Method for producing linear nanofiber structures from polymer solution or polymer melt in alternating current (AC) electric field and apparatus for carrying out method

Abstract

The invention relates to a method for producing linear nanofiber structures from a polymer solution or a polymer melt in an AC electric field, in which nanofibers (5) are formed from a polymer solution (21) or a polymer melt in a spinning region (110, 120, 130) formed on a spinning electrode (1, 11, 12, 13), and is conveyed away from the spinning region by the action of the electric wind in the direction of the gradient of the generated electric field. A polymer solution (21) or a polymer melt is conveyed to a spinning zone (110, 120, 130) by moving a spinning electrode (1, 11, 12, 13) and subjected to an electric field of supercritical intensity (E) to form nanofibers (5), moved away from the spinning zone (110, 120, 130) and deposited on a collection zone (40, 410, 420) of a moving electrically neutral collector (4, 41, 42) on which they form a fluffy ribbon (51) of nanofibers, which passes through the electrically neutral collector (4, 41, 42) and is deposited on the collection zone (40, 410, 420). The electrically neutral collector (4, 41, 42) is moved to a pull-out region (401, 410, 420) as a result of the movement of the electrically neutral collector (4, 41, 42), in which the surface of the electrically neutral collector (4, 41, 42) is pulled out by the pulling force of the winding device (7) or extraction device and then wound. Twisting the fluffy ribbon (51) of nanofibers into a nanofiber yarn (54) after it is pulled out of the electrically neutral collector (4, 41, 42) may be done before and after winding. The invention further relates to a device for carrying out the method.

Description

Technical Field

[0001] The present invention relates to a method for producing a linear nanofiber structure from a polymer solution or melt in an AC electric field, wherein a spinning zone with a supercritical AC electric field strength is formed on a spinning electrode. In the spinning zone, nanofibers are formed, which are carried away from the spinning electrode by the action of an electric wind in the direction of the maximum value of the gradient of the generated electric field.

[0002] The present invention also relates to an apparatus for producing a linear nanofiber structure from a polymer solution or melt in an AC electric field, wherein a spinning zone with a supercritical value of the AC electric field strength is generated on a spinning electrode, which is installed in a spinning chamber and connected to a high AC voltage source and is connected to a device for applying a polymer solution or melt to the surface of the spinning electrode. Background Art

[0003] In the preparation of nanofiber yarns, oriented nanofibers are the basis of the construction of nanofiber yarns. At present, many methods have been developed in the field of DC electrospinning to obtain longitudinally oriented fiber bundles, which can be attributed to two main aspects, namely, obtaining highly ordered nanofibers by improving the collection equipment or by affecting the electric field with the help of auxiliary electrodes.

[0004] CN111118677 discloses the production of nanofiber yarn by DC electrostatic spinning. The device includes a cylindrical collector, which consists of a cavity and a throat that can rotate around its axis, wherein the diameter of the upper opening of the throat is smaller than the diameter of the lower opening of the cavity. A DC electrostatic rotating spinning electrode is installed inside the lower opening of the cavity, and the spinning electrode is connected to a high-voltage DC source, and the solution to be electrostatically spun is fed into the high-voltage DC source. In the upper part of the collector cavity, a pressurized air inlet leads to the internal space of the collector, and a counter electrode is arranged above it, which can be grounded or connected to a voltage source of opposite polarity to the rotating spinning electrode.

[0005] The nanofibers formed on the rotating spinning electrode are transported to the counter electrode by the action of the electrostatic field, and by the action of the air flow, they are transported upward into the throat of the rotating cylindrical collector, and due to its rotation and the supplied air flow, vortices are generated, which twist the nanofibers into yarns, which are subsequently pulled out and wound on a bobbin.

[0006] Due to the rotation of the spinning electrodes and the subsequent effect of eddy currents, the nanofibers are twisted immediately after their formation, so that there is no parallelization of the nanofibers before twisting, the twisting occurs unevenly, and therefore their strength and appearance are variable.

[0007] CN111286792 describes a horizontal arrangement of a DC electrostatic spinning device, which includes a rotating jet spinning electrode and a collecting electrode formed by a hollow cylinder, which is coaxially arranged relative to the jet spinning electrode, wherein a DC electric field is formed between the spinning electrode and the collecting electrode. At least two air jets pointing to the axis of the collecting electrode are arranged around the rotating jet spinning electrode. Due to the electric wind, the nanofibers formed by the rotating jet spinning electrode are transported to the hollow cylinder forming the collecting electrode, wherein due to the rotation of the jet spinning electrode and the air flow from the jet, the nanofibers are twisted into yarns, which are drawn out and wound on a bobbin after passing through the cavity of the collecting electrode.

[0008] In this solution, the goal is also to twist the nanofibers as quickly as possible after their formation without achieving their parallelization.

[0009] In both cases, disadvantages of DC electrospinning production of nanofiber yarns include low yarn cohesion, irregular twist and poor orientation of the nanofibers.

[0010] At present, a method for continuously preparing nanofiber yarn is also known, for example from CN110644080, in which nanofibers are formed from a polymer solution in a jet head, the nanofibers are drawn out of the jet head by the action of a high-speed airflow generated in a venturi tube, and enter a venturi collection system through a funnel-shaped collection tube, where they are straightened and oriented into oriented nanofiber bundles by sucking the nanofiber bundles using the Venturi effect. The oriented nanofiber bundles are then twisted and gathered into nanofiber yarns by the action of a twisting device, which is wound on a bobbin in the next step. The twisting device includes an air nozzle for supplying an air flow in a tangential direction toward the yarn to be twisted.

[0011] From the perspective of the subsequent processing and use of nanofiber yarns, in order to meet the current requirements for their preparation, it is not enough to simply obtain oriented fibers, but it is also necessary to be able to continuously obtain oriented fibers or fiber bundles and to be able to evenly apply a certain degree of twist to them to ensure their length and degree of orientation. In order to optimize the strength of the nanofiber yarn, it is advantageous if the nanofibers in the nanofiber bundle are already longitudinally oriented due to the method of their formation, that is, they are oriented in line with the axis of the bundle. Existing DC electrospinning technologies for the continuous production of nanofiber yarns have low yields and poor quality of the nanofiber yarns produced. Therefore, core yarns are currently produced by DC electrospinning.

