U.S. patent application number 14/324390 was filed with the patent office on 2015-01-15 for method of making a device for use in a microfiber and/or nanofiber producing system.
This patent application is currently assigned to FibeRio Technology Corporation. The applicant listed for this patent is FibeRio Technology Corporation. Invention is credited to Stephen Kay, Roger Lipton, Ed Peno.
Application Number | 20150013141 14/324390 |
Document ID | / |
Family ID | 46639146 |
Filed Date | 2015-01-15 |
United States Patent
Application |
20150013141 |
Kind Code |
A1 |
Peno; Ed ; et al. |
January 15, 2015 |
METHOD OF MAKING A DEVICE FOR USE IN A MICROFIBER AND/OR NANOFIBER
PRODUCING SYSTEM
Abstract
Described herein are apparatuses and methods of creating fibers,
such as microfibers and nanofibers. The methods discussed herein
employ centrifugal forces to transform material into fibers.
Apparatuses that may be used to create fibers are also described.
Described herein are fiber producing devices that have various
types of outlet elements coupled to the fiber producing device.
Inventors: |
Peno; Ed; (Mission, TX)
; Lipton; Roger; (Austin, TX) ; Kay; Stephen;
(Austin, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FibeRio Technology Corporation |
McAllen |
TX |
US |
|
|
Assignee: |
FibeRio Technology
Corporation
McAllen
TX
|
Family ID: |
46639146 |
Appl. No.: |
14/324390 |
Filed: |
July 7, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13368090 |
Feb 7, 2012 |
8778240 |
|
|
14324390 |
|
|
|
|
61440219 |
Feb 7, 2011 |
|
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Current U.S.
Class: |
29/525.01 ;
29/428 |
Current CPC
Class: |
D01D 5/08 20130101; B29C
48/04 20190201; D01D 4/022 20130101; D01D 4/02 20130101; D01D 5/18
20130101; Y10T 29/49826 20150115; D01D 5/0076 20130101; Y10T
29/49947 20150115; D01D 1/04 20130101; D01D 5/0007 20130101 |
Class at
Publication: |
29/525.01 ;
29/428 |
International
Class: |
D01D 4/02 20060101
D01D004/02 |
Claims
1-1235. (canceled)
1236. A method of making a device for use in a microfiber and/or
nanofiber producing system, the method comprising: obtaining a
first member, the first member comprising a first member coupling
surface, the first member coupling surface comprising one or more
grooves extending along the width of the first member coupling
surface; obtaining a second member, the second member comprising a
second member coupling surface and a coupling member, the second
member coupling surface comprising one or more grooves extending
along the width of the second member coupling surface; coupling the
first member coupling surface to the second member coupling surface
to form a body, wherein the first member and the second member
together define an internal cavity of the body; and wherein one or
more grooves of the first member coupling member are substantially
aligned with one or more grooves of the second member coupling
member to form one or more openings extending from the interior
cavity to an outer surface of the body; wherein, during use,
rotation of the body causes material in the body to be passed
through one or more openings to produce microfibers and/or
nanofibers.
1237. The method of claim 1236, wherein the body is
cylindrical.
1238. The method of claim 1236, wherein the first member comprises
a first member opening, wherein material is added to the internal
cavity through the first member opening.
1239. The method of claim 1236, wherein the first member is ring
shaped, wherein material is added to the internal cavity through a
central opening of the ring shaped first member.
1240. The method of claim 1236, further comprising securing the
first member to the second member using one or more fasteners.
1241. The method of claim 1240, further comprising altering the
position of one or more fasteners, wherein a pattern of fibers
produced by the fiber producing device is altered based on the
positions of one or more fasteners.
1242. The method of claim 1236, wherein the first member coupling
surface contacts the second member coupling surface when the first
member is coupled to the second member.
1243. The method of claim 1236, wherein an interior surface of a
sidewall of the internal cavity is angled from a bottom wall toward
one or more of the openings.
1244. The method of claim 1236, wherein an interior surface of a
sidewall of the internal cavity is rounded from a bottom wall
toward one or more of the openings.
1245. The method of claim 1236, further comprising a first
alignment element disposed on the first coupling surface and a
second alignment element disposed on the second coupling surface,
wherein the method further comprises coupling the first alignment
element with the second alignment element to align the first member
with the second member.
1246. The method of claim 1245, wherein one of the first or second
alignment elements comprises a projection extending form the
coupling surface, and wherein the other of the first or second
alignment elements comprises an indentation complementary to the
projection.
1247. The method of claim 1236, wherein the coupling member extends
through the internal cavity and through the first member.
1248. The method of claim 1236, wherein the coupling member is
coupled to an outer surface of the second member, extending away
from the second member.
1249-1351. (canceled)
Description
PRIORITY CLAIM
[0001] The present application is a continuation of U.S. patent
application Ser. No. 13/368,090, filed Feb. 7, 2012, which claims
priority to U.S. Provisional Application No. 61/440,219 filed on
Feb. 7, 2011.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to the field of
fiber production. More specifically, the invention relates to
fibers of micron and sub-micron size diameters.
[0004] 2. Description of the Relevant Art
[0005] Fibers having small diameters (e.g., micrometer ("micron")
to nanometer ("nano")) are useful in a variety of fields from the
clothing industry to military applications. For example, in the
biomedical field, there is a strong interest in developing
structures based on nanofibers that provide scaffolding for tissue
growth to effectively support living cells. In the textile field,
there is a strong interest in nanofibers because the nanofibers
have a high surface area per unit mass that provide light, but
highly wear resistant, garments. As a class, carbon nanofibers are
being used, for example, in reinforced composites, in heat
management, and in reinforcement of elastomers. Many potential
applications for small-diameter fibers are being developed as the
ability to manufacture and control their chemical and physical
properties improves.
[0006] It is well known in fiber manufacturing to produce extremely
fine fibrous materials of organic fibers, such as described in U.S.
Pat. Nos. 4,043,331 and 4,044,404, where a fibrillar mat product is
prepared by electrostatically spinning an organic material and
subsequently collecting spun fibers on a suitable surface; U.S.
Pat. No. 4,266,918, where a controlled pressure is applied to a
molten polymer which is emitted through an opening of an energy
charged plate; and U.S. Pat. No. 4,323,525, where a water soluble
polymer is fed by a series of spaced syringes into an electric
field including an energy charged metal mandrel having an aluminum
foil wrapper there around which may be coated with a PTFE
(Teflon.TM.) release agent. Attention is further directed to U.S.
Pat. Nos. 4,044,404, 4,639,390, 4,657,743, 4,842,505, 5,522,879,
6,106,913 and 6,111,590--all of which feature polymer nanofiber
production arrangements.
[0007] Electrospinning is a major manufacturing method to make
nanofibers. Examples of methods and machinery used for
electrospinning can be found, for example, in the following U.S.
Pat. Nos. 6,616,435; 6,713,011; 7,083,854; and 7,134,857.
SUMMARY OF THE INVENTION
[0008] Described herein are apparatuses and methods of creating
fibers, such as microfibers and nanofibers. The methods discussed
herein employ centrifugal forces to transform material into fibers.
In one embodiment a fiber producing system includes a fiber
producing device and a driver capable of rotating the fiber
producing device. The fiber producing device, in one embodiment,
includes a body having one or more openings and a coupling member,
wherein the body is configured to receive material to be produced
into a fiber; and one or more nozzles coupled to one or more of the
openings, wherein the one or more nozzles comprise a nozzle
orifice. The body of the fiber producing device is couplable to the
driver through the coupling member. During use rotation of the
fiber producing device coupled to the driver causes material in the
body to be passed through one or more openings, into one or more
nozzles, and ejected through one or more nozzle orifices to produce
microfibers and/or nanofibers. In some embodiments, fiber producing
system may be configured to substantially simultaneously produce
microfibers and nanofibers.
[0009] The nozzles of the fiber producing device, in one
embodiment, are removably couplable to the body. Alternatively,
nozzles of the fiber producing device may be an integral part of
the body. A sealing ring may be positioned between one or more of
the nozzles and the body to help maintain a secure fitting between
the nozzle and the body. In one embodiment, the body includes a
locking system used to couple one or more nozzles to the openings,
wherein the locking system locks the coupled nozzles in a
predetermined orientation with respect to the body.
[0010] A nozzle may be removably couplable to a fiber producing
device. Alternatively, a nozzle may be formed on a sidewall of the
body of the fiber producing device such that the body and nozzle
are formed from a single, unitary material. Alternatively, an
opening extending through the sidewall may be formed at the
junction of a pair of joined circular plates that have an alignment
ring or pins. A nozzle may include a nozzle body, the nozzle body
defining an internal cavity and having a proximal end and a distal
end, wherein the proximal end comprises a coupling portion that
allows the nozzle to be coupled to a fiber producing device. The
coupling portion of the nozzle, may, in one embodiment, be a
threaded end which mates with a corresponding threaded portion of
the fiber producing device. A nozzle tip may be coupled to the
distal end of the nozzle body, wherein the nozzle tip has an
internal diameter that is less than the internal diameter of the
nozzle body. The nozzle body includes an opening extending through
a wall of the nozzle body, the nozzle tip being aligned with the
nozzle opening such that material disposed in the nozzle body
passes through the opening into the nozzle tip during use. The
internal diameter of the nozzle tip may be set such that
microfibers and/or nanofibers are produced when material is ejected
through the nozzle tip when the nozzle is coupled to a fiber
producing device.
[0011] In an embodiment, the nozzle tip and the nozzle body are
formed from a single, unitary material. Alternatively, the nozzle
tip may be removably couplable to the nozzle body. A nozzle may
have a length of at least about 2 mm. An internal diameter of the
nozzle tip may be less than about 1 mm. A portion of the interior
wall of the nozzle body is substantially flat and another portion
of the interior wall of the nozzle body is angled and/or rounded
from the flat portion toward the opening formed in the nozzle body.
In one embodiment, a nozzle tip may have an angled and/or rounded
nozzle outlet end. A nozzle may have a non-cylindrical outer
surface. In one embodiment, a nozzle has an outer surface having a
tapered edge. During rotation of the body, gasses contact the
tapered edge of the nozzle, creating a region of negative pressure
on the side opposite to the tapered edge.
[0012] One or more outlet conduits may couple one or more nozzles
to one or more openings. Outlet conduits may have a length to help
set the material diameter before ejection from the nozzle (e.g.,
from 1 mm to about 10 mm, or about 2 mm to about 7 mm, or about 5
mm). Nozzles may include a nozzle orifice.
[0013] The body of the fiber producing device comprises one or more
sidewalls and a top together defining an internal cavity, wherein
one or more openings extend through a sidewall of the body,
communicating with the internal cavity. In an embodiment, an
interior surface of the sidewall is angled from a bottom wall
toward one or more of the openings. In an alternate embodiment, an
interior surface of the sidewall is rounded from a bottom wall
toward one or more of the openings. An interior surface of the
sidewall may have an oval shape such that the long axis of the oval
interior sidewall is in alignment with one or more of the
openings.
[0014] The driver may be positioned below the fiber producing
device or above the fiber producing device, when the fiber
producing device is coupled to the driver. The driver may be
capable of rotating the fiber producing device at speeds of greater
than about 1000 RPM
[0015] In one embodiment, a heating device is thermally coupled to
the fiber producing device. In an embodiment, a fluid level sensor
is coupled to the fiber producing device, the fluid level sensor
being positioned to detect a level of fluid inside the fiber
producing device.
[0016] The fiber producing device may be enclosed in a chamber,
wherein the environment inside the chamber is controllable. A fiber
producing system may include a collection system surrounding at
least a portion of the fiber producing device, wherein fibers
produced during use are at least partially collected on the
collection system. The collection system, in one embodiment,
includes one or more collection elements coupled to a collection
substrate, wherein the one or more collection elements at least
partially surround the fiber producing device. In one embodiment,
the collection elements comprise an arcuate or straight projection
extending from the collection substrate surface.
[0017] In another embodiment a fiber producing system includes a
fiber producing device and a driver capable of rotating the fiber
producing device. The fiber producing device, in one embodiment,
includes a body having one or more openings and a coupling member,
wherein the body is configured to receive material to be produced
into a fiber; and one or more needle ports coupled to one or more
of the openings, wherein one or more needles are removably
couplable to the needle ports during use. The body of the fiber
producing device is couplable to the driver through the coupling
member. During use rotation of the fiber producing device coupled
to the driver causes material in the body to be ejected through one
or more needles coupled to one or more needle ports to produce
microfibers and/or nanofibers. In one embodiment, needles coupled
to the one or more needle ports have an angled and/or rounded
outlet.
[0018] In another embodiment a fiber producing system includes a
fiber producing device and a driver capable of rotating the fiber
producing device. The fiber producing device, in one embodiment,
includes a body comprising two or more chambers and a coupling
member, wherein a first chamber comprises one or more openings and
is configured to receive material to be produced into a fiber; and
wherein a second chamber comprises one or more openings and is
configured to receive material to be produced into a fiber. The
body of the fiber producing device is couplable to the driver
through the coupling member. During use, rotation of the fiber
producing device coupled to the driver causes material in at least
the first chamber and the second chamber to be ejected through the
one or more openings to produce microfibers and/or nanofibers.
[0019] In another embodiment a fiber producing system includes a
fiber producing device and a driver capable of rotating the fiber
producing device. The fiber producing device, in one embodiment,
includes a body comprising one or more openings and a coupling
member, wherein the body is configured to receive material to be
produced into a fiber. The body of the fiber producing device is
couplable to the driver through the coupling member. The fiber
producing system further includes a collection system that collects
fibers produced by the fiber producing device during use, the
collection system comprising one or more collecting elements
coupled to a collection element substrate, wherein one or more
collection elements comprise an arcuate projection extending from
the collection element substrate. During use, rotation of the body
coupled to the driver causes material in the body to be ejected
through one or more openings to produce microfibers and/or
nanofibers that are at least partially collected on the collecting
elements.
[0020] In an embodiment, a collection system of a fiber producing
system includes one or more collecting elements coupled to a
collection element substrate, wherein the collection elements are
positioned surrounding at least a portion of the fiber producing
device, and wherein the position of the collection elements with
respect to the fiber producing device is adjustable by moving the
collection elements along a portion of the collection element
substrate.
[0021] In another embodiment, a collection system of a fiber
producing system includes one or more collecting elements coupled
to a collection element substrate and a collection container,
wherein the collection container at least partially surrounds the
fiber producing device and wherein the collection elements are
removably positionable in the collection container.
[0022] In another embodiment, a collection system of a fiber
producing device is configured to collect fibers produced by the
fiber producing device. During use rotation of the fiber producing
device causes material in the body to be ejected through one or
more openings to produce microfibers and/or nanofibers. The
collection system produces a vacuum or activated a gas flow device
that causes a flow of produced fibers to the collection system.
[0023] In another embodiment a fiber producing system includes a
fiber producing device and a driver capable of rotating the fiber
producing device. The fiber producing device, in one embodiment,
includes a body comprising one or more openings and a coupling
member, wherein the body is configured to receive material to be
produced into a fiber. The body of the fiber producing device is
couplable to the driver through the coupling member. The fiber
producing system further includes a deposition system that collects
fibers produced by the fiber producing device during use and
directs the collected fibers toward a substrate disposed in the
deposition system during use. During use, rotation of the body
coupled to the driver causes material in the body to be ejected
through one or more openings to produce microfibers and/or
nanofibers that are at least partially transferred to the
deposition system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Advantages of the present invention will become apparent to
those skilled in the art with the benefit of the following detailed
description of embodiments and upon reference to the accompanying
drawings in which:
[0025] FIG. 1A depicts a perspective view of an embodiment of a
fiber producing device that includes peripheral openings;
[0026] FIG. 1B depicts a cross-sectional side view of an embodiment
of a fiber producing device that includes peripheral openings;
[0027] FIG. 2 depicts one or more nozzles coupled to one or more
openings of a fiber producing device;
[0028] FIG. 3 shows a cross-sectional view of the fiber producing
device of FIG. 2;
[0029] FIG. 4 shows a removably coupleable nozzle, needle port and
needle that have been removed from a fiber producing device;
[0030] FIG. 5 depicts a cross section view of an embodiment of a
nozzle that is couplable to a fiber producing device;
[0031] FIG. 6 depicts a cross-sectional top view of a fiber
producing device;
[0032] FIG. 7A depicts an alternate embodiment of a fiber producing
device;
[0033] FIG. 7B depicts cross-section view of an alternate
embodiment of a fiber producing device;
[0034] FIG. 8 depicts an embodiment of a removably couplable outlet
conduit;
[0035] FIGS. 9A and 9B depict cross-sectional views of embodiments
of a coupling portion of an opening in a body of a fiber producing
device;
[0036] FIGS. 10A and 10B depict cross-section end views of
embodiments of nozzles having a non-cylindrical profile;
[0037] FIGS. 11A-11F depict various outlet configurations for
nozzle tips and needle ends;
[0038] FIGS. 12A and 12B depict embodiments locking systems for a
needle;
[0039] FIGS. 13A-13C depict embodiments of locking systems for a
nozzle;
[0040] FIGS. 14A-14C depict alternate embodiments of locking
systems for needles;
[0041] FIGS. 15A and 15 B depict an alternate embodiment of a fiber
producing device;
[0042] FIG. 16 depicts an alternate embodiment of a fiber producing
device;
[0043] FIGS. 17A-17D depict examples of multiple level fiber
producing device;
[0044] FIG. 18 depicts a multiple level fiber producing system
having a material feed inlet;
[0045] FIG. 19 depicts a fiber producing device having a circular
support member;
[0046] FIGS. 20A and 20B depict a top view of a fiber producing
system that includes a fiber producing device and a collection
wall;
[0047] FIG. 21A depicts an embodiment of a collection system having
projecting collection elements;
[0048] FIG. 21B depicts an embodiment of a collection system having
arcuate collection elements;
[0049] FIGS. 22A and 22B depict an alternate embodiment of a
collection system;
[0050] FIGS. 23A-23C depict embodiments of a collection system
having removable collection substrates;
[0051] FIG. 24 depicts an embodiment of a diversion device coupled
to a collection system;
[0052] FIG. 25 depicts a fiber producing system disposed in a
housing;
[0053] FIG. 26 depicts a fiber producing system having a gas flow
collection system;
[0054] FIG. 27 depicts a fiber producing system having a vacuum
collection system;
[0055] FIG. 28 depicts a fiber producing system with a driver
mounted above the fiber producing device;
[0056] FIG. 29 depicts an embodiment of a portion of fiber
producing system configured for deposition of fibers on a
substrate;
[0057] FIG. 30 depicts an embodiment of a fiber producing system
configured for continuous deposition of fibers on a substrate;
[0058] FIG. 31 depicts an embodiment of a purge system coupled to a
fiber producing device;
[0059] FIG. 32 depicts a coaxial outlet element;
[0060] FIG. 33 depicts an inverted fiber producing system having a
continuous liquid mixture feed;
[0061] FIG. 34 depicts an inverted fiber producing device having a
continuous melt feed;
[0062] FIG. 35 depicts a substrate deposition system;
[0063] FIG. 36 depicts a fiber deposition system;
[0064] FIG. 37 depicts a deposition system that includes multiple
fiber producing devices;
[0065] FIGS. 38A-D depict an embodiment of a fiber producing
device;
[0066] FIG. 39 depicts an embodiment of a heating device;
[0067] FIG. 40 depicts an alternate embodiment of a fiber producing
device;
[0068] FIG. 41A-B depict a star shaped fiber producing device;
and
[0069] FIG. 42 depicts a gear shaped fiber producing device.
