Electrostatic spinning collecting device capable of realizing precise humidity control and uniform collection

Abstract

The invention relates to an electrostatic spinning collection device capable of realizing precise humidity control and uniform collection, which comprises a collection conveyor belt, an exhaust unit, a heating unit and a heat transfer unit, a heating coil of the heating unit, a heat transfer chamber of the heat transfer unit and an isolation soft plate are arranged between an upper mesh belt and a lower mesh belt of the collection conveyor belt; the heating coil and the heat transfer chamber are both arranged above the isolation soft plate, and the isolation soft plate divides the space between the bottom surface of the heat transfer chamber and the lower-layer mesh belt into a plurality of control spaces; the heating unit supplies heat to all the control spaces and the lower-layer mesh belt through the heat transfer unit; the air exhaust unit comprises a plurality of air exhaust devices, the air exhaust devices correspond to the control spaces one to one, each air exhaust device comprises an air exhaust opening, an air exhaust pipe and an air exhaust fan, the air exhaust openings communicate with the corresponding control spaces, the air exhaust pipes are arranged above the isolation soft plates, the air exhaust fans are arranged on the outer side of the collection conveying belt and used for exhausting air in the corresponding control spaces, and negative pressure is formed in the control spaces; and the solvent can be pumped away by the exhaust fan through the control space.

Description

Technical Field

[0001] The invention belongs to the technical field of nanofiber collection, and in particular relates to an electrospinning collection device capable of achieving precise moisture control and uniform collection. Background Art

[0002] Electrospinning refers to the process in which a polymer solution forms a jet under the action of high-voltage static electricity, and then is gradually stretched under the action of the electrostatic force field. Due to the small size effect, the water or organic solvent in the jet evaporates instantly, and the polymer fibers stretched to a nanometer form are deposited on the collector to form a polymer nanofiber membrane. The nanofiber membrane prepared by electrospinning can be used in protective filtration, industrial catalysis, energy batteries, biomedicine and other fields. However, the basis of these applications lies in the effective optimization of nanofiber morphology and the effective regulation of membrane uniformity, which puts higher requirements on the electrospinning collection device.

[0003] At present, electrospinning collection devices include flat plate collectors, drum collectors, chain collectors, flexible steel plate collectors, mesh belt collectors, etc. Flat plate collectors, drum collectors and flexible steel plate collectors have the problem of membrane deformation caused by uneven solvent volatilization. Chain collectors have the problem of insufficient collection flatness. Mesh belt collectors have the problem of edge effect. In large-scale industrial production, the adsorption of volatile solvents can also cause wrinkles in the macroscopic morphology of nanofiber membranes, affecting their applications.

[0004] In the face of the above problems, researchers have made many attempts. For example, in order to achieve uniform collection of fibers, edge warm air flow is used to assist; in order to achieve desorption of solvents in the jet and on the fibers, infrared lamps are used for heating and baking; in order to achieve high-speed deposition of nanofibers, dense exhaust devices are installed. However, such attempts also have corresponding problems. Edge warm air flow assistance increases the macroscopic disturbance of the electrostatic jet in the air, which easily causes fiber nodules and is not easy to regulate the overall uniformity of the fiber membrane; far-infrared heating at a certain distance causes baking unevenness itself; dense exhaust devices still have edge effects, and the fiber membrane is not easy to be evenly flat. Summary of the invention

[0005] In view of the above problems, the present invention provides an electrospinning collection device capable of achieving precise humidity control and uniform collection, comprising a collection conveyor belt, an exhaust unit, a heating unit and a heat transfer unit. A heating coil of the heating unit, a heat transfer chamber of the heat transfer unit and an isolation soft plate are arranged between the upper and lower mesh belts of the collection conveyor belt. The heating coil and the heat transfer chamber are both arranged above the isolation soft plate. The isolation soft plate divides the space between the bottom surface of the heat transfer chamber and the lower mesh belt into a plurality of control spaces. The heating unit uniformly supplies heat to all control spaces and the lower mesh belt through the heat transfer unit, thereby promoting uniform desorption and volatilization of the solvent.

[0006] The exhaust unit includes several groups of exhaust devices, which correspond to the control spaces one by one. The exhaust devices include exhaust ports, exhaust pipes and exhaust fans connected in sequence. The exhaust ports are connected to the corresponding control spaces. The exhaust pipes are arranged above the isolation soft plates. The exhaust fans are arranged on the outside of the collection conveyor belts to exhaust air for the corresponding control spaces, thereby forming a negative pressure in the control spaces, which is conducive to the gaseous solvent passing through the control spaces and being extracted by the exhaust fans.

