Systems for producing fibers and related methods

Abstract

Provided herein is a system for producing fibers. The system includes a centrifugal spinning apparatus including a centrifugal spinning device configured to produce one or more fibers in a radial direction; a fiber collection apparatus including a collection element positioned relative to the centrifugal spinning apparatus and a collection surface on the collection element, wherein the collection surface is arranged and disposed to contact the one or more fibers produced by the centrifugal spinning apparatus; and a drive mechanism configured to move at least a portion of at least one of the centrifugal spinning apparatus and the fiber collection apparatus in a transverse direction with respect to the other. Also provided herein is a method of producing fibers using the system.

Description

[0001] SYSTEMS FOR PRODUCING FIBERS AND RELATED METHODS

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 537,345, filed September 8, 2023, which application is incorporated herein by reference in its entirety.

[0004] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0005] This invention was made with government support under grant number(s) W91 INF-17-2-0227 awarded by the Army Research Laboratory and 1653329 awarded by the National Science Foundation. The government has certain rights in the invention.

[0006] BACKGROUND

[0007] Centrifugal fiber spinning is a method for producing small diameter nanofibers by applying a centrifugal force to a polymer solution. A traditional centrifugal spinner includes a spinneret, which is essentially a cup containing several holes or orifices, surrounded by a series of collection posts spaced the same distance from the spinneret. The spinneret, containing the polymer solution, is accelerated to a high rotational speed to produce the fibers. The centrifugal force generated by the rotating spinneret forces the polymer solution out through the spinneret’s orifices, creating a long fiber chain. The fiber chain continues to travel outward until reaching the static collection posts, thereafter depositing on the collection posts.

[0008] Centrifugal spinning can produce a large amount of fiber in a short amount of time. However, the capacity to scale up the throughput of centrifugally spun fibers using static collection posts is limited. For example, fiber can build up and form a dense “ring” on static collection posts within minutes. This buildup of fibers on the collection posts can cause the fibers to gradually deposit in closer proximity to the spinneret, which is actively producing / extruding fiber during this time. Eventually, the spinneret can come in contact with the fiber ring and remove (or rip) the collected fiber off the collection posts. As such, the centrifugal spinning process needs to be stopped to collect the fiber “ring” (e.g., to prevent further buildup), which limits fiber production throughput. i Accordingly, there remains a need in the art for a system that improves fiber processing and / or mitigates fiber buildup. The present invention meets this need.

[0009] SUMMARY

[0010] In one aspect system for producing fibers includes a centrifugal spinning apparatus including a centrifugal spinning device configured to produce one or more fibers in a radial direction; a fiber collection apparatus including a collection element positioned relative to the centrifugal spinning apparatus and a collection surface on the collection element, wherein the collection surface is arranged and disposed to contact the one or more fibers produced by the centrifugal spinning apparatus; and a drive mechanism configured to move at least a portion of at least one of the centrifugal spinning apparatus and the fiber collection apparatus in a transverse direction with respect to the other.

[0011] In some embodiments, the centrifugal spinning device includes a spinning cup or a spinneret. In some embodiments, the centrifugal spinning device is configured to spin about an axis of rotation.

[0012] In some embodiments, the drive mechanism is configured to move at least a portion of the fiber collection apparatus linearly along a direction parallel to the axis of rotation.

[0013] In some embodiments, the fiber collection apparatus further comprises a collection substrate. In some embodiments, the collection substrate is moveably positioned between the centrifugal spinning apparatus and the collection surface. In some embodiments, the system further includes a supply roll configured to supply the collection substrate and a collection roll configured to collect the collection substrate with the one or more fibers positioned thereon.

[0014] In some embodiments, the collection element comprises a rotating collection element; the collection surface comprises a track; and the drive mechanism is configured to rotate the track about the rotating collection element. In some embodiments, the rotating collection element comprises a plurality of rotating collection elements. In some embodiments, the rotating collection element orients the track with a vertical portion facing the centrifugal spinning apparatus. In some embodiments, the rotating collection element orients the track with a first portion and a second portion, the first portion and the second portion being at different angles with respect to the centrifugal spinning apparatus. In some embodiments, the first portion is substantially parallel to an axis of rotation of a centrifugal spinning device of the centrifugal spinning apparatus. In some embodiments, the second portion is angled between 1° and 90° with respect to the axis of rotation. In some embodiments, the system further includes a cutting mechanism. In some embodiments, the cutting mechanism is a blade disposed at a distal end the track.

[0015] In some embodiments, the system further includes a heating device configured to carbonize fibers.