[0070] While the invention may be susceptible to various
modifications and alternative forms, specific embodiments thereof
are shown by way of example in the drawings and will herein be
described in detail. The drawings may not be to scale. It should be
understood, however, that the drawings and detailed description
thereto are not intended to limit the invention to the particular
form disclosed, but to the contrary, the intention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the present invention as defined by the
appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0071] It is to be understood the present invention is not limited
to particular devices or methods, which may, of course, vary. It is
also to be understood that the terminology used herein is for the
purpose of describing particular embodiments only, and is not
intended to be limiting. As used in this specification and the
appended claims, the singular forms "a", "an", and "the" include
singular and plural referents unless the content clearly dictates
otherwise. Furthermore, the word "may" is used throughout this
application in a permissive sense (i.e., having the potential to,
being able to), not in a mandatory sense (i.e., must). The term
"include," and derivations thereof, mean "including, but not
limited to." The term "coupled" means directly or indirectly
connected.
[0072] The terms "comprise" (and any form of comprise, such as
"comprises" and "comprising"), "have" (and any form of have, such
as "has" and "having"), "include" (and any form of include, such as
"includes" and "including") and "contain" (and any form of contain,
such as "contains" and "containing") are open-ended linking verbs.
As a method or apparatus that "comprises," "has," "includes" or
"contains" one or more steps or elements possesses those one or
more steps or elements, but is not limited to possessing only those
one or more steps or elements. Likewise, an element of an apparatus
that "comprises," "has," "includes" or "contains" one or more
features possesses those one or more features, but is not limited
to possessing only those one or more features.
[0073] Described herein are apparatuses and methods of creating
fibers, such as microfibers and nanofibers. The methods discussed
herein employ centrifugal forces to transform material into fibers.
Apparatuses that may be used to create fibers are also described.
Some details regarding creating fibers using centrifugal forces may
be found in the following U.S. Published Patent Applications:
2009/0280325 entitled "Methods and Apparatuses for Making Superfine
Fibers" to Lozano et al.; 2009/0269429 entitled "Superfine Fiber
Creating Spinneret and Uses Thereof" to Lozano et al.; 2009/0232920
entitled "Superfine Fiber Creating Spinneret and Uses Thereof" to
Lozano et al.; and 2009/0280207 entitled "Superfine Fiber Creating
Spinneret and Uses Thereof" to Lozano et al., all of which are
incorporated herein by reference.
[0074] One embodiment of a fiber producing device is shown in FIG.
1A. Fiber producing device 100 includes a top 110 that is coupled
to body 120. Body 120 acts as a reservoir which holds material to
be spun into fibers. Top 110 has an opening 112 to allow
introduction of material to be spun. For this type of fiber
producing device, typical amounts of material range from 50-100 mL,
but amounts less than this may be used as well as amounts greater
than this, as the size of the reservoir and the fiber producing
device may each vary. Body 120 includes one or more openings 122. A
coupling member 160 is coupled to the body. Coupling member 160 may
be used to couple fiber producing device 100 to a driver that is
capable of rotating the fiber producing device. Coupling member 160
may be an elongated member extending from the body which may be
coupled to a portion of the driver (e.g., a chuck or a universal
threaded joint of the driver). Alternatively, coupling member may
be a receiver which will accept an elongated member from a driver
(e.g., the coupling member may be a chuck or a universal threaded
joint). Suitable drivers include commercially available variable
electric motors, such as a brushless DC motor.
[0075] During use, rotation of the fiber producing device causes
material to be ejected through one or more openings 122 to produce
fibers. In some embodiments, openings 122 may have a size and/or
shape that causes the creation of microfibers and/or nanofibers as
the material is ejected through the openings.
[0076] FIG. 1B depicts a cross-sectional side view of an embodiment
of fiber producing device 100. Body 120 of fiber producing device
100 may further include a tip 124 coupled to one or more openings
122. Body 120 also defines an internal cavity 145 from which
material flows toward openings 122 and, optionally, through tip
124. In some embodiments, tip 124 has an internal diameter that is
less than the diameter of the opening. Tip 124 is coupled to an
opening 122 formed in a wall of body 120 such that the tip is
substantially aligned with opening. Thus, material disposed in
internal cavity 145 passes through opening 122 and through tip 124
when exiting fiber producing device 100. The internal diameter
and/or shape of tip 124 is selected such that microfibers and/or
nanofibers are produced when the material is ejected from body 120
of a spinning fiber producing device through the tip. Tip 124 may
be removably coupled to body 120. Alternatively, tip 124 and body
120 are formed from a single, unitary material such that the tip is
not removable from the body, but instead is an integral part of the
body.
[0077] In an embodiment depicted in FIG. 2, one or more nozzles 130
may be coupled to one or more openings 122 of fiber producing
device 100. As used herein a "nozzle" is a mechanical device
designed to control the direction or characteristics of a fluid
flow as it exits (or enters) an enclosed chamber or pipe via an
orifice. Nozzles may have an internal cavity 138 running through
the longitudinal length of the nozzle, as depicted in FIG. 3.
Internal cavity 138 may be substantially aligned with opening 122
when nozzle 130 is coupled to an opening. Spinning of fiber
producing device 100 causes material to pass thorough one or more
of openings 122 and into one or more nozzles 130. The material is
then ejected from one or more nozzles 130 through nozzle orifice
136 to produce fibers. Nozzle 130 may include a nozzle tip 134
having an internal diameter smaller than an internal diameter of
nozzle internal cavity 138. In some embodiments, internal cavity
138 of nozzle 130 and/or nozzle orifice 136 may have a size and/or
shape that causes the creation of microfibers and/or nanofibers by
ejecting of the material through the nozzle.
[0078] It should be understood that while opposing openings are
depicted, the openings may be placed in any position on the body of
a fiber producing device. The position of the openings may be
varied to create different kinds of fibers. In some embodiments,
openings may be placed in different planes of the fiber producing
device. In other embodiments, openings may be clustered in certain
locations. Such alternate positioning of the openings may increase
the fiber dispersion patterns and/or increase the fiber production
rates. In some embodiments, the openings, regardless of the
position, may accept an outlet element (e.g., a nozzle or
needle).
[0079] FIG. 3 shows a cross-sectional view of fiber producing
device of FIG. 2. Body 120 includes one or more sidewalls 121 and a
bottom 123 which together define an internal cavity 125. In one
embodiment, body 120 is substantially circular or oval and includes
a singular continuous sidewall 121, for example, sidewall and
bottom are a single, unitary component of the fiber producing
device. Openings 122 are formed in sidewall 121 of body 120,
extending through the sidewall such that the opening allows
transfer of material from internal cavity 125 through the sidewall.
In an embodiment, sidewall 121 is angled from bottom 123 toward one
or more openings 122. Alternatively, sidewall 121 may be rounded
from bottom 123 toward one or more openings 122. Having an angled
or rounded sidewall extending toward one or more openings
facilitates flow of material in the body toward the openings when
the fiber producing device is being rotated. As the fiber producing
device is rotated the material rides up the angled or rounded walls
toward the openings. This minimizes the occurrence of regions where
material is inhibited from traveling toward the openings.
[0080] In an embodiment, nozzle(s) 130 may be removably coupled to
body 120. For example, nozzle 130 may include a nozzle coupling
portion 132 which is couplable to a corresponding coupling portion
127 of one or more of openings 122. FIG. 4 shows a removably
coupleable nozzle 130 that has been removed from fiber producing
device 100. In this embodiment, nozzle 130 includes a threaded
coupling portion 132, which has threading that matches threading
127 formed in opening 122. Nozzle 130 may be coupled to body 120 by
fastening threaded coupling portion 132 onto threading 127 of
opening 122. Removably coupling a nozzle to a fiber producing
device allows removal of the nozzles allowing the ability to
customize the production of fibers by allowing the outlet
parameters to be changed by changing the nozzle. Additionally clean
up of the fiber producing device is improved by allowing the nozzle
to be removed and separately cleaned.
[0081] FIG. 5 depicts a cross section view of an embodiment of a
nozzle 130 that is couplable to a body of a fiber producing device.
Nozzle 130 includes a nozzle body 131 having a proximal end 133 and
a distal end 135. Proximal end 133 includes a coupling portion 132
that allows nozzle 130 to be coupled to the body of a fiber
producing device. Coupling portion 132 may include a threaded
portion which has threading that matches threading formed in an
opening of a fiber producing device.
[0082] Nozzle 130 further includes a nozzle tip 134 coupled to
distal end 135 of the nozzle. Nozzle body 131 defines an internal
cavity 138 through which material flows from the body of a fiber
producing device toward nozzle orifice 136. In some embodiments,
nozzle tip 134 has an internal diameter that is less than the
diameter of internal cavity 138. Nozzle tip 134 is coupled to an
opening 139 formed in a wall of nozzle body 131. Nozzle tip 134 is
aligned with opening 139 such that material disposed in internal
cavity 138 passes through opening 139 into the nozzle tip. The
internal diameter and/or shape of nozzle tip 134 is selected such
that microfibers and/or nanofibers are produced when the material
is ejected form the body of a spinning fiber producing device
through the nozzle.
[0083] Nozzle tip 134 may be removably coupled to nozzle body 131.
Alternatively, nozzle tip 134 and nozzle body 131 are formed from a
single, unitary material such that the nozzle tip is not removable
from the nozzle body, but instead is an integral part of the nozzle
body. Nozzle tip may be angled with respect to nozzle body. In some
embodiments, nozzle 130 has a length of at least about 10 mm. In
some embodiments, nozzle 130 has a length of between about 5 mm to
about 15 mm. An internal diameter of nozzle 130 may range from
about 1.0 mm to about 1 mm, depending on the size of fibers to be
produced and the viscosity of the material being used to produce
the fibers.
[0084] To facilitate transfer of material through nozzle 130, a
portion of nozzle body 131 may be angled or rounded toward opening
139. For example, distal portion 135 of nozzle body 131 may be
angled from a flat portion of the nozzle body toward opening 139.
Alternatively, distal portion 135 of nozzle body 131 may be
rounded, as depicted in FIG. 5, from a flat portion of the nozzle
body toward opening 139.
[0085] In another embodiment, a needle port 140 may be coupled to
an opening 122 of body 120. FIG. 4 depicts an embodiment of a
removably couplable needle port that has been removed from fiber
producing device 100. Needle port 140 may include a coupling
portion 142 and a needle receiving portion 144. Needle receiving
portion 144 may be used to removably couple a needle to needle port
140. In an embodiment, needle port 140 is a luer-lock connector.
Coupling portion 142 of needle port 140 is couplable to a
corresponding coupling portion 127 of one or more of openings 122.
For example, needle port 140 may include a threaded coupling
portion 142, which has threading that matches threading 127 formed
in opening 122. Needle port 140 may be coupled to body 120 by
fastening the threaded coupling portion 142 of the needle port onto
threading 127 of opening 122. Removably coupling a needle port to a
fiber producing device allows easy removal of the needle port for
clean up. Needle ports offer an additional advantage of allowing
customization of the fiber producing device by allowing needles to
be removably coupled to the fiber producing device.
[0086] In another embodiment, a needle 150 may be coupled to an
opening 122 of body 120. FIG. 4 depicts an embodiment of a
removably couplable needle that has been removed from fiber
producing device 100. Needle 150 may include a coupling portion
152. Coupling portion 152 of needle port 150 is couplable to a
corresponding coupling portion 127 of one or more of openings 122.
For example, needle 150 may include a threaded coupling portion
152, which has threading that matches threading 127 formed in
opening 122. Needle 150 may be coupled to body 120 by fastening the
threaded coupling portion 152 of the needle onto threading 127 of
opening 122. Removably coupling a needle to a fiber producing
device allows easy removal of the needle for clean up. Having a
coupling formed on a needle ports offer an additional advantage of
allowing customization of the fiber producing device by allowing
needles to be removably coupled to the fiber producing device.
[0087] FIG. 6 depicts a cross-sectional top view of fiber producing
device 100. To further facilitate transfer of material, fiber
producing device 100 may have a substantially oval internal cavity
125. For example, sidewall 121 may define an internal cavity 125
having a substantially oval cross-sectional shape. The oval
internal cavity has a long axis 610 and a short axis 620. Long axis
610 of internal cavity 125 may be aligned with one or more openings
122. While internal cavity 125 has a substantially oval shape, the
external shape of body may be substantially circular. This may be
accomplished by varying the sidewall width to create an oval
internal cavity while maintaining a circular external surface 630
of the body. As shown in FIG. 6, sidewall thickness "x" along the
short axis 620 may be larger than the sidewall thickness "y" along
long axis 610. This creates an oval shape for internal cavity 125
while maintaining a circular external surface 630. Having an oval
internal cavity helps to drive the material along the long axis of
the oval when the fiber producing device is spinning. When the long
axis is aligned with one or more openings, the material is thus
directed to the openings, helping to minimize waste and ensure a
continuous flow of material through the openings.
[0088] An alternate embodiment of a fiber producing device is shown
in FIG. 7A. Fiber producing device 200 includes a top 210 that is
coupled to body 220. Body 220 acts as a reservoir which holds
material to be spun into fibers. Top 210 has an opening 212 to
allow introduction of material to be spun while the top is fastened
to body 220. Alternatively, top 210 may be removed from body 220
and the material added to the body prior to fastening the top to
the body. Body 220 includes one or more openings 222 and a coupling
member 260 coupled to the body. Coupling member 260 may be used to
couple fiber producing device 200 to a driver that is capable of
rotating the fiber producing device. Coupling member 260 may be an
elongated member extending from the body which may be coupled to a
portion of the driver (e.g., a chuck or a universal threaded joint
of the driver). Alternatively, coupling member may be a receiver
which will accept an elongated member from a driver (e.g., the
coupling member may be a chuck or a universal threaded joint).
[0089] One or more needle ports 240 may be coupled to one or more
openings 222 via one or more outlet conduits 270. Outlet conduits
270 may have an annular passageway 272 extending through the
longitudinal length of the outlet conduit, as depicted in cross
section view FIG. 7B. Outlet conduit 270 may have a length of at
least about 10 mm, at least about 20 mm, at least about 30 mm, at
least about 40 mm, at least about 50 mm, at least about 60 mm
inches, or at least about 70 mm. Outlet conduit 270 may have a
length of between about 10 mm to about 250 mm, at least about 20 mm
to about 200 mm, or at least about 30 mm to about 150 mm.
[0090] When material is ejected from an opening during spinning of
a fiber producing body, the material tends to expand as it leaves
an opening. It has been found that by "setting" the diameter of the
material prior to the material exiting the fiber producing device,
expansion of the material as it leaves the fiber producing device
may be minimized. To "set" the diameter of the material annular
passageway 272 may have a substantially constant diameter. In some
embodiments, the annular passage has a constant diameter of between
about 4 mm and about 30 mm over a length of about 10 mm to about
250 mm. Holding the material at a constant diameter over a
predetermined length, sets the diameter of the material, reducing
the expansion of the material as it exits the outlet conduit and
nozzle. Reduction of swelling helps to improve the consistency of
the produced fibers with regard to size and length. The length
and/or diameter of annular passage 272 may be selected based, at
least in part, on the type of material being used. Generally, as
the viscosity of the material increases, a longer conduit may be
used to properly set the diameter of the material before the
material exits the fiber producing device.
[0091] In an embodiment, outlet conduits 270 may be removably
coupled to body 220. FIG. 8 depicts an embodiment of a removably
couplable outlet conduit 270. Outlet conduit 270 may include a
first coupling portion 274 which is couplable to a complementary
coupling portion 227 of a body 220 and a second coupling portion
276 couplable to an outlet element 280. An outlet element, as used
herein includes, but is not limited to, a nozzle, a needle port, a
needle or a combination of an outlet conduit coupled to a nozzle,
needle port or needle. Outlet element 280 includes a complementary
coupling portion 282, which is couplable to second coupling portion
276 of outlet conduit 270. An outlet element 280 may be coupled to
outlet conduit 270 by mating second coupling portion 276 of the
outlet conduit onto coupling portion 282 of the outlet element.
Removably coupling an outlet conduit to a body allows easy removal
of outlet conduits. Having removably coupled outlet conduits
improves the ability to customize the production of fibers by
allowing the outlet parameters to be changed by changing the outlet
conduit length and diameter as well and the outlet element that is
coupled to the outlet conduit. Additionally clean up of the fiber
producing device is improved by allowing the outlet conduit to be
removed and separately cleaned. Outlet elements such as nozzle 130,
needle port 140 and needle 150, as depicted in FIG. 4, may be
coupled to second coupling portion 276 of outlet conduit 270.
