Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04B—KNITTING
  • D04B21/00—Warp knitting processes for the production of fabrics or articles not dependent on the use of particular machines; Fabrics or articles defined by such processes
  • D04B21/06—Patterned fabrics or articles
  • D04B21/08—Patterned fabrics or articles characterised by thread material
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2401/00—Physical properties
  • D10B2401/04—Heat-responsive characteristics
  • D10B2401/041—Heat-responsive characteristics thermoplastic; thermosetting

Definitions

• the present invention relates to the technical field of knitted textiles with elastic warp stitches, in particular made of polyester(s), the use of said knitted textiles, as well as articles of clothing comprising such knitted textiles.
• the present invention also relates to methods of manufacturing such knitted textiles.
• Elastic knitted textiles in particular for the practice of a sport, for example swimsuits, generally comprise elastane in combination with polyester or polyamide, the elastane possibly representing approximately 20% to 35% by mass of an elastic textile.
• Elastane, based on polyurethane is difficult to recycle, especially when combined with polyamides or polyesters which are materials of a different chemical nature. It is not possible to separate the interwoven threads of a textile component in order to recycle the different materials individually.
• these materials are not chemically compatible with each other, and therefore cannot be recycled together on an industrial scale in a profitable manner.
• these elastic knitted textiles resist chlorine and seawater if they are intended to be used in bathing suits or generally in articles of clothing in contact with seawater or chlorinated water.
• JP 2005/179886 thus proposes a textile component implementing a two-component yarn comprising a heat-shrinkable polymer component, in particular comprising polyethylene terephthalate and polytrimethylene terephthalate.
• a warp knit is knitted with a charmeuse weave. The average elongation obtained in the vertical direction and in the horizontal direction is indicated as being 78%. However, this knit does not have sufficient elasticity for sports applications.
• the subject of the present invention is thus an elastic warp knit, in particular made of polyester(s), which can be easily recycled, in particular not requiring separation of the various materials of which it is composed.
• the subject of the present invention is advantageously a warp knit fabric that is resistant to chlorine and to sea water.
• the present invention advantageously relates to a warp knit whose elasticity is markedly improved.
• the present invention also relates to a method of manufacturing such a warp knitted fabric.
• the subject of the present invention is a warp-knitted textile comprising columns of stitches and rows of stitches, and advantageously comprising:
• the mesh pattern selected in the present invention makes it possible to obtain a knitted fabric with warp stitches having significantly improved elasticities, in particular multiplied by more than two in the direction of the rows of stitches (also designated in the present text by weft direction) for reversed double knit weaves, in particular with closed or open stitches.
• the knitted textile according to the invention is a knitted textile according to an inverted double knit weave, with closed or open stitches, preferably with closed stitches.
• the knitted textile comprises several A threads and several B threads.
• yarn B is understood to mean a two-component yarn that said yarn B comprises, in particular essentially consists of, a first polymer component and a second polymer component.
• the two-component yarn(s) B comprises/comprises a first polymer component, in particular non-shrunk, more particularly non-heat-shrunk, and a second polymer component, in particular shrunk, more particularly heat-shrunk.
• the yarn(s) B may/may be one or more multifilament yarn(s), in particular flat or textured, more particularly textured.
• first and second polymeric components of yarn B are joined together inside each filament of said multifilament yarn B.
• Said at least one yarn B may comprise (or consist essentially of) filaments, each of the filaments of which is of the core-mantle (or also called core-shell) type, or of the side-by-side type, preferably of the side-by-side type.
• the first polymer component can thus form the core or the mantle or one of the sides of the filament, the second polymer component forms the remainder of the filament.
• Yarn B may be, without limitation, the yarn marketed by The Lycra Company under the trademark T400® or T400 ecomade®. It is a multifilament yarn, preferably textured.
• the first component of yarn B preferably has a melting or softening temperature higher than the melting or softening temperature of the second polymer component of yarn B.
• the first component of said at least one yarn B preferably has a shrinkage temperature higher than the shrinkage temperature of the second polymer component B.
