U.S. patent application number 11/915771 was filed with the patent office on 2008-11-20 for electrically conductive elastic composite yarn.
This patent application is currently assigned to NV BEKAERT SA. Invention is credited to Pol Speleers.
Application Number | 20080282665 11/915771 |
Document ID | / |
Family ID | 35058882 |
Filed Date | 2008-11-20 |
United States Patent
Application |
20080282665 |
Kind Code |
A1 |
Speleers; Pol |
November 20, 2008 |
Electrically Conductive Elastic Composite Yarn
Abstract
An electrically conductive elastic composite yarn comprises at
least one elastic member having a ratio N being drafted length Ld
over relaxed length Lr1 N being in the range of 1 to 10. The yarn
further comprises more than one metal filament wrapped around the
elastic member. The yarn is characterized in that each of the metal
filaments is twisted with at least one other of the metal
filaments.
Inventors: |
Speleers; Pol; (Waregem,
BE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
NV BEKAERT SA
|
Family ID: |
35058882 |
Appl. No.: |
11/915771 |
Filed: |
May 24, 2006 |
PCT Filed: |
May 24, 2006 |
PCT NO: |
PCT/EP2006/005008 |
371 Date: |
November 28, 2007 |
Current U.S.
Class: |
57/212 |
Current CPC
Class: |
D02G 3/12 20130101; D02G
3/441 20130101; D02G 3/328 20130101 |
Class at
Publication: |
57/212 |
International
Class: |
D02G 3/12 20060101
D02G003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 2, 2005 |
EP |
05104769.4 |
Claims
1. An electrically conductive elastic composite yarn comprising at
least one elastic member having a ratio N being drafted length Ld
over relaxed length Lr, said N being in the range of 1 to 10, said
yarn further comprising more than one metal filament wrapped around
said at least one elastic member, said metal filament having a
length that is equal to or greater than the drafted length Ld,
characterized in that each of said metal filaments is twisted with
at least one other of said filaments.
2. An electrically conductive elastic composite yarn as in claim 1,
wherein said metal filaments are wrapped around said at least one
elastic member using a number of turns per meter of said yarn in
the range of 150 turns per meter to 1400 turns per meter.
3. An electrically conductive elastic composite yarn as in claim 1,
wherein said metal filaments are twisted in a direction of twist,
said filaments are wrapped around said at least one elastic element
in the opposite direction of said direction of twist.
4. An electrically conductive elastic composite yarn as in claim 1,
wherein said yarn comprising at least a first group of metal
filaments being twisted with each other and a second group of metal
filaments being twisted with each other, said first group and said
second group being wrapped around said at least one elastic
member.
5. An electrically conductive elastic composite yarn as in claim 1,
wherein said yarn comprising more than 2 groups of metal filaments
being twisted with each other.
6. An electrically conductive elastic composite yarn as in claim 4,
wherein said first group is wrapped around said at least one
elastic element in S-direction, said second group being wrapped
around said at least one elastic member in Z-direction.
7. An electrically conductive elastic composite yarn as in claim 4,
wherein the number of groups being wrapped around said at least one
elastic member in S-direction is equal to number of groups being
wrapped around said at least one elastic member in Z-direction.
8. An electrically conductive elastic composite yarn as in claim 4,
wherein each of said groups comprises a number of metal filaments
M, said M being equal or more than 2, said M being less or equal to
550
9. An electrically conductive elastic composite yarn as in claim 8,
wherein said M is identical number for each of said groups of metal
filaments.
10. An electrically conductive elastic composite yarn as in claim
1, wherein said yarn comprises 1000 or less metal filaments.
11. An electrically conductive elastic composite yarn as in claim
1, wherein each of said metal filaments are twisted with at least
one other of said filaments using between 10 and 200 turns per
meter.
12. An electrically conductive elastic composite yarn as in claim
1, wherein for each section of the yarn having a relaxed length S,
the shortest of said metal filaments in said section having a
length F, said F being equal or larger than S, said F being less or
equal than 5*S.
