WO2004027132A1 - Electrically conductive thread - Google Patents

Abstract

The invention relates to electrically conductive thread. Said thread comprises 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 and is non-electrically conductive. The extensibility of the entire electrically conductive thread is restricted by the binding thread.

Description

 Electrically conductive

Technical field

The present invention relates to elastic, electrically conductive yarns, their use and methods for their production.

State of the art

Some methods for producing electrically conductive yarns are known. So z. B. for the discharge of electrostatic charge for a long time metal wires or wire mesh or metallized yarn incorporated directly into the fabric. These fabrics are often problematic to manufacture on the loom and, due to the exposed wires, have a limited textile appearance and / or a metallic handle.

Methods for producing so-called staple yarns are also known. Essentially short textile fibers are spun into a yarn together with short and very fine metal fibers. Depending on the metal content, these yarns have more or less textile or metallic properties. Stacking yarns with good electrical conductivity have a metallic look and feel.

Methods are also known in which centrally guided metal wires are wrapped in single or double textiles. Since it is essentially the wire that determines the tensile strength in these yarns, relatively thick wires with diameters greater than 0.1 mm are usually used. Such yarns are relatively stiff and therefore unusable for textile applications.

EP 250 260 describes how thin wires in the core of a wound yarn are also covered by wrapping parallel wire and textile thread can be used. In this arrangement, the central textile thread ensures tear resistance, while the thin wire running in parallel ensures the electrical conductivity of the yarn. However, such yarns are not particularly stretchable.

CH 690 686 describes the production of a composite yarn from a textile fuse and monofilament metal thread. During the yarn spinning process on a ring spinning machine, the fuse is fed a coated metal wire centrally. In the thermal treatment following the spinning process, the melting coating glues the central wire to the spun textile covering. These yarns also do not have good ductility.

None of the yarns described above can be elastically stretched to a significant extent without loss of electrical conductivity, since the conductive threads either tear or plastically deform.

The documents US 4,776,160, US 5,881,547 and US 5,927,060 each describe yarns in which electrically conductive threads are wound around centrally arranged textile threads. In principle, this arrangement allows the entire yarn unit to be stretched to a certain extent without causing the yarn to tear or the conductive wrap to break.

US 5 881 547 teaches the manufacture of a highly tear-resistant, electrically conductive yarn for use in fencing clothing. These yarns consist of a non-electrically conductive core thread and a double, cross wrap with stainless steel wire. Due to the large diameter of the stainless steel wires used, they are very stiff in the range between 0.6 mm and 1.2 mm, hardly stretchable and in no way elastic.

Both US 4,776,160 and US 5,927,060 mention the use of flexible, stretchable core threads for the production of conductive yarns with good textile properties. US 4,776,160 mentions as materials for the core thread thermoplastics such as. B. nylon, polyester, rayon, acrylic, PEEK, PBS, PBI, polyolefins (PE, PP) and liquid crystalline polymers, polycarbonate, polyvinyl alcohol and aramid fibers. None of these materials has rubber-elastic properties.

The preferably multifilament synthetic yarn described in US Pat. No. 5,927,060 can withstand an elongation of approximately 5% without changing the electrical conductivity. The textile core thread used there has no rubber-elastic properties. In addition, the weak winding with only 200 to 600 turns per meter allows only a small amount of stretch under the given conditions until the wrapping wire breaks.

The yarns described last also have no rubber-elastic properties. Even if they can withstand small strains in the range of 3% to 5% without loss of electrical conductivity, significant residual strains remain. The yarns described last cannot survive elongations of more than 10% without tearing off or at least without loss of conductivity.

There is therefore still a need for yarns which, in addition to having electrical conductivity, have high elasticity and improved elongation properties.

Presentation of the invention

This is where the invention comes in. The object of the invention, as characterized in the claims, is to provide yarns which are electrically conductive, which can be significantly stretched at least for a short time without loss of conductivity and which have improved elongation properties.

This object is achieved by the yarn according to claim 1. Further advantageous details, aspects and configurations of the present invention result from the dependent claims, the description and the examples. The yarns according to the invention are made up of at least one elastic core thread, at least one electrically conductive thread wound around the core thread and at least one winding thread wound around the core thread. The elasticity of the entire electrically conductive yarn is limited by the winding thread.

