A low-arc liquid surface multi-jet nozzle and spinning module for electrospinning

Abstract

This invention relates to a low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, comprising: a multi-jet single nozzle, a spinneret for microfiber, and thickness-compensating spinnerets on both sides; the multi-jet single nozzle has a dumbbell-shaped flow channel inside, with a cantilever rod at the upper end of the dumbbell-shaped flow channel, and an electric field strengthening and homogenizing module connected in the middle of the cantilever rod; the cross-section of the dumbbell-shaped flow channel is narrowed in the middle and has an inner insulating layer; the entire dumbbell-shaped flow channel is wrapped with an outer insulating tube; the solution flows inside the dumbbell-shaped flow channel; the dumbbell-shaped flow channel is connected to a high electrostatic voltage loading device; the microfiber spinneret reciprocates left and right, and both ends of the microfiber spinneret have insulating plates flush with the top of the microfiber spinneret; both the microfiber spinneret and the thickness-compensating spinnerets are equipped with nozzle insulating bases. Compared with the prior art, this invention achieves multi-jet from a single nozzle, achieves stable loading of high electrostatic voltage, achieves high-density spinning, and increases electrospinning output.

Description

Technical Field

[0001] This invention relates to the field of electrospinning apparatus, and in particular to a low-radius liquid surface multi-jet nozzle and spinning module for electrospinning. Background Technology

[0002] Electrospinning has become one of the main methods for producing microfibers due to its controllable process, simple equipment, and wide applicability. Under the influence of a high-voltage electrostatic field, the solution or melt becomes charged and deforms, forming a cone-shaped droplet at the nozzle. When the repulsive force of the charge on the droplet surface exceeds its surface tension, a tiny jet is ejected from the tip of the Taylor cone. Through high-speed stretching under the electric field, solvent evaporation, and solidification, microfibers are initially formed. Typically, each nozzle in the electrospinning process can only produce one jet, resulting in low microfiber yield and high production costs, failing to meet the requirements of industrialization.

[0003] To address the challenge of improving the efficiency of electrospinning production, existing technologies offer various solutions to achieve multi-jet output from a single nozzle. Patent ZL201811519081.0 discloses an electrospinning device and method with a built-in electrode in a vacuum environment. This device suspends the electrode inside the nozzle and evacuates the cavity containing the electrode. The electrode's function is solely to induce an electrical charge in the nozzle, causing the melt or solution on the outer surface of the spinning nozzle to become charged and form multiple jets. However, the annular flow channel used for melt flow and dispersion has a small gap and is prone to clogging, affecting production stability. Patent ZL201810417357.8 discloses a spherical electrospinning nozzle for controlling the electric field distribution under constant spinning solution curvature and its use. The nozzle includes a copper sphere with multiple grooves on its surface. Multiple polytetrafluoroethylene (PTFE) filler blocks are installed in the grooves. Under high static voltage, the spinning solution can generate a large jet at the copper sphere and PTFE filler blocks of the spherical electrospinning nozzle. However, the spinning direction of this electrospinning nozzle device is restricted, and the spinning solution is in large-area contact with air, making the solvent highly volatile, thus affecting the continuity of spinning. Patent ZL201310059377.X discloses a method and apparatus for improving multi-jet electrospinning. This apparatus has a metal needle positioned opposite the spinneret, on the same side as the receiving device. When the electric field strength reaches a certain value, multiple jets can be formed. Combined with multi-nozzle technology, this method can increase fiber production. However, the number of jets formed at a single nozzle is small, and the nozzle arrangement cannot improve the utilization rate of the fiber material. Patent ZL201320542047.1 discloses a hemispherical electrospinning spinneret. This spinneret has a nozzle tube and a nozzle. The upper part of the nozzle is fitted into the lower part of the nozzle tube, and the lower part of the nozzle is hemispherical with mesh openings. Multiple jets can be generated simultaneously on the nozzle surface. However, the uniformity of the electric field strength on the nozzle surface of this spinning spinneret is poor, resulting in unstable multi-jet formations and affecting production efficiency.

[0004] Therefore, there is an urgent need to develop a wide-inner-diameter, low-arc liquid surface multi-jet single nozzle and spinning module for electrospinning, which is expected to solve the above-mentioned bottleneck problems and is of great significance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology, such as the difficulty in increasing the number of jets from a single nozzle in electrospinning, poor stability of multiple jets, difficulty in improving spinning production efficiency, and low utilization of fiber materials, and to provide a low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, so as to realize multiple jets from a single nozzle, achieve stable loading of high static voltage, and improve electrospinning output.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] The present invention provides a low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, comprising: a multi-jet single nozzle, a spinneret for microfiber and thickness-compensating spinnerets on both sides.

