Supercritical electrostatic spraying continuous spinning system and method

Abstract

The invention discloses a supercritical electrostatic spraying continuous spinning system and method, and belongs to the technical field of fiber preparation. The supercritical electrostatic spraying continuous spinning system comprises a screw extruder, a dynamic mixing device, a homogenization reaction device, a spinning device, a supercritical fluid supply device, a material conveying device and a solvent supply device, and can realize continuous feeding, continuous dissolving and spinning of a polymer at high temperature and high pressure; according to the invention, efficient and rapid dissolution of a polymer can be realized through the screw extruder; the product prepared by the method has excellent mechanical properties and excellent fiber uniformity, and can be widely applied to the fields of medical packaging, individual protection, industrial packaging, building maintenance, transportation, agriculture, military and the like.

Description

Technical Field

[0001] This invention relates to the field of fiber preparation technology, specifically to a supercritical electrostatic jet spinning system and method. Background Technology

[0002] Supercritical electrostatic jet technology (SEJ) is a highly efficient technology for producing ultrafine fibers. Its core lies in achieving instantaneous phase separation of the polymer solution through the rapid evaporation of the solvent under high temperature and pressure. This instantaneous separation of the solvent, carrying a specific electrical charge, endows the micro / nanofibers with controllable electrical properties. After leaving the nozzle, the micro / nanofibers form a continuous three-dimensional network structure. Nonwoven fabrics made from this network structure possess excellent mechanical properties, superior barrier properties, and breathability, and are widely used in medical packaging, personal protective equipment, industrial packaging, building maintenance, transportation, agriculture, and military fields. As a top-tier process for nonwoven material production, supercritical electrostatic jet technology has unique advantages and considerable technical difficulty compared to processes such as spunbond, meltblown, and electrospinning. The continuous dissolution process is the core link in the industrial production of fibers using SEJ, directly affecting fiber uniformity, production efficiency, and cost. At present, continuous dissolution processes need to solve three core problems: (1) Homogeneous dissolution of polymers: to achieve rapid mixing and stable homogenization of polymers (such as polyethylene and polypropylene) and solvents under high temperature and high pressure; (2) Solvent recycling efficiency: to recover and reuse solvents to reduce energy consumption and environmental pressure; (3) Process continuity control: to avoid fiber diameter dispersion or fiber breakage.

[0003] As a pioneer in microfiber spinning technology, DuPont has accumulated significant patent barriers in the field of continuous dissolution processes. US Patent No. 3461193A first disclosed a novel method for the rapid extrusion of expandable resin compositions. This method uses gas pressure to transport the polymer solution, but suffers from uncontrollable resin dissolution and insufficient efficiency. US Patent No. 3227794 discloses a continuous solution formation process that uses alkanes as a co-solvent to reduce the dissolution pressure of high-density polyethylene in traditional solvents (such as fluorohalogenated hydrocarbons) (from 30 MPa to 15–20 MPa). Continuously dissolved polymer is obtained through flash evaporation and spun into bundled fibers and network structures. While these existing technologies can reduce the dissolution pressure of polyethylene in traditional solvents to 15–20 MPa, achieving dissolution transport equipment and mass production under these pressure conditions remains extremely difficult. The equipment requires high standards for use and maintenance, has a narrow range of compatible equipment, and carries certain risks associated with high-pressure devices, making industrialization challenging. US Patent No. 5840234 discloses a multi-stage extruder and mixing system that achieves continuous homogenization of polymer solutions through segmented temperature control and shear force optimization. It also assists in the design of different screw combinations and static mixers to adjust mixing parameters and ensure dissolution stability. However, the use of a static mixer results in a relatively large pressure drop in the system, necessitating the application of relatively high pressures (20–30 MPa) during dissolution. Therefore, this technology still has certain limitations in industrial application.

[0004] Therefore, there is an urgent need to develop a supercritical electrostatic jet spinning system and method with higher safety and relatively low industrialization cost. Summary of the Invention

[0005] Based on the deficiencies of existing technologies, the purpose of this invention is to provide a supercritical electrostatic jet spinning system and method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a supercritical electrostatic jet continuous spinning system, comprising a screw extruder, a dynamic mixing device, a homogenization reaction device, a spinning device, a supercritical fluid supply device, a material conveying device, and a solvent supply device, wherein the discharge end of the screw extruder is connected to the inlet of the dynamic mixing device, the discharge outlet of the dynamic mixing device is connected to the inlet of the homogenization reaction device, and the discharge outlet of the homogenization reaction device is connected to the spinning device; The material conveying device is used to convey material, including polymer, to the screw extruder; The solvent supply device is connected to the screw extruder to supply organic solvent to the screw extruder; The solvent supply device is connected to the dynamic mixing device to supply organic solvent to the dynamic mixing device; The supercritical fluid supply device is connected to the dynamic mixing device to supply supercritical fluid to the dynamic mixing device.

[0007] Preferably, a filter is installed on the pipe between the outlet of the dynamic mixing device and the inlet of the homogenization reaction device; a filter is installed on the pipe between the outlet of the homogenization reaction device and the spinning device.

[0008] Preferably, the screw extruder includes a first solvent inlet and a second solvent inlet, and the solvent supply device is connected to the first solvent inlet and the second solvent inlet of the screw extruder respectively through pipes to supply organic solvent to the screw extruder through the first solvent inlet and the second solvent inlet.

[0009] More preferably, the screw extruder includes a barrel, a screw drive motor, and a screw. The screw is disposed inside the barrel, and one end of the screw is connected to the screw drive motor. The barrel is provided with N processing areas in sequence along the forward direction of the screw, which are the first area to the Nth area, where N is a positive integer from 16 to 20. The barrel has a material inlet, which is located in the first section of the barrel, and the material conveying device is connected to the material inlet of the barrel. The first solvent inlet is located in any one of the fourth to sixth zones of the barrel, and the second solvent inlet is located in any one of the eighth to ninth zones of the barrel; the solvent supply device is connected to the first solvent inlet of the barrel via a pipe and a metering pump, and the solvent supply device is connected to the second solvent inlet of the barrel via a pipe and a metering pump.

[0010] Preferably, the dynamic mixing device has a solvent inlet, and the solvent supply device is connected to the solvent inlet of the dynamic mixing device through a pipeline and a metering pump to continuously deliver organic solvent to the dynamic mixing device through the solvent inlet of the dynamic mixing device.

