U.S. patent application number 15/081466 was filed with the patent office on 2017-01-26 for enhanced meta-aramid and para-aramid textiles, garments, and methods.
The applicant listed for this patent is Cocona, Inc.. Invention is credited to Wesley Wade Burgess, Gregory W. Haggquist.
Application Number | 20170022634 15/081466 |
Document ID | / |
Family ID | 56977754 |
Filed Date | 2017-01-26 |
United States Patent
Application |
20170022634 |
Kind Code |
A1 |
Haggquist; Gregory W. ; et
al. |
January 26, 2017 |
ENHANCED META-ARAMID AND PARA-ARAMID TEXTILES, GARMENTS, AND
METHODS
Abstract
A textile comprising a plurality of synthetic fibers and a
plurality of active particles. The plurality of synthetic fibers
comprise a plurality of meta-aramid and/or para-aramid fibers. The
plurality of active particles are physically embedded in the
plurality of synthetic fibers. The plurality of active particles
comprise a higher heat stability temperature than the plurality of
synthetic fibers.
Inventors: |
Haggquist; Gregory W.;
(Longmont, CO) ; Burgess; Wesley Wade; (Beech
Mountain, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cocona, Inc. |
Boulder |
CO |
US |
|
|
Family ID: |
56977754 |
Appl. No.: |
15/081466 |
Filed: |
March 25, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62138325 |
Mar 25, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D10B 2401/02 20130101;
D01F 1/07 20130101; A41D 31/08 20190201; A62B 17/003 20130101; A41D
31/12 20190201; A41D 31/102 20190201; D01F 6/605 20130101; D01D
5/06 20130101; A41D 13/0512 20130101; D10B 2501/042 20130101; A41D
2500/50 20130101; D01D 5/38 20130101; D10B 2331/021 20130101 |
International
Class: |
D01F 1/07 20060101
D01F001/07; A41D 13/05 20060101 A41D013/05; D01F 6/60 20060101
D01F006/60; D01D 5/06 20060101 D01D005/06; D01D 5/38 20060101
D01D005/38 |
Claims
1. A textile comprising, a plurality of synthetic fibers, the
plurality of synthetic fibers comprising a plurality of meta-aramid
and/or para-aramid fibers; a plurality of active particles
physically embedded in the plurality of synthetic fibers, wherein
the plurality of active particles comprise a higher heat stability
temperature than the plurality of synthetic fibers.
2. The textile of claim 1 wherein, the textile comprises a first
side and a second side; and the active particles decrease the
humidity and/or an amount of liquid between the first side and a
user's skin upon wearing the textile.
3. The textile of claim 2 wherein, the first side comprises a
textile side nearest to a user's skin upon wearing the textile; and
the second side comprises a textile side farther from the user's
skin upon wearing the textile.
4. The textile of claim 1 wherein, the weight ratio of active
particles to synthetic fibers comprises a range of about to about
0.01% to 3%; and the active particles increase a resistance to
burning for the textile.
5. The textile of claim 4 wherein, the resistance to burning
comprises, a non-melting textile; a non-dripping textile; and a
textile comprising, less than two second of afterglow and after
flame, and less than four inches of char length.
6. The textile of claim 1 wherein, the active particles, are
between about 100 nm and 10 microns in diameter; absorb light
comprising wavelengths from about 8 microns to about 12 microns;
absorb and eject water, wherein the water comprises a temperature
between about 10 degrees Celsius and about 40 degrees Celsius; and
comprise a surface area greater than 10 m.sup.2 per gram of active
particles.
7. The textile of claim 6 wherein, the light comprises infrared
light; and an increased water evaporation rate for the textile when
the active particle is present.
8. The textile of claim 6 wherein, the water evaporation rate
comprises moisture entering the textile at a textile first side and
leaving the textile at a textile second side; a temperature of the
water at the textile first side comprises a temperature near a
user's body temperature; the temperature of the water at the
textile second side comprises an ambient temperature.
9. A fire-resistant garment comprising, a plurality of synthetic
fibers, the plurality of synthetic fibers comprising a plurality of
meta-aramid and/or para-aramid fibers; a plurality of active
particles physically embedded in the plurality of synthetic fibers,
wherein the plurality of active particles comprise a higher heat
stability temperature than the plurality of synthetic fibers.
