CZ304660B6 - Method of and device for producing fiber layer, especially nanofiber layer, microfiber layer or mixtures thereof with fibers oriented in one direction and collector of such device for laying fibers - Google Patents

Abstract

The invented method of producing fiber layer with fibers (20) oriented in one direction is characterized in that the fibers (20) are produced by electrostatic spinning of a polymer solution or a polymer melt in an electric field generated between at least one spinning electrode (2) and at least one collecting electrode (3). The fibers are then laid in a layer on the surface of collecting elements (52) of a collector (5) closed into an endless loop, wherein the collecting elements (52) are separated by air gaps. The fibers (20) are oriented in the direction to perpendicular to the collector (5) collecting elements (52). After laying the fiber (20) layer onto the surface of the collector (5) collecting elements (52), the fiber layer is brought by the movement of the collector (5) to a receiver (70) comprising two oppositely movable cutting parts (71, 72) with ground edges (710, 720) wherein the cutting parts (71, 72) cut the fiber layer, in the area between the adjacent collecting elements (52), in at least one portion of a predetermined size and shape, which is then received in one cutting part (71, 72) of the receiver (70). The invention also relates to a device (1) for producing a fiber layer (20) and a collector (5) for laying fibers (20).

Description

Method and apparatus for producing a layer of fibers, in particular nanofibres, microfibres or mixtures thereof, with fibers oriented in one direction, and a collector of this fiber storage device

Technical field

The invention relates to a method for producing a layer of fibers, in particular nanofibres, microfibers or mixtures thereof, with fibers oriented in one direction.

The invention also relates to a device for producing a layer of fibers, in particular nanofibres, microfibres or mixtures thereof, with fibers oriented in one direction, and to a collector of this fiber storage device.

BACKGROUND OF THE INVENTION

To date, a number of methods have been proposed for producing microfibers (fibers with a diameter above one micrometer) and nanofibres (fibers with a diameter of up to one micrometer) or mixtures thereof based on various physical or chemical principles. These include, for example, 'forcespinning' and 'rotary jet spinning', 'island-in-a-sea', 'meltblowing' and 'gas jet spinning' ), etc. On an industrial scale, the so-called electrostatic spinning described, for example, in US 2,048,651, in which the fibers, especially nanofibers, are prepared by force action of a high intensity electric field formed between at least one spinning electrode and at least one a collecting electrode, which may optionally also be supported by the action of an air or gas stream on the liquid solution or polymer melt. At the same time, the fibers thus formed are carried by the force of the electric field and / or the air flow towards the collecting electrode and are deposited either directly on the collecting electrode surface, in the space between its elements or on the surface in front of it or next to it. During its development and movement in the electrostatic field, the fiber undergoes many morphological changes that cause its gradual narrowing, in combination with other influences also changes in its movement, which is, as a result, chaotic. If no action is taken, there is no way to estimate in advance the point of impact, the angle of incidence, or the shape the fiber will assume upon impact on the collecting electrode or substrate. Thus, an unordered layer of corrugated fibers of different diameters and lengths deposited in random directions with numerous kinks is typically formed on the collecting electrode or substrate.

Different types of spinning electrodes are used in electrostatic spinning, the best known and easiest being a single nozzle or a group of nozzles arranged in a suitable whole - for example a line, surface or circle, etc. In some variations, the nozzle / nozzles are coaxial so that hollow or bicomponent fibers. For industrial applications, however, due to the considerably higher power and reliability, jet-free or so-called surface spinning electrodes formed eg by a slit - see eg US 2012/0 013 047, or more often by a wetted polymer or molten body such as a cylinder - see CZ 274 294 or analogous WO 2005/024 101, roller with darkness or projections - see CZ 2005-360 or analogous WO 2006/131 081, static or movable in its direction - see CZ 2007-485 or analogous WO 2009/010 020, or a string moving along a circular path - see CZ 2009-525 or an analogous WO 2011/015 161, etc.

A number of different collection electrode variants are used in combination with these spinning electrodes. The simplest of these is a rectangular, square or circular plate made of electrically conductive material, eg stainless steel, a collecting electrode consisting of a rod or a set of rods or strips, or a cylindrical collecting electrode - see CZ 2006-477 or an analogous WO 2008/011

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840, the design of which prevents the concentration of electric charges and the formation of electric corona discharges.

To form layers of fibers oriented in one direction, respectively. in order to influence the direction and method of deposition of individual fibers, several variants of split static collecting electrodes have been proposed, which comprise electrically conductive elements arranged in parallel, such as wires, strips or slats, separated by an air gap or electrically non-conductive material, the electrodes are in the form of a plate of electrically non-conductive material with applied strips of electrically conductive material or vice versa the plates of electrically conductive material are covered by suitably selected surfaces of electrically non-conductive material, etc. - see eg US 2008122142. based on the phenomenon described in Dan Li, Yuliang Wang, and Younan Xia: "Electrospinning of Polymeric and Ceramic Nanofibers as Uniaxially Aligned Arrays", ΝΟΑΝΟ LETERS 2003, Vol. 3, No. 8, pp. 1167-1171, in which the individual electrically charged fibers deposit alternately on their opposite ends or different sections on two separate electrically conductive elements, due to electrical interactions in the electric field, forming a layer with a predominant orientation in one direction in the gap between them . Rotary split collecting electrodes have also been proposed on the same principle, where the orientation of the deposited fibers is further aided by the rotation of the collecting electrode - see, for example, P. Katta, M. Allessandro, R. D. Ramsier, and G.G. Chase: “Continuous Electrospinning of Aligned Polymer Nanofibers on a Wire Drum Collector”, ΝΟΑΝΟ LETTERS 2004, Vol. 11, pp. 2215-2218. The disadvantage of these variants is that, due to the deposit of the fiber layer on the surface of the collecting electrode, all or a substantial part of the collecting electrode does not allow removal of the layer without mechanical damage.

