FR2769785A1 - Textile yarn - Google Patents

Abstract

A textile yarn for making a heated fabric has one or more strands of a conducting material, e.g. stainless steel, insulated by surrounding twisted strands. The yarn is preferably made by a friction spinning procedure and can be woven or knitted into a fabric so that the conducting strands form a series of parallel resistances. The resistances can be connected to copper wires along the edges of the fabric which are in turn connected to a power supply, e.g. of 12 Volts.

Description

The subject of the present invention is:
- an original use of a certain type of textile yarn
- new textile yarns of this type
- heated textile substrates, called first generation, which include in their structure textile yarns of this type and heated textile substrates, called second generation, obtained by thermoforming of first generation textile substrates.

 It is specified, here, for all practical purposes, that the meaning to be given to the expression textile thread, used in the present description and the appended claims, is that, familiar to a person skilled in the art, of thread having interesting characteristics of mechanical resistance (in the direction of its length) combined with a flexibility allowing it to be worked on machine (to be in particular, woven or knitted).

 According to the prior art, heated manufactured articles have been described, such as blankets, clothing, which contain embedded in their insulating structure, electrical resistances connected to electrical power sources. In particular, heated textile supports have been described which contain, entirely wrapped in one or more textile sheets or foams, an electrical resistance in series, with or without own insulation. The said textile or foam layers have the function of better diffusing the heat given off by the resistor and of physically separating the said resistor, rigid, hot (in use) and therefore uncomfortable from the object which one wishes to heat in fine.

Said object may in particular consist of a car seat. Said textile sheets or foams constitute an envelope with said resistance. The manufacturing of this type of heated textile support therefore comprises three stages:
1) that of manufacturing and shaping the resistor (and sometimes its insulator)
2) that of the manufacture of the envelope (which also sometimes performs the function of insulation);
3) that of the establishment and fixing of said resistance in said envelope, by sewing, gluing, heat-setting.

The thickness of the resulting heating product is therefore the sum of the thicknesses of said resistance, of its possible insulator, and of the envelope.

 The main drawback of such a heating product, of relatively heavy manufacture, is its lack of flexibility. We can also blame it for a non-uniform distribution of heat.

In the context of the present invention, the Applicant proposes a new concept for this type of product: textile support heated by effect
Joule. It developed this new concept by seeking to reduce the manufacturing costs of said product, to better distribute the heat emission in the volume or on the surface of said product, to reduce the thickness of said product while giving it maximum flexibility, very close to that of an equivalent textile support without electrical resistance within it.

 Said concept is based on an original use of a certain type of textile yarn: composite textile yarn whose composite structure includes at least one conductive filament electrically insulated by means of fibers and / or yarn (s).

 Threads of this type have already been described, according to the prior art, but in a completely different context; recommended for other uses. Thus, there are anti-cut protective gloves produced by weaving reinforced plied yarns, yarns having in their core a metallic filament intended to reinforce their mechanical properties. Wires of this type have also been used, according to the prior art, to produce protective means with respect to electromagnetic waves.

 According to its first object, the present invention therefore relates to an original use, as a heating wire, of a wire of the type mentioned above; composite textile yarn, the structure of which includes at least one conductive filament electrically insulated by fibers and / or yarn (s). To electrically insulate said conductive filament, fibers and / or at least one wire are added thereto.

I1 intervenes, in the structure of said wire, at least one conductive element and in the context of the use recommended according to the invention, the said conductive element (s) is energized so that '' it (s) releases (s) by Joule effect of calories. For an optimization of this release of calories by the textile yarn, there are several parameters: - nature of the material constituting the said conductive filament (s);
- length, section of said filament (s),
- number of filament (s) involved,
- nature of the fibers and / or yarn (s) involved in isolating the said (s) filament (s),
- thickness of the insulating coating based on said fibers and / or wire (s).

 In the context of the present invention, use is made of the conductive filament (s) (at least one of said conductive filament (s) if more than one is involved) for its (their) ability to transport an electric current (and therefore to release heat by the Joule effect) and not for its (their) mechanical properties (it is in particular not intended to constitute a rigid reinforcement ... on the contrary, it is generally aimed at imparting maximum flexibility to the product in the structure of which it intervenes) or for any other property.