[0012] For example, CZ PV 2007-179 discloses a linear fiber structure comprising polymer nanofibers, which form a coating on the surface of a core formed by a supporting linear fiber structure, and at least some of the nanofibers are captured between the fibers of the surface portion of the core. The nanofibers are produced by DC electrostatic spinning (i.e., using a high voltage DC source), wherein the supporting linear structure is guided through the spinning space between the spinning electrode and the collecting electrode, and outside the spinning space, the nanofibers are subjected to false twisting. Therefore, the supporting linear structure in the spinning space rotates around its axis, and the individual nanofibers transported to the collecting electrode by the spinning space are deposited on its surface. Not all nanofibers are captured on the supporting linear structure, but some of the nanofibers fly over and are only captured on the collecting electrode. Even by the embodiment in which the collecting electrode is formed by a conductive supporting linear structure, this problem is not eliminated. Also in this embodiment, most of the nanofibers fly over the linear supporting structure and are captured on the wall of the spinning space.

[0013] Although the nanofibers are captured between the fibers of the surface portion of the core, during their unwinding, the nanofiber coating is torn off the core due to the forces acting between the surfaces of adjacent fibers in the package (these forces are greater than the cohesive forces between the nanofiber coating and the core).

[0014] The above mentioned problems are partly solved by CZ PV 2009-797, in which the nanofibers are fixed to the core by means of at least one covering thread. For most possible applications, the wrapping by the covering thread ensures that the nanofibers are fixed to the core sufficiently firmly and durably, and at the same time, the covering thread allows full use of the specific properties of the nanofibers, since it does not hinder access to the nanofibers.

[0015] The actual fiber structure is produced by passing the supporting linear structure through the spinning space several times, wherein the supporting linear structure outside the spinning space returns through a part of the circumference of at least one cylinder, which is obliquely close to the cylinder so that after the return, the supporting linear structure faces the spinning electrode with its opposite side. In this embodiment, there is no false twist, and therefore, when passing through the spinning space, the supporting linear structure does not rotate around its axis, and therefore the nanofibers are deposited on the side of the supporting linear structure facing the spinning electrode during each pass. Due to the multiple passages of the supporting linear structure through the spinning space, a larger amount of nanofibers are deposited on the structure than in previous solutions, however some of the nanofibers fly by until they reach the collecting electrode. The nanofibers are deposited on the surface of the supporting linear structure as individual nanofibers in a layer in a disordered manner, and their cohesion with the core surface is low. The fixing of the nanofibers to the surface of the supporting linear structure is achieved by subsequent wrapping with at least one covering wire.

[0016] EP2931951 B1 discloses a method for producing polymer nanofibers, wherein polymer nanofibers are formed by applying an electric field to a polymer solution or melt placed on the surface of a spinning electrode, wherein the electric field for spinning is formed alternately between the spinning electrode to which an AC voltage is applied and air and / or gas ions generated and / or supplied near the spinning electrode without a collecting electrode, thereby, depending on the phase of the AC voltage on the spinning electrode, polymer nanofibers having opposite charges and / or having segments with opposite charges are formed, which after formation are aggregated into a linear structure in the form of a cable or a belt due to the action of electrostatic forces, and the cable or belt moves freely away from the spinning electrode in space in the direction of the gradient of the electric field.

[0017] Spinning by AC high voltage method is another way to produce nanofibers instead of electrospinning. However, its output has not yet reached the level of producing pure nanofiber yarn by this method. Therefore, EP3303666 proposes a method for producing a core yarn with a coating of polymer nanofibers, which surrounds the supporting linear structure forming the core during the support linear structure passing through the spinning chamber. In this method, a spinning electrode connected to the inlet of the polymer solution and powered by AC high voltage is arranged below the supporting linear structure, and on the face of the supporting linear structure, nanofibers are formed in the spinning space adjacent to the face of the spinning electrode and above it, wherein the supporting linear structure rotates around its own axis in the spinning space. Nanofibers are formed around the circumference of the face of the spinning electrode and in the spinning space. They are formed as hollow electrically neutral nanofiber feathers, wherein the nanofibers are arranged in an irregular grid structure in which the nanofibers in short sections change their directions, wherein the hollow electrically neutral nanofiber feathers are carried by the electric wind toward a supporting linear structure and become flat strips, which are brought to the circumference of the supporting linear structure, wherein the strips produced by the hollow electrically neutral nanofiber feathers are wrapped in a spiral shape around a rotating and / or ballooning supporting linear structure, producing a nanofiber coating thereon, wherein the nanofibers are arranged in an irregular grid structure in which the individual nanofibers in short sections change their directions.

[0018] Nanofiber hairiness represents an ideal material for coating of core yarns, since, due to its electrical neutrality and irregular grid structure in which individual nanofibers in short sections change their direction, the nanofiber hairiness is able to form a solid coating surrounding the yarn core, whereby the coating is inert to its surroundings when wound on a bobbin and during subsequent unwinding during processing. However, if pure nanofiber yarns are to be produced from nanofiber hairiness, there will be problems of insufficient number of nanofibers and of the grid structure of the hairiness, which does not allow parallelization of the nanofibers.

[0019] Currently, there is no satisfactory method to produce nanofiber yarns with potential for industrial applications. Current methods for preparing nanofiber yarns are hampered by low productivity, low reliability and limited material selection. Their production is only achieved on a laboratory scale as part of research work.

[0020] See, for example, Zhou B. et al., Developments in Electrospinning of Nanofibrous yarns, Journal of Physics: Conference Series 1790 (2021) 012081 doi: 10.1088 / 1742-6596 / 1790 / 1 / 012081).

[0021] The object of the present invention is to provide a method for producing nanofiber yarns by AC electrospinning of polymer solutions or melts, wherein the nanofibers will be produced in sufficient quantities, will be partially parallelized before twisting, and will be strong enough after twisting to allow winding on bobbins and subsequent use or processing into textile structures by known textile techniques.

[0022] Furthermore, it is an object of the present invention to provide a device for carrying out the method. Summary of the invention

[0023] The object of the present invention is achieved by a method for producing a linear nanofiber structure in an alternating electric field by spinning a polymer solution or melt, wherein the principle of the present invention is that at least one spinning area is generated on a spinning electrode with a supercritical AC electric field strength and a finite length, from which the emerging nanofibers are transported away from the spinning area toward a moving electrically neutral collector by the action of an electric wind in the direction of the maximum value of the electric field gradient, and on the circumferential surface of an electrically neutral collector located opposite the spinning area and forming a collecting area of ​​the moving electrically neutral collector, the nanofibers are deposited in the form of fluffy bands of nanofibers, which are moved into a drawing area by the movement of the electrically neutral collector, in which the fluffy bands of nanofibers are pulled out from the surface of the electrically neutral collector by tension and subsequently wound onto a bobbin of a winding device, the nanofibers being at least partially parallelized by tension.

