CN106435772A - Method and device for preparing nano fiber by using electrostatic method - Google Patents

Abstract

The invention relates to a method and a device for preparing nanofibers by an electrostatic method, and belongs to the field of electrostatic spinning. A method for preparing nanofibers by an electrostatic method, characterized in that: through the arrangement of the receiver and the cooperation between the receiver and the wire outlet device, a high-voltage electrostatic field with a specific intensity or distribution is formed between the wire outlet device and the receiver, and the high-voltage Under the action of the electrostatic field, the charged droplets form Taylor cones and produce a whipping effect, and then form specific nanofibers or nanofibers in a specific arrangement. The method and device of the present invention propose to affect the high-voltage electric field by changing the collector or receiver, so that the high-voltage electric field has different distribution intensities, thereby forming nanofibers and nanofiber aggregates with different distributions or forms, so that specific requirements or special requirements can be prepared. Aligned nanofibers and nanofiber aggregates with specific structures.

Description

A method and device for preparing nanofibers by electrostatic method

technical field

The invention relates to an electrospinning method and a device, in particular to a method and a device for preparing nanofibers and nanofiber aggregates by an electrostatic method.

Background technique

As a nanofiber manufacturing technology, electrospinning mainly uses high-voltage electric field to make the droplet become cone-shaped to form a Taylor cone, and then extend under the action of electrostatic force to form nano-scale ultrafine fibers. Electrospinning has become a research hotspot in the preparation of nanofiber materials due to its advantages such as a wide variety of spinnable materials and good process controllability.

Based on the current research on electrospinning, it is believed that the essence of electrospinning is to rapidly generate jet flow. Therefore, a series of researches on electrospinning are mainly focused on the influence of the structure of the spinneret hole on the fiber formation, which is specifically reflected in Research on injection needles for solutions or melts, such as various shapes or types of injection needles, or needle-free injection cylinders or injection devices.

Or research on the industrialization of electrospinning technology, such as the collection method for the produced nano-scale ultrafine fibers. For example, in the U.S. Patent US6106913A, the ultrafine fiber is guided to the filament by the air deposition method, and the high-strength nanofiber core-spun yarn is formed by traction and winding; or the dynamically rotating horn-shaped collector used in the Chinese patent CN201410280734.X , a collection method that guides microfibers onto filaments and twists them.

In these researches on the production method and collection and utilization method of nano-ultrafine fibers based on electrospinning, the former mainly studies the use of different spinnerets or nozzles to produce fluids of different shapes, all of which are collecting plates or receiving plates. Collect the generated fibers; although the latter improves the collector or receiver, the collector is not used as a component of the high-voltage electric field, but only as a collection device for the ultra-fine fibers generated in the high-voltage electric field. collect.

Contents of the invention

The present invention proposes a method and device for preparing nanofibers by electrostatic method. By changing the collector or receiver to affect the high-voltage electric field, the high-voltage electric field has different distribution intensities, thereby forming nanofibers with different distributions or forms.

Technical solutions

A method for preparing nanofibers by an electrostatic method, characterized in that: through the arrangement of the receiver and the cooperation between the receiver and the wire outlet device, a high-voltage electrostatic field with a specific intensity or distribution is formed between the wire outlet device and the receiver, and the high-voltage Under the action of the electrostatic field, the charged droplets form Taylor cones and produce a whipping effect, and then form specific nanofibers or nanofibers in a specific arrangement.

The intensity of the high-voltage electrostatic field is adjusted by adjusting the distance between the receiver and the wire output device to form a high-voltage electrostatic field with a specific intensity.

By adjusting the shape of the receiver so as to adjust the distribution of the high-voltage electrostatic field, a specific distribution of high-voltage electrostatic field is formed between the wire output device and the receiver.

The wire output device is connected to the positive pole of the static generator, and the receiver is connected to the negative pole of the static generator or grounded.

The cross section of the wire outlet hole of the wire outlet device is concentric or eccentric.