This disadvantage is partially solved by a collecting electrode, which is formed by an endless belt with regularly arranged electrically conductive wire-shaped elements separated by a free gap - see for example WO 2008/062 264, in which a substantial part of the fiber layer is loosely deposited between adjacent wires. However, this document does not address in any way the sensing of the fiber layers or the method of placing the wires on the support strips, which would allow rotation and relative displacement of each of them when passing over the guide rollers.

Another type of collecting electrode, which should lead to the orientation of fibers of the formed fiber layer in one direction, then the body (eg rod, cylinder or strip) provided with different protrusions, most often spikes on which the electric field is concentrated - see CZ 2007-727 or analogous WO 2009/049 564. Due to the point-to-point contact of the formed fiber layer and the collecting electrode surface and hence due to the relatively low adhesion therebetween, this solution permits continuous removal of the fiber layer with only minimal damage. Its drawbacks are that in practice, this electrode spinning effect is low due to the concentration of the electric field to a few points, and that even the small mechanical damage to the fiber layer that occurs during its removal from the spikes is applications (especially medicine, tissue engineering, filtration, etc.) unacceptable.

In all publications published so far, the almost neglected problem is the method of detecting the layers of fibers deposited on the collecting electrodes or the underlying material, and their subsequent folding into more complex three-dimensional structures. However, this part is very crucial. It is quite complicated to produce a sufficiently thick layer of nanofibres or microfibres or mixtures thereof oriented in one direction without stacking more layers on top of each other. With longer deposition of the fibers on the electrically conductive elements of the divided collecting electrode, an insulating barrier gradually forms in the electrostatic field. Paradoxically, this barrier is represented by the very layer of fibers applied to the electrically conductive elements. In addition, electrostatic force interactions occur between the already applied fibers and the newly applied fibers. These newly deposited fibers then lose their tendency to orient themselves in a direction perpendicular to the electrically conductive elements of the collecting electrode, and they are only oriented by mechanical forces due to rotation or other movement of the collecting electrode. Overall, the degree of fiber orientation is thus gradually reduced. However, the formation of thicker layers of oriented microfibers or nanofibres or mixtures thereof and spatial structures composed of these oriented fibers is very important for many fields, such as optics, micro-electronics, and medicine. In particular, in tissue engineering, they can play an important role in the development of scaffolds - the basis for cell growth, and biological replacements in the implantation of tissues or organs - and are also beginning to be used in the recovery of muscle and bone cells. Nanofibrous materials in general, whether composed of oriented or non-oriented nanofibers, are beginning to play a key role in injury and burn centers in skin repair and wound healing, preventing special micro-organisms from penetrating the wound and their large specific surface and porosity. efficiently and significantly better than conventional materials to control water and heat dissipation. When they heal wounds, they create a physical barrier to impurities, but allow moisture to penetrate and oxygenate. In the case of nanofibrous materials composed eg of layers of spun hyaluronic acid, the nanofiber material itself contributes to the treatment or regeneration. In addition, for example, US 2008/0 208 358 discloses a scaffold composed of several layers of oriented nanofibres of synthetic polymer interspersed with a layer of hydrogels 50 to 250 microns thick. However, the need for new materials with a precise internal structure is required not only in medicine, but also in many other applications, such as the development of plant explants, etc.

It is known from many publications and patents to create spatial structures from oriented fiber layers, which either takes place while maintaining the fiber orientation in all layers, or the fiber orientation of the individual layers is different. Most often it is a folding of layers with 90 ° rotation in dry layers to odd ones, ie alternately perpendicular to each other (see eg US2007 / 0 269 481 - specifically Fig. 38, or US 2011/0 166 647 - see specifically Fig. 10) . However, these works lack information on how fiber layers are handled, as well as practical and industrially applicable layering solutions. In all cases, this is only a laboratory process with laboratory aids which, due to the high demands and / or low efficiency, is completely unsuitable for industrial use.

In view of the above, it is an object of the present invention to provide a method for producing a layer of oriented fibers (nanofibers, microfibers or mixtures thereof) which would make it possible to remove the formed layer from the collecting electrode as easily as possible while achieving sufficient power for industrial use.

It is also an object of the present invention to provide a method for sensing and subsequently folding layers of oriented fibers into a layer of desired thickness, as well as an apparatus for carrying out the method, and a fiber collector for the apparatus.

