Bi-elastic fabric with parallel warp yarns, and associated process
A fabric with parallel warp yarns and elastane core weft yarns, combined with a post-treatment process, addresses the limitations of Pas de Gauce looms by providing elasticity in both warp and weft directions, enhancing production efficiency and properties.
Patent Information
- Application Number
- FR2023008592
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-08-09
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2043-08-09
AI Technical Summary
Existing looms with Pas de Gauce systems have low manufacturing speed and limited diversity in tissue structures, and fabrics produced using these systems lack elasticity in both warp and weft directions without additional post-treatment.
A fabric design with parallel warp yarns, where at least one warp yarn elongates less than 30% and recovers its original shape, combined with weft yarns having an elastane core covered by a filament or fiber layer, and a post-treatment process involving steaming and solvent impregnation at 75°C or higher to enhance elasticity.
The fabric achieves elasticity in both warp and weft directions, simplifying the weaving process and enabling easy production on conventional looms, with enhanced elastic properties post-treatment.
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Abstract
Description
Title of the invention: Bi-elastic fabric with parallel warp yarns, and associated method
[0001] The present invention relates to a fabric, advantageously of compression, comprising warp yarns and weft yarns, and the associated manufacturing process.
[0002] Such a fabric is, for example, for medical use.
[0003] More particularly, it relates to a fabric capable of exhibiting elasticity characteristics in the direction of the warp and in the direction of the weft.
[0004] Such a fabric is likely to be used in medical compression devices such as bandages, compression garments, orthotics or lumbar belts.
[0005] Such fabrics are generally made with looms equipped with systems known as English Tower or Pas de Gauce.
[0006] This system is capable of allowing two elastic warp yarns to cross between two weft yarn insertions. This particular structure gives the fabric its elasticity in both the warp and weft.
[0007] However, such a loom has a relatively low manufacturing speed.
[0008] Furthermore, the diversity of tissue structures that can be achieved in this way is limited.
[0009] The aim of the invention is then to propose a fabric capable of exhibiting elasticity characteristics in the direction of the warp and in the direction of the weft without using the Pas de Gaue system.
[0010] For this purpose, the invention relates to a fabric, more particularly a compression fabric, comprising warp yarns and weft yarns, characterized in that the warp yarns are parallel to each other, at least one warp yarn in seven being such that, after any elongation of said yarn less than or equal to at least 30%, said yarn recovers its original shape before the elongation, each weft yarn comprising an elastane core covered entirely with a web, the web comprising filaments and / or fibers forming a continuous covering of the core.
[0011] The use of elastic warp yarns allows for elastic behavior of the fabric in the warp. Furthermore, the use of a weft yarn with an elastane core fully covered by a layer of fibers allows for the possibility of having an elastic weft fabric, particularly after a post-treatment stage. This is especially advantageous because the fabric is not elastic during weaving, which simplifies the process, but becomes elastic after the post-treatment stage, for the intended use.
[0012] According to other advantageous aspects of the invention, the fabric comprises one or more of the following characteristics, taken individually or in all technically possible combinations:
[0013] - said fabric has undergone a finishing step comprising steaming the fabric and / or impregnation of the fabric in water at a temperature greater than or equal to 75°C;
[0014] - at least one warp thread out of seven is a bare elastane thread, or a braided thread including an elastane core, or an elastane yarn obtained by air wrapping;
[0015] - each weft yarn consists of the elastane core and the fibre web;
[0016] - the tablecloth is made of viscose;
[0017] - the core of each weft yarn is made of elastane, more particularly is made of of at least one elastan filament;
[0018] - the core of each weft yarn has a count between 17 dtex and 500 dtex;
[0019] - the weft yarn sheet is wound helically around the core.