 We have spoken above of the use, as a heating wire, of a textile wire of the type mentioned above. It will be understood from consideration of the words below that it generally intervenes, jointly, several wires of said type, to obtain the expected effect: the production of a substrate capable of releasing heat due to the fact that it incorporates in its structure at least one such wire.

 Such a substrate can exist in multiple variants.

In fact, in a non-limiting manner, in the context of the present invention, three main types of use are used, as heating wire, of textile threads whose characteristics given above are specified further in the present description.
e Such a wire can be used as such. One can in particular design a plate warmer resulting from the winding of such a wire, in the form of a coil.

 At least one such wire, acting as a wire or within a more complex structure, can constitute at least in part a part attached to a support; All of said insert and of said support constituting a heating substrate. One can in particular design patterns based on such wires, secured to a support; said patterns constituting both decorative elements and heating elements. It is also conceivable, a coil of the above type stabilized in a textile envelope. It is also conceivable to incorporate such threads into a textile substrate, of more or less loose structure. In the context of the present variant, said wires constitute parts added to said substrate, they intervene downstream from the manufacture of said substrate, they do not form an integral part thereof. ns advantageously replace the electrical resistances of the prior art ...

 At least one such thread can be used to make a heating textile substrate; said textile yarn forming an integral part of the interlacing of yarns constituting said heating textile substrate (said yarn being intrinsically part of said textile substrate, said yarn having intervened at the stage of manufacture of said substrate in place of a yarn not containing conductive filament). In the context of the present variant, a particularly preferred variant, said thread (said threads) is used to develop an intrinsically heating textile substrate. Such a substrate can, surprisingly, combine performance in terms of heating and flexibility ... Said substrate can result from an intertwining of wires, consisting of 100% of heating wires within the meaning of the invention (it is recalled here that the conductive filaments of said wires are insulated by fibers and / or wire (s)) or from an interlacing of wires, only a part of which consists of heating wires within the meaning of the invention. Only heating wires or heating wires are used, generally on a machine, in combination with other more conventional wires.

In any event, we can already indicate here that any intervening heating wire is not inevitably connected to the electrical power source.

The textile substrate produced at least in part with at least one heating textile yarn can in particular be of the woven, knitting or mixed woven / knitting structure type.
n can in particular be knitted, woven on a shuttle loom, prepared according to a mixed knitting / weaving technique, with a single heating wire, constituting a resistance in series.

 I1 is however advantageously developed with several (n) heating textile yarns; said n heating textile yarns being advantageously used simultaneously (during its development) so as to constitute electrical resistances in parallel. This result can in particular be obtained by weaving on a loom which is not a shuttle loom, by knitting according to the techniques of picked or knitted mesh, by implementing a mixed knitting / weaving technique with a warp knitting. Thanks to the intervention of such resistors in parallel, the result obtained can be optimized both in terms of homogeneity of the heating and in terms of product flexibility. It is thus possible to obtain a precise power per unit area of the substrate while retaining said substrate an attractive flexibility.

 In the context of this variant of the invention, it is particularly recommended to use n heating textile yarns during the manufacture of a woven fabric; said n heating textile yarns intervening, advantageously regularly, in particular in place of a non-heating weft yarn; warp yarns also consisting of non-heating yarns.

 In the context of the present preferred variant of the invention, at least one heating wire is therefore used in the preparation of an intrinsically heating textile substrate.

A person skilled in the art will already have understood, on reading the above, all the outlets which are open to such textile substrates. we can notably intervene
- in the development of heated automobile seats: within the structure of such seats, or even at the level of the covering thereof, insofar as they can completely have all the characteristics of a conventional textile fabric ;
- in the development of clothing, heating blankets (even survival)
- in the development of furnishing materials, such as wall coverings or carpets;
- in the development of envelopes, protective linings from the cold, intended for example to protect diesel oil tanks, fuel tanks ...