SUMMARY OF THE INVENTION

The object of the invention is achieved by a method for producing a layer of fibers, in particular nanofibres, microfibers or mixtures thereof, with fibers oriented in one direction, in which the fibers are formed by electrostatically spinning a polymer solution or melt in an electric field formed between at least one spinning electrode and at least one collecting electrode. and deposited in a layer on the collector collector surface enclosed in an infinite loop, separated by air gaps, the fibers oriented in a direction perpendicular to the collector collector, the principle being that after depositing the fiber layer on the collector collector surface this layer, by moving the collector, leads to a collector comprising two oppositely movable shear pieces of which at least one is provided with ground flanges / edges. The latter then cuts at least one part of a predetermined size and shape in the space between adjacent collecting elements, which is stored in one shear part of the collector.

Advantageously, the cut-off portion of the layer is such that the first shear portion of the collector is first brought into contact with the fiber layer, which is lightened, and then the second shear portion of the collector is pressed against it to cut out a portion thereof. This part is then removed from the part by the flow of air from one of the header shear pieces and deposited on the bottom of the other header shear piece.

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Due to the fact that the fiber layer comes into contact with the collector only for a very short period of time and only at its cutting edges, it does not suffer mechanical damage and retains its initial structure and properties even after removal from the collector.

In order to create a spatial formation with different fiber orientations in its structure, after the portion of the fiber layer has been cut, the collector is rotated through an angle of 0 to 180 ° so that the subsequently cut portion of the fiber layer has a different fiber direction.

The cut pieces of the fiber layer with the desired orientation are then deposited at the bottom of one shear part of the collector and after reaching the desired thickness and / or number of parts are transferred from this part by moving its bottom to another handling element or substrate.

According to the design of the collector and the arrangement of the collector collector elements, one part or at least two parts side by side are cut from the fiber layer deposited on the two collector elements, or at least two parts are cut from one gap between two adjacent collector collector elements. / or at least part of at least two gaps between collector collector elements.

In two basic variations, the collector header elements may be formed of an electrically conductive material, at least some of which are high voltage applied, so that they serve or contribute to the formation of an electric field in which electrostatic spinning takes place, thereby forming the collector electrode or on the contrary, they are made of an electrically non-conductive material and / or no electrical voltage is applied to them, so that they merely mechanically retain the fibers.

At least two types of fibers differing in diameter and / or length and / or material and / or basis weight and / or the content of impurities / impurities in the fiber material are deposited on the collector collector elements in order to achieve the desired structure of the resulting material, either stacked, or separately side by side.

In this case, the collector moves either uniformly or stepwise and / or reciprocally, or does not move, when the fibers are being applied, before the parts are removed.

In order to avoid disturbing the remainder of the previously removed layer when applying a further fiber layer, it is desirable to remove the remainder of the layer after collecting a predetermined number of portions of the previous fiber layer from the collector collectors. For example, an air jet, a mechanical element or a cleaning solution can be used for this purpose.

The object of the invention is also achieved by a device for producing a layer of fibers, in particular nanofibres, microfibers or mixtures thereof, with fibers oriented in one direction, by electrostatic spinning of a polymer solution or melt in an electric field formed between at least one spinning electrode and at least one collecting electrode. a movable collector enclosed in an endless loop which extends into this electric field and which is guided on at least two guide elements, of which at least one is collided with a drive for rotary movement, characterized in that the collector comprises collecting elements separated by air gaps wherein a collector is provided on its path comprising two shear pieces displaceable relative to each other, at least one of which is provided on the facing surface with ground flanges / edges arranged in a desired shape, the dimensions of which are equal or smaller than the dimensions of the gaps between two adjacent collecting members collector. In addition, the two pantograph parts are provided with a perforated bottom, the bottom of one of which is movable in a direction perpendicular to its plane and serves to transfer the deposited fiber layer (s) to another handling element or substrate.

In one embodiment variant, the collector resp. its collecting elements contribute to the generation of the electric field in which electrostatic spinning takes place, these elements being formed of an electrically conductive material and connected to the opposite pole of a high DC voltage source than the spinning electrode (s).

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In the second variant, on the other hand, they are made of an electrically non-conductive material.

In addition, the object of the invention is also achieved by a collector of this device, which comprises parallel arranged collecting elements separated by air gaps placed between two belts closed in an endless loop and guided over at least two guide elements. The pairs are connected by connecting parts to the grippers, which are connected to the quartz in one place with the possibility of rotation and in the other place with the possibility of rotation and displacement. Preferably, the bearing is formed so that at least two collecting members of each gripper pass through its fasteners and their ends engage in holes in the facing faces of the fastening clips mounted on the belt surface, both ends of one collecting element engaging in a circular hole formed in the facing faces the coupling clips and both ends of the second collecting member engage a groove formed in the facing faces of the other coupling clips.

If desired, the collecting elements are formed of an electrically conductive material and possibly all electrically conductive interconnected or, on the contrary, formed of an electrically non-conductive material.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1a shows schematically a device for producing a layer of fibers with fibers oriented in one direction according to the invention in one embodiment, in Fig. 1b this device in another embodiment, Fig. 2 a preferred variant of a collector of this storage device Fig. 3 shows a clip for connecting the carrier to the belts of the collector for storing fibers for the collector variant according to Fig. 2, or Fig. 4 another embodiment of the collector of the device according to the invention 5b shows a cross-section through this collector, FIG. 6 shows one variant of the shearing process of the square sections of the fiber layer, and FIG. 7 shows a variant of the shearing process of the hexagonal sections of the fiber layer.

