1. An electrospun fiber producing apparatus comprising an electrospinning device coupled with scotch yoke mechanism, said apparatus comprises: - a spinneret (1), - a slider (7), - a spinneret mount head (12) connecting the spinneret with the slider, - a metal collector (4), - a crank disc (6), - a slider support holder (8) to hold the slider in position, - a motor (13) to rotate the crank disc (6), - a supply pipe (2) connected to a reservoir of polymer solution through an infusion pump, - a power source to create electric field between the spinneret (1) and the metal collector (4), wherein said apparatus is configured such that horizontal to-and- fro movement of the spinneret (1) can be controlled to produce electrospun fiber mat of desired and uniform thickness over a pre-determined area on the metal collector (4).

2. The apparatus as claimed in claim 1, wherein said spinneret (1) comprises : - a needle holder (1a) - a metallic blunt edge needle (1b) having single orifice at the tip of the needle (1c), wherein said metallic blunt edge needle is connected to the front end of the needle holder, and back end of the needle holder connected with a supply pipe (2).

3. The apparatus as claimed in claim 1, wherein said slider comprises : - a vertical segment (7a) comprising two parallel rectangular bars separated by a distance, the upper ends of the parallel bars connected by an upper rectangular bar and lower ends of the parallel bars connected by lower rectangular bar, - a horizontal segment (7b) connected to the vertical segment (7a) at one end and to the spinneret (1) at other end through the spinneret mount head (12).

4. The apparatus as claimed in any of the preceding claims, wherein said spinneret mount head (12) comprises : - a bar (12d) of dimension corresponding to a part of the horizontal segment (7b) and placed above the part of horizontal segment (7b), - a needle mount holder groove (12b) on front side of the spinneret mount head (12) formed by equal and corresponding grooves on the bar (12b) and the corresponding part of the horizontal segment(7b), such that the needle holder (1b) can fit inside the needle mount holder groove (12b), - a hole (12c) for the supply pipe (2) at the back side of the spinneret mount head (12), formed by equal and corresponding grooves on the bar and the corresponding horizontal segment, the hole (12c) being of diameter slightly greater than the diameter of the supply pipe (2), - screws (12a) to place the needle holder (1a) tight inside the groove (12b), the bar (12d) and the corresponding part of the horizontal segment (7b) being of dimension corresponding to the needle holder (1b) such that the needle holder (1b) can fit inside the needle mount holder groove (12b), wherein the spinneret mount head (12) allows the horizontal to-and-fro movement of the spinneret corresponding to the horizontal movement of the horizontal segment (7b) of the slider.

5. The apparatus as claimed in any of the preceding claims, wherein said crank disc (6) has pinholes (11, 11a, 11b, …, 11n) located at variable positions, wherein a pin (10) is mounted in the pin hole (11, 11a, 11b, …, 11n) of desired position and pinhead is coupled with the vertical segment (7a) of the slider (7), such that circular movement of the crank disc (6) causes vertical movement of the vertical segment (7a) of the slider (7) corresponding to the circular movement of the crank disc (6), eventually leading to corresponding to-and-fro horizontal movement of the horizontal segment (7b) of the slider (7).

6. The apparatus as claimed in any of the preceding claims, wherein magnitude of the horizontal movement of the horizontal segment (7b) is controlled by the position of the pin (10) on the pin hole of the crank disc (6), leading to corresponding control in magnitude of the horizontal to-and-fro movement of the spinneret (1), thereby depositing the fiber mat over the pre-determined area on the metal collector (4).

7. The apparatus as claimed in claim 6, wherein the closer is the position of the pin (10) to the center of the vertical segment (7a), the smaller is the magnitude of horizontal to-and-fro movement of the spinneret.

8. The apparatus as claimed in any of the preceding claims, wherein said pre-determined area (4) on the metal collector (5) is determined by the magnitude of the horizontal to-and-fro movement of the spinneret.

9. The apparatus as claimed in claim 3, wherein the distance between two parallel rectangular bars of the vertical segment is greater than the diameter of the pin (10).

10. The apparatus as claimed in claim 3, wherein horizontal segment (7b) of the slider (7) is kept in position by a slide support holder (8).

11. The apparatus as claimed in claim 1, wherein the apparatus is placed on a platform (9), the metallic collector is placed on a support stand (15), electric motor (13) is placed on a support stand (14).