10. The fire-resistant garment of claim 9 further comprising, a
first garment section; and a second garment section.
11. The fire-resistant garment of claim 10 wherein, one of the
first garment section and the second garment section comprises a
head and/or neck covering; and no skin is exposed to an ambient
environment upon wearing the fire-resistant garment.
12. The fire-resistant garment of claim 9 further comprising, a
plurality of natural porous fibers blended with the plurality of
synthetic fibers; and one or more openings to access a first
garment side from a second garment side.
13. The fire-resistant garment of claim 12 wherein, the plurality
of synthetic fibers doped with active particles comprises cotton
and/or polyester; and the synthetic fibers doped with active
particles is no greater than 35%.
14. A method of creating a composite polymer textile comprising,
creating a solution by dissolving polymers comprising meta-aramids
and/or para-aramids into a solvent; dispersing active particles
into the solution; spinning the solution using a spinneret;
polymerizing or precipitating the solution into a meta-aramid
and/or para-aramid fiber material; and physically incorporating the
active particles into the meta-aramid and/or para-aramid fiber
material.
15. The method of claim 14 wherein, the solvent comprises sulfuric
acid.
16. The method of claim 14 wherein, the active particles are
insoluble and physically unaffected by the solvent.
17. The method of claim 14 wherein, the active particles are
dispersed into the solution before and/or during the spinning of
the solution using a spinneret.
18. The method of claim 14 wherein the active particles are
dispersed directly into the solution or: by using a dispersing
agent, or through the use of a removable encapsulant.
19. The method of 18 wherein, the active particles are dispersed
using a dispersing agent and further comprising, substantially
decreasing the agglomeration of active particles; and substantially
decreasing the number of active particles that fall out of the
solution.
20. The method of claim 14, wherein, physically incorporating the
active particles into the meta-aramid and/or para-aramid fiber
material occurs during the spinning of the solution and comprises
using dispersion forces or van der Waals forces to hold the active
particles and the meta-aramid and/or para-aramid fiber material
together.
Description
PRIORITY
[0001] This application claims priority to U.S. Provisional
Application No. 62/138,325, filed Mar. 25, 2015 and entitled
"Enhanced Meta-Aramid and Para-Aramid Fibers", which is
incorporated herein by reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to textile fibers. In
particular, but not by way of limitation, the present disclosure
relates to articles and methods for incorporating active particles
into meta-aramid and para-aramid fibers for improving the physical
characteristics of flame-resistant textiles.
BACKGROUND OF THE DISCLOSURE
[0003] Meta-aramid and para-aramid fibers are used in protective
textiles to protect objects and/or humans from excessive heat
exposure and burning caused by open flames. These fibers are
adapted to self-extinguish when they are exposed to a flash fire or
heat event. Various industry-standard test methods are used to
determine the heat resistance, flame resistance, and
self-extinguishing characteristics of such protective textiles.
Examples of common tests include the methods found in ASTM D6413,
ASTM F2700, and ASTM 2703, as well as the PyroMan.TM. test method,
developed by Ansell Protective Solutions AB, Johan Kocksgatan 10,
SE-231 81 Trelleborg, Sweden. The benefits of protection that
meta-aramids and para-aramids provide allow meta-aramids and
para-aramid fibers to be used in a wide range of applications where
flame resistance is required.
[0004] Wearing garments comprising meta-aramid and para-aramid
fibers provide the benefits of protecting the wearer from flame
exposure, but these benefits come at a cost of human comfort, since
moisture is unable to move through meta-aramid and para-aramid
fiber material. Similarly, meta-aramid and para-aramid materials
used to protect industrial components have the benefit of
protecting the parts from flame exposure, but moisture build-up
between the textile and the industrial component can cause other
problems. The movement of water vapor or liquid water is important
in either extending the comfort range for a human or to keep an
industrial part at an optimum moisture level.
SUMMARY OF INVENTION
[0005] These materials have a need to have improved moisture
function to extend the usage capability. It is desirable to improve
on the functionality of these products against a flame and other
thermal events. One embodiment of an invention providing these
improvements comprises a textile comprising a plurality of
synthetic fibers. In such a textile, the plurality of synthetic
fibers comprise a plurality of meta-aramid and/or para-aramid
fibers. A plurality of active particles are physically embedded in
the plurality of synthetic fibers, with the plurality of active
particles comprising a higher heat stability temperature than the
plurality of synthetic fibers.