DETAILED DESCRIPTION OF THE INVENTION

The principle of the invention will be explained on an exemplary embodiment of a device for producing fibers (nanofibres, microfibres or mixtures thereof) according to the invention, the two basic variants of which are schematically shown in Figures 1a and 1b, and their function.

In the variant shown in FIG. 1a, the device 1 comprises a spinning electrode 2 and a collecting electrode 3 arranged opposite it, which are connected to the opposite poles of a high-voltage direct current source 4 or one of them is grounded. (i.e., without applied electrical voltage and / or electrically non-conductive material), a movable fiber storage collector 5. The collector 5 (FIG. 2) comprises, in a preferred embodiment, two belts 51 of electrically nonconductive material enclosed in an endless loop and guided on two parallel pairs of rotatably mounted pulleys 510 of which at least one pair is coupled to a rotational movement drive (not shown). This movement may be uniformly intermittent and / or reversible, or any other as desired. The pulleys 510 of each pair are interconnected by a shaft 511, thereby synchronizing their movement and also the two belts 51 guided thereto. The belts 51 are then connected by collecting elements 52 situated between the belts 51 and formed by the same parallel wires of electrically conductive material. they are arranged within the collector 5 according to need, but preferably evenly - i.e. with the same pitch or spacing. air gap. In the illustrated embodiment, the collecting elements 52 are arranged in pairs of different spacing between the collecting elements 52 arranged in pairs of different spacing between the collecting elements 52 of one pair and the collecting elements 52 of adjacent pairs.

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Any spinning electrode 2 consisting of a nozzle (capillary), a set of nozzles (capillaries) arranged in a desired shape, or any nozzle or capillary nozzle can be used as the spinning electrode 2, which is generally shown as a nozzle in the embodiment of Figs. . a surface spinning electrode formed by, for example, a slit or body wetted in a polymer solution or melt, such as a cylinder, a cylinder with darkness or projections, a static or movable string, a circular path, etc., or a combination electrodes of the same or different types. The collecting electrode 3 (s) may then be any known collecting electrode 3 formed, for example, by a plate of electrically conductive material, a rod or set of rods or strips, or a cylindrical collecting electrode, or a combination of several collecting electrodes 3 of the same or different types.

In the electrospinning process occurring in the electric field formed between the spinning electrode 2 and the collecting electrode 3, the formed fibers 20 move towards the collecting electrode 3, catching on the collecting elements 52 of the collector 5 and, in particular, overlapping the gaps between them and they are oriented in a direction perpendicular to them, respectively. in the direction of collector movement 5.

In the variant of the device 1 according to the invention shown in Fig. 1b, the collector 5 simultaneously serves as a collecting electrode 2. Its construction is the same as in the variant described above, with the difference that its collecting elements 52 made of electrically conductive material are connected to the opposite pole of the source 4 of a high DC voltage than the spinning electrode 2, or are grounded in a variant (not shown). Thus, the electric field in which the fibers 20 are formed is formed between the spinning electrode 2 and the collectors 5 of the collector 5, while the fibers 20 are captured on these collectors 52 as they move and again overlap the air gap therebetween and perpendicular to them, respectively. However, their orientation is determined not only by the movement of the collector 5, but in particular by the electrical conditions in the vicinity of its collecting elements 52 and by the electrical interactions that occur when the electric beverage 20 is combined with the electric charge of the collecting elements 52 of the collector 5. the first end or section of said fiber 20 to one of them.

For modification, respectively. adjusting and / or increasing the intensity of the electric field (s) formed between the spinning electrode 2 (s) and the collector elements 52 of the collector 5, in an illustrative embodiment (not shown), at least one collecting electrode 3 connected to the collector 5 the same pole of the high-voltage direct-current source 4 with which the collector elements 52 of the collector 5 are connected, or the pole of another high-voltage direct-current source (not shown) with the same polarity but different voltage.

In both variants, the fibers 20 are deposited on the collector 5, respectively. its collecting elements 52, during its movement, and in the second variant even at the moment when the collector 5 does not move, resp. stand, using its area in parts.

FIG. 2 shows schematically the most suitable variant of the collector 5 in which its collecting elements 52 are supported on belts 51 parallel to the axis of rotation of the guide pulleys 510 by means of carriers 520. Each carrier 520 is formed by a pair of identical parallel collecting elements 52 which are connected at their ends by connecting parts 521 arranged parallel to the belts 51 and which are connected at two points near their ends or directly through the through collecting elements 52 to the quartz 51 with the possibility of rotation or rotation. rotation and possibly shift. In this manner of mounting, the fixed distance between the collecting elements 52 of each carrier 520 is constantly defined and ensured throughout the movement of the collector 5, since when passing over the pulleys 510, only the adjacent carriers 520 as a whole rotate and / or shift. The grippers 520 need not be disposed immediately after the periphery of the collector 5, as in the variants shown in FIGS. 2 and 4, but may be discrete, spaced apart. This

The variant is particularly suitable for the use of the collector surface 5 in parts, where the spinning process takes place only at the carrier 520 when the collector 5 is not moving.