[0008] The multi-jet single nozzle has a dumbbell-shaped flow channel inside. The upper end of the dumbbell-shaped flow channel is provided with a cantilever rod. An electric field strengthening uniform module is connected in the middle of the cantilever rod. The cross-section of the dumbbell-shaped flow channel is narrowed and an inner insulating layer is provided. The entire dumbbell-shaped flow channel is wrapped with an outer insulating tube. The solution flows inside the dumbbell-shaped flow channel. The dumbbell-shaped flow channel is connected to a high static voltage loading device.

[0009] The spinneret for microfiber reciprocates left and right. Both ends of the spinneret are equipped with insulating plates that are flush with the top of the spinneret. The spacing between the multi-jet single nozzles of the thickness-compensating spinneret is larger than that of the multi-jet single nozzles of the microfiber spinneret. Both the microfiber spinneret and the thickness-compensating spinneret are equipped with nozzle insulating bases.

[0010] This invention utilizes the capillary force generated by the dumbbell-shaped flow channel and the wide inner diameter nozzle to form a low-curvature liquid surface, achieving multiple jets from a single nozzle under static voltage. Simultaneously, the electric field superposition principle of the electric field uniformity module is used to increase the electric field strength and uniformity of the low-curvature liquid surface, further increasing the number of jets at the nozzle. The inner insulating layer in the middle of the dumbbell-shaped flow channel suppresses the generation of opposite charges, avoiding charge dissipation and achieving stable loading of high static voltage. By setting an insulating base and insulating plate for the nozzle, electric field interference between nozzles is reduced, achieving high-density nozzle arrangement. At the same time, a thickness-compensating spinneret is set to ensure the overall uniformity of the fiber material and improve material utilization. The aim is to increase spinning output while ensuring fiber material quality.

[0011] Furthermore, the installation direction of the thickness-compensating spinneret is consistent with the movement direction of the receiving substrate. The number of liquid-discharging nozzles on the thickness-compensating spinneret increases sequentially according to their distance from the microfiber spinneret, while the number of non-liquid-discharging nozzles on the thickness-compensating spinneret decreases sequentially according to their distance from the microfiber spinneret. This ensures the uniformity of the overall thickness of the fiber material.

[0012] Furthermore, the dumbbell-shaped flow channel has a structure that is wider at the top and bottom and narrower in the middle. The inner diameters at both ends of the dumbbell-shaped flow channel are the same and consistent with the inner diameter of the multi-jet single nozzle, both being 1-4 mm. The inner diameter of the middle part of the dumbbell-shaped flow channel is 0.1-0.9 mm. The upper end of the dumbbell-shaped flow channel is arc-shaped. The angle between the lower end of the dumbbell-shaped flow channel and the extension line of the middle part of the dumbbell-shaped flow channel ranges from 45-90°. The length of the multi-jet single nozzle is 20-50 mm.

[0013] Furthermore, the electric field strengthening uniform module includes conductive filaments of different shapes, including claw-shaped, needle-shaped, plate-shaped, column-shaped, and ring-shaped, with a length of 15-45 mm.

[0014] Furthermore, the dumbbell-shaped flow channel, cantilever rod, and electric field strengthening uniformity module are all made of materials including: copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, and stainless steel.

[0015] Furthermore, the materials of the inner insulating layer, outer insulating tube, nozzle insulating base, and insulating plates at both ends of the multi-jet single nozzle all include: polyurethane, polyester, polyimide, polyoxymethylene, polypropylene, polyethylene, polycarbonate, poly(p-phenylene terephthalamide), polyvinyl chloride, polyetheretherketone, and silicone rubber. The inner insulating layer can suppress the generation of opposite charges, avoid charge dissipation, and achieve stable loading of high static voltage. The outer insulating tube, single nozzle insulating base, and insulating plates at both ends of the nozzle can reduce electric field interference between single nozzles and between spinnerets, achieving low-interference high-density spinning.

[0016] Furthermore, the nozzle of the multi-jet single nozzle can form a low-arc liquid surface, the angle between the low-arc liquid surface and the nozzle is 10 to 30°, and multiple jets can be generated at the nozzle, with the number of jets being 2 to 30.