[0011] Secondly, the present invention provides a supercritical electrostatic jetting continuous spinning method, comprising the following steps: S1. Prepare materials, including polymers; S2. The material, the first organic solvent, and the second organic solvent are continuously fed into the screw extruder for melt mixing to obtain polymer solution A; S3. The polymer solution A obtained in step S2, the third organic solvent, and the co-solvent are continuously fed into the dynamic mixing device for stirring and mixing to obtain polymer solution B; the co-solvent is a supercritical fluid. S4. The polymer solution B obtained in step S3 is continuously fed into the homogenization reaction device for homogenization treatment to obtain the spinning solution. S5. The spinning solution obtained in step S4 is transported to the spinning device for spinning to obtain the initial sheet. S6. Heat and bond the initial sheet to obtain the sheet product; The total input flow rate is the sum of the input flow rates of the material, the first organic solvent, the second organic solvent, the third organic solvent, and the co-solvent, and the percentage of the input flow rate of the material in the total input flow rate is no more than 20 wt%.

[0012] Preferably, the total input flow rate is the sum of the input flow rates of the material, the first organic solvent, the second organic solvent, the third organic solvent, and the co-solvent. The input flow rate of the first organic solvent accounts for 10-35 wt% of the total input flow rate, the input flow rate of the second organic solvent accounts for 10-35 wt% of the total input flow rate, the input flow rate of the third organic solvent accounts for 10-60 wt% of the total input flow rate, the input flow rate of the co-solvent accounts for 5-20 wt% of the total input flow rate, and the input flow rate of the material accounts for 5-20 wt% of the total input flow rate. The first organic solvent, the second organic solvent, and the third organic solvent are preferably the same organic solvent.

[0013] Preferably, the material further includes an electrostatic enhancer, wherein the mass ratio of the electrostatic enhancer to the polymer is (1-40):100.

[0014] Preferably, the material further includes other additives, wherein the mass ratio of the other additives to the polymer is (0.5-10):100; the other additives may include antioxidants.

[0015] Preferably, the barrel of the screw extruder has a material inlet, a first solvent inlet, and a second solvent inlet. The barrel is provided with N processing zones in sequence along the forward direction of the screw of the screw extruder, which are zone 1 to zone N, where N is a positive integer from 16 to 20. The material inlet is located in zone 1 of the barrel, the first solvent inlet is located in any zone 4 to zone 6 of the barrel, and the second solvent inlet is located in any zone 8 to zone 9 of the barrel. In step S2, the first organic solvent enters the screw extruder through the first solvent inlet, and the second organic solvent enters the screw extruder through the second solvent inlet.

[0016] Preferably, in step S2, the conditions for melt mixing are: the screw extruder speed is 200-500 r / min, the screw extruder temperature is 120-240℃, and the screw extruder pressure is 10-15 MPa.

[0017] Preferably, in step S3, the stirring and mixing conditions are: a rotation speed of 100-200 rpm, a temperature of 200-220°C, and a residence time of 20-40 min.

[0018] Preferably, in step S4, the conditions for the homogenization reaction are: rotation speed of 150-300 rpm, temperature of 200-220°C, and residence time of 0.5-2 h.

[0019] Preferably, in step S5, the spinning conditions are: spinning pressure of 5-15 MPa, spinning temperature of 200-220°C, spinning voltage of 10-100 kV, transmission speed of the conductive collection device of 0.5-5 m / min, and receiving distance of 10-120 cm.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The supercritical electrostatic jet continuous spinning system of the present invention is equipped with a screw extruder, a dynamic mixing device, a homogenization reaction device and a spinning device connected in sequence through pipes, and is also equipped with a supercritical fluid supply device, which can realize continuous feeding, continuous dissolution and spinning of polymer under high temperature and high pressure. This invention enables efficient and rapid dissolution of polymers using a screw extruder; The products prepared by the method described in this invention have excellent mechanical properties and superior fiber uniformity, and can be widely used in medical packaging, personal protective equipment, industrial packaging, building maintenance, transportation, agriculture and military fields. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the supercritical electrostatic jet continuous spinning system provided by the present invention; Figure 2 This is a schematic diagram showing the distribution of meshing blocks on the screw located in zones one through three; Figure 3 This is a schematic diagram showing the distribution of the toothed disks on the screw located in zones four through nine; Figure 4 This is a schematic diagram showing the alternating distribution of meshing block groups and toothed disk groups on the screw located in zones 10 to N. Figure 5 A cross-sectional view of the screw extruder provided by the present invention; Figure 6 A cross-sectional view of the dynamic mixing device provided by the present invention; Figure 7 This is a schematic diagram of the homogenization reaction apparatus provided by the present invention.

[0022] In the diagram, 1-screw extruder, 11-barrel, 111-material inlet, 112-first solvent inlet, 113-second solvent inlet, 12-screw drive motor, 13-screw, 14-first meshing block, 15-first toothed disc, 16-second meshing block, 17-second toothed disc, 2-dynamic mixing device, 21-casing, 22-rotating motor, 23-shaft, 24-guide plate, 25-first agitator assembly, 251-first agitator, 252-first baffle, 2 6-Second stirring paddle assembly, 261-Second stirring paddle, 262-Second baffle plate, 27-First jacket, 3-Homogenization reaction device, 31-Reaction vessel body, 32-Stirring motor, 33-Stirring shaft, 34-Stirring blade, 35-Second jacket, 4-Spinning device, 5-Supercritical fluid supply device, 6-Metering pump, 7-Filter, 8-Material conveying device, 81-Material tank, 82-Screw conveyor, 9-Solvent supply device, 91-Solvent tank, 92-Solvent recovery device. Detailed Implementation

[0023] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below in conjunction with specific embodiments. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.

[0024] In the description of the embodiments herein, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 the embodiments herein and for simplifying the description, and are not intended to 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 limitations on the embodiments herein.

[0025] In the description of the embodiments herein, unless otherwise explicitly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments herein according to the specific circumstances.

[0026] In the description of the embodiments herein, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments herein, "multiple" means two or more, unless otherwise explicitly defined.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this applies; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this document; the terms “comprising” and “having”, and any variations thereof, in the description, claims, and accompanying drawings herein are intended to cover non-exclusive inclusion.

[0028] In this document, the term "implementation" means that a particular feature, structure, or characteristic described in connection with an implementation can be included in at least one implementation described herein. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations. It will be explicitly and implicitly understood by those skilled in the art that the implementations described herein can be combined with other implementations.

[0029] In the description of the embodiments herein, "several groups" refers to two or more groups (including two groups), and "several individuals" refers to two or more individuals (including two individuals).