12. A method to operate apparatus as claimed in any of the preceding claims, said method comprises the steps of: - feeding of a polymer solution to the spinneret (1) through the supply pipe (2), - rotating circular crank disc (6) by the electric motor (13) at desired frequency (rpm), causing controlled vertical movement of vertical segment and corresponding horizontal to-and-fro movement of horizontal segment, leading to controlled horizontal to-and-fro movement of the spinneret, - creating specific high electric field between spinneret and metallic collector, causing repulsive force among the particles of polymer solution at the spinneret tip (1c), - extrusion of polymer solution of charged particles from orifice at the tip of the spinneret (1) creating a cone shaped electrospinning region (3), - deposition of the fiber mat (5) over a pre-determined area on the metallic collector (4) wherein magnitude of the to-and-fro movement of the horizontal segment (7b) can be controlled by selecting the different position of the pin (10) on the disc as shown pin holes (11) on the disc, leading to controlling corresponding to-and-fro movement of the spinneret (1), thereby enabling deposition of the fiber mat (5) of desired and uniform thickness on the pre-determined area of the collector (4).

13. The method as claimed in claim 12, wherein said method enables deposition of fiber mat (5) of desired and uniform thickness over the pre-determined area on the metal collector (4).

14. An electrospun fiber producing apparatus comprising an electrospinning device coupled with scotch yoke mechanism and a method to operate thereof, substantially as hereinbefore described with reference to the accompanying specification, drawings and any of the preceding claims.

FIELD OF INVENTION:

The present invention relates to an electro spun fiber producing apparatus. The apparatus comprises an electrospinning device coupled with scotch yoke mechanism enabling controlled horizontal movement of a spinneret of the electrospinning device to obtain fiber mat of desired and uniform thickness over a pre-determined area on a collector. The present invention also provides a method to operate the electrospun fiber producing apparatus of the present invention.

BACKGROUND OF THE INVENTION:
Electrospinning is a fiber deposition technique involving electrostatic driven process used to produce electrospun fibers from a polymer solution. The diameter of these fibers typically ranges between tens of nanometers to a few micrometers. Electrospinning is a potential approach for producing nanofibers due to its versatility of processing to create fibers with multiple arrangements and morphological structures for use in technical applications such as energy conversion, energy storage, medical and healthcare, biotechnology, environmental engineering, pharmaceutical manufacturing, tissue engineering, regenerative medicine, defence and security.

A typical electrospinning device consists of a reservoir to contain polymer solution, a stationary spinneret through which the jet of polymer solution is extruded, an infusion pump connecting the reservoir to the spinneret through a pipe, a high voltage power source and a collector. A specific voltage is applied between the spinneret and the metal collector to create very high electric field between the tip of the spinneret and the collector. This high electric field causes particles within the solution inside the spinneret tip get charged, and thereby creating a repulsive force. When this repulsive force exceeds the surface tension of the polymer solution, a Taylor cone is formed at the tip of the spinneret and finally a jet of polymer solution is drawn. Initially the jet is in a single rectilinear form, which later forms a cone shaped electrospinning region due to bending instability and electrically driven axisymmetric instabilities, looping, spiral trajectories as well as branching of the jet. The diameter of the jet reduces due to solvent evaporation, but entanglements of the polymer chain prevent breaking up. This results in the formation of fibers of nano to submicron size diameter being deposited on the collector. The fibers deposited on the stationary collector form a non-woven fiber-web or fiber mat. This non-woven fiber mat is desired to have large area and uniform thickness with a process for high throughput.

Apparatus for electrospinning from a single orifice and process for producing a single jet are disclosed in US Pat. No. 8,178,030B2, and US Pub. Nos. 2003/0215624A1, 2009/0032475A1, 2010/0233812A1, and 2011/0082565A1. However, the apparatus of electrospinning consists of stationary spinneret, thereby forming a non-uniform fiber-mat. The fiber gets deposited more at the center, causing gradual decrease in thickness towards the edges.

Further, US Pub. No. 2002/0122840A1 and 2002/0175449A1 describe electrospinning of polymer solutions through one or more charged conducting nozzles arranged on at least one conducting plate.

