U.S. patent application number 10/746964 was filed with the patent office on 2004-07-22 for fibers and fabrics with insulating, water-proofing, and flame-resistant properties.
Invention is credited to Coronado, Paul R., Hrubesh, Lawrence W., Poco, John F..
Application Number | 20040142168 10/746964 |
Document ID | / |
Family ID | 21701127 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040142168 |
Kind Code |
A1 |
Hrubesh, Lawrence W. ; et
al. |
July 22, 2004 |
Fibers and fabrics with insulating, water-proofing, and
flame-resistant properties
Abstract
Fibers, and fabrics produced from the fibers, are made water
repellent, fire-retardant and/or thermally insulating by filling
void spaces in the fibers and/or fabrics with a powdered material.
When the powder is sufficiently finely divided, it clings
tenaciously to the fabric's fibers and to itself, resisting the
tendency to be removed from the fabric.
Inventors: |
Hrubesh, Lawrence W.;
(Pleasanton, CA) ; Poco, John F.; (Livermore,
CA) ; Coronado, Paul R.; (Livermore, CA) |
Correspondence
Address: |
Eddie E. Scott
Assistant Laboratory Counsel
Lawrence Livermore National Laboratory
P.O. Box 808, L-703
Livermore
CA
94551
US
|
Family ID: |
21701127 |
Appl. No.: |
10/746964 |
Filed: |
December 24, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10746964 |
Dec 24, 2003 |
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10002513 |
Oct 25, 2001 |
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6723378 |
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Current U.S.
Class: |
428/375 ;
428/361; 428/378 |
Current CPC
Class: |
D06M 2200/30 20130101;
D04H 1/42 20130101; D06M 11/47 20130101; Y10T 428/2913 20150115;
D06M 23/10 20130101; D06M 11/45 20130101; D06M 23/08 20130101; Y10T
428/2915 20150115; Y10T 428/2938 20150115; Y10T 428/2907 20150115;
D04H 1/43916 20200501; Y10T 428/2973 20150115; D06M 11/46 20130101;
D06M 2200/40 20130101; D04H 1/413 20130101; D06M 11/73 20130101;
D06M 11/79 20130101; Y10T 428/2933 20150115 |
Class at
Publication: |
428/375 ;
428/378; 428/361 |
International
Class: |
D02G 003/00 |
Goverment Interests
[0002] The United States Government has rights in this invention
pursuant to Contract No. W-7405-ENG-48 between the United States
Department of Energy and the University of California for the
operation of Lawrence Livermore National Laboratory.
Claims
The invention claimed is:
1. A single fiber strand, comprising: a porous fiber strand having
voids, and at least some of said voids at least partially filled
with particles in the size range of 1-500 nm.
2. The single fiber strand of claim 1, wherein said particles are
at least partially composed of at least one of the following: a
porous material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or aggregates of
inorganic particle material, or combinations of said materials.
3. The single fiber strand of claim 1, wherein said particles are
at least partially composed of at least one of the following: an
insulating material, or a thermally insulating material, or a water
repellant material, or a hydrophobic material, or a hydrophobic,
nanoporous powdered material, or a hydrophobic silica aerogel, or
other metal oxide aerogels such as alumina, zirconia, tantala,
titania, etc., or laminates of aerogel powder, or a fire resistant
material, or combinations of said materials.
4. A single fiber made up of multiplicity of smaller single fiber
strands, comprising: a multiplicity of smaller single porous fiber
strands having voids, at least some of said voids at least
partially filled with particles in the size range of 1-500 nm, and
said multiplicity of smaller single porous fiber strands associated
with each other to form a single fiber.
5. The single fiber strand of claim 4, wherein said particles are
at least partially composed of at least one of the following: a
porous material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or aggregates of
inorganic particle material, or an insulating material, or a
thermally insulating material, or a water repellant material, or a
hydrophobic material, or a hydrophobic, nanoporous powdered
material, or a hydrophobic silica aerogel, or laminates of aerogel
powder, or a fire resistant material, or combinations of said
materials.
6. A single fiber made up of multiplicity of smaller single fiber
strands, comprising: a multiplicity of smaller single porous or
non-porous fiber strands having a void volume between said smaller
single porous or non-porous fiber strands, at least a portion of
said void volume at least partially filled with particles in the
size range of 1-500 nm, and said multiplicity of smaller single
porous or non-porous fiber strands associated with each other to
form a single fiber.
7. The single fiber made up of multiplicity of smaller single fiber
strands, claim 6, wherein said particles are at least partially
composed of at least one of the following: a porous material, or a
nanoporous material, or a nanoporous powdered material, or a solgel
derived material, or an aerogel-like material, or an aerogel, or an
inorganic material, or aggregates of inorganic particle material,
or an insulating material, or a thermally insulating material, or a
water repellant material, or a hydrophobic material, or a
hydrophobic, nanoporous powdered material, or a hydrophobic silica
aerogel, or other metal oxide aerogels such as alumina, zirconia,
tantala, titania, etc., or a fire resistant material, or
combinations of said materials.
8. A fabric, comprising: a multiplicity of fibers, said
multiplicity of fibers associated with each other to form said
fabric, said fibers containing a void volume located either in said
fibers or between said fibers or both in said fibers and between
said fibers, and at least a portion of said void volume at least
partially filled with particles in the size range of 1-500 nm.
9. The fabric of claim 8, wherein said particles are at least
partially composed of at least one of the following: a porous
material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or aggregates of
inorganic particle material, or an insulating material, or a
thermally insulating material, or a water repellant material, or a
hydrophobic material, or a hydrophobic, nanoporous powdered
material, or a hydrophobic silica aerogel, or other metal oxide
aerogels such as alumina, zirconia, tantala, titania, etc., or a
fire resistant material, or combinations of said materials.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a division of application Ser. No.
10/002,513 filed Oct. 25, 2001 entitled "Fibers and Fabrics With
Insulating, Water-Proofing, and Flame-Resistant Properties."
BACKGROUND OF THE INVENTION
[0003] 1. Field of Endeavor
[0004] The present invention relates to fibers and fabrics and more
particularly to fibers and fabrics with insulating, waterproofing,
and flame-resistant properties.
[0005] 2. State of Technology
[0006] U.S. Pat. No. 6,040,251 for garments of barrier webs by J.