The above list is by no means exhaustive. It illustrates in a nonlimiting manner outlets for the textile substrates of the invention called first generation. It will be seen below, in the present text, that said first generation textile substrates can also serve as precursors to second generation textile substrates. We realize that the field of application of the invention - original use of certain composite textile yarns - is vast
We now propose to describe in more detail said composite textile yarns. We have recalled further the definition of a textile thread. It has also been specified that said heating textile yarns, within the meaning of the invention, have a composite structure which includes at least one conductive filament electrically insulated by fibers and / or yarn (s) (textiles).

 Said conductive filament ensures the expected result: Joule heating. To this end, it must be able to be connected to an electrical power source. It is generally connected to it by its stripped ends, free of fibers and / or wire (s) (which ensure, over its entire length, its electrical insulation). Said filament can be of any electrically conductive material. It is advantageously made of copper or stainless steel.

We speak of a filament insofar as it has a small diameter for a substantial length. Its diameter is in fact generally between 0.01 mm and 1 mm. It will be recalled, with reference to said diameter, that said filament enters the structure of a textile thread intended in particular for generating flexible textile substrates and that it does not intervene to ensure the function of internal reinforcement of said thread
Said filament advantageously constitutes at least in part the core of said wire.

 It has been indicated that the composite structure of the textile heating yarns includes at least one such conductive filament. Indeed, it can contain several conductive filaments, arranged in various ways. The said conductive filament (s) is (are) electrically insulated by a coating of fibers and / or wire ( s) textiles; this coating can be declined according to many variants.

The textile heating yarns of the invention differ mainly from the electrical resistances of the prior art by the nature of said insulating coating.

 The textile fibers and / or yarn (s) intended to electrically insulate the said conductive filament (s) are obviously fibers and / or yarn (s) made of an insulating material; in particular fibers and / or yarns of polyester, polyamide, cellulose, viscose, polypropylene, or even glass. Advantageously, such fibers and / or yarns can be found in a mixture. The intervention of glass fibers and / or wire (s) is not a priori particularly recommended insofar as the electrical insulation produced from such fibers and / or wire (s) also constitutes thermal insulation against vis-à-vis the calories released by the conductive filament (s) ... On the other hand, in certain contexts, in particular if one aims at developing second generation heating substrates by thermoforming, one recommends the intervention, alone or as a mixture, of fibers and / or thermoformable yarn (s) ... It is incidentally noted here that said yarns can intervene as well at the level of the core of the yarn, as at the level of the coating of said core, at these two levels ... while said fibers only intervene at said insulating coating. It is also specified that said yarns capable of operating at the level of the insulating coating are both yarns, in the conventional sense of the term, composed of fibers, as well as continuous filaments obtained by extrusion.

 Textile yarns, the use of which as heating yarns is recommended according to the invention can thus be used in numerous variants.

Generally said textile threads have a diameter of between 0.5 and 5 mm.

 Their fiber and / or textile component (s) may have a more or less complex structure. We talked about fibers and / or yarn (s); it should indeed be understood that the intervention of a single wire is not excluded. Thus, a textile heating wire of the invention can consist of a core - at least one electrically conductive filament - around which is wrapped, tightly, a single insulating wire.

 In a particularly advantageous manner, it is recommended in the context of the invention, the use as heating wire, of the types of composite yarns below - composite textile yarn comprising a core with several filaments, at least one of said filaments is a conductive filament and in which optionally all of said filaments are held in torsion; core with several filaments around which is wrapped at least one insulating wire; - composite textile yarn comprising at least one conductive filament, which constitutes at least in part the core of said textile yarn, coated with insulating fibers, the cohesion of said coating of fibers having been obtained by twisting; said composite textile yarn having advantageously been obtained by the friction spinning process.

 The textile yarns of the first type above exist in particular according to two main variants: with a multi-filament core, plied, or not. Such textile threads, with a plied core, have already been used, as indicated in the introductory part of this description, to develop anti-cut gloves. Their plied core may in particular comprise a metallic filament and two polyamide filaments; around said core, there is advantageously wrapped a textile thread, made of natural fibers. In the context of the present invention, said metallic filament is used not for its mechanical properties but for its conductive nature.