[0007] Optionally, the collecting conveyor belt comprises a collecting mesh belt, two rolling shafts and a motor, the collecting mesh belt is evenly and densely covered with through holes, the collecting mesh belt is wound around two rolling shafts parallel to each other, the rolling shafts are connected to the motor to drive the rolling shafts to rotate, thereby driving the collecting mesh belt to move;

[0008] A plurality of first tracks are evenly arranged on the inner side of the collecting mesh belt, which are used to connect the heat transfer unit to achieve contact heat transfer and improve heat transfer efficiency; the first tracks are recessed toward the outer side of the collecting mesh belt, and the first tracks are parallel to each other and perpendicular to the rolling axis.

[0009] Further optionally, the collecting mesh belt is made of stainless steel, and the through holes on the collecting mesh belt are arranged in an orderly manner horizontally and vertically in a matrix distribution.

[0010] Further optionally, the rolling shaft is a tensioning shaft, the tensioning shaft is a polymer insulating material, and the two tensioning shafts are used to stretch the collecting mesh belt so that the lower mesh belt can remain horizontal, thereby ensuring uniform collection of the nanofibers.

[0011] Optionally, the heating unit includes a plurality of heating coils, connecting pipes and a heating device, the heating coils are distributed in a serpentine shape and are evenly coiled inside the heat transfer chamber, the two ends of the heating coils are respectively close to the two rolling shafts, and the two ends of the heating coils are respectively connected to the inlet and outlet of the heating device through the connecting pipes;

[0012] Several heating coils are stacked up and down to increase the heat supply; the heating coils are filled with heat-conducting silicone oil, and the heating device can heat the silicone oil and drive the silicone oil to circulate in the heating coils.

[0013] Optionally, the isolation soft plate includes a plurality of isolation plates that cross each other horizontally and vertically, the isolation plates are all arranged vertically, the tops of the isolation plates are connected to the lower surface of the heat transfer chamber, the horizontal isolation plates are parallel to the first track, and the vertical isolation plates are perpendicular to the first track;

[0014] A plurality of horizontally and vertically intersecting isolation plates are evenly arranged below the heat transfer chamber in a matrix arrangement, and the space between the bottom surface of the heat transfer chamber and the lower mesh belt is evenly divided into a plurality of control spaces of the same size.

[0015] Optionally, the heat transfer unit includes a heat transfer chamber, a heat transfer component and a heat transfer rod group, the heat transfer chamber is filled with silicone oil, the heat transfer component is arranged on the lower surface of the heat transfer chamber, the heat transfer component includes a plurality of heat transfer bars parallel to each other, the heat transfer bars are solid metal bars, and a second track is arranged on the lower surface of the heat transfer bar, the second track is parallel to the first track, and the second track corresponds to the first track up and down;

[0016] The heat transfer rod group includes a plurality of rows of heat transfer rods, each row of heat transfer rods corresponds to a second track, the top ends of the heat transfer rods are connected to the second track, and the bottom ends of the heat transfer rods are connected to the first track.

[0017] Further optionally, the heat transfer strip is a rectangular parallelepiped and is parallel to the first track, and the heat transfer strip runs through all longitudinal isolation plates; the second track is recessed upward, and the second track is located in the center of the heat transfer strip.

[0018] Further optionally, the heat transfer chamber is in the shape of a flat rectangular parallelepiped and is a horizontally arranged closed chamber, and the four sides of the heat transfer chamber are respectively close to the two rolling shafts and the two sides of the collecting mesh belt, so as to fully transfer heat to the collecting mesh belt; the two sides of the heat transfer chamber corresponding to the two sides of the collecting mesh belt are respectively provided with brackets, and the bottom of the brackets is connected to the support frame or the ground to support the heat transfer chamber;

[0019] A liquid level measuring device and a silicone oil expansion buffer are provided in the heat transfer chamber to detect the filling condition of the silicone oil in the heat transfer chamber and prevent the components from being compressed due to the thermal expansion of the silicone oil.

[0020] Optionally, a plurality of vertical air ducts are preset inside the heat transfer chamber, and upper and lower ends of the vertical air ducts are respectively connected to the top surface and the bottom surface of the heat transfer chamber, and the upper and lower ends of the vertical air ducts are open and connected to the external space of the heat transfer chamber;

[0021] The bottom end of the vertical air duct is an exhaust outlet and corresponds to the central position of a control space. The inlet of the exhaust duct is connected to the top of the vertical air duct through the outlet base, and the outlet of the exhaust duct is connected to the exhaust fan. The exhaust duct is parallel to the rolling axis, and the exhaust fan is arranged on the outer side of the collecting mesh belt, which does not affect the movement of the collecting mesh belt and does not occupy the space inside the collecting mesh belt.