A device for preparing nanofibers using the electrostatic method of the above-mentioned method, including a silk output device and a receiver, characterized in that: the silk output device is connected to the positive pole of the electrostatic generator, and the receiver is connected to the negative pole of the electrostatic generator or Grounding, forming a high-voltage electrostatic field between the wire output device and the receiver, the receiver is connected to the negative pole or neutral line of the electrostatic generator through a coaxial connection assembly, and a joint is provided at one end of the receiver, and the coaxial connection assembly is connected to the neutral wire of the electrostatic generator. The joints are connected coaxially.

The coaxial connection assembly includes a transmission shaft coaxially connected with the joint of the receiver, the transmission shaft is covered with a coaxial hollow shaft, the hollow shaft is arranged on the fixed bearing frame through the bearing, and the gap between the hollow shaft and the transmission shaft Fixed by adjusting screw.

There is a through hole on the side wall of the hollow shaft, and an adjusting screw is set in the hole. By loosening the adjusting screw, the relative position of the transmission shaft and the hollow shaft is adjusted. After fixing the adjusting screw, the transmission shaft and the hollow shaft are fixed to realize the position of the receiver. front and rear adjustment.

The receiver adopts a receiver with a certain distribution surface shape, including a tray receiver or a ring receiver, or a wheel receiver, or a disc mesh receiver, or a mesh horn receiver.

The receiver adopts a point or line receiver, including a needle plate receiver or a tapered metal helical wire receiver.

The filament outlet device adopts a point-shaped filament outlet device, including a single spinneret or multiple spinnerets.

The silk-out device is a double spinneret arranged on the spinneret rack, and the double spinneret is arranged symmetrically, and the bottoms of the two spinneret racks are vertically fixed on one end of the long connecting rod, and the other end of the long connecting rod It is fixed by a positioning pin, and a short connecting rod is connected to the middle of the long connecting rod. One end of the pull rod, the pull rod is fixed on the guide seat, pull the pull rod, the pull rod pushes the long connecting rod to rotate around the fixed end of the long connecting rod through the short connecting rod, and drives the spinnerets on the two spinneret holders away from or close to the receiver .

The wire outlet device adopts a wire outlet device with a certain distribution surface shape, including a spinneret with a plurality of concentrated spinneret holes.

The filament output device is arranged at the front end of the spinneret arm, and the spinneret arm is driven by a reciprocating device to realize reciprocating motion along the receiving surface of the receiver.

The reciprocating device includes a slide rail and a slide plate, the spinneret arm is installed on the slide plate, and the drive motor is installed on both sides of the slide rail to drive the timing belt parallel to the slide rail and arranged above the slide rail, thereby driving the timing belt arranged on the slide rail The slide plate on the slide slides on the slide rail, and the slide plate drives the spinneret arm to reciprocate on the slide rail.

The spinneret arm adopts multi-section arms, and the wire outlet device and the front end of the spinneret arm and the arms of each section of the spinneret arm are connected by pins to realize mutual rotation, and the rear end of the spinneret arm is also pinned. The shaft is connected to the reciprocating device, which can make the wire output device stay at the set position and adjust the distance between the wire output device and the receiver.

Beneficial effect

The method and device for preparing nanofibers by the electrostatic method provided by the present invention change the intensity or distribution of the high-voltage electric field through the setting of the receiver, thereby controlling the charged droplets to form Taylor cones in the high-voltage electric field, and the subsequent trajectory in the high-voltage electric field to form Nanofibers with specific requirements or nanofibers with specific arrangements;

The device for preparing nanofibers of the present invention connects the receiver and the negative electrode of the high-voltage electrostatic generator through a coaxial connection assembly, so that the device can be replaced with different receivers, so that the receiver can be replaced according to the structure and type of nanofibers required, and the efficiency of the device can be improved. Versatility and adaptability.