[0030] Please see Figures 1-7 In a first aspect, the present invention provides a supercritical electrostatic jet continuous spinning system, comprising a screw extruder 1, a dynamic mixing device 2, a homogenization reaction device 3, a spinning device 4, a supercritical fluid supply device 5, a material conveying device 8, and a solvent supply device 9, wherein the output end of the screw extruder 1 is connected to the inlet of the dynamic mixing device 2 via a pipe and a metering pump 6, the outlet of the dynamic mixing device 2 is connected to the inlet of the homogenization reaction device 3 via a pipe and a metering pump 6, and the outlet of the homogenization reaction device 3 is connected to the spinning chamber of the spinning device 4 via a pipe. Material conveying device 8 is used to convey material, including polymer, to screw extruder 1; Solvent supply device 9 is connected to screw extruder 1 to supply organic solvent to screw extruder 1; Solvent supply device 9 is connected to dynamic mixing device 2 to supply organic solvent to dynamic mixing device 2; The output end of the supercritical fluid supply device 5 is connected to the dynamic mixing device 2 to supply supercritical fluid to the dynamic mixing device 2.

[0031] In some embodiments, a filter 7 is provided on the pipe between the outlet of the dynamic mixing device 2 and the inlet of the homogenization reaction device 3.

[0032] In some embodiments, a filter 7 is provided on the pipe between the outlet of the homogenization reaction device 3 and the spinning device 4.

[0033] In some embodiments, the screw extruder 1 includes a barrel 11, a screw drive motor 12, and a screw 13. The screw 13 is disposed inside the barrel 11, and one end of the screw 13 is connected to the screw drive motor 12. The barrel 11 has a material inlet 111, a first solvent inlet 112, and a second solvent inlet 113. A material conveying device 8 is connected to the material inlet 111 of the barrel 11. A solvent supply device 9 is connected to the first solvent inlet 112 of the barrel 11 through a pipe and a metering pump. The solvent supply device 9 is connected to the second solvent inlet 113 of the barrel 11 through a pipe and a metering pump. The barrel 11 has N processing zones arranged sequentially along the forward direction of the screw 13, which are the first zone to the Nth zone, where N is a positive integer from 16 to 20.

[0034] In some embodiments, the material inlet 111 is located in the first zone of the barrel 11, the first solvent inlet 112 is located in any of the fourth to sixth zones of the barrel 11, and the second solvent inlet 113 is located in any of the eighth to ninth zones of the barrel 11.

[0035] In some implementations, the lengths of the N processing zones are the same.

[0036] In some embodiments, the screw 13 located in the first to third zones is provided with a plurality of first engagement blocks 14 arranged sequentially along the axial direction of the screw 13, and the torsion angle between any two adjacent first engagement blocks 14 is 30 to 60°.

[0037] The screw 13 located in the fourth to ninth zones is provided with a number of first toothed discs 15 that are equally spaced along the axial direction of the screw 13.

[0038] The screw 13 located in the tenth to the Nth zone is provided with several sets of meshing blocks and several sets of toothed discs. The meshing block sets and the toothed disc sets are alternately distributed along the axial direction of the screw 13. Each set of meshing blocks has at least three second meshing blocks 16 arranged sequentially along the axial direction of the screw 13. The torsion angle between any two adjacent second meshing blocks 16 in each set of meshing blocks is 30 to 60°. Each set of toothed discs has at least three second toothed discs 17 arranged at equal intervals along the axial direction of the screw 13.

[0039] The inventors discovered through research that in the prior art, only a single meshing block or a single toothed disc is set on the screw. In contrast, the distribution of the meshing block and toothed disc in this invention can increase the blending effect of the resin and solvent.

[0040] In some embodiments, the processing area is equipped with a heating device for regulating the temperature of the processing area. The heating device includes an electric heater disposed within the wall of the barrel 11, a temperature sensor disposed within the barrel, and a temperature controller disposed outside the barrel 11. The temperature controller is electrically connected to the electric heater and the temperature sensor, respectively. The electric heater can be a resistance wire or an electric heating rod. By equipping each processing area with a heating device, this invention enables independent temperature control in different areas of the barrel.

[0041] In some embodiments, the length-to-diameter ratio of the screw extruder 1 is (32-86):1.

[0042] In this invention, the length-to-diameter ratio of the screw extruder 1 refers to the ratio of the effective length of the working part of the screw inside the screw extruder to the outer diameter of the screw.

[0043] In some embodiments, the material conveying device 8 includes a material tank 81 and a screw conveyor 82. The material outlet of the material tank 81 is connected to the feed inlet of the screw conveyor 82, and the discharge outlet of the screw conveyor 82 is connected to the material inlet 111 of the barrel 11 through a conveying pipe.

[0044] In some embodiments, the solvent supply device 9 includes a solvent tank 91, the solvent supply tank 91 having a plurality of solvent outlets, the first solvent outlet of the solvent tank 91 being connected to the first solvent inlet 112 of the screw extruder 1 via a metering pump 6 and a pipeline, the second solvent outlet of the solvent tank 91 being connected to the second solvent inlet 113 of the screw extruder 1 via a metering pump 6 and a pipeline, and the third solvent outlet of the solvent tank 91 being connected to the solvent inlet of the dynamic mixing device 2 via a metering pump 6 and a pipeline.

[0045] Optionally, the solvent supply device 9 may also include a solvent recovery device 92, which is used to collect the solvent volatilized during spinning, purify and condense the collected solvent, and store it.

[0046] In some embodiments, the dynamic mixing device 2 includes a housing 21 and a rotating motor 22. The upper part of the housing 21 is provided with a solvent inlet, a feed inlet, and a co-solvent inlet. The supercritical fluid device 5 continuously inputs supercritical fluid into the dynamic mixing device 2 through the co-solvent inlet. The bottom of the housing 21 is provided with a discharge outlet. The output end of the rotating motor 22 is connected to a rotating shaft 23. One end of the rotating shaft 23 extends into the housing 21. At least one inner wall of the housing 21 is provided with a plurality of guide plates 24 evenly distributed along the axial direction of the rotating shaft 23. The rotating shaft 23 is provided with a plurality of first stirring paddle groups 25 and a plurality of second stirring paddle groups 26 evenly distributed along its axial direction. The first stirring paddle groups 25 and the second stirring paddle groups 26 are alternately distributed along the axial direction of the rotating shaft 23.

[0047] In some embodiments, the first stirring paddle assembly 25 includes at least one first stirring paddle 251, one end of the first stirring paddle 251 is fixedly connected to the rotating shaft 23, and the other end of the first stirring paddle 251 is provided with at least one first baffle 252.

[0048] For example, the first stirring paddle assembly 25 includes two first stirring paddles 251 symmetrically arranged on both sides of the rotating shaft 23. One end of the first stirring paddle 251 is fixedly connected to the rotating shaft 23, and the other end of the first stirring paddle 251 is fixedly connected to two symmetrically arranged first baffles 252, which are triangular plate structures.