Michael Caldwell, patented Mar. 21, 2000, incorporated herein by
reference, provides the following background information, "Barrier
fabrics are generally characterized by being impervious to
penetration by liquids. There is a class of barrier fabrics which,
additionally, are vapor permeable to provide what is termed
breathability. Barrier fabrics are especially useful in the medical
career apparel garments. The barrier fabrics in the prior art can
be generally classified as disposable and reuseable. Disposable
fabrics are typically constructed from nonwovens made from light
weight synthetic fibers or synthetic fibers blended with natural
fibers. Performance of disposable nonwoven fabrics in terms of
liquid repellency and flame retardancy are quite acceptable.
Reusable fabrics are normally woven and may be constructed from
cotton or cotton/polyester blends of a high thread count to provide
a physical barrier to prevent or reduce the spread of infectious
materials and vectors.
[0007] While reusable woven fabrics generally offer more comfort in
terms of drapeability, breathability, transmission of heat and
water vapor, stiffness, etc., and improved (reduced) cost per use,
they lack the liquid repellency the market has come to expect on
the basis of experience with the disposables, especially after
repeated launderings and/or steam (autoclave) sterilizations.
[0008] Woven reusable surgical barrier fabrics must meet or exceed
the current criteria for National Fire Protection Association
(NFPA-99) and the Association of Operating Room Nurses (AORN)
"Recommended Practices-Aseptic Barrier Material for Surgical Gowns
and Drapes" used in constructing operating room wearing apparel,
draping and gowning materials. To be effective, the fabric must be
resistant to blood and aqueous fluid (resist liquid penetration);
abrasion resistant to withstand continued reprocessing; lint free
to reduce the number of particles and to reduce the dissemination
of particles into the wound; drapeable; sufficiently porous to
eliminate heat buildup; and flame resistant.
[0009] Reusable fabrics should withstand multiple laundering and,
where necessary, sterilization (autoclaving) cycles; be
non-abrasive and free of toxic ingredients and non-fast dyes; be
resistant to tears and punctures; provide an effective barrier to
microbes, preferably be bacteriostatic in their own right; and the
reusable material should maintain its integrity over its expected
useful life.
[0010] None of the fabrics or the fabrics taught in the prior art
has the physical characteristics of (1) being substantially
resistant or impermeable to liquids, such as water, (2) being
permeable to gases, and (3) impermeable to microorganisms. In
addition, none of the fabrics taught in the prior art teach or
suggest fabrics that are capable of selectively removing or
retaining microorganisms or other particles or molecules from the
surrounding milieu.
[0011] In the prior art, it has been proposed to treat porous webs,
especially fabrics, with silicone resins and also with
fluorochemicals. Conventional treatments of webs fall into the
general categories of (i) surface coatings and (ii) saturations or
impregnations.
[0012] For example, U.S. Pat. Nos. 3,436,366; 3,639,155; 4,472,470;
4,500,584; and 4,666,765 disclose silicone coated fabrics. Silicone
coatings are known to exhibit relative inertness to extreme
temperatures of both heat and cold and to be relatively resistant
to ozone and ultraviolet light. Also, a silicone coating can
selectively exhibit strength enhancement, flame retardancy and/or
resistance to soiling. Fluorochemical treatment of webs is known to
impart properties, such as soil resistance, grease resistance, and
the like.
[0013] Prior art fluorochemical and silicone fabric treatment
evidently can protect only that side of the fabric upon which they
are disposed. Such treatments significantly alter the hand, or
tactile feel, of the treated side. Prior silicone fabric coatings
typically degrade the tactile finish, or hand, of the fabric and
give the coated fabric side a rubberized finish which is not
appealing for many fabric uses, particularly garments.
[0014] U.S. Pat. No. 4,454,191 describes a waterproof and
moisture-conducting fabric coated with a hydrophilic polymer. The
polymer is a compressed foam of an acrylic resin modified with
polyvinyl chloride or polyurethane and serves as a sort of
"sponge," soaking up excess moisture vapor. Other microporous
polymeric coatings have been used in prior art attempts to make a
garment breathable, yet waterproof.
[0015] Various polyorganosiloxane compositions are taught in the
prior art that can be used for making coatings that impart
water-repellency to fabrics. Typical of such teachings is the
process described in U.S. Pat. No. 4,370,365 which describes a
water repellent agent comprising, in addition to an
organohydrogenpolysiloxane, either one or a combination of linear
organopolysiloxanes containing alkene groups, and a resinous
organopolysiloxane containing tetrafunctional and monofunctional
siloxane units. The resultant mixture is catalyzed for curing and
dispersed into an aqueous emulsion. The fabric is dipped in the
emulsion and heated. The resultant product is said to have a good
"hand" and to possess waterproofness.
[0016] This type of treatment for rendering fabrics water repellent
without affecting their "feel" is common and well known in the art.
However, it has not been shown that polyorganosiloxanes have been
coated on fabrics in such a way that both high levels of resistance
to water by the fibers/filaments and high levels of permeability to
water vapor are achieved. As used herein, the term "high levels of
permeability to water vapor" has reference to a value of at least
about 500 gms/m.sup.2/day, as measured by ASTM E96-80B. Also, as
used herein, the term "high level of waterproofness" is defined by
selective testing methodologies discussed later in this
specification. These methodologies particularly deal with water
resistance of fabrics and their component fibers.
[0017] Porous webs have been further shown to be surface coated in,
for example, U.S. Pat. Nos. 4,478,895; 4,112,179; 4,297,265;
2,893,962; 4,504,549; 3,360,394; 4,293,611; 4,472,470; and
4,666,765. These surface coatings impart various characteristics to
the surface of a web, but do not substantially impregnate the web
fibers. Such coatings remain on the surface and do not provide a
film over the individual internal fibers and/or yarn bundles of the
web. In addition, such coatings on the web surface tend to wash
away quickly.
[0018] Prior art treatments of webs by saturation or impregnation
also suffer from limitations. Saturation, such as accomplished by
padbath immersion, or the like, is capable of producing variable
concentrations of a given saturant chemical.
[0019] To treat a flexible web, by heavy saturation or impregnation
with a polymer material, such as a silicone resin, the prior art
has suggested immersion of the flexible web, or fabric, in a
padbath, or the like, using a low viscosity liquid silicone resin
so that the low viscosity liquid can flow readily into, and be
adsorbed or absorbed therewithin. The silicone resin treated
product is typically a rubberized web, or fabric, that is very
heavily impregnated with silicone. Such a treated web is
substantially devoid of its original tactile and visual properties,
and instead has the characteristic rubbery properties of a cured
silicone polymer.