Description of drawings

Fig. 1 is the schematic diagram of the electrostatic field that point-to-face distribution is formed between the silk outlet device and the receiver of the present invention;

Fig. 2 is the schematic diagram that the electrostatic field of point-to-point distribution is formed by the silk outlet device of the present invention and the receiver;

Fig. 3 is the schematic diagram of the electrostatic field of face-to-point distribution formed by the silk output device and the receiver of the present invention;

Fig. 4 is the schematic diagram of the electrostatic field distributed face-to-face between the silk output device and the receiver of the present invention;

Fig. 5 is a schematic diagram of continuously preparing nanofiber aggregates by drawing filaments in the present invention;

Fig. 6 is a schematic diagram of the device of the present invention, wherein the silk-discharging device adopts a point-shaped silk-discharging device;

Fig. 7 is a schematic diagram of the receiver installed on the coaxial connection assembly;

Fig. 8 is a schematic view of the structure of the spinneret frame;

Fig. 9 is a schematic diagram of the reciprocating motion device when the silk outlet device is a spinneret;

Figure 10 is a schematic bottom view of Figure 9;

Figure 11 is a schematic side view of the spinneret arm;

Fig. 12 is a schematic diagram of the arrangement of the wire outlet device and the receiver in the box when the wire outlet device is a spinneret;

Fig. 13 is a schematic diagram of a tray receiver;

Fig. 14 is a schematic diagram of a needle plate receiver;

Figure 15 is a schematic diagram of a tapered metal helix receiver.

Among them: 1-enclosed box, 2-control electric cabinet, 3-receiver connector, 4-safety switch, 5-heating and exhaust device, 6-liquid storage device, 7-fixed bearing frame, 8-spinneret Frame, 9-nanofiber, 10-electrostatic generator, 11-magnetic eye, 12-baffle base, 13-drawing filament, 14-wire frame, 15-winding device, 16-filament output device, 17-receiving Device, 18-reciprocating device, 19-rotating motor, 20-preprocessing device, 21-adjusting screw, 22-hollow shaft, 23-transmission shaft, 24-bearing, 25-receiver bottom plate, 26-receiver front end, 181-drive motor, 182-spinneret arm, 183-pin shaft, 184-synchronous belt, 185-slide rail, 186-slider, 187-proximity switch, 81-spinneret frame, 82-long connecting rod, 83 -short connecting rod, 84-pull rod, 85-return spring, 86-guiding seat, 87-through-hole star handle.

detailed description

The present invention will be further described below in combination with specific embodiments and accompanying drawings.

Based on the electrohydraulic motion model of Taylor cone proposed by Taylor, the extensive research on electrospinning is now focused on the research on the solution or melt injection device or the research on the fiber collection device, but for the preparation of different characteristics or different The structural requirements for nanofibrous aggregates are still largely unknown.

The present invention proposes to make the high-voltage electric field meet specific requirements in intensity and distribution by changing the receiver as part of the electrostatic field, so that the critical charge density, Taylor The cone becomes unstable, forming a jet jet, and the jet is accelerated in the electric field, the diameter becomes smaller, and the series of movements of the microfiber is relaxed, affecting the charged droplet, forming a specific form of nano-ultrafine fiber, and receiving As a collection device, the nano ultrafine fibers are collected according to a certain arrangement and requirements, forming nanofibers with a specific distribution and a nanofiber aggregate with a specific structure.

When the receiver and the wire outlet device are respectively connected to the negative and positive poles of the high-voltage electrostatic generator, a high-voltage electrostatic field is formed between the receiver and the wire outlet device, and the solution or melt in the liquid storage device connected to the wire outlet device is in the When passing through the capillary in front of the spinneret of the spinning device, the droplet has been charged and is subjected to electrostatic force in the electrostatic field formed by the receiver and the spinning device.

When the wire outlet device adopts a point-shaped wire outlet device and the receiver adopts a shape with a certain distribution surface, an electrostatic field distributed point-to-face is formed between the wire outlet device and the receiver, as shown in Figure 1, 16 is the wire outlet The device, 17, is a receiver, and the jet ejected from the filament output device will form a cone-like jet area shown by the dotted line in the figure in this electrostatic field, which will affect the shape and distribution of nanofibers.

And when the wire outlet device adopts a point-shaped wire outlet device, and the receiver adopts a point-shaped or linear receiver, an electrostatic field distributed point-to-point is formed between the wire outlet device and the receiver, as shown in Figure 2, the wire outlet device In this electrostatic field, the ejected jet will form a spindle-shaped jet region as indicated by the dotted line in the figure.