From the point of view of guiding the belts 51, a variant is particularly advantageous in which the belts 51 consist of polyurethane synchronizing self-centering toothed belts with an aramid cord. By using these or other similar belts 51, it is possible to provide power to the collecting elements 52 and 52, respectively. their connection to a source 4 of high DC voltage, for example by EFT technology, when in the production of toothed belts some of their teeth are formed from electrically conductive material, eg from aluminum alloy EN AW-7075. These teeth then come into contact with the pulleys 510 connected to the high-voltage source 4 during movement, thereby transferring the respective electrical voltage to the collecting elements 52 or the carriers 520. In this case, however, it is preferable to feed only a portion of the collecting elements 52 in the vicinity of the pulleys 510 where electrostatic spinning takes place. If necessary, however, it is possible to interconnect all the collector elements 52 of the collector 5 interconnectively. In addition to the electrically conductive teeth of the belts 51, the collector 5 collector 5 can be supplied with other means, such as an additional supply wheel or rim, to any point of the collector 5 as needed.

In other variants (not shown), the carriers 520 may be formed, respectively. may comprise more than two collecting elements 52 as desired, and all collecting elements 52 may be supported within the carrier 520 with the same or different air gap.

Preferably, a clip 53 is used to attach the collecting members 52 to the belts 51 (FIG. 3). In this case, it has a circular hole 530 formed in one of its front faces, the diameter of which corresponds to the collector 5 of the collector 5, and a groove 531 in the other face, whose height corresponds to the diameter of the collector 52. 51, alternately, so that when viewed from one side 53, a circular hole 530 and a groove 531 are visible in each clip 531. Each carrier 520 is then on one side one of its collecting element 52 which extends over its connecting pieces 521 and extends into the circular hole 530, connected by means of two clips 53 to the two rotatable belts 51 and, on the other hand, by its second collecting element 52, which passes through its connecting parts 521 and extends into the groove 531, connected by other two clips 53 to both belts 51s the possibility of rotation and at the same time the displacement in the direction of the tangent to the dan line point of bearing and center of rotation (pulley 510). It will be appreciated that two types of clips 53 can be used in a variant (not shown), wherein clips 53 of one type have only circular holes 530 on their faces and clips of the other type only grooves 531. In another variant not shown, the carriers 520 can be attached to belts 51 directly through their connecting parts 521, so that their collecting members 52 need not be spaced in multiples of the spacing elements of the belts 51. The pulling clips 53 conductively interconnect the belt teeth 51 formed of the electrically conductive material with the collecting members 52 of the collector 5.

In a variant (not shown), the connection of the grippers 520 to the belts 51 is designed in opposite construction - the connecting clips 53 have darkness formed on their faces which engage holes and grooves in the lateral sides of the grippers 520, e.g. on the surface of the belts 51 for attaching the collecting elements 52 and / or the carriers 520 to form or receive other suitable shaped projections provided with an opening or groove or mandrel.

Due to the movement of the grippers 520, it is preferable that they are attached to the belts 51 near the ends of the fasteners 521, e.g. via their extreme collecting members 52, but in the case where the gripper 520 comprises more than two collecting members 52 connected via any two of them.

In other embodiments (not shown), chains may be used instead of belts 51. In this case, when the collectors 52 are mounted at the chain link pins and hence at the pitch circle pitch of the guide sprockets, there is only minimal variation in the distance of the individual collectors 52, which in addition is compensated by their radius. For example, at average

50046, the trajectory over which the collecting members 52 move is very smooth, and their relative rotation is small and the relative elongations / shortening of the fiber layer 20 deposited on the collecting members 52 is minimal. If the collector 5, respectively. its collecting elements 52 at the same time as the collecting electrode 2, it is advantageous to use a roller chain with threaded pins on one side. The collecting elements 52 are then connected to these pins via insulators 6 and their power is provided by a power ring / rims attached / attached to additional disks 61 of electrically non-conductive material (e.g. polyethylene) that insulate the guide sprockets 50 from the inside (Fig. 4).

In addition to the above described, in other variants (not shown) the collector elements 52 of the collector 5 may be formed and / or arranged as desired, for example they may consist of slats, prisms, rods, and / or have different diameters and / or different materials or they are arranged unevenly within the collector 5, eg to increase or decrease the density of the deposited fibers 20 in certain sections, etc. In addition, they may be mounted on the belts 51 / chains so that they grip the pulleys 510 / sprockets 50 any angle other than 90 ° formed at the illustrated embodiments. In addition to being guided through two pairs of pulleys 510 or sprockets 50, the collector 5 may be guided over at least two guide elements, e.g., parallel guide rollers. However, two pairs of pulleys 510 / sprockets 50 are particularly advantageous in terms of the possibility of installing the collecting electrode 3 (s) or other devices in the space therebetween and also in terms of the movement of the collector 5 therethrough. In addition, the collector 5 can be supported or tensioned on its track by not shown tensioning pulleys / sprockets and / or guide rollers / guide rails, and the like.