[0092] FIG. 9A depicts a cross-sectional view of a coupling portion
310 of an opening in a body 300 of a fiber producing device.
Coupling portion 310 depicted in FIG. 9A may be used to couple a
nozzle, a needle, a needle port, or an outlet conduit to body 300
of a fiber producing device. Coupling portion 310 includes, in one
embodiment, threading 312 that couples with threading 322 of a
removably couplable outlet element 320 (e.g., a nozzle, a needle, a
needle port, or an outlet conduit). In one embodiment, threading
312 is formed on an interior wall of opening 302. Outlet element
320 includes threading 322 that is complementary to the threading
on coupling portion 310 of opening 302 to allow coupling of the
outlet element to the body. A seal 350 (e.g., an o-ring) may be
positioned between outlet element 320 and body 300 to form a seal
between the body and the outlet element.
[0093] An alternate embodiment of a coupling portion 310 of a body
300 of a fiber producing device is depicted in the cross-section
drawing depicted in FIG. 9B. In an embodiment, coupling portion 310
includes a coupling member 340 formed proximate to an opening 302
formed in a sidewall of body 300. Coupling member 340 may protrude
from opening 302. Coupling member 340 includes, in one embodiment,
threading 314 formed on an external surface of the coupling member
that couples with threading 324 of a removably couplable outlet
element 320 (e.g., a nozzle, a needle, a needle port, or an outlet
conduit). A seal 350 (e.g., an o-ring) may be positioned between
outlet element 320 and body 300 to form a seal between the body and
the outlet element.
[0094] In an embodiment, one or more nozzles may be coupled to the
body of a fiber producing device. During use material in the fiber
producing device passes through the one or more nozzles and is
ejected from the one or more nozzles to produce microfibers and/or
nanofibers. In embodiments where the nozzles protrude from the body
of a fiber producing device, the nozzles may be cooled by air
striking the nozzle as the body is rotated. During a process in
which a heated material is used, the cooling of the nozzles may
cause the material passing through the nozzle to be cooled prior to
exiting the nozzle. This cooling may cause inconsistent fiber
production as the material properties (e.g., viscosity) change as
the material is cooled. To minimize the cooling effect of air on
the nozzles, the nozzles may be formed to have a non-cylindrical
profile. FIGS. 10A and 10B depict cross-section end views of
embodiments of nozzles having a non-cylindrical profile. In the
embodiment shown in FIG. 10A, a nozzle 410 has an outer surface
having tapered edge 412. Nozzle 410 is positioned on a body of a
fiber producing device such that the nozzle is rotated in a
direction leading with tapered edge 412 (in FIG. 10A this would be
in a direction right to left or clockwise). Air 414 flows around
the tapered edge creating a region of negative pressure 416 around
orifice 418 of nozzle 410. Region of negative pressure 416 is
believed to slow down the heat transfer from the nozzle to the air.
Having a tapered leading edge may also reduce the disruption of air
flow on fiber forming as the material exits the nozzle.
[0095] FIG. 10B depicts an alternate embodiment of a
non-cylindrical nozzle. In the embodiment shown in FIG. 10B, a
nozzle 420 has an outer surface having tapered leading edge 422 and
a tapered trailing edge 423. Nozzle 420 is positioned on a body of
a fiber producing device such that the nozzle is rotated in a
direction leading with leading edge 422 (in FIG. 10B this would be
in a direction right to left or clockwise). Air 424 flows around
the tapered edge creating a region of negative pressure 426 around
orifice 428 of nozzle 410. Region of negative pressure 426 is
believed to slow down the heat transfer from the nozzle to the air
and reduce the disruption of gas flow on fiber forming as the
material exits the nozzle.
[0096] The end of a nozzle, a nozzle tip, and the end of a needle
coupled to a fiber producing device may be angled or rounded to
alter the fiber size and configuration. Examples of various outlets
configurations that may be used for both nozzle tips and needle
ends are shown in FIGS. 11A-11F. In each of the figures the
downward pointing arrow indicates the direction of gas flow across
the end of the nozzle tip/needle end. In FIG. 11A, a nozzle tip or
needle end has a flat end. A variation of the nozzle tip or needle
end which may be used to alter the properties of the fiber produced
include an angled nozzle tip or needle end, as depicted in FIG.
11B, or various rounded nozzle tip or needle end configurations, as
depicted in FIGS. 11C-11E. By changing the angle and configuration
of a nozzle tip or needle end the material may be drawn into
different fibers. In configuration 11F, a slight indentation is
formed in nozzle tip or needle end to produce a region of reduced
pressure at the end of the needle, facilitating production of
fibers.
[0097] It has been further discovered that alterations in the angle
of the nozzle or needle with respect to the body may also influence
the properties of the produced fibers. For example, as depicted in
the figures, nozzles and/or needles are typically positioned
substantially perpendicular to the body. In some embodiments,
nozzles or needles may be placed at an angle deviating from
perpendicular by any amount. In some embodiments, the nozzle or
needle may be placed on the body at an angle deviating from between
about 1 to about 15 from perpendicular.
[0098] Production of desired fibers may therefore be controlled by
the type of nozzle or needle used, the orientation of the nozzle or
needle with respect to the direction of rotation, the nozzle tip or
needle end configuration, and the angle of the nozzle or needle
with respect to the body. In order to facilitate proper placement
of the nozzle or needle on the body, different locking systems may
be used. FIG. 12A shows a locking system that may be used for a
needle. Needle 500 includes a protrusion 510 at the coupling end of
needle 500. An opening 520, that the needle is to be coupled with,
has a complementary shape to the protrusion at the end of needle
500. During use, needle 500 may only be inserted into opening 520
in the specific orientation that allows protrusion 510 to be
inserted into the opening. A locking screw (not shown) may be used
to lock needle 500 in place once the needle is properly inserted in
opening 520. In this manner, the needle may be placed in the proper
orientation without the user having to check for proper positioning
of the needle. For example, if the tip of the needle has a specific
configuration, (e.g., as depicted in FIGS. 11B-11F), the use of a
locking system may ensure that the needle tip is in the proper
orientation with respect to the rotation of the body.
[0099] An alternate embodiment of a needle locking system is shown
in FIG. 12B. Locking system 540 may include a plurality of angled
protrusions 545 arranged in a circle and extending from a locking
member. Needle coupling end 530 may also include a similar pattern
of angled protrusions that will complement the protrusions on
locking system 540. During use, needle coupling end may be mated
with the protrusions of locking system 540 in a predetermined
number of discrete positions. When placed in the desired position
the needle may be locked in place using the locking system. In an
embodiment, a locking screw (not shown) may be used to lock the
needle in place once the needle is properly positioned. In
alternate embodiments, a clamp or clamping mechanism may be used to
secure the needle coupling portion to the locking system. In this
manner, the needle may be ensured to be placed in a selected
discrete the proper orientation. Locking system 540 further offers
the additional feature of allowing the needle to be placed in
discrete, predetermined positions with respect to the body
[0100] Nozzles may also be coupled to a body through a locking
system that positions the nozzle in a predetermined orientation. An
embodiment of a locking system for a nozzle is depicted in FIGS.
13A and 13B. In this embodiment, a nozzle 600 may include a
coupling portion 610. Nozzle 600 may be couplable to an opening 620
by sliding the nozzle coupling portion 610 into opening 620, in
contrast to previous embodiments in which the nozzle included a
threaded coupling portion. Coupling portion 610 of nozzle 600 has a
flat portion 612 which is matched with a corresponding flat portion
622 of an opening. The requirement to match the flat portion of the
nozzle coupling end with a flat portion of the opening ensures that
the nozzle is placed in the proper orientation. A seal 630 (e.g.,
an o-ring) may be positioned between the nozzle and the body to
form a seal. To secure nozzle 600 in opening 620, a set screw 635
may be used. In an embodiment, depicted in FIG. 13B, set screw 635
may extend through body 640 of a fiber producing device and contact
the flat portion of the coupling portion 610 of nozzle 600 to
secure the nozzle in the opening. Alternatively, the set screw may
engage the nozzle coupling end at an angle extending through the
sidewall of the body.
[0101] An alternate embodiment of a locking system for a nozzle is
depicted in FIG. 13C. In this embodiment, a nozzle 600 may have a
coupling end that includes one or more protrusions 652. Locking
system includes one or more recess 662 which can be matched with
one or more protrusions 652 of nozzle 600 to lock the nozzle in a
predetermined position. The requirement to match protrusions 652 of
nozzle 600 with recesses 662 ensures that the nozzle is placed in
the proper orientation. A seal 650 (e.g., an o-ring) may be
positioned between nozzle 600 and body to form a seal between the
body and the nozzle. To secure the nozzle in the opening, a set
screw 635 may be used. In an embodiment, set screw 635 may extend
through the body, contacting the coupling end of nozzle to secure
the nozzle in the opening.
[0102] An embodiment of a locking system for a needle is depicted
in FIG. 14A. A needle is couplable to an opening 710 of the body of
a fiber producing device. Needle 700 includes a coupling portion
702 that includes a base 704 and a seal 708 positioned around at
least a portion of the base. An indentation 707 may be formed in
base 704. To secure needle 700 in the opening, a set screw 720 may
be used. Set screw 720 may extend through the body of a fiber
producing device and contact indentation 707 formed in base 704 of
needle 700 to secure the needle in opening 710. Alternatively, the
set screw may engage the indentation of the needle at an angle
extending through the sidewall of the body. The formation of an
indentation on the needle base helps secure the needle in the
opening and helps a user to align the needle in the proper
orientation. Seal 708 (e.g., an o-ring) helps to form a seal
between the base and the opening.
[0103] Another embodiment of a locking system for a needle is
depicted in FIG. 14B and FIG. 14C. In this embodiment, a needle 700
is couplable to an opening of the body of a fiber producing device.
Needle 700 includes a coupling portion 730 that includes base 732
and a locking tab 734 protruding from the base. An opening of the
body of a fiber producing device, or a needle port, may have a
locking system capable of securing needle 700. An example of a
locking system 740 is depicted in FIG. 14C. Locking system 740
includes an indentation 742 that receives locking tab 734 and a
portion of base 732. To secure the needle in an opening, needle 700
is oriented such that locking tab 734 is aligned with indentation
742 of locking system 740. Once locking tab 734 is inserted into
indentation 742, base 732 can be turned to secure locking tab 734
under a portion 744 of locking system 740. A set screw may be used
to secure the needle in the locking system. In some embodiments, a
set screw may not be needed. Base 732 may include one or more seals
736. Seals 736 may provide a secure fitting between a portion of
base 732 and the surface of the body or needle port. When in
contact with the surface of the body or a needle port, the seal
also provides an outward force against the base, causing a portion
of the base to be compressed against an inner surface of the
locking system. Additional seals help to form a more secure fitting
between the base and the opening.
[0104] An alternate embodiment of a fiber producing device is
depicted in FIGS. 15A and 15B. Fiber producing device 800 includes
a hub 810 and a body 820. Body 820 acts as a reservoir in which
material may be placed. Body 820 includes one or more openings 822
through which material may exit. One or more needles 824, or other
outlet elements, may be coupled to openings 822. A hub 810 may be
used to secure body 820. In an embodiment, hub 810 is a spherical
hub that includes a cylindrical opening 812 to receive the body. A
coupling member 830 is coupled to hub 810. Coupling member 830 may
be used to couple hub 810 to a driver that is capable of rotating
the hub. Coupling member 830 may be an elongated member extending
from the body which may be coupled to a portion of the driver
(e.g., a chuck or a universal threaded joint of the driver).
Alternatively, coupling member 830 may be a receiver, as depicted
in FIG. 15A, which will accept an elongated member from a driver
(e.g., the coupling member may be a chuck or a universal threaded
joint).
[0105] Body 820 is coupled to hub 810 by inserting the body into
cylindrical cavity 812. A locking mechanism 840 is disposed in
cylindrical cavity 812 of hub 810. In one embodiment, locking
mechanism 840 includes a spring-loaded ball 842 which rests in a
cavity 844 formed in the body and coupled to cylindrical cavity
812. Body 820 includes an indentation 826 that has a shape
complementary to ball 842. To lock body 820 inside hub 810, body
820 is slid into cylindrical cavity 812. When body 820 reaches
locking mechanism 840, the surface of the body contacts ball 842
and forces the ball into cavity 844, allowing the body to continue
into the cylindrical cavity. Body 820 is pushed through cylindrical
cavity until indentation 826 of the body aligns with ball 842. At
this point, the spring forces ball 842 into the indentation,
inhibiting further movement of the body along cylindrical cavity
844. To ensure that body 820 remains locked in hub 810, a set screw
850 may contact the body. The pressure of set screw 850 and the
resistance force of ball 842 helps to inhibit further movement of
body 820 within cylindrical cavity 812. In some embodiments, a
second indentation 828 is formed in the body to receive the set
screw 850. In some embodiments, body 820 has been preloaded with
the material to be spun. While cavity 812 and body 820 are depicted
as cylindrical, it should be understood that other shapes may be
used.
[0106] During use, rotation of hub 810 causes material to be
ejected through one or more of openings 822 to produce fibers.
During rotation ball 842 and, optionally, set screw 850 secure body
820 within hub 810. When fiber formation is finished, set screw 850
may be withdrawn such that the set screw no longer contacts body
820. Removal of the set screw 850 may allow a force to be applied
to body 820 sufficient to overcome the resistance created between
ball 842 and body, allowing the body be slid out of hub 810. The
removed body may be replaced by a second body and fiber production
continued while the first body is being cleaned and replenished
with material.
[0107] FIG. 16 depicts an alternate embodiment of a fiber producing
device. Fiber producing device 900 includes a spherical body 910
which defines an internal cavity. Openings are formed in a sidewall
of body 910, extending through the sidewall such that the opening
allows transfer of material from the internal cavity through the
sidewall. The openings, in one embodiment, communicate with a
coupling member 930, which is couplable to an outlet element. In an
embodiment, an outlet element 920 such as a nozzle, needle port,
needle, or outlet conduit, may be removably coupled to body 910.
Coupling member 960 may be used to couple body 910 to a driver that
is capable of rotating the body. Coupling member 960 may be an
elongated member extending from body 910 to a portion of a driver
(e.g., a chuck or a universal threaded joint of the driver).
Alternatively, coupling member 960 may be a receiver, as depicted
in FIG. 16, which will accept an elongated member from a driver
(e.g., the coupling member may be a chuck or a universal threaded
joint). Spherical body also includes an inlet port 940 that may be
used to introduce material into the internal cavity.
[0108] In some embodiments it is desirable to have a rotationally
balanced system. Thus nozzles, needles, or needle ports are
typically positioned as opposing pairs to maintain a rotationally
balanced hub. Alternatively, if an odd number of nozzles, needles
or needle ports are used, these devices may be positioned in a
balanced orientation (e.g., three devices can be positioned at a
120 angle from each other). In some embodiments, however, it may
not be desirable to have two or more devices that are producing
fibers. It may be desirable to have only a single fiber producing
outlet from the body. While this may be achieved by simply coupling
a single outlet device to the hub, such a situation may create a
rotationally unbalanced system that creates rotational stress on
the body and the driver. To offset the weight of an unpaired outlet
element, a counter weight may be coupled to an opposing (or a
positionally balanced) outlet. For example, as depicted in FIG. 16,
a counterweight 950 may be coupled to an opening, while an outlet
element 920 is coupled to the opposing opening. Thus, material only
exits the outlet element 920, while counterweight 950 inhibits
material from being ejected through the opposing opening.
Counterweight 950 helps to balance the system and reduce the
rotational stress on the body and driver.
[0109] In some embodiments, it may be desirable to spin two or more
different materials at the same time. For example, it may be
desirable to spin two different types of polymers, or a polymer and
a metal substantially simultaneously. This may be used to create
blended microfibers and/or nanofibers by simultaneously producing
different types of fibers from a single device. An example of a
multiple level fiber producing device is depicted in FIGS. 17A and
17B. Fiber producing device 1000 includes a body 1010 having two or
more chambers. For example, in the embodiment depicted in FIG. 17A,
a fiber producing device 1000 includes three chambers, 1012, 1014,
and 1016. Each of the chambers includes one or more openings (1022,
1024, and 1026, respectively) that allow material to be placed into
the chambers. Each chamber further includes one or more openings
(1011, 1013, and 1015, respectively) through which material
disposed in the chambers may be ejected. During use, rotation of
the fiber producing device causes material to be ejected through
one or more of openings 1011, 1013, and 1015 of each chamber that
includes material to produce fibers. In some embodiments, openings
1011, 1013, and 1015 may have a size and/or shape that causes the
creation of microfibers and/or nanofibers as material is ejecting
through the openings. In other embodiments, outlet elements may be
coupled to one or more of openings 1011, 1013, and 1015. If
different materials are placed in different chambers, two or more
different fibers may thus be simultaneously produced.
[0110] In one embodiment, the chambers may be removably coupled to
each other. For example, as depicted in FIGS. 17A and 17B, a second
chamber 1014, may be coupled to first chamber 1012 through a
coupling mechanism. In an embodiment, first chamber 1012 includes a
coupling section 1032 having threading on the interior portion of
the coupling section. Second chamber 1014 may have complementary
threading on an exterior surface of a coupling section 1034. To
assemble the multi chamber device, second chamber 1014 may be
threaded onto the first chamber 1012. In a like manner, third
chamber 1016 may be coupled to second chamber 1014. Furthermore,
first chamber may be coupled to body 1010 using a similar coupling
mechanism. While three chambers are depicted, it should be
understood that more or less than three chambers may be coupled
together. Each chamber material inlet (1022, 1024, and 1026) may be
positioned such that material may be selectively added to each
chamber (1012, 1014, and 1016, respectively), without adding
material to other chambers. A seal 1040 (e.g., an o-ring) may be
placed between coupling portions of the chambers to provide a
seal.
[0111] Multilevel fiber producing device 1000 includes a coupling
member 1050 which couples fiber producing device 1000 to a driver
1055 that is capable of rotating the fiber producing device.