• the first polymer component is preferably different from the second polymer component.
• the first polymer component is a polyester, in particular recycled and/or biobased
• the second polymer component is a polyester, in particular recycled and/or biobased.
• Polyester is understood in the present text to mean any polymer (that is to say homopolymer, copolymer or terpolymer) comprising (essentially consisting of) an ester repeating unit.
• yarn B at least partially shrunk means that the yarn B comprises a part of its structure which is shrunk, in particular heat-shrunk. Said retracted part, in particular extending over the length of the wire B, has undergone a dimensional shrinkage.
• the wire(s) B at least partially retracted is/are one or more wire(s) B comprising (each) a crimp or an undulation, in particular helical, repeated over its/their length, in particular obtained following heating of the wire(s) B or by any other technically equivalent means.
• a part of the yarn B (in particular extending over the length of one or more filament(s)) has undergone a dimensional shrinkage obtained by heating or by any other technically equivalent means.
• the ratio by mass of first polymer component of said at least one thread B: second polymer component of said at least one thread B is from 50:50 to 85:15, in particular from 60:40 to 75:25, more particularly from 60:25 to 70:35, for example approximately 68:approximately 32.
• a mass ratio component X: component Y in a given object ranging from a: b to c: d means that the mass fraction of component X in said object is greater than or equal to a% and less than or equal to c%, and that the mass fraction of component Y in said object is greater than or equal to b% and less than or equal to d%.
• the yarn(s) A is/are preferably one or more multifilament yarn(s) or one or more yarn(s) spun from fibers, preferably one or multifilament yarn(s), especially flat(s) or textured yarn(s), more preferably textured yarn(s).
• the thread(s) A a thread A may/may comprise one or more polymer material(s) chosen from: polyamides, such as polyamide 6 or 66; polypropylenes, such as polypropylene, polyethylene; polyesters, such as polyethylene (PET), and polybutylene terephthalate; optionally said material(s) is/are recycled and/or biosourced.
• polyamides such as polyamide 6 or 66
• polypropylenes such as polypropylene, polyethylene
• polyesters such as polyethylene (PET), and polybutylene terephthalate
• PET polyethylene
• the yarn(s) A may/may be one or more monocomponent yarn(s) or one or more multicomponent yarn(s), in particular one or more bicomponent yarn(s).
• said at least one yarn A is a single-component yarn (ie it comprises a single polymer component).
• Yarn A may be an untextured yarn (that is to say a flat yarn, in particular called FDY for Full Drawn Yarn in English) or textured (in particular DTY for drawn texturized yarn in English).
• the knitted textile may further comprise one or more additional yarn(s).
• the additional yarn(s) may/may be one or more yarn(s) spun from fibers or one or more multifilament yarn(s), in particular flat(s) or textured(s).
• the said additional yarn(s) may/may be one or more monocomponent or multicomponent yarn(s), in particular bicomponent(s).
• said additional yarn(s) is/are one or more single-component yarn(s).
• the additional yarn(s) may comprise one or more polymer material(s) chosen from: polyamides, such as polyamide 6 or 66; polypropylenes, such as polypropylene, and polyethylene; polyesters, such as polyethylene (PET), and polybutylene terephthalate (PBT); cellulose, such as cotton; in at least partially regenerated cellulose, such as viscose; optionally said material(s) is/are recycled and/or biosourced.
• polyamides such as polyamide 6 or 66
• polypropylenes such as polypropylene, and polyethylene
• polyesters such as polyethylene (PET), and polybutylene terephthalate (PBT)
• cellulose such as cotton
• in at least partially regenerated cellulose, such as viscose optionally said material(s) is/are recycled and/or biosourced.
• the ratio of the mass (in yarn(s) A and in yarn(s) B) to the total mass of the knitted textile is greater than or equal to 60%, preferably greater than or equal to 70% or 80% or 85% or 95%.
• the knitted textile consists essentially of yarn(s) A, and yarn(s) B.
• the knitted textile preferably comprises a back face and a face face.
• the yarn(s) A is/are knitted on the right side.
