Anti-slip elastic yarn, denim fabric and spinning device

Abstract

The application discloses a kind of elastic yarns, jeans fabric and spinning jet device to prevent slide and pop, belong to textile field, the elastic yarn core includes cladding layer and yarn core, and yarn core contains spandex, yarn core includes fixedly connected together inner layer and outer layer, outer layer is vinylon, and inner layer is spandex, and spandex is periodically curved in wave shape or periodically curved in spiral shape in outer layer, and the melting point of cladding layer is higher than vinylon.The elastic yarn pre-stores curved spandex in yarn core, in the necessary washing process of producing jeans, due to the protection of vinylon, the oxidizing agent used in washing process is not easy to directly contact the inner layer of spandex, even if part of spandex is affected by oxidizing agent and shrinks, the pre-stored bending can offset this shrinkage, in the necessary drying process after washing, the outer layer of vinylon is partially melted, fills the gap left by pre-stored bending after spandex shrinkage and straightening, and after cooling, it is used as the connecting material between spandex and cladding layer again, so as to prevent the problem of slide and pop.

Description

Technical Field

[0001] This invention relates to an elastic yarn, denim fabric, and spinning device for preventing slippage, belonging to the textile field. Background Technology

[0002] Denim clothing, with its unique, retro twill distressed style, has been favored for over a century and has remained a staple in the fashion world, giving rise to an enduring denim culture. Denim clothing holds an irreplaceable position in the clothing market. After cutting and sewing, denim garments undergo a washing process (enzyme bleaching, chlorine bleaching, oxygen bleaching, manganese bleaching) to remove some of the indigo dye from the fabric surface, resulting in a myriad of faded styles. This fading and distressing technique is a crucial method for increasing the added value of denim clothing.

[0003] With social progress and economic development, traditional coarse-count pure cotton twill fabric can no longer meet market demands, and elastic denim clothing is increasingly favored. Using elastic yarns in the weft gives the fabric stretch, allowing for free movement during wear. However, after washing, the spandex at seams in some areas of denim clothing shrinks (both radially and axially), causing irregular bulges and other quality issues. This results in irreversible loss of elasticity and slippage, affecting both appearance and aesthetics. Slippage refers to the loss of friction between the spandex and the cotton fibers covering it, allowing them to slide relative to each other, resulting in a lack of elasticity despite the presence of spandex. While fading and distressing require washing, this process can easily cause localized slippage, especially at seams. This is the most significant factor hindering the development of elastic denim fabrics and a common key technical challenge in the denim industry. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides an elastic yarn that prevents slippage and can withstand conventional washing processes, and provides a spinning device for making the yarn, as well as denim fabric made from the yarn.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] In a first aspect, this application provides an elastic yarn for preventing slippage, comprising a covering layer and a core, wherein the core contains spandex, and the core comprises an inner layer and an outer layer fixedly connected together, wherein the outer layer is vinylon, the inner layer is the spandex, and the spandex is periodically bent in a wavy or spiral shape within the outer layer, and the melting point of the covering layer is higher than that of the vinylon.

[0007] After denim fabric is cut and sewn into denim garments, it needs to undergo a washing process to age it, and the water introduced by the washing process needs to be dried. The anti-slip elastic yarn provided in this application has pre-stored bent spandex in the yarn core. During the washing process, under the protection of vinylon, the oxidant used in the washing process is not easy to directly contact the inner spandex. Even if some spandex shrinks under the action of the oxidant, the pre-stored bend can offset this shrinkage. When drying, the outer vinylon partially melts and fills the gap left by the pre-stored bend after the spandex shrinks and straightens. After cooling, it is reused as the connecting material between the spandex and the covering layer, thereby preventing the slippage problem.

[0008] Furthermore, the coating layer is made of natural short fibers or chemical short fibers, which facilitates a tight bond between the vinylon and the vinylon during remelting and cooling.

[0009] Furthermore, in the wave-shaped periodic bending, the interval between repeating units is 10mm-200mm; in the spiral periodic bending, the interval between repeating units is 10mm-200mm.

[0010] This interval is designed to precisely offset the shrinkage of the spandex after washing, preventing excessive pre-existing bending that could lead to insufficient elasticity.

[0011] Furthermore, the yarn core is made in the following manner:

[0012] A spandex spinning solution is added to a spinneret, causing the spinneret to eject spandex from a first outlet; a vinylon spinning solution is added to the spinneret, causing the spinneret to eject vinylon from a second outlet; the second outlet surrounds the first outlet in a ring, so that the vinylon wraps around the spandex; the spandex ejected from the first outlet is intermittently blown before being wrapped by the vinylon, so that the spandex is blown to bend and swing before being wrapped.

[0013] Furthermore, in terms of the length ejected per unit time, the ejection velocity of the first outlet is greater than that of the second outlet.