Coupling member 1050 may be an elongated member extending from the
body which may be coupled to a portion of the driver (e.g., a chuck
or a universal threaded joint of the driver). Alternatively,
coupling member may be a receiver, as depicted in FIG. 17A, which
will accept an elongated member from a driver (e.g., the coupling
member may be a chuck or a universal threaded joint).
[0112] In some embodiments, it may be desirable to control the
spacing between the chambers. For example, as depicted in FIG. 17A,
the chambers are spaced apart from each other based on the size of
the coupling portions. However, the coupling portions may not
create a sufficient spacing to provide the desired separation of
the chambers. In some embodiments, a spacer 1060, may be used to
create additional separation between the chambers, as depicted in
FIG. 17B. Use of spacers may help reduce the number of chambers
needed to customize the fiber producing device. For example, rather
than creating chambers having different size coupling portions, a
variety of different spacers may be used to create different
spacings between the chambers without having to modify the
chambers.
[0113] Another example of a multiple level fiber producing device
is depicted in FIG. 17C. Fiber producing device 1000 includes a
body 1010 having two or more levels. For example, in the embodiment
depicted in FIG. 17C, a fiber producing device 1000 includes three
levels having one or more openings (1011, 1013, and 1015,
respectively) through which material disposed in the chambers may
be ejected. An interior cavity 1012 of body 1010 may have a curved
interior surface, curving from the bottom of the cavity toward
openings 1011 of the first level. In this manner, material disposed
in cavity 1012 is directed toward openings. Generally the diameter
of openings 1011, 1013, and 1015 are set such that material moves
up the interior surface of cavity 1012 until and reaches all of the
openings at once. The openings may be a horizontally and/or
vertically displaced from each other in a predetermined pattern.
For example, the openings may be positioned in an ordered manner to
form one or more levels of openings, as depicted in FIG. 17C.
[0114] During use, rotation of the fiber producing device causes
material to be ejected through one or more of openings 1011, 1013,
and 1015 of each level to produce fibers. In some embodiments,
openings 1011, 1013, and 1015 may have a size and/or shape that
causes the creation of microfibers and/or nanofibers as material is
ejecting through the openings. In other embodiments, outlet
elements may be coupled to one or more of openings 1011, 1013, and
1015. If different materials are placed in different chambers, two
or more different fibers may thus be simultaneously produced.
[0115] In one embodiment, the levels may be removably coupled to
each other. For example, as depicted in FIG. 17C, a second level
may be coupled to first level through a coupling mechanism. In an
embodiment, coupling section 1032 having threading on the interior
portion of the coupling section joins the first level to the second
level. Second level may have complementary threading on an exterior
surface of a coupling section 1034. To assemble the multi chamber
device, second level may be threaded onto the first level. In a
like manner, third level may be coupled to second level.
Furthermore, first level may be coupled to body 1010 using a
similar coupling mechanism. While three levels are depicted, it
should be understood that more or less than three levels may be
coupled together. A seal 1040 (e.g., an o-ring) may be placed
between coupling portions of the chambers to provide a seal.
[0116] Multilevel fiber producing device 1000 includes a coupling
member 1050 which couples fiber producing device 1000 to a driver
1055 that is capable of rotating the fiber producing device.
Coupling member 1050 may be an elongated member extending from the
body which may be coupled to a portion of the driver (e.g., a chuck
or a universal threaded joint of the driver). Alternatively,
coupling member may be a receiver, as depicted in FIG. 17C, which
will accept an elongated member from a driver (e.g., the coupling
member may be a chuck or a universal threaded joint).
[0117] In some embodiments, it may be desirable to control the
spacing between the chambers. For example, as depicted in FIG. 17C,
the levels are spaced apart from each other based on the size of
the coupling portions. However, the coupling portions may not
create a sufficient spacing to provide the desired separation of
the levels. In some embodiments, a spacer 1060, may be used to
create additional separation between the levels, as depicted in
FIG. 17B. Use of spacers may help reduce the number of chambers
needed to customize the fiber producing device.
[0118] In some embodiments, the fiber producing device of FIG. 17C
may be top mounted, as shown in FIG. 17D. Fiber producing device
1000 may be coupled to an upper support 1060 using coupling member
1030. Coupling member 1030 may be used to couple fiber producing
device 1000 to a coupling element 1042 of a driver 1040 (e.g., a
chuck coupler or a universal threaded joint of the driver).
Alternatively, coupling member may be a receiver which will accept
an elongated member from a driver (e.g., the coupling member may be
a chuck or a universal threaded joint). Coupling element 1042 of
driver may interact with coupling member 1030 of the fiber
producing device to allow the coupling member to be adjustably
positionable in the coupling element such that the distance between
the fiber producing device and the driver is alterable. This may be
useful for applications where the produced fibers are delivered to
a substrate positioned below the fiber producing device. Assuming
the substrate and driver are at a fixed distance from each other,
altering the vertical distance between the fiber producing device
and the driver also alters the vertical distance between an
underlying substrate and the fiber producing device. Being able to
alter the distance between the underlying substrate and the fiber
producing device allows the fiber deposition patterns to be altered
and customized for different substrates.
[0119] Another example of a multiple chamber fiber producing system
is depicted in FIG. 18. Fiber producing device 1000 includes a body
having two or more chambers, as described with respect to FIGS. 17A
and 17B. Each of the chambers includes one or more openings that
allow material to be placed into the chambers. Each chamber further
includes one or more openings through which material disposed in
the chambers may be ejected. During use, rotation of the fiber
producing device causes material to be ejected through one or more
of the openings of each chamber that includes material to produce
fibers. In some embodiments, openings may have a size and/or shape
that cause the creation of microfibers and/or nanofibers by
ejecting of the material through the openings. In some embodiments,
one or more outlet elements may be coupled to one or more openings.
If different materials are placed in different chambers, two or
more different fibers may be simultaneously produced.
[0120] Fiber producing device 1000 may be incorporated into a fiber
producing system that includes at least one material feed assembly
1070 and, optionally, a heating device 1080. During use, material
may be fed through material feed assembly 1070 into the chambers.
The use of a material feed assembly may allow substantially
continuous use of a multi-level fiber producing device. While
material feed assembly 1070 is depicted as a single tube feeder
that feeds the same material to each chamber, it should be
understood that the material feed assembly may be modified to
include multiple tubes, each tube leading to a separate chamber, to
allow simultaneous addition of different materials to each chamber.
Heating device 1080 may be positioned proximate to the chambers to
provide heat to each of the chambers. The system may also provide
an upper support 1090 for the drive shaft 1095, to help minimize
vibration and provide balancing of the system.
[0121] An alternate embodiment of a fiber producing system is
depicted in FIG. 19. In this embodiment, a fiber producing device
1100 includes a support member 1110 that includes two or more
support elements 1120 coupled to the support member. At least one
of the support elements 1120 is capable of holding a body 1130
containing a material to be spun into microfibers and/or
nanofibers. Support member also includes a central coupling member
1140 that is couplable to a driver. Coupling member 1140 may be an
elongated member extending from the body which may be coupled to a
portion of the driver (e.g., a chuck or a universal threaded joint
of the driver), as depicted in FIG. 19. Alternatively, coupling
member may be a receiver which will accept an elongated member from
a driver (e.g., the coupling member may be a chuck or a universal
threaded joint).
[0122] In one embodiment, the fiber producing system of FIG. 19
includes one or more support elements 1020 that hold a cylindrical
body 1030 having an outlet element 1050. Outlet element 1050 may be
a nozzle, needle, needle port, or an outlet conduit. During use,
one or more cylindrical bodies 1030 containing a material to be
spun are coupled to support elements 1020. For example, cylindrical
body 1030 may be inserted into a complementary cylindrical support
element 1020 having an opening to allow the outlet element to
extend from the support element. Alternatively, support element may
be a ring coupled to support member 1110 that couples with an end
portion of body 1030. Support element 1020 is pivotable to allow
the position of a body coupled to support element to pivot during
rotation. Rotation of support member 1110 causes material to be
ejected from one or more of bodies 1030 to produce microfibers and
or nanofibers. In some embodiments, less than all of the support
elements may receive a body. In such circumstances a counterweight
(e.g., a body that has a weight substantially equal to a filled
body) may be placed in an opposing support element to maintain
balance for the system. Generally, the fiber producing device of
FIG. 19 is very similar to a tube centrifuge in operation.
[0123] Fibers created using the fiber producing devices described
herein may be collected using a variety of fiber collection
devices. Various exemplary fiber collection devices are discussed
below, and each of these devices may be combined with one another.
The simplest method of fiber collection is to collect the fibers on
the interior of a collection wall that surrounds a fiber producing
device. Fibers are typically collected from collection walls as
nonwoven fibers.
[0124] The aerodynamic flow within the chamber influences the
design of the fiber collection device (e.g., height of a collection
wall or rod; location of same). The spinning fiber producing device
develops an aerodynamic flow within the confinement of the
apparatuses described herein. This flow may be influenced by, for
example, the speed, size and shape of the fiber producing device as
well as the location, shape, and size of the fiber collection
device. An intermediate wall placed outside the collection wall may
also influence aerodynamic flow. The intermediate wall may
influence the aerodynamic flow by, for example, affecting the
turbulence of the flow. Placement of an intermediate wall may be
necessary in order to cause the fibers to collect on the fiber
collection device. In certain embodiments, placement of an
intermediate wall can be determined through experimentation. In an
embodiment, a fiber producing device is operated in the presence of
a fiber collection device and an intermediate wall, observing
whether or not fibers are collected on the fiber collection device.
If fibers are not adequately collected on the fiber collection
device, the position of the intermediate wall is moved (e.g.,
making its diameter smaller or larger, or making the intermediate
wall taller or shorter) and the experiment is performed again to
see if adequate collection of fibers is achieved. Repetition of
this process may occur until fibers are adequately collected on the
fiber collection device.
[0125] Typically, fibers are collected on a collection wall or
settle onto other designed structure(s). Temperature also plays a
role on the size and morphology of the formed fibers. If the
collection wall, for example, is relatively hotter than the ambient
temperature, fibers collected on the collection wall may coalesce,
leading to bundling of and/or welding of individual fibers. In some
embodiments, the temperature of the collection wall and/or
intermediate wall may be controlled, such as, for example, by
blowing gas (e.g., air, nitrogen, argon, helium) between the
intermediate wall and the collection wall. By controlling the flow
rate, type, and temperature of this blowing gas, it is possible to
control the temperature and morphology of the fibers. Wall
parameters (e.g., height, location, etc.) may also influence the
morphology of the fibers.
[0126] The intermediate wall may also be used to control, adjust,
and/or influence the aerodynamic flow within the apparatus.
Aerodynamic flow typically guides the fibers to rest on one or more
fiber collection devices. If, upon formation, loose fibers float in
an apparatus (due to their very small mass) without coming to rest
on one or more fiber collection devices, it is likely that, for
example, the intermediate wall is not positioned correctly, or the
fiber collection device(s) is not correctly positioned, and/or the
aerodynamic flow is not properly understood. An intermediate wall
is typically taller than any collection wall that may be used
(e.g., about 1.1 to about 3 times as high as the collection wall).
The intermediate wall may surround a collection wall at a distance
of from about 1 inch to about 5 inches, or from about 2 inches to
about 4 inches, or about 3 inches. Intermediate wall may be about
10% to about 30% larger (e.g., 20% larger) than the collection
wall. An intermediate wall may be segmented, and may have one or
more holes in it.
[0127] FIG. 20A shows a top view of a fiber producing system that
includes a fiber producing device and a collection wall. FIG. 20B
shows a projection view of a fiber producing system that includes a
fiber producing device and a collection wall. As depicted, fiber
producing device 1200 is spinning clockwise about a spin axis, and
material is exiting openings 1206 of the body as fibers 1220 along
various pathways 1210. The fibers are being collected on the
interior of the surrounding collection wall 1240.
[0128] FIG. 21A depicts a perspective view of a fiber producing
system 1300 that includes a collection system 1310 having a
plurality of collection elements 1312a. Fiber producing system 1300
includes a fiber producing device 1320 that includes a body and one
or more outlet elements coupled to the body, as has been previously
described. The body of fiber producing device 1320 is coupled to a
driver (not shown) that is capable of rotating the body. At least
partially surrounding fiber producing device 1320 is a collection
system 1310. In an embodiment, collection system 1310 collects
fibers produced during rotation of fiber producing device 1320.
Collection system 1310 includes one or more collection elements
1312a coupled to a collection system substrate 1314. In an
embodiment, one or more of collection elements 1312a are in the
form of a projection extending from the collection system substrate
1314. Collection elements may be in the form of straight
projections 1312a extending from the collection system substrate
1314. In an embodiment, one or more collection elements comprise a
projection comprising a substantially flat longitudinal surface
1313 extending from the collection element substrate to a distal
end of the collection element. Use of collection elements having a
flat surface assist in stopping the produced fibers without
breaking the fibers, allowing longer fibers to be collected. One or
more coatings (e.g., a teflon coating)" may be applied to the
collection elements to reduce sticking of the fibers to the
collection elements.
[0129] In an alternate embodiment, a collection element 1312b is in
the form of an arcuate projection, for example, as depicted in FIG.
21B. Use of arcuate projections provides a surface for the produced
fibers to collect. Having an inward curved portion (curved toward
the fiber producing device) at the top of the projections helps to
retain the fibers on the projections.
[0130] In an embodiment, fiber producing system 1300 also includes
a collection container 1330. Collection system 1310 and fiber
producing device 1320 are positioned in collection container 1330.
Collection container 1330 allows the system to be enclosed to
inhibit the loss of fibers during production. A collection
container lid (not shown) may be disposed on the collection
container to create a fully enclosed system.
[0131] Collection elements 1312a may be removably coupled to
collection system substrate 1314 through one or more openings 1315
formed in the collection element substrate. For example, as shown
in FIG. 21, a plurality of openings may be formed in the collection
element substrate 1314. Collection elements 1312a may be coupled to
the collection system substrate 1314 via openings 1315. For
example, a collection element 1312a may include a coupling portion
that is insertable into the openings 1315 formed in the collection
element substrate 1314. The coupling portion of collection element
1312 may be threaded and attachable by mating with a threaded
opening formed in collection element substrate 1314. Alternatively,
openings 1315 may extend through the substrate such that a coupling
portion of collection element 1312a may extend through collection
element substrate 1314. Collection element 1312a may be secured by
a coupling member attached to the coupling portion on the underside
of the substrate. Removably coupling collection elements allows the
configuration and position (e.g., the distance from the fiber
producing device) of the collection elements to be altered.
[0132] In an alternate embodiment, collection elements may be
coupled to a collection substrate that allows the collection
elements to be repositioned without having to remove the collection
elements from the substrate. In one embodiment, a plurality of
grooves is formed in the collection system substrate. Collection
elements are coupled to the grooves and are movable along the
grooves. In one embodiment, collection elements may be loosened
from the substrate without removing the collection elements from
the substrate. For example, loosening a nut connecting a bolt from
the collection element to the substrate may allow the collection
element to be moved along the groove. Once positioned, the nut may
be retightened to secure the collection element in place.
[0133] An alternate embodiment of a collection system is depicted
in FIGS. 22A and 22B. Collection system 1400 includes a collection
substrate 1410 that includes at least a first disk 1412 and a
second disk 1414. First disk 1412 includes a plurality of grooves
1413 and second disk 1414 includes a plurality of grooves 1415.
First disk 1412 is coupled to second disk 1414 such that portions
of the grooves of the first and second disks are aligned, as
depicted in FIG. 22A. Grooves 1413 of first disk 1412 are formed
extending radially in a direction from the center of the first
disk. Grooves 1415 of second disk 1414 are formed such that, when
the centers of the first disk and second disk are coupled together,
grooves 1415 of the second disk are at an angle with respect to
grooves 1413 of the first disk. In some embodiments, grooves 1415
on second disk 1413 form an angle of about 45 with respect to
grooves 1413 on first disk 1412, when the first disk and the second
disk are coupled together. Collection elements 1420 are coupled to
first disk 1412 and second disk 1414. In one embodiment, a coupling
portion 1422 of collection element 1420 extends through one of
grooves 1413 in first disk 1412 and one of grooves 1415 of second
disk 1414, as depicted in FIG. 22B. Coupling portion 1422 may
include a fastener 1423 coupled to the coupling portion to help
inhibit removal of collection element 1420 from collection
substrate 1410. With collection elements 1420 coupled to first disk
1412 and second disk 1414, the position of the collection elements
may be altered by rotating the first disk with respect to the
second disk. For example, in the embodiment depicted in FIG. 22A,
as first disk 1412 is rotated in a clockwise direction, collection
elements 1420 are forced along groove 1413 of the first disk and
groove 1415 of second disk 1414 to a position further away from the
center of the disks. In this manner, the effective diameter of the
collection system (i.e., the distance the collection elements are
from the center of the collection substrate) may be increased by
clockwise of first disk 1412. To decrease the effective diameter of
the collection system, first disk 1412 may be rotated in a
counter-clockwise direction, causing collection elements 1420 to
move toward the center of the first and second disks.
[0134] An alternate collection system is depicted in FIGS. 23A-23C.
In an embodiment, a fiber producing device and a collection system
are placed in a collection container. The collection system
includes one or more collection elements coupled to a collection
substrate. The collection substrate may be removably positionable
within the collection container to adjust the position of the
collection elements. In one embodiment, the collection elements are
arcuate projections extending from the collection substrate, as
previously described. FIG. 23A depicts an embodiment of a
collection container 1500 capable of receiving a collection
substrate. For example, a collection container 1500 may include one
or more indentations 1510, configured to mate with one or more
collection tabs formed on a collection substrate. FIG. 23B depicts
a collection substrate 1520 having collection tabs 1525 that may be
used to couple the collection substrate to collection container
1500. For example, tabs 1525 of collection substrate may be matched
with indentations 1510 of collection container 1500 to allow the
collection substrate to be removably positioned in the collection
contained. FIG. 23C depicts collection substrate 1520 placed in a
collection container 1500.
