Electrostatic spinning device for nanofiber industrial preparation

Abstract

The invention relates to the technical field of electrostatic spinning, and discloses an electrostatic spinning device for nanofiber industrial preparation, the device comprises a liquid supply unit, the liquid supply unit comprises a liquid supply device, a liquid supply pipe with one end connected to the output end of the liquid supply device, and a metering pump connected in the liquid supply pipe; the spray pipe unit comprises a spinning spray pipe and a metal needle arranged on the spinning spray pipe; the collecting unit is arranged on the circumferential outer side of the spray pipe unit and comprises a lifting part, a rotating part mounted on the lifting part and a collecting part; the electric field unit comprises a high-voltage power supply, and a positive wire and a negative wire correspondingly connected to the positive electrode and the negative electrode of the high-voltage power supply; according to the multi-needle spinning pipeline arranged based on the three-dimensional curved surface space, the yield of nanofibers in unit space can be increased, the problem that the yield of devices arranged in other modes is too low is solved, electric field distribution in the spinning process is optimized through the multi-needle spinning pipeline arranged based on the three-dimensional curved surface space, electric field interference among different needles is reduced, and the spinning efficiency is improved. And the spinning jet flow is stabilized.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic spinning, and in particular to an electrostatic spinning device for industrial preparation of nanofibers. Background Art

[0002] At present, according to the type and number of spinning needles, solution electrospinning equipment can be divided into two categories: needleless electrospinning equipment and multi-needle electrospinning equipment. Needleless electrospinning is a method of continuous spinning without the need for a needle to form a Taylor cone. Due to the volatilization of the solvent, a layer of polymer film will accumulate over a long spinning time, affecting the spinning effect. In addition, the electrode is prone to splashing the spinning solution when rotating, resulting in a waste of solution, and splashing onto the nanofibers to reduce the quality of the fiber membrane. Multi-needle electrospinning technology is to increase the number of needles on the basis of a single-needle electrospinning device to produce a corresponding number of Taylor cones, thereby effectively improving the spinning efficiency and realizing the mass production of nanofibers. The distribution of multi-needles mainly includes three types: linear, matrix and circular. When increasing the number of needles on a single-needle electrospinning device, the voltage must be increased, resulting in enhanced mutual interference of the electric field. If the electric field strength of the needle is uneven, the external needle jet will be offset, and the produced nanofibers will be uneven, thus affecting the quality of the fiber membrane. During the multi-needle electrospinning process, problems such as needle blockage, electric field interference, and difficulty in cleaning often occur, which seriously affect the fiber yield. The geometric shape and arrangement of the needles will affect the electric field distribution, resulting in uneven electric field strength, which affects the production quality of nanofibers.

[0003] In the invention patent application number: 202011163131.3, Yang Yongsheng et al. provided a matrix multi-needle electrospinning device for improving the production efficiency of nanofibers. The needles are arranged in a 4×6 two-dimensional matrix. There is electric field interference between the needles, the spinning jet is difficult to stabilize, the quality of the spinning product is unstable, and the needle replacement is difficult. Using multiple sets of liquid supply systems, the spinning solution channel is difficult to clean, and the solution supply speed is difficult to unify.

[0004] Invention patent application number: 201811114850.9, Chen Rouxi et al. provided a multi-needle electrospinning device with uniform electric field distribution, which is used to improve the uniformity of fiber membrane and nanofiber production. The needles are distributed in a circular array, and the thickness of the fiber membrane edge is inconsistent with the center. The electric field interference is reduced by increasing the needle spacing. The number of needles is a limiting factor affecting the mass production of electrospun nanofibers, which reduces the production efficiency of nanofibers, and the spinning device is too large.

[0005] In the invention patent application number: 202011346997.8, Wang Han and others provided an industrialized electrospinning collection device, which uses a machine cloth to collect nanofibers. The machine cloth can only move in parallel. Due to the changes in the arrangement density of the spinning needles at different receiving positions, the nanofiber membrane at the edge of the machine cloth is thinner and the nanofiber distribution is uneven, which limits the application range of the nanofiber membrane.