[0022] Further optionally, a row of heat transfer rods includes a plurality of heat transfer rods arranged in a row, and the top and bottom ends of the heat transfer rods are respectively provided with spherical outwardly protruding clamping parts, which are respectively used to clamp into the second track and the first track, so that the heat transfer strip transfers heat to the lower mesh belt through the heat transfer rods, thereby realizing contact heat transfer and improving heat transfer efficiency;

[0023] The heat transfer strip and the heat transfer rod are both made of metal, such as stainless steel.

[0024] The heating device (such as a mold temperature controller) heats the heat-conducting silicone oil, then pumps it to the corresponding connecting pipe, and then inputs it into the corresponding heating coil. The heat-conducting silicone oil circulates in the serpentine heating coil and transfers the heat to the heat transfer bar. The heat transfer bar is a closed chamber, and the silicone oil sealed inside it is evenly heated. The heated silicone oil transfers the heat to the contact heat transfer rod through the metal wall of the heat transfer bar. After the heat transfer rod is heated, it transfers the heat to the lower mesh belt through contact conduction, thereby forming a temperature gradient zone in the mesh area of ​​the collection mesh belt. In this way, it is beneficial to the volatilization of the solvent in the polymer jet and the effective analysis of the adsorbed solvent of the nanofibers on the mesh belt, thereby achieving the purpose of optimizing the deposition morphology of the nanofibers and improving the nanofiber molding effect. The heating device and the corresponding pump can be set together for easy installation.

[0025] The spherical ends of the heat transfer rod are respectively inserted into the second track and the first track to form an embedded structure, thereby ensuring that when the collection mesh belt stops or moves, both ends of the heat transfer rod do not derail and maintain a good contact state. A row of heat transfer rods are densely arranged, and several rows of heat transfer rods are evenly arranged, and each row of heat transfer rods is connected to the corresponding first track to form a densely arranged heat conduction matrix, thereby ensuring efficient heat transfer efficiency. The non-conductive thermal conductive silicone and the insulating connecting pipe cut off the risk of current breakdown caused by high-voltage electrostatic discharge, thereby realizing contact-type uniform heat transfer under high-voltage static electricity.

[0026] In addition, although the two rolling shafts can stretch the collection mesh belt, when the collection mesh belt moves, the lower mesh belt will not be completely straight under the action of its own gravity, and will always fall to a certain extent, resulting in the distance between the lower mesh belt and the bottom surface of the heat transfer strip not being completely consistent. The top of the heat transfer rod of the present invention is spherical, so that the heat transfer rod can rotate within a certain range with its own top as the fulcrum and the bottom as the free end. The bottom end of the heat transfer rod is embedded in the first track. The bottom end of the heat transfer rod moves with the collection mesh belt, making the heat transfer rod tilt. When tilted to the limit, the top end of the heat transfer rod is stuck and no longer tilted to adapt to the change in the height position of the lower mesh belt.

[0027] In the present invention, accurate and effective exhaust control in each control space is used to ensure uniform deposition of the fiber membrane, avoid the uneven influence caused by the edge effect, and avoid membrane deformation caused by overall oversaturation / local oversaturation of the gas solvent. At the same time, the design of the heating unit and the heat transfer unit is coordinated to perform uniform temperature control, thereby ensuring the effective removal of the solvent in the entire fiber membrane and avoiding deformation of the fiber membrane caused by solvent accumulation. Through the above two points, the deposition efficiency of the fiber is effectively improved, and the uniform collection of the nanofiber membrane and the effective optimization of the macroscopic morphology are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of the electrospinning collection device capable of achieving precise moisture control and uniform collection;

[0029] Figure 2 Schematic diagram of the cooperation between the heating unit and the exhaust unit (I) (the upper surface of the heat transfer chamber is removed);

[0030] Figure 3 Schematic diagram (II) of the cooperation between the heating unit and the exhaust unit (the upper surface of the heat transfer chamber is removed);

[0031] Figure 4 is a schematic diagram of a heat transfer unit;

[0032] Figure 5 A schematic diagram of a heat transfer rod connecting the first track and the second track;

[0033] Figure 6 is a schematic diagram of the lower surface of the heat transfer chamber;

[0034] Figure 7 Schematic diagram of the control space built to isolate the flex board.