In various embodiments of the device according to the invention, several identical combinations of the spinning electrodes 2 and the collecting electrodes 3, or conversely different combinations with different types of the spinning electrodes 2 and / or collecting electrodes 3 for forming multiple layers of fibers, 20 and stacking or forming fibers 20 of different materials and / or with different diameters and / or lengths and / or basis weights, optionally other parameters and / or containing appropriate additive (s) in the fiber material, etc. In addition, for example in the sense of CZ 302 901 or an analogous EP 2 530 189, particles of at least one suitable substance which modifies the properties of the fibers 20 and / or on the individual layers of the fibers 20 may be introduced between them and / or separately. or gives them new properties, which particles can be clogged et particularly in liquid and / or solid state.

Typical spinning upwards in which the collecting electrode 3 is arranged above the spinning electrode 2 shown in a variant of the device 1 according to the invention in Figs. 1a and 1b can be replaced or supplemented by the spinning electrode 2 (electrodes) and collecting electrode 3 (electrodes). downward spinning, lateral spinning, slanted sideways spinning, etc. The spinning process is preferably carried out at the pulley 510 / sprocket 50 where the carriers 520 are most distant from each other since the fibers 20 are approached in the straight part of the collector 5. located at the point of a narrow gap between their adjacent collecting elements 52 is compressed. Otherwise, pulling over the pulleys 510 / sprockets 50 would be tensile and tear due to their small length and great elongation.

The device 1 according to the invention can be oriented vertically as shown in its variants in Figs. 1a and 1b, optionally horizontally or substantially at any incline, or its collector 5 can be guided on several pulleys 510 / sprockets 50 / guide rollers in any shape / length.

In the above-described manner, at least one layer of fibers 20 (nanofibers, microfibers or mixtures thereof), the fibers 20 of which are oriented in the direction of movement of the collector 5, is deposited on the outer surface of the collector elements 52.

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The removal of this fiber layer 20 from the collector 5 is then effected by cutting their portions at the air gap between two adjacent collecting elements 52 of one carrier 520 by means of a collector 70 which is part of the collecting module 7, one variant of which is shown in FIG. then in FIG. 5b. This particular type of collector 70 is formed with a square base and is thus intended to cut out the square portions of the fiber layer 20, but in other embodiments (not shown) it may have virtually any meaningful and structurally solvable shape. The header 70 comprises an upper shear member 71 and a lower shear member 72, which are displaceable relative to each other in the vertical direction (arrow A) and preferably also rotatable about their vertical axis (arrow B) in the arms (not shown) of the collector module 7. The two shear pieces 71, 72 are provided with precisely ground sides / blades 710, 720 arranged in a square and guided through the darkness 71, 721 so that the ground sides / blades 710 of the upper part 71 fit precisely into the ground sides / blades 720 of the lower part 72, respectively. on the contrary, so that, in cooperation, they are able to cut a portion of the desired shape from the fiber layer 20. Both shearing parts 71, 72 are simultaneously provided with a perforated bottom 712, 722. Moreover, the bottom 722 of the lower shearing part 72 is movable in a direction perpendicular to its plane (in the variant variant in the vertical direction) and serves as a so-called ejector. a portion (s) of the fiber layer 20 to a destination, eg, a finalization module 8, where further manipulation and / or processing and / or treatment takes place. Preferably, in addition to moving the bottom 722 of the shear portion 72 of the header 70, an air stream is also used to remove the fiber layer portion (s). In a variant of the embodiment (not shown), the grinded flanks 710, 720 of the parts 71, 72 of the collector 70 are arranged to cut two or more portions of the fiber layer 20 side by side, in one or more air gaps between the collector elements. 52, or at least two collectors 70 are arranged side by side and / or one behind the other.

In other variants of the collector 5 not shown (not shown), the elements 71, 72 of the collector 70 may be arranged horizontally or obliquely, any of which may be used to receive at least one cut-out portion of the fiber layer.

Collector 70, resp. its shear members 71, 72 are formed at a width corresponding to the distance between the belts 51 / of the collector 5 chains and / or are movable in a direction parallel to the axes of the collector 5 collector members 52 so that it is able to cut individual portions of the fiber layer 20 side by side.

In a variant of the embodiment (not shown), the collector 70 is formed such that only one of its parts 71, 72, preferably the lower part 72, is provided with a ground side / blade 710, 720 and its second part is provided with a suitable flat or shaped surface.

