U.S. patent application number 11/075198 was filed with the patent office on 2005-12-22 for electrically conductive yarn.
This patent application is currently assigned to W. Zimmermann GmbH & Co. KG. Invention is credited to Maier, Georg, Nusko, Robert, Parzl, Adi.
Application Number | 20050282009 11/075198 |
Document ID | / |
Family ID | 32031478 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050282009 |
Kind Code |
A1 |
Nusko, Robert ; et
al. |
December 22, 2005 |
Electrically conductive yarn
Abstract
A yarn that is electrically conductive, that can be elongated
considerably, at least briefly, without loss of conductivity, and
that exhibits improved elongation properties.
Inventors: |
Nusko, Robert; (Wiesent,
DE) ; Parzl, Adi; (Regensburg, DE) ; Maier,
Georg; (Altentann, DE) |
Correspondence
Address: |
CROCKETT & CROCKETT
24012 CALLE DE LA PLATA
SUITE 400
LAGUNA HILLS
CA
92653
US
|
Assignee: |
W. Zimmermann GmbH & Co.
KG
|
Family ID: |
32031478 |
Appl. No.: |
11/075198 |
Filed: |
March 7, 2005 |
Current U.S.
Class: |
428/375 ;
264/103 |
Current CPC
Class: |
D02G 3/12 20130101; D02G
3/328 20130101; Y10T 428/2933 20150115; D02G 3/441 20130101 |
Class at
Publication: |
428/375 ;
264/103 |
International
Class: |
D02G 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2002 |
DE |
DE 102 42 785.2 |
Feb 13, 2003 |
DE |
DE 103 05 872.9 |
Sep 15, 2003 |
WO |
PCT/DE03/03059 |
Claims
We claim:
1. An electrically conductive yarn comprising: at least one elastic
core thread; at least one electrically conductive thread that is
wound around the core thread; and at least one binding thread that
is wound around the core thread, wherein the extensibility of the
entire electrically conductive yarn is restricted by the binding
thread.
2. The electrically conductive yarn according to claim 1, wherein
above a certain tensile load, the binding thread effects a
disproportionate rise in the restoring force of the electrically
conductive yarn, said disproportionate rise in the restoring force
occurring prior to the loss of the conductivity of the yarn.
3. The electrically conductive yarn according to claim 1 wherein
the core thread is composed of a rubber elastic material.
4. The electrically conductive yarn according to claim 1 wherein
the elastic core thread exhibits an elongation at break of at least
50%.
5. The electrically conductive yarn according to claims 1 or 2, in
which the rubber elastic core thread is selected from the group
consisting of natural rubber, synthetic rubber, polyester elastane,
polyether elastane, modified polyester, post-cross-linked
thermoplast, polyester-polyurethane elastomer, and
polyether-polyurethane elastomer.
6. The electrically conductive yarn according to claim 1 where the
yarn exhibits a maximum permanent elongation of no more than about
5% without loss of electrical conductivity after elastic elongation
by at least 15% in the lengthwise direction.
7. The electrically conductive yarn according to claim 1, wherein
the electrically conductive thread comprises a monofilament metal
wire with a diameter between about 0.01 and 0.1 mm.
8. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread comprises a metallic-coated
synthetic fiber.
9. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread comprises monofilament
silver-coated fibers.
10. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread comprises a metallic
multifilament yarn.
11. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread comprises a silver-coated
multifilament yarn.
12. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread comprises stainless steel
fibers.
13. The electrically conductive yarn according to claim 1 wherein
the binding thread is wound around outside the core thread, said
core thread being enwound with the electrically conductive
thread.
14. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread is wound around outside the core
thread, said core thread being enwound with the binding thread.
15. The electrically conductive yarn according to claim 1 in which
the electrically conductive thread is wrapped around the elastic
core thread at least about 1,000 times per meter of yarn.
16. The electrically conductive yarn according to claim 1 in which
the binding thread is wrapped around the elastic core thread at
least about 1,000 times per meter of yarn.
17. The electrically conductive yarn according to claim 1 wherein
the electrically conductive thread and the binding thread are
wrapped around the elastic core thread in opposite directions.
