Needleless electrospinning device

Abstract

The utility model discloses a needleless electrospinning device, including frame body, wire electrode, straddling to be arranged on the frame body, coating device, the electric field stabilization device that can slide to be arranged on wire electrode and be connected with liquid supply device, including metal ring and the connecting piece of connecting metal ring with wire electrode, and the metal ring ring body is horizontally arranged below wire electrode. The utility model discloses an electric field stabilization device is set up to optimize the electric field in the electrospinning process, and specifically speaking is to increase a larger metal ring in wire electrode lower extreme to provide an additional electric field, and the electric field force is used to control the jet instability in the spinning process, and the interference of adjacent wire electrode electric field to it is reduced to the quality of product is improved. The additional electric field of increase is also favorable to the further excitation of jet, and the quality is ensured to further increase the output.

Description

Technical Field

[0001] This utility model relates to a needleless electrospinning device. Background Technology

[0002] With the development of modern technology, researchers have placed increasingly higher demands on material properties. Among the rapidly developing and widely used materials, nanofibers, due to their large specific surface area and high porosity, as well as the surface effects, quantum size effects, quantum tunneling effects, and dielectric effects characteristic of nanomaterials, have been widely applied in fields such as filtration, biomedicine, sensors, and catalysts, showing great promise for development. Currently, there are many methods for preparing nanofibers, such as stretching, template synthesis, phase separation, and electrospinning. The first three methods are still at the laboratory level due to poor process controllability. Electrospinning technology, due to its low cost, simple process, and wide range of spinnable polymers, has attracted increasing attention from researchers.

[0003] Traditional needle-type electrospinning mainly consists of a nozzle, a high-voltage generator, and a receiving device. Under an applied high-voltage electric field, the polymer solution forms a suspended cone-shaped droplet at the nozzle tip. When the electrostatic repulsion on the droplet surface exceeds its surface tension, the droplet is ejected at high speed to form a jet. The jet is further stretched to form nanofibers, which are eventually deposited on the receiving device. With technological advancements, needle-type electrospinning faces limitations in production capacity. Furthermore, due to the small diameter of the needles, the polymer solution is prone to solidification after prolonged spinning due to solvent evaporation and water absorption, leading to needle blockage and hindering stable long-term production.

[0004] Needleless nozzles are well-suited for mass production due to their numerous excitation points, high output, and ease of cleaning after use. A reference can be made to an electrospinning device disclosed in Chinese Utility Model Patent Application No. 202420924854.8, which includes a frame, a wire electrode, a coating device, and a liquid collection tank. The wire electrode is mounted across the frame, the coating device is slidably mounted on the wire electrode and connected to a liquid supply device, and the liquid collection tank is located at the bottom of the frame to collect unexcited spinning liquid that slides off the wire electrode.

[0005] Conventional reciprocating wire electrodes, being entirely exposed metal, have an unstable excitation point during spinning, leading to an unstable jet and affecting the quality of the prepared fiber membrane. Furthermore, mutual interference between adjacent electrode wires due to the electric field further exacerbates the instability of the electrospinning jet. Chinese invention patent application 202411725614.6 discloses a free-float electrospinning device that reduces the mutual influence between electric fields by lengthening the distance between two electrode wires; however, this approach results in reduced yield and fails to maximize the advantages of needle-free nozzles.

[0006] To address this problem, some solutions have been proposed in the existing technology, but some issues still remain.

[0007] (1) Add bumps or other spinning excitation structures to the smooth wire electrode to fix the electrospinning excitation sites on the wire electrode and reduce the jet instability caused by the uncertainty of the excitation point. However, the electrode wire is thin and the processing technology is difficult. In addition, the creation of excitation points will also lead to a reduction in the yield of nanofibers.

[0008] (2) Adding a baffle between the two electrode wires can reduce the mutual interference between the electrode wires, but its structure is complicated and the baffle will cause some of the fibers to stick together, resulting in a decrease in production.

[0009] (3) Airflow is used at the lower end to reduce the disturbance of nanofibers, but because nanofibers are light, they will be carried away by the airflow to a certain extent, resulting in nanofiber loss. Utility Model Content

[0010] The first technical problem to be solved by this utility model is to propose a needleless electrospinning device that can keep the excitation jet stable, in light of the above-mentioned technical status.

[0011] The second technical problem to be solved by this utility model is to propose a needleless electrospinning device that can increase the yield of nanofibers, in light of the above-mentioned current technical situation.