[0049] In some embodiments, the second agitator assembly 26 includes at least one second agitator 261, one end of which is fixedly connected to the rotating shaft 23, and the other end of which is provided with at least one second baffle 262.

[0050] For example, the second stirring paddle assembly 26 includes two second stirring paddles 261 symmetrically arranged on both sides of the rotating shaft 23. One end of the second stirring paddle 261 is fixedly connected to the rotating shaft 23, and the other end of the second stirring paddle is fixedly connected to two symmetrically arranged second baffles 262, which are triangular plate structures.

[0051] In some embodiments, the guide plate 24 is a bent structure, and the guide plate 24 and the inner wall of the housing 21 form an upward-opening groove and a downward-opening groove. The guide plate 24 is arranged between any two adjacent first stirring paddles 251 and second stirring paddles 252 in the axial direction of the rotating shaft 23.

[0052] In some embodiments, a first jacket 27 is provided outside the housing 21, and the first jacket 27 is provided with a heat transfer oil inlet and a heat transfer oil outlet.

[0053] The dynamic mixing device provided by this invention can further shorten the mixing time of polymer and solvent and improve the uniformity of polymer solution.

[0054] In some embodiments, the homogenization reaction device 3 includes a reaction vessel body 31 and a stirring assembly. The upper part of the reaction vessel body 31 is provided with a feed inlet, and the bottom of the reaction vessel body 31 is provided with a discharge outlet. The stirring assembly includes a stirring motor 32, a stirring shaft 33, and stirring blades 34. The output end of the stirring motor 32 is connected to one end of the stirring shaft 33, and the other end of the stirring shaft 33 extends into the reaction vessel 31 and rotates with the reaction vessel 31. The stirring blades 34 are located inside the reaction vessel 31 and are disposed on the stirring shaft 33.

[0055] In some embodiments, the outer wall of the reactor body 31 is provided with a second jacket 35, and the second jacket 35 is provided with a heat transfer oil inlet and a heat transfer oil outlet.

[0056] In this invention, the barrel 11, the housing 21, and the reaction vessel body 31 are all equipped with temperature sensors and pressure sensors.

[0057] In this invention, the spinning device is an existing electrospinning device. When electrospinning the spinning solution using the electrospinning device, a voltage is applied between the nozzle and the conductive mesh to form an electric field, causing the spinning solution to be ejected from the nozzle and the splitting baffle under pressure. The nozzle pressure (i.e., the spinning pressure) is controlled at 5-15 MPa, preferably 5-10 MPa. After the spinning solution is ejected, phase separation occurs due to the rapid pressure drop, forming a three-dimensional network fiber. As the fiber is guided by the fiber diffusion device to the surface of the conductive mesh to form an initial sheet.

[0058] Secondly, the present invention provides a supercritical electrostatic jetting continuous spinning method, which is implemented by the system provided in the first aspect.

[0059] The supercritical electrostatic jet spinning continuous spinning method includes the following steps: S1. Prepare materials, including polymers; S2. The material, the first organic solvent, and the second organic solvent are continuously fed into the screw extruder for melt mixing to obtain polymer solution A; S3. The polymer solution A obtained in step S2, the third organic solvent, and the co-solvent are continuously fed into the dynamic mixing device for stirring and mixing to obtain polymer solution B; the co-solvent is a supercritical fluid. S4. The polymer solution B obtained in step S3 is continuously fed into the homogenization reaction device for homogenization treatment to obtain the spinning solution. S5. The spinning solution obtained in step S4 is transported to the spinning device for spinning to obtain the initial sheet. S6. Heat and bond the initial sheet to obtain the sheet product; In step S2, the first organic solvent enters the barrel 11 of the screw extruder 1 through the first solvent inlet 112, and the second organic solvent enters the barrel 11 of the screw extruder 1 through the second solvent inlet 113.

[0060] The total input flow rate is the sum of the input flow rates of the material, the first organic solvent, the second organic solvent, the third organic solvent, and the co-solvent, and the percentage of the input flow rate of the material in the total input flow rate is no more than 20%.

[0061] In some implementations, the material input flow rate in step S2 is 100-200 kg / h.

[0062] In this application, the total input flow rate is the sum of the input flow rates of the material, the first organic solvent, the second organic solvent, the third organic solvent, and the co-solvent. In some embodiments, the input flow rate of the first organic solvent accounts for 10-35 wt% of the total input flow rate, the input flow rate of the second organic solvent accounts for 10-35 wt% of the total input flow rate, the input flow rate of the third organic solvent accounts for 10-60 wt% of the total input flow rate, the input flow rate of the co-solvent accounts for 5-20 wt% of the total input flow rate, and the input flow rate of the material accounts for 5-20 wt% of the total input flow rate.

[0063] For example, the percentage of the input flow rate of the first organic solvent to the total input flow rate can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, or a range of any two of these values.

[0064] For example, the percentage of the input flow rate of the second organic solvent to the total input flow rate is 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or any two of these values.

[0065] For example, the percentage of the input flow rate of the third organic solvent to the total input flow rate can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, or a range of any two sets of values ​​therein.

[0066] For example, the percentage of the input flow rate of the co-solvent to the total input flow rate can be 5 wt%, 10 wt%, 15 wt%, 20 wt%, or a range of any two of these values.

[0067] For example, the percentage of the material’s input flow rate to the total input flow rate can be 5 wt%, 10 wt%, 15 wt%, 20 wt%, or a range of any two of these values.

[0068] In some embodiments, the input flow rate of the first organic solvent accounts for 15-30 wt% of the total input flow rate, the input flow rate of the second organic solvent accounts for 15-30 wt% of the total input flow rate, the input flow rate of the third organic solvent accounts for 20-50 wt% of the total input flow rate, the input flow rate of the co-solvent accounts for 10-15 wt% of the total input flow rate, and the input flow rate of the material accounts for 10-15 wt% of the total input flow rate. When the input flow rates of each component meet the above conditions, the prepared sheet product has better fiber uniformity and mechanical properties.

[0069] In some embodiments, the sum of the input flow rates of the first organic solvent, the second organic solvent, and the third organic solvent accounts for 65 to 85 wt% of the total input flow rate.

[0070] For example, the mass percentage of the sum of the input flow rates of the first organic solvent, the second organic solvent, and the third organic solvent to the total input flow rate can be 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, or a range consisting of any two of these values.

[0071] In some embodiments, the sum of the input flow rates of the first organic solvent and the second organic solvent accounts for 20 to 70 wt% of the total input flow rate.