When the wire outlet device adopts a shape with a certain distribution surface, and the receiver adopts a point-shaped or linear receiver, an electrostatic field distributed in a point-to-point manner is formed between the wire outlet device and the receiver, as shown in Figure 3. In this electrostatic field, the jet stream ejected from the wire device will form an inverted cone-shaped jet area as indicated by the dotted line in the figure.

When the wire outlet device adopts a shape with a certain distribution surface, and the receiver also adopts a shape with a certain distribution surface, an electrostatic field distributed face-to-face is formed between the wire outlet device and the receiver, as shown in Figure 3, the wire outlet device In this electrostatic field, the ejected jet forms a cylindrical jet region as indicated by the dotted line in the figure.

There are many kinds of filament discharge devices distributed in a point shape or in a certain plane. Therefore, by changing the cooperation between different receivers and filament discharge devices to form different electrostatic fields, different jet regions can be formed to affect the shape of nanofibers. and distribution to obtain nanofibers with specific requirements or nanofibers with specific distributions.

At the same time, the intensity of the high-voltage electrostatic field can be adjusted by adjusting the distance between the receiver and the filament output device to form a high-voltage electrostatic field with a specific strength to assist in the formation of different nanofibers.

The outlet hole of the wire outlet device can adopt single hole or multi-layer composite hole to form a single fiber or composite fiber. The cross section of the outlet hole can be concentric or eccentric, so that when the charged droplet forms a Taylor cone Controlling the shape of the nanofibers.

Make the receiver and the silk outlet device move relatively, so that more and better nanofibers are formed or deposit on the receiver that moves relatively with the silk outlet device in a certain sequence to form the required nanofiber assembly. During collection, the collection can be assisted by rotating the receiver about the central axis.

It is also possible to set a drawing filament on the central axis of the receiver, and cooperate with the receiver rotating with the central axis as the rotation axis to receive nanofibers. A nanofiber assembly is formed on the surface of the drawing filament, and one end of the drawing filament is connected to a winding device to realize continuous preparation of the nanofiber assembly. As shown in accompanying drawing 5, among the figure 13 is drawing filament.

Or reciprocate the output device along the receiving surface of the receiver to form a sheet-like nanofiber aggregate on the receiving surface of the receiver. fiber aggregates.

Based on the above method for preparing nanofibers and nanofiber aggregates, a device as shown in Figure 6 can be used. Set the wire outlet device and the receiver inside the closed box, the wire outlet device is connected to the positive pole of the electrostatic generator, the receiver is connected to the negative pole of the electrostatic generator or grounded, and a high-voltage electrostatic field is formed between the wire outlet device and the receiver. The receiver is connected to the negative pole or neutral line of the electrostatic generator through a coaxial connection assembly, and a joint is provided at one end of the receiver, and the coaxial connection assembly is connected to the joint coaxially, and the coaxial connection assembly is connected to the output shaft of the rotating motor .

The coaxial connection assembly includes a transmission shaft coaxially connected with the joint of the receiver, the transmission shaft is covered with a coaxial hollow shaft, the hollow shaft is arranged on the fixed bearing frame through the bearing, and the gap between the hollow shaft and the transmission shaft Fixed by adjusting screw. There is a through hole on the side wall of the hollow shaft, and an adjusting screw is set in the hole. By loosening the adjusting screw, the relative position of the transmission shaft and the hollow shaft is adjusted. After fixing the adjusting screw, the transmission shaft and the hollow shaft are fixed to realize the position of the receiver. front and rear adjustment. As shown in Figure 7.

A traction filament is arranged on the central axis of the receiver, and the center of the receiver and the coaxial connection assembly is provided with a communicating hole for the traction filament to pass through. The traction filament is driven by the winding device and passes through the The electrostatic field area between the receiver and the filament discharge device continuously collects the nanofiber aggregates formed on the surface of the drawn filaments. As shown in accompanying drawing 6, among the figure 13 is drawing filament, and 14 is wire frame, and 15 is winding device.