[0024] In a preferred embodiment, the fluffy band of nanofibers is rounded during transfer to the pull-out zone on the surface of the electrically neutral collector, thereby tapering it so that it can be directly wound or more easily formed into a twisted triangle during tapering without the risk of damaging the edges of the fluffy band of nanofibers when twist is applied.

[0025] The tension for pulling out the fluffy band of nanofibers is generated by the winding device or the lead-out device arranged between the drawing area and the winding device. This separates the process tension from the winding force, so that the appropriate tension can be selected for the winding according to the configuration of the bobbin.

[0026] Before winding or drawing off, the fluffy ribbon of nanofibers is acted upon by a twisting device which tapers the fluffy ribbon of nanofibers into twisted triangles and then imparts twist thereto, thereby forming a nanofiber yarn.

[0027] A salient feature of the method is that twist is applied to the fluffy band of nanofibers between two clamping points (i.e., between the pull-out area of ​​the electrically neutral collector and the point at which the nanofiber yarn is wound or drawn out on the bobbin), wherein a residual amount of the twist applied to the fluffy band of nanofibers by the twisting device is retained in the nanofiber yarn that is wound after leaving the twisting device.

[0028] An important feature of the method according to the invention is also that the spinning area of ​​the spinning electrode is formed on the circumference of a disk spinning electrode, or at the bending point of a belt spinning electrode (wherein the spinning area is arranged transversely to the movement direction of the spinning belt), or on a linear flexible structure of a linear spinning electrode.

[0029] In order to carry out the method, a device for producing nanofiber yarn by AC electrospinning of a polymer solution or melt is provided, the principle of which is that an electrically neutral collector coupled to a drive is arranged above a spinning electrode in the path of the nanofibers, wherein the area of ​​the surface of the electrically neutral collector facing the spinning electrode forms a collection area for the nanofibers for continuous deposition of the nanofibers in the form of a fluffy band of nanofibers, wherein a pull-out area for the fluffy band of nanofibers is formed on the surface of the electrically neutral collector in the moving direction of the collector downstream of the collection area, and downstream of the collection area, a winding device is arranged in the pull-out direction of the fluffy band of nanofibers. The winding device is used to generate a pulling force to pull the fluffy band of nanofibers from the surface of the electrically neutral collector.

[0030] The tension can also be generated by a take-off device located between the take-off area and the winding device. In this way, it is possible to separate the process tension (i.e. the tension associated with making the yarn balloon and the pull-out strength) and the winding tension (i.e. the winding tension). The appropriate winding tension can then be selected for the configuration of the bobbin.

[0031] In a preferred embodiment, upstream of the winding device or the withdrawal device, a twisting device is arranged in the direction of pull-out of the fluffy band of nanofibers so that the nanofiber yarn is fed into the winding device.

[0032] The spinning electrode can be formed by a disk spinning electrode, a belt spinning electrode or a linear spinning electrode or by another type of spinning electrode.

[0033] The electrically neutral collector may consist of an electrically neutral drum collector or an electrically neutral belt collector.

[0034] If the electrically neutral collector is formed by an electrically neutral drum collector, then in a preferred embodiment, a collection area for the nanofibers is formed on the electrically neutral drum collector facing the spinning electrode, and a pulling-out area of ​​the drum collector is formed in the area on the surface of the drum collector facing away from the spinning electrode, for pulling out a fluffy band of nanofibers.

[0035] In this embodiment, it is advantageous if a rounding device is assigned to the fluffy band of nanofibers between the collecting area and the pull-off area of ​​the electrically neutral drum collector. The rounding device reduces the width / thickness of the fluffy band of nanofibers and thus simplifies its twisting and / or winding.

[0036] If the electrically neutral collector is formed by a belt collector, the collector is an endless conveyor belt encircling two upper cylinders and two lower cylinders, at least one of which is a driving cylinder. The lower branch of the endless conveyor belt forms a collection area for the nanofibers, which are deposited on the collection area as a fluffy belt of nanofibers.

[0037] In a preferred embodiment, the fluffy band of nanofibers is fed into the upper branch of the endless conveyor by the movement of the endless conveyor, the end of which in the movement direction of the endless conveyor forms a pull-out area for pulling out the fluffy band of nanofibers from the electrically neutral belt collector. This embodiment allows the allocation of a rounding device to the fluffy band of nanofibers on the upper branch of the endless conveyor, which tapers the fluffy band of nanofibers and improves its properties for pulling out and subsequent twisting.

[0038] In another preferred embodiment, a pulling-out area is formed at the end of the lower branch of the endless conveyor belt in the moving direction of the endless conveyor belt, for pulling out a fluffy belt of nanofibers from an electrically neutral belt collector, which is connected to the collecting area formed by the lower branch of the endless conveyor belt, and the nanofibers are deposited on the collecting area in the form of a fluffy belt. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In the accompanying drawings, a device according to the invention is schematically represented, wherein: Figure 1 shows a side view of an apparatus having a rotating disk spinning electrode and an electrically neutral drum collector, Figure 2 The previous view shows Figure 1 equipment, Figure 3 Shown in top view Figure 1 equipment, Figure 4 shows the distribution of the electric field strength on the circumference of the disk electrode, Figure 5shows a side view of an apparatus having a rotating disk spinning electrode and an electrically neutral belt collector, Figure 6 The previous view shows Figure 5 equipment, Figure 7 Shown in top view Figure 5 equipment, Figure 8a The apparatus with a belt spinning electrode and an electrically neutral belt collector is shown in a side view, with the pull-off area of ​​the fluffy belt of nanofibers in the upper branch of the collector, Figure 8b The previous view shows Figure 8a equipment, Figure 8c A device with a belt spinning electrode and an electrically neutral belt collector is shown in a side view, with a pull-off zone for the fluffy belt of nanofibers in the lower branch of the collector, Figure 8d Shows Figure 8c Front view of the device, Figure 9a A side view of a device with a linear spinning electrode and an electrically neutral belt collector is shown, with a pull-off zone of a fluffy belt of nanofibers in the upper branch of the collector, Figure 9b Shows Figure 9a Front view of the device, Fig.9c A side view of a device with a linear spinning electrode and an electrically neutral belt collector is shown, with a pull-off zone of a fluffy belt of nanofibers in the lower branch of the collector, Figure 9d Shows Fig.9c Front view of the device. DETAILED DESCRIPTION

[0040] An apparatus for producing nanofibers by AC electrospinning of a polymer solution or a polymer melt comprises a spinning electrode 1, Figures 1 to 7 In the embodiment of the present invention, the spinning electrode 1 is composed of a rotating disk spinning electrode 11, which is installed in a reservoir 2 of a polymer solution 21 or a melt at the lower part of its circumference and is connected to a known drive (not shown). Since the spinning of the polymer melt is carried out in the same manner as the spinning of the polymer solution 21, only the spinning of the polymer solution will be described below. The polymer solution is generally composed of a solution of PVB, PCL, PVA or other spinnable polymer solutions. The spinning electrode 1 and the reservoir 2 of the polymer solution are installed in a spinning chamber 3.