18. A method for manufacturing an electrically conductive yarn
comprising the steps of: mechanically drawing the elastic core
thread on drawing equipment; passing the drawn core thread through
a hollow spindle bearing the electrically conductive thread and
rotating around its longitudinal axis; and passing the drawn core
thread, already singly enwound with an electrically conductive
thread, through a second hollow spindle bearing a binding thread
and rotating around its longitudinal axis, said second hollow
spindle rotating counter to the first hollow spindle.
19. A fabric comprising at least one electrically conductive yarn,
said yarn comprising at least one elastic core thread, at least one
electrically conductive thread that is wound around the core
thread, and at least one binding thread that is wound around the
core thread, wherein the extensibility of the entire electrically
conductive yarn is restricted by the binding thread.
20. A method for transmitting an electrical signal comprising:
providing an electrically conductive yarn comprising at least one
elastic core thread, at least one electrically conductive thread
that is wound around the core thread, and at least one binding
thread that is wound around the core thread, wherein the
extensibility of the entire electrically conductive yarn is
restricted by the binding thread; providing an electrical signal
source; coupling the yarn to the signal source; and transmitting
the electrical signal.
21. The method of claim 20 wherein the the electrical signal is
selected from the group consisting of an analog signal, a digital
signal, and both an analog and a digital signal.
22. A method for supplying electrical power to an electronic device
comprising: providing an electrically conductive yarn comprising at
least one elastic core thread, at least one electrically conductive
thread that is wound around the core thread, and at least one
binding thread that is wound around the core thread, wherein the
extensibility of the entire electrically conductive yarn is
restricted by the binding thread; providing an electrical power
source; coupling the yarn to the power source and the electronic
device; and transmitting electrical power from the power source to
the electronic unit through the yarn.
23. A method for generating heat by means of electric current, said
method comprising: providing an electrically conductive yarn
comprising at least one elastic core thread, at least one
electrically conductive thread that is wound around the core
thread, and at least one binding thread that is wound around the
core thread, wherein the extensibility of the entire electrically
conductive yarn is restricted by the binding thread; providing an
electrical power source; coupling the yarn to the power source; and
transmitting electrical power from the power source through the
yarn whereby generating heat.
24. A method for shielding electromagnetic fields comprising the
step of providing an electrically conductive yarn, said yarn
comprising at least one elastic core thread, at least one
electrically conductive thread that is wound around the core
thread, and at least one binding thread that is wound around the
core thread, wherein the extensibility of the entire electrically
conductive yarn is restricted by the binding thread.
25. A method for dissipating static charges comprising the step of
providing an electrically conductive yarn, said yarn comprising at
least one elastic core thread, at least one electrically conductive
thread that is wound around the core thread, and at least one
binding thread that is wound around the core thread, wherein the
extensibility of the entire electrically conductive yarn is
restricted by the binding thread.
26. A humidity sensor comprising an electrically conductive yarn,
said yarn comprising at least one elastic core thread, at least one
electrically conductive thread that is wound around the core
thread, and at least one binding thread that is wound around the
core thread, wherein the extensibility of the entire electrically
conductive yarn is restricted by the binding thread.
27. A strain sensor comprising an electrically conductive yarn,
said yarn comprising at least one elastic core thread, at least one
electrically conductive thread that is wound around the core
thread, and at least one binding thread that is wound around the
core thread, wherein the extensibility of the entire electrically
conductive yarn is restricted by the binding thread.
Description
[0001] This application is a continuation-in-part of International
Application No. PCT/DE2003/003059, filed Sep. 15, 2003, which
claims priority to German Patent Application DE 102 42 785.2 filed
Sep. 14, 2002 and German Patent Application DE 103 05 872.9 filed
Feb. 13, 2003.
FIELD OF THE INVENTIONS
[0002] The present invention relates to elastic, electrically
conductive yarns, their use and methods for their manufacture.