Such a conductive yarn has a number of improved properties. The yarn has elastic properties over a wide range of tensile stress. In contrast to the conductive yarns known from the prior art, an overload due to tensile stress does not lead to a reduction in the conductivity of a yarn according to the invention. This is achieved by limiting the stretchability of the yarn by the thread. Limiting the elasticity of the wrapping thread also ensures that the yarn retains its elastic properties over its entire load range.

According to a preferred embodiment of the present invention, the restoring force of the yarn increases disproportionately from a certain tensile load. The reason for this disproportionate increase in the restoring force lies in the thread. This is because from a certain tensile load this load can no longer yield to a smaller number of turns per unit length of the core thread by spreading its helical shape, but allows further stretching only by stretching in the longitudinal direction. The transition from an expansion of the helical structure to an actual stretching of the wrapping thread even in its longitudinal direction leads to a strong increase in the restoring force, which prevents further stretching of the yarn. This disproportionate increase in the restoring force takes place in the event of a tensile load in which the electrically conductive thread has not yet broken. So the yarn is still conductive.

The degree of stretchability of the wrapping thread depends mainly on the material properties and the number of wraps of the wrapping thread around the core thread. A higher number of windings will generally achieved a higher elasticity. In addition, a higher elongation at break of the material leads to increased elasticity.

The elongation at break of a material is the elongation of the material due to tensile stress until it breaks. It is used to determine the strength of the stressed material. A material with a high elongation at break can therefore be stretched by a large amount before it breaks or breaks in the case of threads.

According to the invention, the extensibility of the entire electrically conductive yarn is limited by the winding thread. In order to fulfill this property, core thread, conductive thread and wrapping thread are expediently coordinated with one another with regard to material and with regard to the number of wraps of conductive thread and wrapping thread around the core thread. In addition, several other parameters known to those skilled in the field of yarn production are advantageously adapted. The elasticity also depends on the force with which the core thread is wound. The different thread materials also have different coefficients of friction, which means that a different amount of force is required in order to shift the individual threads against one another.

Such a selection is not a problem for the person skilled in the field of yarn production. For the selection of suitable materials and suitable production parameters, the person skilled in the art will usually present a specific core thread, wrap it with a thin wire and then determine the winding thread in such a way that the yarn has the desired length required properties met.

It should be noted that the number of turns around the core thread which are present in the resulting yarn is influenced not only by the number of windings actually carried out, but also by the degree of pre-stretching of the core thread. The higher the force with which the core thread is pre-stretched, the more drastically increases the number of turns that are present per unit length of the core thread after the core thread is relieved. According to a preferred embodiment of the present invention, the core thread consists of a rubber-elastic material. The term "rubber-elastic material" means that after deformation of the material and subsequent relief, the original state of the material is restored. According to DIN 7724 (February 1972), a distinction is made between 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 has an elongation at break of at least 50%, preferably at least 100%, particularly preferably at least 200%. The core thread very particularly preferably has an elongation at break of at least 300%, in particular at least 400%, particularly preferably at least 500%.

The elastic core thread or threads 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 suitable for the respective application can be selected. These include natural and synthetic rubbers, the various types of polyester and polyether elastane, modified polyesters, post-crosslinked thermoplastics etc. Polyester-polyurethane elastomers and / or polyether-polyurethane elastomers are particularly suitable as materials for the rubber-elastic core thread.

After stretching, the yarns according to the invention should contract at least approximately again to the original length due to the rubber-elastic properties of the core thread. According to a preferred embodiment of the present invention, after elastic stretching by at least 15% in the longitudinal direction, the electrically conductive yarn has a maximum residual elongation of 5% without losing its electrical conductivity. Particularly preferably, after elastic stretching by at least 30% in the longitudinal direction without loss of its electrical conductivity, the electrically conductive yarn has a maximum residual elongation of 5%. The core thread can be used in a form suitable for the respective application. Some variants are mentioned as examples: monofilament, multifilament, segmented types and textured types. If necessary, several threads can be used in parallel or twisted in the core. Similar or different threads can be used side by side.

The elastic core of the composite yarn is equipped with at least one electrically conductive wrap. The elastic core can be wound several times with conductive threads. These conductive wraps can also be applied in different winding directions and optionally separated from one another by intermediate layers.

Particularly suitable as conductive threads are metallic wires, wire threads or braids, conductively coated synthetic fibers, staple yarns with metal content, yarns made of conductive polymers and conductive filled synthetic fibers. The conductive threads can be used one or more times, single or mixed. Monofilament metal wires used as conductive threads have a diameter between 0.01 and 0.1 mm, preferably between 0.02 and 0.06 mm, particularly preferably between 0.03 and 0.05 mm.

