A free surface electrospinning device

Abstract

The application relates to a free liquid surface type electrostatic spinning device which comprises a high-voltage generator, two supporting frames, a liquid drop platform, a plurality of groups of jet flow generating devices, a collecting plate and a liquid supply device; the two supporting frames are symmetrically fixed on the high-voltage generator; the liquid drop platform is slidingly installed between the two supporting frames, and the top surface of the liquid drop platform is provided with a plurality of grooves; the plurality of groups of jet flow generating devices are arranged between the two supporting frames and correspond to the plurality of grooves; the collecting plate is arranged directly above the plurality of groups of jet flow generating devices; and the liquid supply device is connected with a liquid inlet pipeline. After the spinning liquid drops from the liquid outlet pipeline, the spinning liquid falls on the metal wires to form free liquid surfaces; under the action of the electric field between the metal wires and the collecting plate, a large range of nanometer and micrometer fibers are deposited on the collecting plate, the amount of spun yarn is large, the production efficiency is high, a relatively long distance can be ensured between the metal wires to avoid the interference of the electric field, and the stability of fiber forming and spinning is ensured.

Description

Technical Field

[0001] This invention belongs to the field of electrospinning technology, and in particular relates to a free-liquid-surface electrospinning device. Background Technology

[0002] Electrospinning is a common method for preparing micro and nanofibers. It is simple to operate and can impart different properties and functions to micro-electrospun nanofibers depending on the selected spinning solution formulation. Micro and nanofibers prepared by electrospinning possess advantages such as specific surface area, controllable morphology, fine structure, and replaceable components, making them widely applicable in filtration, adsorption, sensors, energy storage, medical applications, and catalysis. Currently, most electrospinning processes use single needles, resulting in low production efficiency (only 0.1–1 g / h) and needle clogging, requiring regular cleaning, which significantly limits its industrial application.

[0003] To address the aforementioned issues, current solutions primarily involve replacing the single needle in the jet generator with a multi-needle design, increasing the number of needles to improve spinning efficiency. Chinese patents CN201811114850.9, CN202011163131.3, CN202210758083.5, and CN201910566867.6 disclose electrospinning devices for mass production of nanofibers using arrayed multi-needle designs. However, with the increase in the number of needles, the electric field interference at the needle tips becomes more pronounced, affecting fiber formation and spinning stability. Furthermore, the multi-needle design still suffers from needle clogging, requiring periodic shutdowns for cleaning, significantly impacting production efficiency. Summary of the Invention

[0004] The main objective of this invention is to provide a free-float electrospinning device that can effectively solve the problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A free-liquid-surface electrospinning device, comprising

[0007] High voltage generator;

[0008] Two support frames are symmetrically fixed to the high-voltage generator;

[0009] A dripping platform is slidably mounted between the two support frames, and the top surface of the dripping platform has several grooves;

[0010] Several sets of jet generating devices are arranged between two support frames and corresponding to several grooves. The jet emitter includes two metal wires and an electric three-way valve. The two metal wires are threaded through the corresponding grooves, and their two ends are fixedly connected to the two support frames and to the electrodes of the high-pressure generator. The electric three-way valve is fixed at the top of the corresponding groove and is connected to two liquid outlet pipes and one liquid inlet pipe. The outlets of the two liquid outlet pipes are located directly above the two metal wires.

[0011] A collection plate is positioned directly above the plurality of jet generating devices;

[0012] A liquid supply device, connected to the liquid inlet pipe, is used to provide spinning solution.

[0013] Preferably, support rods are fixed at the bottom of both ends of the dripping platform, and the bottom of the support rods is slidably connected to the side of the high-pressure generator via slide rails.

[0014] Preferably, the liquid supply device includes

[0015] Spinning solution container, used to store spinning solution;

[0016] Several suction pumps are provided, with their inlets connected to the spinning solution container via pipes and their outlets connected to the corresponding inlet pipes via pipes.