[0012] The technical solution adopted by this utility model to solve the above two technical problems is: a needleless electrospinning device, comprising...

[0013] Frame;

[0014] Wire electrodes are mounted across the frame.

[0015] The coating device is slidably mounted on the online electrode and connected to the liquid supply device;

[0016] Its characteristic is that it also includes

[0017] An electric field stabilizing device includes a metal ring and a connector that connects the metal ring to a line electrode, with the metal ring horizontally positioned below the line electrode.

[0018] Preferably, the device includes a plurality of wire electrodes and a metal ring corresponding to the number of wire electrodes, with a metal ring disposed below each wire electrode.

[0019] Preferably, the metal ring includes two straight first ring portions parallel to the wire electrodes, and a second ring portion extending from the ends of the first ring portions and connecting the two parallel first ring portions to form a ring. The second ring portion may be arc-shaped or straight-shaped similar to the first ring portions.

[0020] Preferably, the two first ring body parts are located on both sides of their corresponding line electrodes and are equidistant from the line electrodes.

[0021] To facilitate the fixing of the metal ring and the wire electrode, preferably, the connector is integrally formed with the metal ring. The connector extends vertically upward from the center of the second ring body of the metal ring, and its end is provided with a connecting hole. The connector is sleeved on the wire electrode through the connecting hole.

[0022] To prevent the metal ring from slipping, preferably, the needleless electrospinning device also includes a limiting member with a limiting hole. The limiting member is sleeved and fixed to the wire electrode through the limiting hole and is closely disposed on the outside of the connector.

[0023] To simplify the structure and reduce costs, as a preferred option, the needleless electrospinning device also includes a high-voltage generator, wherein the electric field stabilizing device and the wire electrode share the same high-voltage generator.

[0024] Preferably, the coating device includes a sliding member with a coating hole, the sliding member being sleeved on the wire electrode through the coating hole, and the coating device also includes a liquid infusion tube, one end of which is connected to a liquid supply device, and the other end of which is connected to the coating hole and supplies spinning solution to the coating hole.

[0025] To collect the unexcited spinning solution that slips off the wire electrode, preferably, the needleless electrospinning device further includes a liquid collection tank, which is located at the bottom of the frame and below the wire electrode.

[0026] To stably mount the wire electrode, preferably, the frame includes a horizontal base plate and two opposing vertical side plates. The upper end of the side plates is provided with a fixing ring, and the two ends of the wire electrode are respectively inserted into the fixing rings of the two side plates and thus straddle the frame.

[0027] Compared with existing technologies, this invention optimizes the electric field during electrospinning by setting up an electric field stabilization device. Specifically, a large metal ring is added to the lower end of the online electrode to provide an additional electric field. This electric field force controls the instability of the jet during spinning and reduces interference from the electric fields of adjacent online electrodes, thereby improving product quality. The added extra electric field also facilitates further jet excitation, increasing production while ensuring quality. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0029] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0030] Figure 3 This is a top-view schematic diagram of an embodiment of the present utility model;

[0031] Figure 4 This is a schematic diagram of the electric field stabilization device according to an embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] like Figures 1-4 The diagram shows a preferred embodiment of the needleless electrospinning device of this invention. This embodiment includes a frame 1, a wire electrode 2, a coating device 3, a liquid collection tank 4, and an electric field stabilizing device 5. The frame 1 supports and mounts the other structures. The wire electrode 2 is used for electrospinning. The coating device 3 continuously coats the wire electrode 2 with spinning solution. The spinning solution on the wire electrode 2 is excited to form nanofibers, which are deposited on a receiving substrate positioned above the needleless electrospinning device. The liquid collection tank 4 is located at the bottom of the frame 1 and collects the unexcited spinning solution that slips off the wire electrode 2. The electric field stabilizing device 5 forms an auxiliary electric field, reducing instability in the excitation process on the wire electrode 2, improving the quality of the fiber membrane, and the additional electric field further accelerates the nanofiber excitation speed, thereby increasing the yield of the nanofiber membrane.

[0034] The specific structure of this embodiment is as follows: Figure 1 As shown, the frame 1 includes a horizontal base plate and two opposing vertical side plates. A short column 11 is provided at the upper end of each side plate, and the column 11 has a fixing hole 11. The two ends of the wire electrode 2 are respectively inserted into the fixing holes 11 of the two side plates, thus spanning the frame 1. In this embodiment, a total of four parallel and evenly spaced wire electrodes 2 are spanned on the frame 1. The wire electrodes 2 have a diameter of 0.8 mm and can stimulate spinning under high pressure.