[0020] International Patent Application W00106054 A1 for
nanoparticle-based permanent treatment for textiles by Soane et al,
published Jan. 25, 2001 provides the following information, "an
agent or other payload entrapped, that is, surrounded by or
contained within a synthetic, polymer shell or matrix that is
reactive to fibers, yarns, fabrics, or webs, to give
textile-reactive beads or matrices. The beads or matrices are
micrometric or nanometric in size, and are herein collectively and
interchangeably referred to as "nanobeads" and "nanoparticles." The
nanobead/nanoparticle of the invention may comprise a polymeric
shell surrounding the payload or it may comprise a
three-dimensional polymeric network entrapping the payload, both of
which are referred to herein as a polymer shell." By
"textile-reactive" is meant that the payload bead will form a
chemical covalent bond with the fiber, yarn, fabric, textile,
finished goods (including apparel), or other web or substrate to be
treated. The polymer shell or polymer network of the payload
nanoparticle has a surface that includes functional groups for
binding or attachment to the fibers, filaments or structural
components or elements (referred to collectively herein and in the
appended claims as "fibers") of the textiles or other webs to be
treated, to provide permanent attachment of the payload to the
fibers. Alternatively, the surface of the nanobead includes
functional groups that can bind to a linker molecule that will in
turn bind or attach the bead to the fiber. In either case, these
functional groups are referred to herein as "textile-reactive
functional groups" or "fiber-reactive functional groups" or
"substrate-reactive functional groups." The terms "payload" and
"payload agent" as used herein refer collectively to any material
or agent that would be desirable for permanent attachment to or
treatment of a textile or other web. Alternatively, the payload
agent may be released from the cage of the payload nanobead in a
controlled and prolonged fashion. The chemical linkage on the
surface of the nanobead does not involve the molecules of the
payload. The payload agents are physically entrapped within the
nanoparticle, thus requiring no chemical modifications of the
agents themselves. The resulting encapsulated payload preparations
or nanoparticles have improved retention within and on the textile
or web fiber structure without changing the inherent character of
the payload agent. The architecture of the shell or matrix of the
nanobead can be formulated and fine-tuned to exhibit controlled
release of the entrapped payload, ranging from constant but
prolonged release (desirable for drugs, biologic or anti-biologic
agents, softeners, and fragrances, for example) to zero release
(desirable for dyes, metallic reflector colloids, and sunblock
agents, for example). In an encapsulated configuration, the beads
will desirably insulate the payload from the skin, preventing
potential allergic reactions. In addition, the nanoparticle can be
designed to respond to different environmental stimuli (such as
temperature, light change, pH, or moisture) to increase the rate of
release, color change, or temperature change at certain times or in
certain selected spots or locations on the textile or finished
good. This invention is further directed to the fibers, yarns,
fabrics (which may be woven, knitted, stitch-bonded or nonwoven),
other textiles, or finished goods (encompassed collectively herein
under the terms "textiles" or "webs") treated with the
textile-reactive nanoparticles. Such textiles and webs exhibit a
greatly improved retention or durability of the payload agent and
its activity, even after multiple washings. Methods are provided
for synthesizing a textile-reactive payload-containing
nanoparticle. The preparations of the invention may be formed via
one of several methods of encapsulation, such as interfacial
polymerization, microemulsion polymerization, precipitation
polymerization, and diffusion. Multi-component mixture preparation
followed by atom ization/spraying into a drying chamber is yet
another processing scheme. Reactive functional groups on the
polymer shell provide a means for attaching the payload
nanoparticles to textiles."
[0021] U.S. Pat. No. 2,673,823 teaches impregnating a polymer into
the interstices of a fabric and thus fully filling the interstices.
This patent provides no control of the saturation of the fabric. It
teaches full saturation of the interstices of the fabric.
[0022] The prior art application of liquid or paste compositions to
textiles for purposes of saturation and/or impregnation is
typically accomplished by an immersion process. Particularly for
flexible webs, including fabric, an immersion application of a
liquid or paste composition to the web is achieved, for example, by
the so-called padding process wherein a fabric material is passed
first through a bath and subsequently through squeeze rollers in
the process sometimes called single-dip, single-nip padding.
Alternatively, for example, the fabric can be passed between
squeeze rollers, the bottom one of which carries the liquid or
paste composition in a process sometimes called double-dip or
double-nip padding.
[0023] Prior art treatment of webs that force a composition into
the spaces of the web while maintaining some breathability have
relied on using low viscosity compositions or solvents to aid in
the flow of the composition. U.S. Pat. No. 3,594,213 describes a
process for impregnating or coating fabrics with liquefied
compositions to create a breathable fabric. This patent imparts no
energy into the composition to liquefy it while forcing it into the
spaces of the web. The composition is substantially liquefied
before placement onto and into the web. U.S. Pat. No. 4,588,614
teaches a method for incorporating an active agent into a porous
substrate.
[0024] This patent utilizes a solvent to aid in the incorporation
of the active agent into the web. Prior art apparatus for the
coating of webs, including fabrics, generally deposits a coating
onto the fabric at a desired thickness. Coating at a predetermined
thickness can be achieved by deposition of coating material or by
the scraping of a coating upon the fabric by knives. Flexible webs
are generally urged between oppositely disposed surfaces, one of
which would be a doctoring blade or drag knife. The blade or knife
smooth the coating and maintain the thickness of the coating to a
desired thickness. For example, it is possible to apply a
relatively thick silicone liquid elastomer coating to a rough web,
typically of fiberglass, in order to make architectural fabric as
is taught in U.S. Pat. No. 4,666,765. In this example, the drag
knives are set to a thickness of about 2 to 10 mils thicker than
the web thickness. This setting, depending on the coating speed,
can yield a base coat thickness of approximately 3 to 12 mils
thicker than the web thickness.
[0025] Various types of coatings, and various coating thicknesses,
are possible. However, a general principle of coating machinery is
that the coating material is swept, or dragged, along the surface
of the fabric. No special attention is normally given to any
pressured forcing of the coating into the fabric, therein making
the coating also serve as an impregnant. Of course, some coating
will be urged into surface regions of the fabric by the coating
process. Generally, however, application of high transversely
exerted (against a fiber or web surface) forces at the location of
the coating deposition and/or smoothing is not desired in the prior
art processes because it is the goal of the prior art coating
processes to leave a definite thickness of coating material upon a
surface of the fabric, and not to scrape the fabric clean of
surface-located coating material.