EP2907902B1 discloses an electrospinning device comprising an electrode having a concave curved surface and a needle-shaped spinning nozzle surrounded by the concave curved surface of the electrode and being configured to jet a spinning solution from a tip of the nozzle with an electric field applied between the electrode and the nozzle to form a nanofiber from the jetted spinning solution, the concave curved surface of the electrode having an open end defining a circle, the nozzle being located in such a manner that a direction in which the nozzle extends passes through or near the center of the circle defined by the open end of the concave curved surface of the electrode, and that the tip of the nozzle is positioned in or near a plane including the circle defined by the open end of the concave curved surface of the electrode. The nozzle is divided into a plurality of sections in its transverse cross-section, and the spinning solution is to flow through each of the plurality of sections.
US Pub. No. 2007/022563A1, 2008/0241297A1, 2008/0277836A1, and European Patents EP 1967617A1, 1975284A2 and 1992721 disclose additional orifices and banks of orifices in two-dimensional blocks or single lines. However, one issue of the multiple orifices producing multiple jets is the repulsion between the multiple jets due to the jets having the same or similar electric charge. The repulsion between the jets can cause bending, as well as possible suppression of the jets; thus, jet stability suffers, resulting in one or more of erratic spinning, less uniform deposition of fibers, a wider range of fiber diameters, and fiber breakage.

US Pub. No. 2003/016294 A1 discloses a rotating disc spray head consisting of multiple spinnerets. However due to rotation of the disc, it gets twisted. Also, it becomes difficult in design when a high field is applied between rotating spinneret and collector.

Therefore, there is a need to develop a cost effective and user friendly electrospun fiber producing apparatus that provides fiber-mat deposition in uniform thickness over a large area. It is also desired that the components of the apparatus are non-metallic to avoid any high electric field interferences.

OBJECT OF THE INVENTION:
In order to obviate the drawbacks in the existing state of the art, the main object of the present invention is to provide an electrospun fiber producing apparatus to deposit electrospun fibers of uniform thickness over a large area.

Another object of the present invention is to provide a nanofiber producing apparatus comprising an electrospinning device coupled with scotch yoke mechanism enabling horizontal movement of a spinneret of the electrospinning device to deposit fiber of uniform thickness over a large area.

Yet another object of the invention is to provide a method to operate an electrospun fiber deposit apparatus of the present invention comprising an electrospinning device coupled with scotch yoke mechanism enabling horizontal movement of a spinneret of the electrospinning device to deposit fiber of uniform thickness over a large area.

SUMMARY OF INVENTION:
Accordingly, the present invention provides an electrospun fiber producing apparatus to deposit electrospun fibers of uniform thickness over a large area. The apparatus comprises an electrospinning device coupled with scotch yoke mechanism. The apparatus enables horizontal movement of a spinneret of the electrospinning device to deposit electrospun fiber of desired and uniform thickness over a pre-determined area.

The spinneret of the device is fixed at the end of a horizontally movable horizontal segment of a slider of the scotch yoke mechanism, causing to-and-fro horizontal movement of the spinneret at a pre-determined magnitude. The controlled periodic movement of the spinneret leads to deposit of fibers over a pre-determined area.

The magnitude of the horizontal movement of the spinneret is controlled by a cylindrical knub position along the diameter of a circulating disc of the scotch yoke mechanism and also depends on diameter of the circulating disc. Frequency of the movement is controlled by the revolution per minute (rpm) of electric motor used to rotate the circular disc.

As the fibers are continuously extruded from tip of the spinneret and simultaneously making a to-and-fro horizontal movement, the fibers of uniform thickness keep depositing on a collector on a pre-determined area. The collector can be a static plate or a moving drum collector.

These and other aspects of the embodiments herein will be better appreciated and understood from the following detailed descriptions, drawing, and claims. Moreover, it should be understood that both the foregoing summary and detailed description of the present disclosure are exemplary and intended to provide further illustration, and not of limitations.