[0020] The invention also relates to a method for manufacturing a fabric according to the first aspect of the invention, comprising the following steps:
[0021] - supply of warp yarns and weft yarns, each weft yarn comprising a an elastane core entirely covered with a layer, the layer comprising filaments and / or fibers forming a continuous covering of the core,
[0022] - weaving of warp and weft yarns, the warp yarns being parallel relative to each other, at least one warp thread in seven during weaving being such that, after any elongation of said thread less than or equal to at least 30%, said thread recovers its original shape before the elongation.
[0023] According to other advantageous aspects of the invention, the manufacturing process according to the second aspect of the invention includes a fabric finishing step after the weaving step, the finishing step comprising steaming the fabric and / or impregnating the fabric with a solvent at a temperature greater than or equal to 75°C, more particularly at a temperature greater than or equal to 80°C.
[0024] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:
[0025] [Fig-1] [Fig.1] is a schematic representation of a simplified structure of a fabric according to a first embodiment of the invention,
[0026] [Fig.2] [Fig.2] is a partial three-dimensional representation of an example of a weft yarn,
[0027] [Fig.3] [Fig.3] is a schematic representation of a fabric weave according to a second embodiment of the invention,
[0028] [Fig.4] [Fig.4] is a cross-sectional representation perpendicular to the grid showing the warp threads of the fabric in [Fig.3],
[0029] [Fig. 5] [Fig. 5] is a schematic representation of a fabric weave according to a third embodiment according to the invention,
[0030] [Fig.6] [Fig.6] is a schematic representation of a fabric weave according to a fourth embodiment according to the invention,
[0031] [Fig.7] [Fig.7] is a schematic representation of a fabric weave according to a fifth embodiment according to the invention,
[0032] [Fig.8] [Fig.8] is a graph representing the evolution of the elongation of a wire compared to its tension during tests carried out under different vaporization conditions, and
[0033] [Fig.9] [Fig.9] is a graph representing the evolution of the average voltage experienced by the weft yarn during its insertion into the sheaf of a needle loom, said average tension corresponding to the average of such tension over forty cycles.
[0034] Examples of fabric according to the invention are shown in figures 1 and 3 to 7.
[0035] Fabric 10 is, for example, a compression fabric, more particularly for use medical.
[0036] The fabric 10 comprises warp yarns 12 and weft yarns 14.
[0037] The warp threads 12 are parallel to each other.
[0038] At least one warp thread in seven, here at least two warp threads in seven, is such that, after any elongation of said thread of less than or equal to at least 30%, said thread returns to its original shape before the elongation. Said warp thread(s) are referred to, in the remainder of the description, as elastic warp threads.
[0039] More specifically, herein "at least one / two warp yarns out of seven" means that for any group of seven adjacent warp yarns of the fabric, at least one / two warp yarn(s) have said characteristic.
[0040] Here, for any group of seven adjacent warp yarns of the fabric, two adjacent yarns of the group are elastic warp yarns, or the first yarn and the last yarn of the group are elastic warp yarns.
[0041] The other warp yarns here exhibit elasticity characteristics strictly less than an elongation of 30%. These other warp yarns are referred to in the following description as non-elastic warp yarns, as opposed to the so-called elastic warp yarns introduced previously.
[0042] The elastic warp yarn(s) is, for example, a bare elastane yarn, or a covered yarn comprising an elastane core, more particularly obtained by single or double covering, or an elastane yarn obtained by air covering.
[0043] The elastane yarn or core has, for example, a count between 44 dtex and 1500 dtex.
[0044] In the case of covering, the elastane core is surrounded by one or more cover yarns. The cover yarn(s) are, for example, made of natural textile material, for example cotton and / or wool, or of artificial textile material, for example viscose, or of synthetic textile material, for example polyamide and / or polyester, or of a mixture of the preceding textile materials.
[0045] Each blanket yarn has, for example, a count between 44 dtex and 400 dtex.
[0046] Elastic warp threads are, for example, identical to each other.
[0047] More particularly, here, each elastic warp yarn is a yarn obtained by double covering comprising an elastane core.