13. An electrically conductive elastic composite yarn as in claim
1, wherein for each section of the yarn having a relaxed length S,
the length of each of said metal filaments is less or equal than
3*S.
14. An electrically conductive elastic composite yarn as in claim
1, wherein said N being in the range of 1.5 to 5.
15. An electrically conductive elastic composite yarn as in claim
1, wherein said at least one elastic element being a polyurethane
member of a natural or artificial rubber member.
16. An electrically conductive elastic composite yarn as in claim
1, wherein each of said metal filaments have an equivalent diameter
D, said D being equal or more than 1 .mu.m, said D being less or
equal to 150 .mu.m.
17. An electrically conductive elastic composite yarn as in claim
1, wherein each of said metal filaments is provided by metal fiber
bundle drawing operation.
18. An electrically conductive elastic composite yarn as in claim
1, wherein each of said metal filaments comprises copper or
copper-alloy, steel, nickel or nickel-alloy, aluminium or
aluminium-alloy or stainless steel.
19. A textile product comprising at least one electrically
conductive elastic composite yarn as in claim 1.
20. A textile product as in claim 19, wherein said textile product
is a woven fabric.
21. A textile product as in claim 20, wherein said yarn is present
as a weft or warp yarn.
22. A textile product as in claim 19, wherein said textile product
having an elongation at rupture of 100% to 400%.
23. A garment comprising a textile product as in claim 19.
24. A garment as in claim 23, wherein said yarn is present as a
loop.
25. A garment as in claim 23, wherein said garment being a seat
upholstery.
26. An electrically heating device comprising at least one
electrically conductive elastic composite yarn as in claim 1.
27. An electrically heating device comprising a textile product as
in claim 19.
28. The use of an electrically conductive elastic composite yarn as
in claim 1 as an antenna.
29. The use of an electrically conductive elastic composite yarn as
in claim 1 as a resistive heating element.
30. The use of a textile product as in claim 19, wherein said yarn
being used as an antenna.
31. The use of a textile product as in claim 30, wherein said yarn
being present as a loop-antenna.
32. The use of a textile product as in claim 19, wherein said yarn
being used as a resistive heating element.
33. The use of a garment as in claim 23, wherein said yarn being
used as an antenna.
34. The use of a garment as in claim 33, wherein said yarn being
present as a loop-antenna.
35. The use of a garment as in claim 23, wherein said yarn being
used as a resistive heating element.
36. The use of a garment as in claim 33, wherein said garment being
a seat upholstery.
Description
BACKGROUND
[0001] The present invention relates to an electrically conductive
elastic composite yarn, and a textile product comprising such yarn.
The invention further relates to the use of such textile
products.
[0002] Metal fibers and especially metal filaments are known as
elements of an electrically conductive yarn. As an example, an
electrically conductive yarn is used as a thermal fuse in U.S. Pat.
No. 5,927,060, or for evacuation of electrostatic charges build up
in a textile fabric such as described in U.S. Pat. No.
3,288,175.
[0003] Electrically conductive elastic composite yarns are known
from WO2004/097089. This document, upon which the preamble of the
present first claim is based, describes electrically conductive
elastic composite yarns comprising at least one elastic member
having a ratio N, this is the drafted length Ld over relaxed length
Lr of this elastic member, being in the range of 1 to 8. This yarn
may comprise more than one metal filament wrapped around the
elastic member. The metal filaments have a length which is at least
equal to the drafted length of the elastic member. The yarn has the
advantage that, when being subjected to elongation, the metal
filaments are not subjected to tensile stress.
[0004] The yarn may however suffer from some disadvantages. Because
of the very large length of metal filaments in the yarn per linear
meter of yarn, the metal filaments are very likely not to be in
contact with the outer surface of the elastic member. Because of
this, the metal filament has the liberty to displace randomly
around the elastic member when the latter is not under tension.