[0072] For example, the mass percentage of the sum of the input flow rates of the first organic solvent and the second organic solvent to the total input flow rate can be 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, or a range of any two sets of values ​​therein.

[0073] In some embodiments, the sum of the input flow rates of the first, second, and third organic solvents accounts for 70-80 wt% of the total input flow rate, and the sum of the input flow rates of the first and second organic solvents accounts for 30-60 wt% of the total input flow rate. When the input flow rates of the first, second, and third organic solvents meet the above conditions, the prepared sheet product has better fiber uniformity and mechanical properties.

[0074] In some embodiments, the first organic solvent, the second organic solvent, and the third organic solvent are preferably the same organic solvent.

[0075] In some embodiments, the weight-average molecular weight of the polymer is not less than 100,000.

[0076] The weight-average molecular weight of the polymer was determined using gel permeation chromatography.

[0077] In some embodiments, the weight-average molecular weight of the polymer is 100,000 to 4.2 million. Exemplarily, the weight-average molecular weight of the polymer can be 100,000, 300,000, 500,000, 800,000, 1,000,000, 1,500,000, 2,000,000, 2,500,000, 3,000,000, 3,500,000, 4,000,000, 4,200,000, or a range consisting of any two sets of values.

[0078] In some embodiments, the polymer includes, but is not limited to, at least one of polyethylene and polypropylene.

[0079] In this invention, the co-solvent is a supercritical fluid, which refers to a fluid that exceeds its critical point temperature and critical point pressure. When the supercritical fluid is above its critical point temperature, no amount of pressure can cause it to undergo phase transformation. This critical point temperature is the critical temperature of the supercritical fluid.

[0080] In some embodiments, the supercritical fluid includes at least one of supercritical ethane, supercritical heptane, supercritical carbon dioxide, supercritical nitrogen, supercritical nitric oxide, supercritical sulfur hexafluoride, supercritical ammonia, and supercritical dichlorodifluoromethane.

[0081] In some embodiments, the organic solvent includes at least one of alkanes, alkenes, cycloalkanes, haloalkanes, and haloalkenes; the alkanes include at least one of n-pentane and n-hexane; the olefins include ethylene; the cycloalkanes include at least one of cyclopentane and cyclohexane; the haloalkanes include at least one of dichloroethane, trichloroethane, dichloromethane, and carbon tetrachloride; and the haloalkenes include at least one of dichloroethylene and trichloroethylene.

[0082] In some embodiments, the material further includes an electrostatic enhancer, wherein the mass ratio of the electrostatic enhancer to the polymer is (1-40):100.

[0083] In some embodiments, the electrostatic enhancer includes at least one of stearic acid type compounds, sulfonic acid type compounds, quaternary ammonium type compounds, polar organic polymers, conductive inorganic particles, and semiconductor inorganic particles.

[0084] In some embodiments, the stearic acid-type compound includes stearates, which include at least one of magnesium stearate and zinc stearate.

[0085] In some embodiments, the sulfonic acid compound includes a sulfonate, which includes at least one of sodium dodecylbenzenesulfonate and sodium diisooctyl succinate sulfonate.

[0086] In some embodiments, the quaternary ammonium compound comprises a quaternary ammonium salt, which includes at least one of hexadecyltrimethylammonium bromide and octadecyltrimethylammonium chloride.

[0087] In some embodiments, the polar organic polymer comprises a grafted polyolefin, which includes at least one of maleic anhydride grafted polyolefin, acrylic acid grafted polyolefin, and ethylene-vinyl acetate copolymer (EVA) grafted polyolefin.

[0088] In some embodiments, the polyolefin includes at least one of polypropylene and polyethylene; the grafting rate of the grafted polyolefin is 0.1-5%, more preferably 0.5-2%. It should be noted that the grafting rate of the grafted polyolefin can be confirmed in the following way: Fourier transform infrared spectroscopy is used to test the characteristic absorption peaks of the infrared spectrum of a sample with a fixed thickness, and the grafting rate can be calculated by comparing the ratio of the absorption intensity of the grafted groups.

[0089] In some embodiments, the conductive inorganic particles include at least one of carbon-based conductive inorganic particles and metal conductive particles; the metal conductive particles include at least one of silver particles, gold particles, and copper particles; the carbon-based conductive inorganic particles include at least one of carbon nanotubes or modified particles thereof, graphene or modified particles thereof, and graphite or modified particles thereof.

[0090] In some embodiments, the semiconductor inorganic particles comprise tourmaline.

[0091] In some embodiments, the material further includes other additives, wherein the mass ratio of the other additives to the polymer is (0.5-10):100; the other additives may include antioxidants.

[0092] In some embodiments, the antioxidant is at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0093] In some embodiments, the hindered phenolic antioxidant includes at least one of 2,6-di-tert-butyl-4-methylphenol, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate (antioxidant 1076 for short) and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010 for short).

[0094] In some embodiments, the phosphite antioxidant includes at least one of tris(2,4-dimethylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(dodecyl) phosphite, tris(octadecyl) phosphite, and trithios(dodecyl) trithiophosphite.

[0095] In some embodiments, in step S2, the conditions for melt mixing are: the screw extruder speed is 200-500 r / min, the screw extruder temperature is 120-240°C, and the screw extruder pressure is 10-15 MPa.

[0096] In some embodiments, in step S2, the temperature of each zone of the screw extruder is: 120-130°C for zones 1 to 3, 220-240°C for zones 4 to 9, and 200-220°C for zones 10 to N.

[0097] In some embodiments, the stirring and mixing conditions in step S3 are: a rotation speed of 100-200 rpm, a temperature of 200-220°C, and a residence time of 20-40 min.

[0098] In some embodiments, in step S4, the conditions for the homogenization reaction are: rotation speed of 150-300 rpm, temperature of 200-220°C, and residence time of 0.5-2 h.

[0099] In some embodiments, in step S5, the spinning conditions are: a spinneret pressure of 5-15 MPa, a spinneret temperature of 200-220°C, a spinning voltage of 10-100 kV, a transmission speed of 0.5-5 m / min for the conductive collection device, and a receiving distance of 10-120 cm.

[0100] The present invention provides the following embodiments to facilitate understanding of the invention. These embodiments are provided not to limit the scope of the claims.