• the yarn(s) B is/are knitted on the reverse side.
• the knitted textile comprises one or more yarn(s) A and one or more yarn(s) B knitted repeatedly over two columns of stitches and over two rows of stitches.
• the knitted textile comprises several columns of stitches, in particular corresponding to the longitudinal direction or to the warp direction of the knitted textile, and several rows of stitches, in particular corresponding to the transverse or weft direction of the knitted textile.
• the knitted textile therefore comprises yarns A and yarns B.
• the knitted textile has a surface density greater than or equal to 100 g/m 2 , more preferably greater than or equal to 150 g/m 2 or 180 g/m 2 or 190 g/m 2 or 200 g/m 2 .
• the knitted textile has a basis weight less than or equal to 350 g/m 2 , more preferably less than or equal to 300 g/m 2 or 280 g/m 2 or 260 g/m 2 or 250 g/m 2 or 240 g/m 2 or 230 g/m 2 .
• the ratio of the mass of yarn(s) A to the total mass of the knitted textile is greater than or equal to 30%, preferably greater than or equal to 35% or 40% or 45% or 50%, more preferably approximately equal to 52% +/- 1%.
• the ratio of the mass of yarn(s) A to the total mass of the knitted textile is less than or equal to 80%, preferably less than or equal to 70% or 65% or 60% or 55%.
• the ratio of the mass of yarn(s) B to the total mass of the knitted textile is greater than or equal to 30%, preferably greater than or equal to 35% or 40% or 45%, more preferably approximately equal to 48% to +/-1%.
• the ratio of the mass of yarn(s) B to the total mass of the knitted textile is less than or equal to 80%, preferably less than or equal to 70% or 60% or 55% or 50%.
• a mesh bar is equivalent to a guide bar.
• the mesh bar supporting wire B works from right to left
• the mesh bar supporting wire A works from left to right.
• This arrangement makes it possible to improve the balancing of the binding between the yarns A and B, and avoids the problems of straight yarns, in particular that the knitted textile does not twist.
• This arrangement also makes it possible to increase the mass proportion of thread(s) B.
• yarn A is knitted according to a stitch pattern reversed to the stitch pattern of yarn B.
• the stitch pattern of said at least one thread A is symmetrical to the stitch pattern of said at least one thread B.
• said at least one yarn A is knitted according to a stitch pattern chosen from: 1-0/1-2//; 1-2/1-0//; 0-1/2-1//; and 2-1/0-1//, preferably 1-0/1-2// and 0-1/2-1//; more preferably 1-0/1-2//.
• said at least one yarn B is knitted according to a stitch pattern chosen from: 1-0/1-2//; 1-2/1-0//; 0-1/2-1//; and 2-1/0-1//, preferably 2-1/0-1// and 1-2/1-0//, more preferably 1-2/1-0//.
• the "//" sign represents the end of the stitch pattern ratio in the prior art, and each pair of x-y digits represents a stitch.
• said at least one yarn A comprises a polymer component made of polyester
• said at least one yarn B comprises two polymer components each made of polyester.
• This arrangement promotes the recyclable nature of the knitted textile according to the invention.
• yarn B comprises polyethylene terephthalate or polybutylene terephthalate, and polytrimethylene terephthalate.
• the first component of yarn B is polyethylene terephthalate or polybutylene terephthalate.
• the second component of yarn B is polytrimethylene terephthalate.
• yarn A is a multifilament yarn, having a linear density greater than or equal to 10 dtex and less than or equal to 500 dtex, preferably less than or equal to 200 dtex, more preferably greater than or equal to 10 dtex and less than or equal to 100 dtex.
• said at least one yarn A has a linear density greater than or equal to 30 dtex and less than or equal to 80 dtex, more preferably greater than or equal to 40 dtex and less than or equal to 70 dtex, in particular from 50 dtex to 60 dtex.
• said at least one yarn A comprises a number of filaments greater than or equal to 10 and less than or equal to 100, more preferably greater than or equal to 40 and less than or equal to 90, in particular from 65 to 85.