[0026] One prior art silicone resin composition is taught by U.S.
Pat. Nos. 4,472,470 and 4,500,584, and includes a vinyl terminated
polysiloxane, typically one having a viscosity of up to about
2,000,000 centipoises at 25.degree. C., and a resinous
organosiloxane polymer. The composition further includes a platinum
catalyst, and an organohydrogenpolysiloxane crosslinking agent, and
is typically liquid. Such composition is curable at temperatures
ranging from room temperature to 100 C or higher depending upon
such variables as the amount of platinum catalyst present in the
composition, and the time and the temperature allowed for
curing.
[0027] Such compositions may additionally include fillers,
including finely divided inorganic fillers. Silicone resin
compositions that are free of any fillers are generally transparent
or translucent, whereas silicone resin compositions containing
fillers are translucent or opaque depending upon the particular
filler employed. Cured silicone resin compositions are variously
more resinous, or hard, dependent upon such variables as the ratio
of resinous copolymer to vinyl terminated polysiloxane, the
viscosity of the polysiloxane, and the like.
[0028] Curing (including polymerization and controlled
crosslinking) can encompass the same reactions. However, in the
fabric finishing arts, such terms can be used to identify different
phenomena. Thus, controllable and controlled curing, which is
taught by the prior art, may not be the same as control of
crosslinking. In the fabric finishing arts, curing is a process by
which resins or plastics are set in or on textile materials,
usually by heating. Controlled crosslinking may be considered to be
a separate chemical reaction from curing in the fabric finishing
arts. Controlled crosslinking can occur between substances that are
already cured. Controlled crosslinking can stabilize fibers, such
as cellulosic fibers through chemical reaction with certain
compounds applied thereto. Controlled crosslinking can improve
mechanical factors such as wrinkle performance and can
significantly improve and control the hand and drape of the web.
Polymerization can refer to polymer formation or polymer
growth.
[0029] What is needed in the industry is a barrier fabric that is
impermeable to liquids, is permeable to gases, and is impermeable
to microorganisms. In addition, what is needed are methods and
processes for producing fabrics with predetermined pore sizes that
allow the manufacturer to produce a fabric with a desired pore
size."
[0030] European Patent No. EP0846802 for a method of filling a
hollow fiber with gel by Hajime Izawa and Togi Suzuki of Teijin
Limited-Osaka Research Center, published Jun. 10, 1998,
incorporated herein by reference, provides the following
description, "This invention provides a method for filling a hollow
portion of a hollow fiber with a gel without requiring special
equipment such as pressure resistant facilities and enabling an
industrial mass production, which comprises immersing said hollow
fiber on the surface of which pores are diffusely distributed to
communicate to said hollow portion in a gelable liquid, leaving
said hollow fiber at room temperature so that said gelable liquid
may be absorbed through said pores into the hollow portion, and
finally causing thus absorbed gelable liquid gelled."
[0031] U.S. Pat. No. 5,830,548 for articles of manufacture and
methods for manufacturing laminate structures including
inorganically filled sheets by Per Just Andersen and Simon K.
Hodson, patented Nov. 3, 1998, incorporated herein by reference,
provides the following description, "Compositions and methods for
manufacturing composite laminate structures incorporating sheets
having a moldable matrix are disclosed. Suitable compositions are
prepared by mixing together a water dispersable organic binder,
water, and appropriate additives (such as aggregates and fibers)
which impart predetermined properties so that a sheet formed
therefrom has the desired performance criteria. The compositions
are formed into sheets by first extruding them into a sheet and
then calendaring the sheet using a set of rollers. The calendered
sheets are dried in an accelerated manner to form a substantially
hardened sheet. The drying process is performed by heated rollers
and/or a drying chamber. The inorganically filled sheets so formed
may have properties substantially similar to sheets made from
presently used materials like paper, cardboard, polystyrene, or
plastic. Such sheets can be rolled, pressed, scored, perforated,
folded, and glued before or after being incorporated into composite
laminate structures. Such composite laminate structures have
especial utility in the mass production of containers, particularly
food and beverage containers."
[0032] U.S. Pat. No. 6,129,978 for Porous webs having a polymer
composition controllably placed therein by J. Michael Caldwell,
patented Oct. 10, 2000, incorporated herein by reference, provides
the following description, "The present invention relates to a
porous web comprising a plurality of structural elements with
interstitial spaces therebetween, wherein at least some of the
structural elements of the top and bottom surfaces of the web are
encapsulated by a cured, shear thinned polymer composition and most
of the interstitial spaces are open. The invention also relates to
a porous web having a substantially continuous region of a cured,
shear thinned polymer composition extending through the web so that
the polymer composition fills the interstitial spaces and adheres
adjacent structural elements of the web in the region. In the areas
of the web above and below the filled region, at least some of the
structural elements are encapsulated and most of the interstitial
spaces are open."
[0033] U.S. Pat. No. 6,180,037 for methods for the manufacture of
sheets having a highly inorganically filled organic polymer matrix
by Just Andersen and Simon K. Hodson, patented Jan. 30, 2001,
provides the following description, "Compositions and methods for
manufacturing sheets having a highly inorganically filled matrix.
Suitable inorganically filled mixtures are prepared by mixing
together an organic polymer binder, water, one or more inorganic
aggregate materials, fibers, and optional admixtures in the correct
proportions in order to form a sheet which has the desired
performance criteria. The inorganically filled mixtures are formed
into sheets by first extruding the mixtures and the passing the
extruded materials between a set of rollers. The rolled sheets are
dried in an accelerated manner to form a substantially hardened
sheet, such as by heated rollers and/or a drying chamber. The
inorganically filled sheets may have properties substantially
similar to sheets presently made from traditional materials like
paper, cardboard, polystyrene, plastic, or metal. Such sheets can
be rolled, pressed, scored, perforated, folded, and glued. They
have especial utility in the mass production of containers,
particularly food and beverage containers."
SUMMARY OF THE INVENTION
[0034] Features and advantages of the present invention will become
apparent from the following description. Applicants are providing
this description, which includes drawings and examples of specific
embodiments, to give a broad representation of the invention.
Various changes and modifications within the spirit and scope of
the invention will become apparent to those skilled in the art from
this description and by practice of the invention. The scope of the
invention is not intended to be limited to the particular forms
disclosed and the invention covers all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention as defined by the claims.