[0006] Another embodiment of the invention comprises a
fire-resistant garment. One such fire-resistant garment comprises a
plurality of synthetic fibers and a plurality of active particles
physically embedded in the plurality of synthetic fibers. The
plurality of synthetic fibers comprises a plurality of meta-aramid
and/or para-aramid fibers and the plurality of active particles are
physically embedded in the plurality of synthetic fibers.
Furthermore, the plurality of active particles comprises a higher
heat stability temperature than the plurality of synthetic
fibers.
[0007] Yet another embodiment of the invention comprises a method
of creating a composite polymer textile. One such method comprises
creating a solution by dissolving meta-aramid and/or para-aramid
polymers into a solvent and dispersing active particles into the
solution. The solution is then spun using a spinneret, polymerizing
or precipitating the solution into a meta-aramid and/or para-aramid
fiber material and physically incorporating the active particles
into the meta-aramid and/or para-aramid fiber material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Various objects and advantages and a more complete
understanding of the present invention are apparent and more
readily appreciated by reference to the following Detailed
Description and to the appended claims when taken in conjunction
with the accompanying Drawings wherein:
[0009] FIG. 1 depicts a basic chemical structure of a para-aramid
and a meta-aramid according to one embodiment of the invention;
[0010] FIG. 2 depicts a microscopic image of zeolite according to
one embodiment of the invention;
[0011] FIG. 3 depicts a microscopic image of activated carbon
according to one embodiment of the invention;
[0012] FIG. 4 depicts garments according to one embodiment of the
invention;
[0013] FIG. 5 depicts a graphical representation of the moisture
management properties of a section of meta-aramid and/or
para-aramid textile without active particles and a section of
meta-aramid and/or para-aramid textile with active particles,
according to one embodiment of the invention;
[0014] FIG. 6 depicts two microscopic views of active particles as
they would be physically incorporated with meta-aramid or
para-aramid fibers, according to one embodiment of the invention;
and
[0015] FIG. 7 depicts a method of creating a composite polymer
textile according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0016] The term "or" as used in this specification and the appended
claims is meant to be an exclusive identification between two
terms, meaning "either". Therefore, when the "or" term is used with
reference to items A and B, for example, as in "items A or B", the
phrase should be viewed as "either of item A and item B, not both
of item A and B." The term "and" as used in the appended claims and
the specification is mean to be inclusive. In using the item A and
B example above, the phrase "item A and item B" should be viewed as
"both of item A along with item B." If the term "and/or" is used in
the claims and specification, the term should be viewed as
inclusive and exclusive. Therefore, in the example above, the
phrase "A and/or B" should be viewed as "either `A or B` or `A and
B`".
[0017] References in the specification to "one embodiment", "an
embodiment", "a preferred embodiment", "an alternative embodiment",
"a variation", "one variation", and similar phrases mean that a
particular feature, structure, or characteristic described in
connection with at least one embodiment of the invention. The
appearances of phrases like "in one embodiment", "in an
embodiment", or "in a variation" and similar phrases in various
places in the specification are not necessarily all meant to refer
to the same embodiment or variation and may refer to multiple
embodiments or variations. Similarly, the word "exemplary" is used
herein to mean "serving as an example, instance, or illustration."
Any use of the term "exemplary" herein is not necessarily to be
construed as preferred or advantageous over other embodiments.
[0018] An aramid fiber comprises a manufactured fiber in which the
fiber-forming substance is a long-chain synthetic polyamide where
at least 85% of the amide linkages (CO--NH--) in the polyamide are
attached directly to two aromatic rings. Meta-aramid and
para-aramid fibers differ slightly in their chemical composition as
compared to purely aramid fibers. Specifically, the position on the
aromatic rings to which the meta-aramid and para-aramid fibers bond
differs as compared to purely aramid fibers. FIG. 1 displays the
difference in chemical structure and molecular diagrams between a
para-aramid 100 and a meta-aramid 150 polymer, respectively.