[0101] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0102] Examples 1-12 and Comparative Examples 1-5 below were implemented using a supercritical electrostatic jet continuous spinning system, such as Figures 1-7 As shown, the supercritical electrostatic jet continuous spinning system includes a screw extruder 1, a dynamic mixing device 2, a homogenization reaction device 3, a spinning device 4, a supercritical fluid supply device 5, a material conveying device 8, and a solvent supply device 9. The output end of the screw extruder 1 is connected to the inlet of the dynamic mixing device 2 through a pipe and a metering pump 6. The outlet of the dynamic mixing device 2 is connected to the inlet of the homogenization reaction device 3 through a pipe and a metering pump 6. The outlet of the homogenization reaction device 3 is connected to the spinning chamber of the spinning device 4 through a pipe. Material conveying device 8 is used to convey material to screw extruder 1; Solvent supply device 9 is connected to screw extruder 1 to supply organic solvent to screw extruder 1; Solvent supply device 9 is connected to dynamic mixing device 2 to supply organic solvent to dynamic mixing device 2; The output end of the supercritical fluid supply device 5 is connected to the dynamic mixing device 2 to supply supercritical fluid to the dynamic mixing device 2.

[0103] A filter 7 is installed on the pipe between the outlet of the dynamic mixing device 2 and the inlet of the homogenization reaction device 3. A filter 7 is also installed on the pipe between the outlet of the homogenization reaction device 3 and the spinning device 4.

[0104] The screw extruder 1 includes a barrel 11, a screw drive motor 12, and a screw 13. The screw 13 is disposed inside the barrel 11, and one end of the screw 13 is connected to the screw drive motor 12. The barrel 11 has a material inlet 111, a first solvent inlet 112, and a second solvent inlet 113. A material conveying device 8 is connected to the material inlet 111 of the barrel 11. The barrel 11 is provided with N processing zones in sequence along the forward direction of the screw 13, namely the first zone to the Nth zone, where N is 16. The lengths of the N processing zones are the same. The material inlet 111 is located in the first zone of the barrel 11, the first solvent inlet 112 is located in the fourth zone of the barrel 11, and the second solvent inlet 113 is located in the eighth zone of the barrel 11. The screw 13 located in the first to third zones is provided with a plurality of screws along the axial direction of the screw 13. The first meshing blocks 14 are arranged sequentially, and the torsion angle between any two adjacent first meshing blocks 14 is 45°; the screw 13 located in the fourth to ninth zones is provided with a plurality of first toothed discs 15 evenly distributed along the axial direction of the screw 13; the screw 13 located in the tenth to Nth zones is provided with a plurality of meshing block groups and a plurality of toothed disc groups, the meshing block groups and toothed disc groups are alternately distributed along the axial direction of the screw 13, each meshing block group has three second meshing blocks 16 arranged sequentially along the axial direction of the screw 13, and the torsion angle between any two adjacent second meshing blocks 16 in each meshing block group is 45°, each toothed disc group has seven second toothed discs 17 evenly distributed along the axial direction of the screw 13; the processing area is equipped with a heating device, which is used to regulate the temperature of the processing area. The heating device includes an electric heater disposed inside the barrel 11, a temperature sensor disposed inside the barrel, and a temperature controller disposed outside the barrel 11. The temperature controller is electrically connected to the electric heater and the temperature sensor, respectively. The electric heater is an electric heating rod. The length-to-diameter ratio of the screw extruder 1 is 48:1.

[0105] The material conveying device 8 includes a material tank 81 and a screw conveyor 82. The material outlet of the material tank 81 is connected to the material inlet 111 of the barrel 11 through a conveying pipe.

[0106] The solvent supply device 9 includes a solvent tank 91. The solvent tank 91 has multiple solvent outlets. The first solvent outlet of the solvent tank 91 is connected to the first solvent inlet 112 of the screw extruder 1 via a metering pump 6 and a pipeline. The second solvent outlet of the solvent tank 91 is connected to the second solvent inlet 113 of the screw extruder 1 via a metering pump 6 and a pipeline. The third solvent outlet of the solvent tank 91 is connected to the solvent inlet of the dynamic mixing device 2 via a metering pump 6 and a pipeline.

[0107] The dynamic mixing device 2 includes a housing 21 and a rotating motor 22. The upper part of the housing 21 is provided with a solvent inlet, a feed inlet, and a co-solvent inlet. In use, the organic solvent in the solvent tank 91 is continuously input into the dynamic mixing device 2 through the solvent inlet. The output end of the supercritical fluid supply device 5 is connected to the co-solvent inlet of the dynamic mixing device 2 through a pipe. In use, the supercritical fluid device 5 continuously inputs supercritical fluid into the dynamic mixing device 2 through the co-solvent inlet. The bottom of the housing 21 is provided with a discharge port. The output end of the rotating motor 22 is connected to a rotating shaft 23. One end of the rotating shaft 23 extends into the housing 21. At least one inner wall of the housing 21 is provided with a plurality of guide plates 24 evenly distributed along the axial direction of the rotating shaft 23. The rotating shaft 23 is provided with a plurality of first stirring paddle groups 25 and a plurality of second stirring paddle groups 26 evenly distributed along its axial direction. The first stirring paddle groups 25 and the second stirring paddle groups 26 are alternately distributed along the axial direction of the rotating shaft 23. The first impeller assembly 25 includes two first impellers 251 symmetrically arranged on both sides of the rotating shaft 23. One end of the first impeller 251 is fixedly connected to the rotating shaft 23, and the other end of the first impeller 251 is fixedly connected to two symmetrically arranged first baffles 252, which are triangular plate structures. The second impeller assembly 26 includes two second impellers 261 symmetrically arranged on both sides of the rotating shaft 23. One end of the second impeller 261 is fixedly connected to the rotating shaft 23, and the other end of the second impeller is fixedly connected to two symmetrically arranged second baffles 262, which are triangular plate structures. The guide plate 24 is a bent structure. The guide plate 24 and the inner wall of the housing 21 form an upward-opening groove and a downward-opening groove. The guide plate 24 is arranged between any two adjacent first impellers 251 and second impellers 261 along the axial direction of the rotating shaft 23. A first jacket 27 is provided outside the housing 21. The first jacket 27 is provided with a heat transfer oil inlet and a heat transfer oil outlet.

[0108] The homogenization reaction device 3 includes a reaction vessel body 31 and a stirring assembly. The upper part of the reaction vessel body 31 is provided with a feed inlet. The discharge port of the dynamic mixing device 2 is connected to the feed inlet of the homogenization reaction device 3 through a pipe and a metering pump 6. The bottom of the reaction vessel body 31 is provided with a discharge port. The discharge port of the homogenization reaction device 3 is connected to the feed end of the spinning device 4 through a pipe and a filter 7. The stirring assembly includes a stirring motor 32, a stirring shaft 33, and stirring blades 34. The output end of the stirring motor 32 is connected to one end of the stirring shaft 33. The other end of the stirring shaft 33 extends into the reaction vessel 31 and rotates with the reaction vessel 31. The stirring blades 34 are located inside the reaction vessel 31 and are mounted on the stirring shaft 33. A second jacket 35 is provided on the outer wall of the reaction vessel body 31. The second jacket 35 is provided with a heat transfer oil inlet and a heat transfer oil outlet.