[0016] In some embodiments, the collection element is disposed radially around the centrifugal spinning apparatus.

[0017] Also provided is a system for producing fibers including a centrifugal spinning apparatus including a centrifugal spinning device configured to produce one or more fibers in a radial direction; a fiber collection apparatus including a collection element positioned relative to the centrifugal spinning apparatus, a collection surface on the collection element; and a collection substrate moveably positioned between the centrifugal spinning apparatus and the collection surface; wherein the collection substrate is arranged and disposed to contact the one or more fibers produced by the centrifugal spinning apparatus. In some embodiments, the system further includes a supply roll configured to supply the collection substrate and a collection roll configured to collect the collection substrate with the one or more fibers positioned thereon.

[0018] Also provided is a method of producing fibers using the system according to any of the embodiments disclosed herein, the method including the steps of (a) positioning the collection element relative to the centrifugal spinning apparatus; (b) providing a solution to the centrifugal spinning apparatus; (c) spinning the centrifugal spinning device such that the solution is expelled from the centrifugal spinning device towards the collection surface; and (d) transversely moving at least one of the centrifugal spinning apparatus, the collection element, and the collection surface; wherein the expelled solution produces the fiber on the collection surface. In some embodiments, the method further includes (e) removing collected fiber from the collection apparatus using a collection roll. In some embodiments, the method further includes (f) post-processing collected fiber.

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures. Unless stated or understood otherwise, like reference characters denote corresponding parts throughout the several views. Accordingly, to simplify the explanation, substantially the same or similar content may be omitted in connection with certain figures.

[0021] It is emphasized that, according to common practice, the various features of the drawing are not to scale. On the contrary, the dimensions of the various features may be arbitrarily deformed or reduced for clarity.

[0022] FIGS. 1 A-1B illustrate a system for producing fibers, in accordance with an exemplary embodiment of the present disclosure.

[0023] FIG. 2 illustrates a collection rack for collecting produced fibers, in accordance with an exemplary embodiment of the present disclosure.

[0024] FIGS. 3 A-3B illustrate a collection rack for collecting produced fibers, in accordance with an exemplary embodiment of the present disclosure.

[0025] FIGS. 4A-4B illustrate a system for producing fibers, in accordance with an exemplary embodiment of the present disclosure.

[0026] FIGS. 5A-5D illustrate various views of a system for producing fibers including a plurality of tracks, in accordance with an exemplary embodiment of the present disclosure. (A) Perspective view of the system for producing fibers including a plurality of tracks. (B) Enlarged perspective view of a portion of the system for producing fibers including a plurality of tracks. (C) Top view of a system for producing fibers including a plurality of tracks. (D) Perspective view of a track used in the system.

[0027] FIGS. 6A-6C illustrate various views of a system for producing fibers including a plurality of tracks, in accordance with an exemplary embodiment of the present disclosure. (A) Perspective view of the system. (B) Cross-sectional perspective view of the system. (C) Cross-sectional side view of the system.

[0028] FIG. 7 illustrates a flow diagram of methods of producing fibers, in accordance with an exemplary embodiment of the present disclosure.

[0029] DETAILED DESCRIPTION OF THE INVENTION

[0030] Definitions

[0031] The instant invention is most clearly understood with reference to the following definitions.

[0032] As used herein, the singular form "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless specifically stated or obvious from context, as used herein, the term "about" is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. "About" can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from context, all numerical values provided herein are modified by the term about.

[0033] As used in the specification and claims, the terms "comprises," "comprising," "containing," "having," and the like can have the meaning ascribed to them in U.S. patent law and can mean "includes," "including," and the like.

[0034] Unless specifically stated or obvious from context, the term "or," as used herein, is understood to be inclusive.

[0035] Ranges provided herein are understood to be shorthand for all of the values within the range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or sub-range from the group consisting 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 (as well as fractions thereof unless the context clearly dictates otherwise).

[0036] As used herein, a “collection surface” refers to a surface upon which fibers are disposed. In some embodiments, a collection surface can be a single and continuous surface. In some embodiments, the collection surface can be a plurality of surfaces disposed radially. In some embodiments, a collection surface can be defined by a movable belt (e.g., a belt, a driven surface, a conveyor belt, etc.).

