BRPI0807510B1 - ELECTRICALLY CONDUCTIVE ELASTIC COMPOUND YARN, PARTICULARLY FOR RFID TEXTILE LABELS, USE THEREOF, AND PRODUCTION OF A BRAIDED TISSUE, KNITTED TISSUE OR STITCHED THERE. - Google Patents

Abstract

In order to provide an electrically conductive, elastic, textile-processable compound thread (2), and protect the same from breaking under stress, the invention provides that the compound thread (2) has at least one conductor thread (4), a textile tension relief thread (6), and a textile binder thread (8). The compound thread (2) is produced on a knitting or double rib machine using textile binder threads (8), or knitted threads, or on a weaving machine using weft threads and textile binder threads (8). The tension relief thread (6) is disposed at higher tension than the conductor thread (4) and can be stressed using higher tension.

Description

(54) Title: ELECTRICALLY CONDUCTIVE ELASTIC COMPOUND YARN, PARTICULARLY FOR RFID TEXTILE LABELS, USE OF THE SAME, AND PRODUCTION OF A BRAIDED FABRIC,

KNITTED OR KNOTTED FABRIC THEREFORE.

(51) lnt.CI .: D02G 3/32; D02G 3/44 (30) Unionist Priority: 12/02/2007 CH 231/07 (73) Holder (s): TEXTILMA AG (72) Inventor (s): FRANCISCO SPEICH

Descriptive Report of the Invention Patent for ELECTRICALLY CONDUCTIVE ELASTIC COMPOUND YARN, PARTICULARLY FOR RFID TEXTILE LABELS, USE OF THE SAME, AND PRODUCTION OF A BRAIDED, KNITTED OR THREADED FABRIC.

Technical Field

The present invention relates to an electrically conductive elastic composite yarn, particularly an antenna yarn for RFID textile tags. A composite yarn is to be understood in this context as meaning a yarn that is composed of different elements of yarn or fibers. In addition, the invention relates to the use of the same and to the production of a woven fabric, knitted fabric or woven with it.

Prior Art

It is known, for example, from WO 2002/071605, to incorporate in a textile material a conductive thread that serves as an antenna for a transponder on a label. A conductive thread like this consists, for example, of copper and is incorporated by the weave during the production of the textile material or is subsequently applied to a textile material by means of a border technique. Therefore, if the conductor wire itself is designed to be elastic, the known conductor threads are not suitable, since, in particular, the elasticity of the metal wire is not sufficient to maintain the elasticity of the total wire.

WO 2004/027 132 A1, and also the first application DE 102 42 785 A1 for this one, providing grounds for priority, describe an electrically conductive wire with an elastic core wire and at least one electrically conductive wire wrapped around the wire core, and at least one electrically non-conductive wrap around the core wire. In this case, the stretching capacity of the electrically conductive total wire is to be limited by the surrounding wire. In this case, it is essential for the yarn of WO 2004/027 132 A1 that the elastic core yarn provides yarn elasticity, while the wrapping yarn ensures that the conductive yarn cannot break, as the wrapping yarn limits the ability to stretch. the wire. However, a yarn like this can only be used to a limited extent in textile applications and does not appear to be suitable when a yarn that is not expected to have elastomeric properties is to be used. WO 2006/128633 and also US 2004/237 494 A1 also describe an elastic conductive wire with an elastic core and with a conductive wire wrapped around the elastic core, with the same preconditions for proper application as in WO 2004/027 132 A1.

Unrelated US 47 50 324 A1 (composite yarn for use in the high temperature range) describes a composite yarn and a composite yarn for processing fragile yarns made of ceramics or the like for knitting and sewing machines, in which a load-absorbing flexible core yarn and the fragile yarn, together with a flexible mooring yarn, are arranged in such a way that the composite yarn, in a curved state with a small radius, has a greater tensile strength than the yarn fragile.

All the yarns mentioned above have a disadvantage in that they cannot be incorporated, free of flaws, in a textile material, and the electrical function is also not yet guaranteed safely after incorporation in a textile material.

Presentation of the Invention

The purpose of the invention is to provide an electrically conductive elastic composite yarn that can be incorporated, as flawless as possible, into a textile material and whose function is still ensured even after incorporation into a textile material.

The objective is achieved, according to the invention, by means of a processable composite yarn suitable for weaving and electrically conductive according to claim 1. The strain relief yarn is arranged under higher tension, when compared to the conductive yarn, so that, in the case of tension in the composite wire, on the one hand, the strain relief wire is first subjected to tension. In addition, the strain relief wire has a greater load-bearing capacity than the conductive wire. The strain relief wire is to have an elasticity of 3% to 40%, preferably 5% to 12%. The composite yarn is knitted or braided together with textile mooring threads. As a consequence, the result of the measurements of the invention is, first, that the metal wire or other conductive wire is protected against mechanical overvoltage and excessive stretching by the strain relief wire, the electrically conductive composite wire obtaining mechanical resistance because of the textile mooring thread. The strain relief wire in this case is to consist of textile materials.

Advantageous shapes of the electrically conductive elastic composite yarn are described in claims 2 to 15.