• said at least one yarn B is a multifilament yarn, having a linear density greater than or equal to 10 dtex and less than or equal to 200 dtex, at 100 dtex.
• said at least one yarn B has a linear density greater than or equal to 30 dtex and less than or equal to 80 dtex, more preferably greater than or equal to 40 dtex and less than or equal to 70 dtex, in particular greater than or equal to 50 dtex and less than or equal to 60 dtex.
• said at least one yarn B comprises a number of filaments greater than or equal to 10 and less than or equal to 100, more preferably greater than or equal to 20 and less than or equal to 40, in particular greater than or equal to 25 and less than or equal to 35.
• the knitted textile has, in the direction of the rows of stitches, an elongation at break greater than or equal to 100%, preferably greater than or equal to 150%, more preferably greater than or equal to 200%.
• the elongation at break obtained is very high, and significantly improved compared to that obtained for a charmeuse (stitch pattern) for example.
• the knitted textile has, in the direction of the columns of stitches, an elongation at break greater than or equal to 75%, preferably greater than or equal to 90%.
• the knitted textile has in the direction of the rows of stitches an elongation, under a force of 35 daN, greater than or equal to approximately 100%, preferably greater than or equal to 130%, more preferably greater than or equal to 140% and less than or equal to 160%.
• the knitted textile has in the direction of the columns of stitches an elongation, under a force of 35 daN, greater than or equal to approximately 30%, preferably greater than or equal to 35% or 45%, more preferably greater than or equal to 40% and less than or equal to 60%.
• the elongation obtained in the direction of the columns of stitches is less than that obtained in the weft direction, nevertheless it is high enough to obtain a knitted textile whose elasticity is markedly improved compared to the elastic knitted textile of the state of the art not comprising elastane.
• Elongation at break and elongation under a given load can be determined using ISO 3934-1, dated 2013, entitled "Textiles — Properties of fabrics in tension — Part 1: Determination of maximum force and elongation at maximum force by the tape method".
• the tests can be carried out with an MTS dynamometer, the pulling speed being 100 mm/min.
• the knitted textile has a number of columns of stitches per 10 mm greater than or equal to 15, or to 20.
• the knitted textile has a number of rows of stitches per 10 mm greater than or equal to 20, or 25, preferably greater than or equal to 30 or 35.
• the ratio of the mass of yarn(s) A to the total mass of the knitted textile is greater than or equal to 40% and less than or equal to 60%.
• the ratio of the mass of yarn(s) A to the total mass of the knitted textile is greater than or equal to 45% and less than or equal to 55%.
• the ratio of the mass of yarn(s) B to the total mass of the knitted textile is greater than or equal to 40% and less than or equal to 60%.
• the ratio of the mass of yarn(s) B to the total mass of the knitted textile is greater than or equal to 45% and less than or equal to 55%.
• the subject of the present invention is, according to a third aspect of the invention, an article of clothing, in particular for the practice of sport, comprising a knitted textile according to any one of the variant embodiments with reference to the first aspect of the invention.
• the article of clothing comprises a back face and a front face corresponding respectively to the back face and to the front face of the knitted textile.
• the article of clothing is an elastic article of clothing, in particular an article fitted close to the body. It is understood by elastic article of clothing that said article of clothing is elastic in at least one direction, for example horizontal or vertical or optionally both.
• the article of clothing can be used in numerous sports, such as the following sports cited without limitation: water sports (swimming, surfing, etc.), fitness, running.
• the article of clothing has a horizontal direction and a vertical direction corresponding respectively to the weft direction and to the warp direction of the knitted textile.
• the horizontal direction is substantially perpendicular to the vertical direction.
• the subject of the present invention is, according to a fourth aspect of the invention, a process for manufacturing a knitted textile, in particular according to any one of the variant embodiments with reference to the first aspect of the invention, comprising the steps:
• At least one yarn A with a guide bar A working on two columns of stitches at least one yarn B with a guide bar B working on two columns of stitches, the guide bars A and B working in opposition, to obtain an intermediate knitted textile
• said at least one yarn B is a two-component yarn comprising a shrinkable polymer component, in particular heat-shrinkable;
• a finishing treatment of the intermediate knitted textile in particular comprising a washing step (for example a de-sizing step) and/or a dyeing step;
• the finishing step comprises a washing step and/or a dyeing step, for example with a jet dyeing machine, in particular the heating temperature during dyeing is for example 120°C to 135°C.