[0035] The present invention provides fibers and fabrics that have
desirable properties. Embodiments of the invention provide fibers
and fabrics that have insulating, waterproofing, and/or fire
resistant properties. In various embodiment of the invention,
fibers, and fabrics produced from the fibers, are made water
repellent, fire-retardant and/or thermally insulating by filling
the void spaces in the fibers and/or fabrics with a powdered
material. When the powder is sufficiently finely divided, it clings
tenaciously to the fabric's fibers and to itself, resisting the
tendency to be removed from the fabric. The present invention has
many uses including uses for military clothing, blankets, tents,
raingear, fire/flame protection clothing, blankets, tents,
raingear, fire/flame protection, etc.
[0036] In one embodiment of the invention a single fiber strand
includes a porous fiber strand having voids. At least some of the
voids are at least partially filled with particles in the size
range of 1-500 nm. In another embodiment a single fiber is made up
of multiplicity of smaller single fiber strands. The smaller single
porous fiber strands have voids and at least some of the voids are
at least partially filled with particles in the size range of 1-500
nm. In another embodiment of the invention a single fiber is made
up of multiplicity of smaller single fiber strands. The
multiplicity of smaller single porous or non-porous fiber strands
have voids between the smaller single porous or non-porous fiber
strands. At least a portion of the voids are at least partially
filled with particles in the size range of 1-500 nm.
[0037] In various embodiments of the invention the particles are at
least partially composed of at least one of the following: a porous
material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or aggregates of
inorganic particle material, or combinations of the materials. In
other embodiments of the invention the particles are at least
partially composed of at least one of the following: an insulating
material, or a thermally insulating material, or a water repellant
material, or a hydrophobic material, or a hydrophobic, nanoporous
powdered material, or a hydrophobic silica aerogel, or a fire
resistant material, or combinations of the materials. The present
invention is not be limited to silica aerogels, other metal oxide
aerogels, e.g., alumina, zirconia, tantala, titania, etc., and
carbon aerogels are included. The present invention also includes
laminates of aerogel powder or powder impregnated fabrics, with
other fabrics--where the aerogel layer provides the physical
properties of repellancy, fire resistence, and thermal resistence
(as well as providing other barrier possibilities by
absorption.)
[0038] Another embodiment of the present invention provides a
method of producing a fiber. A porous fiber strand containing voids
is provided. The voids are filled with particles in the size range
of 1-500 nm. The particles are at least partially composed of at
least one of the following: a porous material, or a nanoporous
material, or a nanoporous powdered material, or a solgel derived
material, or an aerogel-like material, or an aerogel, or an
inorganic material, or aggregates of inorganic particle material,
or an insulating material, or a thermally insulating material, or a
water repellant material, or a hydrophobic material, or a
hydrophobic, nanoporous powdered material, or a hydrophobic silica
aerogel, or a fire resistant material, or combinations of the
materials. The present invention is not be limited to silica
aerogels, other metal oxide aerogels, e.g., alumina, zirconia,
tantala, titania, etc., and carbon aerogels are included. The
method includes the step of: filling the voids with a solution
which precipitates particles as it dries, or filling the voids with
a solution containing a colloidal suspension of particles which
remain when the liquid dries, or filling the voids with a dry
powder by passing the fibers through the powder in a manner in
which the particles attach to the fibers, or filling the voids with
a dry powder by passing the powder over the fibers in a manner in
which the particles attach to the fibers, or filling the voids with
a dry powder by forcing dry powder to enter the space using
rollers, or filling the voids with a dry powder by forcing dry
powder to enter the space using a press, or combinations of the
steps.
[0039] Another embodiment of the present invention provides a
method of producing a fiber made up of multiplicity of smaller
single fiber strands. Voids are located between the smaller single
fiber strands. The voids are filled with particles in the size
range of 1-500 nm. In various embodiments the particles are at
least partially composed of at least one of the following: a porous
material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or aggregates of
inorganic particle material, or an insulating material, or a
thermally insulating material, or a water repellant material, or a
hydrophobic material, or a hydrophobic, nanoporous powdered
material, or a hydrophobic silica aerogel, or a fire resistant
material, or combinations of the materials. The present invention
is not be limited to silica aerogels, other metal oxide aerogels,
e.g., alumina, zirconia, tantala, titania, etc., and carbon
aerogels are included. The method includes the step of: filling the
voids with a solution which precipitates particles as it dries, or
filling the voids with a solution containing a colloidal suspension
of particles which remain when the liquid dries, or filling the
voids with a dry powder by passing the fibers through the powder in
a manner in which the particles attach to the fibers, or filling
the voids with a dry powder by passing the powder over the fibers
in a manner in which the particles attach to the fibers, or filling
the voids with a dry powder by forcing dry powder to enter the
space using rollers, or filling the voids with a dry powder by
forcing dry powder to enter the space using a press, or
combinations of the steps.
[0040] Another embodiment of the invention provides a method of
producing a fabric. A multiplicity of fibers is located in
association with each other to form the fabric. The fibers
containing a void volume located either in the fibers or between
the fibers or both in the fibers and between the fibers. At least a
portion of the void volume is filled with particles in the size
range of 1-500 nm. In various embodiments the particles are at
least partially composed of at least one of the following: a porous
material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or aggregates of
inorganic particle material, or an insulating material, or a
thermally insulating material, or a water repellant material, or a
hydrophobic material, or a hydrophobic, nanoporous powdered
material, or a hydrophobic silica aerogel, or a fire resistant
material, or combinations of the materials. The present invention
is not be limited to silica aerogels, other metal oxide aerogels,
e.g., alumina, zirconia, tantala, titania, etc., and carbon
aerogels are included. The method includes the step of: filling the
voids with a solution which precipitates particles as it dries, or
filling the voids with a solution containing a colloidal suspension
of particles which remain when the liquid dries, or filling the
voids with a dry powder by passing the fibers through the powder in
a manner in which the particles attach to the fibers, or filling
the voids with a dry powder by passing the powder over the fibers
in a manner in which the particles attach to the fibers, or filling
the voids with a dry powder by forcing dry powder to enter the
space using rollers, or filling the voids with a dry powder by
forcing dry powder to enter the space using a press, or
combinations of the steps.