[0037] Detailed Description

[0038] Provided herein are systems for producing fibers. As illustrated in FIGS. 1 A-6C, in some embodiments, the system 100 includes a centrifugal spinning apparatus 110 configured to produce one or more fibers and a fiber collection apparatus 120 configured to collect fibers produced by the centrifugal spinning apparatus 110. For example, in some embodiments, the centrifugal spinning apparatus 110 includes a centrifugal spinning device 111 (e.g., a spinning cup, a spinneret, etc.) arranged and disposed to rotate about an axis of rotation 140 and produce the one or more fibers in a radial or substantially radial direction (e.g., perpendicular or substantially perpendicular to the axis of rotation 140). In such embodiments, the collection apparatus 120 is positioned relative to the centrifugal spinning apparatus 110 to collect (e.g., contact or receive) the one or more fibers as they are produced from the centrifugal spinning device 111. The positioning of the collection apparatus 120 may include any suitable arrangement for collecting the fiber(s), such as, but not limited to, around or substantially around the centrifugal spinning apparatus 110, including circumferentially or substantially circumferentially around centrifugal spinning apparatus 110. The system 110 may be configured to produce any suitable fiber, such as, but not limited to, nanofibers, polymer fibers spun from solution, polymer fiber spun from a melt, polymer materials with polymer or non-polymer fillers, ceramic materials and precursors, carbon precursors, and gels. In some embodiments, the fibers include a diameter of between 10 and 5,000 nm, between 10 and 4,000 nm, between 10 and 3,000 nm, between 10 and 2,000 nm, between 10 and 1,000 nm, between 10 and 500 nm, or any suitable combination, subcombination, range, or sub-range thereof.

[0039] In some embodiments, at least a portion of the centrifugal spinning apparatus 110 is moveable relative to at least a portion of the fiber collection apparatus 120, and / or vice versa. In such embodiments, during production of the fiber, the system 100 is configured to move at least a portion of the centrifugal spinning apparatus 110 and / or at least a portion of the fiber collection apparatus 120 relative to the other. For example, the movement may include moving at least a portion of the centrifugal spinning apparatus 110 relative to a fixed fiber collection apparatus 120, moving at least a portion of the fiber collection apparatus 120 relative to a fixed centrifugal spinning apparatus 110, or moving both at least a portion of the centrifugal spinning apparatus 110 and at least a portion of the fiber collection apparatus 120 relative to each other. This movement may be in any suitable direction to shift the location of fiber collection on the fiber collection apparatus 120, such as, but not limited to, transverse, linearly, vertically, or any other suitable direction. As will be understood by those skilled in the art, when moving at least a portion of both the centrifugal spinning apparatus 110 and the fiber collection apparatus 120 relative to each other, the movement must be in different directions and / or at different speed in order to shift the location of fiber deposition / collection.

[0040] The centrifugal spinning apparatus 110 and / or the fiber collection apparatus 120 may be arranged in any suitable manner for shifting the location of fiber collection on the fiber collection apparatus 120. For example, referring to FIGS. 1 A-3B, in some embodiments, the system 100 includes a moveable collection element system 101. In such embodiments, the fiber collection apparatus 120 includes a collection element 121 having a collection surface 122 and guide holes 124. The guide holes 124 extend throughout a length of the collection element 121, and correspond to guide poles 123 extending from a mounting surface 150. In such embodiments, the guide poles 123 are inserted into the guide holes 124, such that the collection element 121 is moveably positioned relative to the centrifugal spinning apparatus 110. In some embodiments, when positioned relative to the centrifugal spinning apparatus 110, the collection surface 122 surrounds or substantially surrounds the centrifugal spinning device 111. Additionally or alternatively, the guide holes 124 can be formed in the centrifugal spinning apparatus 110, such that the centrifugal spinning apparatus 110 is moveable relative to the fiber collection apparatus 120.

[0041] As will be appreciated by those skilled in the art, although shown primarily with 4 guide poles 123 and four corresponding guide holes 124, the disclosure is not so limited and may independently include any other suitable number of guide poles and / or guide holes. Additionally, as will also be appreciated by those skilled in the art, the fiber collection apparatus 120 and / or centrifugal spinning apparatus 110 is not limited to the guide poles 123 and guide holes 124, and may include any other suitable arrangement for supporting / guiding movement relative to the mounting surface 150 and / or centrifugal spinning apparatus 110. Additionally or alternatively, in some embodiments, the fiber collection apparatus 120 may be configured to rotate about the same axis as the centrifugal spinning device 111 (e.g., with slots / grooves on external guide poles, with rotating guide poles mounted to a rotating platform, etc.).