[0017] Preferably, the front and rear sides of the dripping platform are provided with a plurality of scraping self-cleaning devices, which correspond to the plurality of metal wires and are used to scrape off the residue on the metal wires. The scraping self-cleaning device corresponding to the first metal wire in each group of jet generating devices is located on the rear side of the dripping platform, and the scraping self-cleaning device corresponding to the second metal wire in each group of jet generating devices is located on the front side of the dripping platform.

[0018] Preferably, the scraper self-cleaning device includes

[0019] A mounting base is fixed to the side of the dripping platform. The side of the mounting base has a mounting groove, through which the metal wire passes. A collection groove is formed on the bottom surface of the mounting groove, directly below the metal wire.

[0020] The lifting control assembly is fixed to the top surface of the mounting slot;

[0021] The scraper is located directly above the metal wire and is connected to the bottom of the lifting control component. The lifting and lowering can be controlled by the lifting control component. The bottom of the scraper has an arc-shaped opening that is adapted to the metal wire.

[0022] Preferably, the lifting control component is an electromagnet.

[0023] Preferably, it also includes a recycling device, the recycling device comprising...

[0024] Residue collection container;

[0025] Several recycling tubes are connected at one end to the residue collection container and at the other end to the bottom of the corresponding collection tank.

[0026] This invention provides a free-liquid-surface electrospinning device, which has the following beneficial effects:

[0027] 1. After the spinning solution drips from the outlet pipe, it falls onto the metal wire to form a free liquid surface. Under the action of the electric field between the metal wire and the collecting plate, the liquid surface forms a large number of jets and moves towards the collecting plate. Then, it is stretched and refined into nanofibers and finally deposited on the collecting plate. With the reciprocating motion of the dripping platform, the spinning solution is supplied evenly and continuously drips onto the metal wire, resulting in a large area of ​​nanofiber deposition on the collecting plate. The output is large and the production efficiency is high. In addition, the distance between each metal wire can be maintained to avoid the interference of the electric field and ensure the stability of fiber forming and spinning.

[0028] 2. Under the reciprocating motion of the dripping platform, the scraper and the electric three-way valve work together to continuously generate nanofibers that are deposited on the collection plate. Before the spinning solution drips onto the metal wire, the scraper can scrape off the residue and drop it into the collection tank, ensuring the cleanliness of the metal wire surface. This ensures the quality of the microfibers and eliminates the need for manual cleaning, further improving production efficiency. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the free liquid surface electrospinning device of the present invention;

[0030] Figure 2 For the present invention Figure 1 Enlarged view of point A in the middle.

[0031] In the diagram: 1. High-pressure generator; 2. Support frame; 3. Drip platform; 31. Groove; 4. Jet generator; 41. Metal wire; 42. Electric three-way valve; 43. Outlet pipe; 44. Inlet pipe; 5. Collection plate; 6. Liquid supply device; 61. Spinning solution container; 62. Suction pump; 7. Support rod; 8. Slide rail; 9. Self-cleaning scraper; 91. Mounting base; 911. Mounting groove; 912. Collection groove; 92. Lifting control assembly; 93. Scraper; 10. Residue collection container; 11. Recovery pipe. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Example 1

[0037] Reference Figure 1-2 A free-liquid-surface electrospinning device, comprising:

[0038] High voltage generator 1, externally connected to a positive voltage of 45kV;

[0039] Two support frames 2 are symmetrically fixed on the high voltage generator 1;

[0040] The dripping platform 3 is slidably installed between the two support frames 2 and can move back and forth at a speed of 10m / min. The top surface of the dripping platform 3 has several grooves 31.

[0041] Several sets of jet generating devices 4 are arranged between two support frames 2 and correspond to several grooves 31. Each jet emitter includes two metal wires 41 and an electric three-way valve 42. The two metal wires 41 are threaded through the corresponding grooves 31, and their two ends are fixedly connected to the two support frames 2 and to the electrodes of the high-voltage generator 1. It should be noted that the electrodes of the high-voltage generator 1 are located inside the support frame 2, and the electrodes are connected to the metal wires 41 inside the support frame 2. In this embodiment, the number of jet generating devices 4 is 6 sets. There are 12 wires 41 in total. The material of the metal wires 41 can be stainless steel, tungsten, copper, etc. The length of the metal wires 41 is 1.2m and the cross-section is a circle with a diameter of 3mm. The electric three-way valve 42 is fixed on the top of the corresponding groove 31. The electric three-way valve 42 is connected to two liquid outlet pipes 43 and one liquid inlet pipe 44. The outlets of the two liquid outlet pipes 43 are located directly above the two metal wires 41. The diameters of the liquid inlet pipe 44 and the liquid outlet pipe 43 are 1cm and 0.5cm, respectively. The dripping height of the liquid outlet pipe 43 is 0.8cm.