[0006] In general, the key to developing large-scale electrospinning production equipment is to increase the number of spinning needles to produce a corresponding number of Taylor cones, thereby improving the spinning efficiency of nanofibers and realizing their mass production. The needles are distributed in a one-dimensional linear arrangement and a two-dimensional array arrangement. When the number of needles is increased on the basis of a single-needle electrospinning device, the electric field will interfere with each other and the electric field strength will be unevenly distributed, resulting in unstable spinning jets, making the produced nanofiber membranes inconsistent in morphology and uneven in fiber fineness, thereby affecting the quality of the fibers. In addition, multi-needle electrospinning devices also have problems such as difficulty in replacing needles, difficult cleaning of liquid supply pipes, and difficulty in maintenance. In the electrospinning process, the receiving device is a key part for collecting nanofibers. The receiving device is in the form of a flat collecting device, which will lead to uneven fiber distribution, affect the orientation and structure of the fibers, and make it difficult to achieve directional arrangement or multi-layer structure of the fibers. It is urgent to develop an electrospinning device for large-scale production of nanofibers with stable multi-needle spinning jets, high nanofiber yield per unit space, and different fiber arrangements and orientations. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the problems existing in the above-mentioned existing electrospinning devices for industrial preparation of nanofibers, the present invention is proposed.

[0009] Therefore, the purpose of the present invention is to provide an electrospinning device for the industrial preparation of nanofibers, which aims to solve the problems of unreasonable needle distribution and arrangement, easy needle clogging and difficulty in replacement, difficult cleaning of solution pipelines, and low continuous production efficiency in existing electrospinning equipment.

[0010] To solve the above technical problems, the present invention provides the following technical solutions: an electrospinning device for industrial preparation of nanofibers, the electrospinning device comprising a liquid supply unit, a nozzle unit, a collecting unit and an electric field unit, wherein the liquid supply unit comprises a liquid supply device, a liquid supply pipe having one end connected to the output end of the liquid supply device, and a metering pump connected to the liquid supply pipe; the nozzle unit comprises a spinning nozzle and a metal needle arranged on the spinning nozzle, and the end of the liquid supply pipe away from the liquid supply device is connected to the input nozzle of the spinning nozzle; the collecting unit is arranged on the circumferential outer side of the nozzle unit, and comprises a lifting member, a rotating member installed on the lifting member, and a collecting member connected to the output end of the rotating member and suspended between the supporting frames; and the electric field unit comprises a high-voltage power supply and a positive wire and a negative wire correspondingly connected to the positive and negative electrodes of the high-voltage power supply, the end of the positive wire away from the high-voltage power supply is connected to the input nozzle of the spinning nozzle, and the end of the negative wire away from the high-voltage power supply is connected to the collecting member.

[0011] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the spinning nozzle has a cavity inside the tube body, and a needle interface is opened in the side wall of the tube body, and the cavity needle interface is connected to the cavity; the axial ends of the tube body of the spinning nozzle are smoothly transitioned; the metal needle is installed in the needle interface.

[0012] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the needle interfaces are arranged in a plurality of groups in an array with equal spacing along the axis direction of the spinning nozzle, and each group includes , which are evenly distributed with equal arcs.

[0013] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the installation spacing between adjacent metal needles is ~.

[0014] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the lifting component includes a support seat, a threaded rod arranged on the top of the support seat, a threaded drive assembly arranged on the two threaded rods, and a supporting plate installed on the two threaded drive assemblies.

[0015] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the rotating member includes a rotating motor installed in the middle of the supporting plate and a connecting rod arranged on the output shaft of the rotating motor.

[0016] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the collecting member includes a support ring, drive rollers arranged in the inner and outer walls of the support ring, a conveyor belt in rolling contact with the drive rollers, and a metal collecting net arranged on the surface of the conveyor belt.

[0017] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the axial ring body of the support ring has a notch, and the inner and outer walls of the support ring are both provided with mounting grooves; the transmission rollers are arranged at the axial ends of the mounting grooves, and are arranged in pairs, with several groups evenly distributed.