BRIEF DESCRIPTION OF THE DRAWINGS:
Fig. 1 depicts a typical electrospinning mechanism.
Fig. 2 depicts schematic representation of an electrospinning apparatus as viewed from front in accordance with the present disclosure.
Fig. 3 depicts schematic representation of an electrospinning apparatus as viewed from side in accordance with the present disclosure.
Fig. 4 depicts schematic representation of enlarged view of the spinneret arrangement attached to supply pipe.
Fig. 5a, 5b and 5c depicts representative expanded view of the embodiments of spinneret mount head from front, back and side view, respectively, in accordance with the present disclosure.
Fig. 6 depicts comparison of fiber mat deposition between a typical electrospinning device of single spinneret with single orifice and the apparatus in accordance with the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION WITH NON-LIMITING EMBODIMENTS, EXAMPLES AND ACCOMPANYING DRAWINGS
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein would be contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art. The embodiments and examples provided herein are illustrative only and are not intended to be limiting.

The terminology and structure employed herein is for describing, teaching, and illuminating some embodiments and their specific features. It does not in any way limit, restrict or reduce the spirit and scope of the claims or their equivalents. Any particular and all details set forth herein are used in the context of some embodiments and therefore should not be necessarily taken as limiting factors to the attached claims. The attached claims and their legal equivalents can be realized in the context of embodiments other than the ones used as illustrative examples in the description below.

More specifically, any terms used herein such as but not limited to “includes,” “comprises,” “has,” “consists,” and grammatical variants thereof do not specify an exact limitation or restriction and certainly do not exclude the possible addition of one or more features or elements, unless otherwise stated, and furthermore must not be taken to exclude the possible removal of one or more of the listed features and elements, unless otherwise stated with the limiting language “must comprise” or “needs to include.”

The figures and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. The scope of the embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible.

In view of the foregoing description, numerous changes and variants of the present invention are possible. As a result, it should be understood that, within the scope of the appended claims, the invention may be used in ways other than those disclosed herein. In addition, unless there is a specific statement in the specification to the contrary, the numerical values mentioned for the various physical parameters, dimensions, or quantities are only approximations, and it is assumed that values higher/lower than the numerical values assigned to the parameters, dimensions, or quantities fall within the scope of the disclosure.

Fig. 1 shows an exemplary typical electrospinning device consisting of a stationary spinneret (I), a pipe (II) connecting the infusion pump to the spinneret, a metal collector (IV). The jet of polymer drawn from tip of the spinneret forms a cone shape electrospinning region (III). The fibers deposit on the stationary collector (IV) forming a non-woven fiber-web or fiber mat (V).

The electrospun fiber producing apparatus of the present invention comprises an electrospinning device coupled with scotch yoke mechanism. The apparatus of the present invention comprises a spinneret (1), a metal collector (4), a circulating crank disc (6), a slider (7), a slider support holder (8), a spinneret mount head (12), a power source (not shown), an electric motor (13), support stand for static collector (15) and a platform (9). The entire assembly of components of the apparatus is placed on the platform (9).

As shown in Fig 2 and 3, the spinneret (1) is fixed on a spinneret mount head (12) attached to one end of the slider (7). The circular crank disc (6) is rotated by the electric motor (13) at desired frequency (rpm). The motor (13) is placed on a support stand (14). The slider (7) comprises a vertical segment (7a) and a horizontal segment (7b). The vertical segment (7a), also termed as sliding yoke, comprises two parallel rectangular bars separated by a distance greater than the diameter of a pin (10). There are pinholes (11, 11a, 11b, …, 11n) located at variable positions on the crank disc (6). One end of the pin (10) is mounted on least one pin hole (11, 11a, 11b, …, 11n)) on the crank disc (6) at desired location. Other end of the pin (10) is coupled with slider (7) so as to enable vertical movement of the vertical segment (7a) of the slider (7) corresponding to the circular movement of the crank disc (6). The vertical movement of the vertical segment (7a) eventually leads to corresponding to-and-fro horizontal movement of the horizontal segment (7b) of the slider (7). The position of pin (10) on the crank disc (6) thereby controls the magnitude of the horizontal movement of the horizontal segment (7b). The upper ends of the parallel bars of the vertical segment (7a) of the slider (7) are connected by upper rectangular bar and lower ends of the parallel bars are connected by lower rectangular bar.