 The use of textile yarns of the second type above is particularly preferred. The core of said threads is at least partly made up of at least one conductive filament. The said conductive filament (s) associated or not with at least one other textile filament is (are) isolated by a coating of fibers. The cohesion of said coating of fibers is obtained by twisting them around said core. Several techniques can be used to generate said coating of fibers around said core. One can in particular implement a ring spinning (ring process) or, in a particularly advantageous manner, a friction spinning (friction spinning). These spinning techniques are familiar to those skilled in the art. The second mentioned, preferred (that of friction spinning), known since the years 1960-1970, consists mainly of passing the core wire (s) between two rollers, arranged almost tangentially, set in rotation in the same way; the space between said two rollers being supplied, from a wick breaker, by fibers.

 This technique is currently used to, for example: - develop large diameter yarns, used as weft yarns in the manufacture of textile supports of the mop type. Said absorbent yarns are generally based on cellulosic fibers. They are reinforced or not by a filament which constitutes its soul (polyester filament, for example). It is indeed also possible to implement said spinning process by friction without using a core filament ...

- develop flame retardant composite yarns, intended for example for the manufacture of aircraft carpet. Said composite yarns comprise a polyester core yarn, coated with glass fibers
According to the invention, it is therefore very particularly recommended to use as heating threads the composite textile threads of the above type - textile thread comprising at least one conductive filament, which constitutes at least partly the core of said coated wire insulating fibers; the cohesion of said coating of fibers having been obtained by twisting -; said composite textile yarns having advantageously been obtained by the technique of friction spinning.

 Such threads, insofar as their core contains at least one conductive filament are new and constitute another object of the present invention.

Said core is in fact made up of said conductive filament, or even of several such conductive filaments or comprises at least one such conductive filament associated with other filaments.

 Particularly preferred, in themselves and for their use as heating wires, wires of this type whose core contains at least one copper or stainless steel filament and whose coating is based on fibers of polyester, polyamide, cellulose, viscose, polypropylene ... the said fibers advantageously involved in mixing. The intervention of hot-melt fibers is recommended, in particular when the aim is to prepare, with the composite yarns of which said fibers constitute the coating, thermoformed textile substrates. This is clarified later in this text.

 The use, as heating wires, of the two types of composite wires described in detail above (it is recalled here that the second, original, is currently claimed as such) is therefore preferred, but the first object of the present invention is not limited to the use of these two types of son. Any textile yarn whose composite structure includes at least one conductive filament electrically insulated by fibers and / or yarn (s) is suitable. One can in particular use, within the framework of the invention, larger wires, resulting from the assembly of at least two wires of the above types ...

It has been seen that said wires can, in the context of the present invention, be used as such;
+ within a more complex structure; said wires constituting at least in part a part attached to a support; all of said insert and of said support constituting a heating substrate (advantageously, a heating textile substrate);
or + as a constituent element of an intrinsically heating textile substrate.

 Such heated textile substrates constitute the third object of the present invention.

 Said heated textile substrates are of the type of heated textile substrates of the prior art insofar as they include in their structure at least one electrical resistance capable of being energized to release, by Joule effect, calories. However, typically, said resistance therefore does not consist of an electrical resistance of the prior art but of a textile yarn whose composite structure includes at least one conductive filament electrically insulated by fibers and / or yarn (s). Said textile substrates of the invention include in their structure heating wires as described above. Said textile substrates can in particular be of two types; the heated textile thread (s) acting either as an added piece, or in the structure of an added piece, on a textile support or as an intrinsic constituent of said textile substrate. These two types of textile substrates have already been described with reference to the use of the heating wires of the invention. The second of said types is particularly preferred.

Thus the subject of the present invention is also: - textile substrates of the type consisting essentially of a textile support and at least one piece attached to said textile support; at least one heating textile thread of the aforementioned type constituting at least in part such an insert;
- textile substrates obtained by interlacing yarns, and in particular of the woven, knitting or mixed woven / knitting structure type; at least one heating textile thread of the aforementioned type constituting one of said interlaced threads; textile substrates of this type being particularly preferred.