The receiver can be in a shape with a certain receiving surface, such as a tray receiver or a ring receiver, or a wheel receiver, or a disc mesh receiver, or a mesh horn receiver. A variety of receptors can make the nanofibers more orderly and tightly combined. The wheel-type receiver, the mesh-type horn receiver and the disc-mesh receiver mainly rely on the airflow holes on both sides of the receiver, which can form a swirling airflow to restrain the divergence of the jet and arrange the nanofibers in an orderly manner. Figure 13 is a schematic diagram of a tray receiver.

The receiver can also be a point or line receiver, such as a needle plate receiver or a tapered metal helical wire receiver. When the receiver of needle lattice is used, the nanofiber can be divided into several strands, which avoids the disorder of the nanofiber, but is attached to different receiving needles respectively to achieve an orderly arrangement; while using a tapered helical wire receiver , the concentration of charges on the helical metal wire will make the nanofibers received at the top of the tapered metal helix more dense, and the density of the deposited nanofibers will be higher, while the density of the nanofibers will gradually decrease to achieve a specific structure of nanofibers. For example, accompanying drawing 14 is a schematic diagram of a needle plate receiver, and accompanying drawing 15 is a schematic diagram of a conical metal helical wire receiver. These two receivers all include a non-metallic receiver base plate and a metal receiver front end, and the receiver front ends are respectively Needle plate type and tapered metal spiral type, the front end of the needle plate type is a linear receiver composed of points.

And the wire outlet device can also adopt a point-shaped wire outlet device, including a single spinneret or multiple spinnerets. The silk-out device adopted in this embodiment is a double spinneret arranged on the spinneret frame, and the double spinneret is symmetrically arranged, and the bottoms of the two spinneret frames are all vertically fixed on one end of the long connecting rod, and the length The other end of the connecting rod is fixed with a positioning pin, and a short connecting rod is connected in the middle of the long connecting rod. It is fixed at one end of the pull rod, and the pull rod is fixed on the guide seat. When the pull rod is pulled, the pull rod pushes the long connecting rod to rotate around the fixed end of the long connecting rod through the short connecting rod, driving the spinnerets on the two spinneret holders away from the or close to the receiver. As shown in Figure 8.

Alternatively, the wire outlet device may be a wire outlet device with a certain distribution surface shape, such as a spinneret with a plurality of concentrated spinneret holes. The spinning device is arranged at the front end of the spinneret arm, and the spinneret arm is driven by a reciprocating device to realize reciprocating motion along the receiving surface of the receiver.

The reciprocating device includes a slide rail and a slide plate, the spinneret arm is installed on the slide plate, and the drive motor is installed on both sides of the slide rail to drive the timing belt parallel to the slide rail and arranged above the slide rail, thereby driving the timing belt arranged on the slide rail The slide plate on the slide slides on the slide rail, and the slide plate drives the spinneret arm to reciprocate on the slide rail. Proximity switches with adjustable positions are respectively arranged at both ends of the slide rail, which are used to detect the position of the edge during the motion of the slide plate and limit the moving range of the reciprocating motion of the spinneret arm. The spinneret arm can adopt multi-section arms, and the wire output device and the front end of the spinneret arm and each section of the spinneret arm are connected by pin shafts to realize mutual rotation. The rear end of the spinneret arm is also connected with The pin shaft is connected to the reciprocating device, which can make the wire output device stay at the set position and adjust the distance between the wire output device and the receiver. The structure of the reciprocating device is shown in Figures 9 to 11. Figure 10 is a schematic bottom view of Figure 9, and Figure 11 is a schematic view of the spinneret arm viewed from the side. Accompanying drawing 12 is the schematic diagram of the installation of the spinning device and the cylindrical receiver of the spinneret in the closed box.

The closed box body is mainly an electrostatic field area, and a temperature and humidity sensor and a heating exhaust device are also arranged in the box body to adjust the temperature, humidity and exhaust air inside the box body. As shown in Figure 6, a heating and exhaust device is provided on the top of the box, and a plurality of evenly distributed heating modules are used to uniformly heat the box, and the edge of each heating module is provided with an exhaust hole. The closed box body can not only reduce the influence of the environment on electrospinning, but also improve the safety. There is a box door on the side of the box body, and a safety switch is set at the place where the box door contacts the box body for control. The electrostatic generator stops working when the cabinet door is opened. The safety switch is inlaid in the place where the edge of the box body contacts with the box door, and is connected with the high-voltage electrostatic generator. If the box door is opened when the high-voltage electrostatic generator is turned on, the high-voltage electrostatic generator can automatically cut off the power, so as to ensure the safety during operation. security.