[0018] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, the edge of the conveyor belt is rollingly clamped between the pairs of driving rollers, and the conveyor belt passes through the gap of the support ring and is connected to the inside and outside of the support ring.

[0019] As a preferred solution of the electrospinning device for industrial preparation of nanofibers described in the present invention, a slot is provided on the side wall of the conveyor belt, and the metal collecting net is detachably connected to the surface of the conveyor belt through the slot.

[0020] Beneficial effects of the present invention:

[0021] 1. The multi-needle spinning tube based on the three-dimensional curved surface space arrangement can increase the output of nanofibers per unit space and solve the problem of low output of other arranged devices.

[0022] 2. The multi-needle spinning tube with three-dimensional curved surface space layout optimizes the electric field distribution during the spinning process, reduces the electric field interference between different needles, and stabilizes the spinning jet.

[0023] 3. The lifting and rotating collection method improves the uniformity of the nanofiber membrane through the lifting movement, ensures the consistency of the nanofiber diameter, and reduces the influence of the receiving distance on the nanofiber diameter.

[0024] 4. Changing the rotation speed of the lifting and rotating collection method can prepare oriented nanofibers, which can form fibers with specific arrangements and shapes, and expand the application range of nanofiber membranes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0026] Figure 1 This is a schematic diagram of the overall structure of the electrospinning device for industrial preparation of nanofibers of the present invention.

[0027] Figure 2 This is a schematic structural diagram of the working states of the nozzle unit and the collecting unit of the electrospinning device prepared for industrialization of nanofibers of the present invention.

[0028] Figure 3 This is a schematic diagram of the internal structure of the nozzle unit of the electrospinning device for industrial preparation of nanofibers of the present invention.

[0029] Figure 4 This is a schematic diagram of the collecting unit structure of the electrospinning device for industrial preparation of nanofibers of the present invention.

[0030] Figure 5 This is a schematic diagram of the specific structure of the collecting component of the electrospinning device prepared for industrialization of nanofibers of the present invention.

[0031] Figure 6 This is a schematic diagram of the radial cross-sectional plan structure of the collecting component of the electrospinning device prepared for industrialization of nanofibers of the present invention. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0036] Example 1

[0037] Reference Figure 1 and2 , which is the first embodiment of the present invention, provides an electrospinning device for industrial preparation of nanofibers, the electrospinning device includes a liquid supply unit 100, a nozzle unit 200, a collecting unit 300 and an electric field unit 400, wherein the liquid supply unit 100 is used to accommodate the prepared spinning solution and press the spinning solution into the nozzle unit 200; the nozzle unit 200 uses a specific needle to make the spinning solution form Taylor cone droplets under the action of the electric field force and spray out to solidify into fibers; the collecting unit 300 is used to collect the solidified fibers; the electric field unit 400 is used to form a working voltage between the nozzle unit 200 and the collecting unit 300 to stretch the spinning solution.

[0038] Specifically, the liquid supply unit 100 includes a liquid supply device 101, a liquid supply tube 102 having one end connected to the output end of the liquid supply device 101, and a metering pump 103 connected to the liquid supply tube 102; wherein the liquid supply device 101 is used to contain the spinning solution and can be used to pressurize the spinning solution; the liquid supply tube 102 is used to output the spinning solution in the liquid supply device 101, specifically to the spinning nozzle 201; the metering pump 103 is used for pumping the spinning solution and also for adjusting the flow rate of the spinning solution pumping, thereby realizing the adjustment of the thickness of the nanofibers.

[0039] The nozzle unit 200 includes a spinning nozzle 201 and a metal needle 202 arranged on the spinning nozzle 201. The end of the liquid supply pipe 102 away from the liquid supply device 101 is connected to the input nozzle 201a of the spinning nozzle 201; wherein the spinning nozzle 201 is used for the installation of multiple needles and solution supply, and the metal needle 202 is a key component of electrospinning and is used for the injection of spinning solution.