[0135] When desired, collection substrate 1520 may be removed from
collection container 1500 and an alternate collection substrate may
be placed in the collection container. For example, a collection
substrate that includes collection elements that are closer or
farther from the center of the collection container. In other
embodiments, the collection substrate may be removed from the
collection container and replaced with a collection substrate
having collection elements positioned in different positions than
the removed collection substrate. In this manner, the orientation
of the collection elements may be modified without having to
individually remove collection elements.
[0136] For many applications, it may be desirable to substantially
continuously produce nanofibers and/or microfibers. For fiber
producing systems that make use of fiber collection elements, the
removal of fiber from the collection system typically requires a
stoppage of fiber production to allow removal of fibers from the
collection elements. In an alternate embodiment a diversion device
may be used to allow fiber production to continue while the
produced fibers are being collected. FIG. 24 depicts an embodiment
of a fiber producing system 1600 that includes a fiber producing
device 1610 and a diversion device 1620 positionable between the
fiber producing device and collection elements 1630. As fibers are
produced by the fiber producing device 1610, the fibers may be
collected on collection elements 1630 that are disposed around the
fiber producing device. As the amount of fiber collected on
collection elements 1630 increases, the collection elements may
reach a point that the fibers are no longer being collected on the
collection element and instead are being deposited inside the
interior of the system. At this point the fibers may need to be
removed from the collection element before further collection of
the fibers may be accomplished. In an embodiment, a diversion
device 1620 may be positioned between fiber producing device 1610
and the collection elements 1630 to divert the fibers being
produced by the fiber producing device into a collection container
1640. While the fibers are diverted, material from collection
elements 1630 may be removed and collected. Once collection
elements 1630 are sufficiently cleared, diversion device 1620 may
be removed and collection of the fibers on collection elements 1630
may be continued. In this way fiber collection may be accomplished
without stopping the fiber producing device. The diverted fibers
collected in the collection container may be used to form products,
or recycled by combining with unspun material to form a material
feed for the fiber producing device. In this manner, waste of
material may be minimized.
[0137] Diversion may also be used at startup of the fiber producing
system. For example, when rotation of the fiber producing device is
initiated, the fibers being produced may not meet the desired
specifications regarding size and/or consistency. The diversion
device may be positioned between the fiber producing device and the
collection elements in order to divert the produced fibers until
the desired quality requirements are met, typically after a
predetermined time. Once the desired fibers are being produced the
diversion system may be removed to allow the fibers to be collected
on the collection elements. The diverted material may be disposed
of, reintroduced into the fiber producing device, or blended with
unused material to form a material feed for the fiber producing
device.
[0138] The conditions of the environment in which fibers are
created may influence various properties of those fibers. For
example, some metallic fibers, such as iron fibers, react with
ambient air (becoming converted to iron oxides). For such
applications, it is preferable to replace ambient air with an inert
gas (e.g., nitrogen, helium, argon). Humid conditions may
detrimentally affect the surfaces of many polymeric fibers, such as
poly (ethylene oxide) (PEO) fibers. Thus, lowering humidity levels
is preferable for processing of some materials. Similarly, drugs
may be required to be developed under sterile conditions that are
not maintained in ambient conditions, a sterile environment is
therefore preferred in such situations.
[0139] The "environment" refers to the interior space defined by
the housing that surrounds the components of a fiber producing
device. For certain uses, the environment may simply be ambient
air. Air may be blown into the environment, if desired. For other
uses, the environment may be subjected to low-pressure conditions,
such as from about 1 mm Hg to about 760 mm Hg, or any range
derivable therein using, for example, a vacuum pump. Alternatively,
the environment may be subjected to high-pressure conditions, such
as conditions ranging from 761 mm Hg up to 4 atm or higher using,
for example, a high pressure pump. The temperature of the
environment may be lowered or raised, as desired, through the use
of heating and/or cooling systems, which are described below. The
humidity level of the environment may be altered using a
humidifier, and may range from 0% to 100% humidity. For certain
applications, such as drug development, the environment may be
rendered sterile. If the components of an apparatus are each made
of, for example, stainless steel, all components may be
individually sterilized and assembled, such as in a clean room
under conditions that maintain the sterility of the apparatus.
[0140] Several types of heating and cooling sources may be used in
apparatuses and methods as discussed herein to independently
control the temperature of, for example, a fiber producing device,
a collection wall, an intermediate wall, a material, and/or the
environment within an apparatus. Examples of heat sources that may
be employed include resistance heaters, inductive heaters and
radiant heaters (e.g. infrared heaters). Peltier or Thermoelectric
Cooling (TEC) devices may be used for heating and/or cooling
purposes. Cold gas or heated gas (e.g., air or nitrogen) may also
be pumped into the environment for cooling or heating purposes.
Conductive, convective, or radiation heat transfer mechanisms may
be used for heating and cooling of various components of the
apparatuses.
[0141] FIG. 25 shows a perspective view of an embodiment of a fiber
producing system 1700. System 1700 includes a fiber producing
device disposed in a collection container 1710 as has been
previously described. Collection container 1710 is positioned in
housing 1720, which creates an enclosed environment for fiber
production. Driver 1730, such as a variable speed motor, is coupled
to a fiber producing device disposed in collection container 1710.
A heating unit (not shown) is enclosed within housing 1720 and
directs heat (thermal energy) to the fiber producing device and/or
the environment. While a single fiber producing system is depicted
in the housing, it should be understood that multiple fiber
producing systems may be disposed in the same housing. In some
embodiments, multiple fiber producing systems may be coupled to
multiple drivers and disposed in a housing. In some embodiments,
multiple fiber producing systems may be coupled to a single driver,
for example, on a single driver axel that is coupled to the
multiple fiber producing devices.
[0142] An inlet port 1740 is coupled to housing 1720, extending
into the interior of the housing. Inlet port 1740 may be used to
input gasses (e.g., gases such as air, nitrogen, helium, argon,
etc.) into the internal environment of housing 1720, or allows
gasses to be pumped out of the internal environment of the housing
1720. Inlet port 1740 may also include one or more conduits for
conveying material to the fiber producing device. For example, a
fiber producing device may include an opening in the top surface of
the device, as has been shown previously. Alignment and/or coupling
of an inlet tube with the opening may allow material to be sent to
the fiber producing device when the device is being prepared to be
used, or while the device is spinning (to allow continuous
production of fibers) while the housing is closed.
[0143] Indicators for power and electronics and control switches
1750 are positioned on the exterior of a wall of housing 1720. A
control system of the fiber producing system may allow a user to
change certain parameters (e.g., RPM, temperature, and environment)
to influence fiber properties. One parameter may be changed while
other parameters are held constant, if desired. One or more control
boxes in an apparatus may provide various controls for these
parameters, or certain parameters may be controlled via other means
(e.g., manual opening of a valve attached to a housing to allow a
gas to pass through the housing and into the environment of an
apparatus). It should be noted that the control system may be
integral to the apparatus (as shown in FIG. 25) or may be separate
from the housing. For example, a control system may be modular with
suitable electrical connections to the fiber producing system.
[0144] Components of apparatuses may be made from a variety of
materials. In certain embodiments, the components of an apparatus
may be made from stainless steel. For example, the fiber producing
device, collection wall and housing may each be made from stainless
steel. In this situation, the components may be used for, e.g., low
melting metals like tin (232.degree. C.), zinc (420.degree. C.),
silver (962.degree. C.) and alloys thereof. In certain embodiments,
ceramic components may be used for high melting alloys, such as
gold (1064.degree. C.) and nickel (1453.degree. C.). Manipulation
of high melting alloys may require blanketing the environment of
the components with an inert gas, such as nitrogen or helium, with
appropriate sealing of the housing.
[0145] In certain methods described herein, material spun in a
fiber producing device may undergo varying strain rates, where the
material is kept as a melt or solution. Since the strain rate
alters the mechanical stretching of the fibers created, final fiber
dimension and morphology may be significantly altered by the strain
rate applied. Strain rates are affected by, for example, the shape,
size, type and RPM of a fiber producing device. Altering the
viscosity of the material, such as by increasing or decreasing its
temperature or adding additives (e.g., thinner), may also impact
strain rate. Strain rates may be controlled by a variable speed
fiber producing device. Strain rates applied to a material may be
varied by, for example, as much as 50-fold (e.g., 1000 rpm to
25,000 RPM).
[0146] Temperatures of the material, fiber producing device and the
environment may be independently controlled using a control system.
The temperature value or range of temperatures employed typically
depends on the intended application. For example, for many
applications, temperatures of the material, fiber producing device
and the environment typically range from -4.degree. C. to
400.degree. C. Temperatures may range as low as, for example,
-20.degree. C. to as high as, for example, 2500 C. For melt
spinning of polymers, a fiber producing device may be kept at a
temperature of up to 200.degree. C. For melt spinning involving
metals, a fiber producing device may be kept at temperatures of
450.degree. C. or higher. For solution spinning, ambient
temperatures of the fiber producing device are typically used. In
drug development studies the temperature of the fiber producing
device may be between, for example, 4.degree. C. and 80.degree. C.
When producing ceramic or metal fibers, the temperatures utilized
may be significantly higher. For higher temperatures, it will
typically be necessary to make appropriate changes in the materials
of the housing of an apparatus and/or the interior components
(e.g., substitution of metal for plastic), or in the apparatus
itself (e.g., addition of insulation). Such changes may also help
avoid undesirable reactions, such as oxidation.
[0147] The level of material in the fiber producing device may be
monitored by a control system. In an embodiment, inlet port 1730
may include one or more fluid sensors that are positioned proximate
to the fiber producing device, in a position that allows the fluid
sensor to measure the level of fluid in the fiber producing device.
In one embodiment, a fluid sensor is an optical fluid level sensor
that is optically coupled to the fluid in the fiber producing
device. Examples of optical fluid sensors include, but are not
limited to, laser fluid sensors, infrared fluid sensors, and
ultraviolet fluid sensors. Optical fluid sensors include LED based
fluid sensors. In other embodiments, a fluid level sensor is an
ultrasonic fluid level sensor. The fluid sensor may be coupled to a
controller. During use, controller may discontinue production of
fibers if the fluid level in the fiber producing device is below a
predetermined level. In other embodiments, controller may send a
control signal to a material supply source to send more material
into the fiber producing device, if the fluid level inside of the
fiber producing device falls below a predetermined level. Inlet
port 1730 may include one or more conduits coupled to a material
supply source that conveys the material to the fiber producing
device when a control signal is received.
[0148] Generally, it is preferred that fibers produced in a fiber
producing system are collected without being contacted by the
users. An embodiment of a fiber producing system that includes a
collection system is depicted in FIG. 26. Fiber producing system
1800 includes a fiber producing device 1810 coupled to a driver. A
collection system 1820 at least partially surrounds fiber producing
device 1810. Collection system 1820 may include one or more
collection elements 1825 positioned around fiber producing device
1810, a gas flow device 1830, a collection conduit 1835 and a
collection chamber 1840. During use fibers produced by fiber
producing device 1810 are collected on collection elements 1825. As
the amount of fiber collected on collection elements 1825
increases, the collection elements may reach a point that the
fibers begin to be deposited inside collection conduit 1835.
Activation of gas flow device 1830 creates a flow of gas through
the fiber producing system flowing toward a collection chamber
1840. In an embodiment, gas flows from collection elements 1820
toward collection chamber 1840. The flow of gas may dislodge
collected fiber from collection elements 1825 and direct the
dislodged fibers toward collection chamber 1840. In one embodiment,
gas flow device 1830 is activated when the fibers collected on
collection elements 1825 reach a predetermined amount.
Alternatively, gas flow device 1830 may be run continuously as the
fibers are produced. The collection system may further include a
collection conduit 1835 surrounding at least a portion of the fiber
producing device. Collection chamber 1840 is coupled to collection
conduit 1835. Gas flow device 1830 is coupled to collection conduit
1835. Gas produced by gas flow device 1830 creates a current of gas
flowing through collection conduit 1835 toward collection chamber
1840. The produced fibers are transferred through collection
conduit 1835 to collection chamber 1840 by the gas flow produced by
the gas flow device. Collection conduit 1835 may be a separate
conduit formed to conduct the fiber to the chamber. Alternatively,
a wall of a collection container, as described earlier, may define
at least the outer wall of the collection conduit.
[0149] In another embodiment, collection elements 1825 may be
cutting elements (e.g., wires) that are capable of cutting and/or
breaking the fibers that are produced by the fiber producing
device. The wires may extend from a bottom surface of the
collection substrate toward a top surface of the collection system.
The cut or broken fibers are pulled by the gas produced by the gas
flow device, through a collection conduit, into the chamber.
[0150] An embodiment of a fiber producing system that includes a
collection system is depicted in FIG. 27. Fiber producing system
1800 includes a fiber producing device 1810 coupled to a driver. A
collection system 1820 at least partially surrounds fiber producing
device 1810. Collection system 1820 may include one or more
collection elements 1825 positioned around fiber producing device
1810, a gas flow device 1830, a collection conduit 1835 and a
collection chamber 1840. During use fibers produced by fiber
producing device 1810 are collected on collection elements 1825. As
the amount of fiber collected on collection elements 1825
increases, the collection elements may reach a point that the
fibers begin to be deposited inside collection conduit 1835.
Activation of a vacuum device 1845, positioned, e.g., in a
collection chamber creates a flow of gas through the fiber
producing system flowing toward the collection chamber 1840. In an
embodiment, gas flows from collection elements 1820 toward
collection chamber 1840. The flow of gas may dislodge collected
fiber from collection elements 1825 and direct the dislodged fibers
toward collection chamber 1840. In one embodiment, gas flow device
1830 is activated when the fibers collected on collection elements
1825 reach a predetermined amount. Alternatively, gas flow device
1830 may be run continuously as the fibers are produced. The
collection system may further include a collection conduit 1835
surrounding at least a portion of the fiber producing device.
Collection chamber 1840 is coupled to collection conduit 1835. Gas
flow device 1830 is coupled to collection conduit 1835. A vacuum
device 1845 creates a current of gas flowing through collection
conduit 1835 toward collection chamber 1840. The produced fibers
are transferred through collection conduit 1835 to collection
chamber 1840 by the gas flow produced by the gas flow device.
Collection conduit 1835 may be a separate conduit formed to conduct
the fiber to the chamber. Alternatively, a wall of a collection
container, as described earlier, may define at least the outer wall
of the collection conduit.
[0151] In another embodiment, collection elements 1825 may be
cutting elements (e.g., wires) that are capable of cutting and/or
breaking the fibers that are produced by the fiber producing
device. The wires may extend from a bottom surface of the
collection substrate toward a top surface of the collection system.
The cut or broken fibers are pulled by the gas produced by the gas
flow device, through a collection conduit, into the chamber.
[0152] Another embodiment of a fiber producing system is depicted
in FIG. 28. Fiber producing system 1900 includes a fiber producing
device 1910. Fiber producing device includes a body 1912 and a
coupling member 1914. Body 1912 comprises one or more openings 1916
through which material disposed in the body may pass through during
use. One or more outlet elements 1918 (e.g., nozzles, needles,
needle ports or outlet conduits) may be coupled to one or more
openings 1916. As discussed previously, interior cavity of the body
may include angled or rounded walls to help direct material
disposed in body 1912 toward openings 1916. Coupling member 1914
may be an elongated member (as depicted in FIG. 28) extending from
the body which may be coupled to a portion of a driver 1920 (e.g.,
a chuck or a universal threaded joint of the driver).
Alternatively, coupling member may be a receiver which will accept
an elongated member from a driver (e.g., the coupling member may be
a chuck or a universal threaded joint).
[0153] Fiber producing system may include a driver 1920 coupled to
coupling member 1914. Driver 1920 is positioned above fiber
producing device 1910 when the fiber producing device is coupled to
the driver. Driver 1920 is capable of rotating fiber producing
device 1910 during use. Suitable drivers include commercially
available variable electric motors, such as a brushless DC
motor.
[0154] Fiber producing system 1900 may further include a collection
system 1930. Collection system may include a collection wall 1932
at least partially surrounding fiber producing device 1910.
Collection system 1930 may further include a collection conduit
1934 coupled to collection wall 1932. Collection conduit 1934, in
one embodiment, may be an integral part of collection wall 1932.
During use, fibers produced by fiber producing device 1910 may
collect on collection wall 1932 and be transferred to collection
conduit 1934. In one embodiment, collection conduit 1934 is
positioned below fiber producing device 1910 such that the produced
fibers are collected on collection wall 1932 and fall into the
collection conduit. In some embodiments, a gas flow device (not
shown) or a vacuum system (not shown) may be used to create a gas
stream conducting fibers from collection wall 1932 toward
collection conduit 1934. Collection conduit 1934 may be coupled to
a collection chamber that is used to collect fibers.
[0155] In an embodiment, a fiber producing system may be used to
deposit microfibers and/or nanofibers on a substrate. An embodiment
of a deposition system 2000 configured for deposition of fibers on
a substrate is shown in FIG. 29. Any fiber producing device, as
described previously may be coupled to deposition system 2000.
Deposition system 2000 includes an inlet conduit 2010 and a
substrate support 2020. Inlet conduit 2010 may be coupled to either
a fiber producing device, or a collection chamber that collects
fibers from a fiber producing device. During use fibers are
conducted through inlet conduit 2010 into deposition system 2000
where the microfibers and/or nanofibers produced by the fiber
producing device are deposited onto a substrate 2030. A substrate
2030 may be held in a fixed position by substrate support 2020.
Substrate support 2020 may position substrate 2030 in a flow of
microfibers and/or nanofibers created in deposition system
2000.
[0156] In an embodiment, a flow of fibers may be created using a
gas flow system, a vacuum, or a combination of a gas flow system
and vacuum. For example, in one embodiment, a gas flow generator
2040 may be disposed in a bottom of deposition system 2000. During
use a flow of gas is created, flowing from the bottom of deposition
system 2000 toward substrate 2030. The fibers that are generated
and passed to deposition system 2000 are directed into the
substrate by the gas flow. Alternatively, a fiber collection system
coupled to inlet conduit 2010 may produce a gas flow, as described
above, that causes a stream of fibers to flow through the inlet
conduit into deposition system 2000. A fiber deflector 2012 may be
coupled to inlet conduit 2010 to direct incoming fibers toward
substrate 2030.