• the dyeing is carried out with one or more dispersed dye(s).
• the step of activating the retraction of the retractable polymer component, in particular of the second polymer component of said at least one yarn B comprises passing the intermediate knitted textile over a drying ream, for example referred to as a stenter, in particular at a temperature ranging from 150 ° C to 180 ° C, for example 170 ° C, for at least one second, in particular for at least 30 seconds, for example about 60 seconds.
• a drying ream for example referred to as a stenter
• the knitted textile is wet before the shrinking step, for example due to the prior finishing treatment if no drying has been carried out and/or even by the application of water to said intermediate knitted textile (for example impregnation or spraying of water).
• the warp knitting machine is a warp or raschel knitting machine.
• the gauge of the knitting machine is greater than or equal to E24, preferably greater than or equal to E28 or E30.
• the gauge is greater than or equal to E24 and less than or equal to E40, more particularly greater than or equal to E28 and less than or equal to E40.
• the letter E designates the number of needles for an English inch.
• the gauge of the knitting loom is thus understood in the present text to mean the number of needles supported by the needle bed of the knitting loom for 25.4 mm (ie 1 inch).
• E24 means for example that the needle bed of the knitting machine has 24 needles per inch.
• guide bar A is fully threaded.
• guide bar B is fully threaded.
• the knitting machine used in the invention can be a circular knitting machine or a flat knitting machine.
• the warp knitted fabric may be a substantially planar knitted panel or a knitted tube.
• guide bar A supporting yarn A has a movement chosen from: 1-0/1-2//; 1-2/1-0//; 0-1/2-1//; and 2-1/0-1//, preferably 1 -0/1-2// and 0-1/2-1//; more preferably 1 -0/1-2//.
• the guide bar B supporting the yarn B has a movement chosen from: 1-0/1-2//; 1-2/1-0//; 0-1/2-1//; and 2-1/0-1//, preferably 2-1/0-1// and 1-2/1-0//, more preferably 1-2/1-0//.
• the knitted textile is advantageously knitted with two guide bars (also referred to herein as mesh bars), each supporting a thread.
• the guide bars each have a movement defined above according to the stitch patterns and repeated over the entire width of the knitted textile, and according to the desired length.
• the knitted fabric comprises multiple columns of stitches and multiple rows of stitches.
• FIG. 1 shows the stitch pattern of a first example of a knitted textile according to the invention
• Figure 2 schematically shows the first example of a knitted textile obtained by knitting the stitch pattern shown in Figure 1;
• Figure 3 shows the stitch pattern of a second example of a knitted textile according to the invention
• Figure 4 schematically shows the second example of knitted textile obtained by knitting the stitch pattern shown in Figure 3;
• Figure 5 shows the stitch pattern of a first comparative example of a knitted textile
• Figure 6 schematically shows the first comparative example of a knitted textile obtained by knitting the stitch pattern shown in Figure 5;
• Figure 7 shows the stitch pattern of a second comparative example of knitted textile
• Figure 8 schematically shows the second comparative example of a knitted textile obtained by knitting the stitch pattern shown in Figure 7.
• Figure 1 shows the stitch pattern of a first example of knitted textile 10 according to the invention shown schematically in Figure 2.
• the knitted fabric 10 is knitted on a warp knitting machine with two stitching bars, preferably a Karl Mayer type HKS2 loom.
• the gauge of the knitting machine is preferably E32.
• the first meshing bar 12 supports a thread A 13 and works on two columns of stitches according to the movement 1-0/1-2//, in particular the stitches are closed knit stitches.
• Yarn A 13 is preferably a multifilament yarn made of polyester, in particular polyethylene terephthalate (in particular recycled and/or biosourced), more particularly 55 dtex with 72 filaments and textured.