[0041] The spinning electrode 1 is connected to a high voltage AC source (not shown) having, for example, an effective voltage of 32 kV and a frequency of 50 Hz. Connected to the AC voltage source may also be a polymer solution to be spun, through which the spinning electrode 1 and the AC voltage source are interconnected. According to a first exemplary embodiment, the spinning electrode 1 is formed by a rotating disk spinning electrode 11 having a horizontal axis of rotation. The rotating disk spinning electrode 11 is installed in a polymer solution 21 in a reservoir 2 at the lower part of its circumference. The rotating disk spinning electrode 11 is connected to a known, not shown, rotary drive so that during its rotation, it conveys the polymer solution 21 to the circumferential part of its surface. The amount of the polymer solution 21 is usually adjusted by a known, not shown, wiping device. In the rotating chamber 3, near and above the upper part of the circumference of the disk spinning electrode 11, there is a spinning space 31. Above the spinning electrode 1 in the spinning chamber 3, an electrically neutral collector 4 connected to a known drive (not shown) is rotatably mounted. The upper part of the disk spinning electrode 11 forms a spinning area 110, in which nanofibers 5 are formed. The nanofibers 5 are transported through the spinning space 31 to the surface of the electrically neutral collector 4 covered with a suitable coating, for example, by a flat textile made of a material that allows the nanofibers to be easily pulled out from the surface of the electrically neutral collector 4.

[0042] exist Figures 1 to 3 In the embodiment of the present invention, the collector 4 is formed by an electrically neutral roller collector 41. The axis of the electrically neutral roller collector 41 is parallel to the axis of the disk spinning electrode 11. The area of ​​the surface of the electrically neutral roller collector 41 facing the disk spinning electrode 11 forms a collection area 410 for nanofibers, and the nanofibers 5 are deposited on the collection area 410 in the form of fluffy bands 51 of nanofibers. The area of ​​the surface of the electrically neutral roller collector 41 facing away from the disk spinning electrode 11 forms a pull-out area 4101 for the fluffy bands 51 of nanofibers.

[0043] Outside the spinning space 31, in the tangential direction of the circumference of the electrically neutral drum collector 41 and in the flow direction of the drawn nanofibers 5, a twisting device 6 is arranged, which, for example, consists of a rotating guide eyelet located outside the rotation axis of the twisting device 6 or another known twisting device. A winding device 7 with a bobbin 71 is arranged downstream of the twisting device 6 in the flow direction of the drawn nanofibers 5 and in the withdrawal direction of the yarn 54. In an exemplary embodiment not shown, a withdrawal device is arranged between the withdrawal area 4101 and the winding device 7, which withdrawal device is used to generate a tensile force for pulling the fluffy band 51 of nanofibers from the surface of the electrically neutral collector.

[0044] The effective value of the voltage (eg 32 kV), the waveform of the voltage function (eg sine, sawtooth, step) and the frequency (eg 50 Hz) are not limiting, and other suitable values ​​may be used within a very wide range.

[0045] During rotation, the disk spinning electrode 11 conveys the polymer solution 21 from the reservoir 2 over its circumference and parts of its face near the circumference. During spinning in the AC electric field, the aim is to produce the maximum possible amount of nanofibers 5 per unit time, which are formed in the entire spinning area 110 of the disk spinning electrode 11 and conveyed from the disk spinning electrode 11 to an electrically neutral drum collector 41, which is neither grounded nor connected to a source of voltage, by an electric wind (optionally also by an auxiliary air flow) in the direction of the gradient of the generated electric field. The formation of the nanofibers 5 begins at a critical value of the electric field strength E, which varies depending on the type of polymer solution 21 to be spun, the value of the voltage, the waveform, the frequency of the AC voltage, the quality of the gas in the spinning chamber 3 and other parameters. At a value of the electric field strength E below the critical value, the nanofibers 5 are not formed or stop forming.

[0046] The critical value of the electric field strength E for AC electrospinning purposes means the minimum value of the electric field strength E which, for a given shape of spinning electrodes, type of polymer solution and value and waveform of the frequency, will provide a sufficient amount of nanofibers for further processing.

[0047] Therefore, during conventional spinning in an AC electric field of a specific design using the spinning electrode 1, an electric field strength E higher than the critical strength (i.e., a supercritical electric field strength) is used for the selected frequency of the electric field and its waveform, which produces an electric field of high intensity E on the spinning electrode 1 in order to prevent the risk of interruption of the spinning process, to ensure sufficient evaporation of the solvent from the emerging Taylor cone of the polymer solution, and to provide a sufficiently strong electric wind to transport the formed nanofibers 5 to the electrically neutral collector 4.

[0048] For a disk diameter of 300 mm, a disk thickness of 1 mm, a polymer solution layer thickness of 0.2 mm and a voltage amplitude of 50 kV, the distribution of the electric field strength E for conventional spinning of the above-mentioned polymer solution 21 on the disk spinning electrode 11 is Figure 4. The supercritical value of the electric field strength E of the PVB polymer solution is equal to or greater than 3000 MV / m. It is obvious from the figure that the supercritical value of the electric field strength E is obtained in a wide area around the circumference of the disk spinning electrode 11. Therefore, the spinning of the polymer solution 21 occurs over the entire width of the circumferential surface of the disk spinning electrode 11 and on a portion of the surface near its circumference, and the formed nanofibers 5 are transported away from the disk spinning electrode 11 in the direction of the gradient of the generated electric field, through the spinning space 31 to the surface of the electrically neutral drum collector 41, to its collection area 410, and if necessary, the effect of the electric wind is assisted by causing the air to flow in the desired direction. Given the size of the area of ​​supercritical electric field strength E, it is obvious that a sufficient amount of nanofibers 5 will be produced for their further processing.

[0049] The nanofibers 5 are deposited as narrow fluffy bands 51 of nanofibers on the circumferential collection area 410 of the electrically neutral drum collector 41, and the fluffy bands 51 of nanofibers are transported to the upper part of the electrically neutral drum collector 41, i.e., to the pull-out area 4101, by rotating the drum collector 41, where the fluffy bands 51 of nanofibers are pulled out in the pull-out area 4101. The fluffy bands 51 of nanofibers produced by AC electrospinning consist of three-dimensional layers of nanofibers 5, which are deposited on the surface of the electrically neutral drum collector 41 due to the action of the electric wind and the attraction between oppositely polarized parts of the nanofibers 5, and are partially parallelized during deposition, wherein the fluffy bands 51 of nanofibers represent a linear nanofiber structure. The fluffy band 51 of nanofibers can be pulled out from the surface of the pull-out area 4101 of the electrically neutral drum collector 41 in a three-dimensional shape, and by subsequently drawing it out and twisting it, a twisted triangle 52 and a nanofiber yarn 54 can be formed therefrom in a manner similar to when processing fiber strands with permanent twist on the yarn.