[0041] The invention is susceptible to modifications and
alternative forms. Specific embodiments are shown by way of
example. It is to be understood that the invention is not limited
to the particular forms disclosed. The invention covers all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The accompanying drawings, which are incorporated into and
constitute a part of the specification, illustrate specific
embodiments of the invention and, together with the general
description of the invention given above, and the detailed
description of the specific embodiments, serve to explain the
principles of the invention.
[0043] FIG. 1 is a side view showing a schematic drawing of a
portion of a single fiber made up of strands of smaller fibers.
[0044] FIG. 2 is an end view of the single fiber show in FIG.
1.
[0045] FIG. 3 is a schematic drawing of a fabric made of woven
fibers with the space between the woven fibers filled with nanosize
particles (diameters in the size range from 1-500 nm.)
DETAILED DESCRIPTION OF THE INVENTION
[0046] Referring now to the drawings, to the following detailed
information, and to incorporated materials; a detailed description
of the invention, including specific embodiments, are described.
The description of the specific embodiments, together with the
general description of the invention, serve to explain the
principles of the invention.
[0047] The present invention provides fibers and fabrics that have
desirable properties. Embodiments of the invention provide fibers
and fabrics that have insulating, waterproofing, and fire resistant
properties. In various embodiment of the invention, fibers, and
fabrics produced from the fibers, are made water repellent,
fire-retardant and/or thermally insulating by filling the void
spaces in the fibers and/or fabrics with a powdered material. When
the powder is sufficiently finely divided, it clings tenaciously to
the fabric's fibers and to itself, resisting the tendency to be
removed from the fabric. Thus, this treatment offers substantial
long term improvement of the water repellant and thermal insulation
properties over the untreated fabric, while not adding much
additional weight.
[0048] Embodiments of the Invention Using a Fiber Made of Smaller
Single Fibers
[0049] In one embodiment of the present invention a method is
described of producing a fiber made up of multiplicity of smaller
single fiber strands. This embodiment includes the steps of
providing an assembly of single fiber strands. The assembly has a
void volume between the smaller single fiber strands. The void
volume is filled with particles in the size range of 1-500 nm.
Various embodiments of method of filling the void volume will be
described. The embodiments include filling the void volume with a
solution that precipitates particles as it dries. In another
embodiment the void volume is filled with a solution containing a
colloidal suspension of particles that remain when the liquid
dries. In another embodiment the void volume is filled with a dry
powder by passing the fibers through a powder in a manner in which
the particles attach to the fibers. In another embodiment the void
volume is filled with a dry powder by passing the powder over the
fibers in a manner in which the powder particles attach to the
fibers. In another embodiment the void volume is filled a dry
powder by forcing the dry powder to enter the space using rollers.
In another embodiment the void volume is filled by forcing dry
powder to enter the space using a press.
[0050] In one of the embodiments of producing a fiber made up of
multiplicity of smaller single fiber strands, the particles are at
least partially composed of a porous material. In one of the
embodiments of producing a fiber made up of multiplicity of smaller
single fiber strands, the particles are at least partially composed
of a nanoporous material. In one of the embodiments of producing a
fiber made up of multiplicity of smaller single fiber strands, the
particles are at least partially composed of a nanoporous powdered
material. In various other embodiments of the invention the
particles are at least partially, composed of a solgel derived
material, composed of an aerogel-like material, composed of an
aerogel, composed of an inorganic material, composed of aggregates
of inorganic particles, contain an insulating material, contain a
thermally insulating material, composed of an insulating material,
composed of a thermally insulating material, contain a water
repellant material, contain a hydrophobic material, contain a
hydrophobic, nanoporous powdered material, composed of a water
repellant material, composed of a hydrophobic material, composed of
a hydrophobic, nanoporous powdered material, composed of a
hydrophobic silica aerogel, contain a fire resistant material,
and/or composed of a fire resistant material. The present invention
is not be limited to silica aerogels, other metal oxide aerogels,
e.g., alumina, zirconia, tantala, titania, etc., and carbon
aerogels are included. The present invention also includes
laminates of aerogel powder or powder impregnated fabrics, with
other fabrics--where the aerogel layer provides the physical
properties of repellancy, fire resistence, and thermal resistence
(as well as providing other barrier possibilities by
absorption.)
[0051] Embodiments of the Invention Using a Porous Fiber
[0052] The smaller fiber strands described above may be porous or
non-porous. Embodiments of the invention utilizing porous fibers
include the steps of providing a porous fiber strand wherein the
porous fiber strand contains voids. The voids are filled with
particles in the size range of 1-100 nm. Various embodiments of
method of filling the voids will be described. In one embodiment
the voids are filled with a solution which precipitates particles
as it dries. In another embodiment the voids are filled with a
solution containing a colloidal suspension of particles which
remain when the liquid dries. Other embodiments include: filling
the voids with a dry powder by passing the fibers through the
powder in a manner in which the particles attach to the fibers,
filling the voids with a dry powder by passing the powder over the
fibers in a manner in which the particles attach to the fibers,
filling the voids with a dry powder by forcing dry powder to enter
the space using rollers, and/or filling the voids with a dry powder
by forcing dry powder to enter the space using a press. In various
embodiments the particles are at least partially composed of: a
porous material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an inorganic material, or an insulating
material, or a thermally insulating material, or aggregates of
inorganic particles, or combinations of the foregoing
materials.
[0053] In various embodiments the particles at least partially
contain: a water repellant material, or a hydrophobic material, or
a hydrophobic, nanoporous powdered material, or a water repellant
material, or a hydrophobic material, or a hydrophobic, nanoporous
powdered material, or a hydrophobic silica aerogel, or a fire
resistant material, or a fire resistant material, or combinations
of the foregoing materials. The present invention is not be limited
to silica aerogels, other metal oxide aerogels, e.g., alumina,
zirconia, tantala, titania, etc., and carbon aerogels are included.
Laminates of aerogel powder or powder impregnated fabrics, with
other fabrics--where the aerogel layer provides the physical
properties of repellancy, fire resistence, and thermal resistence
(as well as providing other barrier possibilities by absorption)
are included.
[0054] Fabric Manufacturing Embodiments of the Invention
[0055] The fibers described above are used in various embodiments
to produce fabrics 131. In one embodiment of the invention a fabric
is produced by the steps of: providing a multiplicity of fibers,
positioning the multiplicity of fibers in association with each
other to form the fabric, the fibers containing a void volume
located either in the fibers or between the fibers or both in the
fibers and between the fibers, and filling at least a portion of
the void volume with particles in the size range of 1-, 500 nm.
