Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/0007—Electro-spinning
  • D01D5/0061—Electro-spinning characterised by the electro-spinning apparatus
  • D01D5/0076—Electro-spinning characterised by the electro-spinning apparatus characterised by the collecting device, e.g. drum, wheel, endless belt, plate or grid
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/0007—Electro-spinning
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D7/00—Collecting the newly-spun products

Definitions

• the present invention relates to a method for production of two-dimensional or three- dimensional fibrous materials of microfibres or nanofibres in which at first nanofiber or microfiber is continuously drawn out of a solution, which nanofibre or microfibre is pulled to a rotary set of n electrodes by means of electrostatic field.
• individual electrodes are arranged at regular spacing to each other and at the same distance from the set of electrodes rotation axis and parallel with it. This set of electrodes rotates and thereby the nanofibre or microfibre is wound on it.
• the invention also refers to an apparatus for production of the two-dimensional or three-dimensional fibrous materials of microfibres or nanofibres.
• This apparatus includes at least one spinning nozzle attached to a first potential and a set of electrodes facing the nozzle arranged at regular spacing to each ' other and attached to a second potential. Further it includes an accumulator for collecting microfibres and nanofibres settled between couples of adjacent electrodes.
• Nano-fibrous or micro-fibrous materials with highly fine structure find numerous applications in many fields of advanced medicine, but also of microelectronics, optics and power engineering. Huge surface formed in relatively very small volume is one of the basic advantages of these materials, and inter-fibre spaces (pores) of these materials have very small size. Material with fine internal nano-structure or micro- structure assumes quite new properties that can be considerably different from properties of a volume sample of the same material. Additionally it is possible to control these unique properties and adapt them to requirements of particular application by a controlled production. Future applications count on a use of such materials in various fields of advanced medicine, because such material provides cells in living tissue with very favourable and natural conditions for their growth, motion and reproduction. Unfortunately the usability of such material is considerably limited just because of its internal chaotic structure. Applications of tissue
• Nanofibres or microfibres are deposited directly onto the cylinder surface or are formed in a gap between two rotary rods that are positioned on one rotation axis, see US20070269481. Surface of such collector is one of the electrodes and thus it must be made of a conductive material.
• the fibrous layer is deposited onto the collector and for its subsequent use it must be transferred usually onto quite different underlayment or into another container, etc. And so manually one by one cut out stripes of fibrous material are assembled in thicker 3D structures in examples of embodiments disclosed in patent application US20080208358A1.
• Such a layer is highly fine and a manipulation with the nano-fibrous or micro-fibrous material is complicated, because an irreversible damage of the layer arises very easily already when being taken off from the collector used. Any manipulation with material of a larger area is almost impossible especially with bio. polymeric fibres with very low mechanical resistance.
• Patent application WO20061368 ⁇ 7 ⁇ 1 describes a use of a rotating collector with electrodes longitudinally arranged around an axis of rotation. Geometric dimensions of the collector are not mentioned. Authors give no method for taking off fibres from the collector carefully. No collecting mechanism for fibres deposited onto the rotating collector is solved. The described method does not solve all phases of the production process or more precisely the process is terminated by the fibres deposition.
• This set of electrodes rotates and thereby the nanofibre or microfibre is wound on it.
• the electrostatic field is disconnected and rotation of the electrode set is stopped, and a layer of microfibres or nanofibres formed in the field between two adjacent electrodes is removed.
• the rotary set of electrodes turns through an angle of 360/n and the layer of microfibres or nanofibres formed between, t o adjacent electrodes in the field adjacent to the field, from which a layer was removed in previous step, is removed. This step is repeated n-times till layers of microfibres or nanofibres from all the fields between adjacent electrodes are removed.
• an accumulator turns around slightly to reach a direction of microfibres or nanofibres in the removed layer that is different from the direction of microfibres pr ⁇ nanofibres of the preceding layer.
• an apparatus for production of two-dimensional or three-dimensional fibrous materials of microfibres or nanofibres comprising at least one spinning nozzle connected to a first potential and a set of n electrodes facing the spinning nozzle that are arranged at regular spacing and connected to a second potential, and also an accumulator for collecting microfibres or nanofibres settled between two adjacent electrodes.
• the set of the : electrodes is pivoted in this apparatus and individual electrodes of the set of the electrodes are arranged at regular spacing to each other and at the same distance from the set of electrodes rotation axis and parallel with it.
• the apparatus further comprises the accumulator, which is arranged, in relation to the electrodes, movably in direction of longitudinal axes of the electrodes, for collecting microfibres or nanofibres settled between two adjacent electrodes.