[0050] If nanofibers are produced by DC electrospinning on a similar apparatus, a drum collector will serve as a collecting electrode connected to a DC voltage of opposite polarity to the spinning electrode, and the nanofibers will be deposited thereon as a flat, very thin ribbon which, after being pulled from the drum and subsequently subjected to twisting, will appear as a solid flat structure and will twist into a helix formed by the ribbon.

[0051] The circumferential speed of the electrically neutral drum collector 41 is adjusted so that the fluffy band 51 of nanofibers produced on the drum collector 41 has sufficient mechanical resistance when it is pulled out from the surface of the electrically neutral drum collector 41 in the pull-out area 4101 and is used for the subsequent application of twist, or for direct winding onto the bobbin 71 of the winding device 7.

[0052] The fluffy band 51 of nanofibers is pulled out from the rotating electrically neutral drum collector 41 and guided to the twisting device 6, wherein after being pulled out, it gradually tapers into the twisting triangle 52, and under the action of the twisting device 6 and the torque transmitted from the partially twisted nanofibers 5 from the twisting device 6, the fluffy band 51 of nanofibers gradually tapers from the twisting triangle 52 and is simultaneously twisted into the nanofiber yarn 54. Since the nanofibers 5 of the fluffy band 51 of nanofibers are deposited on the surface of the electrically neutral drum collector 41 with a certain degree of adhesion, when the nanofibers 5 are released from the surface of the electrically neutral drum collector 41 in the pull-out area 4101, a tensile force is generated in the nanofibers 5, which is necessary to parallelize the nanofibers 5 before twisting, so that the formation of twist and thus the formation of the nanofiber yarn 54 occurs after the nanofibers are partially parallelized. Furthermore, the pulling out of the fluffy band 51 of nanofibers from the surface of the electrically neutral drum collector 41 occurs due to the stretching between two clamping points, namely between the surface of the drum collector 41 and the winding point on the bobbin 71, the nanofibers 5 are elongated and partially parallelized in their flow direction, which facilitates the arrangement of the nanofibers 5 into a spiral when they are subsequently twisted and thus ensures sufficient strength of the produced nanofiber yarn 54.

[0053] During twisting, the nanofibers are no longer parallelized, but twisted into a spiral. If the pull-out is performed at a speed greater than the speed of the collector, at the moment of pull-out the nanofibers will straighten and stretch / elongate, but then immediately begin to twist into a spiral in the twist triangle.

[0054] After the nanofiber 5 is pulled out from the pull-out region 4101 of the electrically neutral drum collector 41, the pulled-out fluffy band 51 of the nanofiber is formed into a twisting triangle 52 by the twisting device 6 and into a nanofiber yarn 54 from the twisting triangle 52, wherein the nanofiber yarn 54 forms an air loop before entering the twisting device 6. The twist propagates from the twisting device 6 toward the electrically neutral drum collector 41 against the process direction of the flow of the nanofiber 5, thereby facilitating the pulling out of the fluffy band 51 of the nanofiber from the pull-out region 4101 of the drum collector 41.

[0055] The twisting device 6 applies twist to the nanofiber yarn 54 between two clamping points (i.e. between the pull-out zone and the point of winding or withdrawal) so that in the case of yarns from conventional fibers, a false twist would occur, which in the case of yarns from conventional fibers would be eliminated after passing through the twisting device. This does not apply to the twisting of the nanofiber yarn 54, since due to the high surface area of ​​the nanofibers 5, the bonding forces between the individual nanofibers 5 and the low twist coefficient, a relatively high twist remains on the nanofiber yarn 54 downstream of the twisting device 6 as a residual amount of twist. According to experiments conducted on nanofibers made of different types of polymers, it is 10% to 60% of the twist, and it is therefore a permanent twist. In specific tests, at a twisting device speed of about 10,000 rpm, the residual twist was about 1,400 twists / meter of yarn length. Subsequently, in the winding device 7, the nanofiber yarn 54 is wound onto a bobbin 71 in a known manner.

[0056] In order to increase the strength and uniformity of the produced nanofiber yarn 54, it is advantageous to round the fluffy band 51 of nanofibers on the surface of the roller collector 41 before pulling it out from the electrically neutral roller collector 41, thereby achieving the narrowing of the fluffy band 51 of nanofibers, the more uniform action of the force holding the nanofibers 5 on the surface of the electrically neutral roller collector 41, and the easier pulling out of the nanofibers 5 in the pulling-out area 4101 of the electrically neutral roller collector 41 in the entire cross section of the fluffy band 51 of nanofibers, and their smooth transition to the twisting triangle 52. At the same time, the rounding reduces the bottom of the twisting triangle 52, thereby reducing the tension in the circumferential portion of the fluffy band 51 of nanofibers, and thus reducing the risk of breaking the fluffy band 51 of nanofibers during pulling out from the pulling-out area 4101 of the electrically neutral roller collector 41. The linear structure formed by rounding the fluffy band 51 of nanofibers can also be used for direct winding onto the bobbin 71 of the winding device 7 without being twisted on the twisting device 6.

[0057] A further increase in the strength of the produced nanofiber yarn 54 can be achieved, for example, by twisting the nanofiber yarn 54 with a permanent twist on a suitable device (not shown).

[0058] The amount of nanofibers 5 formed, the circumferential speed of the electrically neutral drum collector 41 and the withdrawal speed of the fluffy band 51 of nanofibers determine the linear quality of the nanofiber yarn 54 , which is crucial to the resulting strength of the nanofiber yarn 54 .