BACKGROUND OF THE INVENTIONS
[0003] Several methods are known for manufacturing electrically
conductive yarns. For example, metal wires, wire mesh or metallized
yarns have long been incorporated directly in fabrics to dissipate
electrostatic charge. These fabrics are often difficult to produce
on a loom and, due to the exposed wires, bear little optical
resemblance to textiles and/or feel metallic to the touch.
[0004] Furthermore, methods for manufacturing so-called staple
yarns are known. Essentially, they involve spinning short textile
fibers together with short and very fine metal fibers into a yarn.
Depending on the metal content, these yarns have more or less
textile or metallic properties. Staple yarns with good electrical
conductivity exhibit a metallic appearance and surface feel.
[0005] Methods are also known in which centrally carried metal
wires are single- or double-wound with textile. Since it is
substantially the wire that determines the tensile strength in
these yarns, relatively thick wires with diameters greater than 0.1
mm are usually employed. Such yarns are comparatively rigid and
thus unusable for textile applications.
[0006] EP 250 260 describes how also thin wires can be employed in
the core of an enwound yarn by enwinding with wire and textile
thread, fed in parallel. In this arrangement, the central textile
thread provides for tensile strength, while the parallel thin wire
produces the electrical conductivity of the yarn. However, such
yarns are not particularly extensible.
[0007] CH 690 686 describes the manufacture of a composite yarn of
textile roving and monofilament metal thread. During the
yarn-spinning process on a ring spinner, a coated metal wire is
added centrally to the roving. In the thermal treatment following
the spinning process, the melting coating adheres the central wire
to the spun textile sheathing. These yarns, too, do not exhibit
good extensibility.
[0008] None of the above-described yarns can be appreciably
elastically extended without loss of electrical conductivity, since
the conductive threads either break or deform plastically.
[0009] The specifications of U.S. Pat. No. 4,776,160, U.S. Pat. No.
5,881,547 and U.S. Pat. No. 5,927,060 each describe yarns in which
electrically conductive yarns are wound around centrally arranged
textile threads. This arrangement facilitates in principle a
certain elongation of the entire yarn unit without causing the yarn
or the conductive wrapping to tear.
[0010] U.S. Pat. No. 5,881,547 teaches the production of a
high-tensile-strength, electrically conducting yarn for employment
in fencing wear. These yarns are composed of a non-electrically
conductive core thread and a double, crossed wrapping with
stainless steel wire. Due to the large diameter of the stainless
steel wires used, in the range of 0.6 mm to 1.2 mm, they are very
rigid, hardly extensible and by no means elastic.
[0011] Both U.S. Pat. No. 4,776,160 and U.S. Pat. No. 5,927,060
mention the use of flexible, extensible core threads for
manufacturing conductive yarns with good textile properties. U.S.
Pat. No. 4,776,160 mentions, as materials for the core thread,
thermoplasts such as nylon, polyester, rayon, acrylic, PEEK, PBS,
PBI, polyolefins (PE, PP) and liquid crystal polymers,
polycarbonate, polyvinyl alcohol and aramid fibers. None of these
materials possesses rubber elastic properties.
[0012] The preferably multifilament synthetic yarn described in
U.S. Pat. No. 5,927,060 can bear elongation by about 5% without a
change in the electrical conductivity. The textile core thread
employed there possesses no rubber elastic properties whatsoever.
Moreover, the weak wrapping with a mere 200 to 600 turns per meter
allows only a little elongation under the given conditions before
the sheathing wire breaks.
[0013] Also the last-described yarns possess no rubber elastic
properties. Even if they can withstand minor elongations in the
range of 3% to 5% without loss of electrical conductivity,
considerable permanent elongations remain. The last-described yarns
also cannot withstand elongations by more than 10% without a break
or at least without loss of conductivity.
[0014] Thus, there continues to be a need for yarns that, in
addition to electrical conductivity, exhibit high elasticity and
improved elongation properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 depicts an electrically conductive yarn.
DETAILED DESCRIPTION OF THE INVENTIONS
[0016] This is where the present invention applies. The object of
the invention as characterized in the claims is to provide yarns
that are electrically conductive, that can be elongated
considerably, at least briefly, without loss of conductivity, and
that exhibit improved elongation properties.