[0109] In this embodiment, temperature sensors and pressure sensors are installed inside the barrel 11, the housing 21, and the reaction vessel body 31.

[0110] Examples 1-12 and Comparative Examples 1-4 The embodiments and comparative examples of the present invention provide a supercritical electrostatic jetting continuous spinning method, comprising the following steps: S1, mixing the components of the material according to the mass ratio of each component in Table 1 to obtain the material; S2. The material, the first organic solvent, and the second organic solvent are continuously fed into the screw extruder 1 for melt mixing to obtain polymer solution A; S3. The polymer solution A obtained in step S2, the third organic solvent and the co-solvent are continuously fed into the dynamic mixing device 2 for stirring and mixing to obtain polymer solution B; S4. The polymer solution B obtained in step S3 is continuously fed into the homogenization reaction device 3 for homogenization treatment to obtain spinning solution; S5. The spinning solution obtained in step S4 is transported to the spinning device 4 for spinning to obtain the initial sheet. S6. Heat and bond the initial sheet to obtain the sheet product.

[0111] Step S5 uses an existing electrospinning device 4. When electrospinning the spinning solution using this device, a voltage is applied between the nozzle and the conductive mesh curtain to create an electric field. This causes the spinning solution to be ejected from the nozzle and the fiber separating baffle under pressure. After ejection, the spinning solution undergoes phase separation due to rapid pressure drop, forming a three-dimensional network of fibers. These fibers are then guided to the surface of the conductive mesh curtain by a fiber diffusion device to form an initial sheet. In step S5, the spinning conditions are: a spinning pressure of 10 MPa, a spinning temperature of 210°C, a spinning voltage of 60 kV, a distance (i.e., receiving distance) between the nozzle and the conductive mesh curtain of 50 cm, and a transmission rate of 3 m / min for the conductive mesh curtain.

[0112] Polymer: High-density polyethylene (HDPE), grade TR-144, manufactured by Sinopec, weight average molecular weight 180,000.

[0113] The co-solvent is supercritical carbon dioxide; The electrostatic enhancer is hexadecyltrimethylammonium bromide; The first organic solvent, the second organic solvent, and the third organic solvent are all 1,2-dichloroethane; The antioxidants are tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168) and pentaerythritol tetrakis([β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), with a mass ratio of 1:1.

[0114] In this embodiment, the flow rate of the material input screw extruder is 150 kg / h. The input flow rates of the first organic solvent, the second organic solvent, the third organic solvent, and the cosolvent can be adjusted by the metering pump on the corresponding pipeline.

[0115] In step S2, the temperature of each processing zone in the screw extruder is: 120°C for zones 1 to 3, 230°C for zones 4 to 9, and 210°C for zones 10 to N; the screw speed of the screw extruder is 400 r / min, and the pressure is 12 MPa.

[0116] In step S2, the first organic solvent enters the screw extruder 1 through the first solvent inlet 112, and the second organic solvent enters the screw extruder 1 through the second solvent inlet 113.

[0117] In step S3, the stirring and mixing conditions are: a rotation speed of 150 rpm, a temperature of 210°C, and a residence time of 30 min.

[0118] In step S4, the conditions for the homogenization reaction are: rotation speed of 200 rpm, temperature of 210°C, and residence time of 1 h.

[0119] The mass ratios of the electrostatic enhancer, antioxidant, and polymer in the material are shown in Table 1. The total input flow rate is the sum of the input flow rates of the material, the first organic solvent, the second organic solvent, the third organic solvent, and the co-solvent. The percentage of the input flow rate of the first organic solvent to the total input flow rate is Q1, the percentage of the input flow rate of the second organic solvent to the total input flow rate is Q2, the percentage of the input flow rate of the third organic solvent to the total input flow rate is Q3, the percentage of the input flow rate of the co-solvent to the total input flow rate is Q4, and the percentage of the input flow rate of the material to the total input flow rate is Q5. Q1, Q2, Q3, Q4, and Q5 are shown in Tables 1 and 2.

[0120] Comparative Example 5 The difference between this comparative example and Example 1 is that in the supercritical electrostatic jet continuous spinning system used in this comparative example, the output end of the supercritical fluid supply device 5 is connected to the first solvent inlet 112 of the screw extruder through a metering pump and a pipeline. In this comparative example, supercritical fluid carbon dioxide is not input in step S3, but in step S2, supercritical fluid carbon dioxide and the first organic solvent are simultaneously input into the screw extruder 1 through the first solvent inlet 112.

[0121] In the above embodiments and comparative examples, the performance of the fibers or sheets was tested, and the test results are shown in Tables 1 and 2. The test methods are as follows: (1) Average fiber diameter: The average fiber diameter was calculated by taking pictures of the fibers with SEM and randomly measuring the diameter of 100 fibers. (2) Tensile strength: The test was conducted according to standard ISO13934-1-2013. The transverse and longitudinal tensile strength of the sheet sample was tested. The basis weight of the sheet sample was 70 GSM, and the average value of 10 sheet samples was taken. (3) Spinning weight CV value: During the continuous electrospinning process, collect all the fibers obtained from spinning for 12 seconds and weigh them. Collect the fibers and weigh them 10 times according to the above steps. After obtaining 10 weight data, calculate the spinning weight CV value: Spinning weight CV value = standard deviation of total fiber weight / arithmetic mean of total fiber weight × 100%.

[0122] Table 1 Table 2 Note: "0" in Table 2 indicates that the corresponding component was not entered in the corresponding step.

[0123] The embodiments of the present invention realize continuous feeding and continuous dissolution of polymers under ≤15MPa conditions, realize continuous production process of supercritical electrostatic jet spinning, and obtain fiber products of excellent quality; the average diameter of the fibers obtained by electrospinning is not greater than 2.31μm, the spinneret weight CV value is not greater than 10%, and the tensile strength of the prepared fiber sheet is not less than 201N, which shows that the sheet products prepared by the method of the present invention have excellent mechanical properties and excellent fiber uniformity.

[0124] Compared with Example 6, Comparative Examples 1 and 2, which have the same material input flow rate, did not input organic solvent in step S2, and Comparative Example 3 did not input organic solvent into the dynamic mixing device in step S3. This resulted in a worse mixing effect of the components in the spinning solution, which in turn led to an increase in the average fiber diameter, a significant increase in the spinneret weight CV value, and a significant decrease in the mechanical properties of the sheet product.