[0048] The core is, for example, an elastane filament, having, for example, a density between 300 dtex and 450 dtex.
[0049] The double covering is made with two covering threads, here in polyester.
[0050] The polyester yarn has, for example, a count between 150 and 175 dtex.
[0051] The polyester yarn comprises, for example, 48 filaments twisted once.
[0052] Non-elastic warp yarns are, for example, made of natural textile material, for example cotton and / or wool, or of artificial textile material, for example viscose, or of synthetic textile material, for example polyamide and / or polyester, or of a mixture of the preceding textile materials.
[0053] Each non-elastic warp yarn has, for example, a count between 44 dtex and 400 dtex.
[0054] Non-elastic warp threads are, for example, identical to each other.
[0055] More specifically, here, each non-elastic warp yarn is a polyamide yarn.
[0056] The polyamide yarn has, for example, a count between 75 and 320 dtex.
[0057] The polyamide yarn comprises, for example, 23 filaments twisted twice.
[0058] The weft threads 14 are parallel to each other.
[0059] An example of weft yarn 14 is shown in [Fig.2].
[0060] Each weft yarn 14 comprises an elastane core 16 entirely covered by a layer 18. The layer 18 comprises filaments and / or fibers forming a continuous covering of the core 16.
[0061] Each weft yarn 14 is, more particularly, made up of the elastane core 16 and the web 18.
[0062] The sheet 18 is wound helically around the core 16.
[0063] The layer 18 covers the entire core 16.
[0064] More particularly, the filaments and / or fibers of the layer 18 have a helical orientation around the core 16 within the layer 18. The weft yarn is of the CoreSpun type.
[0066] The core 16 of each weft yarn is made of elastane.
[0067] Elastane is natural or synthetic.
[0068] The core 16 of each weft yarn is made up of at least one filament, here continuous, of elastane.
[0069] More specifically, here, the core 16 of each weft yarn consists of a single continuous filament.
[0070] The core 16 of each weft yarn has a count between 17 dtex and 500 dtex.
[0071] The layer 18 is, for example, formed from filaments and / or discontinuous fibers on the wire length.
[0072] The tablecloth 18 is, for example, made of natural textile material, for example cotton and / or wool, or of artificial textile material, for example viscose, or of synthetic textile material, for example polyamide and / or polyester, or of a mixture of the preceding textile materials.
[0073] More specifically, here, tablecloth 18 is made of viscose.
[0074] More particularly here, each weft yarn has an elastane filament, having a count of 44 dtex, with a viscose web.
[0075] Each weft yarn has, for example, an overall count of between 30 and 40 Nm, that is to say that between 30 and 40 meters of a weft yarn weigh one gram.
[0076] Its elongation at break is between 15% and 18%.
[0077] Its breaking strength is greater than or equal to 250 cN, more particularly to 350 cN.
[0078] The warp yarns 12 and the weft yarns 14 are here woven according to a weave, several examples of which will be described later.
[0079] The fabric has, for example, a number of warp threads per centimeter between 40 and 60.
[0080] The fabric has, for example, a number of weft threads, therefore of weft yarns, per centimeter between 15 and 21.
[0081] In a first example, shown in [Fig.1], the weave is similar to a plain weave, but in which two weft yarns 14 are consecutively woven by lifting the even yarns of the warp, then two weft yarns by lifting the odd yarns of the warp, and so on two by two.
[0082] A second example of armor is shown in [Fig.3].
[0083] The armor is repeated here on seven warp threads ib i2, i3, i4, i5, i6, i7 and four weft threads Tb T2, T3, T4.
[0084] The pattern of the structure will thus be described for seven warp threads and four weft threads, this pattern being repeated on the plain weave on the surface of the fabric.
[0085] A cross-sectional representation perpendicular to the weft wires 14 showing the corresponding warp wires of the weave is shown in [Fig.4].
[0086] The weft threads are as described above.
[0087] The weft threads are identical to each other.
