EP3126556B1 - Conductive textile yarn, method for producing such a yarn and fabric incorporating such a yarn - Google Patents

Description

Technical area

The invention relates to the field of the textile industry, and more particularly to the manufacture of textiles incorporating conductive yarns having elastic properties. It relates more particularly to an elastic yarn whose constitution allows it not only to have high elasticity properties, combined with electrical properties of high conductivity, and with significant resistance to mechanical and chemical attack.

Such a yarn and the fabric that incorporates it find a particular application for the realization of instrumented clothing.

Previous techniques

In general, there is known the existence of instrumented clothing, that is to say clothing including sensors capable of generating electrical signals representative of the use or physicochemical properties of its user. The manufacture of such garments requires the integration into the garment of yarns with conductive properties of electricity.

Multiple solutions have already been proposed consisting in integrating into a textile substantially conductive son.

The integration or association with the textile is generally done by adding operations after the manufacture of the textile, by embroidery or sewing techniques. It is conceivable that such operations, which are part of the clothing industry, greatly increase the cost price of the garment, since they must be made after the garment has been made.

In addition, and especially, the substantially conductive son are not known to have high elasticity, so they must generally be integrated in a configuration with convolutions to deform at the same time as the textile that supports it.

For example, the textiles described in document EP 2,505,090 .

The Applicant has proposed in the document FR 2 869 047 a wire which has conduction properties of electricity, and which has a relatively high elongation rate at the same time.

More specifically, such a yarn is a gimped yarn, whose core is essentially elastic, typically based on elastane, and whose yarn is a synthetic yarn which is covered with a metal layer, which can be deposited by example by galvanizing.

Such a wire, if it has certain advantages, however, has certain drawbacks when it must be integrated into a textile, and in particular a garment intended to undergo washing operations. Indeed, the strength of the metal coating on the yarn may not be sufficient, and the electrical properties tend to degrade as chemical attacks and abrasion observed during washing operations.

Moreover, the conductivity of such a yarn is relatively dependent on its elongation rate, since it depends on the contact level of the turns of the yarn.

The document JP-A-2011 074538 discloses a wire having electrically conductive properties which comprises an elastic core wire and a wrapping wire formed of an elementary wire, wherein the elementary wire is formed of a carbon fiber wire cored by a synthetic thread. The document WO-2014/014290 discloses an elastic yarn with a wrapping yarn which is formed of a core yarn wrapped with a wire.

Presentation of the invention

There is therefore a need for a wire which has electrical resistance properties which are relatively constant with the elongation rate, and which are as persistent as possible during the washing operations, and more generally of all the operations. which mechanically and / or chemically request the conductive wire.

To do this, it is therefore proposed an elastic textile thread, which is characterized in that it is formed by the assembly of a plurality of parallel intermediate son, assembled by a synthetic binding yarn. Each intermediate wire comprises an elastic core wire and a wrapping wire formed of an elementary wire. This elementary wire is itself formed of a metal core wire, covered with a synthetic wire wrapping. In other words, the invention consists in producing a wire which comprises a continuous conductor formed of a wire, which is protected by a wrapping wire limiting the effects of abrasion and decreasing the surface exposed to chemical attack.

This elementary wire with conductive core is used as a wrapping wire on a substantially elastic core, so that the elongation of this elastic core causes the deformation of the wire which draws a helix whose pitch increases with the elongation of the core. 'soul.

Advantageously in practice, the synthetic wire covering the elementary wire, which covers the wire may be wound contiguous turns. In this configuration, the protection of the wire is improved, since the apparent surface thereof is extremely low, if not zero.

In parallel, the winding of this protective covering yarn makes it possible to limit the risk of deformation of the wire, which is thus blocked in its evolutions. In particular, it limits the risk of the wire twisting so that it loops on itself, and becomes weakened or even cut.

The structure thus described can be declined with different types of materials for each of these constituents. Thus, the wire core wire of the elementary wire may be based on one or more materials selected from the group consisting of copper, steel, silver, or gold. This wire may advantageously be isolated by an enameling or a layer of varnish.

The wrapping thread of the elementary wire, wound around the wire may be made generally from many thermoplastic polymers, and in particular based on son selected from the group comprising polyamides, polyesters or polypropylenes.

Similarly, the core wire of the intermediate wire, which has the elastic properties, may be preferably based on a monotoron, typically made of elastane or equivalent material based elastomeric or other elastic polymers.

Such a structure has the advantage of having an elongation which can be at least 200%, while maintaining a resistivity of less than 1 Ohm.cm.

Such a yarn may be incorporated into a warp and / or weft in a fabric. In the particular application where this wire is used to convey the information from one zone to the other of the fabric, it may be present only in one of the directions, and in particular in the weft direction, for manufacturing reasons.

Indeed, in a particular embodiment, this thread can be inserted inside the same sheath formed during the weaving of the fabric itself, which allows the manufacture of the textile with the integration of the conductive thread during weaving.

Of course, this conductive thread may also be associated with a support fabric by other means to form a pocket provided for this purpose, and in particular by knitting, embroidery or even making techniques.

• réaliser un fil élémentaire en guipant un fil synthétique de guipage sur un fil d'âme métallique ;
• réaliser un fil intermédiaire en guipant ce fil élémentaire sur un fil d'âme élastique ;
• associer plusieurs fils intermédiaire par guipage avec un fil synthétique de liage.

The invention therefore also covers a method of manufacturing an elastic yarn which has properties of conduction of electricity. This method comprises the following steps:

• producing a basic wire by guiping a synthetic wire wrapping on a metal core wire;
• making an intermediate wire by guiding this elementary wire on an elastic core wire;
• combine several intermediate yarns by wrapping with a synthetic binding yarn.