The side wall of the box body is also provided with a liquid storage device, and the liquid storage device includes a plurality of independent liquid storage tanks, and each liquid storage tank is respectively connected to different spinnerets of the silk output device. The liquid storage device can be mechanically driven or pneumatically driven to discharge liquid.

There is a control electric cabinet at the bottom of the box, and a rotating motor on the side of the box. The control electric cabinet is connected to an external power supply. An electrostatic generator and a controller are installed inside the control electric cabinet. Cable crawlers are installed on the inner side of the control electric cabinet to bundle the connecting wires. Into the cable crawler, lead out from the rear side of the top plate of the control electric cabinet, and connect to the device inside the box and the device on the side of the box respectively.

When the device shown in accompanying drawing 6 is in operation, after the traction filament is pushed out by the wire rack, it enters the inside of the casing through the transmission shaft with a through hole, and the other end of the transmission shaft through hole is connected to the through hole in the center of the receiver, so that the traction The filament passes through the through hole of the receiver and enters the electrospinning area between the receiver and the spinneret of the filament outlet device, and then is led out by the magnetic eye on the opposite side wall of the box, and is drawn by the outer side of the box. Winding device collection. During the electrospinning process, the propulsion system and the high-voltage electrostatic generator on the outside of the box are turned on, so that the spinneret ejects the solution, and forms nanofibers under the action of an electrostatic field, and the formed nanofibers are deposited on the drawn filaments to form nanofibers. fiber aggregates. A coaxial hollow shaft is set outside the transmission shaft connected to the receiver, the hollow shaft is fixed on the fixed bearing frame, and the other end of the transmission shaft protrudes from the casing, and a driven wheel is provided to connect with the rotating motor. Driven by the rotating motor, the rotating receiver drives the deposited nanofibers to rotate continuously, and then the formed nanofiber assembly is exported by pulling the filaments, and wound onto the winding device outside the box.

When the device shown in accompanying drawing 12 is in operation, the cylindrical receiver rotates, and the wire output device using the spinneret reciprocates relative to the receiving surface of the receiver under the drive of the reciprocating motion device, forming a thin sheet type on the receiving surface of the receiver. For the nanofiber assembly, the receiver rotates along the rotation axis parallel to the moving direction of the silk outlet device to form a continuous sheet-type nanofiber assembly, which can be continuously prepared after being exported to the outside of the box.

Claims (16)