[0088] Two warp threads ib i2sur sept are elastic warp threads as described previously.
[0089] The elastic warp threads are identical here.
[0090] The elastic warp threads are adjacent here.
[0091] The other five warp yarns i3, i4, i5, i6, i7 out of seven are non-elastic warp yarns as described previously.
[0092] Non-elastic warp threads are, for example, identical to each other.
[0093] For the remainder, the elastic warp yarns are the first and second warp yarns, and the non-elastic warp yarns are the third to seventh warp yarns.
[0094] Each warp yarn has a first side and a second side defined with respect to the fabric plane. The first sides of the warp yarns are all defined on the same side of the fabric plane.
[0095] Alternating at each row, the weft thread passes:
[0096] - either on the first side of the first warp wire ib on the first side of the second warp wire chain i2, the first side of the third warp thread i3, the second side of the fourth warp thread i4, the first side of the fifth warp thread i5, the second side of the sixth warp thread i6, and the first side of the seventh warp thread i7, and so on for the following warp threads,
[0097] - either on the second side of the first warp wire ib on the second side of the second wire of warp i2, the second side of the third warp wire i3, the first side of the fourth warp wire i4, the second side of the fifth warp wire i5, the first side of the sixth warp wire i6 and the second side of the seventh warp wire i7, and so on for the following warp wires.
[0098] The fabric has, for example, a number of warp threads per centimeter between 40 and 60.
[0099] The fabric has, for example, a number of weft threads, therefore of weft yarns, per centimeter between 12 and 25.
[0100] The surface mass of the fabric is, for example, between 300 and 450 g / m2.
[0101] A third example of armor is shown in [Fig.5].
[0102] The weave is repeated here on seven warp threads i2, i3, i4, i5, i6, i7 and four weft threads Tb T2, T3, T4.
[0103] The pattern of the structure will thus be described for seven warp threads and four weft threads, this pattern being repeated on the plain weave on the surface of the fabric.
[0104] The weft yarns are as described above.
[0105] The weft yarns are identical to each other.
[0106] Two warp wires ib i2sur sept are elastic warp wires as described previously.
[0107] The elastic warp threads are identical here.
[0108] The elastic warp threads are here adjacent.
[0109] The other five warp yarns i3, i4, i5, i6, i7 out of seven are non-elastic warp yarns as described previously.
[0110] Non-elastic warp threads are, for example, identical to each other.
[0111] For the remainder, the elastic warp threads are the first and second warp threads, and the non-elastic warp threads are the third to seventh warp threads.
[0112] Each warp yarn has a first side and a second side defined with respect to the fabric plane. The first sides of the warp yarns are all defined on the same side of the fabric plane.
[0113] At a first row, the weft yarn Ti passes from the first side of the first warp yarn ii, from the first side of the second warp yarn i2, from the first side of the third warp yarn i3, from the second side of the fourth warp yarn i4, from the second side of the fifth warp yarn i5, from the second side of the sixth warp yarn i6 and from the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0114] At a second row consecutive to the first row, the weft yarn T2 passes from the second side of the first warp yarn ib to the second side of the second warp yarn i2, to the second side of the third warp yarn i3, to the first side of the fourth warp yarn i4, to the second side of the fifth warp yarn i5, to the first side of the sixth warp yarn i6 and to the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0115] At a third row consecutive to the second row, the weft yarn T3 passes from the first side of the first warp yarn ib to the first side of the second warp yarn i2, from the first side of the third warp yarn i3, from the second side of the fourth warp yarn i4, from the second side of the fifth warp yarn i5, from the second side of the sixth warp yarn i6 and from the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0116] At a fourth row consecutive to the third row, the weft yarn T4 passes from the second side of the first warp yarn ib to the second side of the second warp yarn i2, to the second side of the third warp yarn i3, to the second side of the fourth warp yarn i4, to the first side of the fifth warp yarn i5, to the second side of the sixth warp yarn i6 and to the first side of the seventh warp yarn i7, and so on for the following warp yarns.