Meta-aramid and para-aramid fibers also differ slightly with regard
to tensile, strength, and other properties.
[0019] Fibers comprising the meta-aramid 150 and para-aramid 100
structure seen in FIG. 1 comprise commercially-available textiles
such as, but not limited to, the materials marketed and sold under
the Kevlar.RTM. and Nomex.RTM. brands from E. I. du Pont de Nemours
and Company, 1007 Market Street Wilmington Del. 19898, as well as
the material marketed and sold under the Twaron.RTM. trademark from
Teijin Aramid B.V. Limited Liability Company, Velperweg 76, Arnhem,
Netherlands 6824 BM. These textiles, among others, are used in many
environments in which individuals, such as such as military
personnel, first responders, and factory workers, require
specialized flame-resistant apparel. However, a main feature of
these materials is also a drawback to their use. Specifically, the
highly impermeable nature of these materials to fire also leads to
the materials being highly impermeable to water and therefore have
little to no water adsorption or absorption properties. As such,
when these materials are worn, the heat causing a person to sweat
creates humidity between the user and the material, making the air
around the body highly uncomfortable within a very short period of
time.
[0020] As stated, meta-aramid and para-aramid fibers are also
useful in protecting structures and objects from heat and flame. In
industrial settings, pipes, tanks, pumps, and other structures and
equipment can be protected from damage with hoses or wraps
comprised of meta-aramid or para-aramid fibers surrounding the
equipment/structures. However, many pieces of industrial equipment
or structures also create condensation during operation and this
water buildup between the flame-resistant material and the
equipment can introduce additional problems. Meta-aramid and
para-aramid textiles are also further used in building materials as
a substitute for asbestos and/or other construction materials in
walls and ceilings. Building materials that include meta-aramid and
para-aramid textiles can cause humidity buildup within buildings.
In nearly every application of meta-aramid and para-aramid
materials, in order to alleviate the effects of humidity buildup,
some kind of ventilation is usually implemented. However, depending
on how various methods of ventilation are implemented, the
ventilation may compromise the effectiveness of the
flame-resistance system.
[0021] In order to alleviate this compromised effect of
ventilation, yet still provide decreased humidity in meta-aramid
and para-aramid materials, an embodiment of the invention comprises
a textile in which active particles are integrated into meta-aramid
and para-aramid fibers. One type of textile may comprise a woven
material, a non-woven material, or a performance-enhanced material.
The term "active particle" may be defined as a material with a
specific set of physical properties that interact with the
environment to achieve particular performance characteristics. One
type of active particle textile may comprise a polymer composite
comprising meta-aramid and/or para-aramid fibers and one or more
active particles. For ease of reference, textiles in accordance
with embodiments of the present disclosure comprising active
particles and either meta-aramid or para-aramid fibers may be
referred to as "composite textiles" or "composite polymer
textiles."
[0022] The active particles in composite textiles achieve two
desired performance characteristics: First, the active particles
may provide moisture management characteristics in the form of a
decreased or a substantial elimination of humidity and liquid
between the skin of the textile wearer and the textile; Second, the
particles may enhance the flame-resistant performance (i.e.,
increased resistance to burning when in contact or near a direct
flame) of the textile, beyond the existing characteristics if the
textile contains only meta-aramid and para-aramid fibers. For
example, to meet the requirements of ASTM D6413, the material must
not melt or drip, have less than 2 seconds of afterglow and after
flame, and less than 4 inches of char length. In order to achieve
these characteristics, the active particles themselves have
particular properties.
[0023] Providing desired moisture management properties to a
textile may be obtained through adding to the textile active
particles that 1) absorb infrared light in the 8 to 12 micron
wavelength region, 2) have the ability to adsorb and desorb (i.e.,
eject or emit) water at temperatures between 10 and 40.degree. C.,
and 3) have a surface area greater than 10 m.sup.2/g. Water is
absorbed by the active particles when the person begins to perspire
while wearing the garment. The active particles desorb the adsorbed
liquid or vapor when infrared light is absorbed by the active
particle, comprising enough energy to cause the water to desorb
from the particle. It is contemplated that the infrared light may
be emitted by the person wearing the garment. In one embodiment,
the amount of active particles in the textile may comprise from
about 0.01% to about 3% by weight. However, the active particle
loading level may be determined based on the strength of the fiber.