[0125] Compared with the embodiments, in Comparative Example 4, no supercritical fluid carbon dioxide was introduced in step S3, which resulted in a significant increase in the average fiber diameter and the spinneret weight CV value, and a significant decrease in the mechanical properties of the sheet product.

[0126] Compared with the embodiments, in Comparative Example 5, supercritical fluid carbon dioxide was not introduced in step S3. Instead, in step S2, supercritical fluid carbon dioxide and the first organic solvent were simultaneously introduced into the screw extruder 1 through the first solvent inlet 112, which resulted in a significant increase in the average fiber diameter and the spinneret weight CV value, and a deterioration in the mechanical properties of the resulting sheet product.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A supercritical electrostatic jet continuous spinning system, characterized by, The device comprises a screw extruder, a dynamic mixing device, a homogenizing reaction device, a spinning device, a supercritical fluid supply device, a material conveying device and a solvent supply device, wherein the discharge end of the screw extruder is connected with the feeding port of the dynamic mixing device, the discharge port of the dynamic mixing device is connected with the feeding port of the homogenizing reaction device, and the discharge port of the homogenizing reaction device is connected with the spinning device. The material conveying device is used for conveying the material to the screw extruder, and the material comprises a polymer. The solvent supply device is connected with the screw extruder to convey the organic solvent to the screw extruder. The solvent supply device is connected with the dynamic mixing device to convey the organic solvent to the dynamic mixing device. The supercritical fluid supply device is connected with the dynamic mixing device to convey the supercritical fluid to the dynamic mixing device.

2. The supercritical electrostatic spraying continuous spinning system of claim 1, wherein, The screw extruder comprises a first solvent inlet and a second solvent inlet, and the solvent supply device is connected with the first solvent inlet and the second solvent inlet of the screw extruder through pipes to convey the organic solvent to the screw extruder through the first solvent inlet and the second solvent inlet.

3. The supercritical electrostatic spraying continuous spinning system of claim 2, wherein, The screw extruder comprises a barrel, a screw driving motor and a screw, the screw is arranged in the barrel, one end of the screw is connected with the screw driving motor, and the barrel is sequentially provided with N processing regions in the advancing direction of the screw, which are respectively a first region to an Nth region, and N is a positive integer of 16-20. The barrel has a material inlet, the material inlet is arranged in the first region of the barrel, and the material conveying device is connected with the material inlet of the barrel. The first solvent inlet is arranged in any one of the fourth region to the sixth region of the barrel, the second solvent inlet is arranged in any one of the eighth region to the ninth region of the barrel, the solvent supply device is connected with the first solvent inlet of the barrel through a pipe and a metering pump, and the solvent supply device is connected with the second solvent inlet of the barrel through a pipe and a metering pump.

4. The supercritical electrostatic spraying continuous spinning system of claim 1, wherein, A filter is arranged on the pipe between the outlet of the dynamic mixing device and the inlet of the homogenizing reaction device. And / or, a filter is arranged on the pipe between the outlet of the homogenizing reaction device and the spinning device.

5. A supercritical electrostatic jet continuous spinning method characterized by, The device comprises the following steps: S1, preparing a material, wherein the material comprises a polymer; S2, continuously inputting the material, a first organic solvent and a second organic solvent into the screw extruder to perform melt mixing, to obtain a polymer solution A; S3, continuously inputting the polymer solution A obtained in step S2, a third organic solvent and a cosolvent into the dynamic mixing device to perform stirring mixing, to obtain a polymer solution B, wherein the cosolvent is a supercritical fluid; S4, continuously inputting the polymer solution B obtained in step S3 into the homogenizing reaction device to perform homogenizing treatment, to obtain a spinning solution; S5, conveying the spinning solution obtained in step S4 to the spinning device to perform spinning, to obtain an initial sheet; S6, heating and bonding the initial sheet, to obtain a sheet product. The total input flow is the sum of the input flow of the material, the first organic solvent, the second organic solvent, the third organic solvent and the cosolvent, and the percentage of the input flow of the material in the total input flow is not more than 20%.

6. The supercritical electrostatic jet continuous spinning method according to claim 5, wherein, The percentage of the input flow of the first organic solvent in the total input flow is 10-35wt%, the percentage of the input flow of the second organic solvent in the total input flow is 10-35wt%, the percentage of the input flow of the third organic solvent in the total input flow is 10-60wt%, the percentage of the input flow of the cosolvent in the total input flow is 5-20wt%, and the percentage of the input flow of the material in the total input flow is 5-20wt%. The first organic solvent, the second organic solvent and the third organic solvent are preferably the same organic solvent.

7. The supercritical electrostatic spraying continuous spinning method according to claim 5, wherein The material further comprises an electrostatic enhancer, and the mass ratio of the electrostatic enhancer to the polymer is (1-40):

100. The material further comprises other additives, and the mass ratio of the other additives to the polymer is (0.5-10):

100.

8. The supercritical electrostatic spraying continuous spinning method according to claim 5, wherein The barrel of the screw extruder is provided with a material inlet, a first solvent inlet and a second solvent inlet, and is sequentially provided with N processing zones, i.e. first zone to Nth zone, along the advancing direction of the screw of the screw extruder, wherein N is a positive integer of 16-20; the material inlet is located in the first zone of the barrel, the first solvent inlet is located in any one of the fourth zone to the sixth zone of the barrel, and the second solvent inlet is located in any one of the eighth zone to the ninth zone of the barrel. In step S2, the first organic solvent enters the screw extruder through the first solvent inlet, and the second organic solvent enters the screw extruder through the second solvent inlet.

9. The supercritical electrostatic spraying continuous spinning method according to claim 5, wherein In step S2, the melting and mixing conditions are as follows: the rotation speed of the screw extruder is 200-500r / min, the temperature of the screw extruder is 120-240℃, and the pressure of the screw extruder is 10-15MPa. In step S3, the stirring and mixing conditions are as follows: the rotation speed is 100-200rpm, the temperature is 200-220℃, and the residence time is 20-40min. In step S4, the homogenization reaction conditions are as follows: the rotation speed is 150-300rpm, the temperature is 200-220℃, and the residence time is 0.5-2h. In step S5, the spinning conditions are as follows: the spinning pressure is 5-15MPa, the spinning temperature is 200-220℃, the spinning voltage is 10-100kV, the transmission speed of the conductive collection device is 0.5-5m / min, and the receiving distance is 10-120cm.

10. A supercritical electrostatic jet continuous spinning method, characterized by, The supercritical electrostatic jet continuous spinning system is implemented by the method according to any one of claims 1-4.

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