During spinning as the collector 5 moves, the two shear portions 71, 72 of the header 70 are inserted into the arms which are slightly open so that the header 70 does not form a barrier to the flow of air. When shearing and removing the fiber layer 20, both arms are then brought closer and the upper shear member 71 and the lower shear member 72 of the collector 70 are moved near the collector 5 and the collector 5, respectively. The lower shear portion 71 first extends into contact with the fiber layer 20 and lifts it slightly, then by sliding the upper portion 72 out of the arm to cut the layer and press the cut portion toward the bottom 722 of the lower shear In this synchronized movement, just after cutting the fiber layer 20, filtered air is released from the top panel 71 to the bottom panel 72 through their perforated bottoms 712, 722. By its dynamic action, the fiber layer 20 is removed from the upper shear portion 71 of the collector 70 and 70, respectively. In other variations, the movement of a non-illustrated mechanical element (s) disposed in or on such a part 71 may be used to remove the fiber layer 20 from the upper part 71 of the collector 70, such as after the first portion of the fiber layer 20 has been cut, the collector 70 can be rotated by 0 to 180 ° as desired, for example by 90 °, as shown in the collector module arm 7, so that the layer portion subsequently cut and deposited The fibers 20, if desired, have fibers 20 oriented in a different direction (FIG. 6) than the previous section. These portions of the fiber layer 20 are cut out successively side by side from the fiber layer 20 between two collecting elements 52 or successively between different

In this way, spatial formations of any overall thickness with arbitrary fiber orientation can be formed from the fiber layers 20, and with the appropriate shape of the collector parts 70 and 70, respectively. arrangement of their cutting edges, as well as layers of any shape. FIG. 7 illustrates, by way of illustration, the steps of successively cutting the layers of hexagonal fiber 20 and depositing them with the fiber orientation of the layers rotated 60 ° relative to each other while cutting successively side by side from the fiber layer 20 between two collecting elements 52.

In other embodiments of the header 7, the top member 72 and the bottom member 71 operate in opposite directions to those described above.

In the event that the collector elements 52 of the collector 5 form an angle other than 90 ° to the belt / chain axes, the entire shear module 7 and / or its collector 70 can be arranged or assembled at an angle of 90 °. rotate or shape-shaped according to the arrangement of the collecting elements 52 to cut a portion (s) of the fiber layer 20 with the desired fiber orientation 20.

After each removal of a portion of the fiber layer 20 or the removal of the required number of portions of the fiber layers 20 and formation of the spatial fibrous structure in the lower shear member 72 of the collector 70, this material is passed to the finalization module 8 (FIGS. the bottom 722 to remove it from the collector 70 and the collector 70, respectively. its lower part 72 and its placement on a suitable substrate or other handling element and for further processing thereof. The removal of the fiber layers 20 by the collector (or 70) located in the shear collector module 7 and the passing of the collector (s) 70 to the finalization module 8 is repeated as required and as long as the applicable fiber layers 20 are available on the collector 5. the collector 70 could cut portions of the fiber layer 20 from its entire circumference.

The whole process is terminated by cleaning the collector 5 of collector 5 in the cleaning module 9, which is preferably situated on the opposite branch of the collector 5 than the shear module 7. For example, an air stream is used to clean the fibers. This may be a pre-heated air stream. Further, or in other variations, suitably shaped element (s) such as a brush (s) that move over their surface and / or a cleaning solution are used to clean the collector elements 52 of the collector 5. In the latter variant, it is advantageous if the collecting elements 52 are dried before applying further fibers 20.

The whole device 1 is preferably divided by at least one partition 10 into a part 11 where the spinning process takes place and a part 12 where the layer (s) of fibers 20 are taken and optionally further processed. This division has not only a safety but also a technological function - there is no influence of elements in individual parts, especially the electric field created between the spinning electrode 2 (electrodes) and the collecting electrode 3 (electrodes), eventually fouling of the fiber layer fragments into the spinning space, etc.

Claims (22)