[0157] In an alternate embodiment, a vacuum device 2022 is coupled
to deposition system 2000. In an embodiment, vacuum system 2022 is
coupled to substrate support 2020. During use, a vacuum is applied
to an upper chamber 2025 formed between substrate support 2020 and
the top of deposition system 2000. A lower chamber 2045 is defined
by substrate support 2020 and the bottom of deposition system 2000.
Lower chamber 2045 includes inlet conduit 2010. Substrate support
2020 may have one or more openings 2024 that pass through the
substrate support, coupling upper chamber 2025 to lower chamber
2045. Application of a vacuum to upper chamber 2025 creates a flow
of gas from lower chamber 2045 thorough substrate support 2020, to
upper chamber 2025. Thus fibers disposed in lower chamber are drawn
toward and into substrate 2030 disposed on substrate support 2020.
A vacuum created in upper chamber may also provide a holding force
to hold substrate 2030 against substrate support 2020.
[0158] In an embodiment, both a gas flow device and a vacuum system
may be used together to create a flow of fibers in deposition
system 2000. For example, gas flow device 2040 may be disposed at
the bottom of deposition system 2000, or may be part of the fiber
producing system coupled to the deposition system. Gas flow device
2040 creates a flow of fibers through inlet conduit 2010 into
deposition system 2000 and toward substrate 2030. Deposition system
2000 may also include a vacuum device 2022 coupled to upper chamber
2025. During use, a vacuum is applied to upper chamber 2025
creating a flow of gas from lower chamber 2045 toward the upper
chamber. Gas coming in from gas flow device 2040 or from inlet
conduit, helps provide a gas flow from lower chamber 2045 toward
the substrate 2030. The fibers directed to substrate 2030, in some
embodiments, may become at least partially embedded in the
substrate.
[0159] In an embodiment, deposition system 2000 may be used to
deposit microfibers and/or nanofibers on a moving substrate. In an
embodiment, substrate support 2020 may allow substrate 2030 to be
moved through deposition system 2000, positioning the portion of
the substrate that is disposed in the deposition system in a flow
of microfibers and/or nanofibers. In an embodiment, a substrate
2030 may be a sheet of material having a length that is longer than
the length of deposition system 2000. The sheet of material may be
passed through deposition system 2000 at a rate that allows a
predetermined amount of fibers to be deposited on the substrate
before the substrate exits the deposition system. The substrate may
be coupled to a substrate conveyance system that moves the
substrate through the deposition system.
[0160] An alternate embodiment of a continuous feed substrate
deposition system is depicted in FIG. 30. In FIG. 30 deposition of
microfibers and/or nanofibers is performed in the fiber producing
system, rather than in a separate deposition system. For example,
in place of the collection elements described above with respect to
fiber producing systems, fiber producing system 2100 includes a
substrate support 2120 positioned around at least a portion of a
fiber producing device 2110. As depicted in FIG. 30, a substrate
support 2120 may be configured for continuous feeding of a
substrate 2130 past fiber producing device 2110. Alternatively,
substrate support 2120 may hold an entire substrate proximate to
the fiber producing device. In the embodiment depicted in FIG. 30,
substrate support 2120 is curved around at least a portion of fiber
producing device 2110. In some embodiments, substrate support 2120
may be positioned substantially completely around fiber producing
device 2110. Substrate support 2120 includes a substantially
rounded edge that allows continuous feed of the substrate at an
angle. During use, a substrate may be fed through the fiber
deposition system over substrate support 2120. As the substrate is
fed through the fiber producing system, fiber producing device 2110
may be operated to produce microfibers and/or nanofibers that are
deposited on the substrate.
[0161] In an embodiment, to control fiber length, one or more
cutting elements 2150 may be positioned between fiber producing
device 2110 and substrate support 2120. Cutting elements 2150 may
be positioned to cut and/or break fibers, produced by the fiber
producing device prior to the fibers reaching the substrate.
[0162] Fibers represent a class of materials that are continuous
filaments or that are in discrete elongated pieces, similar to
lengths of thread. Fibers are of great importance in the biology of
both plants and animals, e.g., for holding tissues together. Human
uses for fibers are diverse. For example, fibers may be spun into
filaments, thread, string, or rope. Fibers may also be used as a
component of composite materials. Fibers may also be matted into
sheets to make products such as paper or felt. Fibers are often
used in the manufacture of other materials.
[0163] Fibers as discussed herein may be created using, for
example, a solution spinning method or a melt spinning method. In
both the melt and solution spinning methods, a material may be put
into a fiber producing device which is spun at various speeds until
fibers of appropriate dimensions are made. The material may be
formed, for example, by melting a solute or may be a solution
formed by dissolving a mixture of a solute and a solvent. Any
solution or melt familiar to those of ordinary skill in the art may
be employed. For solution spinning, a material may be designed to
achieve a desired viscosity, or a surfactant may be added to
improve flow, or a plasticizer may be added to soften a rigid
fiber. In melt spinning, solid particles may comprise, for example,
a metal or a polymer, wherein polymer additives may be combined
with the latter. Certain materials may be added for alloying
purposes (e.g., metals) or adding value (such as antioxidant or
colorant properties) to the desired fibers.
[0164] Non-limiting examples of reagents that may be melted, or
dissolved or combined with a solvent to form a material for melt or
solution spinning methods include polyolefin, polyacetal,
polyamide, polyester, cellulose ether and ester, polyalkylene
sulfide, polyarylene oxide, polysulfone, modified polysulfone
polymers and mixtures thereof. Non-limiting examples of solvents
that may be used include oils, lipids and organic solvents such as
DMSO, toluene and alcohols. Water, such as de-ionized water, may
also be used as a solvent. For safety purposes, non-flammable
solvents are preferred.
[0165] In either the solution or melt spinning method, as the
material is ejected from the spinning fiber producing device, thin
jets of the material are simultaneously stretched and dried or
stretched and cooled in the surrounding environment. Interactions
between the material and the environment at a high strain rate (due
to stretching) leads to solidification of the material into fibers,
which may be accompanied by evaporation of solvent. By manipulating
the temperature and strain rate, the viscosity of the material may
be controlled to manipulate the size and morphology of the fibers
that are created. A wide variety of fibers may be created using the
present methods, including novel fibers such as polypropylene (PP)
nanofibers. Non-limiting examples of fibers made using the melt
spinning method include polypropylene, acrylonitrile butadiene
styrene (ABS) and nylon. Non-limiting examples of fibers made using
the solution spinning method include polyethylene oxide (PEO) and
beta-lactams.
[0166] The creation of fibers may be done in batch modes or in
continuous modes. In the latter case, material can fed continuously
into the fiber producing device and the process can be continued
over days (e.g., 1-7 days) and even weeks (e.g., 1-4 weeks).
[0167] The methods discussed herein may be used to create, for
example, nanocomposites and functionally graded materials that can
be used for fields as diverse as, for example, drug delivery and
ultrafiltration (such as electrets). Metallic and ceramic
nanofibers, for example, may be manufactured by controlling various
parameters, such as material selection and temperature. At a
minimum, the methods and apparatuses discussed herein may find
application in any industry that utilizes micro- to nano-sized
fibers and/or micro- to nano-sized composites. Such industries
include, but are not limited to, material engineering, mechanical
engineering, military/defense industries, biotechnology, medical
devices, tissue engineering industries, food engineering, drug
delivery, electrical industries, or in ultrafiltration and/or
micro-electric mechanical systems (MEMS).
[0168] Some embodiments of a fiber producing device may be used for
melt and/or solution processes. Some embodiments of a fiber
producing device may be used for making organic and/or inorganic
fibers. With appropriate manipulation of the environment and
process, it is possible to form fibers of various configurations,
such as continuous, discontinuous, mat, random fibers,
unidirectional fibers, woven and nonwoven, as well as fiber shapes,
such as circular, elliptical and rectangular (e.g., ribbon). Other
shapes are also possible. The produced fibers may be single lumen
or multi-lumen.
[0169] By controlling the process parameters, fibers can be made in
micron, sub-micron and nano-sizes, and combinations thereof. In
general, the fibers created will have a relatively narrow
distribution of fiber diameters. Some variation in diameter and
cross-sectional configuration may occur along the length of
individual fibers and between fibers.
[0170] Generally speaking, a fiber producing device helps control
various properties of the fibers, such as the cross-sectional shape
and diameter size of the fibers. More particularly, the speed and
temperature of a fiber producing device, as well as the
cross-sectional shape, diameter size and angle of the outlets in a
fiber producing device, all may help control the cross-sectional
shape and diameter size of the fibers. Lengths of fibers produced
may also be influenced by the choice of fiber producing device
used.
[0171] The temperature of the fiber producing device may influence
fiber properties, in certain embodiments. Both resistance and
inductance heaters may be used as heat sources to heat a fiber
producing device. In certain embodiments, the fiber producing
device is thermally coupled to a heat source that may be used to
adjust the temperature of the fiber producing device before
spinning, during spinning, or both before spinning and during
spinning. In some embodiments, the fiber producing device is
cooled. For example, a fiber producing device may be thermally
coupled to a cooling source that can be used to adjust the
temperature of the fiber producing device before spinning, during
spinning, or before and during spinning. Temperatures of a fiber
producing device may range widely. For example, a fiber producing
device may be cooled to as low as -20 C or heated to as high as
2500 C. Temperatures below and above these exemplary values are
also possible. In certain embodiments, the temperature of a fiber
producing device before and/or during spinning is between about
4.degree. C. and about 400.degree. C. The temperature of a fiber
producing device may be measured by using, for example, an infrared
thermometer or a thermocouple.
[0172] The speed at which a fiber producing device is spun may also
influence fiber properties. The speed of the fiber producing device
may be fixed while the fiber producing device is spinning, or may
be adjusted while the fiber producing device is spinning. Those
fiber producing devices whose speed may be adjusted may, in certain
embodiments, be characterized as variable speed fiber producing
devices. In the methods described herein, the fiber producing
device may be spun at a speed of about 500 RPM to about 25,000 RPM,
or any range derivable therein. In certain embodiments, the fiber
producing device is spun at a speed of no more than about 50,000
RPM, about 45,000 RPM, about 40,000 RPM, about 35,000 RPM, about
30,000 RPM, about 25,000 RPM, about 20,000 RPM, about 15,000 RPM,
about 10,000 RPM, about 5,000 RPM, or about 1,000 RPM. In certain
embodiments, the fiber producing device is rotated at a rate of
about 5,000 RPM to about 25,000 RPM.
[0173] In an embodiment, a method of creating fibers, such as
microfibers and/or nanofibers, includes: heating a material;
placing the material in a heated fiber producing device; and, after
placing the heated material in the heated fiber producing device,
rotating the fiber producing device to eject material to create
nanofibers from the material. In some embodiments, the fibers may
be microfibers and/or nanofibers. A heated fiber producing device
is a structure that has a temperature that is greater than ambient
temperature. "Heating a material" is defined as raising the
temperature of that material to a temperature above ambient
temperature. "Melting a material" is defined herein as raising the
temperature of the material to a temperature greater than the
melting point of the material, or, for polymeric materials, raising
the temperature above the glass transition temperature for the
polymeric material. In alternate embodiments, the fiber producing
device is not heated. Indeed, for any embodiment that employs a
fiber producing device that may be heated, the fiber producing
device may be used without heating. In some embodiments, the fiber
producing device is heated but the material is not heated. The
material becomes heated once placed in contact with the heated
fiber producing device. In some embodiments, the material is heated
and the fiber producing device is not heated. The fiber producing
device becomes heated once it comes into contact with the heated
material.
[0174] A wide range of volumes/amounts of material may be used to
produce fibers. In addition, a wide range of rotation times may
also be employed. For example, in certain embodiments, at least 5
milliliters (mL) of material are positioned in a fiber producing
device, and the fiber producing device is rotated for at least
about 10 seconds. As discussed above, the rotation may be at a rate
of about 500 RPM to about 25,000 RPM, for example. The amount of
material may range from mL to liters (L), or any range derivable
therein. For example, in certain embodiments, at least about 50 mL
to about 100 mL of the material are positioned in the fiber
producing device, and the fiber producing device is rotated at a
rate of about 500 RPM to about 25,000 RPM for about 300 seconds to
about 2,000 seconds. In certain embodiments, at least about 5 mL to
about 100 mL of the material are positioned in the fiber producing
device, and the fiber producing device is rotated at a rate of 500
RPM to about 25,000 RPM for 10-500 seconds. In certain embodiments,
at least 100 mL to about 1,000 mL of material is positioned in the
fiber producing device, and the fiber producing device is rotated
at a rate of 500 RPM to about 25,000 RPM for about 100 seconds to
about 5,000 seconds. Other combinations of amounts of material,
RPMs and seconds are contemplated as well.
[0175] Typical dimensions for fiber producing devices are in the
range of several inches in diameter and in height. In some
embodiments, a fiber producing device has a diameter of between
about 1 inch to about 60 inches, from about 2 inches to about 30
inches, or from about 5 inches to about 25 inches. The height of
the fiber producing device may range from about 1 inch to about 10
inches, from about 2 inches to about 8 inches, or from about 3
inches to about 5 inches.
[0176] In certain embodiments, fiber producing device includes at
least one opening and the material is extruded through the opening
to create the nanofibers. In certain embodiments, the fiber
producing device includes multiple openings and the material is
extruded through the multiple openings to create the nanofibers.
These openings may be of a variety of shapes (e.g., circular,
elliptical, rectangular, square) and of a variety of diameter sizes
(e.g., 0.01-0.80 mm). When multiple openings are employed, not
every opening need be identical to another opening, but in certain
embodiments, every opening is of the same configuration. Some opens
may include a divider that divides the material, as the material
passes through the openings. The divided material may form
multi-lumen fibers.
[0177] In one embodiment, coaxial fibers may be produced using an
outlet element having a two or more coaxial conduits. FIG. 32
depicts an outlet element 3200 having an outer conduit 3210 and an
inner conduit 3220. The inner conduit 3220 is sized and positioned
inside of the outer conduit 3210 such that the material may flow
through the inner conduit and the outer conduit during use. The
outlet element 3200 depicted in FIG. 32 may be part of a needle or
nozzle (e.g., a nozzle tip). The use of an outlet element 3200
having coaxial conduits allows the formation of coaxial fibers.
Different materials may be passed through each of conduits
3210/3220 to produce fibers of mixed materials in which an inner
fiber (produced from the inner conduit) is at least partially
surrounded by an outer fiber (produced from the outer conduit). The
formation of coaxial fibers may allow fibers to be formed having
different properties that are selectable based on the materials
used to form the fibers. Alternatively, the same material passes
through each of conduits 3210/3220 forming a coaxial fiber formed
from the same material.
[0178] In an embodiment, material may be positioned in a reservoir
of a fiber producing device. The reservoir may, for example, be
defined by a concave cavity of the heated structure. In certain
embodiments, the heated structure includes one or more openings in
communication with the concave cavity. The fibers are extruded
through the opening while the fiber producing device is rotated
about a spin axis. The one or more openings have an opening axis
that is not parallel with the spin axis. The fiber producing device
may include a body that includes the concave cavity and a lid
positioned above the body.
[0179] Another fiber producing device variable includes the
material(s) used to make the fiber producing device. Fiber
producing devices may be made of a variety of materials, including
metals (e.g., brass, aluminum, stainless steel) and/or polymers.
The choice of material depends on, for example, the temperature the
material is to be heated to, or whether sterile conditions are
desired.
[0180] Any method described herein may further comprise collecting
at least some of the microfibers and/or nanofibers that are
created. As used herein "collecting" of fibers refers to fibers
coming to rest against a fiber collection device. After the fibers
are collected, the fibers may be removed from a fiber collection
device by a human or robot. A variety of methods and fiber (e.g.,
nanofiber) collection devices may be used to collect fibers.
[0181] Regarding the fibers that are collected, in certain
embodiments, at least some of the fibers that are collected are
continuous, discontinuous, mat, woven, nonwoven or a mixture of
these configurations. In some embodiments, the fibers are not
bundled into a cone shape after their creation. In some
embodiments, the fibers are not bundled into a cone shape during
their creation. In particular embodiments, fibers are not shaped
into a particular configuration, such as a cone figuration, using
gas, such as ambient air, that is blown onto the fibers as they are
created and/or after they are created.
[0182] Present method may further comprise, for example,
introducing a gas through an inlet in a housing, where the housing
surrounds at least the heated structure. The gas may be, for
example, nitrogen, helium, argon, or oxygen. A mixture of gases may
be employed, in certain embodiments.
[0183] The environment in which the fibers are created may comprise
a variety of conditions. For example, any fiber discussed herein
may be created in a sterile environment. As used herein, the term
"sterile environment" refers to an environment where greater than
99% of living germs and/or microorganisms have been removed. In
certain embodiments, "sterile environment" refers to an environment
substantially free of living germs and/or microorganisms. The fiber
may be created, for example, in a vacuum. For example the pressure
inside a fiber producing system may be less than ambient pressure.
In some embodiments, the pressure inside a fiber producing system
may range from about 1 millimeters (mm) of mercury (Hg) to about
700 mm Hg. In other embodiments, the pressure inside a fiber
producing system may be at or about ambient pressure. In other
embodiments, the pressure inside a fiber producing system may be
greater than ambient pressure. For example the pressure inside a
fiber producing system may range from about 800 mm Hg to about 4
atmospheres (atm) of pressure, or any range derivable therein.
[0184] In certain embodiments, the fiber is created in an
environment of 0-100% humidity, or any range derivable therein. The
temperature of the environment in which the fiber is created may
vary widely. In certain embodiments, the temperature of the
environment in which the fiber is created can be adjusted before
operation (e.g., before rotating) using a heat source and/or a
cooling source. Moreover, the temperature of the environment in
which the fiber is created may be adjusted during operation using a
heat source and/or a cooling source. The temperature of the
environment may be set at sub-freezing temperatures, such as
-20.degree. C., or lower. The temperature of the environment may be
as high as, for example, 2500.degree. C.