• the first mesh bar 12 is the front mesh bar so that the yarn A is knitted on the face side of the knitted textile 10.
• the second stitching bar 14 supports the yarn B 15 and works on two columns of stitches according to the movement 1-2/1-0//, in particular the stitches are closed knit stitches.
• Yarn B 15 is preferably a two-component yarn comprising polyethylene terephthalate and polytrimethylene terephthalate (in particular according to the weight ratio 68:32), in particular of 55 dtex with 35 filaments, in particular under the reference T400ecomade® marketed by The Lycra Company.
• the second mesh bar 14 is the rear mesh bar so that the yarn B is knitted on the reverse side of the knitted textile 10.
• the mesh bar 14 works in opposition and inverted manner with the mesh bar 12.
• the knit stitches formed by the mesh bar 12 are reversed with respect to the knit stitches formed by the mesh bar 14. opposite to the direction in which the meshing bar 14 works.
• the mesh bar 12 works from left to right while the mesh bar 14 works from right to left.
• the stitch bars 12 and 14 repeat their respective stitch patterns across the width of the knitted fabric 10 and according to the desired length so that the yarns A and B are knitted repeatedly according to the width and length of the knitted fabric 10.
• the knitted textile 10 is unknit, there are several A threads and several B threads.
• each meshing bar 12 and 14 is full, that is to say leaves no empty position.
• the partial withdrawal of the yarns B from the knitted textile is then activated, in particular by heating, for example at 170° C. for 60 seconds on a heating ream, so that the yarn B 15 is partly (thermo) shrunk, in particular the PTT is thermally activated and shrinks compared to the PET which remains stable.
• the yarn B 15 thus develops a crimp or a helical wave, thus conferring elasticity on the knitted textile 10.
• the elasticity of the knitted textile is advantageously developed after its knitting.
• the knitted textile prior to heating the knitted textile to activate the elasticity of yarn B, the knitted textile can undergo a finishing treatment in order to dye it for example.
• the ratio of the mass of yarn(s) A 13 to the total mass of the knitted textile 10 is approximately 52% in this specific example.
• the ratio of the mass of yarn(s) B 15 to the total mass of the knitted textile 10 is approximately 48% in this specific example.
• the knitted textile has a warp direction C or longitudinal L, and a weft direction T or transverse t, represented in FIGS. 2, 4, 6 and 8.
• the knitted textile 10 obtained has in this specific example: a surface density of 210 g/m 2 , approximately 96 rows of stitches per inch, approximately 56 columns of stitches per inch, an elongation at break in the warp direction (that is to say columns of stitches) of 111% and weft (i.e. rows of stitches) 236%, warp elongation 53% under 35N force/load, weft elongation 144% under 35N force/load.
• the knitted textile 10 has excellent elastic properties allowing it to be used in the manufacture of an article of clothing, and this advantageously by being essentially made up of polyesters, which facilitates the recycling of the knitted textile.
• Figure 3 shows the stitch pattern of a second example of knitted textile 20 according to the invention shown schematically in Figure 4.
• the knitted textile 20 is knitted on a warp knitting machine with two stitching bars, preferably a Karl Mayer type HKS2 loom.
• the gauge of the knitting machine is preferably E32.
• each mesh bar 22 and 24 is full, that is to say leaves no empty position.
• the first meshing bar 22 supports an A thread 23 and works on two columns of stitches according to the 0-1/2-1// movement, in particular the stitches are open knit stitches.
• Yarn A 23 is preferably a multifilament yarn made of polyester, in particular of polyethylene terephthalate (in particular recycled), more particularly of 55 dtex with 72 filaments and textured.
• the first stitching bar 22 is the front stitching bar so that the thread A 23 is knitted on the face face of the knitted textile 20.
• the second stitching bar 24 supports the yarn B 25 and works on two columns of stitches according to the 2-1/0-1// movement, in particular the stitches are open knit stitches.