When this yarn is used to provide a textile product, some metal
filament loops may tend to stick out of the textile product due to
random deformation of the metal filaments. This phenomenon usually
occurs when the textile product was stretched repetitively.
[0005] This freedom of movement of the metal filaments may as well
cause some minor changes in electrical properties of the yarn,
because after each stretching of the textile, in casu the yarn,
there may occur a different number of contacting points between
adjacent loops of the same filament, or between several filaments
used to provide the same yarn.
[0006] The fact that metal filaments may lose contact with the
underlying elastic member, may as well cause more frequent filament
ruptures, or may disturb the production of the textile fabric in
which the yarn is used, or may disturb the use of the textile
product because of filaments pointing out of the surface of the
textile product.
[0007] The fact that the metal filaments are making contact with
the underlying elastic member, may increase drastically the
so-called flexlife of the electrically conductive elastic composite
yarn.
SUMMARY
[0008] Particular and preferred aspects of the invention are set
out in the accompanying independent and dependent claims.
Combinations of features from the dependent claims may be combined
with features of the independent claims as appropriate and not
merely as explicitly set out in the claims.
[0009] An aspect of the claimed invention provides an electrically
conductive elastic composite yarn. An aspect of the present
invention provides an electrically conductive elastic composite
yarn which has stable electrical conductive properties over life
time when repetitively stretched to a large extent. An aspect of
the present invention provides an electrically conductive elastic
composite yarn which can be repetitively stretched to a large
extent, meanwhile not having metal filaments buckling out of the
yarn or the textile product in which it is used. Another aspect of
the present invention provides an electrically conductive elastic
composite yarn of which the electrical resistance is easy to
calculate. Another aspect of the present invention provides an
electrically conductive elastic composite yarn which is easy to use
for providing textile products such as woven, braided or knitted
textile products, and garments comprising such textile products
comprising an electrically conductive elastic composite yarn as
subject of the invention.
[0010] A further aspect of the present invention provides a textile
product comprising an electrically conductive elastic composite
yarn, and a garment comprising a textile product comprising an
electrically conductive elastic composite yarn.
[0011] A further aspect of the present invention provides a textile
product and a garment, which has been incorporated in this product
or garment, an electrically conductive elastic composite yarn
serving as an operational safe antenna or resistive heating
element, having stable and predictable electrical properties and a
very high so-called flexlife.
[0012] An embodiment of the invention provides an electrically
conductive elastic composite yarn having the features as set out in
the characterizing portion of present claim 1. Use of such
electrically conductive elastic composite yarn provides a textile
product and/or a garment, wherein such electrically conductive
elastic composite yarn is used e.g. as an antenna. Advantageous
embodiments are set out in the dependent claims.
[0013] Surprisingly, it was found that the fact that for each metal
filament in the yarn, the metal filaments being twisted with at
least one other metal filament reduces the risk on metal filaments
displacing relatively freely during cycles of stretching and
relaxing the yarn. Within the yarn substantially all of an
elongating stress imposed on the composite yarn is carried by the
elastic member. This is because the conductive covering filaments
have a length that is at least equal to the drafted length of the
elastic member. All of this results in electrical properties of the
electrically conductive elastic composite yarn which are
predictable at the start, and remain unchanged during repetitive
stretching and relaxing cycles of the yarn. As the number of
contacting points between the twisted filaments remain unchanged
during stretching, and as, in case of more than two groups of
twisted filaments being wound around the same elastic member,
preferably in opposite direction, the number of contacting points
between the groups of filaments remain unchanged during stretching
and no significant deviation of electrical properties of the yarn
is noticed.
[0014] The twisted filaments, or alternatively more than one group
of twisted filaments, are wrapped around an elastic member.
[0015] The drafted length Ld of the elastic member is defined to be
that length to which the elastic member may be stretched and return
to within five percent (5%) of its relaxed (stress free) unit
length L.