[0042] The collecting plate 5 is positioned directly above the plurality of jet generating devices 4. The collecting plate 5 is grounded and is used to form an electric field with the metal wire 41.

[0043] The liquid supply device 6 is connected to the liquid inlet pipe 44 and is used to supply spinning solution.

[0044] When this device is in use, the high-voltage generator 1 starts up to provide the voltage required for spinning the metal wire 41. An electric field is formed between the metal wire 41 and the collecting plate 5. After the liquid supply device 6 provides spinning solution to the inlet pipe 44, the spinning solution drips from the outlet pipe 43 after passing through the electric three-way valve 42. The electric three-way valve 42 can control the simultaneous dripping of both outlet pipes 43 or control the dripping of any one outlet pipe 43, as needed. After the spinning solution drips from the outlet pipe 43, it falls onto the metal wire 41 to form a free liquid surface. Under the influence of the electric field between the metal wire 41 and the collecting plate 5, a large number of jets are formed on the liquid surface and move toward the collecting plate 5. Then, they are stretched and refined into nanofibers and finally deposited on the collecting plate 5. With the reciprocating motion of the dripping platform 3, the spinning solution is supplied evenly and continuously drips onto the metal wire 41, resulting in a large area of ​​nanofiber deposition on the collecting plate 5. The output is large and the production efficiency is high. In addition, the distance between each metal wire 41 can be maintained to avoid the interference of the electric field and ensure the stability of fiber forming and spinning.

[0045] In one specific implementation, a sliding installation structure for a dripping platform 3 is provided. Support rods 7 are fixed at the bottom of both ends of the dripping platform 3. The bottom of the support rods 7 is slidably connected to the side of the high-pressure generator 1 through a slide rail 8. Under the action of the slide rail 8, the dripping platform 3 can move back and forth. Preferably, the dripping platform 3 can be driven by a motor.

[0046] In one specific implementation, the liquid supply device 6 includes

[0047] Spinning solution container 61, used to store spinning solution;

[0048] Several suction pumps 62 have their inlets connected to the spinning solution container 61 via pipes (not shown), and their outlets connected to the corresponding liquid inlet pipes 44 via pipes (not shown). The suction pumps 62 have a working power of 350W and can transport the spinning solution in the spinning solution container 61 to the electric three-way valve 42.

[0049] In this embodiment, a mounting plate is fixedly connected between the two support rods 7, which can improve the stability of the two support rods 7. The spinning solution container 61 and the suction pump 62 can also be easily installed on the mounting plate.

[0050] Example 2

[0051] After the device has been running for a period of time, the spinning solution dripping onto the metal wire 41 may produce viscous residues due to solvent evaporation and failure to expel the fibers in time, affecting production and requiring machine shutdown for manual cleaning, which will impact production efficiency. Therefore, to further improve production efficiency, a further design can be made based on the structure of Example 1, as follows:

[0052] The dripping platform 3 is provided with a plurality of scraping self-cleaning devices 9 on its front and rear sides. These scraping self-cleaning devices 9 correspond to a plurality of metal wires 41 and are used to scrape away residue from the metal wires 41. Specifically, the scraping self-cleaning device 9 corresponding to the first metal wire 41 in each group of jet generating devices 4 is located on the rear side of the dripping platform 3, and the scraping self-cleaning device 9 corresponding to the second metal wire 41 in each group of jet generating devices 4 is located on the front side of the dripping platform 3. Figure 2 The first metal wire is on the left and the second metal wire is on the right.