• Yarn B 25 is preferably a two-component yarn comprising polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT) (in particular according to a weight ratio of 68:32), in particular of 55 dtex with 35 filaments, in particular under the reference T400ecomade® marketed by The Lycra Company.
• the second mesh bar 24 is the rear mesh bar so that the yarn B 25 is knitted on the reverse side of the knitted textile 20.
• the mesh bar 24 works in opposition and in reverse with the mesh bar 22.
• the knit stitches formed by the mesh bar 22 are reversed with respect to the knit stitches formed by the mesh bar 24.
• the mesh bar 22 works in a direction opposite to the direction in which the mesh bar 24 works.
• mesh bar 22 works from left to right while mesh bar 24 works from right to left.
• the stitch bars 22 and 24 repeat their stitch pattern over the entire width of the knitted fabric 20 and according to the desired length so that the yarns A and B are knitted repeatedly according to the width and length of the knitted fabric 20.
• the partial withdrawal of the yarns B 25 from the knitted textile is then activated, in particular by heating, for example at 170° C. for 60 seconds on a heating ream (stenter), so that the yarn B 25 is partly (thermo) shrunk, in particular the PTT is thermally activated and shrinks compared to the PET which remains stable.
• Yarn B 25 thus develops crimp or helical waviness, thus imparting elasticity to knitted textile 20.
• the elasticity of the knitted textile is advantageously developed after it has been knitted.
• the knitted textile prior to heating the knitted textile to activate the elasticity of yarn B, the knitted textile can undergo a finishing treatment in order to dye it for example.
• the ratio of the mass of yarn(s) A 23 to the total mass of the knitted textile 20 is approximately 52% in this specific example.
• the ratio of the mass of yarn(s) B 25 to the total mass of the knitted textile 20 is approximately 48% in this specific example.
• the knitted textile 20 obtained has in this specific example: a basis weight of 218 g/m 2 , an elongation in the warp direction of 40% under a force/load of 35N, an elongation in the weft direction of 157% under a force/load of 35N.
• the knitted textile 20 has excellent elastic properties allowing it to be used in the manufacture of an article of clothing, and this advantageously by being essentially made up of polyesters, which facilitates the recycling of the knitted textile.
• the elasticity in the weft direction is further improved compared to the first example of knitted textile 10 but is slightly reduced in the warp direction.
• the knitted fabric 10 has the best balance between the elasticities in the weft and warp directions compared to the knitted fabric 20.
• Figure 5 shows the stitch pattern of a first comparative example of knitted textile 30 shown schematically in Figure 6.
• the knitted fabric 30 is knitted on a warp knitting machine with two stitch bars, preferably a Karl Mayer type HKS2 loom.
• the gauge of the knitting machine is preferably E32.
• each mesh bar is full, i.e. leaves no empty position.
• the first stitching bar 32 supports an A thread 33 and works on three columns of stitches according to the 1-0/2-3// movement, in particular the stitches are closed knit stitches.
• Yarn A 33 is preferably a multifilament yarn made of polyester, in particular of polyethylene terephthalate (in particular recycled), more particularly of 55 dtex with 72 filaments and textured.
• the first mesh bar 32 is the front mesh bar so that the yarn A 33 is knitted on the face face of the knitted textile 30.
• the second stitching bar 34 supports the yarn B 35 and works on two columns of stitches according to the movement 1-2/1-0//, in particular the stitches are closed knit stitches.
• Yarn B 35 is preferably a two-component yarn comprising polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT) (in particular according to a weight ratio of 68:32), in particular of 55 dtex with 35 filaments, in particular under the reference T400ecomade® marketed by The Lycra Company.
• the stitch pattern shown in Figure 5 corresponds to a charmeuse.
• the second mesh bar 34 is the rear mesh bar so that the yarn B 35 is knitted on the reverse side of the knitted textile 30.
• mesh bar 34 works in opposition to mesh bar 32.
• the partial withdrawal of the yarns B 35 from the knitted textile is then activated, in particular by heating, for example at 170° C. for 60 seconds on a heating ream (stenter), so that the yarn B 35 is partly (thermo) shrunk, in particular the PTT is thermally activated and shrinks compared to the PET which remains stable.