It is advantageous, according to claim 2, if the conductive wire is arranged in such a way that it can be stretched at least to its limit of proportionality, before the conductive wire can break under any condition. For those strain relief wires for which no proportionality limit can be specified, for example, for strain relief wires consisting of specific plastics, it is advantageous if the strain relief wire is arranged to be so much smaller that the resistance load on the lead wire will begin only when the strain relief wire tension has reached a magnitude that corresponds to the break resistance of the lead wire (claim 3).

In order to further protect the conductor wire as defined in claim 4, advantageously the strain relief wire can be arranged in relation to the conductor wire in such a way that the strain relief wire can be stretched to its limit of break before the conductor wire can break. Advantageously, at the breaking limit of the strain relief wire, the conducting wire in this case also does not reach its breaking limit, but only begins to be subjected to the load, or at most reaches its proportionality limit.

It is advantageous if, according to claim 5, the mooring threads tie between 15 and 30 times per cm, preferably between 20 and 24 times per cm.

As stated in claim 6, the textile binding yarns preferably consist of natural or synthetic fibers.

The strain relief yarn is to be understood here as an individual yarn, possibly consisting of a plurality of fibers, or else a compound consisting of several individual yarns. For advantageous production, the strain relief wire may consist of thermally contractile material. The strain-relief yarn may consist of natural fibers or synthetic fibers, preferably polyamide, polyester or aramid (claim 8). The conductive yarn can advantageously also have a metallic elasticity (claim 9) and consist of metal or metal alloys, but also of metallic coated metal fibers, preferably of polyamide (claim 10). However, it can also be advantageous if the lead wire is a compound that has at least one metallic and at least one metal-coated synthetic wire (claim 11). This is particularly advantageous when electrical bridging occurs at least in parts between the metallic and the metallic coated metal wire (claim 12). However, even a plurality of conductive wires or conductive fibrils can be provided, which then maintains a continuous conductor function by forming an electrical bridge in the event of the rupture of one of the conductive wires (claim 13).

It is advantageous to use an elastic and electrically conductive composite textile yarn previously described as an antenna for RFID textile tags or, more generally, as a current conductor in braided, knitted and entangled fabrics (claim 14).

By means of an elastic and electrically conductive textile composite yarn like this, according to claim 15, a braided fabric, knitted or braided fabric is advantageously produced in a separate process and is finally incorporated into a braided fabric, knitted or braided fabric .

The elements to be used according to the invention, mentioned above and also claimed and described in the following exemplary modalities, are not subject to any exceptional special conditions in terms of their size, shape, use of the material and technical design and, therefore, the Selection criteria known in the respective field of use can be applied without restriction.

Brief Description of Drawings

Exemplary modalities of the invention are described in more detail below with reference to the drawings, in which:

Figure 1 shows an electrically conductive knitted elastic composite yarn according to a first exemplary embodiment of the present invention;

Figure 2 shows an electrically conductive braided elastic composite wire according to a second exemplary embodiment of the present invention;

Figure 3 shows a composite wire with a break resistance graph.

Ways to Implement the Invention

Figure 1 shows a composite wire 2 according to a first exemplary embodiment of the present invention, in which a freely extending conductive wire 4 and a strain relief wire 6 arranged in order to be more stretched when compared to the latter, they are knitted together with a mooring thread 8. In other words, this means that the strain relief thread 6 is arranged under greater tension than the conductor thread

4. Lead wire 4 and strain relief 6 are extended here in such a way that lead wire 4 is only subjected to tensile stress at point a + b only when strain relief wire 6 reaches its limit rupture 62 at a stretch of approximately 28%. In addition, the tensile strength of the strain relief wire 6 is greater than that of the conductive wire 4. This, therefore, corresponds to case II of the break resistance graph in figure 3.

This composite yarn 2 is produced in a knitting machine or Raschel. In this exemplary modality, the composite yarn has approximately 22 knitting stitches per cm. the strain relief thread 6 is made of synthetic fibers, consisting here of polyamide, and has a tensile strength 62 of approximately 28% in relation to its stretching. Conductive wire 4 is made of metal, in this case a silver / copper alloy, but it can also alternatively consist of metal-coated fibers, here made of polyamide. According to a further alternative of this first exemplary embodiment, a conductive thread 4 is produced from a metallic thread and a metallic coated thread composed of polyamide fibers. In this case, because of the geometric arrangement, the formation of an electric bridge then takes place, at least in places, between the metal wire and the metal-coated wire composed of polyamide fibers. Higher conductivity of the metal wire can thus be associated with a resistance to breakage, thus combining the advantages of a metal wire and a metal-coated wire.

In a second exemplary embodiment according to figure 3, the composite yarn 22 is produced on a weaving machine. In this case, the conductor yarn 4 is interwoven like a weft yarn with the mooring yarn 8 and the strain relief 6 which is kept taut. Here, too, all the other features and alternatives of the knitted composite yarn 2 described above also apply to the twisted composite yarn 22.