[0059] Figures 5 to 7, in which the electrically neutral collector 4 is formed by a belt collector 42 arranged in the spinning chamber 3 above the rotating disk spinning electrode 11. The belt collector 42 comprises an endless conveyor belt 421 which is wound around two upper cylinders 422 and two lower cylinders 423, wherein at least one cylinder 422, 423 is a driving cylinder. The rotation axes of all cylinders 422, 423 of the belt collector 42 are parallel to the rotation axis of the disk spinning electrode 11. Figures 5 to 7 In the embodiment of the embodiment, the endless conveyor 421 moves counterclockwise, wherein its lower branch 4211 located between the lower cylinders 423 is arranged opposite to the spinning area 110 of the rotating disk spinning electrode 11, and the nanofibers 5 formed in the spinning area 110 of the rotating disk spinning electrode 11 are deposited into a fluffy band 51 of nanofibers on the lower branch of the endless conveyor 421. The lower branch 4211 of the endless conveyor 421 thus forms the collecting area 420 of the electrically neutral belt collector 42. Due to the moving direction of the endless conveyor 421, in this embodiment, the fluffy band 51 of nanofibers is conveyed to the upper branch 4212 of the endless conveyor 421, the end of which forms the drawing area 4201 of the electrically neutral belt collector 42, from which the fluffy band 51 of nanofibers is drawn and guided to the twisting device 6, by which twist is applied to the fluffy band. After being pulled out, the fluffy band 51 of nanofibers tapers into a twisted triangle 52 due to the effect of the twist, and is subsequently formed into a nanofiber yarn 54, as described in the previous variant of the device with an electrically neutral drum collector 41. This arrangement allows a larger amount of nanofibers 5 to be deposited on the electrically neutral belt collector 42, thereby forming a fluffy band 51 of nanofibers with greater thickness and weight. In addition, this arrangement provides sufficient space on the upper branch 4212 of the endless conveyor 421 for rounding the fluffy band 51 of nanofibers by a known, not shown, rounding device. If the endless conveyor 421 moves in the opposite direction, the pull-out area 4201 will be formed again at the end of the upper branch 4212 of the endless conveyor 421, but according to the figure, it will be on the right-hand side.

[0060] In an alternative embodiment of this arrangement not shown, it is possible to change the position of the pull-out area 4201 of the fluffy band 51 of nanofibers by changing the direction of rotation of the drive cylinders of the cylinders 422, 423 around which the endless conveyor belt 421 is wrapped, and place the pull-out area 4201 of the fluffy band 51 of nanofibers at the end of the lower branch 4211 in the direction of movement of the endless conveyor belt 421. Thus, the deposition of nanofibers 5, the formation of the fluffy band 51 of nanofibers and their pull-out take place on the lower branch 4211 of the endless conveyor belt 421 of the electrically neutral belt collector 42, the upper branch 4212 being empty.

[0061] In accordance with Figures 5 to 7 In the arrangement of the device, the rotating disk spinning electrode 11 can be replaced by a spinning electrode with a direct spinning area, which can be composed of a belt spinning electrode 12 or a linear spinning electrode 13 formed by a linear flexible structure, which will be described below.

[0062] exist Figures 8a to 8d , a device with a belt spinning electrode 12 is shown. The device comprises a reservoir 2 for a polymer solution 21, into which a rewinding shaft 8 connected to a drive 81 extends with a part of its circumference. Above the rewinding shaft 8, a scraper 121 is fixedly mounted in a spinning chamber 3 on a frame of the device, for example by means of a support 82. The rewinding shaft 8 together with the scraper 121 is wrapped by spinning ribbons 122, 122, which extend from the polymer solution 21 and bend over the rewinding shaft 8 on the scraper 121. The spinning ribbon 122 transports the polymer solution 21 out of the reservoir 2, and the bend of the spinning ribbon 122 forms a spinning area 120 of the belt spinning electrode 12, which is connected to an AC voltage source. Above the spinning area 120 of the belt spinning electrode 12, a lower branch 4211 of an endless conveyor belt 421 of an electrically neutral belt collector 42 is arranged at least along its entire width, as shown in FIG. Figure 8b as shown in .

[0063] The electrically neutral belt collector 42 is based on Figures 5 to 7 The belt collector 42 comprises an endless conveyor belt 421 which is wound around two upper cylinders 422 and two lower cylinders 423, wherein at least one cylinder 422, 423 is a driving cylinder. The rotation axes of all cylinders 422, 423 of the belt collector 42 are perpendicular to the rotation axis of the rewinding shaft 8. Figure 8a , Figure 8bIn the embodiment of the embodiment, the endless conveyor 421 moves counterclockwise, wherein the lower branch 4211 of the endless conveyor located between the lower cylinders 423 is arranged opposite to the spinning area 120 of the belt-type spinning electrode 12, and the nanofibers 5 formed in the spinning area 120 of the belt-type spinning electrode 12 are deposited on the lower branch of the endless conveyor 421 as a fluffy band 51 of nanofibers. The lower branch 4211 of the endless conveyor 421 represents the collecting area 420 of the electrically neutral belt collector 42. In this embodiment, relative to the moving direction of the endless conveyor 421, the fluffy band 51 of nanofibers is transported to the upper branch 4212 of the endless conveyor 421, the end of which forms the drawing area 4201 of the electrically neutral belt collector 42, the fluffy band 51 of nanofibers is drawn out from the drawing area and guided to the twisting device 6 in the direction of the arrow, by which the fluffy band 51 is given a twist. After being drawn off, the fluffy band 51 of nanofibers tapers due to the twist into a twisted triangle 52 and subsequently forms a nanofiber yarn 54 therefrom, as described in the previous variant of the device with an electrically neutral drum collector 41. As already described above, the direction of movement of the endless conveyor belt can be reversed and the above mentioned arrangement is only a lateral reversal.

[0064] Figure 8c and Figure 8d An alternative embodiment of this arrangement of an apparatus for producing nanofiber yarns is shown in FIG. In this embodiment, the direction of rotation of the drive cylinders 422, 423 around which the endless conveyor 421 is wrapped is reversed so that the endless conveyor moves clockwise, as shown in FIG. Figure 8d The rest of the equipment and its functions remain the same. Figure 8a and Figure 8b is the same as in the embodiment of . Therefore, the deposition of nanofibers 5, the formation of fluffy bands 51 of nanofibers and their pulling out occur on the lower branch 4211 of the endless conveyor 421 of the electrically neutral belt collector 42, and the upper branch 4212 is empty. The pulling-out area 4201 of the electrically neutral belt collector 42 is therefore at the end of the lower branch 4211 of the endless conveyor 421, and in the pulling-out area 4201, the fluffy bands 51 of nanofibers are pulled out from the endless conveyor 421. As described above, the fluffy bands 51 of nanofibers are fed from the pulling-out area 4201 in the direction of the arrow to the twisting device, where they are twisted into nanofiber yarns 54. As already described above, the moving direction of the endless conveyor can be reversed, and the above-mentioned arrangement is only a lateral reversal.

