processing.

Description

A kind of preparation method of composite air filter membrane

technical field

The invention relates to a preparation method of a composite air filter membrane, belonging to the technical field of air filter.

Background technique

As people pay more and more attention to the atmospheric environment and indoor air quality, the environmental standards are becoming stricter and stricter. To achieve a high level of air cleanliness, the selected filter materials must have superior filter performance. In recent years, various high-efficiency air filter materials have made great progress. High-efficiency air filter materials have the characteristics of high filtration efficiency, small airflow resistance, high mechanical strength and good uniformity, and can meet the special functional requirements of air filter materials in specific industries.

At present, commercial filter materials mainly include: (1) melt-blown electret non-woven fabric materials, such as patent US4874659, US4178157, and the combination of melt-blown non-woven fabric and glass fiber paper, such as patent CN101352631; (2) nano-membrane materials, such as Patent CN101795747 discloses a nanofiber filter material made of fibers and microbeads, and patent CN03129430 discloses a polytetrafluoroethylene composite membrane filter material.

In order to effectively improve the filtration efficiency of the filter material, the filter material is usually pleated to increase the filtration area to improve its filtration efficiency.

Melt-blown electret nonwoven material is based on electrostatic charge to achieve effective capture of particles. The performance of this filter material is seriously affected by air humidity, resulting in charge loss. When the electrostatic charge is neutralized due to the adsorption of tiny particles, its performance declines. Moreover, the melt-blown nonwoven material itself is thin, relatively soft, and has poor rigidity, so it is not suitable for pleat processing. However, the use of glass fiber composite melt-blown non-woven fabric materials, due to the dense structure of glass fiber paper and small and few voids, will result in high filtration resistance, and the glass fiber is relatively fragile during the pleating process, resulting in loss of productivity.

Nano-membrane materials, especially electrospun fiber membranes, have low strength, and it is not economical to prepare electrospun membranes with high surface density. Therefore, the best filtration effect cannot be achieved when pure nano-membrane materials are used as filter materials. However, other membrane material processing methods, such as the patent CN03129430, use the phase transition method to form pores and form membranes, and the pore size of the membrane cannot be controlled, resulting in uncontrollable filtration accuracy.

Electrospinning is a new development of traditional solution dry spinning and melt spinning of chemical fibers, and is currently the most important method for manufacturing ultrafine fibers such as nanofibers. It is obviously different from the traditional method, which brings thousands to tens of thousands of volts of high-voltage static electricity to the polymer solution or melt. The core of this technology is to make the charged polymer solution or melt flow and deform in the electrostatic field. When the electric field force is strong enough, the polymer droplets can overcome the surface tension to form a jet stream. Then the fibrous material is solidified by solvent evaporation or melt cooling, so this process is called electrospinning. At present, electrospun nanofibers are difficult to collect separately, and generally end up on the receiving device, forming a fiber mat similar to non-woven fabric.

Due to the fine diameter and large specific surface area of electrospun nanofibers, the nonwoven fabrics formed by such fibers exhibit excellent adsorption properties, and can be used as adsorption media, coated with activated carbon, biocides, etc., and biocides made of these fibers Chemical protective clothing that efficiently absorbs and degrades hazardous liquids and gases. At the same time, this electrospun nanofiber nonwoven fabric is also an excellent filter material with high efficiency and low resistance, and fine particles with a size of 0.3 μm can be easily captured by this type of filter material; in addition to meeting conventional filtration, this polymer nanofiber is compatible with other options After the composite coating of sexual organisms, it can also be applied such as molecular filtration, isolation of chemical and biochemical drugs, etc. Due to the high specific surface area of nanofibers, its application field has been greatly expanded, and it can also be used as a basic material for biomedical materials, cell culture substrates, implanted organs, and tissue carriers.

Invention content:

The purpose of the present invention is to propose a preparation method of a composite air filter membrane, through the processing method of electrospinning, a layer of high molecular polymer nanofiber membrane material is loaded on the non-woven fabric material as a filter layer, and then composited by ultrasonic waves Methods A layer of the same or other breathable support material is loaded on the surface of the composite material to form a high-efficiency composite air filter membrane, which is made into a pleated filter through pleat processing.

