U.S. patent application number 11/920103 was filed with the patent office on 2009-01-29 for process for creating spun yarn.
Invention is credited to N Satish Chandra, William F. Mcnally.
Application Number | 20090025359 11/920103 |
Document ID | / |
Family ID | 37397161 |
Filed Date | 2009-01-29 |
United States Patent
Application |
20090025359 |
Kind Code |
A1 |
Chandra; N Satish ; et
al. |
January 29, 2009 |
Process for creating spun yarn
Abstract
Input fibers to be used for the manufacture of textile
components are cut to a proper length [113]. The fibers are
metallized [115] with silver and copper. The metallized fibers are
opened [121] and blended [123] with other fibers. The blended
fibers are preferably opened again [125]. Then the blended fibers
are oriented [127] and drawn [129] into a sliver. Roving [140] may
be applied to the sliver to condense the fibers. The length of the
fibers, the denier of the fibers, the amount of metal coating and
composition of the metal coating are selected to provide an optimum
amount of metal ion discharge to have the proper antimicrobial
properties, while optimizing wound healing properties, and
minimizing manufacturing costs.
Inventors: |
Chandra; N Satish;
(Lansdale, PA) ; Mcnally; William F.; (Clarks
Summit, PA) |
Correspondence
Address: |
ZALE Patent Law
434 Lackawanna Ave., Suite 200
Scranton
PA
18503-2053
US
|
Family ID: |
37397161 |
Appl. No.: |
11/920103 |
Filed: |
May 8, 2006 |
PCT Filed: |
May 8, 2006 |
PCT NO: |
PCT/US06/17547 |
371 Date: |
November 7, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60679543 |
May 10, 2005 |
|
|
|
Current U.S.
Class: |
57/250 ;
264/172.11; 428/361; 57/232; 57/293 |
Current CPC
Class: |
D06M 11/83 20130101;
D04H 1/4234 20130101; Y10T 428/2907 20150115; D04H 1/74 20130101;
D04H 1/4382 20130101 |
Class at
Publication: |
57/250 ;
264/172.11; 428/361; 57/232; 57/293 |
International
Class: |
D06M 11/83 20060101
D06M011/83; D02G 1/02 20060101 D02G001/02; D02G 3/04 20060101
D02G003/04 |
Claims
1. A method of manufacturing a textile matrix having improved
anti-microbial properties comprising the steps of: a) preparing
input fibers [110], the preparation includes the following
substeps: i. providing input fibers [113] with a predetermined
length range, and ii. metallizing the input fibers [115]; b)
carding the metallized fibers [120] by the following sub-steps: i.
opening the metallized fibers [121] to separate the individual
fibers from each other, ii. blending the metallized fibers [123]
with other fibers, iii. orienting the blended fibers [127] in
generally the same direction to create a web, and iv. cross-lapping
the fibers [128] of the web.
2. The method of claim 1 wherein the step of providing input fibers
[113] with a predetermined length range comprises the step of:
providing input fibers [113] generally within the range of 1/2-8
cm.
3. The method of claim 1 wherein the step of providing input fibers
[113] with a predetermined length range comprises the step of:
providing input fibers [113] with an average fiber length of 3/4-6
cm.
4. The method of claim 1 wherein the step of providing input fibers
[113] with a predetermined length range comprises the step of.
providing input fibers [113] with an average fiber length of 1-3
cm.
5. The method of claim 1 wherein the step of providing input fibers
[113] with a predetermined length range comprises the step of:
providing input fibers [113] with an average fiber length of
approximately 2 cm.
6. The method of claim 1 wherein the step of metallizing the input
fibers [115] comprising the step of: coating at least a portion of
the input fibers with silver and copper at a ratio within the range
of 3-75% silver to copper by weight.
7. The method of claim 1 wherein the step of metallizing [115] the
input fibers comprising the step of: coating at least a portion of
the input fibers with silver and copper at a ratio within the range
of 9-60% silver to copper by weight.
8. The method of claim 1 wherein the step of metallizing [115] the
input fibers comprising the step of: coating at least a portion of
the input fibers with silver and copper at a ratio within the range
of 12-30% silver to copper by weight.