[0017] As illustrated in FIG. 1, the yarns 1 according to the
present invention are made up of at least one elastic core thread
2, at least one electrically conductive thread 3 that is wound
around the core thread, and at least one binding thread 4 that is
wound around the core thread 2. The extensibility of the entire
electrically conductive yarn is limited by the binding thread 4. A
thread can comprise a strand, cord, filaments of natural or
synthetic material, or multi-strand products such as other
yarns.
[0018] The conductive yarn 1 possesses a number of improved
properties. The yarn 1 exhibits elastic properties across a wide
range of a tensile load. In contrast to the conductive yarns known
from the background art, a tensile overload does not lead to a
decrease in the conductivity of a yarn 1 according to the present
invention. This is achieved through the limiting of the
extensibility of the yarn 1 by the binding thread 4. By limiting
the extensibility through the binding thread 4, it is additionally
achieved that the yarn retains its elastic properties across its
entire load range.
[0019] According to a preferred embodiment of the present
invention, the restoring force of the thread 4 increases
disproportionately above a certain tensile load. The reason for
this disproportionate rise in the restoring force lies in the
binding thread 4. That is to say, above a certain tensile load,
said binding thread can no longer give way to this load by
spreading its helical form to a smaller number of turns per unit of
length of the core thread 2, but rather allows a further extension
only through an elongation in the longitudinal direction. The
transition from an expansion of the helical structure to an
effective extension of the binding thread itself in its lengthwise
direction leads to a strong rise in the restoring force, preventing
a further elongation of the yarn. This disproportionate increase in
the restoring force occurs at a tensile load at which the
electrically conductive thread has not yet broken. The yarn 1 is
thus still conductive.
[0020] The scope of the extensibility of the binding thread 4
depends primarily on the material properties and the number of
turns of the binding thread 4 around the core thread 2. Greater
extensibility is generally achieved through a greater number of
turns. In addition, a higher elongation at break of the material
leads to increased extensibility.
[0021] A material's elongation at break is understood to mean the
elongation of the material through tensile load until it breaks. It
serves to determine the strength of the stressed material. Thus, a
material with a high elongation at break can be stretched by a
large amount before it breaks.
[0022] According to the present invention, the extensibility of the
entire electrically conductive yarn 1 is limited by the binding
thread 4. In order to fulfill this property, the core thread 2,
conductive thread 3 and binding thread 4 are expediently
coordinated with respect to the material and the number of wraps of
conductive thread 3 and binding thread 4 around the core thread 2.
In addition, advantageously, some further parameters known to
persons skilled in the art of yarn manufacturing are adjusted. That
is to say, the extensibility further depends on the force with
which the wrapping of the core thread occurs. Also, the various
thread materials exhibit various coefficients of friction, making
differing expenditures of force necessary in order to shift the
individual threads against each other.
[0023] For persons skilled in the art of yarn manufacturing, such a
selection is no problem. For the selection of suitable materials
and manufacturing parameters, persons skilled in the art will
usually present a certain core thread, wrap it with a thin wire and
then specify the binding thread such that the yarn fulfills the
stipulated properties.
[0024] It should be understood that the number of turns around the
core thread in the resulting yarn is influenced not only by the
number of turns actually executed, but also by the degree to which
the core thread is pre-drawn. The higher the force with which the
core thread is pre-drawn, the more dramatic is the rise in the
number of turns present per unit of length of the core thread after
alleviation of the load on the core thread.
[0025] According to a preferred embodiment of the present
invention, the core thread is composed of a rubber elastic
material. The term "rubber elastic material" shall be understood to
mean that, following deformation of the material and subsequent
load alleviation, the original state of the material reappears.
According to DIN 7724 (February 1972), there are two types of
elasticity, namely energy elasticity (steel elasticity) and entropy
elasticity (rubber elasticity). According to a preferred embodiment
of the present invention, the elastic core thread exhibits an
elongation at break of at least 50%, preferably of at least 100%,
particularly preferably of at least 200%. Very particularly
preferably, the core thread possesses an elongation at break of at
least 300%, especially of at least 400%, and particularly
preferably of at least 500%.