[0016] The ratio N of the elastic member is defined as drafted
length Ld over relaxed length Lr. For yarns as subject of the
invention, N is in the range of 1 to 10, more preferably in the
range 1.5 to 5, or even more preferred in the range 1.5 to 3.
[0017] Preferably this elastic member is provided out of elastic
polymer or natural or artificial rubber. As an example,
polyurethane may be used. The elastic member may e.g. comprise only
one elastic filament, or may comprise a number of elastic
filaments, possibly twined to each other.
[0018] The filaments are metal filaments preferably having an
equivalent diameter D being equal or more than 1 .mu.m, and less or
equal to 150 .mu.m. More preferred, the equivalent diameter ranges
from 6 .mu.m to 65 .mu.m
[0019] The metal filaments used to provide a yarn as subject of the
invention preferably comprises copper or copper-alloy, nickel or
nickel-alloy, aluminium or aluminium-alloy, silver or silver alloy
or steel such as stainless steel. Possibly each filament is
provided out of a core metal, encompassed by one or more metal
layers. As an example each filament may comprise a steel core such
as a low carbon steel core being provided with a layer of an other
metal, preferably a metal being more electrically conductive than
the core, such as a copper-layer or a copper-alloy layer, an
aluminium layer or an aluminium-alloy layer, a silver or a
silver-alloy layer, a tin or a tin alloy layer. The layer is
preferably provided by cladding. One can also provide an outer
layer which leads to an improved resistance to galvanic corrosion
because of e.g. sweat or salt liquids, such as a metal layer
comprising nickel or a nickel-alloy, titan or a titan-alloy, silver
or a silver-alloy or such as a polymer layer.
[0020] Most preferred, the metal filaments are provided by a metal
fiber bundle drawing operation. The metal filaments, which obtain
in that case a substantially polygonal, usually penta- or hexagonal
cross section, are characterized by an equivalent diameter, which
is the diameter of an imaginary circle, having the same surface
area as the average surface area of a radial cross section of the
metal filament.
[0021] According to the present invention, each of the metal
filaments is twined with at least one other of the metal filaments
of the yarn as subject of the invention. The total number of
filaments used to provide a yarn as subject of the invention is
preferably in the range of 2 to 1000.
[0022] Possibly the metal filaments of the yarn as subject of the
invention could be grouped in at least two groups of metal
filaments, which metal filaments of each of said groups are twisted
with each other. It was found that preferably each of said groups
comprises M metal filaments, for which M being at least 2 and
preferably less or equal than 550. More preferred, M ranging from 2
to 280 such as 2, 9, 10, 50, 125 or 275.
[0023] As at least 2 and preferably more than 2 metal filaments are
used, which are twisted to each other, the yarn, when subjected to
a stretching operation, is less vulnerable to filament ruptures,
because of the twisting of the filaments. The tension which may be
imposed on the metal filaments, are not to be born by only one
metal filament, but are substantially equally divided amongst all
the filaments present. An additional advantage is that, in case one
filament is broken, the electrical properties of the yarn itself is
few or not influenced due to the numerous contacts between the
filaments being twisted together, and between the different groups
of filaments in case such different groups are present. It was
found that the electrical properties of the yarn are not influenced
as long as not more than 80% of the filaments are broken.
[0024] It was found that for each representative section of the
yarn as subject of the invention having a relaxed length S,
preferably the shortest metal filament in this section has a length
F for which F being larger or equal to S, and F being smaller or
equal to 5*S, more preferred smaller than 3.5*S.
[0025] Further it was found that for each representative section of
the yarn as subject of the invention having a relaxed length S,
preferably the length of each of the metal filaments in this
section is smaller or equal to 3*S.
[0026] Each of the metal filaments is twisted with at least one
other metal filament. Preferably a number of turns per meter
between 10 and 200 is used.