• Yarn B 35 thus develops crimp or helical waviness, thus imparting elasticity to knitted textile 30.
• the elasticity of the knitted textile is advantageously developed after it has been knitted.
• the ratio of the mass of yarn(s) A 33 to the total mass of the knitted textile 30 is approximately 56% in this specific example.
• the ratio of the mass of yarn(s) B 35 to the total mass of the knitted textile 30 is approximately 44% in this specific example.
• the knitted textile 30 obtained has in this specific example: a surface weight of 220 g/m 2 , an elongation in the warp direction of 56% under a force/load of 35N, an elongation in the weft direction of 83% under a force/load of 35N.
• the knitted fabric 30 has an elasticity 73% lower than the elasticity of the knitted fabric 10, and 89% lower than the elasticity of the knitted fabric 20.
• Yarns A and B thus develop a synergistic effect when they are knitted according to the stitch patterns of Figures 1 and 3 to improve elasticity.
• FIG. 8 represents the stitch diagram of a second comparative example of knitted textile 40 represented schematically in FIG. 7 and corresponding to example 2 of JP 2005/179886.
• the knitted fabric 40 is knitted on a warp knitting machine with two stitch bars.
• the gauge of the knitting machine is preferably E28.
• the first meshing bar 42 supports a yarn 43 and works on three columns of stitches according to the 1-0/2-3// movement, in particular the stitches are closed knit stitches.
• Yarn 43 is a 44 dtex36 filament PET multifilament yarn.
• the first mesh bar 42 is the front mesh bar so that the yarn 43 is knitted on the face side of the knitted textile 40.
• the second stitching bar 44 supports the yarn 45 and works on two columns of stitches according to the 1-2/1-0// movement, in particular the stitches are closed knit stitches.
• Yarn 45 is a two-component PET-based yarn from PTT (in a PTT:PET weight ratio of 50:50).
• Yarn 45 is a 44 dtex multifilament yarn for 36 filaments.
• the stitch pattern shown in Figure 7 corresponds to a charmeuse.
• the second stitch bar 44 is the rear stitch bar so that the yarn 45 is knitted on the reverse side of the knitted fabric 40.
• the ratio of the mass of yarn(s) 43 to the total mass of the knitted textile 40 is approximately 70% in this specific example.
• the ratio of the mass of yarn(s) 45 to the total mass of the knitted textile 40 is approximately 30% in this specific example.
• the knitted fabric 40 is described as having a basis weight of 224 g/m 2 , a horizontal/vertical elongation rate of 78% under a force of 17.7N. Knitted fabric 40 has an elasticity that is 85% lower than the elasticity of knitted fabric 10, and 100% lower than the elasticity of knitted fabric 20.
• the knitted fabrics 10 and 20 according to the invention have significantly improved elasticities, in particular in the weft direction, obtained due to the combination of the two meshing bars working in opposition and inverted manner on two columns of stitches with yarns A and B, yarn B being a two-component yarn whose elasticity is activated thermally and not mechanically or by virtue of its composition.
• the knitted textiles 10 and 20 are 100% by weight of polyesters. This arrangement facilitates their recycling in the manufacture of polyester articles because it is not necessary to separate the threads. Furthermore, it has been observed that these polyester yarns exhibit good resistance to chlorinated and salt water (100 hours in chlorinated water and 200 hours in chlorinated water) due in particular to the absence of elastane. In addition, the materials being of the same chemical nature, the dyeing of the knitted textiles 10 and 20 is facilitated.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Knitting Of Fabric (AREA)

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Citations (5)

• 2022
  • 2022-01-18 FR FR2200427A patent/FR3131926A1/fr active Pending
• 2023
  • 2023-01-17 TW TW112102100A patent/TW202346672A/zh unknown
  • 2023-01-17 WO PCT/EP2023/051033 patent/WO2023139073A1/fr active Application Filing
  • 2023-01-17 CN CN202380017522.XA patent/CN118574959A/zh active Pending

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