[0017] Furthermore, the length of the spinneret for the microfiber is 80-320cm, the width is 4-8cm, the height is 4-8cm, and the number is 4-16. The length of the thickness compensation spinneret is 20-120cm, the width is 8-24cm, the number is 4-6, and the height is 4-8cm.

[0018] Furthermore, the spinneret for microfiber has 40-80 nozzles, the nozzle spacing is 20-40mm, and the nozzles are arranged in one row; the thickness compensation spinneret has 20-40 nozzles, the nozzles are arranged in 2-4 rows, and the nozzle spacing is 40-60mm; the thickness compensation spinneret has 10-20 liquid-discharging nozzles and 10-20 non-liquid-discharging nozzles.

[0019] Furthermore, the applied voltage range of the high static voltage loading device is 0–150 kV.

[0020] The technical principle of this invention is as follows:

[0021] The dumbbell-shaped flow channel, wider at the top and bottom and narrower in the middle, allows the solution to form a low-curvature liquid surface at the nozzle. This is because when the solution comes into contact with the surface of the dumbbell-shaped flow channel, the solution rises along the flow channel surface due to surface tension. The structure, wider at the bottom and narrower at the top, enhances this capillary force, causing the solution to be attracted by stronger surface tension in the narrower middle section, thereby increasing the rising speed to form a low-curvature liquid surface and preventing the solution from dripping during spinning from top to bottom. Due to the low curvature of the liquid surface, the interaction between liquid molecules reduces the surface area of ​​the liquid surface, forming a smooth and slender liquid tip. Under the action of high electrostatic voltage, the liquid tip is stretched, eventually forming multiple jets at a single nozzle. Meanwhile, the inner insulating layer inside the nozzle can suppress the generation of opposite charges, thereby avoiding charge dissipation and achieving stable loading of high static voltage. Furthermore, by utilizing the electric field superposition principle of the electric field enhancement uniform module, the electric field strength and uniformity of the low-curvature liquid surface at the nozzle are increased, further improving the jet quantity of a single nozzle. The frictional force per unit volume between the solution and the inner wall of the dumbbell-shaped flow channel decreases with the increase of the nozzle diameter, thereby increasing the flow rate of the solution and increasing the output. Furthermore, the nozzle insulating base and insulating plate can effectively prevent current from passing through by utilizing the high resistivity, electronic structure, dielectric strength, and polarization characteristics of their materials, thereby reducing electric field interference between nozzles and spinnerets. At the same time, the thickness compensation spinneret is installed perpendicular to the direction of the microfiber spinneret and is located on both sides of it, which can compensate for the thickness of the fiber material edge. The number of liquid-discharging nozzles on the thickness compensation spinneret increases sequentially according to the distance from the microfiber spinneret, and the spacing between a single nozzle is greater than the spacing between a single nozzle on the microfiber spinneret, reducing electric field interference between nozzles, ensuring the uniformity of fiber material thickness, and improving the utilization rate of fiber material.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) A dumbbell-shaped conductive liquid outlet channel is set inside the single nozzle. The low arc liquid surface is formed by the capillary force and the wide inner diameter nozzle. Under the action of static voltage, multiple jets are realized from a single nozzle. At the same time, the inner insulating layer in the middle of the channel can suppress the generation of opposite charges, avoid charge dissipation, and realize the stable loading of high static voltage.

[0024] (2) The electric field uniformity module inside the single nozzle increases the electric field strength and uniformity of the low-curvature liquid surface, further increasing the number of jets at the nozzle and improving the electrospinning output.

[0025] (3) A single-nozzle insulating base is set on the spinneret to reduce electric field interference between the nozzles and achieve high-density arrangement of the nozzles; insulating plates are set at both ends of the spinneret for microfiber to reduce electric field interference with the thickness compensation spinneret and ensure normal spinning of each spinneret.

[0026] (4) A thickness compensation spinneret is installed in the spinning module. The number of liquid outlet nozzles of the thickness compensation spinneret increases in order of distance from the spinneret used for microfiber. The spacing between a single nozzle is greater than that between a single nozzle of the spinneret used for microfiber. This reduces electric field interference between nozzles, ensures that the thickness at both ends of the fiber material is consistent with the thickness in the middle, achieves uniformity of fiber material thickness, and improves the utilization rate of fiber material. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a low-arc liquid surface multi-jet single nozzle structure for electrospinning according to the present invention;

[0028] Figure 2 This is a schematic diagram of the high-density spinning module with low electric field interference of the present invention;

[0029] Figure 3 A bottom view of the thickness-compensated spinneret.