Brief description of the figures

• La figure 1 est une vue en perspective sommaire d'un fil selon un mode de réalisation de l'invention.
• La figure 2 est une vue de détail de la zone II délimitée à la figure 1, dans lequel un seul fil unitaire a été représenté.
• La figure 3 est une vue de détail de la zone III délimitée de la figure 2.

The manner of carrying out the invention, as well as the advantages which result therefrom, will emerge from the description of the embodiment which follows, in support of the appended figures in which:

• The figure 1 is a brief perspective view of a yarn according to one embodiment of the invention.
• The figure 2 is a detailed view of Zone II delimited at figure 1 in which a single unitary wire has been represented.
• The figure 3 is a detailed view of the delimited zone III of the figure 2 .

Of course, the elements shown in the figures have been made in dimensions that have been chosen to facilitate the understanding of the invention, and which can deviate from reality.

Examples of realization

As illustrated in figure 1 , the wire 1 is composed of a bundle of several intermediate wires 2 which are associated and held together by a thin wrapping wire 3.

As illustrated in figure 2 each intermediate wire 2 comprises a core 20 of essentially elastic material, which may be composed of an elastane monotornon for example, typically of a titer of between 20 and 80 decitex. This core 20 is covered by an elementary wire 30, illustrated in detail in FIG. figure 3 .

More specifically, this elementary wire 30 has a core formed of a wire 31, covered by a synthetic thread 32 of title ranging from a few decitex to a few tens of decitex, typically from 10 to 50 dtex. In the form illustrated in figure 3 , the turns formed by the synthetic thread 32 are not contiguous, and reveal the wire 31, to facilitate understanding of the figures. However, as already mentioned, it is possible that these turns are contiguous, so as to reveal only a tiny portion of the surface of the wire 31. This protection can be improved by employing a technique of double wrapping.

Different embodiments can be provided, by varying different parameters. Thus, the example below is given for information only and is not limiting.

Example 1

• Basic thread:
  • copper wire core 25 microns in diameter;
  • polyamide wrapping thread, flat, of 44 dtex;
  • number of turns of the wrapping thread: 1000 turns per meter, (tensioned core) with two threads wrapped in the opposite direction;
• Intermediate wire:
  • 44 dtex monotonon spandex core (without elongation);
  • yarn formed by the elementary yarn with 1000 turns per meter;
• Global thread
  • ten intermediate wires associated without torsion;
  • wrapping with a 13 dtex textured polyamide type synthetic yarn;
  • wrapping with 10 turns per meter.

The maximum elongation of such a yarn is of the order of 250%. The electrical resistance of such a wire is of the order of 3.6 Ω per linear meter. This resistance is almost invariable with elongation.

Example 2

• Basic thread:
  • soul: insulated copper wire 25 microns in diameter;
  • polyamide wrapping thread, flat or textured, formed of 34 filaments, and of 78 dtex;
  • number of turns of the wrapping thread: 600 turns per meter, (stretched core) with two threads wrapped in the opposite direction;
• Intermediate wire:
  • 78 dtex monotorn spandex core (without elongation);
  • wrapping yarn formed by the elementary yarn with 600 turns per meter;
• Global thread
  • five intermediate yarns associated without torsion;
  • wrapping with a textured polyamide synthetic yarn of 22 dtex;
  • wrapping with 10 turns per meter.

The above examples were tested with persistence of electrical conductivity after 20 household washes under standard conditions, and 750 total elongation cycles of the final wire. It follows from the foregoing that the wire designed according to the invention has a high elongation rate, with an almost constant electrical resistance, and good resistance to external aggression, mechanical or chemical.

Claims (12)

1. Method for the manufacturing of an elastic yarn (1) having properties of electrical conduction, comprising the steps which consist in:

   ▪ producing a basic yarn (30) by whipping a synthetic yarn with whipping (32) around a metal core yarn (31);

   ▪ producing an intermediate yarn (2) by whipping the said basic yarn (30) around an elastic core yarn (20);

   ▪ combining several intermediate yarns (2) by whipping with a synthetic binding system yarn (3).
2. Method according to claim 1 characterized in that during the production of the basic yarn (30), the synthetic whipping yarn (32) is wound by adjacent turns around the metal core yarn (31).
3. Method according to claim 1, characterized in that during the production of the intermediate yarn, the elastic core yarn (20) is a monostrand.
4. Elastic textile yarn (1) having electrical conduction properties characterized in that it is formed from an assembly of a multiple number of intermediate parallel yarns (2) assembled together by a synthetic binding yarn (3) wherein each intermediate yarn (2) comprises an elastic core yarn (20) onto which a basic yarn (30) is whipped, in which the basic yarn (30) comprises a metal core yarn (31) whipped with a synthetic whipping yarn (32).
5. Yarn according to claim 4, characterized in that the metal core yarn (31) of the basic yarn is based on a material chosen from the group comprising copper, steel, silver, gold.
6. Yarn according to claim 4, characterized in that the synthetic whipping yarn (32) of the basic yarn is wound by adjacent turns.
7. Yarn according to claim 4, characterized in that the synthetic whipping yarn (32) of the basic yarn is chosen from the group including polyamide, polyester, polypropylene.
8. Yarn according to claim 4, characterized in that the elastic core (20) of the intermediate yarn is a monostrand.
9. Yarn according to claim 4, characterized in that the elastic core (20) of the intermediate yarn (2) is based on a material chosen from the group including elastic polymers, elastane, materials on an elastomer base.
10. Yarn according to claim 4, characterized in that it offers elongation of more than 200%.
11. Yarn according to claim 4, characterized in that it offers resistivity of less than 1 ohm/cm
12. Fabric incorporating into its warp and/or weft a yarn according to claim 4.

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