[0042] The collection element 121 and / or the centrifugal spinning apparatus 110 of the moveable collection element system 101 may be moved along the guide poles 123 and / or relative to the centrifugal collection apparatus 110 by any suitable mechanism, such as, but not limited to, a drive mechanism 130. In some embodiments, for example, the drive mechanism 130 includes a motor 131 configured to engage one or more pinions 133. The pinions 133, in turn, are configured to engage a rack 125 formed on or secured to the collection element 121 and / or the centrifugal spinning apparatus 110. Accordingly, when the motor 131 is activated, it turns the pinions 133, which engage the rack 125 to move the collection element 121 and / or the centrifugal spinning apparatus 110 in a transverse direction with respect to the other. In some embodiments, this movement adjustably positions the centrifugal spinning device 111 relative to any desired portion of the collection surface 122.

[0043] Movement of the collection element 121 relative to the centrifugal spinning apparatus 110 is illustrated in FIGS. 1 A-B. More specifically, FIG. 1 A shows the collection element 121 in a first position (e.g., a lower position along the “Z-axis” / vertical axis of travel). In this position, the centrifugal spinning device I l l is positioned near a top of the collection surface 122. FIG. IB, on the other hand, shows the collection element 121 in a second position (e.g., an upper position along the “Z-axis” / vertical axis of travel) after having been moved by the drive mechanism 130. In this position, the centrifugal spinning device 111 is positioned near a bottom of the collection surface 122. Accordingly, as will be appreciated by those skilled in the art, when the collection element 121 is moved from the first position to the second position while the fiber is being produced by the centrifugal spinning device 111, the fiber will be deposited over the entire length or substantially the entire length of the collection surface 122. For example, FIGS. 3A-B show photographs illustrating a plurality of fibers 301 deposited on the collection surface 122 of the collection element 121 using the system 101.

[0044] Referring now to FIG. 2, the collection element 121 is illustrated having been removed from fiber collection apparatus 120. In some embodiments, the collection element 121 includes a substantially cylindrical structure with alternating posts and open portions extending between circular top and bottom portions. In some embodiments, the collection element 121 resembles a cage and / or includes features similar to collection posts (e.g., the posts between the circular top and bottom portions discussed above). In some embodiments, the features of the collection element 121 are positioned equally distant from the axis of rotation 140 of the centrifugal spinning device 111 positioned within the collection element 121. Although various specific embodiments of the collection element are discussed herein, as will be appreciated by those skilled in the art, the collection element 121 is not so limited and may include any other suitable shape for collecting fibers produced by the centrifugal spinning apparatus 110. The collection element 121 may be made from any suitable material and using any suitable manufacturing technique. For example, in some embodiments, the collection element 121 is made with rigid materials (e.g., plastic, additively manufactured material, metal, composite, etc.). Additionally or alternatively, in some embodiments, the collection element 121 can be made with flexible materials. In some embodiments, the collection element 121 is hinged. For example, the collection element 121 may be hinged to allow the collection element 121 to be opened.

[0045] In some embodiments, the fiber collection apparatus 120 includes a collection substrate 400 positioned over the collection surface 122 of the collection element 121. In such embodiments, the collection substrate 400 is positioned between the centrifugal spinning apparatus 110 and the collection surface 122, such that the fibers produced by the centrifugal spinning apparatus 110 are deposited directly on the collection substrate 400 instead of the collection surface 122. In some embodiments, the collection substrate 400 is provided without the drive mechanism 130. In such embodiments, the centrifugal spinning apparatus 110 produces a thin strip of fiber on the collection substrate 400. Alternatively, in some embodiments, the collection substrate 400 is moveable with respect to the collection surface 122. For example, in some embodiments, as illustrated in FIGS. 4A-B, the collection substrate 400 includes a backing 401 (e.g., a thin sheet, a tape, etc.) that is fed from a supply roll 411 (e.g., a roll of a “backing”), along the collection surface 122, and to a collection roll 412. In such embodiments, when fed from the supply roll 411 and / or wound at the collection roll 412, the collection substrate 400 translates across the collection surface 122.

[0046] The collection substrate 400 may be fed into and / or removed from the collection element 121 (e.g., over the collection surface 122) through any suitable manner. For example, in some embodiments, as best illustrated in FIG. 4B, the collection element 121 includes one or more slots 413 through which the collection substrate 400 may be fed from the supply roll 411 into the collection element 121 and / or from within the collection element 121 to the collection roll 412. Additionally or alternatively, in some embodiments, the supply roll 411 and the collection roll 412 can be configured to move (e.g., in a transverse direction, a vertical direction, etc.) in conjunction with the collection element 121. In some embodiments, the collection roll 412 can wind itself up (e.g., manually, using a motor, etc.) and translate vertically. In such embodiments, the entire surface area (or at least the majority) of the collection substrate 400 can be covered with centrifugally spun fibers.