[0065] In the embodiment with the linear spinning electrode 13, the linear spinning electrode 13 is composed of a ring-shaped linear flexible structure. Figures 9a to 9dIn the embodiment shown in the figure, the annular linear flexible structure is mounted on two rotatably mounted pulleys 131, which are coupled to a drive not shown. At least one of the pulleys 131 extends with a portion of its circumference to the reservoir 2 of the polymer solution 21. In the embodiment shown, each pulley 131 has its reservoir 2 of the polymer solution 21.

[0066] The linear flexible structure consisting of the linear spinning electrode 13 can be formed by, for example, a thin wire, a belt, a ribbon, or a structure having a more dispersed surface composed of multiple interwoven parts (such as a cable, a rope, a multi-core formation, etc.). Similar to the previous embodiment, a spinning area 130 of limited length is formed on the linear spinning electrode 13 between pulleys 131. The spinning area 130 is connected to an AC voltage source by one of the known methods.

[0067] An electrically neutral belt collector 42 is arranged above the spinning area 130 of the linear spinning electrode 13, and its lower branch 4211 is arranged at least above the entire length of the spinning area 130 of the linear spinning electrode 13. Figure 9b and Figure 9d . The electrically neutral belt collector 42 is constructed similarly to the previous embodiment and comprises an endless conveyor belt 421 which surrounds two upper cylinders 422 and two lower cylinders 423, wherein at least one cylinder 422, 423 is a driving cylinder. The axes of rotation of all cylinders 422, 423 of the belt collector 42 are parallel to the axis of the pulley 131. Figure 9a , Figure 9b In the embodiment of the embodiment, the endless conveyor 421 moves counterclockwise, wherein its lower branch 4211 located between the lower cylinders 423 is arranged opposite to the spinning area 130 of the linear spinning electrode, and the nanofibers 5 formed in the spinning area 130 of the linear spinning electrode 13 are deposited on the lower branch of the endless conveyor 421 as a fluffy band 51 of nanofibers. The lower branch 4211 of the endless conveyor 421 thus represents the collecting area 420 of the electrically neutral belt collector 42. In this embodiment, relative to the moving direction of the endless conveyor 421, the fluffy band 51 of nanofibers is transported to the upper branch 4212 of the endless conveyor 421, the end of which forms the drawing area 4201 of the electrically neutral belt collector 42, the fluffy band 51 of nanofibers is drawn out from the drawing area and guided into the twisting device 6 in the direction of the arrow, and by twisting it, the nanofiber yarn is formed. As mentioned above, the direction of movement of the endless conveyor belt can be reversed, and the above mentioned arrangement is only a sideways reversal.

[0068] Fig.9c and Figure 9dAn alternative embodiment of such an arrangement of an apparatus for producing nanofiber yarns is shown in FIG. In this embodiment, the direction of movement of the endless conveyor belt 421 is changed, and thus it moves clockwise, as shown in FIG. Figure 9d The rest of the equipment and its functions remain the same as in Figure 9a and Figure 9b is the same as in the embodiment of . Therefore, the deposition of nanofibers 5, the formation of fluffy bands 51 of nanofibers and their pulling out are on the lower branch 4211 of the endless conveyor 421 of the electrically neutral belt collector 42, and the upper branch 4212 is empty. The pulling-out area 4201 of the electrically neutral belt collector 42 is therefore at the end of the lower branch 4211 of the endless conveyor 421. The fluffy band 51 of nanofibers is fed from the pulling-out area 4201 to the twisting device in the direction of the arrow, and the nanofiber yarn is formed by twisting it. As mentioned above, the moving direction of the endless conveyor can be reversed, and the above-mentioned arrangement is only a lateral reversal.

[0069] In an embodiment with a linear spinning electrode 13, the annular linear flexible structure can be replaced by a linear flexible structure of limited length wound on pulleys 131. In this embodiment, two pulleys 131 extend at the lower part of their circumference to the polymer solution 21. The pulleys 131 are coupled to a known, not shown, reciprocating drive and rotate alternately in two directions, with the linear flexible structure held taut between them.

[0070] Industrial Applicability

[0071] Yarns and threads made of fibers are the most commonly used structural elements in the textile industry for the production of various types of textiles, such as fabrics and knitwear. The use of 100% nanofiber yarns in conventional textile production methods represents a huge potential for the production of so-called nanotextiles, which exhibit excellent optical, electrical, mechanical and biological properties due to effects associated with their extremely large specific surface area and low flexibility (flexural modulus).

[0072] Nanofiber yarns will find applications as building blocks for surgical threads, tissue carriers for repairing nerves, tendons, bones, and blood vessels. They have the potential to become structural elements for energy harvesting and storage, actuators for mechatronic devices, and for sensors and filters.

[0073] Reference numerals list

[0074] 1 Spinning electrode

[0075] 11 Rotating disk spinning electrode

[0076] 110 Spinning area of ​​rotating disk spinning electrode

[0077] 12 Belt Spinning Electrode

[0078] 120 Spinning area of ​​belt spinning electrode

[0079] 121 Scraper

[0080] 122 Spinning Ribbon

[0081] 13 Linear Spinning Electrode

[0082] 130 Spinning area of ​​linear spinning electrode

[0083] 131 Pulley

[0084] 2 Reservoir for polymer solution

[0085] 21 Polymer solution

[0086] 3 Spinning room

[0087] 31 Spinning Space

[0088] 4 Charge-neutral collector

[0089] 40 Collection area of ​​the neutral collector

[0090] 401 Pull-out area of ​​electrically neutral collector

[0091] 41 Drum Collector

[0092] 410 Collection area of ​​the drum collector

[0093] 4101 Pull-out area of ​​the drum collector

[0094] 42 Belt collector

[0095] 420 Collection area of ​​belt collector

[0096] 4201 belt collector pull-out area

[0097] 421 Endless conveyor belt

[0098] 4211 Lower branch of the endless conveyor belt

[0099] 4212 Upper branch of the ring conveyor belt

[0100] 422 Upper Cylinder

[0101] 423 Lower Cylinder

[0102] 5 Nanofibers

[0103] 51 Fluffy ribbons of nanofibers

[0104] 52 Twisting triangle

[0105] 54 Nanofiber Yarn

[0106] 6 Twisting equipment

[0107] 7 Winding equipment

[0108] 71 Bobbin

[0109] 8 Rewinding shaft

[0110] 81 Driver

[0111] 82 Pillar

[0112] E Electric field strength

Claims

1. A method for producing a linear nanofiber structure from a polymer solution or melt in an AC electric field, wherein: A spinning region (110, 120, 130) with a supercritical AC electric field strength E is formed on a spinning electrode (1, 11, 12, 13), wherein nanofibers (5) are formed in the spinning region (110, 120, 130), and the nanofibers (5) are transported away from the spinning electrode in the direction of the maximum value of the gradient of the generated electric field by the action of an electric wind, characterized in that at least one spinning region (110, 120, 130) with a supercritical AC electric field strength (E) and a finite length is formed on a linear spinning electrode, wherein the nanofibers (5) emerging from the spinning region (110, 120, 130) are transported away from the spinning region toward a moving electrically neutral collector (4, 41, 42) are transported, and on the circumferential surface of the electrically neutral collector (40, 410, 420) located opposite to the spinning area and forming the moving electrically neutral collector (4, 41, 42), the nanofibers (5) are deposited in the form of fluffy bands (51) of nanofibers, and the fluffy bands (51) are continuously moved to the drawing-off area (401, 4101, 4201) by the movement of the electrically neutral collector (4, 41, 42), in which the fluffy bands (51) are pulled out from the surface of the electrically neutral collector (4, 41, 42) by tension and are subsequently wound onto a bobbin (71) of a winding device (7), wherein the nanofibers (5) are at least partially parallelized due to the tension.