In some embodiments, increased active particle loading may occur
with increased tensile strength. The amount of water that is
absorbed and desorbed from the active particles may comprise an
evaporation rate. One or more of these particular properties may be
collectively referred to throughout the disclosure as the "moisture
management properties." The specific moisture management properties
described herein provide certain advantages which result in the
desired characteristics of the composite textile. For example, one
advantage that the capturing of infrared energy in the 8 to 12
micron wavelength region provides is an increase of the evaporation
rate of water as compared to its normal evaporation rate. For
example, woven fabric comprising Nomex.RTM. material without active
particles comprises an AATCC 200 drying rate of about 0.73 ml/h and
the same Nomex.RTM. fabric material with active particles comprises
a drying rate of about 3.5 ml/h. Such woven fabric may comprise of
15% polyethylene terephthalate (PET) doped with 1% active particles
blended with 85% Nomex.RTM. fibers. Additionally, the ability to
adsorb and desorb water while wearing the garment ensures that
moisture can pass through the composite textile at body temperature
and at normal ambient environmental temperatures. The surface area
property of greater than 10 m.sup.2/g generally indicates that a
particle has high porosity. High porosity can be advantageous in
active particles of the present disclosure because the large
surface area created by pores allows a relatively large amount of
water to be adsorbed to the surface of a particle in comparison to
its overall size, thereby creating a flow of perspiration from the
wear of the garment to the ambient environment, as described
above.
[0024] In order to enhance the flame-resistant characteristics of
the textile, the active particles may have a heat (thermal)
stability of greater than 300.degree. C. and a specific heat of
less than 1.3 J/gK at 293K. Many existing meta-aramid and
para-aramid fibers have a heat stability (otherwise known as a
thermal degradation temperature) of between 200 and 260.degree. C.
Incorporating active particles with a higher heat stability
temperature than the meta-aramid and para-aramid fibers is
advantageous because it is likely that the composite textile will
be exposed to temperatures of at least 200 to 260.degree. C. In
order to preserve the moisture management functionality of the
active particles, they should not degrade (e.g., decomposition and
volatilization) at temperatures that the meta-aramid and
para-aramid fibers are designed to be exposed to. Further, adding
the active particles as described in the present disclosure may
increase the overall heat stability of the textile to a higher
temperature threshold than existing meta-aramid and para-aramid
fibers. Several types of active particles can be utilized in
embodiments of the present disclosure, including zeolite and
activated carbon. In many embodiments, active particles may be
minerals that may absorb and desorb water with human infrared
energy. Any type of active particle having one or more of the
properties listed herein may be used without departing from the
scope of the present disclosure.
[0025] FIG. 2 depicts a microscopic image, as seen through a
scanning electron micrograph, of zeolite 275, an active particle
that may be integrated with meta-aramid or para-aramid fibers
according to aspects of the present disclosure. FIG. 3 also depicts
a close view, as seen through a scanning electron micrograph, of
activated carbon 325, another activated particle that may be
integrated with meta-aramid or para-aramid fibers according to
aspects of the present disclosure.
[0026] As seen in FIGS. 2 and 3, activated carbon 325 and zeolite
275 typically comprise a rough surface with many pores, which
result in a single particle having a large surface area. As
discussed previously, the large surface-area-to-size ratio allows
for activated particles to adsorb relatively large amounts of a
particular substance, such as water. In certain embodiments,
activated carbon may be in the form of activated charcoal.
[0027] FIG. 4 shows examples of articles of clothing and garments
that may be manufactured using the textiles and methods of the
present disclosure. Protective suits 400 and 401 may be used by
individuals who are regularly exposed to flames, such as
firefighters. Such suits may be used in combination with protective
head and neck coverings, such as head and neck covering 402. For
example, the protective suits 400, 401 may be won over head and
neck covering to limit skin exposure to flame. Often, meta-aramid
and para-aramid garments are worn in such a manner that no skin is
exposed, because the hazards faced by individuals wearing them
include sustained exposure to extreme heat or fire. For these
garments, ventilation in the form of openings in the fabric is
undesirable because the heat or fire could burn the wearer of the
garment through the openings.