[0040] The collecting unit 300 is arranged on the circumferential outer side of the nozzle unit 200, and includes a lifting member 301, a rotating member 302 installed on the lifting member 301, and a collecting member 303 connected to the output end of the rotating member 302 and suspended between the support frames 301; wherein the lifting member 301 is used for supporting and height adjusting the rotating member 302 and the collecting member 303, and the rotating member 302 is used for rotation adjustment of the collecting member 303; the collecting member 303 is used for collecting the formed fibers.

[0041] The electric field unit 400 includes a high-voltage power supply 401 and a positive wire 402 and a negative wire 403 connected to the positive and negative electrodes of the high-voltage power supply 401, respectively. The end of the positive wire 402 away from the high-voltage power supply 401 is connected to the input nozzle 201a of the spinning nozzle 201, and the end of the negative wire 403 away from the high-voltage power supply 401 is connected to the collecting member 303. The high-voltage power supply 401 is used for power supply, and the positive wire 402 and the negative wire 403 are used to apply voltage during the solution spinning process to form an electrostatic field to promote the drawing process of the spinning process and form qualified fiber filaments.

[0042] During use, the electrostatic spinning device is connected and the high-voltage power supply 401 is turned on, so that a working voltage is formed between the nozzle unit 200 and the collecting unit 300, and the prepared spinning solution is loaded into the liquid supply device 101, and the spinning solution is pumped into the spinning nozzle 201 by the metering pump 103; when the voltage rises to a certain value, the droplets in the metal needle 202 generate electric charges, and the spinning solution forms Taylor cone droplets under the stretching action of the electric field force and is ejected out, and the diameter of the jet after drawing is sharply reduced after solvent evaporation and jet splitting, and the jet reaching the collecting part 303 is basically solidified into fibers, and the charge it carries will also be rapidly dissipated by grounding; cross-distributed and randomly arranged nanofibers will be formed on the collecting part 303.

[0043] Example 2

[0044] Reference Figure 2 to Figure 6 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that the spinning nozzle 201 in this embodiment adopts a new three-dimensional curved surface space arrangement, which greatly optimizes the spatial electric field distribution between the needles, ensuring the jet density of the spinning equipment and reducing the electric field interference of different needle parts.

[0045] Specifically, the spinning nozzle 201 has a cavity 201b inside the tube body, and a needle interface 201c is opened in the side wall of the tube body, and the cavity needle interface 201c is connected to the cavity 201b; the axial ends of the tube body of the spinning nozzle 201 are smoothly transitioned; the metal needle 202 is installed in the needle interface 201c.

[0046] The needle interfaces 201c are arranged in a plurality of groups in an array with equal spacing along the axis direction of the spinning nozzle 201, and each group includes 4 needle interfaces 201c which are evenly distributed with equal arcs.

[0047] The installation spacing between adjacent metal needles 202 is 20 to 30 mm.

[0048] Further, the spinning nozzle 201 is a capsule-shaped metal tubular structure, which is hollow inside and is a chamber 201b for accommodating the spinning solution input by high pressure, and is a spinning solution channel, which continuously supplies the spinning solution to each needle interface 201c. The supply of the spinning solution is obtained from the liquid supply pipe 102 by the input nozzle 201a opened on the side wall of the nozzle end. The circular hollow structure is adopted to facilitate the spatial symmetrical array distribution of multiple needles. Compared with the one-dimensional linear arrangement and the two-dimensional array, the number of spinning needles can be increased in the unit curved surface space, which effectively improves the jet density, improves the production efficiency of nanofibers, and reduces the space occupied by the equipment. The smooth transition treatment at both ends of the hollow metal tube can reduce the field strength of the edge needles and is conducive to improving the uniformity of the electric field distribution at the needles. All components are connected by standard threads and are easy to disassemble, which solves the problems of easy blockage in the needle area, difficulty in replacing the needles, and difficulty in cleaning the pipeline.

[0049] Furthermore, a plurality of needle interfaces 201c are arrayed in the circumferential side wall of the spinning nozzle 201, and each group has a plurality of needle interfaces 201c distributed along the radial direction at equal arcs. In this embodiment, four needle interfaces 201c are preferably distributed at intervals of 90 degrees, so that the axial view is in the shape of a "cross".