• this accumulator is arranged, in relation to the electrodes, movably in direction perpendicular to the longitudinal axes of the electrodes for it being brought into engagement to collect rhicrbfibres or nanofibres settled between two adjacent electrodes, and being brought but of engagement after finishing the collection of microfibres or nano fibres settled between two adjacent electrodes.
• the accumulator has a shape of parallelogram, the width of which is smaller than a distance between nearest surfaces of a couple of adjacent electrodes to enable its insertion between said adjacent electrodes.
• the accumulator is arranged rbtationally around a line perpendicular to the surface of the collector and passing through' the centre of the collector surface in order that the accumulator may turn around slightly to place a further layer of microfibres or nanofibres settled between two adjacent electrode's with direction of microfibres or nanofibres that is different 1 from the direction of microfibres or nanofibres of the preceding layer. : ⁇ ' ⁇ . ⁇
• the accumulator has a shape of square with its side shorter than a distance between nearest surfaces of a couple bf adjacent electrodes, the accumulator being arranged rotationally around a line perpendicular to the surface of the collector and passing through the centre of the collector surface in order that the accumulator may turn through an angle of 90° to place, a further layer of : microfibres or nanofibres settled between two adjacent electrodes with direction bf microfibres or nanofibres that is perpendicular to the direction of microfibres or nanofibres of the preceding layer.
• the accumulator is made in the form of a dish for depositing the collected layers of nanofibres or microfibres ⁇ the apparatus being further provided with a piston for compression of the fibres into the accumulator and for compaction of individual collected layers of nanofibres or microfibres to mechanically strengthen ordered 3D structure.
• a piston for compression of the fibres into the accumulator and for compaction of individual collected layers of nanofibres or microfibres to mechanically strengthen ordered 3D structure.
• the accumulator is arranged rotationally around a line perpendicular to the surface of the collector and passing through the centre of the collector surface in order that the accumulator may turn around slightly to place a further layer of microfibres or nanofibres settled between two adjacent electrodes with direction of microfibres or nanofibres that is different from the direction of microfibres or nanofibres of the. preceding layer.
• FIG. 1 is a flow chart of particular phases of the production process as suggested in solution according to the present invention.
• Fig. 2 is a flow chart of particular phases of the production process as suggested in solution according to the present invention.
• FIG. 6 represents an exemplary embodiment of an apparatus for the production of fibrous materials with anisotropic properties.
• Side sectional elevation of longitudinal electrodes of a rotating collector with accumulator is on Fig. 3, and further exemplary embodiment is on Fig. 4a.
• Fig. 4b shows a cross section of four and five longitudinal electrodes of a rotating collector, whereas principal of parallel ordered fibres formation is depicted.
• principal of the production of perpendicular fibres in two steps with exemplary use of four and five longitudinal electrodes of the rotating collector is shown, on Figs. 5a and 5b.
• Photos of parallel and perpendicular ordered fibres from an electron microscope are on Figs. 6 and 7.
• a movable accumulator 7 is a suitable dish that enables easy further treatment of the fibrous material (e.g. in production of composite materials).
• the subject matter of the invention is a comprehensive production process of new materials that is divided into particular process phases, the exemplary sequence of which is shown on Fig. 1.
• a spinning mixture is prepared in the first step.
• the solution or. melt 1 is measured out into a spinning nozzle 3, after which a high electric voltage is connected, which gives rise to a fibre 5 with a diameter ranged from microfibres to nanofibres.
• the fibre 5 moves in the electrostatic field in the direction to a collector 9.
• Fibres 5 are deposited onto the rotating collector 9 in one preferred direction. After a layer 8 of fibres 5 was created on the collector, the deposited fibres 5 are collected and layers 8 of. these fibres 5 are in turn superimposed, while the degree of their order is maintained.
• the fibre layers 8 are compressed, through which a finished product that can be enfolded in a wrapping material, or a semi product intended for further processing such as an application of suitable medium so that the resulted product may be a composite material and gain required properties, comes into existence. It is possible to enfold the finished product in the wrapping material with the shape of a tray that makes manipulation easier and is also suitable for subsequent treatments of fibre layers 8 such as embedding the layer 8 of fibres 5 with another medium in order to get a composite material, and thus a final product comes into existence. Removing and transfer of the product is a final phase.
• phase phases are implemented automatically in a deposition chamber without any intervention of an operator and without being affected by external environment, which makes it possible to ensure the process sterility and a high quality of final products.
• the production process phases are represented in the flow chart on Fig. 1 , where repeated process phases are also indicated. The process is repeated from the beginning unless a sufficient layer 8 of fibres 5 is collected by the accumulator 7 at the moment of solution 1 reserve exhaustion in phases "Fibres deposition" or "Superimposing”.