[0047] In some embodiments, the collection roll 412 is configured to be wound during a centrifugal fiber spinning process and / or while the collection element 121 translates (e.g., vertically). For example, in some embodiments, the collection substrate 400 can be translated / collected (e.g., laterally, perpendicular to the axis of rotation of the centrifugal spinning apparatus, perpendicular to a circumference defined by the collection element, etc.) when the collection element 121 reaches a predefined translational position (e.g., end of travel, a maximum vertical position, a minimum vertical position, a maximum lateral position, a minimum lateral position, etc.) and / or when a predefined amount of fiber has been generated. In some embodiments, the predetermined translation position includes the end point of a full transverse movement (e.g., a vertical movement up, a vertical movement down, or a combination thereof). In such embodiments, after reaching the predetermined translational position, the collection substrate 400 is wound (e.g., moved horizontally) to collected the deposited fiber(s) from within the collection element 121. Additionally or alternatively, the frequency of collection can be selected to provide a desired amount of fiber deposition. For example, in some embodiments, the frequency of collection can be selected such that the surface area of the collection substrate 400 is substantially or completely covered with the produced fibers prior to the collection / winding of the collection substrate 400. After collecting the fiber(s), the collection element 121 can make another full transverse movement, allowing collection over a “fresh” surface (z.e., a surface without collected fibers) before repeating the winding / collection of the collection substrate 400. In some embodiments, a portion of the fibers deposited on the collection substrate 400 can be cut before being collected / winding the collection roll 412. For example, in some embodiments, deposited fibers span a gap between inlet and outlet sections of the collection substrate 400 (e.g., in the area of the one or more slots 413 through which the collection substrate 400 enters / exits the interior of the collection element 121). The portion of the fibers spanning this gap may be cut, such that the cut fiber strands can be removed with the collection substrate 400 when collection substrate is collected / the collection roll 412 is wound (e.g., in between vertical movements). This cutting / removing of the fibers allows another portion of the collection substrate 400, without any fibers, to be provided. The fibers may be cut with any suitable cutting mechanism, such as, but not limited to, a mechanical cutter (e.g., blade), a laser, a heating element to melt a portion of the fibers, any other suitable cutting mechanism, or a combination thereof.

[0048] The collecting / winding of the collection substrate 400 described herein simultaneously provides quick collection of the deposited fiber and a clean surface for continued deposition of new fiber, enabling the centrifugally spun fiber to be collected and packaged in a roll-to-roll fashion. Accordingly, in some embodiments, the collection substrate 400 improves throughput of the centrifugal spinning process (e.g., by requiring less user input associated with halting a spinning process to collect produced fibers). Additionally or alternatively, in some embodiments, the collection substrate 400 enables production of centrifugally spun fibers for longer periods of time without user intervention or interruption (e.g., due to fiber build-up or fiber tearing, as seen when using static collection posts).

[0049] In some embodiments, in addition to or instead of collection element 121 being moveable, the collection surface 122 of the collection apparatus 120 is moveable. For example, in some embodiments, as illustrated in FIGS. 5A-D, the system 100 includes a vertical track system 501. In the vertical track system 501, the collection element 121 includes one or more rotating collection elements 521, and the collection surface 122 of each rotating collection element 521 includes a track 522. In some embodiments, a plurality of the rotating collection elements 521 are positioned around (e.g., radially around) the centrifugal spinning apparatus 110, such that the tracks 522 collectively define a moveable surface surrounding or substantially surrounding the centrifugal spinning apparatus 110. In such embodiments, the track 522 or tracks 522 are configured to move as the fiber is being formed, such that the formed fiber is deposited over different portions of the track(s) 522.

[0050] The collection elements 521 include any suitable configuration for rotating the corresponding tracks 522. For example, as best seen in FIG. 5D, in some embodiments, the collection elements 521 include pulleys 525 configured to orient and move the corresponding tracks 522. The track(s) can be moved by any suitable mechanism, such as, but not limited to, a track drive mechanism 530. In some embodiments, the track drive mechanism 530 includes a motor coupled directly to one or more of the rotating collection elements 521. In some embodiments, the track drive mechanism 530 is integral with one or more of the rotating collection elements 521. In some embodiments, each of the rotating collection elements 521 includes a dedicated track drive mechanism 530. Alternatively, in some embodiments, a single (integral or separate) track drive mechanism 530 is coupled to each of the rotating collection elements 521. Each of the tracks 522 may be configured to rotate at the same speed, or one or more of the tracks 522 may be configured to rotate at a different speed. For example, one or more track drive mechanisms 530 may be programmed to provide a different rotational speed, or multiple track drive mechanisms 530 may be coupled and / or programmed to rotate the tracks 522 at the same speed. Additionally or alternatively, a single track drive mechanism 530 may be coupled to multiple tracks 522, providing each of the coupled tracks 522 with the same rotational speed.