9. The method of claim 1 wherein the step of metallizing [115] the
input fibers comprising the step of: coating at least a portion of
the input fibers with silver and copper at a ratio of approximately
21% silver to copper by weight.
10. The method of claim 1 wherein the step of metallizing [115] the
input fibers comprising the step of: coating at least a portion of
the input fibers with zinc.
11. The method of claim 1 wherein the step of blending the
metallized fibers [123] with other fibers includes the step of
blending the metallized fibers [123] with one or more types of
fibers of the group consisting of: cotton fibers, cellulose fibers,
polyester fibers, acrylic fibers and nylon fibers.
12. The method of claim 1 wherein the step of blending the
metallized fibers [123] with other fibers includes the step of:
blending the metallized fibers [123] with bio-absorbable materials
intended to be dissolved within a living body.
13. The method of claim 1 wherein the step of blending the
metallized fibers [123] with other fibers includes the step of:
blending the metallized fibers [123] with other metallized fibers
having a different metal composition.
14. The method of claim 11 wherein the bio-absorbable material is
an alginate.
15. The method of claim 1 further comprising, after the substep of
blending [123], the step of: opening the blended fibers [125].
16. The method of claim 1, further comprising, after the step of
carding [120], the step of: needle punching the web [130].
17. A method of manufacturing textile components from an input
fiber having improved anti-microbial properties comprising the
steps of: a) preparing input fibers [110], the preparation includes
the following substeps: i. providing input fibers [113] with a
predetermined length range, and ii. metallizing the input fibers
[115]; b) carding the metallized fibers [120] by the following
sub-steps: i. opening the metallized fibers [121] to separate the
individual fibers from each other, ii. blending the metallized
fibers [123] with other fibers, iii. orienting the blended fibers
[127] in generally the same direction to create a web, and iv.
drawing the web [129] to create a sliver having fibers with
antimicrobial properties.
18. The method of claim 17 wherein the step of providing input
fibers [113] with a predetermined length range comprises the step
of: providing input fibers [113] generally within the range of
1/2-8 cm.
19. The method of claim 17 wherein the step of providing input
fibers [113] with a predetermined length range comprises the step
of: providing input fibers [113] with an average fiber length of
3/4-6 cm.
20. The method of claim 17 wherein the step of providing input
fibers [113] with a predetermined length range comprises the step
of: providing input fibers [113] with an average fiber length of
1-3 cm.
21. The method of claim 17 wherein the step of providing input
fibers [113] with a predetermined length range comprises the step
of: providing input fibers [113] with an average fiber length of
approximately 2 cm.
22. The method of claim 17 wherein the step of metallizing the
input fibers [115] comprising the step of: coating at least a
portion of the input fibers with silver and copper at a ratio
within the range of 3-75% silver to copper by weight.
23. The method of claim 17 wherein the step of metallizing [115]
the input fibers comprising the step of: coating at least a portion
of the input fibers with silver and copper at a ratio within the
range of 9-60% silver to copper by weight.
24. The method of claim 17 wherein the step of metallizing [115]
the input fibers comprising the step of: coating at least a portion
of the input fibers with silver and copper at a ratio within the
range of 12-30% silver to copper by weight.
25. The method of claim 17 wherein the step of metallizing [115]
the input fibers comprising the step of: coating at least a portion
of the input fibers with silver and copper at a ratio of
approximately 21% silver to copper by weight.
26. The method of claim 17 wherein the step of preparing the fibers
[110] comprises the step of: preparing the fibers [110] to have a
denier per fiber in the range of 0.5-50 dpf.
27. The method of claim 17 wherein the step of preparing the fibers
[110] comprises the step of: preparing the fibers [110] to have a
denier per fiber in the range of 0.7-30 dpf.
28. The method of claim 17 wherein the step of preparing the fibers
[110] comprises the step of: preparing the fibers [110] to have a
denier per fiber in the range of 1-10 dpf.
29. The method of claim 17 wherein the step of preparing the fibers
[110] comprises the step of: preparing the fibers [110] to have a
denier per fiber is approximately 3 dpf.
30. The method of claim 17 wherein the step of blending [123] the
metallized fibers with other fibers includes the step of blending
[123] the metallized fibers with one or more types of fibers of the
group consisting of: cotton fibers, cellulose fibers, polyester
fibers, acrylic fibers and nylon fibers.