The magnitude of the to-and-fro movement of the horizontal bar (7b) can be controlled by selecting the different positions of the pin (10) on the pinhole (11). If the pin (10) is mounted on the pin hole (11) of the disc (6) keeping the other end of the pin (10) close to the center of the vertical segment (7a), the magnitude of to-and-fro motion will be small. Thus, the distance of the pin (10) from the center of the vertical segment (7a) determines the magnitude of the horizontal movement of the horizontal segment (7b), thereby allowing the deposition of the polymer fiber mat over a pre-determined area on the metal collector (4). The metallic collector is placed on a support stand (15).

One end of the horizontal segment (7b) is connected to the vertical segment (7a) and other end is connected to the spinneret (1) through front end of the spinneret mount head (12), passing through a slide support holder (8). When the disc (6) makes a circular movement, the vertical segment (7a) slides over the pin (10), causing to-and-fro movement of the horizontal segment (7b). The width of the slider support holder (8) is determined such that it smoothly balances the to-and-fro movement of the slider (7) as the slider (7) is not symmetric about vertical axis. The back end of the spinneret mount head (12) is connected to the supply pipe (2).

As shown in Fig. 4, the spinneret comprises a needle holder (1a) and a standard metallic blunt edge needle (1b) having single orifice at the tip of the needle (1c). The back end of the needle holder (1a) is connected with the front end of a supply pipe (2). The front end of the needle holder (1a) is connected with the metallic blunt edge needle (1b). The back end of the supply pipe (2) is connected to the front end of an infusion pump (not shown). The back end of the infusion pump is connected to a reservoir containing polymer solution (not shown).

Fig. 5a, 5b and 5c are the expanded view of the spinneret mount head (12) from front, back and side, respectively. The spinneret mount head (12) comprises a needle mount holder groove (12b) of dimension corresponding to the needle holder (1b), so that the needle holder (1b) can fit inside the needle mount holder groove (12b). Screws (12a) are provided to place the needle holder (1a) tight inside the groove (12b). The spinneret mount head (12) comprises a bar (12d) of specific length on the horizontal segment (7b). The dimension of the bar is such that it corresponds to the dimension of the horizontal segment (7b). The bar (12d) and the horizontal segment (7b) are placed parallel, bar (12d) being placed above the corresponding part of the horizontal segment (7b). Both the bar (12d) and the horizontal segment (7b) have grooves of equal sizes, together forming a needle mount holder groove (12b). A hole (12c) for the supply pipe (2) is also provided at the back side of the spinneret mount head (12). The hole (12c) is of diameter slightly greater than the diameter of the supply pipe (2) and also made up by the corresponding grooves in the bar (12d) and the horizontal segment (7b).

A suitable electric field of few tens of kV can be applied through a DC power source (not shown) between the conductive spinneret needle (1b) and the metallic collector (4). The polymer solution at the tip of the spinneret needle (1b), usually kept at higher positive potential gets charged creating a repulsive force among the solution particles. When the repulsive force surpasses the surface tension of the solution, a jet of polymer solution containing charged particles is extruded from the tip of the spinneret (1c) propelling towards the metallic collector (4) forming an electrospinning zone (3). Due to multiple instabilities such as bending instability, electrically driven axisymmetric instabilities, and looping, the electrospinning zone (3) is stretched out in branches and spiral trajectories, forming a cone shape, before depositing on the collector (4) to form a non-woven fibre mat (5) on the pre-determined area.

The invention also provides a method to operate the apparatus of the present invention. The polymeric solution is fed to the spinneret (1) through the supply pipe (2). The circular crank disc (6) is rotated by the motor (13) at desired revolution per minute (rpm). The motor (13) is directly connected to the disc (6) and the disc is coupled with the slider (7) through the cylindrical smooth pin (10). The vertical segment (7a) of the slider (7) slides over the pin (10) vertically when the disc (6) makes a circular movement. This causes the horizontal to-and-fro movement of the horizontal segment (7b), eventually leading to horizontal to-and-fro movement of the spinneret (1). The magnitude of the to-and-fro movement of the horizontal segment (7b) can be controlled by selecting the different position of the pin (10) on the disc as shown pin holes (11) on the disc. The magnitude of the to-and-fro movement of the horizontal segment (7b) and corresponding to-and-fro movement of the spinneret (1) determines the area of deposition (5) of the fiber mat (5) on the collector (4).