[0026] The elastic core thread(s) is/are responsible for the rubber
elastic properties of the entire yarn unit. The market offers a
variety of rubber elastic threads from which the material suited to
the relevant application can be selected. These include natural and
synthetic rubbers, the various types of polyester and polyether
elastane, modified polyester, post-cross-linked thermoplasts, etc.
Polyester-polyurethane elastomers and/or polyether-polyurethane
elastomers are very particularly suited as materials for the rubber
elastic core thread.
[0027] Following elongation, the yarns according to the present
invention should, due to the rubber elastic properties of the core
thread, recontract to at least almost the original length.
According to a preferred embodiment of the present invention,
following an elastic elongation by at least 15% in the lengthwise
direction, the electrically conductive yarn exhibits a maximum
permanent elongation of 5% without loss of its electrical
conductivity. Particularly preferably, following an elastic
elongation by at least 30% in the lengthwise direction, the
electrically conductive yarn exhibits a maximum permanent
elongation of 5% without loss of its electrical conductivity.
[0028] The core thread can be employed in a form that is suitable
for the relevant application. To cite a few variants by way of
example: monofilament, multifilament, segmented types and textured
types. If required, multiple threads may also be employed in the
core in parallel or twisted. Threads of the same kind or of
different kinds may be employed side by side.
[0029] The elastic core of the composite yarn is furnished with at
least one electrically conductive wrapping. The elastic core can be
wound multiple times with conductive threads. These conductive
wrappings can also be applied in differing wrapping directions and,
if appropriate, they can be separated from one another by
intermediate layers.
[0030] Metallic wires, wire cords or meshes, conductingly coated
synthetic fibers, staple yarns with a metal portion, threads of
conductive polymers and conductively filled synthetic fibers are
especially suitable as conductive threads. The conductive threads
can be employed singly or multiply, from a single grade or mixed.
Monofilament metal wires used as conductive threads exhibit a
diameter between about 0.01 and 0.1 mm, preferably between 0.02 and
0.06 mm, and particularly preferably between 0.03 and 0.05 mm.
[0031] Although, in principle, numerous metals and alloys, which
may additionally be coated, anodized or etched, are suitable as
conductive threads, copper wires, silver-coated copper wires and
stainless steel wires are particularly preferred due to technical
and economic factors. The use of coated or lacquered wire types
improves the corrosion resistance and washability of the yarns
according to the present invention. Not only are such yarns easily
washable, but what is more, they even withstand dry-cleaning.
[0032] In addition to monofilament metal wires, multifilament
stainless steel yarns are excellently suited for manufacturing the
yarns according to the present invention. The thickness of a single
stainless steel filament ranges between 0.002 mm and 0.02 mm. The
number of individual filaments contained lies between 10 and
200.
[0033] The use of silver-coated synthetic yarns for the
electrically conductive wrapping of the elastic core lends itself
to numerous applications. Wash-resistant, silver-coated nylon
threads are particularly suitable for manufacturing the yarns
according to the present invention. The market offers both
monofilament and multifilament yarns. Compared with monofilament
fibers, higher surface coverage of the core can be achieved with
multifilament yarns as the wrapping, with the same yarn
diameter.
[0034] In addition to the electrically conductive wrapping, the
yarn comprises a further wrapping. Such a wrapping can assume
various functions. To cite a few by way of example: electrical
insulation (outwardly, inwardly or between multiple conductive
layers), mechanical abrasion protection, improvement of the working
properties of the yarn on fast-running machines, color, luster,
appearance, handle, surface feel, protection against
overstretching, tensile strength, equalization of the internal
torsional stress of the yarn after wrapping in one direction. It
should be pointed out that this further binding thread will not
usually be electrically conductive. However, the present invention
also covers binding threads that exhibit electrical conductivity of
any magnitude.
[0035] For numerous applications, a yarn construction with
inward-lying elastic core, inner wrapping with conductive thread
and textile outer wrapping executed in the opposite direction
thereto is suitable. The external wrapping is structured such that,
in the event of a strong elongation, it is completely stretched
before the inward-lying conductive wrapping. In this way, the outer
wrapping breakes an elongation before the conductive wrapping is
damaged.