[0051] Each track 522 and / or the surface of each track 522 can be made with any suitable material for collecting and / or translating the fibers. Suitable materials include, but are not limited to, rubber (e.g., a rubber belt), plastic (e.g., a plastic timing belt), or any other material suited to move (e.g., carry, translate, etc.) the fibers 503. Additionally or alternatively, each track 522 can include any suitable width, thickness, shape, and / or orientation. For example, in some embodiments, as illustrated in FIGS. 5A-D, the rotating collection elements 521 orient the respective tracks 522 with a vertical or substantially vertical portion facing the centrifugal spinning apparatus 110. As also illustrated in FIGS. 5 A-D, in some embodiments, the tracks 522 are narrower, creating open space between tracks 522 / rotating collection elements 521.

[0052] Still referring to FIGS. 5A-D, in some embodiments, fibers 503 can be collected as the tracks 522 translate towards the top of the rotating collection elements 521 (e.g., along the “Z-axis”) and / or away from the centrifugal spinning apparatus 110. For example, fibers 503 can be collected as individual bundles through the use of a cutting mechanism 523 (e.g., blades, X-ACTO blades, etc.) between one or more pairs of adjacent tracks 522. In some embodiments, the cutting mechanism 523 is disposed at a distal end of at least one of the tracks 522. For example, in some embodiments, as illustrated in FIGS. 5A-D, each cutting mechanism 523 is disposed at a distal end of each track 522.

[0053] Turning to FIGS. 6A-6C, in some embodiments, the system 100 includes a varied angle track system 601. Similar to the vertical track system 501, the varied angle track system 601 includes the fiber collection apparatus 120 with one or more rotating collection elements 521 positioned around the centrifugal spinning apparatus 110. Each of the rotating collection elements 521 also includes a track 522 forming the collection surface 122. However, in some embodiments, the tracks 522 of the varied angle track system 601 include a first portion 622 and a second portion 623 facing the centrifugal spinning apparatus 110, the first portion 622 and the second portion 623 having different angles with respect to the centrifugal spinning apparatus 110. For example, in some embodiments, the first portion 622 is oriented vertically with respect to the centrifugal spinning apparatus 110 (e.g., parallel or substantially parallel to the axis of rotation 140), and the second portion 623 is angled with respect to the centrifugal spinning apparatus 110 (e.g., up and away from). The tracks 522 may be driven by any suitable mechanism, such as, but not limited to, the drive mechanism 530 according to any of the embodiments disclosed herein.

[0054] In some embodiments, the angled portion of the tracks 522 in the varied angle track system 601 is configured to allow fibers to be post-drawn during the collection process. For example, as illustrated in FIGS. 6A-C, each respective second portion 623 forms a “gap” with an adjacent second portion 623. This gap between the second portions 623 of the tracks 522 increases as the tracks 522 translate away from the centrifugal spinning apparatus 110. Fibers spanning between tracks 522 are stretched as they travel through the increasing gap. In some embodiments, this stretching, or post-drawing, improves alignment and / or mechanical strength of the fibers while reducing fiber diameter. The ratio of final fiber diameter to initial fiber diameter, known as the draw ratio, can be modified as needed by adjusting the angle of the second portion 623 with respect to the first portion 622 and / or the centrifugal spinning apparatus 110. Suitable angles include, but are not limited to, between 1° and 90°, between 2° and 90°, between 3° and 90°, between 4° and 90°, between 5° and 90°, between 10° and 90°, between 15° and 90°, between 20° and 90°, between 25° and 90°, between 30° and 90°, between 35° and 90°, between 40° and 90°, between 45° and 90°, or any combination, subcombination, range, or sub-range thereof. In some embodiments, as described above, the fibers can be collected as individual bundles through the use of a cutting mechanism (e.g., a blade, an X-ACTO blade) protruding through the gaps in between each pair of adjacent tracks 522.