31. The method of claim 17, further comprising, after the step of
carding [120], the step of: roving [140] to further condense the
fibers.
32. The method of claim 17, further comprising, after the step of
drawing [129] the web, the step of: spinning [150] the sliver into
a yarn having antimicrobial properties.
33. The method of claim 17 wherein the textile matrix includes one
of the group consisting of: antibiotics, antifungals, zinc coated
fibers, and hormones.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to, and claims priority from
U.S. patent application Ser. No. 10/938,868 "Process for Creating
Spun Yarn" filed May 10, 2005, and hereby incorporates by reference
this application as set forth in its entirety herein.
1. FIELD OF THE INVENTION
[0002] The present invention relates to an antimicrobial, absorbent
yarn textile matrix fostering a moist wound-healing environment
which minimizes or eliminates the possibility of infection, and is
especially useful as a component of a wound dressing.
BACKGROUND OF THE INVENTION
[0003] Silver has been used as an antimicrobial since ancient
times. It has been used to stop bacterial infections. Recent years
have seen a renewed interest in silver. This renewed interest is
driven in part by the development of antibiotic resistant bacteria,
such as methicillin-resistant Staphylococcus aureus (MRSA).
Conventional antibiotics have little or no effect on these
resistant bacteria. Resistant bacteria are especially problematic
in wounds, causing infections, destroying tissue, delaying the
healing process and causing unpleasant odors. Silver is a
broad-spectrum antibiotic that is effective against such resistant
bacteria. Even though these bacteria develop resistance to
antibiotics, they do not develop resistance to silver. There is a
current need for an antibiotic wound care product that uses silver
to treat and/or prevent MRSA and other infections caused by
resistant bacteria.
[0004] Silver is also known to exhibit wound-healing properties.
Expeditious wound healing benefits the patient by providing
increased comfort and decreased susceptibility to further infection
and secondary injury. There is a current need for wound care
products that utilize silver to increase the rate of wound
healing.
[0005] Many presently existing antimicrobial wound care products
have been used to treat infections, however, these lose their
effectiveness in a short period of time. This is especially true
for wound care products that contain silver in an ionic form. Ionic
silver is readily dissolved in an aqueous environment and
dissipated. Such dressings must be replaced frequently often
resulting in extreme pain or discomfort and inconvenience for the
patient as the dressing is removed and a new dressing is
applied.
[0006] Similarly, silver creams (including silver sulfadiazine)
must be consistently reapplied to the injured area, and the
dressing must be removed for reapplication of the cream. There is
currently a need for a wound care product that releases silver ions
over an extended period of time and which alleviates the need for
frequent removal or replacement of the dressing or application of
silver creams.
[0007] Silver may be commonly applied in ionic form as a silver
salt. Such salts can be irritating to the skin. Moreover, prolonged
contact with silver salts can cause argyria, which is characterized
by a pronounced, permanent ashen-gray skin discoloration, which can
be localized or universal. There currently is a need for a
non-irritating silver wound care product that does not rely on
silver salts for the delivery of silver ions. There is also a
current need for an ionic silver wound care product that does not
cause argyria.
[0008] Metallic silver is a costly substance. Silver wound care
products that use too much silver would be unduly expensive and
wasteful. On the other hand, silver wound care products that use
too little silver would be ineffective. There currently is a need
for a silver wound care product that enables the delivery of an
optimal dosage of silver to the wound area.
[0009] Silver is known to affect the operation of matrix
metalloproteinases (MMPs). Excessive MMPs are known to interfere
with and slow the wound healing process. Existing silver-based
wound care products inhibit MMPs too much, and also interfere with
the wound healing process. There is currently a need for a silver
wound care product that delivers a proper amount of silver, which
limits the activity of MMPs without unduly restricting MMPs
activity.
[0010] Other existing silver-based wound care products are made
from silver-plated films with limited flexibility. These
dramatically reduce the flexibility and comfort of the bandages.
Textile bandages are much more flexible and hence, much more
comfortable for patients. There is currently a need for a
silver-based wound care product that is more flexible and
comfortable.