[0117] These four rows of weft thread are repeated in the weave of the fabric.
[0118] The fabric has, for example, a number of warp threads per centimeter between between 45 and 50.
[0119] The fabric has, for example, a number of weft threads, therefore of weft yarns, per centimeter equal to 17.
[0120] The surface mass of the fabric is, for example, between 435 and 485 g / m2.
[0121] A fourth example of armor is shown in [Fig.6].
[0122] The armor is repeated here on seven warp threads ib i2, i3, i4, i5, i6, i7 and four weft threads Tb T2, T3, T4.
[0123] The pattern of the structure will thus be described for seven warp threads and four weft threads, this pattern being repeated on the plain weave on the surface of the fabric.
[0124] The weft yarns are as described above.
[0125] The weft threads are identical to each other.
[0126] Two warp threads ib i2sur sept are elastic warp threads as previously described.
[0127] The elastic warp threads are identical here.
[0128] The elastic warp threads are adjacent here.
[0129] The other five warp yarns i3, i4, i5, i6, i7 out of seven are non-elastic warp yarns as described previously.
[0130] Non-elastic warp threads are, for example, identical to each other.
[0131] For the remainder, the elastic warp yarns are the first and second warp yarns, and the non-elastic warp yarns are the third to seventh warp yarns.
[0132] Each warp yarn has a first side and a second side defined with respect to the fabric plane. The first sides of the warp yarns are all defined on the same side of the fabric plane.
[0133] At a first row, the weft yarn passes Tidu first side of the first warp yarn ib from the first side of the second warp yarn i2, from the first side of the third warp yarn i3, from the second side of the fourth warp yarn i4, from the first side of the fifth warp yarn i5, from the second side of the sixth warp yarn i6 and from the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0134] At a second row consecutive to the first row, the weft yarn T2 passes from the second side of the first warp yarn ib to the second side of the second warp yarn i2, to the second side of the third warp yarn i3, to the second side of the fourth warp yarn i4, to the second side of the fifth warp yarn i5, to the first side of the sixth warp yarn i6 and to the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0135] At a third row consecutive to the second row, the weft yarn T3 passes from the first side of the first warp yarn ib to the first side of the second warp yarn i2, to the first side of the third warp yarn i3, to the first side of the fourth warp yarn i4, to the second side of the fifth warp yarn i5, to the second side of the sixth warp yarn i6 and to the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0136] At a fourth row consecutive to the third row, the weft yarn T4 passes from second side of the first warp wire ib, second side of the second warp wire i2, second side of the third warp wire i3, second side of the fourth warp wire i4, second side of the fifth warp wire i5, second side of the sixth warp wire i6, and first side of the seventh warp wire i7, and so on for the following warp wires.
[0137] These four rows of weft thread are repeated in the weave of the fabric.
[0138] The fabric has, for example, a number of warp threads per centimeter between between 45 and 55.
[0139] The fabric has, for example, a number of weft threads, therefore of weft yarns, per centimeter equal to 17.
[0140] The surface mass of the fabric is, for example, between 450 and 500 g / m2.
[0141] A fifth example of armor is shown in [Fig.7].
[0142] The armor is repeated here on seven warp threads ib i2, i3, i4, i5, i6, i7 and four weft threads Tb T2, T3, T4.
[0143] The pattern of the structure will thus be described for seven warp threads and four weft threads, this pattern being repeated on the plain weave on the surface of the fabric.
[0144] The weft yarns are as described above.
[0145] The weft threads are identical to each other.
[0146] Two warp threads ib i2sur sept are elastic warp threads as previously described.
[0147] The elastic warp threads are identical here.
[0148] The elastic warp threads are here adjacent.
[0149] The other five warp yarns i3, i4, i5, i6, i7 out of seven are non-elastic warp yarns as described previously.
[0150] Non-elastic warp threads are, for example, identical to each other.