Although in principle numerous metals and alloys, which can additionally be coated, anodized or pickled, 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 coated wire types improves the corrosion resistance and washability of the game according to the invention. Such games are not only washable, they actually resist chemical cleaning.

In addition to monofilament metal wires, multifilament stainless steel yarns are extremely suitable for producing the yarns according to the invention. Typically, the thickness of a single stainless steel filament ranges between 0.002 mm and 0.02 mm. The number of individual filaments contained is between 10 and 200. The use of silver-coated synthetic yarns for electrically conductive wrapping around the elastic core is suitable for numerous applications. Wash-resistant, silver-coated nylon yarns are particularly suitable for producing the yarns according to the invention. The market offers both monofilament and multifilament games. With multifilament threads as a wrap, higher surface coverage of the core can be achieved with the same yarn diameter compared to monofilament fibers.

In addition to the electrically conductive wrap, the yarn includes another wrap. Such a winding can perform various functions. Examples include: electrical insulation (outside, inside or between several conductive layers), mechanical abrasion protection, improvement of the processability of the yarn on high-speed machines, color, gloss, optics, handle, haptics, over-stretch protection, tear resistance, compensation of the internal torsional tension of the yarn after winding in one direction. It should be pointed out that this further winding thread will generally not be electrically conductive. However, the present invention also encompasses wrapping threads that have an electrical conductivity of any strength.

A yarn structure with an internal elastic core, inner wrapping with conductive thread and a textile outer wrapping in the opposite direction is suitable for numerous applications. The outer wrapping is designed so that it is fully tensioned in the event of a strong stretch in front of the inner conductive wrapping. The outer wrap slows down stretching before the conductive wrap is damaged.

Further preferred embodiments of the yarn according to the invention include the use of multifilament yarns as a non-conductive wrap. When wrapping around a core, multifilament games prefer to lie flat on the core thread, so that with the same outer diameter they provide a significantly higher surface coverage compared to the monofilament. Depending on the application, all possible threads can be suitable for the further winding described. Representative of the possible materials may be mentioned as examples: nylon, polyester, viscose, polyamide, linen, wool, silk, cotton, polypropylene, Kevlar in the various embodiments, mixed yarns of all types and metallized game such as. B. silver coated nylon.

The yarns according to the invention can be produced in various ways. The method of classic yarn winding is preferred. The central elastic thread is warped on a drafting system. The warped elastic core thread is passed through a rotating hollow spindle. The spool of thread with the conductive thread or the winding thread sits on the hollow spindle. This thread is carried along by the uniformly drawn-off elastic core thread, so that the conductive thread or the winding thread is wound in the form of a helix around the core thread. If the warped core thread relaxes again after winding, the individual wraps are much denser than during wrapping.

Rubber-elastic yarns can be manufactured with a high warp compared to inelastic yarns, which leads to significantly narrower windings under otherwise identical production conditions due to the relaxation of the yarn after winding. Elastic yarns can be wrapped more tightly than non-elastic yarns using the method mentioned.

Basically, by winding the core thread with another thread, there are internal torsional forces that cause the thread to twist around itself in the unloaded state, i.e. when unwinding from the bobbin. If two threads are wound around the core thread, there is the possibility of eliminating these internal torsional forces. In this case one speaks of a "balancing" of the yarn. If the second thread is wound around the core thread in the opposite direction to the first thread, torsional forces result in opposite directions. The material and the number of turns can now be coordinated with one another by simple tests that the amounts of the torsional forces are approximately the same and that a resulting torsional force of results in almost zero. As a result, it is ensured that the yarn twists itself or not at all in the unloaded state.

According to a preferred embodiment of the present invention, the electrically conductive thread and the wrapping thread are wound in opposite directions around the elastic core thread. If, for example, the electrically conductive thread is wound around elastic core thread in the S direction, the wrapping thread is wound around the elastic core thread in the Z direction. So it is a cross-wrap.

The present invention also includes the use of the yarns and fabrics according to the invention for data transmission and the power supply of electrical or electronic components. In addition, the use of the yarns and fabrics according to the invention as electrically conductive materials is also included, which, like a ribbon cable or a two-dimensional matrix that can be controlled in a spatially resolved manner, can transport different electrical signals next to one another without any appreciable mutual influence.