[0035] In the accompanying drawings, 1-collecting mesh belt, 2-rolling shaft, 3-motor, 4-isolation soft board, 5-control space, 6-exhaust duct, 7-exhaust fan, 8-first track, 9-second track, 10-support frame, 11-protective soft board, 12-heating coil, 13-connecting pipe, 14-heating device, 15-heat transfer chamber, 16-isolation plate, 17-exhaust port, 18-port base, 19-heat transfer strip, 20-heat transfer rod. DETAILED DESCRIPTION

[0036] This embodiment provides an electrospinning collection device that can achieve precise moisture control and uniform collection, such as Figure 1-Figure 7 As shown, it includes a collecting conveyor belt, an exhaust unit, a heating unit and a heat transfer unit. A heating coil 12 of the heating unit, a heat transfer chamber 15 of the heat transfer unit and an isolation soft plate 4 are arranged between the upper and lower mesh belts of the collecting conveyor belt. The heating coil and the heat transfer chamber are both arranged above the isolation soft plate 4. The isolation soft plate 4 divides the space between the bottom surface of the heat transfer chamber and the lower mesh belt into a plurality of control spaces 5. The heating unit uniformly supplies heat to all control spaces 5 and the lower mesh belt through the heat transfer unit, thereby promoting uniform desorption and volatilization of the solvent.

[0037] The exhaust unit includes several groups of exhaust devices, which correspond to the control space 5 one by one. The exhaust device includes an exhaust port 17, an exhaust pipe 6 and an exhaust fan 7 which are connected in sequence. The exhaust port 17 is connected to the corresponding control space 5. The exhaust pipe 6 is arranged above the isolation soft plate 4. The exhaust fan 7 is arranged on the outside of the collecting conveyor belt to exhaust air for the corresponding control space 5, so that a negative pressure is formed in the control space 5, which is conducive to the solvent passing through the control space 5 and being extracted by the exhaust fan 7.

[0038] The working principle of the electrospinning collection device described in the present invention is as follows: a spinneret is provided below the collecting conveyor belt, and the opening of the spinneret spins upward (i.e., toward the lower surface of the lower mesh belt) to spin, and the collecting conveyor belt can collect electrospun nanofibers in a moving or stopped state. As the collecting conveyor belt rotates, multi-layer collection of nanofibers can be achieved, and finally a nanofiber membrane is formed; the exhaust action of the exhaust unit forms a negative pressure in the control space 5, which not only enables the lower surface of the lower mesh belt to absorb the nanofibers and then move with the conveyor belt, but also promotes the desorption of the solvent on the fibers in the thermal environment provided by the heating unit and the heat transfer unit.

[0039] The isolation soft board 4 of the present invention cooperates with the lower mesh belt to divide the negative pressure area into a number of control spaces 5 to form an arbitrary local finite element area. Each control space 5 corresponds to a group of exhaust devices, which can achieve precise humidity control (i.e., control the solvent evaporation concentration) through the frequency of the motor 3 of the exhaust fan 7, and realize the control of the gas solvent concentration in each local area of ​​the collection conveyor belt, thereby realizing the control of the overall uniformity of the fiber membrane.

[0040] The present invention constructs a temperature control system in the collecting conveyor belt. The heating unit transfers heat to each control space 5 and the collecting conveyor belt through the heat transfer unit. Through matrix-type contact heat transfer, effective and uniform temperature control near the collecting conveyor belt is achieved, which is beneficial to the effective volatilization of the solvent in the jet during the electrospinning process, and promotes the effective decomposition of the solvent adsorbed by the nanofibers on the mesh belt, and then cooperates with the exhaust device of any local finite element area to achieve the optimization of the deposition morphology of the nanofiber membrane.

[0041] In addition, based on the configuration of the insulated exhaust duct 6, the insulated connecting pipe 13 (silicone hose for transmitting silicone oil) and the insulated collecting conveyor belt, the risk of current breakdown of the exhaust fan, heating device and collecting conveyor belt motor caused by high-voltage electrostatic discharge is cut off, thereby achieving precise control of contact-type uniform heat transfer and exhaust under high-voltage static electricity and smooth operation of the collecting conveyor belt.

[0042] Optionally, the collecting conveyor belt comprises a collecting mesh belt 1, two rolling shafts 2 and a motor 3, the collecting mesh belt 1 is evenly and densely covered with through holes, the collecting mesh belt 1 is wound around two mutually parallel rolling shafts 2, the rolling shafts 2 are connected to the motor 3, and are used to drive the rolling shafts 2 to rotate, thereby driving the collecting mesh belt 1 to move;

[0043] A plurality of first tracks 8 are evenly arranged on the inner side of the collecting mesh belt 1, which are used to connect the heat transfer unit to achieve contact heat transfer and improve heat transfer efficiency; the first tracks 8 are recessed toward the outer side of the collecting mesh belt 1, and the first tracks 8 are parallel to each other and perpendicular to the rolling axis 2.

[0044] Further optionally, the collecting mesh belt 1 is made of stainless steel, and the through holes on the collecting mesh belt 1 are arranged in order horizontally and vertically in a matrix distribution; the porosity of the collecting mesh belt 1 is not less than 30%, which is convenient for suction by the exhaust device.