[0027] Possibly at least two groups of metal filaments, which
filaments are twisted with each other, are used to provide a yarn
as subject of the invention. It was found that when at least two
groups of metal filaments are present, the number of contacting
points between the groups of filaments remain unchanged during
stretching, resulting in no significant deviation of electrical
properties of the yarn. This was especially the case when at least
one group is wrapped around the elastic member in a first
direction, whereas at least one of the other groups of metal fibers
is wrapped in the opposite direction around the elastic member.
This also contributes to a reduction of the liveliness of the yarn
as subject of the invention. Possibly the groups of metal filaments
are provided around the elastic member by braiding, which is also
to be understood as wrapping in the spirit of the present
invention.
[0028] In order to further reduce the liveliness of the yarn as
subject of the invention, so providing a yarn which is more
suitable and easy to process in textile production processes such
as braiding, weaving or knitting, preferably the direction of
twisting is opposite to the direction used to wrap the group of
fibers around the elastic element.
[0029] Most preferred, the number of groups of filaments being
wrapped in on direction around the elastic member, say the
S-direction, is equal to the number of groups of filaments being
wrapped in the opposite, say the Z-direction around the elastic
member.
[0030] Possibly a group of metal filaments comprises two or more
subsets, each subset comprising at least two metal filaments being
twisted with each other. The subsets are then twined with each
other in order to provide the group of metal filaments, which on
its turn is wrapped around the elastic member.
[0031] The number of turns per linear meter of relaxed yarn of the
filaments wrapped around the elastic member, or in case of more
than one group of metal filaments, the number of turns per linear
meter of relaxed yarn of each of the groups wrapped around the
elastic member is preferably between 150 and 1400. The numbers or
turns per linear meter of yarn may be equal for each of the groups
of metal filaments in case the yarn comprises more than one group
of metal filaments.
[0032] According to the present invention, the electrically
conductive elastic composite yarn as subject of the invention may
be used to provide a textile product, e.g. a braided, woven or
knitted textile product. The electrically conductive elastic
composite yarn has the advantage that there are few or no metal
filaments pointing out of the yarn, which enabled a smooth and
trouble free incorporation of the yarn in the textile product.
[0033] Preferably, the electrically conductive elastic composite
yarn is used to provide an elastic tape like woven fabric, in which
the electrically conductive elastic composite yarn is present as a
warp element. Possibly, the woven tape is woven so-to-say around
the electrically conductive elastic composite yarn, which are
present as non interwoven warp elements in a pocket. The other warp
elements may comprise elastic yarns as well.
[0034] A tape-like woven structure with incorporated electrically
conductive elastic composite yarns as subject of the invention may
so be obtained. It was found that such tapes, when subjected to
repetitive elongation, has no tendency to show metal filaments
sticking out of the surface of the woven textile product.
[0035] A similar property was found for braided and knitted textile
products.
[0036] The textile product as subject of the invention may have an
elongation at rupture in the range of 100% to 400%, more preferred
in the range of 200% to 350%. This elongation is measured by
subjecting a textile sample with a given length to an elongation
until rupture of one of the yarns comprised in the fabric. The
length at rupture divided by the length of the textile fabric prior
to elongation, and expressed in percentages is understood as the
above-mentioned elongation at rupture.
[0037] It was found that the textile product may be used to provide
a garment, wherein the electrically conductive elastic composite
yarn, incorporated in the textile product, is used as e.g. an
antenna. It was found that preferably a electrically conductive
elastic composite yarn, being present in a loop shape in the
garment, may function very well as a loop antenna. Especially
tape-like woven textile products are suitable for such use. By
integrating the electrically conductive elastic composite yarn into
a woven tape and by connecting the two ends of the yarn, by means
of e.g. electrical conductive snap fasteners, this tape could work
as loop antenna when worn around e.g. the body of a person.