Furthermore, yarns according to the invention or products made therefrom can be used to shield electromagnetic fields or to discharge static charges. It is possible to use the yarns according to the invention as a resistance conductor in the context of an electrical heater.

The present invention also includes the use of the yarns according to the invention as an electrical heating conductor and the fabric made therefrom as an elastic, electrically heatable fabric.

The present invention also includes the use of the yarns according to the invention as a sensor material, preferably as a moisture sensor or strain sensor. Ways of Carrying Out the Invention

The invention is to be explained in more detail below on the basis of exemplary embodiments, but it is expressly pointed out that the invention is not intended to be limited to the examples given.

Example 1:

An elastic thread made of Lycra 163C (manufacturer: Du pont De Nemours International SA Fibers Department, Du Pont Straße 1, D-61352, Bad Homburg; product name: LYCRA Elastane Yarn; Dtex / type: 1880 Dtex T. 136C) with a thickness of 1880 dtex is pre-stretched on a yarn winding machine. The elongation at break of the thread is 500% with a tensile strength of 1300 cN. After a stretch of 100%, the thread relaxes to a residual stretch of 2.4%.

The pre-stretched Lycra thread is passed through a hollow spindle. This hollow spindle carries a conical thread spindle, from which a 0.04 mm thick, hard silver-plated copper wire (manufacturer: Elektro-Feindraht AG in CH-8182 Escholzmatt; product name: Textile Wire silver / copper with varnish type TW-D) is drawn off by the lycra thread becomes. The diameter of the wire including its coating is 0.048 mm. The wire has an elongation at break of 21.3%.

The Lycra, which is simply wrapped in wire, is guided through a second hollow spindle. This hollow spindle carries a commercially available multifilament polyamide yarn made of PA66 with 78 dtex and 34 individual filaments (manufacturer: Radicifil S.p.A. / Synfil GmbH, IT-24126 Bergamo; designation RN01235_78 / 34 / 1S; elongation at break: 28%). The PA66 yarn is wound around the core in the opposite direction to the wire. The machine parameters are selected so that a balanced yarn is created that is as free as possible from internal torsional stresses.

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 inside lying wire is almost completely covered by the outside PA66 yarn, so that the yarn has a textile look and feel. The yarn has excellent electrical conductivity. With a stretch of approx. 250%, the restoring force of the yarn becomes disproportionately stronger when the PA66 yarn is fully stretched. The yarn only loses its electrical conductivity due to wire breakage after approx. 300% elongation.

Example 2:

The elastic, electrically conductive composite yarn from Example 1 is used as a weft thread on a commercially available weaving machine. The warp beam consists of 0.3 mm thick, simply twisted cotton threads, which are combined in groups of 8 threads. When weaving, a firm fabric is created which has excellent electrical conductivity in the weft direction and does not conduct the electrical current in the direction of the warp thread. These electrical properties are retained even after stretching by more than 120% in the weft direction. If the poles of a DC voltage source are connected at a distance in the warp thread direction, this voltage can be spaced one meter apart in the weft thread direction for operating an electrical consumer, such as, for. B. a light emitting diode can be used. The fabric can be stretched in the weft direction without affecting the power supply to the light emitting diode.

Example 3:

The elastic, electrically conductive composite yarn from Example 1 is used as a weft thread on a commercially available weaving machine. The warp beam consists of an electrically conductive, but not rubber-elastic composite yarn. To produce the warp thread, a commercially available polyester yarn with 100 dtex and 36 individual filaments is equipped with an inner winding made of 0.041 mm thick, hard silver-plated copper wire and an outer winding made of commercially available polyamide yarn (PA66) with 78 dtex and 34 individual filaments. Weaving creates a strong fabric that has excellent electrical conductivity in the weft direction and an independent electrical conductivity in the direction of the warp thread. These electrical properties are retained even after stretching by more than 120% in the weft direction. This fabric, which is inexpensive to manufacture, can be used with a corresponding electronic control as a matrix for spatially resolving signal acquisition or for operating a spatially resolving output unit such as, for. B. a screen can be used.