[0030] Reference numerals: 1-Dumbbell-shaped flow channel, 2-Cantilever rod, 3-Inner insulation layer, 4-Outer insulation tube, 5-Electric field strengthening uniform module, 6-High static voltage loading device, 7-Spinneret for microfiber, 8-Multi-jet single nozzle, 9-Nozzle insulation base, 10-Insulation plate, 11-Thickness compensation spinneret, 12-Liquid outlet nozzle, 13-Non-liquid outlet nozzle. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0032] A low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, such as Figure 1 , 2As shown in Figure 3, it includes: a multi-jet single nozzle 8, a microfiber spinneret 7, and thickness-compensating spinnerets 11 on both sides;

[0033] The multi-jet single nozzle 8 has a dumbbell-shaped flow channel 1 inside. The upper end of the dumbbell-shaped flow channel 1 is provided with a cantilever rod 2. An electric field strengthening uniform module 5 is connected in the middle of the cantilever rod 2. The cross-section of the dumbbell-shaped flow channel 1 is narrowed and an inner insulating layer 3 is provided. The entire dumbbell-shaped flow channel 1 is wrapped with an outer insulating tube 4. The solution flows inside the dumbbell-shaped flow channel 1. The dumbbell-shaped flow channel 1 is connected to a high static voltage loading device 6.

[0034] The microfiber spinneret 7 reciprocates left and right. Both ends of the microfiber spinneret 7 are provided with insulating plates 10 that are flush with the top of the microfiber spinneret 7. The spacing between the multi-jet single nozzles 8 of the thickness compensation spinneret 11 is greater than that of the multi-jet single nozzles 8 of the microfiber spinneret 7. Both the microfiber spinneret 7 and the thickness compensation spinneret 11 are provided with nozzle insulating bases 9.

[0035] This invention utilizes the capillary force generated by the dumbbell-shaped flow channel 1 and the wide inner diameter nozzle to form a low-curvature liquid surface, achieving multiple jets from a single nozzle under static voltage. Simultaneously, the electric field superposition principle of the electric field uniformity module is used to increase the electric field strength and uniformity of the low-curvature liquid surface, further increasing the number of jets at the nozzle. The inner insulating layer 3 in the middle of the dumbbell-shaped flow channel 1 suppresses the generation of opposite charges, avoiding charge dissipation and achieving stable loading of high static voltage. By setting the nozzle insulating base 9 and the insulating plate 10, electric field interference between nozzles is reduced, achieving high-density nozzle arrangement. At the same time, a thickness-compensating spinneret 11 is set to ensure the overall uniformity of the fiber material and improve material utilization. The aim is to increase spinning output while ensuring fiber material quality.

[0036] In a specific embodiment, the installation direction of the thickness-compensating spinneret 11 is consistent with the movement direction of the receiving substrate. The number of liquid-discharging nozzles 12 on the thickness-compensating spinneret 11 increases sequentially according to their distance from the microfiber spinneret 7, while the number of non-liquid-discharging nozzles 13 on the thickness-compensating spinneret 11 decreases sequentially according to their distance from the microfiber spinneret 7. This ensures the uniformity of the overall thickness of the fiber material.

[0037] In a specific embodiment, the dumbbell-shaped flow channel 1 has a structure that is wider at the top and bottom and narrower in the middle. The inner diameters at both ends of the dumbbell-shaped flow channel 1 are the same and consistent with the inner diameter of the multi-jet single nozzle 8, both being 1 to 4 mm. The inner diameter of the middle part of the dumbbell-shaped flow channel 1 is 0.1 to 0.9 mm. The upper end of the dumbbell-shaped flow channel 1 is arc-shaped. The angle between the lower end of the dumbbell-shaped flow channel 1 and the extension line of the middle part of the dumbbell-shaped flow channel 1 is in the range of 45 to 90°. The length of the multi-jet single nozzle 8 is 20 to 50 mm.

[0038] In a specific embodiment, the electric field strengthening uniformity module 5 includes conductive filaments of different shapes, including claw-shaped, needle-shaped, plate-shaped, column-shaped, and ring-shaped, with a length of 15 to 45 mm.