[0038] Alternatively, the textile product comprising an
electrically conductive elastic composite yarn as subject of the
invention may function as a heatable textile product, wherein the
electrically conductive elastic composite yarn functions as a
resistive heating element. For the intended applications, the
textile product may be part of a garment. Especially garments being
seat upholstery, e.g. car seat upholstery, benefits from the stable
and reliable electrical properties of the yarn as subject of the
invention under any stretched condition. Further it was noticed
that the so-called flex-life of the resistive element was
significantly improved. Flex-life is to be understood as the
resistance to rupture of the yarn under repetitive bending
conditions. As an alternative, the textile product or the yarn as
subject of the invention itself may be part of a heating device
which is integrated in the car seat as such, usually between the
foamed part of the seat and the upholstery.
[0039] As further alternative used, the yarn as subject of the
invention or a textile product as subject of the invention may be
used as part of an electrode for detection and/or measuring the
presence of body liquids such as sweat or urine, or as a part of a
sensor for measuring and detecting hart beat or respiration
monitoring.
[0040] As further alternative, the yarn as subject of the invention
or a textile product as subject of the invention may be used as
leadwire which connects different electronic devices to each other
such as batteries, PCB's, monitoring devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention will now be described hereinafter, by way of
example only, with reference to the accompanying drawings
wherein
[0042] FIG. 1, FIG. 2, FIG. 3, FIG. 4 and FIG. 5 show schematically
a yarn in accordance with examples of the invention;
[0043] FIG. 6 shows schematically a tape-like woven structure in
accordance with an example of the invention;
[0044] FIG. 7 shows schematically a garment comprising a textile
product in accordance with an example of the invention;
[0045] FIG. 8 shows schematically a car seat comprising a textile
product in accordance with an example of the invention as
resistance heating element.
DESCRIPTION OF THE PARTICULAR EMBODIMENTS
[0046] FIG. 1 shows schematically a yarn 101 in accordance with an
example of the invention, which yarn comprises an elastic member
110, which is wrapped with mutually twisted metal filaments,
together indicated 120. As an example, elastic member 110 is a
natural rubber filament, whereas the metal filaments 120 comprise
275 filaments of alloy stainless steel AISI 316L, and having an
equivalent diameter of 12 .mu.m. They are twisted to each other
using 100 turns per meter in Z direction, and subsequently are
wrapped in S direction around the elastic member 110 using 1100
turns per meter.
[0047] The ratio N of drafted length Ld over relaxed length Lr of
the elastic member is 1,4. For a relaxed length S being 100 mm of
the yarn 101, the length of each of the filaments is substantially
equal, thus is the same as the shortest length F of a metal
filament. In this embodiment F is 140 mm.
[0048] The electrical resistance of this yarn 101 is 21
ohm/meter.
[0049] Alternatively, the metal filaments 120 comprise 90 filaments
of alloy stainless steel AISI 316L, and having an equivalent
diameter of 14 .mu.m. They are twisted with each other using 100
turns per meter in Z direction, and subsequently are wrapped in S
direction around the elastic member 110 using 1000 turns per
meter.
[0050] An alternative yarn 201 in accordance with an example of the
invention is shown schematically in FIG. 2. The yarn 201 comprises
an elastic member 210, which is wrapped with two groups 221 and 222
of mutually twisted metal filaments. As an example, elastic member
210 is natural rubber filament, whereas each of the groups 221 and
222 of metal filaments comprises 550 filaments of alloy 316L having
an equivalent diameter of 12 .mu.m. The first group 221 is twisted
to each other using 175 turn per meter in S direction, and
subsequently is wrapped in Z direction around the elastic member
210 using 1000 turns per meter. The second group 222 is twisted to
each other using 175 turns per meter in Z direction, and
subsequently is wrapped in S direction around the elastic member
210 using 1000 turns per meter.
[0051] The ratio N of drafted length Ld over relaxed length Lr of
the elastic member 210 is 1,4. For a relaxed length S of 100 mm of
the yarn 201, the length of each of the filaments either from the
first group 221 or second group 222 is substantially equal, thus is
the same as the shortest length F of a metal filament. In this
case, F is 140 mm.