 With reference to the first type of heated textile substrate, it is recalled that it may owe its heating character to an insert which therefore contains at least one heating wire or to at least one such wire which itself constitutes an insert. In the latter case, one or more heating wires have been incorporated into the finished textile support.

 With reference to the second type of heated textile substrate, it is recalled that it can include or consist of a single heated textile yarn or that advantageously, n heated textile yarns intervene in its structure.

In the context of this variant, said intervening heating wires advantageously constitute a network of electrical resistors in parallel.

 The heated textile substrates of the invention are advantageously woven, knitted, woven / knitted fabrics containing 100% of heated textile threads or woven, knitted, woven / knitted fabrics in the structure of which heated textile threads are found in place of non-heating textile yarn; said textile heating wires intervening in greater or lesser numbers, to advantageously form resistors in parallel.

The textile heating yarns which are involved in the structure of the textile heating substrates of the invention are advantageously of the types described in detail above:
- Wire comprising a core with several filaments, at least one of the filaments of which is a conductive filament and of which optionally all of said filaments are held in torsion; core with several filaments around which at least one insulating wire is wrapped
- original thread comprising at least one conductive filament which constitutes at least part of its core; said conductive filament being coated with insulating fibers whose cohesion has been obtained by twisting (wire advantageously obtained by the spinning process by friction).

 Said heating wires, whatever their exact structure and their density of intervention in the textile substrate, must be able, in order to exercise their function of heating element, to be energized. In general, they have ends at the level of which the conductive filament (s) which they contain is (are) stripped (ends free of the coating based on fibers and / or wire (s) ). At these ends, said filament can be connected to an electrical power source. The connection can be of any known type. When several heating wires intervene in parallel, the ends of each of said wires are advantageously connected to the same conductive element which is itself connected to the electric power source. In any event, a person skilled in the art is able to arrange the supply circuit for the heating wires of the heating textile substrates of the invention. We do not rule out the intervention of several circuits of this type within the structure of the same heating substrate.

 According to its last object, the invention finally relates to textile substrates of a particular type, so-called second generation textile substrates, obtained by thermoforming of preferred textile substrates as described above (so-called first generation textile substrates), in the structure of which there is intrinsically involved at least one thermoformable heating textile yarn. Said textile heating wire is thermoformable by the presence in its structure of fibers and / or insulating wire (s), hot-melt, for example polypropylene. By heat treatment of an interlacing of threads which in fact contain textile heating threads with heat-fusible insulating fibers and / or thread (s) - said heat treatment ensuring at least partial melting of said heat-fusible fibers and / or thread (s) - in the context of the present invention, an thermoformed heating textile substrate is obtained in an original manner.

 The invention is illustrated by the example below.

In the context of said example, we first prepared:
- an original composite textile yarn (heating wire of the invention) using a friction spinning process;
- another composite textile yarn, using a friction spinning process; these two types of yarn being intended to constitute weft yarns of a heating textile substrate of the invention obtained by weaving.

.obtaining and characteristics of. threads used
A friction spinning process is implemented in a conventional manner by scrolling - at a speed of 180 m / min -, between the intervening rollers, a stainless steel filament (z 0.12 mm) and feeding the space between said rollers by a mixture of polyester fibers and viscose fibers (mixture 50-50% by weight). Said polyester fibers are DACRON29 fibers, sold by the company Du Pont de Nemours (38 mm cut, 1.6 dtex titer); said viscose fibers are of the LENZING type, sold by the company Lenzing (38 mm cut, 1.3 dtex titer).

 A composite textile yarn (A) is thus obtained, the core of which, consisting of said conductive filament, is surrounded by insulating fibers. Said wire (A) has a diameter of approximately 1 mm. It is original due to the nature of the filament constituting its soul.

 The same friction spinning process is implemented, using a polyester filament (having a linear mass of 1 g per 30 m) to form the core of the prepared yarns (B). Said polyester filament is similarly surrounded by a coating of polyester fibers and viscose fibers. A composite textile yarn (B) is thus obtained, with a diameter of approximately 1 mm, which does not contain a conductive filament.