The preparation method of the composite air filter membrane that the present invention proposes comprises the following steps:

(1) Lay the non-woven fabric base material on the internally grounded metal plate, the non-woven fabric base material is spunlace polyester/polypropylene (PET/PP) or polylactic acid (PLA), and the non-woven fabric base material The surface density of the woven fabric is 40-85g/m ² ;

(2) dissolving the nanofiber membrane polymer in a solvent to obtain a polymer solution, the mass percent concentration of the polymer solution is 10 to 20 wt%, and the nanofiber membrane polymer is nylon (PA), polyacrylonitrile ( Any one of PAN), polysulfone (PSU), polyvinylidene fluoride (PVDF) or polyethersulfone (PES), polyurethane (PU), polycarbonate (PC), polystyrene (PS), the solvent is Formic acid, acetic acid, chloroform, N,N-dimethylformamide (DMF), dimethylacetamide (DMAC), acetone (AC), tetrahydrofuran (THF), cetyltrimethylammonium bromide (CTAB ) in one or two are mixed in a certain ratio, and the mixing ratio of the solvent is 1:1～1:199;

(3) Add the above-mentioned polymer solution into a micro-syringe, control the ambient humidity to 30-60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle on the above-mentioned metal plate covered with non-woven fabric Above the spinning needle and the metal plate, the distance between the spinning needle and the metal plate is 10-40 cm, and a 12-33 kV high voltage is applied between the spinning needle and the metal plate. solution, spray ultrafine polymer fibers at a flow rate of 0.1-4mL/h, the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate , to obtain the nanofiber membrane filter layer material;

(4) The nonwoven fabric substrate loaded with nanofiber membrane filter layer material is removed from the metal plate, and the upper nonwoven fabric is covered on the above-mentioned nonwoven fabric substrate loaded with nanofiber membrane filter layer material, using Ultrasonic composite method, three layers of composite materials are welded into a composite air filter membrane, the ultrasonic frequency during ultrasonic composite is 20KHz, the welding pressure is 50-200 Newton, and the base material of the upper non-woven fabric is needle-punched polyester (PET), Spunlace polyester/polypropylene (PET/PP) or spun-bonded polypropylene (PP), the surface density of the upper non-woven fabric is 50-85g/m ² .

The preparation method of composite air filter membrane that the present invention proposes, its advantage is:

1. The high-efficiency composite air filter membrane prepared by the method of the present invention has good pleating performance, low wind resistance, long service life, excellent filterability of PM0.3～PM10, and can be used as a mask material under harsh weather conditions.

2. The nanofiber membrane made by electrospinning in the method of the present invention has controllable fiber diameter, so that good pore size and porosity can be guaranteed, and good particle barrier properties are provided for composite materials. The matrix material provides good bursting and breaking strength, which enables the low-density nano-membrane to provide good particle filtration, and the air-permeable support material provides rigidity to make the composite easy to be pleated.

Description of drawings

Figure 1 is a schematic structural view of an electrospinning device involved in the preparation method of the present invention.

Fig. 2 is the electron micrograph of the composite air filter membrane prepared by the method of the present invention.

In Fig. 1, 1 is a syringe, 2 is a spinning needle, 3 is a high-voltage DC power supply, 4 is a nonwoven fabric, and 5 is a metal plate.

detailed description

The preparation method of the composite air filter membrane that the present invention proposes comprises the following steps:

(1) Lay the non-woven fabric base material on the internally grounded metal plate, the non-woven fabric base material is spunlace polyester/polypropylene (PET/PP) or polylactic acid (PLA), and the non-woven fabric base material The surface density of the woven fabric is 40-85g/m ² ;

(2) dissolving the nanofiber membrane polymer in a solvent to obtain a polymer solution, the mass percent concentration of the polymer solution is 10 to 20 wt%, and the nanofiber membrane polymer is nylon (PA), polyacrylonitrile ( Any one of PAN), polysulfone (PSU), polyvinylidene fluoride (PVDF) or polyethersulfone (PES), polyurethane (PU), polycarbonate (PC), polystyrene (PS), the solvent is Formic acid, acetic acid, chloroform, N,N-dimethylformamide (DMF), dimethylacetamide (DMAC), acetone (AC), tetrahydrofuran (THF), cetyltrimethylammonium bromide (CTAB ) in one or two are mixed in a certain ratio, and the mixing ratio of the solvent is 1:1～1:199;

(3) Add the above-mentioned polymer solution into a micro-syringe, control the ambient humidity to 30-60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle on the above-mentioned metal plate covered with non-woven fabric Above the spinning needle and the metal plate, the distance between the spinning needle and the metal plate is 10-40 cm, and a 12-33 kV high voltage is applied between the spinning needle and the metal plate. solution, spray ultrafine polymer fibers at a flow rate of 0.1-4mL/h, the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate , to obtain the nanofiber membrane filter layer material, the schematic diagram of electrospinning in this step is as shown in Figure 1, in Figure 1, 1 is a syringe, 2 is a spinning needle, 3 is a high-voltage direct current power supply, 4 is a nonwoven fabric, 5 is metal plate;