[0055] In the system 100 according to any of the embodiments disclosed herein, the travel speed of the centrifugal spinning apparatus 110, the fiber collection apparatus 120, the collection element 121, and / or the collection surface 122 and / or frequency of collection can be adjusted to provide a desired density of fibers. For example, in some embodiments, the drive mechanism 130 / 530 according to any of the embodiments disclosed herein (e.g., a stepper motor) can be configured to move the centrifugal spinning apparatus 110, the fiber collection apparatus 120, the collection element 121, and / or the collection surface 122 in a predetermined movement profile (e.g., constant movement profile, constant velocity, constant acceleration, a predetermined location profile, a predetermined velocity profile, a predetermined acceleration profile, etc.). In some embodiments, the predetermined movement profile includes a minimum movement speed (e.g., a minimum vertical travel speed) to prevent “fiber tearing.” The minimum movement speed can be based on one or more polymer solution dispensing rates.

[0056] By adjusting the travel speed of the vertical translation of the system 100 according to one or more of the embodiments disclosed herein, the centrifugally spun fibers formed and collected therefrom can be packaged as a sheet at a desired density. Additionally or alternatively, in contrast to static collection posts, where fibers are continuously deposited and built on top of each other, the system disclosed herein is capable of depositing and collecting fibers over a wide surface area.

[0057] In some embodiments, the system 100 according to any of the embodiments described herein includes a heating device 540 (e.g., heaters, small heaters, etc.). In such embodiments, the heater me be arranged and / or configured to carbonize the fibers after the fibers have been collected. The selection and placement of the heaters can be selected based on the particular polymer solution used, as will be appreciated by those skilled in the art. For example, a heater can be used in connection with polyacrylonitrile (PAN) fibers, which can serve as a precursor to a carbon nanofiber.

[0058] As will be appreciated by those skilled in the art, although certain features are discussed with respect to specific embodiments, unless explicitly stated otherwise, the disclosure is not so limited and the various features can be combined with any other embodiment. For example, the movement of the centrifugal spinning apparatus 110 described in some embodiments can be combined with the movement of the fiber collection apparatus 120, collection element 121, and / or collection surface 122 discussed in any of the other embodiments. Additionally or alternatively, in some embodiments, the centrifugal spinning device 111 can be modified. For example, the centrifugal spinning device 111 can have a different number of orifices with different properties (e.g, different shapes, diameters, placement, surface roughness, sharpness, shearing properties, etc.). In another example, the centrifugal spinning device 111 can be modified to operate at higher or lower rotational speeds.

[0059] Also provided herein are methods of producing fibers using the system according to one or more of the embodiments disclosed herein. For example, FIG. 7 shows a flow diagram illustrating methods of producing fibers (e.g., using various systems described herein), in accordance with exemplary embodiments of the present invention. As is understood by those skilled in the art, certain steps included in the flow diagrams may be omitted; certain additional steps may be added; and the order of the steps may be altered from the order illustrated.

[0060] As understood by those skilled in the art, centrifugal nanofiber spinning is a process for producing small diameter fibers (e.g., nanofibers, centrifugally spun fibers from a polymer solution, etc.). The spinning process involves dispensing a solution into the centrifugal spinning apparatus 110 having the centrifugal spinning device 111 with at least one orifice formed in an outer wall thereof (e.g., a spinning cup, a spinneret, etc.), and accelerating the centrifugal spinning device 111 to a high rotational speed. The high rotational speed forces the solution to an inner surface of the outer wall of the centrifugal spinning device 111 and into the orifice(s). The orifice(s) have a small diameter that stretches the solution into a long chain. The solution then exits the centrifugal spinning device 111 through the orifice(s) and travels outward (e.g., radially) towards a collection site (e.g, a collection surface, a plurality of collection posts, etc.).

[0061] Referring specifically to FIG. 7, at Step 700, the centrifugal spinning apparatus 110 including the centrifugal spinning device 111 configured to produce fibers is provided. At Step 702, the collection apparatus 120 according to any of the embodiments disclosed herein is disposed such that at least a portion of the collection surface 122 receives one or more fibers produced by the centrifugal spinning device 111. At Step 704, the centrifugal spinning device 111 is spun such that a fiber is produced and expelled towards the collection surface 122. The solution used in the nanofiber spinning process may include, but is not limited to, a polymer solution, a viscous polymer solution, a slow-moving polymer solution, a polymer solution including polyacrylonitrile dissolved in dimethylformamide, or any other solution suitable for forming a desired nanofiber. Each solution includes a solvent that evaporates while the solution travels outward from the device. The evaporation of this solvent results in the formation of a fiber (e.g., a nanofiber). As will be appreciated by those skilled in the art, the composition of the solution and concentration of the solvent may be selected to produce a desired fiber under various spinning conditions. At Step 706, the fiber collection apparatus 120, the collection element 121, and / or the collection surface 122 is moved with respect to the centrifugal spinning apparatus 110 and / or vice versa.