[0056] Various embodiments of method of filling the void volume
will be described. The embodiments include filling the void volume
with a solution that precipitates particles as it dries. In another
embodiment the void volume is filled with a solution containing a
colloidal suspension of particles that remain when the liquid
dries. In another embodiment the void volume is filled with a dry
powder by passing the fibers through a powder in a manner in which
the particles attach to the fibers. In another embodiment the void
volume is filled with a dry powder by passing the powder over the
fibers in a manner in which the powder particles attach to the
fibers. In another embodiment the void volume is filled a dry
powder by forcing the dry powder to enter the space using rollers.
In another embodiment the void volume is filled by forcing dry
powder to enter the space using a press.
[0057] In one of the embodiments of producing a fabric, the
particles are at least partially composed of a porous material. In
one of the embodiments of producing a fabric, the particles are at
least partially composed of a nanoporous material. In one of the
embodiments of producing a fabric, the particles are at least
partially composed of a nanoporous powdered material. In various
other embodiments of the invention the particles are at least
partially, composed of a solgel derived material, composed of an
aerogel-like material, composed of an aerogel, composed of an
inorganic material, composed of aggregates of inorganic particles,
contain an insulating material, contain a thermally insulating
material, composed of an insulating material, composed of a
thermally insulating material, contain a water repellant material,
contain a hydrophobic material, contain a hydrophobic, nanoporous
powdered material, composed of a water repellant material, composed
of a hydrophobic material, composed of a hydrophobic, nanoporous
powdered material, composed of a hydrophobic silica aerogel,
contain a fire resistant material, and/or composed of a fire
resistant material. The present invention is not be limited to
silica aerogels, other metal oxide aerogels, eg., alumina,
zirconia, tantala, titania, etc., and carbon aerogels, and
laminates of aerogel powder or powder impregnated fabrics, with
other fabrics--where the aerogel layer provides the physical
properties of repellancy, fire resistence, and thermal resistence
(as well as providing other barrier possibilities by
absorption.)
[0058] Incorporation of Existing Technologies
[0059] The embodiments described above include the use of known
manufacturing systems for processing fibers and processing fabrics.
The nanoporous powder can be any porous material that exhibits a
microstructure consisting of sub-micrometer pores and particles. In
some embodiments of the invention the powders should have a
composition such that the bulk material is not easily wet by pure
water; preferably, the bulk material would make a contact angle
greater than 90.degree. with a water droplet on its surface. The
powder can be applied to the fibers or to the woven fabric at any
time; preferably, by pressing the dry powder into the fibers or
fabric in a manner that results in effectively filling the
available void spaces. In some embodiments of the invention sol-gel
derived and aerogel-like materials are used.
[0060] The composite fabric consisting of the fibers and nanoporous
powder gives the fabric the properties of lightweight, water-proof,
thermal insulating, and fire retarding (if inorganic powders are
used). For example, a linen fabric treated with 19% by weight of
hydrophobic silica aerogel, completely shed water and its thermal
resistance improved by 31% over the same thickness of un-treated
fabric. The same treated fabric withstands a flame temperature of
525.degree. F. before scorching, 7 times longer than the untreated
fabric.
[0061] Aside from metal oxide aerogels, organic aerogels result
from the reactions of certain organic compounds, for example (1)
resorcinol with formaldehyde (known as RF aerogel), (2) melamine
with formaldehyde (known as MF aerogel) and (3) phenolic-furfural
with propanol. Such aerogels can be prepared in monolithic form and
have been employed in double layer capacitors. The present
invention is not be limited to silica aerogels, other metal oxide
aerogels, e.g., alumina, zirconia, tantala, titania, etc., and
carbon aerogels are included.
[0062] Many applications of aerogels require exposure to water or
atmospheric moisture. Normally aerogel materials have a large
affinity to absorb liquids such as water due to their high porosity
with pores open to the surface. However, present aerogels are
prepared either hydrophilic (i.e., absorb liquid water) or are only
temporarily hydrophobic (i.e., shed liquid water). Methods are
needed to either initially prepare hydrophobic aerogels, or treat
the dried and/or fully prepared aerogels to achieve permanent
hydrophobicity at ambient conditions as well as over a range of
temperature and pressure conditions.
[0063] As early as the 1970's, fluidized beds of highly dispersed
oxide and mixed oxide particles have been treated with various
organic silicon compounds and controlled amounts of steam to
produce products having hydrophobic properties. See, for instance,
U.S. Pat. No. 3,873,337, where Laufer et. al. describe the
fluidized bed treatment of highly dispersed, relatively low surface
area (130 m2/g), low porosity oxides with gaseous
dialkyldichlorosilane and water in an atmosphere of CO2. However,
such treatments do not consider the problems encountered to
hydrophobize the present day relatively thick, highly porous, high
surface area, monolithic aerogels that are essentially free of
dispersed particles.
[0064] Even the modification of hydrophilic surfaces of such
monolithic, low-density aerogels with methanol vapor by Lee et al.,
"Low-density, hydrophobic aerogels," Journal of Non-Crystalline
Solids, vol. 186 (1995), has produced hydrophobic aerogels for a
relatively short period. The very high porosity of such dried
aerogels, especially pores on open surfaces having an unusually
high affinity to water, contributes to the problem of preparing
permanently hydrophobic aerogels. Since many of the present-day
applications of the subject aerogels require a wide variety of
atmospheric exposures, the search continues to produce a
monolithic, transparent and thick aerogel having permanent
hydrophobicity at ambient conditions, yet still retain such
properties over a wide range of temperature and pressure
conditions.
[0065] U.S. Pat. No. 6,005,012 for a method for producing
hydrophobic aerogels by Hrubesh et al, patented Dec. 21, 1999
provides the following information, "Monolithic aerogels are a
special class of open-cell porous materials derived from the
supercritical drying of cross-linked inorganic or organic gels. By
today's standards, typical aerogels are porous materials in which
all structural entities (i.e., pores, particles) are smaller than
5000 .ANG. Such materials have ultrafine pore sizes of less than
5000 .ANG., continuous porosity, high surface areas of typically
400-1000 m2/g, and a microstructure composed of interconnected
colloidal-like particles or polymer chains with typical
characteristic diameters of less than 500.ANG. This microstructure
is responsible for the exceptional optical, acoustic, thermal, and
mechanical properties of such aerogels.