[0035] The coating device 3 is slidably mounted on the wire electrode 2 and includes a sliding member 31 and a liquid delivery tube 32. The sliding member 31 has a coating hole 311 and is fitted onto the wire electrode 2 through the coating hole 311. One end of the liquid delivery tube 32 is connected to a liquid supply device that provides spinning solution, and the other end is connected to the coating hole 311 and continuously supplies spinning solution to the coating hole 311. The diameter of the coating hole 311 is larger than the diameter of the wire electrode 2. In this embodiment, its diameter is designed to be 1.2 mm and its stroke is designed to be 0.8 m. By sliding back and forth, the spinning solution on the wall of the coating hole 311 is coated onto the surface of the wire electrode 2.

[0036] like Figure 1 and Figure 3As shown, the electric field stabilizing device 5 includes a metal ring 51 and a connector 52. The metal ring 51 provides an auxiliary electric field and is horizontally positioned below the line electrode 2. The connector 52 connects the metal ring 51 to the line electrode 2. The number of metal rings 51 is the same as that of the line electrodes 2, which is four in total. One metal ring 51 is positioned below each line electrode 2. The diameter of the metal ring 51 is 6 mm. The metal ring 51 includes two straight first ring portions 511 parallel to the line electrode 2, and a second ring portion 512 extending from the ends of the first ring portions 511 and connecting the two parallel first ring portions 511 into a ring. The length of the first ring portion 511 is 1 m, and the second ring portion 512 is also straight in this embodiment, with a length of 0.15 m. The two first ring portions 511 are located on both sides of their corresponding line electrode 2, and the height difference between them and the line electrode 2 is 8 cm.

[0037] like Figure 2 and Figure 4 As shown, the connector 52 is integrally formed with the metal ring 51 and is also made of metal. It extends vertically upward from the center of the second ring body 512 of the metal ring 51, and has a connecting hole 521 at its end with a diameter of 0.8 mm. The connector 52 is fitted onto the wire electrode 2 through the connecting hole 521. To prevent the metal ring 51 from sliding, this embodiment also provides a limiting buckle as a limiting member 6, which has a limiting hole. The limiting member 6 is fitted and fixed onto the wire electrode 2 through the limiting hole and is tightly disposed on the outside of the connector 52, thereby limiting the position of the electric field stabilizing device 5.

[0038] In this embodiment, both the line electrode 2 and the electric field stabilizing device 5 need to be connected to a high-voltage generating device. To simplify the structure and reduce costs, the electric field stabilizing device 5 and the line electrode 2 can share the same high-voltage generating device.

[0039] To facilitate comparison of the quality of fiber membranes spun by this embodiment and conventional wire electrodes, this embodiment measures the quality of the fiber membrane by counting the number of defects per square meter of fiber membrane surface.

[0040] Production Calculation: Electrospinning was performed using four wire electrodes (2), with PET nonwoven fabric as the receiving substrate. Before spinning, the basis weight (g / m³) of the nonwoven fabric was weighed using a precision balance. 2 After spinning, the total basis weight (g / m³) of the nonwoven fabric and nanofibers is measured. 2 The weight of the nanofibers (g / m²) is obtained by subtracting the former from the latter. 2 Throughout the process, the spinning voltage, liquid supply speed, receiving distance, and nonwoven fabric winding speed remained consistent, and the nanofiber production was converted into g / m based on the nonwoven fabric winding speed. 2 The unit is / h.

[0041] Case 1: The needleless electrospinning device of this embodiment

[0042] Solution preparation: Dissolve 200g of polyurethane granules in 800g of N,N-dimethylacetamide and stir rapidly in a water bath at 60℃ for 6 hours. After stirring, cool and set aside.

[0043] Electrospinning: The needleless electrospinning device designed in this embodiment is used. The spinning voltage is 60KV, the distance between the substrate and the wire electrode 2 is 28cm, and the coating device 3 is used to coat the surface with liquid. The liquid supply speed of each electrode wire is 30ml / h, and the winding speed of the nonwoven fabric is 0.1m / min. After spinning is completed, the output and the number of defects are calculated.