[0028] FIG. 4 also shows a protective work shirt 403 that may be
worn by individuals who may only be exposed to a infrequent or
brief flame. These garments may be worn more loosely, and with more
openings (such as button holes) than the full fire-protective
described above. A protective work shirt 403 may comprise certain
meta-aramid and para-aramid fibers blended with more traditional
porous fabrics, such as cotton or polyester, in order to achieve an
increased level of comfort and breathability. However, these
traditional porous fabrics, when blended, may decrease the
flame-resistant properties of the meta-aramid and para-aramid
textile, because the porous fabrics let air and water through more
easily than the meta-aramid and para-aramid fibers and are also not
as flame resistant as the meta-aramid and para-aramid fibers.
Incorporating traditional porous textile fibers into meta-aramid
and para-aramid fibers typically decreases the flame resistance of
the resulting blended textile as compared to a pure meta-aramid or
para-aramid textile. In fact, adding too much of a traditional
porous fabric can cause a meta-aramid or para-aramid blend to lose
its self-extinguishing capability. In one embodiment, preferably
less than 25%, more preferably less than 20%, and most preferably
about 15% of the fiber in a porous/PET (or nylon) fiber and active
particle embodiment, by weight, may comprise fibers doped with
active particles. In contrast, composite textiles of the present
disclosure can allow breathability and moisture management without
substantially decreasing the flame resistance of the meta-aramid
and para-aramid fibers. As a result, composite textiles of the
present disclosure can be used advantageously in garments where
ventilation openings are impractical and potentially dangerous,
such as protective suits 400 and 401 and head coverings 402,
providing breathability even in high fire-exposure environments.
Additionally, composite textiles of the present disclosure may be
used in combination with, or in place of blended meta-aramid or
para-aramid garments, to provide increased flame resistance in more
comfortable clothing such as the protective work shirt 403.
[0029] FIG. 5 is a graphical representation depicting the
evaporation operation of a section of meta-aramid or para-aramid
textile 501 without active particles and a section of meta-aramid
or para-aramid textile 503 with active particles. As shown,
moisture and humidity 502 on a first side 510 of the textile 501 is
substantially blocked from escaping through to a second side 520 of
the textile 501. FIG. 5 also shows a composite textile 503
comprising meta-aramid or para-aramid fibers with active particles
integrated according to embodiments of the disclosure. As shown,
moisture and humidity 504 can move from the first side 510 of the
composite textile 503 to the second side 520. It is contemplated
that the first side 510 and second side 520 of the textile 501, 503
seen in FIG. 5 may also refer to a first side and second side of
the garments 400, 401, 402, and 403 seen in FIG. 4. In one
embodiment, the first side of the FIG. 4 garments 400, 401, 402,
and 403 may comprise a garment side nearest a person's body and a
second side of the garments 400, 401, 402, and 403 may comprise a
garment side nearest the ambient environment. Active particles may
be distributed uniformly or non-uniformly between the meta-aramid
or para-aramid fibers and throughout particular sections of the
textile to provide a desired number of active particles per sweat
pore located in that area.
[0030] Another aspect of the present disclosure provides a method
by which active particles and meta-aramid or para-aramid fibers may
be formed into a composite polymer textile. One method of
manufacturing meta-aramid and para-aramid fibers is wet-spinning.
Wet-spinning comprises a process in which a polymer/monomer is
dissolved into a solvent, and the solution is spun using a
spinneret, which precipitates or polymerizes the solution into a
relatively flat fiber material. The material is eventually quenched
into its solid form.
[0031] The method of the present disclosure may comprise dissolving
polymers of meta-aramid or para-aramid into a solvent. Solutions of
such dissolved polymers may be used in the process of wet-spinning
to manufacture meta-aramid and para-aramid fibers, rather than
heat-based extrusion methods of manufacturing, because once a
meta-aramid or para-aramid polymer is formed, it does not melt into
a liquid. One example of a solvent that may be used with the
presently disclosed method includes sulfuric acid. Those skilled in
the art can appreciate that solvents require particular
characteristics in order to allow the polymer to dissolve into a
solvent during the wet spinning process. Furthermore, an aspect of
the present disclosure is that the active particles are insoluble
and physically unaffected (not damaged) by the solvent. Therefore,
in addition to the physical properties of active particles listed
throughout the present disclosure, in some embodiments, the active
particles may also have the additional property of being insoluble
in certain known solvents. Alternatively, or additionally, in
various embodiments of the method, a particular solvent may be
chosen because it does not adversely impact the physical properties
of a desired active particle.