[0039] In a specific embodiment, the dumbbell-shaped flow channel 1, the cantilever rod 2, and the electric field strengthening uniform module 5 are all made of the following materials: copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, and stainless steel.

[0040] In a specific embodiment, the materials of the inner insulating layer 3, the outer insulating tube 4, the nozzle insulating base 9, and the insulating plates 10 at both ends of the multi-jet single nozzle 8 all include: polyurethane, polyester, polyimide, polyoxymethylene, polypropylene, polyethylene, polycarbonate, poly(p-phenylene terephthalamide), polyvinyl chloride, polyetheretherketone, and silicone rubber. The inner insulating layer 3 can suppress the generation of opposite charges, avoid charge dissipation, and achieve stable loading of high static voltage. The outer insulating tube 4, the single nozzle insulating base 9, and the insulating plates 10 at both ends of the nozzle can reduce electric field interference between single nozzles and between spinnerets, achieving low-interference high-density spinning.

[0041] In a specific embodiment, the nozzle of the multi-jet single nozzle 8 can form a low-arc liquid surface, the angle between the low-arc liquid surface and the nozzle is 10 to 30°, and multiple jets can be generated at the nozzle, with the number of jets being 2 to 30.

[0042] In a specific embodiment, the length of the microfiber spinneret 7 is 80-320cm, the width is 4-8cm, the height is 4-8cm, and the number is 4-16. The length of the thickness compensation spinneret 11 is 20-120cm, the width is 8-24cm, the number is 4-6, and the height is 4-8cm.

[0043] In a specific embodiment, the number of nozzles on the microfiber spinneret 7 is 40-80, the nozzle spacing on the microfiber spinneret 7 is 20-40mm, and the number of nozzle rows on the microfiber spinneret 7 is 1; the number of nozzles on the thickness compensation spinneret 11 is 20-40, the number of nozzle rows on the spinneret is 2-4, and the nozzle spacing on the thickness compensation spinneret 11 is 40-60mm; the number of liquid-discharging nozzles 12 on the thickness compensation spinneret 11 is 10-20, and the number of non-discharging nozzles 13 on the thickness compensation spinneret 11 is 10-20.

[0044] In a specific embodiment, the applied voltage range of the high static voltage loading device 6 is 0 to 150 kV.

[0045] Example 1

[0046] The ultrafine fiber material was prepared using the aforementioned low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, following the steps below:

[0047] Step 1: Select a dumbbell-shaped flow channel 1 with an inner diameter of 1.2mm at the top and bottom, an inner diameter of 0.4mm in the middle, an arc shape at the top, and an angle of 45° between the extension line of the lower flow channel and the middle flow channel. The multi-jet single nozzle 8 has an inner diameter of 1.2mm and a length of 25mm. The dumbbell-shaped flow channel 1, the cantilever rod 2, and the electric field strengthening uniformity module 5 are made of aluminum. The electric field uniformity strengthening module 5 is annular in shape and has a length of 20mm. The inner insulation layer 3 and the outer insulation tube 4 are made of polyoxymethylene.

[0048] Step 2: The prepared mullite sol is poured into the dumbbell-shaped flow channel 1. The high static voltage loading device 6 applies a voltage of 60kV. Under the continuous action of the electric field, the angle between the low-curvature liquid surface and the nozzle is 12°. 25 jets can be formed at a single nozzle, realizing multiple jets from a single nozzle. Subsequently, the solvent evaporates, and the multiple jets are stretched and refined into ultrafine fibers.

[0049] Step 3: The multi-jet single-nozzle units 8 are arranged and combined to form a low-interference, high-density spinning module. The spinneret 7 for microfiber has a length of 170cm, a width of 4cm, a height of 4cm, and a quantity of 8 units. The spinneret 7 has 68 nozzles with a nozzle spacing of 25mm. The thickness-compensating spinneret 11 has a length of 50cm, a width of 20cm, a height of 4cm, and a quantity of 6 units. The thickness-compensating spinneret 11 has 40 nozzles arranged in 4 columns, with 10 nozzles per column and a nozzle spacing of 50mm. The thickness-compensating spinneret 11 has 18 liquid-discharging nozzles 12 and 12 non-liquid-discharging nozzles 13. Ultimately, the jet density of the microfiber spinneret 7 is 1000 fibers / m, and the jet density of the thickness-compensating spinneret 11 is 900 fibers / m.