1. A method for preparing nanofibers by an electrostatic method, characterized in that: through the arrangement of the receiver and the cooperation of the receiver and the silk output device, a high-voltage electrostatic field of specific intensity or distribution is formed between the silk output device and the receiver, Under the action of a high-voltage electrostatic field, the charged droplets form Taylor cones and produce a whipping effect, thereby forming specific nanofibers or nanofibers in a specific arrangement. 2. The method for preparing nanofibers by electrostatic method as claimed in claim 1, characterized in that: the intensity of the high-voltage electrostatic field is regulated by adjusting the distance between the receiver and the silk output device to form a high-voltage electrostatic field of specific intensity. 3. The method for preparing nanofibers by electrostatic method as claimed in claim 1, characterized in that: the distribution of the high-voltage electrostatic field is adjusted by adjusting the shape of the receiver, and a specific distribution of high-voltage static electricity is formed between the silk output device and the receiver. field. 4. The method for preparing nanofibers by electrostatic method according to claim 1, 2 or 3, characterized in that: the filament output device is connected to the positive pole of the static electricity generator, and the receiver is connected to the negative pole of the static electricity generator or grounded. 5 . The method for preparing nanofibers by electrostatic method according to claim 1 , 2 or 3 , characterized in that: the cross-section of the outlet hole of the outlet device is concentric or eccentric. 6 . 6. A device for preparing nanofibers using the electrostatic method of the method as claimed in claim 1, comprising a silk outlet device and a receiver, characterized in that: the silk outlet device is connected to the positive pole of the electrostatic generator, and the receiver Connect the negative pole or ground of the electrostatic generator to form a high-voltage electrostatic field between the wire outlet device and the receiver. The receiver is connected to the negative pole or neutral line of the electrostatic generator through a coaxial connection assembly. A connector is provided at one end of the receiver. The coaxial connection component is coaxially connected with the joint. 7. The device for preparing nanofibers by electrostatic method as claimed in claim 6, characterized in that: the coaxial connection assembly includes a transmission shaft connected coaxially with the joint of the receiver, and the transmission shaft is covered with a coaxial hollow shaft , the hollow shaft is arranged on the fixed bearing frame through bearings, and the hollow shaft and the drive shaft are fixed by adjusting screws. 8. The device for preparing nanofibers by electrostatic method according to claim 7, characterized in that: the side wall of the hollow shaft has a through hole, and an adjusting screw is arranged in the hole, and the distance between the transmission shaft and the hollow shaft is adjusted by loosening the adjusting screw. Relative position, after fixing the adjusting screw, fix the transmission shaft and the hollow shaft to realize the front and rear adjustment of the receiver position. 9. The device for preparing nanofibers by electrostatic method as claimed in claim 6, characterized in that: the receiver adopts a receiver with a certain distribution surface shape, including a tray receiver or a ring receiver, or a wheel disc type receiver, or disc mesh type receiver, or mesh type horn receiver. 10. The device for preparing nanofibers by electrostatic method according to claim 6, characterized in that: the receiver is a point or line receiver, including a needle plate receiver or a tapered metal helix receiver. 11 . The device for preparing nanofibers by electrostatic method according to claim 6 , characterized in that: the filament outlet device is a point-shaped filament outlet device, including a single spinneret or multiple spinnerets. 12. The device for preparing nanofibers by electrostatic method as claimed in claim 11, characterized in that: said silk output device is a double spinneret arranged on a spinneret frame, and said double spinnerets are arranged symmetrically, and the two spinnerets are arranged symmetrically. The bottoms of each spinneret frame are vertically fixed on one end of the long connecting rod, the other end of the long connecting rod is fixed by a positioning pin, and a short connecting rod is connected in the middle of the long connecting rod, and one end of the short connecting rod is fixed on the long connecting rod by a pin. On the rod, the other end of the short connecting rod is connected to a pull rod, and is fixed to one end of the pull rod through a pin shaft. The fixed end rotates to drive the spinnerets on the two spinneret holders away from or close to the receiver. 13. The device for preparing nanofibers by electrostatic method as claimed in claim 6, characterized in that: said silk-discharging device adopts a silk-discharging device with a certain shape of distribution surface, including a spinneret having a plurality of concentrated spinneret holes. plate. 14. The device for preparing nanofibers by electrostatic method as claimed in claim 11 or 13, characterized in that: the filament output device is arranged at the front end of the spinneret arm, and the spinneret arm is driven by a reciprocating device to realize reciprocating motion of the receiving surface. 15. The device for preparing nanofibers by electrostatic method according to claim 14, characterized in that: the reciprocating device comprises a slide rail and a slide plate, the spinneret arm is mounted on the slide plate, and the driving motor is installed on both sides of the slide rail, The timing belt parallel to the slide rail and arranged above the slide rail is driven, thereby driving the slide plate arranged on the slide rail to slide on the slide rail, and the slide plate drives the spinneret arm to reciprocate on the slide rail. 16. The device for preparing nanofibers by electrostatic method as claimed in claim 14, characterized in that: the spinneret arm adopts multi-section arms, and the wire outlet device and the front end of the spinneret arm and each section of the spinneret arm Both are connected by pin shafts to realize mutual rotation, and the rear end of the spinneret arm is also connected to the reciprocating device by pin shafts, which can make the wire outlet device stay at the set position and adjust the distance between the wire outlet device and the receiver. distance.