[0066] In most instances, it is essential to obtain such dried gels
in a monolithic state, i.e., free of cracks. Silica aerogels are
the most extensively described aerogel materials in the scientific
and patent literature. Aerogels of transition metal oxides, in
particular, are not as well described, and these aerogels are
expected to possess some properties that are not possible with
silica aerogels due to the presence of the transition metal. The
new characteristics of the aerogels will produce interesting new
materials for optical, magnetic, and catalytic applications.
[0067] The first aerogels were translucent pieces of porous silica
glass made by S. S. Kistler (U.S. Pat. No. 2,249,767). Kistler's
aerogels are prepared by forming silica hydrogels, which are
exchanged with alcohol and dried. The alcohol is supercritically
extracted in the drying process, and the resulting aerogel has a
density of about 0.05 g/cm3. Kistler's process is time-consuming
and laborious, and subsequent advances in the art have reduced the
processing time and increased the quality and porosity of
aerogels.
[0068] Other related art discusses the production of metal oxide
aerogels other than silica aerogels. Teichner et al., in Advances
in Colloid and Interface Science 5:245-273 (1976), provides a
general discussion of metal oxide aerogels, including oxides of
silicon, aluminum, titanium, zirconium, magnesium, nickel, copper,
and molybdenum. Lynch (U.S. Pat. No. 3,977,993) discusses a
modified Kistler method for making metal oxide aerogels. These
aerogels are made by preparing a hydrogel, exchanging the water in
the gel with an organic solvent, and then supercritically
extracting the organic solvent. The Lynch patent does not discuss
the peculiar problems in using different metals and the process
conditions necessary to ensure that the resulting aerogels form
large, transparent, intact (monolithic) solids.
[0069] European Patent No. 0382310 by Enichem discusses a process
for preparing monoliths of metal oxide aerogels. The process
comprises an acidic hydrolysis of a metal alkoxide, the gelation of
the resulting colloidal solution, and the supercritical drying of
the gel. The patent recognizes the difficulty in obtaining
monolithic aerogels with metals other than silicon. The patent
addresses the problem by adding a powder of a metal oxide to the
colloidal solution at the end of hydrolysis, before gelation.
[0070] Embodiments Using a Single Fiber made up of Strands of
Smaller Fibers
[0071] FIG. 1 shows a side view of a portion of a single fiber made
up of strands of smaller fibers. Nanosize particles at least
partially fill the inside spaces between the strands of the smaller
fibers and also are attached to the outside of the smaller fibers
and the single fiber. FIG. 2 is an end view of the fiber show in
FIG. 1. The present invention provides fibers and fabrics that have
insulating, waterproofing, and fire resistant properties. Fibers
and fabrics produced from the fibers are made water repellent,
fire-retardant and/or thermally insulating by filling the void
spaces in the fibers and/or fabrics with a powdered material. When
the powder is sufficiently finely divided, it clings tenaciously to
the fabric's fibers and to itself, resisting the tendency to be
removed from the fabric. Thus, this treatment offers substantial
long term improvement of the water repellant and thermal insulation
properties over the untreated fabric, while not adding much
additional weight to it.
[0072] In the present invention, the available void spaces in the
fibers and between strands of smaller fibers are filled with a
nanoporous material (powdered) whose particles and pores are so
small that the thermal resistance of the powder is higher than that
of the air that the powder is displacing.
[0073] As show in FIGS. 1 and 2, a single fiber is made up of
multiplicity of smaller single fiber strands. The smaller single
fiber strands can be either smaller single porous or smaller single
non-porous fiber strands. The poropus smaller single fiber strands
can have individual voids. At least some of the voids are at least
partially filled with particles in the size range of 1-100 nm. Also
there is a void volume between the smaller single porous or
non-porous fiber strands. At least a portion of the void volume is
at least partially filled with particles in the size range of 1-100
nm.
[0074] In one embodiment of the invention the particles are at
least partially composed of a porous material. In other embodiments
of the invention the particles are at least partially composed of a
nanoporous material, or are at least partially composed of a
nanoporous powdered material, or at least partially composed of a
solgel derived material, or at least partially composed of an
aerogel-like material, or at least partially composed of an
aerogel, or at least partially contain an insulating material, or
at least partially contain a thermally insulating material, or at
least partially composed of an insulating material, or at least
partially composed of a thermally insulating material, or at least
partially contain a water repellant material, or at least partially
contain a hydrophobic material, or at least partially contain a
hydrophobic, nanoporous powdered material, or at least partially
composed of a water repellant material, or at least partially
composed of a hydrophobic material, or at least partially composed
of a hydrophobic, nanoporous powdered material, or at least
partially composed of a hydrophobic silica aerogel, or at least
partially contain a fire resistant material, or at least partially
composed of a fire resistant material, or at least partially
composed of mixtures of the foregoing materials. The multiplicity
of smaller single porous fiber strands associated with each other
to form a single fiber.
[0075] FIG. 3 shows a schematic drawing of a fabric made of woven
fibers with the space between the woven fibers filled with nanosize
particles (diameters in the size range from 1-500 nm.) The fabric
is made of a multiplicity of fibers and the multiplicity of fibers
is associated with each other to form the fabric. The fabric
contains void volumes located either in the fibers or between the
fibers or both in the fibers and between the fibers. At least a
portion of the void volume at least partially filled with particles
in the size range of 1-500 nm. In various embodiments of the
invention the particles are at least partially composed of: a
porous material, or a nanoporous material, or a nanoporous powdered
material, or a solgel derived material, or an aerogel-like
material, or an aerogel, or an insulating material, or a thermally
insulating material, or an insulating material, or a water
repellant material, or a hydrophobic material, or a hydrophobic,
nanoporous powdered material, or a water repellant material, or a
hydrophobic silica aerogel, or a fire resistant material, or a fire
resistant material, or a combination of the foregoing materials. In
another embodiment of the present invention, the available void
spaces in fibers and fabrics are filled with a nanoporous material
(powdered) whose particles and pores are so small that the thermal
resistance of the powder is higher than that of the air that the
powder is displacing. The powdered nanoporous material is a
hydrophobic material that is not easily wet with water. Thus the
composite of fabric and powder has improved insulation and
water-proofing properties.
[0076] While the invention may be susceptible to various
modifications and alternative forms, specific embodiments have been
shown by way of example in the drawings and have been described in
detail herein. However, it should be understood that the invention
is not intended to be limited to the particular forms disclosed.
Rather, the invention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention as defined by the following appended claims.
* * * * *