[0050] Example 2

[0051] The ultrafine fiber material was prepared using the aforementioned low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, following the steps below:

[0052] Step 1: Select a dumbbell-shaped flow channel 1 with an inner diameter of 1mm at the top and bottom, an inner diameter of 0.6mm in the middle, an arc shape at the top, and an angle of 45° between the extension line of the lower flow channel and the middle flow channel. The multi-jet single nozzle 8 has an inner diameter of 1mm and a length of 20mm. The dumbbell-shaped flow channel 1, the cantilever rod 2, and the electric field strengthening uniformity module 5 are made of stainless steel. The electric field strengthening uniformity module 5 is plate-shaped with a length of 15mm. The inner insulation layer 3 and the outer insulation tube 4 are made of polypropylene.

[0053] Step 2: The prepared polytetrafluoroethylene solution is poured into the dumbbell-shaped flow channel 1. The high static voltage loading device 6 applies a voltage of 50kV. Under the continuous action of the electric field force, the angle between the low-curvature liquid surface and the nozzle is 15°. 20 jets can be formed at a single nozzle, realizing multiple jets from a single nozzle. Subsequently, the solvent evaporates, and the multiple jets are stretched and refined into ultrafine fibers.

[0054] Step 3: The multi-jet single-nozzle units 8 are arranged and combined to form a low-interference, high-density spinning module. The spinneret 7 for microfiber has a length of 168cm, a width of 5cm, a height of 5cm, and a quantity of 12 units. The spinneret 7 has 60 nozzles with a nozzle spacing of 28mm. The thickness-compensating spinneret 11 has a length of 20cm, a width of 8cm, a height of 5cm, and a quantity of 4 units. The thickness-compensating spinneret 11 has 20 nozzles arranged in 2 columns, with 5 nozzles per column and a nozzle spacing of 40mm. The thickness-compensating spinneret 11 has 10 liquid-discharging nozzles 12 and 10 non-liquid-discharging nozzles 13. Ultimately, the jet density of the microfiber spinneret 7 is 714 nozzles / m, and the jet density of the thickness-compensating spinneret 11 is 1000 nozzles / m.

[0055] Example 3

[0056] The ultrafine fiber material was prepared using the aforementioned low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, following the steps below:

[0057] Step 1: Select a dumbbell-shaped flow channel 1 with an inner diameter of 4mm at the top and bottom, an inner diameter of 0.1mm in the middle, an arc shape at the top, and an angle of 60° between the extension line of the lower flow channel and the middle flow channel. The multi-jet single nozzle 8 has an inner diameter of 4mm and a length of 40mm. The dumbbell-shaped flow channel 1, the cantilever rod 2, and the electric field strengthening uniformity module 5 are made of copper. The electric field strengthening uniformity module 5 is needle-shaped with a length of 35mm. The inner insulating layer 3 and the outer insulating tube 4 are made of poly(p-phenylene terephthalamide).

[0058] Step 2: The prepared zirconium sol is poured into the dumbbell-shaped flow channel 1. The high static voltage loading device 6 applies a voltage of 150kV. Under the continuous action of the electric field, the angle between the low-curvature liquid surface and the nozzle is 10°. 30 jets can be formed at a single nozzle, realizing multiple jets from a single nozzle. Subsequently, the solvent evaporates, and the multiple jets are stretched and refined into ultrafine fibers.

[0059] Step 3: The multi-jet single-nozzle units 8 are arranged and combined to form a low-interference, high-density spinning module. The spinneret 7 for microfiber is 320cm long, 8cm wide, and 8cm high, with 16 units. The spinneret 7 has 80 nozzles with a spacing of 40mm. The thickness-compensating spinneret 11 is 120cm long, 12cm wide, and 8cm high, with 6 units. The thickness-compensating spinneret 11 has 40 nozzles arranged in two columns, each with 20 nozzles and a spacing of 60mm. The thickness-compensating spinneret 11 has 20 liquid-discharging nozzles 12 and 20 non-liquid-discharging nozzles 13. Ultimately, the jet density of the microfiber spinneret 7 is 750 spinnerets / m, and the jet density of the thickness-compensating spinneret 11 is 500 spinnerets / m.