SUMMARY OF THE INVENTION
[0011] The present invention may be embodied as a method of
manufacturing a textile matrix having improved anti-microbial
properties comprising the steps of: [0012] a) preparing input
fibers [110], the preparation includes the following substeps:
[0013] i. providing input fibers [113] with a predetermined length
range, and [0014] ii. metallizing the input fibers [115]; [0015] b)
carding the metallized fibers [120] by the following sub-steps:
[0016] i. opening the metallized fibers [121] to separate the
individual fibers from each other, [0017] ii. blending the
metallized fibers [123] with other fibers, [0018] iii. orienting
the blended fibers [127] in generally the same direction to create
a web, and [0019] iv. cross-lapping the fibers [128] of the
web.
[0020] The present invention may also be embodied as a method of
manufacturing textile components from an input fiber having
improved anti-microbial properties comprising the steps of: [0021]
a) preparing input fibers [110], the preparation includes the
following substeps: [0022] i. providing input fibers [113] with a
predetermined length range, and [0023] ii. metallizing the input
fibers [115]; [0024] b) carding the metallized fibers [120] by the
following sub-steps: [0025] i. opening the metallized fibers [121]
to separate the individual fibers from each other, [0026] ii.
blending the metallized fibers [123] with other fibers, [0027] iii.
orienting the blended fibers [127] in generally the same direction
to create a web, and [0028] iv. drawing the web [129] to create a
sliver having fibers with antimicrobial properties.
OBJECTS OF THE INVENTION
[0029] It is another object of the present invention to provide a
wound care product which employs silver metallized yarn capable of
releasing ionic silver to inhibit infections and facilitate wound
healing.
[0030] It is another object of the present invention to provide a
wound care product which is capable of releasing ionic silver,
copper and zinc ions over an extended period of time without the
use of irritating metal salts.
[0031] It is another object of the present invention to provide a
wound care product which is capable of releasing ionic silver which
does not cause argyria.
[0032] It is another object of the present invention to provide a
wound care product which maintains a moist wound-healing
environment while preventing the growth of bacteria and fungi.
[0033] It is another object of the present invention to provide a
wound care product which retains a moist wound environment, but
eliminates unpleasant odors.
[0034] It is another object of the present invention to provide an
anti-bacterial, and anti-fungal metallized yarn which employs a
large surface area for discharge of metal ions.
[0035] It is another object of the present invention to provide an
anti-bacterial, and anti-fungal metallized yarn in which the metal
ions do not become detached from the yarn substrate.
[0036] It is another object of the present invention to provide a
wound care product which enables the delivery of an optimal dosage
of silver ion.
[0037] It is another object of the present invention to provide a
wound care product which delivers a predetermined rate of silver
release, which limits MMP activity to a level roughly associated
with optimum wound healing.
[0038] It is another object of the present invention to provide an
anti-bacterial, and anti-fungal metallized yarn which can be used
in applications including hosiery and other knit-wear.
[0039] It is another object of the present invention to provide an
anti-bacterial, and anti-fungal metallized yarn which is easy and
inexpensive to manufacture.
[0040] It is another object of the present invention to provide a
combination of silver metallized and copper metallized yarn to
create wound care products which treat and/or prevent resistant
bacterial infections such as MRSA and fungal infections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] A complete understanding of the present invention may be
obtained by reference to the accompanying drawing, when considered
in conjunction with the subsequent detailed description, in
which:
[0042] FIG. 1 is a flowchart showing one embodiment of a process
for creating textile components according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] One embodiment of the present invention is a novel
antibiotic textile matrix made of a metallized yarn having
absorptive properties that are especially useful in wound care
products, such as wound dressings.
Metallized Fibers
[0044] The textile matrix of the invention includes silver coated
fibers. The silver coated fibers may be manufactured as described
in U.S. Pat. No. 4,042,737, entitled "Process For Producing Crimped
Metal-Coated Filamentary Materials, And Yarns And Fabrics Obtained
Therefrom," issued to Rohm and Haas Company (Philadelphia, Pa.), on
Aug. 16, 1977, hereby incorporated by reference as if set forth in
its entirety herein. Similar fibers are commercially available from
Noble Fiber Technologies sold under the tradename
X-static.RTM..