• FIG. 2 An exemplary embodiment of an apparatus for production of two-dimensional or three-dimensional fibrous materials composed of nanofibres or microfibres, hereinafter referred to as fibres .5., is on Fig. 2.
• This apparatus comprises a jet emitter 2 filled with solution 1 of polymer and equipped with spinning nozzle 3.
• the spinning nozzle 3 is connected to a first potential, i.e. to one of poles of a source 4 of DC electric voltage.
• the second pole of the, source 4 of DC electric voltage is connected to the collector 9 facing the spinning nozzle 3,
• the collector 9 is composed of electrodes 6 that are arranged longitudinally at regular spacing to each other and at the same distance from the collector 9 rotation axis x.
• the accumulator 7 is arranged movably, in relation to the electrodes : 6, in direction parallel; with the rotation axis x of the collector 9 so that the accumulator 7 may collect layers 8 of fibres 5 settled between two adjacent electrodes 6.
• Fig. 3 schematically depicts a side view of an accumulating mechanism with the planar accumulator 7. Fibres 5 are deposited by electrostatic spinning onto the electrodes 6 of the collector 9. Afterwards the fibres 5 are deposited onto a surface of the accumulator 7 while their order is maintained.
• the accumulator 7 is planar. It is inclined in relation to the rods of the electrodes 6 of the collector 9 at an angle or , and moves in translator/ movement in the direction that forms an angle ⁇ with the axis x of the collector.
• Fig. 4a schematically depicts a cross-section of the collector 9 with four electrodes 6 and the accumulator 7. Fibres 5 are deposited by electrostatic spinning on the conductive rods of the electrodes 6 of the collector 9.
• the fibres 5 are deposited on a surface of the accumulator 7 while their order is maintained.
• the collector 9 is equipped with four electrodes 6.
• the squared accumulator 7 removed a layer 8 of fibres 5 from the field between two upper electrodes.
• the collector 9 is turned through an angle of 90° and the accumulator 7 removes another layer 8 of fibres 5 with the same orientation. .
• Fig. 4b schematically depicts a cross-section of the; collector 9 with five electrodes 6 and the accumulator 7.
• Fibres 5 are deposited by electrostatic spinning onto the conductive rods of the electrodes 6 of the collector 9. Afterwards the fibres 5 are deposited on a surface of the accumulator 7 while their order is maintained.
• the collector 9 is equipped here with five electrodes 6.
• the squared accumulator 7 removed a layer 8 of fibres 5 from the field between the two upper electrodes.
• the subsequent phase is depicted, where the. collector 9 is turned through an angle of 360/5, i.e. 72° and the accumulator 7 removes another layer 8 of fibres 5 with the same orientation. There are two layers 8 of fibres 5 with the same orientation on the accumulator 7.
• Fig. 5a schematically depicts a cross-section of the collector 9 with four electrodes 6 and the accumulator 7. Fibres 5 are deposited by electrostatic spinning on the conductive rods of the electrodes 6 of the collector 9. Afterwards the fibres 5 are deposited on the surface of the accumulator 7, while their order is maintained.
• the collector 9 is equipped with four electrodes 6.
• the squared accumulator 7 removed a layer 8 of fibres 5 from the field between the two upper electrodes.
• the subsequent phase is depicted, where both the collector 9 and the accumulator 7 are turned through an angle of 90° and the accumulator 7 removed another layer 8 of fibres 5.
• the orientation of fibres 5 of the first layer 8 is perpendicular to the orientation of fibres 5 of the second layer 8.
• Fig. 5b schematically depicts a cross-section of the collector 9 with five electrodes 6 and the accumulator 7.
• Fibres 5 are deposited by electrostatic spinning onto the conductive rods of the electrodes 6 of the collector 9. Afterwards the fibres 5 are deposited on the surface of the accumulator 7, while their order is maintained.
• the collector 9 is equipped here with five electrodes 6.
• the squared accumulator 7 removed a layer 8 of fibres ⁇ from the field between the two upper electrodes.
• the subsequent phase is depicted, where the collector 9 is turned through an angle of 360/5, i.e. 72°, and the accumulator 7 is turned through an angle of 90° and removes another layer 8 of fibres 5.
• the orientation of fibres 5;of the first layer 8 is perpendicular to the orientation of fibres 5 of the second layer 8.
• Fig. 6 is a photo from an electron microscope at magnification 5000-times, where several layers 8 of fibres 5 superimposed with the same orientation are depicted.