[0151] For the remainder, the elastic warp yarns are the first and second warp yarns, and the non-elastic warp yarns are the third to seventh warp yarns.
[0152] Each warp yarn has a first side and a second side defined with respect to the fabric plane. The first sides of the warp yarns are all defined on the same side of the fabric plane.
[0153] At a first row, the weft thread Tapasse of the first side of the first warp thread ib of the first side of the second warp thread i2, of the first side of the third warp thread i3, of the first side of the fourth warp thread Lj, of the second side of the fifth warp thread i5, of the second side of the sixth warp thread i6 and of the second side of the seventh warp thread i7, and so on for the following warp threads.
[0154] At a second row consecutive to the first row, the weft yarn T2 passes from the second side of the first warp yarn ib to the second side of the second warp yarn i2, to the second side of the third warp yarn i3, to the first side of the fourth warp yarn i4, on the second side of the fifth warp wire i5, on the first side of the sixth warp wire i6 and on the first side of the seventh warp wire i7, and so on for the following warp wires.
[0155] At a third row consecutive to the second row, the weft yarn T3 passes from the first side of the first warp yarn ib to the first side of the second warp yarn i2, to the first side of the third warp yarn i3, to the second side of the fourth warp yarn i4, to the second side of the fifth warp yarn i5, to the first side of the sixth warp yarn i6 and to the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0156] At a fourth row consecutive to the third row, the weft yarn T4 passes from the second side of the first warp yarn ib to the second side of the second warp yarn i2, to the second side of the third warp yarn i3, to the first side of the fourth warp yarn i4, to the first side of the fifth warp yarn i5, to the first side of the sixth warp yarn i6 and to the second side of the seventh warp yarn i7, and so on for the following warp yarns.
[0157] These four rows of weft thread are repeated in the weave of the fabric.
[0158] The fabric has, for example, a number of warp threads per centimeter between between 42 and 52.
[0159] The fabric has, for example, a number of weft threads, therefore of weft yarns, per centimeter between 16 and 17.
[0160] The surface mass of the fabric is, for example, between 440 and 490 g / m2.
[0161] After weaving, the resulting fabric exhibits elastic behavior in the direction of the warp, in particular by the use of elastic warp yarns, but substantially not very elastic in the direction of the weft.
[0162] The fabric is, for example, a so-called double-sided fabric, meaning that the two sides of the fabric are different from each other. In a particular embodiment, the warp yarns that are predominantly on the side intended to be in contact with a user's skin are, for example, more hydrophobic than those on the side intended to face outwards. This notably facilitates the wicking of water vapor and perspiration from the skin to the outside by capillary action.
[0163] The first embodiment, the second embodiment and the fifth embodiment correspond to so-called single-face fabrics, that is to say that the two faces of the fabric are identical to each other.
[0164] The third embodiment and the fourth embodiment correspond to double-sided fabrics.
[0165] In a particular embodiment, after weaving, the fabric has undergone a finishing step comprising steaming the fabric and / or impregnating the fabric by a solvent at a temperature of 75°C or higher, more particularly including a step of vaporizing the fabric and impregnating the fabric with a solvent at a temperature of 80°C or higher.
[0166] More specifically, the fabric is heated to a temperature of 80°C or higher for at least 10 minutes, while surrounded by water vapor. For example, the fabric is heated for at least four minutes at an intermediate heating temperature between 45°C and 60°C, and then for at least ten minutes at a maximum temperature of 80°C or higher, more specifically between 80°C and 98°C.
[0167] Then, the fabric is maintained at said maximum temperature for at least four minutes, the fabric being surrounded by water vapor.
[0168] Finally, the fabric cools down, for example with an ambient temperature between 50°C and 70°C.
[0169] Alternatively, the finishing step includes steaming at 100°C for two seconds, then impregnation in water at 90°C for nine seconds, then drying the fabric.
[0170] After the fabric has undergone a finishing step, the fabric also exhibits elastic behavior in the weft direction, in addition to the warp direction.