[0045] Further optionally, the rolling shaft 2 is a tension shaft, the tension shaft is a polymer insulating material, and the two tension shafts are used to stretch the collection mesh belt 1 so that the lower mesh belt can be kept horizontal, thereby ensuring uniform collection of nanofibers. The non-metallic tension shaft can cut off the current generated by high-voltage static discharge from being transmitted to other components inside the collection conveyor belt, and can also prevent the current from being transmitted to the human body and causing electric shock.

[0046] Further optionally, a support frame 10 is provided under the collecting conveyor belt for supporting the electrospinning collection device; the support frame 10 is a traditional cubic frame, and a protective soft plate 11 is provided on both sides of the frame and respectively corresponds to the positions of the two rolling shafts 2. The protective soft plate 11 is located under the corresponding rolling shaft 2 and is used to assist in cutting off the current formed during high-voltage electrostatic discharge, avoiding the current from being transferred to other equipment near the support frame 10, and cutting off the electrostatic influence between adjacent electrospinning collection devices as a whole.

[0047] One rolling shaft is connected to the motor 3 (ie, the active rolling shaft), and the motor 3 is mounted on the support frame 10 , and the other rolling shaft is not connected to the motor 3 (ie, the driven rolling shaft).

[0048] Optionally, the heating unit includes a plurality of heating coils 12, connecting pipes 13 and heating devices 14, the heating coils 12 are distributed in a serpentine shape and are evenly coiled inside the heat transfer chamber 15, the two ends of the heating coils 12 are respectively close to the two rolling shafts 2, and the two ends of the heating coils 12 are respectively connected to the inlet and outlet of the heating device 14 through the connecting pipes 13;

[0049] Several heating coils 12 are stacked up and down to increase the heat supply; the heating coils 12 are filled with heat-conducting silicone oil, and the heating device 14 can heat the silicone oil and drive the silicone oil to circulate in the heating coils 12. Both ends of the heating coils pass through the side wall of the heat transfer chamber and are then connected to the connecting pipe.

[0050] Further optionally, the heating coil 12 is made of metal, such as stainless steel, copper pipe, carbon steel, which is conducive to transferring heat to the heat transfer unit; the connecting pipe 13 is a silicone hose to prevent static electricity from affecting the heating device 14.

[0051] Optionally, the isolation soft board 4 includes a plurality of isolation boards 16 that cross each other horizontally and vertically, and the isolation boards 16 are all arranged vertically, and the tops of the isolation boards 16 are connected to the lower surface of the heat transfer chamber 15, and the horizontal isolation boards are parallel to the first track 8, and the vertical isolation boards are perpendicular to the first track 8;

[0052] A plurality of horizontally and vertically intersecting isolation plates are evenly arranged below the heat transfer chamber 15 in a matrix arrangement, and the space between the bottom surface of the heat transfer chamber and the lower mesh belt is evenly divided into a plurality of control spaces 5 of the same size.

[0053] Further optionally, the bottom end of the isolation plate 16 is located above the lower mesh belt and may contact the lower mesh belt or have a very small gap with the lower mesh belt so as not to affect the movement of the collecting mesh belt 1; the inlet of the exhaust duct 6 and the heating coil 12 are both located inside the heat transfer chamber 15.

[0054] Further optionally, the isolation plate 16, protective soft plate 11 and tensioning shaft are all made of polymer insulating materials, such as PVC, polyester, nylon, polytetrafluoroethylene, to prevent electrostatic current from affecting other metal parts of the electrospinning collection device; the heat transfer chamber 15 is made of metal and has good thermal conductivity.

[0055] The isolation soft plate 4 and the lower surface of the heat transfer chamber 15 form any local finite element space (i.e., control space 5), and each control space 5 corresponds to a set of exhaust devices, which can draw the control space 5 into a negative pressure area. Below the lower mesh belt is the spinning area, and the solvent in the spinning area is drawn into the control space 5 with the air under the action of negative pressure, and then discharged through the exhaust fan 7. Since the entire area between the bottom of the heat transfer chamber and the lower mesh belt is divided into finite elements by evenly arranged horizontal and vertical isolation plates, under the control of the power of each exhaust fan 7, the exhaust in any local finite element space can be precisely controlled, thereby realizing the control of the efficiency and probability of nanofiber scattering on the lower mesh belt, and then realizing the control of the uniformity of the entire nanofiber spinning film. The exhaust pipe 6 is made of insulating material, which avoids the risk of current breakdown of the exhaust fan 7 caused by high-voltage electrostatic discharge.

[0056] Optionally, a corresponding exhaust port 17 is provided on the bottom surface of the heat transfer chamber corresponding to the center position of the control space 5, and an air port base 18 is provided above each exhaust port 17. The air port base 18 is provided, and the inlet end of the exhaust pipe 6 is connected to the top of the air port base 18 to prevent silicone oil in the heat transfer chamber from entering the exhaust pipe. The outlet end of the exhaust pipe 6 is connected to the exhaust fan 7; the exhaust pipe 6 is parallel to the rolling shaft 2, and the exhaust fan 7 is provided on the outer side of the collecting mesh belt 1, which does not affect the movement of the collecting mesh belt 1 and does not occupy the space inside the collecting mesh belt 1.