[0060] Example 4

[0061] The ultrafine fiber material was prepared using the aforementioned low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, following the steps below:

[0062] Step 1: Select a dumbbell-shaped flow channel 1 with an inner diameter of 1mm at the top and bottom, an inner diameter of 0.9mm in the middle, an arc shape at the top, and an angle of 45° between the extension line of the lower flow channel and the middle flow channel. The multi-jet single nozzle 8 has an inner diameter of 1mm and a length of 45mm. The dumbbell-shaped flow channel 1, the cantilever rod 2, and the electric field strengthening uniformity module 5 are made of copper alloy. The electric field strengthening uniformity module 5 is claw-shaped and has a length of 40mm. The inner insulation layer 3 and the outer insulation tube 4 are made of polyetheretherketone.

[0063] Step 2: The prepared polyvinyl alcohol is injected into the dumbbell-shaped flow channel 1. The high static voltage loading device 6 applies a voltage of 30kV. Under the continuous action of the electric field, the angle between the low-curvature liquid surface and the nozzle is 18°. 18 jets can be formed at a single nozzle, realizing multiple jets from a single nozzle. Subsequently, the solvent evaporates, and the multiple jets are stretched and refined into ultrafine fibers.

[0064] Step 3: The multi-jet single-nozzle units 8 are arranged and combined to form a low-interference, high-density spinning module. The microfiber spinneret 7 has a length of 80cm, a width of 6cm, a height of 6cm, and a quantity of 4 units. The microfiber spinneret 7 has 40 nozzles with a nozzle spacing of 20mm. The thickness-compensating spinneret 11 has a length of 40cm, a width of 8cm, and a height of 6cm, and a quantity of 6 units. The thickness-compensating spinneret 11 has 20 nozzles arranged in 2 columns, with 10 nozzles per column and a nozzle spacing of 40mm. The thickness-compensating spinneret 11 has 10 liquid-discharging nozzles 12 and 10 non-liquid-discharging nozzles 13. Ultimately, the jet density of the microfiber spinneret 7 is 900 spinnerets / m, and the jet density of the thickness-compensating spinneret 11 is 450 spinnerets / m.

[0065] Example 5

[0066] The ultrafine fiber material was prepared using the aforementioned low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, following the steps below:

[0067] Step 1: Select a dumbbell-shaped flow channel 1 with an inner diameter of 1.8mm at the top and bottom, an inner diameter of 0.6mm in the middle, an arc shape at the top, and an angle of 75° between the extension line of the lower flow channel and the middle flow channel. The multi-jet single nozzle 8 has an inner diameter of 1.8mm and a length of 50mm. The dumbbell-shaped flow channel 1, the cantilever rod 2, and the electric field strengthening uniformity module 5 are made of aluminum. The electric field strengthening uniformity module 5 is cylindrical in shape and has a length of 45mm. The inner insulation layer 3 and the outer insulation tube 4 are made of polycarbonate.

[0068] Step 2: The prepared silica sol is poured into the dumbbell-shaped flow channel 1. The high static voltage loading device 6 applies a voltage of 20kV. Under the continuous action of the electric field, the angle between the low-curvature liquid surface and the nozzle is 22°. 15 jets can be formed at a single nozzle, realizing multiple jets from a single nozzle. Subsequently, the solvent evaporates, and the multiple jets are stretched and refined into ultrafine fibers.

[0069] Step 3: The multi-jet single-nozzle units 8 are arranged and combined to form a low-interference, high-density spinning module. The spinneret 7 for microfiber is 150cm long, 5cm wide, and 5cm high, with 12 units. The spinneret 7 has 60 nozzles with a spacing of 25mm. The thickness-compensating spinneret 11 is 54cm long, 24cm wide, and 5cm high, with 6 units. The thickness-compensating spinneret 11 has 36 nozzles arranged in 4 columns, with 9 nozzles per column and a spacing of 60mm. The thickness-compensating spinneret 11 has 20 liquid-discharging nozzles 12 and 16 non-liquid-discharging nozzles 13. Ultimately, the jet density of the microfiber spinneret 7 is 600 spinnerets / m, and the jet density of the thickness-compensating spinneret 11 is 555 spinnerets / m.