• Fig. 7 is a photo from an electron microscope at magnification 1000-times, where several layers 8 of fibres 5: are depicted, whereas layers 8 were superimposed in such a way that the orientation of fibres 5 of one layer 8 is perpendicular to the orientation of fibres 5 of the previous layer 8.
• a prepared spinning mixture is dosed into the jet emitter 2. Afterwards a high electric voltage is connected and it causes that the solution or melt begins tq escape out of the spinning nozzle 3 creating fibre 5 with diameter ranging from microfibres to nanofib res. This fibre 5 moves in the
• the fibres 5 are deposited onto the rotating collector 9 in one preferred direction. After the layer 8 of the fibres 5 was formed on the collector 9, high electric voltage is disconnected and the fibre 5 quits escaping out of the spinning nozzle 3. Thereafter the accumulator 7 collects the settled fibres 5, and the layers 8 of these fibres 5 are step by step superimposed, while their degree of order is maintained. According to requirements on the resulted material, the layers 8 of the fibres 5 are superimposed so that the fibres 5 orientation may be the same in all layers, or it is possible to turn the orientation of the fibres 5 in each subsequent layer 8 through an angle, usually through 90°.
• fibres 5 deposited onto the surface of the accumulator 7 have a higher degree of order than fibres 5 settled onto a surface of a rotating cylinder because further straightening of them in one direction occurs just by a movement of the accumulator 7.
• degree of order of the internal fibrous material structure is higher than that of the material that was formed on the surface of the rotating cylinder. .
• Another advantage of this embodiment when compared with stationary segmented collector with planar electrodes, is multiple lengths of ordered nanofibres, which enables to produce materials of larger area or volume with very well ordered internal structure.
• revs of the collector 9 first of all electrostatic forces, which act transversely between particular electrodes 6 of the collector 9, contribute to the fibre 5 orientation.
• mechanical forces which capture flying fibre 5 and attract it to the- electrodes 6 of the collector 9 namely in one direction, i.e. perpendicular, to the electrodes 6, join the electrostatic forces contributing to ordered depositing of the fibres 5 onto the collector 9.
• Yet another advantage is the possibility of implementation of all the production cycle phases in a single closed apparatus, namely in a deposition chamber, where an automatic production without an operator intervention and without being influenced by external environment is ensured, which enables to ensure the process sterility and a high quality of resulting products.
• the rotating collector 9 with the set 11 of the electrodes 6 connected to the second potential comprises at least three longitudinal electrodes 6, generally N electrodes 6, and the accumulator 7 that moves successively always between two adjacent electrodes 6 in such a way, that the accumulator 7 movement direction is determined by combining a movement in direction of the common axis x of rotation of the electrodes 6 of the collector 9, and a movement in direction that forms with the axis x a specified angle ⁇ .
• the accumulator degree of incline is defined by an angle a.
• an angle y is defined, which specifies an angular displacement of the accumulator and the collector ⁇ to each other.
• the rotating collector 9 with electrodes 6 connected to the second potential includes at least three longitudinal electrodes 6, generally N electrodes 6, and the accumulator 7 that moves
• Yet another exemplary embodiment of the apparatus comprises the rotating collector 9 with four longitudinal electrodes 6, and the accumulator 7, which moves in a direction perpendicular to said electrodes 6 axes for enabling of an insertion of inclinable plates of the accumulator 7 between said neighbouring electrodes 6 and their release and in the lengthwise direction along the electrodes 6.
• the accumulator 7 is provided with four said inclinable plates capturing on their surfaces fibres 5 settled between two closest adjacent electrodes 6.
• the collector 9 is comprised of more than three conductive electrodes 6 that are arranged at regular spacing to each other and at the sameidistance from a common rotation axis x.
• accumulator 7 has a shape of a disc and is provided with appropriate notches that enable sliding the accumulator onto the longitudinal electrodes 6 so that its movement along the rotation axis x and in the vicinity of these electrodes 6 may be enabled.
• fibres 5, which were deposited in an orderly manner between adjacent electrodes 6, are placed spontaneously directly onto a surface of the accumulator 7, where stripes of new material are formed, which stripes are composed of uniaxial ordered fibres 5 with high degree of orientation.
• Another advantageous embodiment comprises the cylindrical collector 9 composed of at least two longitudinal electrodes 6, generally of total number of N, where N is a natural number, parallelly arranged electrodes, the distance of which ranges from 0.1 mm to ( d/N) mm, where d is double distance of the electrodes 6 from the common rotation axis x.
• very thin conductive wires are used as the electrodes 6, in the second limit case the electrodes 6 form an integral conductive surface of the cylinder.