[0057] As a specific implementation method, two horizontal control spaces are separated by an isolation plate below the heat transfer chamber, each horizontal control space is parallel to the first track 8, and each horizontal row has a number of control spaces, and the number of control spaces are distributed in a matrix; the exhaust ducts corresponding to each horizontal control space extend to one side of the adjacent collecting mesh belt to connect to the exhaust fan outside the collecting mesh belt on that side; a row of exhaust fans is provided on each side of the collecting mesh belt; a row of exhaust fans is evenly distributed in the length direction of the collecting mesh belt; two air outlet bases in a vertical row correspond to each other (that is, they can be arranged in a straight line), so that the two exhaust ducts in a vertical row can be arranged in a straight line; a heating coil 12 is serpentinely arranged along the length and width directions of the collecting mesh belt, and bypasses the two air outlet bases 18 in each vertical row.

[0058] Optionally, the heat transfer unit includes a heat transfer chamber 15, a heat transfer component and a heat transfer rod group. The heat transfer chamber is filled with silicone oil. The heat transfer component is arranged on the lower surface of the heat transfer chamber. The heat transfer component includes a plurality of mutually parallel heat transfer bars 19. The heat transfer bars 19 are solid metal bars. A second track 9 is arranged on the lower surface of the heat transfer bar 19. The second track 9 is parallel to the first track 8. The second track 9 corresponds to the first track 8 up and down.

[0059] The heat transfer rod group includes a plurality of rows of heat transfer rods. Each row of heat transfer rods 20 corresponds to a second track 9 . The top ends of the heat transfer rods 20 are connected to the second track 9 , and the bottom ends are connected to the first track 8 .

[0060] Further optionally, the heat transfer strip 19 is a rectangular parallelepiped and is parallel to the first track 8 , and the heat transfer strip 19 runs through all longitudinal isolation plates; the second track 9 is recessed upward, and the second track 9 is located in the center of the heat transfer strip 19 .

[0061] Further optionally, the heat transfer chamber 15 is in the shape of a flat rectangular parallelepiped and is a horizontally arranged closed chamber, and the four sides of the heat transfer chamber are respectively close to the two rolling shafts and the two sides of the collecting mesh belt, so as to fully transfer heat to the collecting mesh belt; the heat transfer chamber is provided with brackets on the two sides corresponding to the two sides of the collecting mesh belt, and the bottom of the brackets is connected to the support frame 10 or the ground to support the heat transfer chamber;

[0062] A liquid level measuring device and a silicone oil expansion buffer are provided in the heat transfer chamber to detect the filling condition of the silicone oil in the heat transfer chamber 15 to prevent the components from being compressed due to the thermal expansion of the silicone oil.

[0063] Optionally, a plurality of vertical air ducts are preset inside the heat transfer chamber, and upper and lower ends of the vertical air ducts are respectively connected to the top surface and the bottom surface of the heat transfer chamber, and the upper and lower ends of the vertical air ducts are open and connected to the external space of the heat transfer chamber;

[0064] The bottom end of the vertical air duct is an exhaust port and corresponds to the center position of a control space. The inlet of the exhaust pipe is connected to the top of the vertical air duct through the air port base, and the outlet of the exhaust pipe is connected to the exhaust fan. The exhaust pipe is parallel to the rolling axis, and the exhaust fan is arranged on the outer side of the collection mesh belt, which does not affect the movement of the collection mesh belt and does not occupy the space inside the collection mesh belt. The heating coil 12 is coiled around the vertical air duct. Either of the above two forms of exhaust pipe connection to the heat transfer chamber can be selected.

[0065] Further optionally, a row of heat transfer rods includes a plurality of heat transfer rods 20 arranged in a row, and the top and bottom ends of the heat transfer rods are respectively provided with spherical outwardly protruding clamping parts, which are respectively used to clamp into the second track 9 and the first track 8, so that the heat transfer strip 19 transfers heat to the lower mesh belt through the heat transfer rods 20, thereby realizing contact heat transfer and improving heat transfer efficiency;

[0066] The heat transfer strip 19 and the heat transfer rod 20 are both made of metal, such as stainless steel.