(4) The nonwoven fabric substrate loaded with nanofiber membrane filter layer material is removed from the metal plate, and the upper nonwoven fabric is covered on the above-mentioned nonwoven fabric substrate loaded with nanofiber membrane filter layer material, using Ultrasonic composite method, three layers of composite materials are welded into a composite air filter membrane, the ultrasonic frequency during ultrasonic composite is 20KHz, the welding pressure is 50-200 Newton, and the base material of the upper non-woven fabric is needle-punched polyester (PET), Spunlace polyester/polypropylene (PET/PP) or spun-bonded polypropylene (PP), the surface density of the upper non-woven fabric is 50-85g/m ² .

In the method of the present invention, the nonwoven fabric substrate can be selected according to the difficulty of air permeability of the nonwoven fabric, the surface morphology, dust holding capacity and mechanical strength of the nonwoven fabric substrate. The nonwoven fabric substrate can be needle punched polyester (PET) nonwoven fabric, spunlace polyester/polypropylene (PET/PP) nonwoven fabric, polylactic acid (PLA) nonwoven fabric, spunbonded polypropylene (PP) nonwoven fabric For the cloth, in consideration of economy and processability, spunlace polyester/polypropylene (PET/PP) nonwoven fabric is preferred, and the surface density is controlled at 40-85g/m ² .

In the method of the present invention, the polymer material of the nanofibrous membrane can be nylon (PA), polyacrylonitrile (PAN), polysulfone (PSU), polyvinylidene fluoride (PVDF) or polyethersulfone (PES), polyurethane (PU ), polycarbonate (PC), polystyrene (PS), the solvent is formic acid, acetic acid, chloroform, N, N-dimethylformamide (DMF), dimethylacetamide (DMAC) , acetone (AC), tetrahydrofuran (THF), cetyltrimethylammonium bromide (CTAB), or two are mixed in a certain proportion. In view of economy and environmental friendliness, the polymer material is preferably nylon (PA), and the solvent is formic acid and acetic acid.

When the concentration of the polymer solution is less than 5wt%, it cannot be fibrillated, and if it exceeds 20wt%, it cannot be ejected from the spinning channel. Therefore, the concentration of the polymer solution is preferably 10 to 20%.

Excessive extrusion flow rate of polymer solution during electrospinning process will easily lead to uneven fiber film, resulting in poor filterability, and excessive extrusion flow rate will easily cause dripping and damage to fiber film. Therefore, the extrusion flow rate of polymer solution during electrospinning is 0.1 ~4mL/h.

During electrospinning, the voltage is 10-40 kV; the ambient humidity is 30-60%. The distance between the spinning needle and the receiving material is 10-40cm.

Through the above process control, the nanofiber membrane filter material with a fiber diameter of 0.01-0.3 μm and a thickness of 0.5-5 μm can be produced. The pore diameter of the nano-membrane material is 0.1-2.5 μm. The porosity of the membrane material is 70-98%.

Composite Machining of Composite Materials

Through post-processing technologies such as hot pressing and ultrasonic compounding, the non-woven fabric substrate, nanofiber layer and skeleton reinforcement material are combined to form a composite filter material with a sandwich sandwich structure, so that it can further meet the use requirements of filter materials.

In order to increase the pleating performance of the composite material and further protect the nanofiber layer, it is necessary to add a layer of skeleton nonwoven fabric material on the basis of the composite material manufactured by the above process to improve the rigidity of the composite material and facilitate pleat processing. The skeleton material can be It is a glass fiber reinforced nonwoven fabric, a wet-laid nonwoven fabric, and a thermally bonded nonwoven fabric. From the viewpoint of processability, a wet-laid nonwoven fabric is preferred.

The composite process can be rolling hot pressing and ultrasonic composite. In order to ensure the integrity of the nanofiber membrane material, the ultrasonic composite process is preferred.

The composite air filter membrane material processed by the above processes has good pleating performance, low wind resistance, long service life, and excellent filterability of PM0.3-PM10. Under the test condition of an air volume of 150m ³ /h, the wind resistance is lower than 100Pa, and the PM0.3 filtration rate is greater than 99.6%.