[0070] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0071] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A low-arc liquid surface multi-jet nozzle and spinning module for electrospinning, characterized in that, include: Multi-jet single nozzle (8), microfiber spinneret (7) and thickness-compensating spinnerets (11) on both sides; The multi-jet single nozzle (8) is provided with a dumbbell-shaped flow channel (1) inside. The upper end of the dumbbell-shaped flow channel (1) is provided with a cantilever rod (2). An electric field strengthening uniform module (5) is connected in the middle of the cantilever rod (2). The cross section of the dumbbell-shaped flow channel (1) is narrowed and an inner insulating layer (3) is provided. The entire dumbbell-shaped flow channel (1) is wrapped with an outer insulating tube (4). The solution flows inside the dumbbell-shaped flow channel (1). The dumbbell-shaped flow channel (1) is connected to a high static voltage loading device (6). The microfiber spinneret (7) moves back and forth. The two ends of the microfiber spinneret (7) are provided with insulating plates (10) that are flush with the top of the microfiber spinneret (7). The spacing between the multi-jet single nozzles (8) of the thickness compensation spinneret (11) is greater than that of the multi-jet single nozzles (8) of the microfiber spinneret (7). Both the microfiber spinneret (7) and the thickness compensation spinneret (11) are provided with nozzle insulating bases (9).

2. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The installation direction of the thickness compensation spinneret (11) is consistent with the movement direction of the receiving substrate. The number of liquid outlet nozzles (12) on the thickness compensation spinneret (11) increases sequentially according to their distance from the microfiber spinneret (7), and the number of non-liquid outlet nozzles (13) on the thickness compensation spinneret (11) decreases sequentially according to their distance from the microfiber spinneret (7).

3. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The dumbbell-shaped flow channel (1) has a structure that is wide at the top and bottom and narrow in the middle. The inner diameters at both ends of the dumbbell-shaped flow channel (1) are the same and consistent with the inner diameter of the multi-jet single nozzle (8), which is 1 to 4 mm. The inner diameter of the middle part of the dumbbell-shaped flow channel (1) is 0.1 to 0.9 mm. The upper end of the dumbbell-shaped flow channel (1) is arc-shaped. The angle between the lower end of the dumbbell-shaped flow channel (1) and the extension line of the middle part of the dumbbell-shaped flow channel (1) is 45 to 90°. The length of the multi-jet single nozzle (8) is 20 to 50 mm.

4. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The electric field strengthening uniform module (5) includes conductive filaments of different shapes, including claw-shaped, needle-shaped, plate-shaped, column-shaped, and ring-shaped, with a length of 15 to 45 mm.

5. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The dumbbell-shaped flow channel (1), cantilever rod (2) and electric field strengthening uniform module (5) are all made of the following materials: copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, and stainless steel.

6. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The materials of the inner insulation layer (3), outer insulation tube (4), nozzle insulation base (9), and insulation plates (10) at both ends of the multi-jet single nozzle (8) all include: polyurethane, polyester, polyimide, polyoxymethylene, polypropylene, polyethylene, polycarbonate, poly(p-phenylene terephthalamide), polyvinyl chloride, polyether ether ketone, and silicone rubber. The inner insulation layer (3) can suppress the generation of opposite charges, avoid charge dissipation, and achieve stable loading of high static voltage. The outer insulation tube (4), single nozzle insulation base (9), and insulation plates (10) at both ends of the nozzle can reduce electric field interference between single nozzles and between spinnerets, and achieve low-interference high-density spinning.

7. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The multi-jet single nozzle (8) can form a low-arc liquid surface at the nozzle, with an angle of 10 to 30° between the low-arc liquid surface and the nozzle, and can generate multiple jets at the nozzle, with the number of jets being 2 to 30.

8. The low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The length of the microfiber spinneret (7) is 80-320cm, the width is 4-8cm, the height is 4-8cm, and the number is 4-16. The length of the thickness compensation spinneret (11) is 20-120cm, the width is 8-24cm, the number is 4-6, and the height is 4-8cm.

9. A low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 2, characterized in that, The number of nozzles on the microfiber spinneret (7) is 40 to 80, the nozzle spacing on the microfiber spinneret (7) is 20 to 40 mm, and the number of nozzles arranged in one row on the microfiber spinneret (7); the number of nozzles on the thickness compensation spinneret (11) is 20 to 40, the number of nozzles arranged in two to four rows on the spinneret, the nozzle spacing on the thickness compensation spinneret (11) is 40 to 60 mm, the number of liquid-discharging nozzles (12) on the thickness compensation spinneret (11) is 10 to 20, and the number of non-liquid-discharging nozzles (13) on the thickness compensation spinneret (11) is 10 to 20.

10. A low-arc liquid surface multi-jet nozzle and spinning module for electrospinning according to claim 1, characterized in that, The high static voltage loading device (6) applies a voltage range of 0 to 150 kV.

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