[0067] The heating device 14 (such as a mold temperature controller) heats the heat-conducting silicone oil, and then pumps it to the corresponding connecting pipe 13, and then inputs it into the corresponding heating coil 12. The heat-conducting silicone oil circulates in the serpentine heating coil 12, and transfers heat to the silicone oil in the heat transfer chamber. The silicone oil is evenly heated, and then further transfers heat to the heat transfer strip 19, and the heat transfer strip 19 transfers heat to the contact heat transfer rod 20. After the heat transfer rod 20 is heated, it transfers heat to the lower mesh belt through contact conduction, thereby forming a temperature gradient zone in the mesh area of ​​the collection mesh belt 1. In this way, it is not only beneficial to the volatilization of the solvent in the polymer jet, but also beneficial to the effective analysis of the solvent adsorbed by the nanofibers on the mesh belt, so as to achieve the purpose of optimizing the deposition morphology of the nanofibers and improving the nanofiber molding effect. The heating device 14 and the corresponding pump can be set together for easy installation.

[0068] The spherical ends of the heat transfer rod 20 are respectively inserted into the second track 9 and the first track 8 to form an embedded structure, thereby ensuring that when the collection mesh belt 1 stops or moves, both ends of the heat transfer rod 20 do not derail and maintain a good contact state. A row of heat transfer rods 20 are densely arranged, and several rows of heat transfer rods 20 are evenly arranged, and each row of heat transfer rods 20 is connected to the corresponding first track 8, forming a densely arranged heat conduction matrix, thereby ensuring efficient heat transfer efficiency. The non-conductive thermal silicone oil and the insulating connecting pipe cut off the risk of current breakdown caused by high-voltage electrostatic discharge, thereby realizing contact-type uniform heat transfer under high-voltage static electricity.

[0069] In addition, although the two rolling shafts 2 can stretch the collection mesh belt 1, when the collection mesh belt 1 moves, the lower mesh belt will not be completely straight under the action of its own gravity, and will always fall to a certain extent, resulting in the distance between the lower mesh belt and the bottom surface of the heat transfer strip 19 not being completely consistent. The top of the heat transfer rod 20 of the present invention is spherical, so that the heat transfer rod 20 can rotate within a certain range with its own top as the fulcrum and the bottom as the free end. The bottom end of the heat transfer rod 20 is embedded in the first track 8. The bottom end of the heat transfer rod 20 moves with the collection mesh belt 1, so that the heat transfer rod 20 tilts. When the tilt reaches the limit, the top of the heat transfer rod 20 is stuck and no longer tilts to adapt to the change in the height position of the lower mesh belt.

[0070] In the present invention, accurate and effective exhaust control in each control space 5 is used to ensure uniform deposition of the fiber membrane, avoid the uneven influence caused by the edge effect, and avoid membrane deformation caused by overall oversaturation / local oversaturation of the gas solvent. At the same time, the design of the heating unit and the heat transfer unit is coordinated to perform uniform temperature control, thereby ensuring the effective removal of the solvent in the entire fiber membrane and avoiding deformation of the fiber membrane caused by solvent accumulation. Through the above two points, the deposition efficiency of the fiber is effectively improved, and the uniform collection of the nanofiber membrane and the effective optimization of the macroscopic morphology are achieved.

Claims

1. An electrospinning collection device capable of achieving precise moisture control and uniform collection, characterized in that: It includes a collecting conveyor belt, an exhaust unit, a heating unit and a heat transfer unit. A heating coil of the heating unit, a heat transfer chamber of the heat transfer unit and an isolation soft plate are arranged between the upper and lower mesh belts of the collecting conveyor belt. The heating coil and the heat transfer chamber are both arranged above the isolation soft plate. The isolation soft plate divides the space between the bottom surface of the heat transfer chamber and the lower mesh belt into a plurality of control spaces. The heating unit evenly supplies heat to all control spaces and the lower mesh belt through the heat transfer unit, thereby promoting even desorption and volatilization of the solvent. The exhaust unit includes several groups of exhaust devices, which correspond to the control spaces one by one. The exhaust devices include exhaust ports, exhaust pipes and exhaust fans connected in sequence. The exhaust ports are connected to the corresponding control spaces. The exhaust pipes are arranged above the isolation soft plates. The exhaust fans are arranged on the outside of the collection conveyor belts to exhaust air for the corresponding control spaces, thereby forming a negative pressure in the control spaces, which is beneficial for the solvent to pass through the control spaces and be extracted by the exhaust fans.

2. The electrospinning collection device according to claim 1, characterized in that: The collecting conveyor belt comprises a collecting mesh belt, two rolling shafts and a motor. The collecting mesh belt is evenly and densely covered with through holes. The collecting mesh belt is wound around two rolling shafts parallel to each other. The rolling shafts are connected to the motor to drive the rolling shafts to rotate, thereby driving the collecting mesh belt to move. A plurality of first tracks are evenly arranged on the inner side of the collecting mesh belt for connecting the heat transfer unit to realize contact heat transfer; the first tracks are recessed toward the outer side of the collecting mesh belt, and the first tracks are parallel to each other and perpendicular to the rolling axis.