Introduce the embodiment of the inventive method below:

Example 1

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) dissolving the nanofiber membrane polymer nylon (PA) in a solvent having a mixing ratio of formic acid and acetic acid of 4:1 to obtain a polymer solution, and the mass percent concentration of the polymer solution is 12wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 15cm, and a 33 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 0.1mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) The nonwoven fabric substrate loaded with the nanofiber membrane filter layer material is removed from the metal plate, and the upper layer density is 85g/m ² Spunlaced polyester/polypropylene (PET/PP) nonwoven fabric covering On the above-mentioned non-woven fabric substrate loaded with nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by ultrasonic composite method. In the embodiment of the present invention, the ultrasonic composite operation adopts Changzhou Jinpu The Jp-60s ultrasonic compound machine produced by Automation Equipment Co., Ltd. has an ultrasonic working frequency of 20KHz and a welding pressure of 50 Newton.

The electron micrograph of the composite air filter membrane prepared in this embodiment is shown in Fig. 2 .

Example 2

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) dissolving the nanofiber membrane polymer nylon (PA) in a solvent whose mixing ratio of formic acid and acetic acid is 4:1 to obtain a polymer solution, the mass percentage concentration of the polymer solution is 12wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 15cm, and a 33 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 0.1mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 50 Newton.

Example 3

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) dissolving the nanofiber membrane polymer nylon (PA) in a solvent whose mixing ratio of formic acid and acetic acid is 4:1 to obtain a polymer solution, the mass percentage concentration of the polymer solution is 12wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 15cm, and a 33 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 0.1mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) The non-woven fabric substrate loaded with the nanofiber membrane filter layer material is removed from the metal plate, and another needle ^- punched polyester (PET) non-woven fabric with a layer density of 60g/m2 is covered on the above-mentioned load. On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is the Jp-60s type of Changzhou Jinpu Automation Equipment Co., Ltd. Ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 50 Newton.

Example 4

(1) Lay a polylactic acid (PLA) nonwoven substrate with an area density of 40g/m2 ^on an internally grounded metal plate;

(2) dissolving the nanofiber membrane polymer nylon (PA) in a solvent whose mixing ratio of formic acid and acetic acid is 4:1 to obtain a polymer solution, the mass percentage concentration of the polymer solution is 12wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 15cm, and a 33 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 0.1mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) The nonwoven fabric base material loaded with the nanofiber membrane filter layer material is removed from the metal plate, and another layer of spunlace polyester/polypropylene (PET/PP) nonwoven fabric with a density of 85g/ ^m2 Cover the above-mentioned non-woven fabric substrate loaded with nanofiber membrane filter layer material, and use an ultrasonic composite machine to weld the three-layer composite material to obtain a composite air filter membrane. The ultrasonic composite machine is Changzhou Jinpu Automation Equipment Co., Ltd. The company's Jp-60s ultrasonic compound machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 50 Newton.

Example 5

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) Dissolve the nanofiber membrane polymer polyacrylonitrile (PAN) in any of N, N-dimethylformamide (DMF) or dimethylacetamide (DMAC) to obtain a polymer solution, and polymerize The mass percent concentration of the substance solution is 10wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to be 35%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 25cm, and a 22.5 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injection through the pipeline is 1mL/ The flow rate of h sprays ultrafine polymer fibers, and the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate to obtain the nanofiber membrane filter layer material ;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 150 Newton.

Example 6

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) Dissolving the nanofibrous membrane polymer polysulfone (PSU) in N, N-dimethylformamide (DMF) or dimethylacetamide (DMAC) in any one and acetone (AC) mixing ratio is In the solvent of 9:1, obtain polymer solution, the mass percent concentration of polymer solution is 12wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 30%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 20cm, and a 12 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 4mL/ The flow rate of h sprays ultrafine polymer fibers, and the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate to obtain the nanofiber membrane filter layer material ;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 50 Newton.

Example 7

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) dissolving the nanofiber membrane polymer polyvinylidene fluoride (PVDF) in any one of N, N-dimethylformamide (DMF) or dimethylacetamide (DMAC) to obtain a polymer solution, The mass percentage concentration of polymer solution is 10wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 40%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 40cm, and a 22.5 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injection through the pipeline is 3mL/ The flow rate of h sprays ultrafine polymer fibers, and the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate to obtain the nanofiber membrane filter layer material ;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 200 Newton.

Example 8

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) Dissolving the nanofibrous membrane polymer polyethersulfone (PES) in any one of N, N-dimethylformamide (DMF) or dimethylacetamide (DMAC) and the mixing ratio of acetone (AC) In the solvent of 8.5:1.5, obtain polymer solution, the mass percent concentration of polymer solution is 18wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 30%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 10cm, and a 15 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 0.5mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 100 Newton.

Example 9

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) Dissolving the nanofiber membrane polymer polyurethane (PU) in a solvent with a mixing ratio of 1:1 of N, N-dimethylformamide (DMF) and tetrahydrofuran (THF) to obtain a polymer solution, a polymer solution The mass percentage concentration is 10wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 30%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 20cm, and a 20 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 0.9mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 100 Newton.