[0045] Copper has been known and proven to be a very effective
anti-fungal agent and also has other anti-microbial properties. It
is also very ductile and can be used to metallize a surface of a
textile substrate. The combination of silver with copper is very
effective in providing not only anti-bacterial, but also
anti-fungal properties.
[0046] Silver-coated fibers, such as the X-Static.RTM. product, can
be copper coated using conventional electrodeless copper chemistry.
Zinc-coated fibers can also be incorporated into the textile
matrix.
[0047] In addition to providing an antimicrobial effect, the
addition of the metallized fibers also reduce physical adherence of
the dressing to the wound site.
[0048] This reduced physical adherence reduces the amount that a
wound dressing sticks to, and pulls on the wound and making the
dressing more comfortable to wear. The reduced adherence also
decreases pain and discomfort when the dressing is removed or
replaced.
[0049] The preferred substrate of the silver-coated fiber is nylon.
The following table describes the preferred characteristics of the
metallized fibers:
TABLE-US-00001 Length Denier (cm) (dpf) Silver/Copper (% w/w)
Outside range 1/2-8 0.5-50 3%-75% Intermediate range 1/4-6 0.7-30
9%-60% Optimal range 1-3 1-10 12%-30% Ideal ~2 ~3 ~21
[0050] Using fibers having the length, denier per fiber and silver
to copper ratio, the optimum ion release is obtained to prevent
infections and optimizes healing.
Composition of the Textile Matrix
[0051] The textile matrix of the present invention is spun yarn
using fibers of the length, denier per fiber and silver to copper
ratio as specified in the table above.
[0052] The desirable antimicrobial properties and efficacy of the
textile matrix are determined using the Dow Corning Shake Flask
Test over 24 hours of the New NY State 63 Test for Bacteriostatic
Activity. Other tests included, but are not limited to ASTM E-2149
for a time period ranging from 10 minutes to 7 days. Preferably the
kill rate is not less than about 70%. More preferably the kill rate
is not less than about 85%, and ideally the kill rate is not less
than about 95%.
[0053] The present invention can also be used for other
applications such as being woven into material for odor prevention,
socks for athlete's foot prevention and into bedding liners to kill
dust mites, etc.
Method of Making
[0054] Manufacturing the textile matrix involves preparing the
input fiber, carding the fiber (includes sub-steps: opening the
silver-coated fiber, blending and orienting the fiber,
cross-lapping the fiber) and optionally, needle punching the
web.
[0055] Manufacturing a sliver involves preparing the input fiber,
carding the fiber (includes sub-steps: opening the silver-coated
fiber, blending and orienting the fiber, drawing the fiber) and
optionally roving to further condense the fiber.
[0056] Each of these steps is described in the ensuing text.
Manufacturing
[0057] Referring now to FIG. 1, the steps of the manufacturing
process according to one embodiment of the present invention are
shown.
1. Preparing the Input Fiber
[0058] In step 110, the metal coated fiber is prepared. One such
method is that described in U.S. Pat. No. 4,042,737, referenced
above.
[0059] In step 113, the metallized fiber is preferably manufactured
in the form of a continuous filament and then cut into short
segments having lengths as described above. The inventors have
surprisingly discovered that by using cut yarn, rather than staple
fiber, the properties of the final product are dramatically
improved. In step 115 the fibers are significantly easier to
metallize in the manufacturing process because there is less
clumping (adhesion to itself) of fibers. The inventors believe that
this improvement is facilitated by the general axial alignment of
the fibers after they are cut, relative to the random orientation
of the fibers that result from coating staple product. Another
factor that helps prevent clumping is the manufacture of the short
fibers from long fibers after aqueous processing, as opposed to
processing short (staple) fibers and allowing them to dry
together.
[0060] Copper-coated yarn is prepared by using commercially
available copper chemistry applied to silver-coated fibers.
2. Carding
[0061] In step 120, carding is accomplished using a traditional
carding process. A preferred carding machine is the Bematic card,
manufactured by Bettarinj & Serafirij Sarl. (Prato, Italy).