[0036] Further preferred embodiments of the yarn according to the
present invention include the use of multifilament yarns as a
non-conducting wrapping. When wrapping a core, multifilament yarns
preferably arrange themselves laminarly on the core thread, such
that they effect considerably greater surface coverage compared
with a monofilament, with the same external diameter.
[0037] Depending on the application, all kinds of threads can be
suitable for the described further wrapping. To cite some
representatives for the possible materials by way of example:
nylon, polyester, rayon, polyamide, linen, wool, silk, cotton,
polypropylene, kevlar in its various embodiments, blended yarns of
all kinds, and metallized yarns, such as silver-coated nylon.
[0038] The manufacture of the yarns according to the present
invention can occur in various ways. The preferred method is
traditional yarn winding. Here, the central elastic thread is drawn
on drawing equipment. The drawn elastic core thread is passed
through a rotating hollow spindle. On the hollow spindle sits the
bobbin with the conductive thread or the binding thread. This
thread is carried along by the elastic core thread that is taken up
evenly, such that the conductive thread or the binding thread is
wound around the core thread in the form of a spiral. When the
drawn core thread relaxes again after winding, the individual turns
lie substantially closer together than during winding.
[0039] Compared with inelastic yarns, rubber elastic yarns can be
produced with high draft, which, under otherwise identical
production conditions, leads to considerably tighter turns
resulting from the described relaxation of the yarn after winding.
With the cited method, elastic yarns can be wound more tightly than
non-elastic yarns.
[0040] As a basic principle, the winding of the core thread with a
further thread creates internal torsional forces that lead to the
yarn in the relaxed state, that is, when unwinding from the bobbin,
twisting about itself. Winding two threads around the core thread
results in the possibility to eliminate these internal torsional
forces. This is referred to as "equilibration" of the yarn. That is
to say, if the second thread is wound around the core thread in the
opposite direction to the first thread, torsional forces are
yielded in opposing directions. Now, through simple experiments,
the material and number of turns can be coordinated such that the
magnitudes of the torsional forces are approximately equal,
yielding a resulting torsional force of nearly zero. Consequently,
it is ensured that the yarn in the relaxed state twists about
itself very little, if at all.
[0041] Thus, according to a preferred embodiment of the present
invention, the electrically conductive thread and the binding
thread are wrapped in opposite directions around the elastic core
thread. Thus, for example, if the electrically conductive thread is
wound around the elastic core thread in the S-direction, then the
binding thread is wrapped around the elastic core thread in the
Z-direction. It is thus a crosswise wrapping.
[0042] The present invention also comprises the use of the yarns
and fabrics according to the present invention for data transfer
and power supply of electrical and electronic components. In
addition, also comprised is the use of the yarns and fabrics
according to the present invention as electrically conducting
materials that, similar to a ribbon cable or a
local-resolution-activatable two-dimensional matrix, can transport
various electrical signals side by side with no appreciable mutual
interference.
[0043] Furthermore, yarns according to the present invention or
products produced therefrom can be employed for shielding
electromagnetic fields or for dissipating static charges. A use of
the yarns according to the present invention as a heating resistor
in the context of electrical heating is possible.
[0044] The present invention also comprises the use of the yarns
according to the present invention as electrical heat conductors,
and the fabrics produced therewith as elastic, electrically
heatable fabrics.
[0045] The present invention additionally comprises the use of the
yarns according to the present invention as a sensor material,
preferably as a humidity sensor or strain sensor.
Means of Executing the Invention
[0046] In the following, the invention will be explained in greater
detail based on exemplary embodiments, but it is expressly pointed
out that the invention is not intended to be limited to the
specified examples.
EXAMPLE 1
[0047] An elastic thread of LYCRA.RTM. elastane yarn (dtex/type:
1880 dtex, Type T-163C) manufactured by DuPont.RTM. is pre-drawn on
a yarn winding machine. The elongation at break of the thread is
500%, with a tear strength of 1300 cN. After elongation of 100%,
the thread relaxes except for a permanent elongation of 2.4%.