Example 10

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) nanofiber membrane polymer polycarbonate (PC) is dissolved in the chloroform that cetyltrimethylammonium bromide massfraction is 0.5wt%, obtains polymer solution, the mass percent concentration of polymer solution is 14wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 30%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 10cm, and a 20 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 1.5mL The ultrafine polymer fibers are ejected at a flow rate of /h, and the ultrafine polymer fibers land on the nonwoven fabric substrate on the surface of the metal plate, and the ultrafine polymer fibers on the nonwoven fabric substrate are collected to obtain a nanofiber membrane filter layer Material;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 100 Newton.

Example 11

(1) Lay a spunlace polyester/polypropylene (PET/PP) nonwoven fabric substrate with an area density of 85g/m2 ^on an internally grounded metal plate;

(2) dissolving the nanofiber membrane polymer polystyrene (PS) in N,N-dimethylformamide to obtain a polymer solution, the mass percent concentration of the polymer solution being 20wt%;

(3) Add the above-mentioned polymer solution into the micro-syringe, control the ambient humidity to 30%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle above the above-mentioned metal plate covered with non-woven fabric , the distance between the spinning needle and the metal plate is 15cm, and a 15 kV high voltage is applied between the spinning needle and the metal plate, so that the polymer solution in the spinning needle from the micro-injector through the pipeline is 2mL/ The flow rate of h sprays ultrafine polymer fibers, and the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate to obtain the nanofiber membrane filter layer material ;

(4) Remove the non-woven fabric base material loaded with nanofiber membrane filter layer material from the metal plate, and cover the above-mentioned load with a spun ^- bonded polypropylene (PP) non-woven fabric with a layer density of 50g/m2 On the non-woven fabric substrate of the nanofiber membrane filter layer material, the three-layer composite material is welded to obtain a composite air filter membrane by using an ultrasonic compound machine. The ultrasonic compound machine is Jp-60s of Changzhou Jinpu Automation Equipment Co., Ltd. type ultrasonic composite machine, the ultrasonic working frequency is 20KHz, and the welding pressure is 100 Newton.

Claims (1)

1. A preparation method of composite air filter membrane, characterized in that the preparation method may further comprise the steps: (1) Lay the non-woven fabric base material on the internally grounded metal plate, the described non-woven fabric base material is spunlace polyester/polypropylene, or the described non-woven fabric base material is polylactic acid, the described The surface density of the nonwoven fabric is 40-85g/㎡; (2) dissolving the nanofiber membrane polymer in a solvent to obtain a polymer solution, the mass percent concentration of the polymer solution is 10 to 20 wt%, and the nanofiber membrane polymer is nylon, polyacrylonitrile, polysulfone, Any one of polyvinylidene fluoride or polyethersulfone, polyurethane, polycarbonate, polystyrene, the solvent is formic acid, acetic acid, chloroform, N,N-dimethylformamide, dimethylacetamide, acetone, One or two of tetrahydrofuran and hexadecyltrimethylammonium bromide are mixed in a certain ratio, and the mixing ratio of the solvent is 1:1 to 1:199; (3) Add the above-mentioned polymer solution into a micro-syringe, control the ambient humidity to 30-60%, connect the micro-syringe to the spinning needle through a pipeline, and place the spinning needle on the above-mentioned metal plate covered with non-woven fabric Above the spinning needle and the metal plate, the distance between the spinning needle and the metal plate is 10-40 cm, and a 12-33 kV high voltage is applied between the spinning needle and the metal plate. solution, spray ultrafine polymer fibers at a flow rate of 0.1-4mL/h, the ultrafine polymer fibers land on the non-woven fabric substrate on the surface of the metal plate, and collect the ultrafine polymer fibers on the non-woven fabric substrate , to obtain the nanofiber membrane filter layer material; (4) The nonwoven fabric substrate loaded with nanofiber membrane filter layer material is removed from the metal plate, and the upper nonwoven fabric is covered on the above-mentioned nonwoven fabric substrate loaded with nanofiber membrane filter layer material, using Ultrasonic composite method, three-layer composite material is welded into a composite air filter membrane, the ultrasonic frequency of ultrasonic composite is 20KHz, the welding pressure is 50-200 Newton, the upper non-woven fabric base material is needle-punched polyester, or the upper non-woven fabric base The material is spunlace polyester/polypropylene, or the base material of the upper non-woven fabric is spun-bonded polypropylene, and the surface density of the upper non-woven fabric is 50-85g/㎡.