[0052] The electrical resistance of this yarn 201 is 10
ohm/meter.
[0053] An alternative yarn 301 in accordance with an example of the
invention is shown schematically in FIG. 3. The yarn 301 comprises
an elastic member 310, which is wrapped with eight groups 321, 322,
323, 324, 325, 326, 327 and 328 of mutually twisted metal
filaments. As an example, elastic member 310 is natural rubber
filament, whereas each of the groups 321, 322, 323, 324, 325, 326,
327 and 328 of metal filaments comprises 550 filaments of alloy
AISI 316L, and having an equivalent diameter of 12 .mu.m. The
groups 221, 323, 325 and 327 are twisted to each other using 175
turns per meter in S direction. The groups 322, 324, 326 and 328
are twisted to each other using 175 turns per meter in Z direction.
The eight groups are then braided around the elastic member 310 in
such a way that the groups 321, 323, 325 and 327 follow
substantially a path as if they would be wrapped in Z direction
around the elastic member 310. The groups 322, 324, 326 and 328
follow substantially a path as if they would be wrapped in S
direction around the elastic member 310. All groups 321, 322, 323,
324, 325, 326, 327 and 328 make 1000 turns per meter of yarn.
[0054] The ratio N of drafted length Ld over relaxed length Lr of
the elastic member 310 is 1,5. For a relaxed length S of 100 mm of
the yarn 301, the length of each of the filaments either from the
groups 321, 322, 323, 324, 325, 326, 327 and 328 is substantially
equal thus is the same as the shortest length F of a metal
filament. In this case, F is 150 mm. The electrical resistance of
this yarn 301 is 5 ohm/meter.
[0055] An alternative yarn 401 in accordance with an example of the
invention is shown schematically in FIG. 4. The yarn 401 comprises
an elastic member 410, which is wrapped with two groups 421 and 422
of mutually twisted metal filaments. The elastic member 410
comprises more than one, e.g. three elastic monofilaments 411, 412
and 413, being natural rubber filaments, whereas each of the groups
421 and 422 of metal filaments comprises 180 filaments of alloy
316L having an equivalent diameter of 14 .mu.m. The first group 421
is twisted around each other using 100 turns per meter in S
direction, and subsequently is wrapped in Z direction around the
elastic member 410 using 1000 turn per meter. The second group 422
is twisted around each other using 175 turns per meter in Z
direction, and subsequently is wrapped in S direction around the
elastic member 410 using 1100 turns per meter.
[0056] The ratio N of drafted length Ld over relaxed length Lr of
the elastic member 410 is 1,5. For a relaxed length S of 100 mm of
the yarn 401, the length of each of the filaments either from the
first group 421 or second group 422 is substantially equal thus is
the same as the shortest length F of a metal filament. F is 150
mm.
[0057] The electrical resistance of this yarn 401 is 22
ohm/meter.
[0058] An alternative yarn 501 in accordance with an example of the
invention is shown schematically in FIG. 5. The yarn 501 comprises
an elastic member 510, which is wrapped with two groups 521 and 522
of mutually twisted metal filaments. The elastic member 510
comprises more than one, e.g. three elastic monofilaments 511, 512
and 513, being provided out of natural rubber, whereas each of the
groups 521 and 522 of metal filaments comprises 7 filaments of
copper clad steel, and having an equivalent diameter of 63 .mu.m.
The first group 521 is twisted to each other using 60 turns per
meter in Z direction, and is wrapped in Z direction around the
elastic member 510 using 850 turns per meter. The second group 522
is twisted to each other using 60 turns per meter in Z direction,
and is wrapped in S direction around the elastic member 510 using
700 turns per meter.