[0050] Each needle interface 201c is equipped with a metal needle 202, and the two can be assembled by standard threading. When installed in the manner of this embodiment, the distance between the needles increases, the electric field interaction between the needles decreases, and the field strength of each needle tip increases accordingly. When the needle distance increases to a certain extent, the field strength distribution of each needle is close to the single needle distribution. A larger needle distance is conducive to obtaining a working electric field with a larger field strength and uniform distribution, but the jet density is low, which is not conducive to improving production efficiency. Therefore, after multiple experimental verifications, the preferred needle distance in this embodiment is 20-30mm.

[0051] After the spinning solution is sprayed to form fibers, a collecting unit 300 is required for better collection.

[0052] Specifically, the lifting member 301 includes a support seat 301a, a threaded rod 301b disposed on the top of the support seat 301a, a threaded drive assembly 301c disposed on the two threaded rods 301b, and a bearing plate 301d installed on the two threaded drive assemblies 301c. The lifting member 301 is used as a whole to form a lifting action, and the support seat 301a, the threaded rod 301b, the threaded drive assembly 301c and the bearing plate 301d are a common lifting structure form. This solution does not make too many restrictions, and existing lifting structures and equipment can be used.

[0053] The rotating member 302 includes a rotating motor 302a installed in the middle of the carrier plate 301d and a connecting rod 302b arranged on the output shaft of the rotating motor 302a. Similar to the lifting member 301, the rotating member 302 is mainly used to drive the collecting member 303 to rotate. The rotating motor 302a and the connecting rod 302b are installed in the middle of the carrier plate 301d. Similarly, the existing technology can be used to achieve this, and no further explanation is given here.

[0054] The collecting member 303 includes a supporting ring 303a, driving rollers 303b disposed in the inner and outer walls of the supporting ring 303a, a conveyor belt 303c in rolling contact with the driving rollers 303b, and a metal collecting net 303d disposed on the surface of the conveyor belt 303c.

[0055] The axial ring body of the support ring 303a has a notch K, and the inner and outer walls of the support ring 303a are both provided with mounting grooves C; the transmission rollers 303b are arranged at both axial ends of the mounting grooves C, and are arranged in pairs, with several groups evenly distributed.

[0056] The edge of the conveyor belt 303c is rollingly clamped between the pair of transmission rollers 303b, and the conveyor belt 303c passes through the gap K of the support ring 303a and is connected to the inside and outside of the support ring 303a.

[0057] A slot A is provided on the side wall of the conveyor belt 303c, and the metal collection net 303d is detachably connected to the surface of the conveyor belt 303c through the slot A.

[0058] Furthermore, in the collecting member 303, the supporting ring 303a is the main structure, and the inner and outer walls of the ring are provided with mounting grooves C for mounting the conveying roller 303b, and the transmission roller 303b is used for the rolling transmission of the transmission belt 303c. The metal collecting net 303d is installed on the surface of the conveying belt 303c to facilitate the receipt of the solidified fiber filaments.

[0059] The end of the connecting rod 302b away from the rotating motor 302a is connected to the top side wall of the support ring 303a, suspending the support ring 303a and driving the rotation of the collecting member 303a. The gap K in the ring body of the support ring 303a facilitates the conveyor belt 303c installed inside and outside the ring to form a single continuous structure, so that the metal collecting net 303d outside the ring that does not carry fiber filaments can be transferred to the inside of the ring, and the metal net carrying fiber filaments of specified thickness inside can be transferred to the outside of the ring, thereby realizing uninterrupted continuous production, greatly improving the production efficiency of nanofibers; at the same time, it can greatly reduce the situation of metal needle blockage caused by stopping the advancement of the spinning solution.

[0060] It should be noted that the driving roller 303b can be driven manually or electrically, which is not specifically limited here. The metal collection net 303d is detachably mounted on the surface of the conveyor belt 303c in the form of a card slot A, which can conveniently remove and collect the collected fiber filaments, thereby facilitating the collection process.