[0062] In some embodiments, the method further includes the step of collecting the fiber using a collection substrate 400 (e.g., collection roll 412). In some embodiments, the method further includes the step of post-processing collected fiber using one of more of a heating device, a cutting mechanism, a plurality of tracks, and a collection roll.

[0063] EQUIVALENTS

[0064] Although preferred embodiments of the invention have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

[0065] INCORPORATION BY REFERENCE

[0066] The entire contents of all patents, published patent applications, and other references cited herein are hereby expressly incorporated herein in their entireties by reference.

Claims

CLAIMS1. A system for producing fibers comprising: a centrifugal spinning apparatus including a centrifugal spinning device configured to produce one or more fibers in a radial direction; a fiber collection apparatus including: a collection element positioned relative to the centrifugal spinning apparatus; and a collection surface on the collection element; wherein the collection surface is arranged and disposed to contact the one or more fibers produced by the centrifugal spinning apparatus; and a drive mechanism configured to move at least a portion of at least one of the centrifugal spinning apparatus and the fiber collection apparatus in a transverse direction with respect to the other.

2. The system of claim 1, wherein the centrifugal spinning device includes a spinning cup or a spinneret.

3. The system of claim 3, wherein the drive mechanism is configured to move at least a portion of the fiber collection apparatus linearly along a direction parallel to an axis of rotation of the centrifugal spinning device.

4. The system of claim 1, wherein the fiber collection apparatus further comprises a collection substrate.

5. The system of claim 4, wherein the collection substrate is moveably positioned between the centrifugal spinning apparatus and the collection surface.

6. The system of claim 5, further comprising: a supply roll configured to supply the collection substrate; and a collection roll configured to collect the collection substrate with the one or more fibers positioned thereon.

7. The system of claim 1, wherein:the collection element comprises a rotating collection element; the collection surface comprises a track; and the drive mechanism is configured to rotate the track about the rotating collection element.

8. The system of claim 7, wherein the rotating collection element comprises a plurality of rotating collection elements.

9. The system of claim 7, wherein the rotating collection element orients the track with a vertical portion facing the centrifugal spinning apparatus.

10. The system of claim 7, wherein the rotating collection element orients the track with a first portion and a second portion, the first portion and the second portion being at different angles with respect to the centrifugal spinning apparatus.

11. The system of claim 10, wherein the first portion is substantially parallel to an axis of rotation of a centrifugal spinning device of the centrifugal spinning apparatus.

12. The system of claim 11, wherein the second portion is angled between 1° and 90° with respect to the axis of rotation.

13. The system of claim 7, further comprising a cutting mechanism.

14. The system of claim 13, wherein the cutting mechanism is a blade disposed at a distal end the track.

15. The system of claim 1, further comprising a heating device configured to carbonize fibers.

16. The system of claim 1, wherein the collection element is disposed radially around the centrifugal spinning apparatus.

17. A system for producing fibers comprising:a centrifugal spinning apparatus including a centrifugal spinning device configured to produce one or more fibers in a radial direction; and a fiber collection apparatus including: a collection element positioned relative to the centrifugal spinning apparatus; a collection surface on the collection element; and a collection substrate moveably positioned between the centrifugal spinning apparatus and the collection surface; wherein the collection substrate is arranged and disposed to contact the one or more fibers produced by the centrifugal spinning apparatus.

18. The system of claim 17, further comprising: a supply roll configured to supply the collection substrate; and a collection roll configured to collect the collection substrate with the one or more fibers positioned thereon.

19. A method of producing fibers using the system according to any one of claims 1-16, comprising the steps of:(a) positioning the collection element relative to the centrifugal spinning apparatus;(b) providing a solution to the centrifugal spinning apparatus;(c) spinning the centrifugal spinning device such that the solution is expelled from the centrifugal spinning device towards the collection surface; and(d) transversely moving at least one of the centrifugal spinning apparatus, the collection element, and the collection surface; wherein the expelled solution produces the fiber on the collection surface.

20. The method of claim 18, further comprising at least one of:(e) removing collected fiber from the collection apparatus using a collection roll; or(f) post-processing collected fiber.

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