[0185] The material employed may include one or more components.
The material may be of a single phase (e.g., solid or liquid) or a
mixture of phases (e.g., solid particles in a liquid). In some
embodiments, the material includes a solid and the material is
heated. The material may become a liquid upon heating. In another
embodiment, the material may be mixed with a solvent. As used
herein a "solvent" is a liquid that at least partially dissolves
the material. Examples of solvents include, but are not limited to,
water and organic solvents. Examples of organic solvents include,
but are not limited to: hexanes, ether, ethyl acetate, acetone,
dichloromethane, chloroform, toluene, xylenes, petroleum ether,
dimethylsulfoxide, dimethylformamide, or mixtures thereof.
Additives may also be present. Examples of additives include, but
are not limited to: thinners, surfactants, plasticizers, or
combinations thereof.
[0186] The material used to form the fibers may include at least
one polymer. Polymers that may be used include conjugated polymers,
biopolymers, water soluble polymers, and particle infused polymers.
Examples of polymers that may be used include, but are not limited
to polypropylenes, polyethylenes, polyolefins, polystyrenes,
polyesters, fluorinated polymers (fluoropolymers), polyamides,
polyaramids, acrylonitrile butadiene styrene, nylons,
polycarbonates, beta-lactams, block copolymers or any combination
thereof. The polymer may be a synthetic (man-made) polymer or a
natural polymer. The material used to form the fibers may be a
composite of different polymers or a composite of a medicinal agent
combined with a polymeric carrier. Specific polymers that may be
used include, but are not limited to chitosan, nylon, nylon-6,
polybutylene terephthalate (PBT), polyacrylonitrile (PAN),
poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA),
polyglycolic acid (PGA), polyglactin, polycaprolactone (PCL), silk,
collagen, poly(methyl methacrylate) (PMMA), polydioxanone,
polyphenylene sulfide (PPS); polyethylene terephthalate (PET),
polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF),
polypropylene (PP), polyethylene oxide (PEO), acrylonitrile
butadiene, styrene (ABS), and polyvinylpyrrolidone (PVP).
[0187] In another embodiment, the material used to form the fibers
may be a metal, ceramic, or carbon-based material. Metals employed
in fiber creation include, but are not limited to, bismuth, tin,
zinc, silver, gold, nickel, aluminum, or combinations thereof. The
material used to form the fibers may be a ceramic such as alumina,
titania, silica, zirconia, or combinations thereof. The material
used to form the fibers may be a composite of different metals
(e.g., an alloy such as nitonol), a metal/ceramic composite or a
ceramic oxides (e.g., PVP with germanium/palladium/platinum).
[0188] The fibers that are created may be, for example, one micron
or longer in length. For example, created fibers may be of lengths
that range from about 1 .mu.m to about 50 cm, from about 100 .mu.m
to about 10 cm, or from about 1 mm to about 1 cm. In some
embodiments, the fibers may have a narrow length distribution. For
example, the length of the fibers may be between about 1 .mu.m to
about 9 .mu.m, between about 1 mm to about 9 mm, or between about 1
cm to about 9 cm. In some embodiments, when continuous methods are
performed, fibers of up to about 10 meters, up to about 5 meters,
or up to about 1 meter in length may be formed.
[0189] In certain embodiments, the cross-section of the fiber may
be circular, elliptical or rectangular. Other shapes are also
possible. The fiber may be a single-lumen fiber or a multi-lumen
fiber.
[0190] In another embodiment of a method of creating a fiber, the
method includes: spinning material to create the fiber; where, as
the fiber is being created, the fiber is not subjected to an
externally-applied electric field or an externally-applied gas; and
the fiber does not fall into a liquid after being created.
[0191] Fibers discussed herein are a class of materials that
exhibit an aspect ratio of at least 100 or higher. The term
"microfiber" refers to fibers that have a minimum diameter in the
range of 10 microns to 700 nanometers, or from 5 microns to 800
nanometers, or from 1 micron to 700 nanometers. The term
"nanofiber" refers to fibers that have a minimum diameter in the
range of 500 nanometers to 1 nanometer; or from 250 nanometers to
10 nanometers, or from 100 nanometers to 20 nanometers.
[0192] While typical cross-sections of the fibers are circular or
elliptic in nature, they can be formed in other shapes by
controlling the shape and size of the openings in a fiber producing
device (described below). Fibers may include a blending of multiple
materials. Fibers may also include holes (e.g., lumen or
multi-lumen) or pores. Multi-lumen fibers may be achieved by, for
example, designing one or more exit openings to possess concentric
openings. In certain embodiments, such openings may include split
openings (that is, wherein two or more openings are adjacent to
each other; or, stated another way, an opening possesses one or
more dividers such that two or more smaller openings are made).
Such features may be utilized to attain specific physical
properties, such as thermal insulation or impact absorbance
(resilience). Nanotubes may also be created using methods and
apparatuses discussed herein.
[0193] Fibers may be analyzed via any means known to those of skill
in the art. For example, Scanning Electron Microscopy (SEM) may be
used to measure dimensions of a given fiber. For physical and
material characterizations, techniques such as differential
scanning calorimetry (DSC), thermal analysis (TA) and
chromatography may be used.
[0194] In particular embodiments, a fiber of the present fibers is
not a lyocell fiber. Lyocell fibers are described in the
literature, such as in U.S. Pat. Nos. 6,221,487, 6,235,392,
6,511,930, 6,596,033 and 7,067,444, each of which is incorporated
herein by reference.
[0195] In one embodiment, microfibers and nanofibers may be
produced substantially simultaneously. Any fiber producing device
described herein may be modified such that one or more openings has
a diameter and/or shape that produces nanofibers during use, and
one or more openings have a diameter and/or shape that produces
microfibers during use. Thus, a fiber producing device, when
rotated will eject material to produce both microfibers and
nanofibers. In some embodiments, nozzles may be coupled to one or
more of the openings. Different nozzles may be coupled to different
openings such that the nozzles designed to create microfibers and
nozzles designed to create nanofibers are coupled to the openings.
In an alternate embodiment, needles may be coupled (either directly
to the openings or via a needle port). Different needles may be
coupled to different openings such that needles designed to create
microfibers and needles designed to create nanofibers are coupled
to the openings. Production of microfibers and nanofibers
substantially simultaneously may allow a controlled distribution of
the fiber size to be achieved, allowing substantial control of the
properties of products ultimately produced from the
microfiber/nanofiber mixture.
[0196] After production of fibers is completed, it is desirable to
clean the fiber producing device to allow reuse of the system.
Generally, it is easiest to clean a fiber producing device when the
material is in a liquid state. Once the material reverts to a
solid, cleaning may be difficult, especially cleaning up small
diameter nozzles and or needles coupled to the fiber producing
device. The difficulty, especially with melt spinning, is that
cleanup may also be difficult when the device is at an elevated
temperature, especially if the fiber producing device needs to be
cooled prior to handling for clean up. In some embodiments, a purge
system may be couplable to fiber producing device when the fiber
producing device is heated. A purge system may provide an at least
partial seal between the purge system and the body of a fiber
producing device such that a gas may be directed into the body,
through the purge system, to create a pressurized gas inside of the
body. The purge system, in some embodiments, includes a sealing
member couplable to the body, a pressurized gas source, and a
conduit coupling the pressurized gas source to the sealing
member.
[0197] Purge system may be coupled to an opening of the fiber
producing device used to feed material into the body of the fiber
producing device. In an embodiment, a purge system 3110 is coupled
to body 3120 of a fiber producing device 3100, as depicted in FIG.
31. The purge system is couplable to a body 3102 of the fiber
producing device. Purge system 3110 includes a sealing member 3112
coupled to a gas transfer member 3114. When coupled to body,
sealing member 3112 may form a seal between an opening (depicted in
FIG. 7) of fiber producing device 3100 and the purge system sealing
member 3112 such that pressurized gas 3115 may be sent into the
fiber producing device. During use, gas transfer member may be
coupled to a pressurized gas source through a conduit. The
pressurized gas may force any material disposed in an opening out
of the openings (and any devices coupled to the openings) to clear
material out the fiber producing device. All of the material in the
fiber producing device may be forced out of the openings such that
the fiber producing device is substantially clear of material and
ready for the next use. Alternatively, material may remain in the
fiber producing device after purging, however, the material in the
openings and any devices coupled to the opening may be cleared out.
In this manner the openings, which are generally more difficult to
clean, are cleaned prior to the discontinuation of fiber
production.
[0198] In one embodiment, a material feed inlet is coupled to a
fiber producing device such that material may be substantially
continuously fed to the fiber producing device (as shown in FIG.
25). Material feed line may be coupled to a material supply source.
In an embodiment, material feed inlet may also be coupled to a
purge gas source. One or more valves may be disposed between the
purge gas source, the supply source and the material feed inlet to
allow switching between the material and the purge gas. In an
embodiment, material may pass through the material inlet into the
fiber producing device during fiber production. When fiber
production is to be discontinued, the vales(s) may be switched too
allow purge gas to pass through the material inlet and into the
fiber producing device, driving at least some of the material out
of the openings and any devices coupled to the openings. One or
more of the valves may be coupled to a controller that
automatically performs a purge during a programmed or user selected
shutdown of the system.
[0199] Another embodiment of a fiber producing system is depicted
in FIG. 33. Fiber producing system 3300 includes a fiber producing
device 3310. Fiber producing device includes a body 3312 and a
coupling member 3314. In one embodiment, body 3312 comprises a
first member 3314 and a second member 3316 coupled together.
Alternatively, body 3312 may be a single unitary member. First
member 3314 and second member 3316 together define an internal
cavity 3318. One or more openings 3320 extend through the body
through which material disposed in the body may pass through during
use. One or more outlet elements (e.g., nozzles, needles, needle
ports or outlet conduits) may be coupled to one or more openings
3320. As discussed previously, internal cavity of the body may
include angled or rounded walls to help direct material disposed in
internal cavity 3318 of body 3312 toward openings 3320.
[0200] Coupling member 3330 may be an elongated member extending
from the body. In one embodiment, coupling member 3330 is coupled
to the second member 3316 of body 3312 and extends away from the
second member through internal cavity 3318. Coupling member 3330
may be used to couple fiber producing device 3310 to a coupling
element 3342 of a driver 3340 (e.g., a chuck coupler or a universal
threaded joint of the driver). Alternatively, coupling member may
be a receiver which will accept an elongated member from a driver
(e.g., the coupling member may be a chuck or a universal threaded
joint). Coupling element 3342 of driver may interact with coupling
member 3330 of the fiber producing device to allow the coupling
member to be adjustably positionable in the coupling element such
that the distance between the fiber producing device and the driver
is alterable. This may be useful for applications where the
produced fibers are delivered to a substrate positioned below the
fiber producing device. Assuming the substrate and driver are at a
fixed distance from each other, altering the vertical distance
between the fiber producing device and the driver also alters the
vertical distance between an underlying substrate and the fiber
producing device. Being able to alter the distance between the
underlying substrate and the fiber producing device allows the
fiber deposition patterns to be altered and customized for
different substrates.
[0201] Fiber producing system 3300 may include a driver 3340
coupled to coupling member 3330. Driver 3340 is positioned above
fiber producing device 3330 when the fiber producing device is
coupled to the driver. Driver 3330 is capable of rotating fiber
producing device 3310 during use. Suitable drivers include
commercially available variable electric motors, such as a
brushless DC motor.
[0202] Fiber producing system 3330 may further include a material
delivery system 3350. Material delivery system 3350 includes a
material storage container 3352, a pump 3354, and a conduit 3356
for conducting a liquid mixture to fiber producing device 3310. A
mixture of material in a liquid is stored in storage container
3352. A mixture of material in a liquid may be formed by dissolving
the material in a suitable solvent to form a solution of the
material. The mixture of material in a liquid is transferred to
fiber producing device 3352 using pump 3354 coupled to storage
container 3352. Pump 3352 collects the liquid mixture and creates a
flow of liquid material through conduit 3356. The liquid mixture
enters fiber producing device 3310 from conduit 3356 through an
opening 3313 formed in the fiber producing device. A fluid level
sensor 3358 is optically coupled to the liquid mixture disposed in
the fiber producing device. Fluid sensor 3358 provides a
measurement of the amount of fluid disposed in the fiber producing
device. During use, the pump flow rate may be adjusted based on the
amount of fluid in the fiber producing device. In one embodiment,
material delivery system 3350 substantially continuously delivers
material to fiber producing device 3310 while the fiber producing
device is rotating. Positioning of conduit 3356 outside of the
fiber producing device allows continuous delivery of material while
the fiber producing device is rotating.
[0203] Driver 3340 may be mounted to arm 3360. In one embodiment,
arm 3360 may be coupled to a support (not shown). Arm 3360 may be
coupled to a support such that the arm is movable with respect to
the support. For example, arm 3360 may allow driver 3340 and the
coupled fiber producing device 3310 (referred to as the
"driver/fiber producing device assembly") to be moved (e.g., swung)
away from the substrate to allow maintenance to be performed on the
fiber producing device (e.g., changing the fiber producing device,
purging the fiber producing device, etc. Arm 3360 may also allow
the horizontal position of the driver/fiber producing device
assembly to be altered. In an embodiment, arm 3360 allows the
driver/fiber producing device assembly to be moved along a
horizontal fixed path. This allows the placement of the
driver/fiber producing device assembly to be altered with respect
to an underlying substrate. In some embodiments, a motor may be
coupled to the driver/fiber producing device assembly to allow
automated movement of the driver/fiber producing device assembly
with respect to the substrate.
[0204] In one embodiment, the pattern of fibers deposited by a
fiber producing device 3310 in an inverted configuration, as
described with respect to FIG. 33, may not be sufficient to provide
uniform coverage of the underlying substrate. In order to improve
coverage, the driver/fiber producing device assembly may be
horizontally moved with respect to the substrate to provide a more
even coverage to the underlying substrate. For example, arm may
allow the driver/fiber producing device assembly to be moved along
a fixed horizontal path. When the substrate is positioned below the
fiber producing device, fiber production may be started and the
driver/fiber producing device assembly may be horizontally moved to
produce a more homogenous deposition of fibers on the substrate.
The horizontal movement of the driver/fiber producing device
assembly may be coordinated with the movement of the underlying
substrate through the fiber deposition system. In an alternate
embodiment, the arm may be configured to rotate the driver/fiber
producing device assembly with respect to the substrate. Rotation
of the driver/fiber producing device assembly may allow a more even
distribution of the fibers in the substrate.
[0205] In some embodiments, fiber producing device may be heated.
One or more heating devices 3370 and 3372, may be thermally coupled
to fiber producing device 3310. In some embodiments, a heating
device 3370 may be ring shaped heating device to allow the coupling
member to extend through the heating device. Heating device 3372
may be a planar substrate disposed below the fiber producing device
or ring shaped. In some embodiments, heating devices 3370 and 3372
may have a diameter that is less than the diameter of fiber
producing device 3310. It has been generally found that during
production of fibers, the produced fibers may be drawn to the heat
from the heating devices if the fibers come to close to such
devices. By reducing the diameter of the heating devices to be less
then the diameter of the fiber producing devices, the loss of fiber
due to contact with the heating devices is minimized. Further
details regarding heating devices are described with respect to the
heating device depicted in FIG. 39.
[0206] Another embodiment of a fiber producing system is depicted
in FIG. 34. The fiber producing system depicted in FIG. 34 is
similar to the system depicted in FIG. 33. The system in FIG. 34,
however, is configured for use in melt spinning procedures, while
the system of FIG. 33 is configured for use in solution spinning
procedures. To accommodate melt spinning processes, the material
delivery system 3350 includes a material storage container 3380 and
an extruder 3382. Solid material is stored in material storage
container 3380 and transferred to extruder 3382. Extruder 3382
receives material from material storage container 3380 and melts
the material producing a melt. The melt is transferred to metered
melt pump 3385 that meters and pumps the molten material though the
conduit 3386 to the fiber producing device. Conduit 3386 is formed
of a material capable of transporting the heated material from the
extruder to the fiber producing device. In some embodiments,
conduit 3386 is at least partially surrounded by insulation 3384 to
inhibit cooling of the heated material as it is transferred to the
fiber producing device. Heating devices 3370 and 3372 are used to
keep the fiber producing device at a sufficient temperature to
maintain the material in a melted state.
[0207] In an alternate embodiment, extruder 3382 may be replaced
with a material feed hopper. Material feed hopper may be used to
channel a solid material disposed in material storage container
3380 directly into the fiber producing device. The fiber producing
device may be heated to melt at least a portion of the solid
material that is transferred from the material storage container
into the fiber producing device. Heating devices, as described
previously, may be used to heat the fiber producing device prior to
or after the solid material is placed in the fiber producing
device. In this manner, the use of an extruder and insulated
conduits may be avoided, reducing the energy requirements of the
system.
[0208] A top driven fiber producing system is particularly useful
for depositing fibers onto a substrate. An embodiment of a system
for depositing fibers onto a substrate is shown in FIG. 35.
Substrate deposition system 3500 includes a deposition system 3600
and a substrate transfer system 3550. Deposition system 3600
includes a fiber producing system 3610, as described herein.
Deposition system produces and directs fibers produced by a fiber
producing device toward a substrate 3520 disposed below the fiber
producing device during use. Substrate transfer system moves a
continuous sheet of substrate material through the deposition
system.
[0209] Deposition system 3600, in one embodiment, includes a top
mounted fiber producing device 3610. During use, fibers produced by
fiber producing device 3610 are deposited onto substrate 3520. A
schematic diagram of deposition system 3600 is depicted in FIG. 36.
Fiber deposition system may include one or more of: a vacuum system
3620, an electrostatic plate 3630, and a gas flow system 3640. A
vacuum system produces a region of reduced pressure under substrate
3520 such that fibers produced by fiber producing device 3610 are
drawn toward the substrate due to the reduced pressure.