[0044] Comparative Example 1: Needleless electrospinning device without electric field stabilization device 5

[0045] Solution preparation: Dissolve 200g of polyurethane granules in 800g of N,N-dimethylacetamide and stir rapidly in a water bath at 60℃ for 6 hours. After stirring, cool and set aside.

[0046] Electrospinning: A needleless electrospinning device without electric field stabilization device 5 was used. The spinning voltage was 60KV, the distance between the substrate and the wire electrode was 28cm, and the surface was coated with liquid using a scraping device. The liquid supply speed for each electrode wire was 30ml / h, and the winding speed of the nonwoven fabric was 0.1m / min. After spinning was completed, the output and the number of defects were calculated.

[0047] The experimental results are shown in Table 1.

[0048] Table 1: Performance of Samples Prepared by Different Spinning Devices

[0049] Case 1 Comparative Example 1 Production (g / m2 / h) 32 28 Defects (number) 10 320

[0050] Compared to traditional needleless electrospinning devices, the number of defects was significantly reduced after adding the electric field stabilization device 5. This is because the added electric field plays a certain role in controlling the spinning process, reducing excitation instability, and thus avoiding droplet splashing caused by spinning instability, which leads to a large number of defects on the fiber membrane surface. Furthermore, the fiber membrane yield also slightly increased after adding the electric field auxiliary device, as the increased electric field promotes the excitation of nanofibers, resulting in increased yield. The nanofibers prepared with the added electric field stabilization device 5 have better morphology, with fewer fiber strands and beads, further demonstrating that this device has a good control effect on the excitation instability of nanofibers on traditional wire electrodes.

Claims

1. A needleless electrospinning device, comprising: Frame (1); Line electrode (2) is mounted across the frame (1); The coating device (3) is slidably mounted on the online electrode (2) and connected to the liquid supply device; Its features are, Also includes The electric field stabilizing device (5) includes a metal ring (51) and a connector (52) that connects the metal ring (51) to the line electrode (2). The metal ring (51) is horizontally positioned below the line electrode (2).

2. The needleless electrospinning device according to claim 1, characterized in that, It includes multiple line electrodes (2) and metal rings (51) corresponding to the number of line electrodes (2), with a metal ring (51) disposed below each line electrode (2).

3. The needleless electrospinning apparatus according to claim 1 or 2, characterized in that, The metal ring (51) includes two straight first ring body portions (511) parallel to the line electrode (2), and a second ring body portion (512) extending from the end of the first ring body portions (511) and connecting the two parallel first ring body portions (511) into a ring.

4. The needleless electrospinning device according to claim 3, characterized in that, The two first annular portions (511) are located on both sides of their corresponding line electrodes (2) and are equidistant from the line electrodes (2).

5. The needleless electrospinning device according to claim 4, characterized in that, The connector (52) is integrally formed with the metal ring (51). The connector (52) extends vertically upward from the center of the second ring body (512) of the metal ring (51), and a connection hole (521) is provided at its end. The connector (52) is sleeved on the wire electrode (2) through the connection hole (521).

6. The needleless electrospinning apparatus according to claim 1, characterized in that, It also includes a limiting member (6), which has a limiting hole. The limiting member (6) is sleeved and fixed to the wire electrode (2) through the limiting hole and is closely disposed on the outside of the connector (52).

7. The needleless electrospinning apparatus according to claim 1, characterized in that, It also includes a high-voltage generating device for providing high-voltage current, wherein the electric field stabilizing device (5) and the line electrode (2) share the same high-voltage generating device.

8. The needleless electrospinning apparatus according to claim 1, characterized in that, The coating device (3) includes a sliding member (31) with a coating hole (311). The sliding member (31) is sleeved on the wire electrode (2) through the coating hole (311). The coating device (3) also includes a liquid delivery tube (32). One end of the liquid delivery tube (32) is connected to a liquid supply device, and the other end is connected to the coating hole (311) and delivers spinning solution to the coating hole (311).

9. The needleless electrospinning apparatus according to claim 1, characterized in that, It also includes a liquid collection tank (4), which is located at the bottom of the frame (1) and below the wire electrode (2).

10. The needleless electrospinning apparatus according to claim 1, characterized in that, The frame (1) includes a horizontal base plate and two opposing vertical side plates. The upper end of the side plates is provided with fixing holes (11). The two ends of the wire electrode (2) are respectively inserted into the fixing holes (11) of the two side plates and thus straddle the frame (1).

Images