• first limit case fibres 5 are captured onto the very thin electrodes 6 and resulting material is composed of very well ordered fibres 5 only, the fibres having their diameter ranging from microfibres to nanofibres.
• the second limit case fibres 5 are wiped off in the same way as above mentioned, whereas during the fibres 5 depositing a yarn or a filament is formed that is composed of multiple fibres 5 with a total length of tr.d.
• the accumulator 7 has a shape of a dish for accumulating the collected layers 8 of fibres 5.
• the fibres 5 are compressed into the accumulating dish by means of a simple piston motion.
• Individual layers 8 are compacted in the dish and that way the ordered 3D structure is also mechanically strengthened.
• the dish serves for further treatment of the product, e.g. by imbedding fibres 5 with another solution, generally with another medium, a composite material of required properties is produced.
• Example 1 Fibrous layer composed of parallel fibres.
• Fibres of 16% aqueous solution 1 of polyvinyl alcohol (PVA) were extruded from a jet emitter 2 through a spinning nozzle 3, and deposited onto a segmented collector 9 (Fig. 2).
• the electrodes 6 of the collector 9 were distant 2 cm vertically from the spinning nozzle 3.
• the collector 9 was provided with four longitudinal electrodes 6 in the shape of thin wires of a circular cross-section with a diameter of 0.8 mm.
• the electrodes 6 distances were 25 mm to each other.
• the collector 9 was set spinning at 2000 revs per minute, which corresponds to the collector linear surface speed of 3.7 meter per minute.
• Another source 4 of high voltage was connected between the spinning nozzle 3 and the collector 9 and its output was set to 28 kV. Electrostatic forces gave rise to a formation of a fibre 5 with a diameter ranging from micfofibres to nanofibres,. which fibre was in turn deposited between the electrodes 6 in the form of a layer 8 of the ordered fibres 5. After 30 seconds the fibre 5 depositing was interrupted and the rotating collector was stopped or a power supply of the collector 9 motor and the high voltage source 4 were switched off. Afterwards the layer 8 of the fibres 5 was wiped off by a slow motion v(t) of the accumulator 7 along the electrodes 6 of the collector 9, whereas the
• Example 2 Material with regular 3D structure composed of fibres
• Fibres 5 of a diameter ranging from microfibres to nanofibres were deposited onto the rotating collector 9 with four longitudinal electrodes in the same way as
• accumulator 7 was in motion along the conductive rodlike electrodes 6 of the collector 9 so that the first layer of the fibres 5 was formed on a surface of the accumulator 7. Afterwards the whole collector 9 turned through an angle of 90° and simultaneously also the squared accumulator 7 sized 25x25 mm turned through an angle of 90°. The accumulator 7 was set in motion along the conductive rodlike electrodes 6 of the collector 9, during which time the second layer of fibres 5 was being deposited. The fibres 5 in the second layer 8 were deposited perpendicularly to the fibres 5 of the first or the preceding layer 8. This process was repeated four times until all the fibres 5 were wiped off the collector 9. Thereafter the collector 9 was set spinning and the spinning process was started. The sample produced by this process has a regular 3D structure of an area of (25x25) mm 2 . An example of such material surface is shown in Fig. 7, which is a photo from electron microscope at
• the present invention can be used for production of materials that are areal (2D) or voluminous (3D) from the macroscopic point of view, and which are composed of nanofibres or microfibres, whereas the internal fibrous structure of these materials is regular, ordered in one direction or in more directions.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

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• 2011
  • 2011-06-27 CZ CZ20110376A patent/CZ2011376A3/cs not_active IP Right Cessation
• 2012
  • 2012-06-22 CN CN201280031598.XA patent/CN103687984A/zh active Pending
  • 2012-06-22 JP JP2014517445A patent/JP2014523492A/ja not_active Withdrawn
  • 2012-06-22 EP EP12743876.0A patent/EP2723925B1/en not_active Not-in-force
  • 2012-06-22 RU RU2014102114/12A patent/RU2014102114A/ru not_active Application Discontinuation
  • 2012-06-22 WO PCT/CZ2012/000055 patent/WO2013000442A1/en active Application Filing
  • 2012-06-22 KR KR1020147002173A patent/KR20140045515A/ko not_active Application Discontinuation
  • 2012-06-22 BR BR112013032549A patent/BR112013032549A2/pt not_active IP Right Cessation
  • 2012-06-22 US US14/128,653 patent/US20140284827A1/en not_active Abandoned
  • 2012-06-22 CA CA2838281A patent/CA2838281A1/en not_active Abandoned

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