 Said threads (A) and (B) - large threads - are intended to constitute weft threads.

 The warp threads (C) to be associated with said weft threads are polyester filaments of the type of those constituting the core of the threads (B) (linear density of 1 g per 30 m).

 <made accessible to a conductive element, a copper wire provided on each longitudinal edge (parallel to the warp) of the fabric obtained. Said copper wires are themselves connected to a suitable electrical supply.

 The fabric prepared in the context of the present example is entirely suitable for being included in the structure of a seat of motor vehicles. Supplied with 12 V (by an adequate connection to the battery of said vehicle), it is capable of rapidly releasing the calories required.

Claims (14)

- Claims  1. Use of at least one textile yarn, the composite structure of which includes at least one conductive filament electrically insulated by fibers and / or yarn (s), as a heating yarn.  2. Use according to claim 1, of at least one textile thread of the aforementioned type to constitute at least in part a piece attached to a support; The whole of said part and of the support constituting a heating substrate.  3. Use according to claim 1, of at least one textile thread of the aforementioned type, for producing a heated textile substrate; said textile thread forming an integral part of the interlacing of threads constituting said heating textile substrate, in particular of the woven, knitted or mixed woven / knitted structure type.  4. Use according to claim 3, n textile threads of the aforementioned type; said n textile yarns being advantageously used simultaneously in the production of the textile substrate heating by interlacing of yarns so as to constitute within it electrical resistances in parallel.  5. Use according to any one of claims 1 to 4, at least one textile thread of the aforementioned type; said composite textile yarn comprising a core with several filaments, at least one of said filaments of which is a conductive filament and of which optionally all of said filaments are held in torsion; core with several filaments around which is wrapped at least one insulating wire.  6. Use according to any one of claims 1 to 4, of at least one textile thread of the aforementioned type; said composite textile yarn comprising at least one conductive filament, which constitutes at least partially the core of said textile yarn, coated with insulating fibers, the cohesion of said coating of fibers having been obtained by twisting; said composite textile yarn having advantageously been obtained by the friction spinning process.  7. Textile yarn, the composite structure of which includes at least one electrically insulated conductive filament, characterized in that said conductive filament, which constitutes at least partially the core of said textile yarn, is coated with insulating fibers, the cohesion of said coating with fibers having been obtained by twisting; said textile yarn having advantageously been obtained by the friction spinning process.  8. Heating textile substrate including in its structure at least one electrical resistance capable of being energized to release, by effect Joule, calories, characterized in that said electrical resistance is a textile wire whose composite structure includes at least one conductive filament electrically insulated by fibers and / or wire (s).  9. The textile substrate according to claim 8, of the type consisting essentially of a textile support and at least one piece attached to said textile support, characterized in that said textile thread of the aforementioned type constitutes at least in part such an attached piece.  10. The textile substrate as claimed in claim 8, obtained by interlacing of yarns, and in particular of the woven, knitting or mixed woven / knitting type, characterized in that said textile yarn of the above-mentioned type constitutes at least one of said interlaced yarns.  11. Textile substrate according to claim 10, characterized in that n textile threads of the aforementioned type intervene in its structure, to advantageously constitute a network of electrical resistors in parallel.  12. Textile substrate according to any one of claims 8 to 11, characterized in that said electrical resistance is a composite textile yarn as defined in claim 5 or claim 6.  13. Textile substrate according to any one of claims 8 to 12, characterized in that said textile thread of the aforementioned type has ends at which the conductive filament (s) is (are) stripped for its (their) connection to the power source.  14. Thermoformed heating textile substrate, including in its structure at least one electrical resistance capable of being energized to release, by Joule effect, calories, characterized in that it is obtained by thermoforming a textile substrate according to the any one of claims 10 to 13 - said textile substrate including at least one textile thread of the aforementioned type with heat-insulating fibers and / or thread (s) -; said thermoforming having been implemented under conditions ensuring at least partial melting of said thermofusible insulating fibers and / or wires.