[0062] Carding blends the fibers together and orients them in
generally the same direction, i.e., generally parallel. Carding
includes the following sub-steps:
[0063] 2a. Opening the Silver-Coated Fiber with or without
Copper-Coated Fibers
[0064] In step 121, the metallized fibers are opened. When the
silver-coated fiber is processed wet and subsequently dried, it
clumps together (though not to the same extent as staple fiber that
is processed and then dried). The fiber is opened, to separate the
individual staple fibers from each other to enable it to be blended
with the alginate.
[0065] 2b. Blending and Orienting the Fibers
[0066] The silver-coated fiber and the absorbent fiber are then
blended in step 123 and oriented in step 127 to create a web.
[0067] Optionally, the blended fibers may be opened in step
125.
[0068] 2c. Drawing the Fiber
[0069] In step 129, the output of above steps is drawn to create a
sliver having absorbent and antimicrobial properties.
3. Roving to Further Condense the Fiber (Optional)
[0070] To further condense the fiber, the sliver may optionally be
put through a roving process in step 140.
4. Spinning
[0071] In step 150 the manufactured sliver is spun onto a bobbin to
be knit, woven, etc. in a traditional textile operation.
[0072] Optionally, the step of cross-lapping the fiber, step 128
and needle punching the web, step 130 may be employed as is known
in the prior art to result in a textile matrix.
Method of Using
[0073] The end result will result in textile components used in
making clothing and wound care products with optimum metal ion
release and superior anti-odor, anti-static, anti-microbial,
hydrodynamic, thermodynamic properties.
[0074] The percentage of metallized fiber, such as the
X-Static.RTM. product used in the textiles typically range from 2%
to 25% by weight, but overall from 1% to 75% of the spun yarn by
weight.
Example
[0075] Three textile matrix samples were manufactured according to
the foregoing procedure with varying amounts of silver thread and
cotton blend (10/90, and 50/50).
[0076] The matrix was tested for antimicrobial activity and
absorbance using the NY State 63 Test for Bacteriostatic Activity.
Five (5) 1'' inch squares of the textile matrix were used as
samples.
[0077] Ten bottom sections of 35.times.10 mm disposable tissue
culture dishes were placed in standard petri dishes containing 10
ml of sterile distilled water. 0.2 .mu.l of a 24 hour broth culture
containing 10.sup.5 organisms was placed in the center of each
disposable tissue culture dish. The test and control squares were
then placed in the disposable tissue culture dishes, with one side
in contact with the inoculum. The covers were than rep laced on the
standard petri dishes. The petri dishes were then placed on a level
shelf of an incubator at 37.degree. C. and incubated for 24 hours.
After 24 hours, the samples were removed from the petri dishes by
means of a flamed forceps and placed into 100 ml of Letheen broth
in an 8 oz. wide mouth jar. The jar was shaken vigorously for about
1 minute. Serial dilutions were made and placed on AATCC
bacteriostasis agar. Plates containing the agar were then incubated
for 24-48 hours at 37.degree. C. The percentage reduction of
inoculum by samples and controls was calculated.
TABLE-US-00002 Antimicrobial Activity % Silver % Cotton Kill Rate
10 90 >99.9% 50 50 >99.9%
Other Fibers
[0078] As descried in more detail below, the textile matrix may
include additional fibers other than the silver-coated fibers and
absorptive fibers. Examples include cotton, cellulose, polyester,
acrylic and nylon.
Other Therapeutic Agents
[0079] The textile matrix of the invention may also include other
antibiotics, such as doxycycline or other topical antibiotics. The
textile matrix may also include hormone treatments, such as
estrogen, to facilitate wound healing. For example, antibiotics and
hormones may be used in conjunction with the textile matrix as
described in U.S. Pat. No. 5,914,124.
[0080] The textile matrix may also include fibers, particles or
similar substrates coated with antibiotic (e.g., anti-microbial,
anti-bacterial, and/or anti-fungal) metals, such as copper and/or
zinc. A preferred combination textile matrix product includes
silver-coated fibers and copper-coated fibers.
[0081] Another preferred combination textile matrix product
includes silver-coated fibers and zinc-coated fibers.
[0082] While several presently preferred embodiments of the novel
invention have been described in detail herein, many modifications
and variations will now become apparent to those skilled in the
art. It is, therefore, to be understood that the appended claims
are intended to cover all such modifications and variations as fall
within the true spirit of the invention.
* * * * *