[0059] The ratio N of drafted length Ld over relaxed length Lr of
the elastic member 510 is 3,0. For a relaxed length S of 100 mm of
the yarn 501, the length of each of the filaments from the first
group is the shortest length F of a metal filament, being 300
mm.
[0060] The electrical resistance of this yarn 501 is 5
ohm/meter.
[0061] Each of the above mentioned yarns in accordance with the
examples of the invention may be used to provide a textile product.
Such a textile product may, as an example, be a woven textile
product 601 as schematically shown in FIG. 6.
[0062] The woven fabric 601 has a warp direction 610 and a weft
direction 611. A number of elastic electrically conductive yarns
620 in accordance with an example of the invention are present as
elements in warp direction 610. The woven fabric has substantially
three zones, being two side zones 630 and 631, between which a
pocket-like zone 640 is located. The yarns 620 are provided in the
interior of the pocket-like zone. In order to make electrical
contact with an electronic device with which the woven textile
product is to be connected, two snap fasteners 650 are provided,
preferably in stainless steel.
[0063] The elongation at rupture of the textile woven product is
310%
[0064] FIG. 7 shows schematically a garment comprising a textile
product in accordance with an example of the invention.
[0065] The garment, either e.g. a vest or as shown in FIG. 7, a
shirt 701, may comprise one or more textile products 711, 712, 713,
714 in accordance with examples of the invention for serving
multiple purposes such as sweat detection, heart beat detection or
monitoring, blood pressure measurement, or any other known
application of electrically conductive textiles in garments. The
textile products 711, 712, 713, 714 may serve as well as an antenna
for receiving or sending EM-waves. Preferably in this case, the
textile products 711, 712, 713 are used as they are provided in the
shape of a loop antenna, since both ends of the tape, and both ends
of the yarn in accordance with an example of the invention are
approaching each other in such a way that the yarn or yarns are
present according to a loop-shape. Preferably the textile products
711, 712, 713, 714 are similar to the tape like woven fabric 601 as
shown in FIG. 6. The electronic device such as a transducer or
receiver, is coupled to the two snap fasteners 650.
[0066] Alike, the garment being pants 702 may comprise a textile
product 721 in accordance with an example of the invention
comprising yarns in accordance with an example of the invention.
Preferably the textile product 721 is similar to the tape like
woven fabric 601 as shown in FIG. 6. The textile product 721 may
serve as well as a loop antenna for receiving or sending EM-waves.
The electronic device such as a transducer or receiver, is coupled
to the two snap fasteners 650, and in this case may easily be
carried in the pocket 722 by the person wearing the pants. The snap
fastener or alike coupling element may extend from the textile
product 721 to the inner side of the pocket.
[0067] As an other alternative, the garment being a belt 703, may
comprise a textile product 731 in accordance with an example of the
invention comprising yarns in accordance with an example of the
invention. Also in this case, the textile product 731 may be used
as a loop antenna.
[0068] Another use is shown in FIG. 8. A car seat 801 may be
provided with a textile product 810 in accordance with an example
of the invention, comprising yarns in accordance with an example of
the invention serving as electrically heating yarns 812 by means of
resistance heating. The yarns 812 in accordance with an example of
the invention may be coupled to an electrical device providing the
necessary current for use in the heatable textile, by means of two
cables 813, each being coupled to an electrode 811 to which the
yarns 812 are coupled. The electrodes 811 itself may as well
comprise yarn in accordance with an example of the invention, being
it with a smaller electrical resistance as the yarns 812.
[0069] The textile product 810 may be provided as a device being
located between the foamed part 820 of the seat, or as an
integrated part of the upholstery of the car seat.
[0070] An aspect of the invention can provide an electrically
conductive elastic composite yarn which comprises at least one
elastic member having a ratio N being drafted length Ld over
relaxed length Lr, N being in the range of 1 to 10. The yarn
further comprises more than one metal filament wrapped around the
elastic member. The yarn is characterized in that each of the metal
filaments is twisted with at least one other of the metal
filaments.
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