Example 4:

An elastic thread made of Lycra 163C (Du Pont de Nemours GmbH, Du Pont Straße 1, D-61352, Bad Homburg) with 1880 dtex is pre-stretched on a yarn winding machine. The pre-stretched Lycra thread is passed through a hollow spindle. This hollow spindle carries a conical thread spindle, from which a silver-coated polyamide thread with 30 denier and 18 individual filaments (X-static, Life SRL, 1-25015 Desenzano, Italy) is pulled off through the lycra thread. The Lycra, simply wrapped with the silver-coated fiber, is guided through a second hollow spindle. This hollow spindle carries a commercially available multifilament polyamide yarn made of PA66 with 33 dtex and 10 individual filaments. The PA66 yarn is wound around the core in the opposite direction to the silver-coated fiber. The machine parameters are selected so that a balanced yarn is created that is as free as possible from internal torsional stresses. 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 inside silver-coated thread is not completely covered by the outside PA66 yarn. The yarn has excellent electrical conductivity. With a stretch of approx. 250%, the restoring force of the yarn becomes disproportionately stronger when the PA66 yarn is fully stretched. The yarns that envelop the Lycra core only tear at about 320% elongation. Example 5:

The elastic, electrically conductive composite yarn from Example 4 is used as a weft thread on a commercially available weaving machine. The warp beam consists of an electrically conductive, but not rubber-elastic composite yarn. To produce the warp thread, a commercially available polyester yarn with 100 dtex and 36 individual filaments with an inner winding is made of a silver-coated polyamide thread with 30 denier and 18 individual filaments (X-static, Life SRL, 1-25015 Desenzano, Italy) and an outer winding commercial polyamide yarn (PA66) with 33 dtex and 10 single filaments.

Weaving creates a strong fabric that has excellent electrical conductivity. Due to the incomplete insulation of the silver-coated wraps in both the warp and weft threads, all electrically conductive yarns in the fabric are in electrical contact with one another. This direction-independent electrical conductivity is retained even after stretching by more than 100% in the weft direction. Such a fabric has excellent shielding properties against electromagnetic radiation, in particular in the range from 1 to 2000 MHz.

Example 6:

The elastic, electrically conductive composite yarn from Example 1 is used as a warp thread on a commercially available ribbon loom. The warp beam consists of sequences of 8 identical threads each. It is alternated between bundles of eight from the yarns described in Example 1 and those without a conductive portion. The threads without a conductive portion largely correspond to the yarns described in Example 1, except for the fact that a multifilament polyamide yarn made of PA66 with 78 dtex and 34 individual filaments is used instead of the wire. A commercially available multifilament polyamide yarn is used as the weft thread. The elastic band produced in this way has conductive strips which are present next to one another and are electrically insulated from one another. In order to rule out short circuits between the conductive tapes even in a damp environment, the use of a plastic-coated wire for the production of the yarn is advantageous. An elastic flat cable described in this example is ideal for connecting electrical or electronic components in clothing. The tape can be stretched in the warp direction without loss of electrical conductivity. The tape is not sensitive to the creases and folds that occur when wearing clothing.

Example 7:

The elastic fabric which is electrically conductive in the weft direction from Example 2 is electrically contacted in the weft direction to a width of 1.1 cm and a length of 50 cm by means of commercially available ribbon cable plugs. After applying a DC voltage, electrical current flows. In the middle between the connection points, the temperature increase resulting from the current flow is determined using an NTC resistor. With a heating power of 5 W (1.4 A at 3.6 V), the temperature increase reached is already 30 ° C. With a heating current of 13 W (2 A at 6.5 V) the temperature increase is 64.5 ° C.

The stretchability and the textile feel of the fabric make it ideal for the production of elastic, electrically heatable textiles that are in direct contact with the body. Examples of applications are socks, joint warmers, back warmers, gloves, elastic bandages etc.