Alternatively, one or more fans may be positioned under the
substrate to create an air flow through the substrate. Gas flow
system 3640 produces a gas flow 3642 that directs fibers formed by
the fiber producing device toward the substrate. Gas flow system
may be a pressurized air source or one or more fans that produce a
flow of air (or other gas). The combination of vacuum and air flow
systems are used to produce a "balanced air flow" from the top of
the deposition chamber through the substrate to the exhaust system
by using forced air (fans, pressurized air) and exhaust air (fans,
to create an outward flow) and balancing and directing the airflow
to produce a fiber deposition field down to the substrate.
Deposition system 3600 includes substrate inlet 3614 and substrate
outlet 3612.
[0210] An electrostatic plate 3630 is also positioned below
substrate 3520. The electrostatic plate is a plate capable of being
charged to a predetermined polarity. Typically, fibers produced by
the fiber producing device have a net charge. The net charge of the
fibers may be positive or negative, depending on the type of
material used. To improve deposition of charged fibers, an
electrostatic plate may be disposed below substrate 3520 and be
charged to an opposite polarity as the produced fibers. In this
manner, the fibers are attracted to the electrostatic plate due to
the electrostatic attraction between the opposite charges. The
fibers become embedded in the substrate as the fibers move toward
the electrostatic plate.
[0211] A pressurized gas producing and distribution system may be
used to control the flow of fibers toward a substrate disposed
below the fiber producing device. During use fibers produced by the
fiber producing device are dispersed within the deposition system.
Since the fibers are composed primarily of microfibers and/or
nanofibers, the fibers tend to disperse within the deposition
system. The use of a pressurized gas producing and distribution
system may help guide the fibers toward the substrate. In one
embodiment, a pressurized gas producing and distribution system
includes a downward gas flow device 3640 and a lateral gas flow
device 3645. Downward gas flow device 3640 is positioned above or
even with the fiber producing device to facilitate even fiber
movement toward the substrate. One or more lateral gas flow devices
3645 are oriented perpendicular to or below the fiber producing
device. In some embodiment, lateral gas flow devices 3645 have an
outlet width equal to the substrate width to facilitate even fiber
deposition onto substrate. In some embodiments, the angle of the
outlet of one or more lateral gas flow devices 3645 may be varied
to allow better control of the fiber deposition onto the substrate.
Each lateral gas flow devices 3645 may be independently
operated.
[0212] During use of the deposition system, fiber producing device
3610 may produce various gasses due to evaporation of solvents
(during solution spinning) and material gasification (during melt
spinning). Such gasses, if accumulated in the deposition system may
begin to effect the quality of the fiber produced. In some
embodiment, the deposition system includes an outlet fan 3650 to
remove gasses produced during fiber production from the deposition
system.
[0213] Substrate transfer system 3550, in one embodiment, is
capable of moving a continuous sheet of substrate material through
the deposition system. In one embodiment, substrate transfer system
3550 includes a substrate reel 3552 and a take up reel system 3554.
During use, a roll of substrate material is placed on substrate
reel 3552 and threaded through deposition system 3600 to the
substrate take up reel system 3554. During use, substrate take up
reel system 3554 rotates, pulling substrate through deposition
system at a predetermined rate. In this manner, a continuous roll
of a substrate material may be pulled through fiber deposition
system.
[0214] In some embodiments, it may be difficult for a single fiber
producing device to produce a sufficient amount of fibers to
provide a desired level of fibers to an entire substrate. In order
to ensure adequate and even coverage of fibers on a substrate, a
substrate deposition system may include two or more fiber producing
devices, as depicted in FIG. 37. A fiber deposition system 3700 may
include two or more fiber producing devices 3710 coupled to a
driver unit 3720. Driver unit is coupled to fiber producing devices
3710. In one embodiment, driver unit 3720 includes a plurality of
drivers, each driver being coupled to a fiber producing device
3710. The drive unit includes a controller capable of individually
operating each of the drive units such that two or more of the
fiber producing devices substantially simultaneously produce
fibers. In an alternate embodiment, driver unit includes a single
driver that simultaneously operates all of the fiber producing
devices coupled to the driver unit. In such an embodiment, all of
the fiber producing devices substantially simultaneously produce
fibers to ensure complete coverage of the underlying substrate
3730.
[0215] An embodiment of a fiber producing device is depicted in
FIGS. 38A-C. Fiber producing device 3800 includes a body comprising
a first member 3810 (FIG. 38A) and a second member 3820 (FIG. 38B).
First member 3810 includes a first member coupling surface 3812.
First member coupling surface 3812 includes one or more grooves
3814 extending along the width of the first member coupling
surface. Second member 3820 includes a second member coupling
surface 3822 and a coupling member 3828. Second member coupling
surface 3822 comprising one or more grooves 3824 extending along
the width of the second member coupling surface. Coupling member
3828 may be used to couple the body to a driver of a fiber
producing system.
[0216] The body is formed by coupling first member 3810 to second
member 3820. To couple the first and second members, first member
coupling surface 3812 is contacted with second member coupling
surface 3822. One or more fasteners 3830 may be used to secure the
first member and second member together. When the first member
coupling surface is coupled to the second member coupling surface
to form the body, the first member and the second member together
define an internal cavity of the body. In one embodiment, fasteners
3830 have an effect on the pattern of fiber produced by the fiber
producing device. For example, the head of a fastener produces
external gas currents due to the high speed of rotation of the
fiber producing device. Additional components may be added on
either side of the body or incorporated directly onto the surface
of the body to produce external gas currents. These external gas
currents can effect the pattern of fibers produced. The pattern of
fibers produced by the fiber producing device may be altered by
using fasteners having different head configurations.
Alternatively, the position of fasteners may be altered to change
the fiber deposition pattern. For example, the one or more
fasteners may be left out of existing holes. Alternatively, the
body may include a plurality of holes. The pattern of fibers
produced by the fiber producing device may be altered by changing
which of the plurality of holes are used to couple the first and
second members together. In another embodiment. The height of the
fasteners may be altered by loosing and or tightening the
fasteners. Thus the height of the head of one or more fasteners may
be varied to alter the pattern of fibers produced by the fiber
producing device.
[0217] In some embodiments, it is desirable that grooves 3814 of
the first member are substantially aligned with groves 3824 of the
second member. When the grooves are aligned, the grooves together
form one or more openings 3850 extending from the interior cavity
to an outer surface of the body. During use, rotation of the body
material disposed in the internal cavity of the body is ejected
through one or more openings 3850 to produce microfibers and/or
nanofibers. Material may be placed into the body of fiber producing
through a first member opening 3828 formed in first member 3810. In
one embodiment, first member is ring shaped and material is added
to the internal cavity through a central opening of the ring shaped
first member.
[0218] In order to ensure proper alignment of the first member with
the second member, the first member may include a first alignment
element 3816 disposed on the first coupling member surface 3812.
The second member may include a second alignment element 3826
disposed on the second member coupling surface 3822. First
alignment element 3816 couples with second alignment element 3826
when first member 3810 is properly aligned with second member 3820.
This may help to ensure that grooves 3814 and 3824 are properly
aligned. In one embodiment, one of the first or second alignment
elements includes a projection extending form the coupling surface,
and the other of the first or second alignment elements includes an
indentation complementary to the projection.
[0219] In an embodiment, the first alignment element may be a first
alignment ring 3816 disposed on the first coupling member surface
3812. The second member may include a second alignment ring 3826
disposed on the second member coupling surface 3822. First
alignment ring 3816 interlocks with second alignment ring 3826 when
first member 3810 is properly aligned with second member 3820. The
interlocking first and second rings center the first member and
second member with each other. In one embodiment, first and second
rings interlock with each other on an angle so that the first and
second members are centered to one another. Alignment is further
insured by the use of a projection 3840 formed in the first member
which fits into a suitable indentation 3845 formed in the second
member. Projection 3840 and indentation 3845 help ensure that the
first and second members are coupled in the same rotational
position such that the grooves of the first and second members are
aligned.
[0220] In an embodiment, where the fiber producing device is
coupled to a driver positioned above the fiber producing device,
the coupling member extends through the internal cavity defined by
the first and second members and through the first member.
Alternatively, where the fiber producing device is coupled to a
driver positioned below the fiber producing device, the coupling
member is coupled to an outer surface of the second member,
extending away from the second member.
[0221] An embodiment of a multiple layer fiber producing device is
depicted in FIG. 38D. Fiber producing device 3800 includes a body
comprising a first member 3810, a second member 3820, and a third
member 3830. It should be understood that while three members are
shown, any number of members may be coupled together to form a
multiple layer fiber producing device. The body is formed by
coupling first member 3810 to second member 3820 and second member
to third member 3830. Second member includes a second member
coupling surface and an additional coupling surface, disposed on
the side opposite to the second member coupling surface. Both the
second member coupling surface and the second member additional
coupling surface include grooves extending along the width of the
respective surfaces. First and second members couple together by
contacting first member coupling surface with the second member
coupling surface. Grooves of the first member are substantially
aligned with groves of the second member to form one or more
openings 3850 extending from the interior cavity to an outer
surface of the body. Second and third members also couple together
by contacting the second member additional coupling surface with
the third member coupling surface. Grooves of the second member
additional coupling surface are substantially aligned with groves
of the third member coupling surface to form one or more openings
3850 extending from the interior cavity to an outer surface of the
body.
[0222] During use, material disposed in the internal cavity of the
body is ejected through one or more openings 3850 and one or more
openings 3855 to produce microfibers and/or nanofibers. Material
may be placed into the body of fiber producing through a first
member opening formed in first member 3828. In one embodiment,
material is added to the internal cavity through a central opening
of the first member.
[0223] An embodiment of a heating device 3900 is depicted in FIG.
39. One or more heating elements 3910 are coupled to a heating
device substrate 3920. Heating substrate 3920 is formed of a
thermally conductive material (e.g., stainless steel, iron, etc.).
Heating elements 3910 may provide heat to heat substrate 3920.
Substrate 3920 is thermally coupled to one or more components of a
fiber producing system (e.g., a fiber producing device). In one
embodiment, heating elements 3910 may be cartridge heaters that are
disposed within substrate 3920. For example, one or more openings
may be formed in substrate 3920 and the cartridge heaters disposed
in the openings. During use, an electric current may be applied to
one or more of the cartridge heaters to heat the substrate. While
the heating device is depicted as having a ring shaped substrate,
it should be understood that other shapes may be used.
[0224] In an alternate embodiments, a heating device used to heat a
fiber producing device is a radiant heater. An infrared heater is
an example of a radiant heater that may be used to heat a fiber
producing device.
[0225] An embodiment of a fiber producing device is depicted in
FIG. 40. Fiber producing device 4000 includes a body comprising a
first member 4010 and a second member 4020. The body is formed by
coupling first member 4010 to second member 4020. First and second
members couple together by contacting first member coupling surface
with second member coupling surface. In some embodiments, it is
desirable that grooves of the first member are substantially
aligned with groves of the second member. When the grooves are
aligned, the grooves together form one or more openings 4050
extending from the interior cavity to an outer surface of the body.
During use, rotation of the body material disposed in the internal
cavity of the body is ejected through one or more openings 4050 to
produce microfibers and/or nanofibers. Material may be placed into
the body of fiber producing through a first member opening formed
in first member 4010. In one embodiment, first member is ring
shaped and material is added to the internal cavity through a
central opening of the ring shaped first member.
[0226] One or more fasteners 4030 may be used to secure the first
member and second member together. When the first member coupling
surface is coupled to the second member coupling surface to form
the body, the first member and the second member together define an
internal cavity of the body. One or more channels 4028 may be added
on either side of the body surrounding openings 4050 and extending
away from the openings Channels 4028 help alter the external gas
currents produced when the fiber producing device is spinning.
These external gas currents can affect the pattern of fibers
produced and/or the size of the fibers produced. The pattern of
fibers produced by the fiber producing device may be altered by
using channels having different sizes and/or shapes. In some
embodiments, channels 4028 are concave channels that allow the
fiber producing material ejected from the openings to run along the
channel and be ejected at an angle away from the body.
[0227] Fiber producing devices may be formed in different shapes.
Non-limiting examples of fiber producing devices having alternate
shapes are depicted in FIGS. 41A-B and FIG. 42. In an embodiment
depicted in FIG. 41A, fiber producing device 4100 includes a body
that is in the form of a star. The body of the fiber producing
device is composed of a first member 4110 and a second member 4120,
as depicted in FIG. 41B. The body is formed by coupling first
member 4110 to second member 4120. First and second members couple
together by contacting first member coupling surface with second
member coupling surface. In some embodiments, it is desirable that
grooves of the first member are substantially aligned with groves
of the second member. When the grooves are aligned, the grooves
together form one or more openings 4150 extending from the interior
cavity to an outer surface of the body. During use, rotation of the
body material disposed in the internal cavity of the body is
ejected through one or more openings 4150 to produce microfibers
and/or nanofibers. Material may be placed into the body of fiber
producing through a first member opening formed in first member
3810. In one embodiment, material is added to the internal cavity
through a central opening 4140 of the first member. In some
embodiments, each arm of fiber producing device 4100 may have an
aerodynamic profile. The use of an aerodynamic profile may reduce
drag forces on the fiber producing device as the device is spun
during use. Additionally, the profile of the arms may be adjusted
to control the physical properties of the fibers being
produced.
[0228] In another embodiment, a gear shaped fiber producing device,
as depicted in FIG. 42 may be used to produce nanofibers and/or
microfibers. Gear shaped fiber producing device 4200 may be formed
from a single unitary device, or from two or more sperate pieces
that are coupled together as had been described above. Fiber
producing device 4200 includes a plurality of protruding segments
4230 extending from central body 4210. Each segment 4230 is defined
by sidewalls 4232 and 4234. Sidewalls 4232 are substantially
straight, while sidewalls 4234 are curved. The segments 4230 are
positioned such that the straight sidewalls 4232 of a segment are
postioned across from the curved sidewall of an adjacent segment
4234. Thus a gap is formed between the segments having a curved and
straight boundary.
[0229] In contrast to other fiber producing devices, openings 4250
are formed in between the protruding segments 4230, rather than at
the end of the segments. During use, material disposed in the body
of fiber producing device 4200 is ejected through openings 4250.
When the fiber producing device is rotating, the material exits
openings 4250 and is carried to the curved sidewalls 4234. The
material runs along the curved sidewalls and is ejected from the
fiber producing device. The amount of arc on curved sidewalls 4234
may be adjusted to alter the size and/or direction that the fibers
are produced.
APPLICATIONS
[0230] Microfibers and nanofibers produced using any of the devices
and methods described herein may be used in a variety of
applications. Some general fields of use include, but are not
limited to: food, materials, electrical, defense, tissue
engineering, biotechnology, medical devices, energy, alternative
energy (e.g., solar, wind, nuclear, and hydroelectric energy);
therapeutic medicine, drug delivery (e.g., drug solubility
improvement, drug encapsulation, etc.); textiles/fabrics, nonwoven
materials, filtration (e.g., air, water, fuel, semiconductor,
biomedical, etc); automotive; sports; aeronautics; space; energy
transmission; papers; substrates; hygiene; cosmetics; construction;
apparel, packaging, geotextiles, thermal and acoustic
insulation.
[0231] Some products that may be formed using microfibers and/or
nanofibers include but are not limited to: filters using charged
nanofiber and/or microfiber polymers to clean fluids; catalytic
filters using ceramic nanofibers ("NF"); carbon nanotube ("CNT")
infused nanofibers for energy storage; CNT infused/coated NF for
electromagnetic shielding; mixed micro and NF for filters and other
applications; polyester infused into cotton for denim and other
textiles; metallic nanoparticles or other antimicrobial materials
infused onto/coated on NF for filters; wound dressings, cell growth
substrates or scaffolds; battery separators; charged polymers or
other materials for solar energy; NF for use in environmental
clean-up; piezoelectric fibers; sutures; chemical sensors;
textiles/fabrics that are water & stain resistant, odor
resistant, insulating, self-cleaning, penetration resistant,
anti-microbial, porous/breathing, tear resistant, and wear
resistant; force energy absorbing for personal body protection
armor; construction reinforcement materials (e.g., concrete and
plastics); carbon fibers; fibers used to toughen outer skins for
aerospace applications; tissue engineering substrates utilizing
aligned or random fibers; tissue engineering Petri dishes with
aligned or random nanofibers; filters used in pharmaceutical
manufacturing; filters combining microfiber and nanofiber elements
for deep filter functionality; hydrophobic materials such as
textiles; selectively absorbent materials such as oil booms;
continuous length nanofibers (aspect ratio of more than 1,000 to
1); paints/stains; building products that enhance durability, fire
resistance, color retention, porosity, flexibility, anti microbial,
bug resistant, air tightness; adhesives; tapes; epoxies; glues;
adsorptive materials; diaper media; mattress covers; acoustic
materials; and liquid, gas, chemical, or air filters.
[0232] Fibers may be coated after formation. In one embodiment,
microfibers and/or nanofibers may be coated with a polymeric or
metal coating. Polymeric coatings may be formed by spray coating
the produced fibers, or any other method known for forming
polymeric coatings. Metal coatings may be formed using a metal
deposition process (e.g., CVD).
[0233] In this patent, certain U.S. patents, U.S. patent
applications, and other materials (e.g., articles) have been
incorporated by reference. The text of such U.S. patents, U.S.
patent applications, and other materials is, however, only
incorporated by reference to the extent that no conflict exists
between such text and the other statements and drawings set forth
herein. In the event of such conflict, then any such conflicting
text in such incorporated by reference U.S. patents, U.S. patent
applications, and other materials is specifically not incorporated
by reference in this patent.
[0234] Further modifications and alternative embodiments of various
aspects of the invention will be apparent to those skilled in the
art in view of this description. Accordingly, this description is
to be construed as illustrative only and is for the purpose of
teaching those skilled in the art the general manner of carrying
out the invention. It is to be understood that the forms of the
invention shown and described herein are to be taken as examples of
embodiments. Elements and materials may be substituted for those
illustrated and described herein, parts and processes may be
reversed, and certain features of the invention may be utilized
independently, all as would be apparent to one skilled in the art
after having the benefit of this description of the invention.
Changes may be made in the elements described herein without
departing from the spirit and scope of the invention as described
in the following claims.
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