[0032] One method may further comprise dispersing active particles
into the solution. This dispersal may occur before or while the
solution is being spun through a spinneret. The particles can be
directly dispersed into the solution. Alternatively, the active
particles may be dispersed using a dispersing agent. One type of
dispersing agent may comprise Carbowet.RTM. from Air Products and
Chemicals, Inc. 7201 Hamilton Blvd. Allentown Pa. 18195. Advantages
to using a dispersing agent may be to achieve a higher level of
uniformity of particle distribution, prevent particles from
agglomerating, and prevent the particles from falling out of the
dispersion. Falling out of a dispersion comprises a particle
settling to the bottom of solution volume, preventing proper mixing
of the solution. As another alternative, the active particles may
be dispersed using a removable protective layer, such as an
encapsulant, as described in U.S. Pat. No. 7,247,374, which is
hereby incorporated by reference in its entirety. For example, when
an active particle is coated with a protective layer, the
protective layer may comprise a dispersing agent. Upon removal of
the encapsulant from the active particle, or before, the
encapsulant acts as a dispersing agent.
[0033] Upon dispersing the active particles in the solvent and then
subsequently wet-spinning the solution, active particles may become
physically incorporated and/or enmeshed with the meta-aramid or
para-aramid fibers. Though the active particles may not form
chemical bonds with the fibers, the two become physically
intertwined. In the art, the dispersion of insoluble particles into
a wet-spinning solution has not been pursued due to the knowledge
that (i) active particles would not form chemical bonds with the
tightly-aligned meta-aramid and para-aramid fibers and that (ii)
the active particles would have a negative impact on the formation
of the fibers. However, the method of the present disclosure
results in the physical entanglement of the particles with the
polymer fibers without negatively impacting the spinning process or
the formation of the fibers. In fact, dispersion forces or van der
Waals forces may also hold the active particles and meta-aramid or
para-aramid fibers together. Seen in FIG. 6 are two microscopic
views of active particles 601 as they would be physically
incorporated with meta-aramid or para-aramid fibers 602, as
described above. As shown, the active particles 601 are depicted as
spots of varying sizes physically integrated with the fibers
602.
[0034] FIG. 7 shows a flowchart which may be implemented to perform
a method 700 of the present disclosure. The method 700 starts at
704 and at step 701 the method may comprise dissolving a polymer
into a solvent, which results in a liquid solution. Such a polymer
may comprise a base monomer such as, but not limited to, polymers
of meta-aramids and/or para-aramids. Then, at step 702, the method
700 may comprise dispersing active particles into the liquid
solution. Next, at 703, the method 700 may further comprise
wet-spinning the solution into a composite textile of aramid fibers
and active particles. This may comprise polymerizing or
precipitating the solution into a meta-aramid and/or para-aramid
fiber material, along with physically incorporating the active
particles into the fiber material. The method 700 ends at 705.
[0035] The active particles that are dispersed into the solution
may be between 100 nm (0.1 microns) and 10 microns in size (e.g.
average diameter). It is contemplated that in some embodiments, a
given supply of active particles dispersed in a solution may be
non-uniform in size. The 100 nm to 10 micron size range of active
particles allows them to achieve certain properties. For example,
activated carbon particles in the size range of at least 100 nm to
may have a surface area greater than 10 m.sup.2/g, which allows for
optimal moisture management characteristics of the resulting
composite textile. Active particles of less than 10 microns in size
may be sufficiently large to provide the desired characteristics
while also being small enough to become entangled or enmeshed with
the meta-aramid and para-aramid fibers during the wet-spinning
manufacturing process.
[0036] The previous description of the disclosed embodiments is
provided to enable any person skilled in the art to make or use the
present invention. Various modifications to these embodiments will
be readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other embodiments
without departing from the spirit or scope of the invention. Thus,
the present invention is not intended to be limited to the
embodiments shown herein but is to be accorded the widest scope
consistent with the principles and novel features disclosed
herein.
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