[0171] During finishing, the weft yarn web shrinks, which modifies the behavior of the weft yarn, and increases the elastic properties of the fabric in the weft direction.
[0172] The fabric 10 then exhibits elastic characteristics in the direction of the warp and in the direction of the weft.
[0173] Tests, the results of which are visible in [Fig.8], have been carried out on this subject.
[0174] Fig. 8 represents the tension F of a yarn, corresponding to a weft yarn of the fabric previously described, as a function of its elongation k for different vaporization conditions.
[0175] The tension F of the wire varies from 0.01 to 340 cN.
[0176] The tests were carried out under the following conditions:
[0177] - length of the test specimen between clamps: 100 mm,
[0178] - wire pre-tension: 0.01 cN, and
[0179] - traction speed: 1500 mm per minute.
[0180] A first tensile test is carried out on the wire which has not undergone any vaporization operation and is represented by a curve with triangles.
[0181] A second tensile test is carried out on the wire which has undergone a vaporization cycle at 80°C and is represented by a curve with squares.
[0182] The 80°C vaporization cycle consists, more specifically, of the following steps: maintaining the wire at an ambient temperature of 50°C for 5 minutes, raising the ambient temperature for 15 minutes up to 80°C with the addition of water vapor, maintaining the ambient temperature at 80°C for 5 minutes with the addition of water vapor, lowering the ambient temperature to 60°C in 15 minutes, then maintaining the temperature at 60°C for 7 minutes.
[0183] A third tensile test is carried out on the wire which has undergone a 95°C vaporization cycle and is represented by a curve with circles.
[0184] The 95°C vaporization cycle consists more particularly of the following steps: maintaining the wire at an ambient temperature of 50°C for 5 minutes, raising the ambient temperature for 15 minutes up to 95°C with the addition of water vapor, maintaining the ambient temperature at 95°C for 5 minutes with the addition of water vapor, lowering the ambient temperature to 75°C in 15 minutes, then maintaining the temperature at 60°C for 7 minutes.
[0185] It is noted that the yarn, corresponding to the weft yarn, exhibits increased elastic properties: its elongation increases for a given tension.
[0186] Thus, vaporizing a fabric comprising such a weft yarn increases its elastic properties in the direction of the weft.
[0187] Such a fabric is, for example, used in a medical compression device, for example a bandage, compression garment, orthosis or lumbar belt.
[0188] Such a fabric is particularly advantageous because it has reduced elastic properties in the weft direction during weaving, but increased after finishing.
[0189] During weaving, the tension T that the weft yarn undergoes is likely to vary significantly as shown in [Fig.9].
[0190] On the x-axis of [Fig.9], the value d from 0° to 180° corresponds to the passage of the needle through the swarm (made up of the two layers of warp threads), while the value from 180° to 360° corresponds to the return of the needle to its initial position.
[0191] The interval I2 corresponds to the insertion of the weft through the warp of the loom. The weft is carried by the needle, whose kinematics are controlled by a weft driver. Once the weft is inserted, and the needle reaches the end of its travel, the end of the weft is blocked (and is not cut).
[0192] The interval I3 corresponds to the return of the needle to its initial position. The weft is still carried by the needle.
[0193] The interval h is here the area where the comb strikes. The screen is at rest here before the insertion of the screen, which is held by the needle during the interval I2.
[0194] Thus, having low elasticity of the weft yarn during weaving makes it possible to limit any elongation of the yarn and therefore any deformation of the fabric that could be linked to this variation in yarn tension.
[0195] The maximum elongation of the warp fabric is greater than 10% of its length initial, more particularly greater than 100% of its initial length, that is to say that after any elongation of said fabric along the warp less than or equal to at least 10% (resp. 100%), said fabric recovers its original shape before the elongation.
[0196] In particular, the elastic warp yarns and the fabric structure are chosen to achieve such maximum warp elongation.