[0053] In one specific implementation, the scraper self-cleaning device 9 includes

[0054] Mounting base 91 is fixed to the side of the dripping platform 3. Mounting base 91 has a mounting groove 911 on its side. The metal wire 41 passes through the mounting groove 911. A collection groove 912 is formed on the bottom surface of the mounting groove 911 directly below the metal wire 41. The collection groove 912 is a quadrilateral container with dimensions of 2cm × 5cm × 2cm.

[0055] The lifting control assembly 92 is fixed to the top surface of the mounting slot 911;

[0056] The scraper 93 is located directly above the metal wire 41 and is connected to the bottom of the lifting control component 92. The lifting and lowering can be controlled by the lifting control component 92. The bottom of the scraper 93 has an arc-shaped opening that is adapted to the metal wire 41.

[0057] Based on the above, the present invention also provides a method for using a free-liquid-surface electrospinning device, comprising the following steps:

[0058] S1: Dissolve the polymer in an organic solvent, stir evenly to obtain a spinning solution, and place the spinning solution in a spinning solution container 61;

[0059] S2: In the initial state, the dripping platform 3 is close to the front support frame 2. After the device is started, the dripping platform 3 begins to move backward. At the same time, the scraper 93 above the first metal wire 41 in the jet generating device 4 descends under the control of the lifting control component 92. Its arc opening fits with the metal wire 41. The suction pump 62 delivers the spinning solution to the electric three-way valve 42. The electric three-way valve 42 controls the flow direction, causing the liquid outlet pipe 43 above the first metal wire 41 in the jet generating device 4 to drip. In this way, before the spinning solution drips onto the first metal wire 41, the scraper 93 has already cleaned the surface of the metal wire 41.

[0060] S3: When the dripping platform 3 reaches the farthest end and begins to move in the opposite direction, the scraper 93 above the second metal wire 41 in the jet generating device 4 descends under the control of the lifting control component 92, and its arc opening fits against the metal wire 41. Meanwhile, the scraper 93 above the first metal wire 41 rises under the control of the lifting control component 92, detaches from the surface of the metal wire 41, and the electric three-way valve 42 controls the flow direction, causing the liquid outlet pipe 43 above the second metal wire 41 in the jet generating device 4 to drip liquid. Similarly, before the spinning solution drips onto the second metal wire 41, the scraper 93 has already cleaned the surface of the metal wire 41.

[0061] S4: After the dripping platform 3 has reciprocated for several cycles, preferably 3-5 cycles, start the high-voltage generator 1 and adjust the voltage until an umbrella-shaped jet profile is formed on the surface of the metal wire 41 without dripping. Under the reciprocating motion of the dripping platform 3, the scraper 93 and the electric three-way valve 42 work together to continuously generate nanofibers that are deposited on the collection plate 5. Before the spinning solution drips onto the metal wire 41, the scraper 93 can scrape off the residue and drop it into the collection tank 912, ensuring the cleanliness of the surface of the metal wire 41. This ensures the quality of the microfibers and eliminates the need for manual cleaning, further improving production efficiency.

[0062] In one specific implementation, the lifting control component 92 is an electromagnet, which is controlled by a circuit switch to realize the attraction and separation of the scraper 93 from the electromagnet, that is, the lifting and lowering of the scraper 93.

[0063] In one specific implementation, a recycling device is also included, the recycling device comprising:

[0064] Residue collection container 10;