[0048] The pre-drawn LYCRA.RTM. thread is passed through a hollow
spindle. This hollow spindle carries a conical yarn spindle from
which a 0.04 mm thick, hard silver-plated copper wire is drawn off
overend by the LYCRA.RTM. thread. Silver/Copper Textile wire with
TW-D coating manufactured by Elektro-Feindraht AG may be used. The
diameter of this wire including its lacquer coating measures about
0.048 mm. The wire also exhibits an elongation at break of
21.3%.
[0049] The single-wire-enwound LYCRA.RTM. is passed through a
second hollow spindle. This hollow spindle carries a commercially
available multifilament polyamide (PA) yarn of PA66 with 78 dtex
and 34 individual filaments. PA66 multifilament polyamide yarn
having a product designation of RN01235 78/34/1S and manufactured
by Radicifil S.p.A./Synfil GmbH with elongation at break of 28% may
be used. The PA66 yarn is wrapped around the core counter to the
wire. The machine parameters are selected such that an equilibrated
yarn is created that is as free as possible from internal torsional
stress.
[0050] The outer PA66 yarn is wound around the core 3200 times per
meter of yarn; the inner wire is wound around the core 3600 times
per meter of yarn. The inward-lying wire is nearly completely
covered by the outward-lying PA66 yarn, so that the yarn possesses
a textile appearance and surface feel. The yarn possesses excellent
electrical conductivity. If elongated by approximately 250%, the
restoring force of the yarn becomes disproportionately stronger
through complete extension of the PA66 yarn. Only when elongated
approximately 300% does the yarn lose its electrical conductivity
due to wire break.
EXAMPLE 2
[0051] The elastic, electrically conducting composite yarn in
example 1 is employed as the weft thread on a commercially
available power loom. The warp beam is composed of 0.3 mm thick,
single-twisted cotton threads combined in groups of 8 threads. When
interwoven, a firm fabric is created that possesses excellent
electrical conductivity in the weft direction, and that does not
conduct the electric current in the direction of the warp. These
electrical properties are retained even after elongation by more
than 120% in the weft direction. If the poles of a direct current
voltage source are connected, spaced apart in the warp direction,
this voltage can be used, at a distance of one meter in the weft
direction, to operate an electrical sink, such as a light-emitting
diode. The fabric can be stretched in the weft direction with no
impact on the power supply of the light-emitting diode.
EXAMPLE 3
[0052] The elastic, electrically conducting composite yarn in
example 1 is employed as the weft thread on a commercially
available power loom. The warp beam is composed of an electrically
conducting but not rubber elastic composite yarn. To manufacture
the warp thread, a commercially available polyester yarn with 100
dtex and 36 individual filaments is furnished with an inner
wrapping of 0.041 mm thick, hard silver-plated copper wire and an
outer wrapping of commercially available polyamide yarn (PA66) with
78 dtex and 34 individual filaments.
[0053] When interwoven, a firm fabric is created that possesses
excellent electrical conductivity in the weft direction and an
electrical conductivity in the direction of the warp thread
independent from the one in the weft direction. These electrical
properties are retained even after elongation by more than 120% in
the weft direction. This fabric, which is economical to produce,
can, with suitable electronic activation, be employed as a matrix
for spatially resolving signal capture, or for operating a
spatially resolving output unit, such as a monitor.