[0197] In a particular variant, the elastic warp yarns and the fabric structure are chosen so that the tension of the compression fabric, under its elongation at installation, for example of 30%, is between 10 cN / cm and 1000 cN / cm.
[0198] The maximum elongation of the fabric in the weft is between 10% and 100% of the initial width, that is to say that after any elongation of said fabric along the weft less than or equal to the maximum elongation, said fabric recovers its original shape before the elongation.
[0199] In particular, the elastic warp yarns, the weft yarn and the fabric structure are chosen to achieve such maximum weft elongation.
[0200] A process for manufacturing a fabric as described above will now be described.
[0201] The manufacturing process comprises the following steps:
[0202] - supply of warp yarns and weft yarns, as described above, and
[0203] - weaving of warp and weft yarns, the warp yarns being parallel relative to each other, at least one warp thread in seven during weaving being such that, after any elongation of said thread less than or equal to at least 30%, said thread recovers its original shape before the elongation.
[0204] The weaving is, for example, carried out in accordance with the embodiments described above.
[0205] The weaving is carried out on a loom.
[0206] In particular, the weaving of the fabric is carried out according to an example of a weave described above previously.
[0207] In a particular embodiment, the manufacturing process further includes a fabric finishing step after the weaving step, the finishing step being as described above.
[0208] Such a fabric is particularly advantageous because, after fabric finishing, it exhibits elastic properties along the warp and along the weft.
[0209] In addition, this fabric does not require a gauze, and can be easily produced on a conventional loom, with various weaves, thanks to its limited weft elasticity at the time of weaving.
Claims
Demands
1. Fabric (10), more particularly compression fabric, comprising warp yarns (12) and weft yarns (14), characterized in that the warp yarns (12) are parallel to each other, at least one warp yarn (12) out of seven being such that, after any elongation of said yarn less than or equal to at least 30%, said yarn recovers its original shape before the elongation, each weft yarn (14) comprising an elastane core (16) fully covered with a layer (18), the layer (18) comprising filaments and / or fibers forming a continuous covering of the core (16).
2. Fabric according to claim 1, wherein said fabric (10) has undergone a finishing step comprising steaming the fabric (10) and / or impregnating the fabric (10) in water at a temperature greater than or equal to 75°C.
3. Fabric according to claim 1 or 2, wherein at least one warp yarn (12) out of seven is a bare elastane yarn, or a wrapped yarn comprising an elastane core, or an elastane yarn obtained by air wrapping.
4. Fabric according to any one of claims 1 to 3, wherein each weft yarn (14) is made up of the elastane core (16) and the fibre web (18).
5. Fabric according to any one of claims 1 to 4, wherein the layer (18) is made of viscose.
6. Fabric according to any one of claims 1 to 5, wherein the core (16) of each weft yarn (14) is made of at least one elastane filament.
7. Fabric according to any one of claims 1 to 6, wherein the core (16) of each weft yarn (14) has a count between 17 dtex and 500 dtex.
8. Fabric according to any one of claims 1 to 7, wherein the web (18) of the weft yarn (14) is helically wound around the core (16).
9. A method for manufacturing a fabric (10) according to any one of claims 1 to 8, comprising the following steps: - supplying warp yarns (12) and weft yarns (14), each weft yarn (14) comprising an elastane core (16) entirely covered with a web (18), the web (18) comprising filaments and / or fibres forming a continuous covering of the core (16), - weaving of warp yarns (12) and weft yarns (14), the warp yarns (12) being parallel to each other, at least one warp yarn (12) out of seven during weaving being such that, after any elongation of said yarn less than or equal to at least 30%, said yarn recovers its original shape before the elongation.
10. A manufacturing method according to claim 9, comprising a fabric finishing step (10) after the weaving step, the finishing step comprising steaming the fabric (10) and / or impregnating the fabric (10) with a solvent at a temperature of 75°C or higher, more particularly at a temperature of 80°C or higher.