Example 1:
Table 1 shows a non-limiting example of dimension and materials used for the electrospun fiber deposit apparatus of the present invention.
Items Dimension Materials
1 – Spinneret
1a – Needle holder Diameter = 1.08 cm
Depth = 0.75 cm Plastic
1b – Standard metallic blunt needle Standard needle (21, 22, 23, 25 G) Metallic
1c- Tip of the needle - Metallic
2 – Supply pipe Diameter = 0.32 cm Plastic
3–Cone shaped electrospinning fiber region - -
4 – Static metal collector Length x Width = 20 x 20 cm Aluminium
5 - Collected fiber mat - -
6 – Circulating crank disc Diameter = 20 cm Acrylic
7a– Slider yoke Width = 1.1 cm
Breadth = 1.1 cm
Length = 22.0 cm
Gap between vertical bar = 0.95 cm Acrylic
7b- Horizontal connecting bar Width = 1.1 cm
Breadth = 1.1 cm
Length = 30.0 cm Acrylic
8 – Slider support holder Width = 7.0 cm
Breadth = 5.0 cm
Height = 16.0 cm Acrylic
9 – Platform Width = 23.0 cm
Breadth = 10.0 cm Acrylic
10 – Pin Diameter = 0.65 cm
Height = 2.3 cm Acrylic
11 - Pin hole Diameter = 0.65 cm -
12 – Spinneret mount head

Acrylic
12a- Tighting screw Diameter = 0.25 cm
Height = 1.5 cm Acrylic
12b- Needle mount holder groove
Diameter = 1.08 cm
Depth = 0.75 cm -
12c- Hole for supply pipe Diameter = 1.0 cm -
12d- Spinneret mount head upper bar Width = 1.1 cm
Breadth = 1.1 cm
Length = 4.0 cm Acrylic
13 – DC motor (low rpm) - -
14 – DC motor support stand Height = 16 cm Acrylic
15 – Support stand for static metal collector Any insulating materials

The comparative study of fiber deposition in the form of fiber mat (5) on the collector (4) by a stationary spinneret as compared to movable spinneret of the present disclosure is carried out and shown in Fig. 6. In case of stationary spinneret, the deposition is maximum at the center of the fiber mat (5) and gradually decreases outward following a typical Gaussian type distribution. Further, the area of deposition is small and cannot be changed as per the requirement. On the other hand, in case of horizontally movable spinneret of the present invention, the distribution of polymeric jet on the collector (4) is of uniform thickness spread out at the pre-determined area.

Therefore, the apparatus of the present invention provides production of fiber mat of uniform and desired thickness over a desired area. The area of deposition of the fiber mat can be changed as per the requirement. The apparatus of the present invention is scalable for commercial and industrial use.

WE CLAIM:

1. An electrospun fiber producing apparatus comprising an electrospinning device coupled with scotch yoke mechanism, said apparatus comprises:
- a spinneret (1),
- a slider (7),
- a spinneret mount head (12) connecting the spinneret with the slider,
- a metal collector (4),
- a crank disc (6),
- a slider support holder (8) to hold the slider in position,
- a motor (13) to rotate the crank disc (6),
- a supply pipe (2) connected to a reservoir of polymer solution through an infusion pump,
- a power source to create electric field between the spinneret (1) and the metal collector (4),
wherein said apparatus is configured such that horizontal to-and- fro movement of the spinneret (1) can be controlled to produce electrospun fiber mat of desired and uniform thickness over a pre-determined area on the metal collector (4).
2. The apparatus as claimed in claim 1, wherein said spinneret (1) comprises :
- a needle holder (1a)
- a metallic blunt edge needle (1b) having single orifice at the tip of the needle (1c),
wherein said metallic blunt edge needle is connected to the front end of the needle holder, and back end of the needle holder connected with a supply pipe (2).
3. The apparatus as claimed in claim 1, wherein said slider comprises :
- a vertical segment (7a) comprising two parallel rectangular bars separated by a distance, the upper ends of the parallel bars connected by an upper rectangular bar and lower ends of the parallel bars connected by lower rectangular bar,
- a horizontal segment (7b) connected to the vertical segment (7a) at one end and to the spinneret (1) at other end through the spinneret mount head (12).
4. The apparatus as claimed in any of the preceding claims, wherein said spinneret mount head (12) comprises :
- a bar (12d) of dimension corresponding to a part of the horizontal segment (7b) and placed above the part of horizontal segment (7b),
- a needle mount holder groove (12b) on front side of the spinneret mount head (12) formed by equal and corresponding grooves on the bar (12b) and the corresponding part of the horizontal segment(7b), such that the needle holder (1b) can fit inside the needle mount holder groove (12b),
- a hole (12c) for the supply pipe (2) at the back side of the spinneret mount head (12), formed by equal and corresponding grooves on the bar and the corresponding horizontal segment, the hole (12c) being of diameter slightly greater than the diameter of the supply pipe (2),
- screws (12a) to place the needle holder (1a) tight inside the groove (12b),
the bar (12d) and the corresponding part of the horizontal segment (7b) being of dimension corresponding to the needle holder (1b) such that the needle holder (1b) can fit inside the needle mount holder groove (12b),
wherein the spinneret mount head (12) allows the horizontal to-and-fro movement of the spinneret corresponding to the horizontal movement of the horizontal segment (7b) of the slider.
5. The apparatus as claimed in any of the preceding claims, wherein said crank disc (6) has pinholes (11, 11a, 11b, …, 11n) located at variable positions, wherein a pin (10) is mounted in the pin hole (11, 11a, 11b, …, 11n) of desired position and pinhead is coupled with the vertical segment (7a) of the slider (7), such that circular movement of the crank disc (6) causes vertical movement of the vertical segment (7a) of the slider (7) corresponding to the circular movement of the crank disc (6), eventually leading to corresponding to-and-fro horizontal movement of the horizontal segment (7b) of the slider (7).
6. The apparatus as claimed in any of the preceding claims, wherein magnitude of the horizontal movement of the horizontal segment (7b) is controlled by the position of the pin (10) on the pin hole of the crank disc (6), leading to corresponding control in magnitude of the horizontal to-and-fro movement of the spinneret (1), thereby depositing the fiber mat over the pre-determined area on the metal collector (4).
7. The apparatus as claimed in claim 6, wherein the closer is the position of the pin (10) to the center of the vertical segment (7a), the smaller is the magnitude of horizontal to-and-fro movement of the spinneret.
8. The apparatus as claimed in any of the preceding claims, wherein said pre-determined area (4) on the metal collector (5) is determined by the magnitude of the horizontal to-and-fro movement of the spinneret.
9. The apparatus as claimed in claim 3, wherein the distance between two parallel rectangular bars of the vertical segment is greater than the diameter of the pin (10).
10. The apparatus as claimed in claim 3, wherein horizontal segment (7b) of the slider (7) is kept in position by a slide support holder (8).
11. The apparatus as claimed in claim 1, wherein the apparatus is placed on a platform (9), the metallic collector is placed on a support stand (15), electric motor (13) is placed on a support stand (14).
12. A method to operate apparatus as claimed in any of the preceding claims, said method comprises the steps of:
- feeding of a polymer solution to the spinneret (1) through the supply pipe (2),
- rotating circular crank disc (6) by the electric motor (13) at desired frequency (rpm), causing controlled vertical movement of vertical segment and corresponding horizontal to-and-fro movement of horizontal segment, leading to controlled horizontal to-and-fro movement of the spinneret,
- creating specific high electric field between spinneret and metallic collector, causing repulsive force among the particles of polymer solution at the spinneret tip (1c),
- extrusion of polymer solution of charged particles from orifice at the tip of the spinneret (1) creating a cone shaped electrospinning region (3),
- deposition of the fiber mat (5) over a pre-determined area on the metallic collector (4)
wherein magnitude of the to-and-fro movement of the horizontal segment (7b) can be controlled by selecting the different position of the pin (10) on the disc as shown pin holes (11) on the disc, leading to controlling corresponding to-and-fro movement of the spinneret (1), thereby enabling deposition of the fiber mat (5) of desired and uniform thickness on the pre-determined area of the collector (4).
13. The method as claimed in claim 12, wherein said method enables deposition of fiber mat (5) of desired and uniform thickness over the pre-determined area on the metal collector (4).
14. An electrospun fiber producing apparatus comprising an electrospinning device coupled with scotch yoke mechanism and a method to operate thereof, substantially as hereinbefore described with reference to the accompanying specification, drawings and any of the preceding claims.