EXAMPLE 4
[0054] An elastic thread of LYCRA.RTM. 163C by DuPont with 1880
dtex is pre-drawn on a yarn winding machine. The pre-drawn elastic
thread is passed through a hollow spindle. This hollow spindle
carries a conical yarn spindle from which a conductive thread
comprising silver-coated polyamide thread with 30 denier and 18
individual filaments (X-static, Life SRL, I-25015 Desenzano, Italy)
is drawn off overend by the elastic thread. In this example,
X-static.RTM. (a silver-coated fiber) manufactured by Life SRL is
used. The elastic, single-enwound with the silver-coated fibers, is
passed through a second hollow spindle. This hollow spindle carries
a commercially available multifilament polyamide yarn of PA66 with
33 dtex and 10 individual filaments. The PA66 yarn is wrapped
around the core counter to the silver-coated fibers. The machine
parameters are selected such that an equilibrated yarn is created
that is as free as possible from internal torsional stress. The
outer PA66 yarn is wound around the core 3200 times per meter of
yarn; the silver-coated thread is wound around the core 3600 times
per meter of yarn. The inward-lying silver-coated thread is not
completely covered by the outward-lying PA66 yarn. The yarn
possesses excellent electrical conductivity. If elongated by
approximately 250%, the restoring force of the yarn becomes
disproportionately stronger through the complete extension of the
PA66 yarn. Only when elongated approximately 320% do the yarns
sheathing the LYCRA.RTM. core break.
EXAMPLE 5
[0055] The elastic, electrically conducting composite yarn in
example 4 is employed as the weft thread on a commercially
available power loom. The warp beam is comprised of an electrically
conducting but not rubber elastic composite yarn. To manufacture
the warp thread, a commercially available polyester yarn with 100
dtex and 36 individual filaments is furnished with an inner
wrapping of a silver-coated polyamide thread with 30 denier and 18
individual filaments (X-static.RTM. by Life SRL) and an external
wrapping of commercially available polyamide yarn (PA66) with 33
dtex and 10 individual filaments.
[0056] When interwoven, a firm fabric is created that possesses
excellent electrical conductivity. Due to the non-complete
insulation of the silver-coated wrappings in both the warp and the
weft thread, all electrically conducting yarns in the fabric are in
electrical contact with one another. This direction-independent
electrical conductivity is retained even after elongation by more
than 100% in the weft direction. Such a fabric possesses excellent
shielding properties against electromagnetic radiation, especially
in the range of 1 to 2000 MHz.
EXAMPLE 6
[0057] The elastic, electrically conducting composite thread in
example 1 is employed as the warp thread on a commercially
available ribbon weaver. The warp beam is alternately composed of
sequences of 8 identical threads each. The alternation occurs
between bundles of eight of the yarns described in example 1 and
yarns without a conductive portion. The threads without a
conductive portion correspond largely completely to the yarns
described in example 1 except for the fact that, instead of the
wire, a multifilament polyamide yarn of PA66 with 78 dtex and 34
individual filaments is employed. A commercially available
multifilament polyamide yarn is employed as the weft thread.
[0058] The elastic ribbon manufactured in this way possesses
coexisting conducting ribbons that are electrically insulated from
one another. In order to preclude short circuits between the
conducting ribbons even in damp environments, it is advantageous to
use a plastic-coated wire to manufacture the yarn. A flat elastic
cable described in this example is outstandingly suited to
connecting electrical and electronic components in clothing. The
ribbon can be extended in the warp direction without loss of
electrical conductivity. The ribbon is not sensitive to the creases
and folds that occur when clothing is worn.
EXAMPLE 7
[0059] The elastic, in weft direction electrically conducting
fabric in example 2 is electrically contacted in the weft direction
by means of commercially available flat cable connectors at a width
of 1.1 cm and a length of 50 cm. After a direct current voltage is
applied, electric current flows. Midway between the connection
points, the temperature increase resulting from the current flow is
determined by means of an NTC resistance. At a heat output of 5 W
(1.4 A at 3.6 V), the temperature increase achieved measures
30.degree. C. At a heat flow of 13 W (2 A at 6.5 V), the
temperature increase measures 64.5.degree. C.
[0060] The extensibility and the textile surface feel of the fabric
makes it highly suitable for manufacturing elastic, electrically
heatable textiles that come into direct contact with the body.
Examples of applications include socks, joint warmers, back
warmers, gloves, elastic bandages, etc.
[0061] Thus, while the preferred embodiments of the devices and
methods have been described in reference to the environment in
which they were developed, they are merely illustrative of the
principles of the inventions. Other embodiments and configurations
may be devised without departing from the spirit of the inventions
and the scope of the appended claims.
* * * * *