Figure 3 shows, in case II, an example of a break resistance graph of a composite wire 2 with the two conductor wires 4. It can be seen here that the break resistance 62 and the elasticity 60 of the strain relief wire 6 , which in this case consists of Trevira 55 dtex, are substantially greater than the tensile strength 42 and the elasticity 40 of the conductive wire 4 which consists of an AgCU metal wire. The strain relief wire 6 reaches its proportionality limit 60 at a stretch of approximately 5% and its breaking limit 62 at a stretch of approximately 28% under a breaking force of up to 10 newtons.

With a looser uniform configuration of the loose arrangement of the conductive wire 4, the composite wire can be stretched even further up to 40%, the strain relief wire 6 in this case already being broken, until the conductive wire 4 begins to be stretched only a + b + ce, with an additional stretch of 1%, reaches its limit of proportionality 40 and then, through a stretch and a breaking force of 0.48 newton, it also breaks. This corresponds to case III in figure 3.

The advantages of the invention itself, however, are also achieved even in case I according to figure 3, or even below it, in the case _; conductor wire 4 is arranged to be only so much looser than strain relief wire 6 in which conductor wire 4 begins to be loaded at the proportionality limit 62 of strain relief wire 6, so that, under additional load, the conductive wire 4 is subjected to tension up to its proportionality limit 42 and then up to its breaking limit 40.

List of Reference Symbols 2 Knitted composite yarn 4 Concluding Fió 6 Strain relief wire 5 8 Mooring wire 22 Braided composite wire 40 Proportionality limit or flow point of the conductive wire 42 Conductive wire break limit 10 60 Strain relief wire proportionality limit 62 I Strain relief wire break limit Lead wire configuration beyond the limit of proportionality of the strain relief wire li Lead wire configuration beyond the limit of 15 III strain relief wire break Lead wire configuration 40% further from the lead wire strain relief, well behind the break wire break limit tension relief The Start of stretching of the conductive wire in case I 20 a + b Beginning of stretching of the conductive wire in case II a + b + c Beginning of stretching of the conductive wire in case III

Claims (14)

1. Processable composite yarn suitable for weaving, elastic, electrically conductive (2, 12, 22, 32) that has at least one conductor yarn (4), one tension-relieving textile yarn (6) and one textile lashing yarn ( 8), the strain relief wire (6) being arranged under higher stress and having a greater load-bearing capacity than the conductive wire (4), and the strain relief wire (6) having an elasticity (60 ) from 3% to 40%, preferably from 5% to 12%, and the composite yarn (2) being produced in a knitting or Raschel machine with textile binding yarns (8) or stitching yarns or in a machine weaving with weft yarns and textile mooring yarns (8), characterized by the fact that at least two conductive threads or conductive fibrils are incorporated in such a way that the formation of an electric bridge occurs in the event of the rupture of one of the conducting threads. 2. Composite wire according to claim 1, characterized by the fact that one of the conductive wires (4) is arranged in such a way that, when the proportionality limit (60) of the strain relief wire (6) is reached , the tensile load on this conductive wire (4) is less than its breaking limit (40). Composite wire according to claim 1, characterized by the fact that one of the conducting wires (4) is arranged in such a way that its resistance load begins when the tension of the strain relief wire (6) reaches a magnitude which corresponds to the breaking strength (42) of this conducting wire. Composite wire according to claim 1 or 2, characterized in that one of the conducting wires (4) is arranged in such a way that, when the breaking limit (62) of the strain relief wire (6) is achieved, the tensile load on this conductive wire (4) is less than its breaking limit (42), preferably also less than its proportionality limit or flow point (42). Composite yarn according to any one of claims 1 to 4, characterized in that the textile mooring yarns (8) tie up to 30 times per cm, preferably 20 to 24 times per cm. 6. Composite yarn according to claim 5, characterized by the fact that the textile mooring yarns (8) consist of natural or synthetic fibers. Composite wire according to any one of claims 1 to 6, characterized in that the strain relief wire (6) consists of thermally contractile material. Composite yarn according to any one of claims 1 to 6, characterized in that the strain-relief yarn (6) consists of natural fibers or synthetic fibers, preferably of polyamide or polyester or aramid. 9. Composite wire according to any one of the preceding claims, characterized by the fact that one of the conducting wires (4) has a metallic elasticity (40) of up to 2%. Compound yarn according to claim 9, characterized in that this conductive yarn (4) consists of metal or metal alloys or metal-coated synthetic fibers, preferably polyamide. Composite yarn according to any one of claims 1 to 9, characterized in that the conductive yarns (4) have at least one metallic and at least one metal-coated synthetic yarn. 12. Composite wire according to claim 11, characterized by the fact that the formation of an electric bridge occurs at least in parts between the metallic and the metallic coated metal wire. 13. Use of an electrically conductive elastic composite yarn as defined in any one of claims 1 to 12, characterized in that it is used as a current conductor in braided fabrics, knitted and interwoven fabrics, in particular as an antenna for RFID textile tags . 14. Method for the production of a braided fabric, knitted or braided fabric, characterized in that a composite yarn as defined in any one of claims 1 to 12 is produced in a separate process and is finally incorporated into a braided fabric, knitted or entangled fabric. 1/3 2/3 WD 3/3