3. The electrospinning collection device according to claim 2, characterized in that: The collecting mesh belt is made of stainless steel, and the through holes on the collecting mesh belt are arranged in an orderly manner horizontally and vertically, forming a matrix distribution; The rolling shaft is a tension shaft, the tension shaft is a polymer insulating material, and the two tension shafts are used to stretch the collecting mesh belt so that the lower mesh belt can remain horizontal, thereby ensuring uniform collection of the nanofibers.

4. The electrospinning collection device according to claim 2, characterized in that: The heating unit includes a plurality of heating coils, connecting pipes and a heating device. The heating coils are distributed in a serpentine shape and are evenly coiled inside the heat transfer chamber. The two ends of the heating coils are respectively close to the two rolling shafts. The two ends of the heating coils are respectively connected to the inlet and outlet of the heating device through the connecting pipes. Several heating coils are stacked up and down to increase the heat supply; the heating coils are filled with heat-conducting silicone oil, and the heating device can heat the silicone oil and drive the silicone oil to circulate in the heating coils.

5. The electrospinning collection device according to claim 2, characterized in that: The isolation soft plate includes a plurality of isolation plates that cross each other horizontally and vertically. The isolation plates are all arranged vertically. The tops of the isolation plates are connected to the lower surface of the heat transfer chamber. The horizontal isolation plates are parallel to the first track, and the vertical isolation plates are perpendicular to the first track. A plurality of horizontally and vertically intersecting isolation plates are evenly arranged below the heat transfer chamber in a matrix arrangement, and the space between the bottom surface of the heat transfer chamber and the lower mesh belt is evenly divided into a plurality of control spaces of the same size.

6. The electrospinning collection device according to claim 5, characterized in that: The heat transfer unit comprises a heat transfer chamber, a heat transfer component and a heat transfer rod group. The heat transfer chamber is filled with silicone oil. The heat transfer component is arranged on the lower surface of the heat transfer chamber. The heat transfer component comprises a plurality of heat transfer bars parallel to each other. The heat transfer bars are solid metal bars. A second track is arranged on the lower surface of the heat transfer bars. The second track is parallel to the first track and corresponds to the first track up and down. The heat transfer rod group includes a plurality of rows of heat transfer rods, each row of heat transfer rods corresponds to a second track, the top ends of the heat transfer rods are connected to the second track, and the bottom ends of the heat transfer rods are connected to the first track.

7. The electrospinning collection device according to claim 6, characterized in that: The heat transfer strip is a rectangular parallelepiped and is parallel to the first track. The heat transfer strip runs through all longitudinal isolation plates. The second track is concave upward and is located in the center of the heat transfer strip.

8. The electrospinning collection device according to claim 6, characterized in that: The heat transfer chamber is in the shape of a flat rectangular parallelepiped and is a horizontally arranged closed chamber. The four sides of the heat transfer chamber are respectively close to the two rolling shafts and the two sides of the collecting mesh belt, so that the collecting mesh belt can fully transfer heat. The heat transfer chamber is provided with brackets on the two sides corresponding to the two sides of the collecting mesh belt, and the bottom of the brackets is connected to the support frame or the ground to support the heat transfer chamber. A liquid level measuring device and a silicone oil expansion buffer are provided in the heat transfer chamber to detect the filling condition of the silicone oil in the heat transfer chamber and prevent the components from being compressed due to the thermal expansion of the silicone oil.

9. The electrospinning collection device according to claim 8, characterized in that: A plurality of vertical air ducts are preset inside the heat transfer chamber, and the upper and lower ends of the vertical air ducts are respectively connected to the top surface and the bottom surface of the heat transfer chamber, and the upper and lower ends of the vertical air ducts are open and connected to the external space of the heat transfer chamber; The bottom end of the vertical air duct is an exhaust outlet and corresponds to the central position of a control space. The inlet of the exhaust duct is connected to the top of the vertical air duct through the outlet base, and the outlet of the exhaust duct is connected to the exhaust fan. The exhaust duct is parallel to the rolling axis, and the exhaust fan is arranged on the outer side of the collecting mesh belt, which does not affect the movement of the collecting mesh belt and does not occupy the space inside the collecting mesh belt.

10. The electrospinning collection device according to claim 8, characterized in that: A row of heat transfer rods includes a plurality of heat transfer rods arranged in a row. The top and bottom ends of the heat transfer rods are respectively provided with spherical outwardly protruding clamping parts, which are respectively used to clamp into the second track and the first track, so that the heat transfer bar transfers heat to the lower mesh belt through the heat transfer rods, realizing contact heat transfer and improving heat transfer efficiency. The heat transfer bar and the heat transfer rod are both made of metal.

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