[0061] Under the action of the lifting member 301, the metal collecting net 303d can move in the vertical direction, so that the nanofibers produced by needles at different heights are arranged in an overlapping manner; and the rotation of the metal collecting net 303d in the horizontal direction will cause the nanofibers produced by needles at the same height but different horizontal positions to be arranged in an overlapping manner, thereby improving the uniformity of the nanofibers, solving the differences in nanofibers spun by different needles, and making the properties of the fiber membrane stable and controllable.

[0062] Example 3

[0063] Reference Figure 1 to Figure 6 , which is the third embodiment of the present invention, uses the electrospinning device in the above embodiments 1 and 2 to produce nanofibers, and the specific operations are as follows:

[0064] 1. Equipment assembly and debugging: Assemble the liquid supply unit 100, the nozzle unit 200, the collection unit 300 and the electric field unit 400 into a complete electrospinning device. Install the metal needle 202 into the needle interface 201a in the side wall of the spinning nozzle 201, wherein the inner diameter of the metal needle 202 ranges from 0.2 to 20 mm, to ensure that the spinning solution can stably flow to the needle tip.

[0065] The spinning nozzle 201 is fixed at the center of the circle inside the collecting part 303, and the distance between all metal needles 202 and the metal receiving net 303d is the same, and the distance from the needle to the receiving net is controlled to be 5-30cm. The supply pipeline of the spinning solution is adjusted to ensure that the flow rate of the spinning solution can be stably controlled to achieve accurate adjustment of the thickness of the nanofibers.

[0066] Connect the high voltage power supply 401 and conduct preliminary voltage and flow rate tests to ensure that the basic operation of the equipment meets the spinning requirements.

[0067] 2. Preparation of spinning solution: Select polymers suitable for electrospinning, such as polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyurethane (TPU), polymethyl methacrylate (PMMA), polylactic acid-co-glycolic acid (PLGA) and polycaprolactone (PCL), and adjust the concentration, viscosity and conductivity of the polymer solution according to the desired nanofiber properties. Use appropriate solvents, such as organic solvents such as dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and tetrahydrofuran (THF), to dissolve the polymer and stir it thoroughly for 12-24 hours until a uniform spinning solution is formed.

[0068] 3. Equipment operation and parameter setting: Start the metering pump 103 and adjust it to a predetermined flow rate, so that the spinning solution is delivered to the spinning nozzle 201 and the metal needle 202 at a stable speed, and ensure that the flow rate of a single needle is stable at 0.5-2.0 ml / h. At the same time, adjust the voltage of the high-voltage power supply 401 to 5-30 kV, gradually increase it to generate a stable electric field, and ensure that a uniform working voltage is formed between the metal needle 202 and the collecting member 303. By observing the shape change of the droplet at the metal needle 202, it is judged whether the voltage reaches the critical value and forms a stable Taylor cone.

[0069] The spinning solution is ejected from the metal needle 202 under the action of the electric field force. The diameter and shape of the nanofibers can be fine-tuned by adjusting the voltage and flow rate.

[0070] 4. Operation of the collector: Operate the lifting member 301 and the rotating member 302 to control the collecting member 303, and adjust its vertical position and horizontal rotation speed to achieve uniform distribution of nanofibers on the metal collecting net 303d. By changing the vertical movement range of the collecting member 303, the uniformity of the fiber layer can be controlled; by adjusting the rotation speed, the orientation of the fiber can be affected, thereby preparing a nanofiber membrane with a specific orientation structure. After the inner metal net collects the nanofiber membrane of a specified thickness, the conveyor belt 303c is controlled to rotate and the inner metal net is transferred to the outer layer to facilitate the collection of the nanofiber membrane. Synchronously, the outer metal net continues to collect nanofibers after entering the interior. The reciprocating cycle of the inner and outer metals can realize the batch collection of nanofiber membranes. The lifting range is: 0-6cm, and the lifting speed range is: 0-100cm / min. The horizontal rotation speed range is: 0-1000rpm, and the conveyor belt speed is: 0-10m / min.