2. The method according to claim 1, characterized in that The fluffy band (51) of nanofibers is rounded during transfer to the pull-out region (401, 4101, 4201) on the surface of the electrically neutral collector (4, 41, 42) and thereby narrowed into a ribbon of nanofibers.

3. The method according to claim 1 or 2, characterized in that: During said drawing out of said fluffy strip (51) of nanofibers, a tensile force is generated by a winding device (7).

4. The method according to claim 1 or 2, characterized in that: During said drawing-out of said fluffy strip (51) of nanofibers, a tensile force is generated by a drawing-off device arranged between said drawing-out zone and said winding device.

5. The method according to any one of the preceding claims 1 to 4, characterized in that Upstream of the winding device (7) or the lead-out device, the fluffy band (51) of nanofibers is acted upon by a twisting device (6), which gradually tapers the fluffy band (51) of nanofibers into a twisting triangle (52) and then applies twist to it, thereby forming a nanofiber yarn (54).

6. The method according to claim 5, characterized in that After leaving the twisting device (6), a residual amount of twist applied to the fluffy band (51) of nanofibers by the twisting device (6) is retained, thereby forming a nanofiber yarn (54).

7. An apparatus for producing linear nanofibrous structures from polymer solutions or melts in an AC electric field using a method according to any one of the preceding claims 1 to 6, wherein: A spinning area (110, 120, 130) having a supercritical value of the AC electric field strength (E) is generated on a spinning electrode (1, 11, 12, 13), the spinning electrode (1, 11, 12, 13) being installed in a spinning chamber and connected to a high voltage AC source and connected to a device for applying the polymer solution or melt to the surface of the spinning electrode, characterized in that above the spinning electrode (1, 11, 12, 13), an electrically neutral collector (4, 41, 42) connected to a drive is arranged in the path of the nanofibers (5), wherein the surface of the electrically neutral collector (4, 41, 42) forms a nanofiber (5) in the area facing the spinning electrode (1, 11, 12, 13). A collecting area (40, 410, 420) for meter fibers is used for continuous deposition of nanofibers in the form of a fluffy band (51) of nanofibers, wherein a pull-out area (401, 4101, 4201) of the fluffy band (51) of nanofibers is formed downstream of the collecting area on the surface of the electrically neutral collector (4, 41, 42) in the moving direction of the collector, and a winding device (7) is arranged downstream of the pull-out area (401, 4101, 4201) in the pulling-out direction of the fluffy band (51) of nanofibers (5) for generating the fluffy band (51) for pulling the nanofibers from the surface of the electrically neutral collector (4, 41, 42).

8. The device according to claim 7, characterized in that A lead-out device is arranged between the pull-out area (401, 4101, 4201) and the winding device (7), and is used to generate a pulling force for pulling the fluffy strip (51) of nanofibers from the surface of the electrically neutral collector (4, 41, 42).

9. The device according to claim 7 or 8, characterized in that A twisting device (6) is arranged upstream of the winding device (7) or the withdrawal device in the direction of drawing out the fluffy band (51) of nanofibers.

10. The device according to any one of claims 7 to 9, characterized in that The spinning electrode is formed by a rotating disk spinning electrode (11).

11. The device according to any one of claims 7 to 9, characterized in that The spinning electrode is formed by a belt spinning electrode (12).

12. The device according to any one of claims 7 to 9, characterized in that The spinning electrode is formed by a linear spinning electrode (13).

13. The device according to any one of claims 7 to 12, characterized in that The electrically neutral collector is formed by an electrically neutral drum collector (41).

14. The device according to claim 13, characterized in that On the electrically neutral roller collector (41), a collection area (410) of the nanofibers (5) of the electrically neutral roller collector (41) is formed in an area facing the spinning electrodes (1, 11, 12, 13), and a pulling-out area (4101) of the roller collector is formed in an area on the surface of the roller collector (41) facing away from the spinning electrodes (1, 11, 12, 13) for pulling out the fluffy band (51) of nanofibers.

15. The device according to claim 14, characterized in that Between the collecting area (410) and the pulling-off area (4101) of the electrically neutral drum collector (41), the fluffy band (51) of nanofibers is allocated with rounding means.

16. The device according to any one of claims 7 to 12, characterized in that The electrically neutral collector is formed by an electrically neutral belt collector (42).

17. The device according to claim 16, characterized in that The electrically neutral belt collector (42) comprises an annular conveyor belt (421) which surrounds two upper cylinders (422) and two lower cylinders (423), at least one of the two upper cylinders (422) and the two lower cylinders (423) being a driving cylinder, wherein the lower branch (4211) of the annular conveyor belt (421) forms the collection area (420) of the nanofibers (5) for depositing the nanofibers in the fluffy belt (51) of the nanofibers.

18. The device according to claim 17, characterized in that The endless conveyor belt (421) has an upper branch, and the end of the upper branch in the moving direction of the endless conveyor belt (421) forms a pull-out area (4201) for pulling out the fluffy belt (51) of nanofibers from the electrically neutral belt collector (42).

19. The device according to claim 18, characterized in that On the upper branch (4212) of the endless conveyor belt (421), the fluffy band (51) of nanofibers is assigned a rounding device.

20. The device according to claim 17, characterized in that In the direction of movement of the circular conveyor belt (421), at the end of the lower branch (4211) of the circular conveyor belt (421), the pulling-out area (4201) for pulling out the fluffy belt (51) of the nanofibers from the electrically neutral belt collector (42) is generated, and the electrically neutral belt collector (42) is connected to the collecting area (420) formed by the lower branch (4211) of the circular conveyor belt (421) for depositing the nanofibers (5) in the form of a fluffy belt (51).

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