Claims

claims 1. An electrically conductive yarn comprising at least one elastic core thread, at least one electrically conductive thread wound around the core thread and at least one thread wound around the core thread Wrapping thread, characterized in that the extensibility of the entire electrically conductive yarn is limited by the wrapping thread. 2. Electrically conductive yarn according to claim 1, characterized in that the wrapping thread causes a disproportionate increase in the restoring force of the electrically conductive yarn from a certain tensile stress, the disproportionate increase in the restoring force occurring before the loss of the conductivity of the yarn. 3. Electrically conductive yarn according to claim 1 or 2, characterized in that the core thread consists of a rubber-elastic material. 4. Electrically conductive yarn according to at least one of claims 1 to 3, characterized in that the elastic core thread has an elongation at break of at least 50%, preferably at least 100%, particularly preferably at least 200%. 5. Electrically conductive yarn according to claim 4, characterized in that the core thread has an elongation at break of at least 300%, preferably of at least 400%, particularly preferably of at least 500%. 6. Electrically conductive yarn according to at least one of claims 1 to 5, characterized in that the rubber-elastic core thread consists of natural rubber, synthetic rubber, polyester-elastane, polyether-elastane, modified polyester and / or post-crosslinked thermoplastic. 7. Electrically conductive yarn according to claim 6, characterized in that the rubber-elastic core thread consists of polyester-polyurethane elastomer and / or polyether-polyurethane elastomer. 8. Electrically conductive yarn according to at least one of claims 1 to 7, characterized in that the yarn has a maximum residual elongation of 5% without loss of electrical conductivity after elastic stretching by at least 15% in the longitudinal direction. 9. Electrically conductive yarn according to at least one of claims 1 to 8, characterized in that the yarn has a maximum residual elongation of 5% without loss of electrical conductivity after elastic stretching by at least 30% in the longitudinal direction. 10. Electrically conductive yarn according to at least one of claims 1 to 9, characterized in that a monofilament metal wire with a diameter between 0.01 and 0.1 mm, preferably between 0.02 and 0.06 mm, particularly as the electrically conductive thread preferably between 0.03 and 0.05 mm is used. 11. Electrically conductive yarn according to at least one of claims 1 to 10, characterized in that a metallically coated synthetic fiber is used as the electrically conductive thread. 12. Electrically conductive yarn according to claim 11, characterized in that monofilament silver-coated fibers are used as the electrically conductive thread. 13. Electrically conductive yarn according to at least one of claims 1 to 11, characterized in that a metallic multifilament yarn is used as the electrically conductive thread. 14. Electrically conductive yarn according to claim 13, characterized in that a silver-coated multifilament yarn is used as the electrically conductive thread. 15. Electrically conductive yarn according to at least one of claims 1 to 10, characterized in that stainless steel fibers are used as the electrically conductive thread. 16. Electrically conductive yarn according to at least one of claims 1 to 15, characterized in that the wrapping thread is wound on the outside around the core thread wound with an electrically conductive thread. 17. Electrically conductive yarn according to at least one of claims 1 to 15, characterized in that the electrically conductive thread is wound on the outside around the core thread wound with a winding thread. 18. Electrically conductive yarn according to at least one of claims 1 to 17, characterized in that the electrically conductive thread per meter of yarn is wound around the elastic core thread at least 1000 times, preferably at least 2000 times, particularly preferably at least 3000 times. 19. Electrically conductive yarn according to at least one of claims 1 to 18, characterized in that the winding thread per meter of yarn at least 1000 times, preferably at least 2000 times, particularly preferably at least Is wrapped 3000 times around the elastic core thread. 20. Electrically conductive yarn according to at least one of claims 1 to 19, characterized in that the electrically conductive thread and the winding thread are wound in opposite directions around the elastic core thread. 21. A method for producing an electrically conductive yarn according to claims 1 to 20 comprising the steps a) mechanical warping of the elastic core thread on a drafting device, b) guiding the warped core thread through a hollow spindle carrying the electrically conductive thread and rotating about the longitudinal axis, and c ) Passing the warped core thread, which is already simply wrapped with an electrically conductive thread, through a winding thread load-bearing and rotating about the longitudinal axis second hollow spindle, wherein this second hollow spindle rotates in the opposite direction to the first hollow spindle. 22. A fabric comprising at least one electrically conductive yarn according to claims 1 to 20 or an electrically conductive yarn produced according to claim 21. 23. Use of an electrically conductive yarn as defined in claims 1 to 20 or an electrically conductive yarn produced according to claim 21 for the transmission of electrical signals. 24. Use according to claim 23, wherein the electrical signals are analog and / or digital signals. 25. Use of an electrically conductive yarn as defined in claims 1 to 20 or an electrically conductive yarn produced according to claim 21 for supplying electrical or electronic units with electrical current. 26. Use of an electrically conductive yarn as defined in claims 1 to 20 or an electrically conductive yarn produced according to claim 21 for generating heat with electric current. 27. Use of an electrically conductive yarn as defined in claims 1 to 20 or an electrically conductive produced according to claim 21 Yarns for shielding electromagnetic fields. 28. Use of an electrically conductive yarn as defined in claims 1 to 20 or an electrically conductive yarn produced according to claim 21 for dissipating static charges. 29. Use of an electrically conductive yarn as defined in claims 1 to 20 or an electrically conductive yarn produced according to claim 21 as the sensor material, preferably moisture sensor or strain sensor.