PATENT CLAIMS Method for producing a layer of fibers (20), in particular nanofibres, microfibres or mixtures thereof, with fibers (20) oriented in one direction, in which the fibers (20) are formed by electrostatically spinning a polymer solution or melt in an electric field formed between at least one by a spinning electrode (2) and at least one collecting electrode (3) and deposited in a layer on the surface of the collecting elements (52) of the collector (5) enclosed in an endless loop, separated by air gaps, these fibers (20) oriented in the direction perpendicular to the collector elements (52) of the collector (5), characterized in that after depositing a layer of fibers (20) on the surface of the collector elements (52) of the collector (5), this layer is brought to the collector by moving the collector (5). a ratchet (70) comprising two oppositely movable shear pieces (71, 72), at least one of which is provided with ground flanks / edges (710, 720), which ken (20) in the space between the adjacent head element (52) is cut out at least one portion corresponding in shape and size to a shear element (71, 72), which is stored in one shear member (71, 72) of the collector (70). Method according to claim 1, characterized in that the first shear part (71, 72) of the collector (70) is first brought into contact with the fiber layer (20) which it relieves, and then a second shear part (71, 72) is applied thereto. ) of the collector (70) is pushed from the opposite side, thereby cutting out a part thereof, which is then removed from the shear part (71, 72) by a stream of air from the shear part (70) and deposited on the bottom (712, 722) the shearing part (71, 72) of the header (70). Method according to claim 1 or 2, characterized in that the punching of a portion of the fiber layer (20) is rotated by an angle of 0 to 180 ° so that the fibers (20) of the subsequently cut portion of the fiber layer (20) are relative to the fibers. (20) previously cut out portions of the fiber layer (20) oriented in a different direction. Method according to any one of the preceding claims, characterized in that the cut out portions of the fiber layer (20) are deposited on the bottom (712, 722) of one shear part (71, 72) of the collector (70) until the desired thickness and / or the number of portions of the fiber layer (20), and thereafter transferred therefrom by moving its bottom (712, 722) to the handling element or substrate. Method according to any one of claims 1 to 4, characterized in that the fiber layers (20) deposited on the two collecting elements (52) are cut out one part in the space between the collecting elements (52). Method according to any one of Claims 1 to 4, characterized in that at least two parts are successively cut out side by side from the fiber layer (20) deposited on the two collecting elements (52) in the space between the collecting elements (52). Method according to any one of the preceding claims, characterized in that at least two portions of the fiber layer (20) are cut out of the space between two adjacent collecting elements during one stroke of the collector (70) from the fiber layer (20) deposited on the collecting elements (52). the elements (52) of the collector (5) and / or cut out at least one part of the fiber layer (20) from at least two spaces between the collector elements (52) of the collector (5). Method according to any one of the preceding claims, characterized in that the collector elements (52) of the collector (5) are made of an electrically conductive material and at least some of them are supplied with high voltage so that they serve or contribute to the generation of the electric field. in which electrostatic spinning takes place, thus forming a collecting electrode (3). Method according to any one of claims 1 to 7, characterized in that the collector elements (52) of the collector (5) are made of an electrically non-conductive material and / or no electrical voltage is applied to them. Method according to any one of the preceding claims, characterized in that at least two types of fibers differing in diameter and / or length and / or material and / or basis weight and / or basis weight are deposited on the collector elements (52) of the collector (5). or the admixture (s) in the fiber material (20). Method according to any one of the preceding claims, characterized in that at least two types of fibers (20) differing in diameter and / or length and / or material and / or basis weight are separately deposited on the collector elements (52) of the collector (5). and / or the admixture (s) in the fiber material (20). -11 GB 304660 B6 Method according to any one of the preceding claims, characterized in that the collector (5) moves uniformly or stepwise and / or reciprocally when applying the fibers (20), prior to detecting parts of the fiber layer (20). Method according to any one of the preceding claims, characterized in that the collector (5) does not move during the application of the fibers (20), prior to detecting parts of the fiber layer (20). Method according to any one of the preceding claims, characterized in that after removal of the fiber layer portion (s) (20), the remainder of the fiber layer (20) is removed from the collector collector elements (52) and removed therefrom. (20) remained, by air flow, mechanical element or cleaning solution. Apparatus (1) for producing a layer of fibers (20), in particular nanofibres, microfibers or mixtures thereof, with fibers oriented in one direction, by electrostatic spinning of a polymer solution or melt in an electric field formed between at least one spinning electrode (2) and at least once a collecting electrode (3) comprising a movable collector (5) enclosed in an endless loop that extends into this electric field and which is guided on at least two guide elements, at least one of which is coupled to a drive for rotary movement, characterized by The collector (5) comprises collecting elements (52) separated by air gaps, and on its path a collector (70) is provided, which comprises two shear parts (71, 72) displaceable relative to each other, at least one of which is on the facing the surface is provided with ground flanks / blades (710, 720) arranged in a shape whose dimensions are equal or smaller larger than the gap dimensions between two adjacent collector elements (52) of the collector (5), wherein the ground flanks / blades (710, 720) of one shear portion (71, 72) of the header (70) fit into the ground flanks / blades (710, 720) the second shear member (71, 72) of the header (70), and the two shear members (71, 72) of the header (70) are provided with a perforated bottom (712, 722), the bottom (712, 722) of one shear member (71, 72 ) is movable in a direction perpendicular to the plane of the bottom (712, 722). Apparatus (1) according to claim 15, characterized in that the collector elements (52) of the collector (5) are formed of an electrically conductive material and at least some of them are connected to the opposite pole of the source (5). 4) a high DC voltage than the spinning electrode (s) (2). Device (1) according to claim 15, characterized in that the collector elements (52) of the collector (5) are made of an electrically non-conductive material. A collector (5) of a device (1) for producing a layer of fibers (20), in particular nanofibres, microfibers or mixtures thereof, with fibers oriented in one direction, comprising parallel collecting elements (52) arranged parallel to each other separated by air gaps between belts (51) closed in an endless loop and guided over at least two guide elements, characterized in that the collecting elements (52) are connected at least in pairs by connecting parts (521) to the grippers (520) which are connected to the quartz (51) in one place with the possibility of turning and in the other place with the possibility of turning and shifting. Collector (5) according to claim 18, characterized in that two collecting elements (52) of each carrier (520) pass through the connecting parts (521) of the carrier (520), the two ends of one collecting element (52) extending into circular holes (530) formed in the facing faces of the coupling clips (53) and both ends of the second collector element (52) engage grooves (531) formed in the facing faces of the other coupling clips (53). Collector (5) according to any one of the preceding claims, characterized in that the collecting elements (52) are formed of an electrically conductive material. Collector (5) according to claim 20, characterized in that all the collecting elements (52) are electrically conductively connected. - 12GB 304660 B6 A collector (5) according to any one of the preceding claims, characterized in that the collecting elements (52) are formed of an electrically non-conductive material.