[0071] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An electrospinning device for industrial preparation of nanofibers, characterized in that: include, A liquid supply unit (100), comprising a liquid supply device (101), a liquid supply pipe (102) having one end connected to an output end of the liquid supply device (101), and a metering pump (103) connected to the liquid supply pipe (102); A nozzle unit (200) comprises a spinning nozzle (201) and a metal needle (202) arranged on the spinning nozzle (201), wherein one end of the liquid supply pipe (102) away from the liquid supply device (101) is connected to an input pipe opening (201a) of the spinning nozzle (201); and a collecting unit (300) disposed on the circumferential outer side of the nozzle unit (200), comprising a lifting member (301), a rotating member (302) mounted on the lifting member (301), and a collecting member (303) connected to an output end of the rotating member (302) and suspended between the supporting frames (301); and, The electric field unit (400) comprises a high-voltage power supply (401) and a positive electrode wire (402) and a negative electrode wire (403) respectively connected to the positive electrode and the negative electrode of the high-voltage power supply (401), wherein one end of the positive electrode wire (402) away from the high-voltage power supply (401) is connected to an input nozzle (201a) of a spinning nozzle (201), and one end of the negative electrode wire (403) away from the high-voltage power supply (401) is connected to a collecting member (303).

2. The electrospinning device for industrial preparation of nanofibers according to claim 1, characterized in that: The spinning nozzle (201) has a cavity (201b) inside the tube body, and a needle interface (201c) is provided in the side wall of the tube body, and the cavity needle interface (201c) is connected to the cavity (201b); The spinning nozzle (201) has two axial ends of the tube body subjected to smooth transition treatment; The metal needle (202) is installed in the needle interface (201c).

3. The electrospinning device for industrial preparation of nanofibers according to claim 2, characterized in that: The needle interfaces (201c) are arranged in a plurality of groups in an array at equal intervals along the axis direction of the spinning nozzle (201), and each group includes four needle interfaces that are evenly distributed with equal arcs.

4. The electrospinning device for industrial preparation of nanofibers according to claim 3, characterized in that: The installation spacing between adjacent metal needles (202) is 20 to 30 mm.

5. The electrospinning device for industrial preparation of nanofibers according to claim 4, characterized in that: The lifting member (301) comprises a support seat (301a), a threaded rod (301b) arranged on the top of the support seat (301a), a threaded drive assembly (301c) arranged on the two threaded rods (301b), and a bearing plate (301d) installed on the two threaded drive assemblies (301c).

6. The electrospinning device for industrial preparation of nanofibers according to claim 5, characterized in that: The rotating member (302) comprises a rotating motor (302a) installed in the middle of the bearing plate (301d) and a connecting rod (302b) arranged on the output shaft of the rotating motor (302a).

7. The electrospinning device for industrial preparation of nanofibers according to claim 6, characterized in that: The collecting member (303) comprises a supporting ring (303a), a transmission roller (303b) arranged in the inner and outer walls of the supporting ring (303a), a conveyor belt (303c) in rolling contact with the transmission roller (303b), and a metal collecting net (303d) arranged on the surface of the conveyor belt (303c).

8. The electrospinning device for industrial preparation of nanofibers according to claim 7, characterized in that: The axial ring body of the support ring (303a) has a notch (K), and the inner side wall and the outer side wall of the support ring (303a) are both provided with a mounting groove (C); The transmission rollers (303b) are arranged at both axial ends of the installation groove (C) and are arranged in pairs, with a plurality of groups evenly distributed.

9. The electrospinning device for industrial preparation of nanofibers according to claim 8, characterized in that: The edge of the conveyor belt (303c) is rollingly clamped between the pair of transmission rollers (303b), and the conveyor belt (303c) passes through the gap (K) of the support ring (303a) and is connected to the inside and outside of the support ring (303a).

10. The electrospinning device for industrial preparation of nanofibers according to claim 9, characterized in that: A slot (A) is provided on the side wall of the conveyor belt (303c), and the metal collection net (303d) is detachably connected to the surface of the conveyor belt (303c) via the slot (A).

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