[0065] Several recycling tubes 11 are connected at one end to the residue collection container 10 and at the other end to the bottom of the corresponding collection tank 912. The recycling tubes can use a negative pressure suction system to suck the residue in the collection tank 912 into the residue collection container 10 for overall collection, which facilitates subsequent recycling processing.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of using a free-liquid-surface electrospinning device, characterized in that... The device includes a free-float electrospinning apparatus, wherein the free-float electrospinning apparatus comprises: High voltage generator; Two support frames are symmetrically fixed to the high-voltage generator; A dripping platform is slidably mounted between the two support frames, and the top surface of the dripping platform has several grooves; Several sets of jet generating devices are arranged between the two support frames and correspond to the several grooves. Each jet generating device includes two metal wires and an electric three-way valve. The two metal wires are threaded through the corresponding grooves. In the middle, both ends are fixedly connected to the two support frames respectively, and are connected to the electrodes of the high-voltage generator, the electric... The three-way valve is fixed to the top of the corresponding groove. The electric three-way valve is connected to two outlet pipes and one inlet pipe. The outlets of the two liquid outlet pipes are respectively located directly above the two metal wires; A collection plate is positioned directly above the plurality of jet generating devices; A liquid supply device, connected to the liquid inlet pipe, is used to provide spinning solution; The front and rear sides of the dripping platform are equipped with several self-cleaning scraping devices, which are connected to... Several corresponding metal wires are used to scrape off residues from the metal wires, among which, the first wire in each group of jet generating devices The corresponding scraping self-cleaning device for the metal wire is located on the rear side of the dripping platform, and is connected to the second wire in each group of jet generating devices. The corresponding scraping and self-cleaning device for the metal wire is located on the front side of the dripping platform; The scraper self-cleaning device includes A mounting base is fixed to the side of the dripping platform. The side of the mounting base has a mounting groove from which the metal wire... The wire passes through the mounting groove, and a collection groove is provided on the bottom surface of the mounting groove directly below the metal wire; The lifting control assembly is fixed to the top surface of the mounting slot; The scraper, located directly above the metal wire, is connected to the bottom of the lifting control assembly and can be controlled by the lifting control assembly. The lifting mechanism is controlled by a component, and the bottom of the scraper has an arc-shaped opening that is adapted to the metal wire. It also includes the following steps: S1: Dissolve the polymer in an organic solvent, stir evenly to obtain a spinning solution, and place the spinning solution in a spinning solution container; S2: In its initial state, the dripping platform is close to the front support frame. After the device is started, the dripping platform begins to move backward. At the same time, the scraper above the first metal wire in the jet generator descends under the control of the lifting control component. Its arc opening fits against the metal wire. The suction pump delivers the spinning solution to the electric three-way valve. The electric three-way valve controls the flow direction, causing the liquid outlet pipe above the first metal wire in the jet generator to drip. In this way, the scraper cleans the surface of the metal wire before the spinning solution drips onto it. S3: When the dripping platform reaches the farthest end and begins to move in the opposite direction, the scraper above the second metal wire in the jet generator descends under the control of the lifting control component, and its arc opening fits against the metal wire. Meanwhile, the scraper above the first metal wire rises under the control of the lifting control component, detaches from the surface of the metal wire, and the electric three-way valve controls the flow direction, causing the liquid outlet pipe above the second metal wire in the jet generator to drip liquid. Similarly, before the spinning solution drips onto the second metal wire, the scraper has already cleaned the surface of the metal wire. S4: After the dripping platform has reciprocated for several cycles, the high-voltage generator is started and the voltage is adjusted until an umbrella-shaped jet profile is formed on the surface of the metal wire without dripping. Under the reciprocating motion of the dripping platform, the scraper and the electric three-way valve work together to continuously generate nanofibers that are deposited on the collection plate. Before the spinning solution drips onto the metal wire, the scraper can scrape off the residue and put it into the collection tank, ensuring the cleanliness of the metal wire surface. This ensures the quality of the microfibers and eliminates the need for manual cleaning, further improving production efficiency.

2. The method of using the free-liquid-surface electrospinning device according to claim 1, characterized in that: The bottom of both ends of the dripping platform is fixed with support rods, and the bottom of the support rods is slidably connected to the side of the high-pressure generator via slide rails.

3. The method of using the free-liquid-surface electrospinning device according to claim 1, characterized in that: The liquid supply device includes Spinning solution container, used to store spinning solution; Several suction pumps are provided, with their inlets connected to the spinning solution container via pipes and their outlets connected to the corresponding inlet pipes via pipes.

4. The method of using the free-liquid-surface electrospinning device according to claim 1, characterized in that: The lifting control component is an electromagnet.

5. The method of using the free-liquid-surface electrospinning device according to claim 1, characterized in that: It also includes a recycling device, the recycling device comprising... Residue collection container; Several recycling tubes are connected at one end to the residue collection container and at the other end to the bottom of the corresponding collection tank.

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