[0014] Secondly, this application provides a spinning device for producing a yarn core as described in the first aspect, comprising an outer spinning solution tank, an inner spinning solution tank, and an air duct. The inner spinning solution tank is connected to an inner spinning solution conduit, and the end of the inner spinning solution conduit is provided with a central outlet. The outer spinning solution tank is connected to an annular outlet. The central outlet is located on the axis of the annular outlet and is recessed within the annular outlet according to the fiber travel direction. The end of the air duct is provided with an air nozzle, which faces the position between the central outlet and the annular outlet.

[0015] The central outlet corresponds to the first outlet mentioned above, and the annular outlet corresponds to the second outlet mentioned above. The duct intermittently supplies air so that the air nozzle intermittently blows the spandex sprayed from the central outlet, causing the spandex to swing and bend, and accelerating the solidification of the spandex as much as possible.

[0016] Furthermore, the spinning device further includes an outer spinning shell and an outer spinning inner liner. The outer spinning inner liner is disposed inside the outer spinning shell, and the gap between the lower end of the outer spinning inner liner and the lower end of the outer spinning shell forms the annular outlet. The upper end of the outer spinning shell is higher than the top of the outer spinning inner liner, and the portion of the outer spinning shell above the outer spinning inner liner forms the outer spinning liquid pool. A cavity is provided inside the outer spinning inner liner, and the cavity has a bottom opening. The inner spinning liquid pool is disposed outside the outer spinning shell. The inner spinning liquid conduit and the air duct pass through the outer spinning shell and the outer spinning inner liner and enter the cavity. The central outlet is located inside the cavity and aligned with the bottom opening. The air outlet is located inside the cavity and faces the position between the central outlet and the bottom opening.

[0017] Furthermore, the lower part of the outer spinning inner liner and the lower part of the outer spinning outer shell are conical with a taper of 30°-60°, which is beneficial for the vinylon to tightly wrap the spandex and for making a yarn core with a smaller overall diameter.

[0018] Furthermore, there are two air ducts, and the air outlets of the two air ducts are distributed on both sides of the central outlet. The central outlet and the two air outlets are on the same plane, and the two air outlets blow air in turn.

[0019] Furthermore, there are three or more air ducts, and the air outlets of the multiple air ducts are arranged in a circular array around the central outlet, with the multiple air outlets blowing air in turn.

[0020] Thirdly, this application provides a denim fabric using the anti-slip elastic yarn described in the first aspect as the weft yarn.

[0021] The beneficial effects of this invention are as follows: The elastic yarn for preventing slippage of this invention has pre-stored bent spandex in the yarn core. During the washing process necessary for the production of denim clothing, due to the protection of the vinylon, the oxidant used in the washing process is not easy to directly contact the inner spandex. Even if some spandex shrinks due to the action of the oxidant, the pre-stored bend can offset this shrinkage. In the necessary drying process after washing, the outer vinylon partially melts, filling the gap left by the pre-stored bend after the spandex shrinks and straightens. After cooling, it is reused as the connecting material between the spandex and the covering layer, thereby preventing the slippage problem.

[0022] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an elastic yarn for preventing slippage provided in an embodiment of this application.

[0024] Figure 2 This is a schematic diagram illustrating the manufacturing principle of a yarn core provided in an embodiment of this application.

[0025] Figure 3 This is a perspective view of a spinneret device provided in an embodiment of this application.

[0026] Figure 4 This is a schematic diagram of the structure of the air duct and the inner spinning solution conduit provided in the embodiments of this application.

[0027] Figure 5 This is a schematic diagram of the internal structure of a spinneret device provided in an embodiment of this application.

[0028] Figure 6 This is a cross-sectional view of a spinneret device provided in an embodiment of this application.

[0029] Figure 7 This is one of the top views of the air outlet distribution location provided in the embodiments of this application.

[0030] Figure 8 This is the second top view of the air outlet distribution location provided in the embodiments of this application.

[0031] Reference numerals: 11. Annular outlet; 12. Outer spinning solution pool; 13. Outer spinning shell; 14. Outer spinning inner liner; 141. Cavity; 142. Bottom opening; 17. Outer spinning solution conduit; 21. Inner spinning solution conduit; 28. Inner spinning solution pool; 29. ​​Central outlet; 3. Covering layer; 5. Air duct; 51. Air outlet; 6. Spandex; 7. Vinylon; 8. Spinneret. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0035] To address the issue of spandex becoming slippery after washing, existing technologies have researched new washing methods for denim fabrics. These methods aim to prevent slipperiness by altering the washing process and parameters. However, these methods have limited applicability and are only suitable for specific fabrics. Changing the fabric material necessitates readjusting the washing method and parameters, which is not conducive to continuous production.

[0036] Reference Figure 1 This application provides an elastic yarn to prevent slippage, including a covering layer 3 and a yarn core. The yarn core contains spandex and includes an inner layer and an outer layer fixedly connected together. The outer layer is vinylon 7 and the inner layer is spandex 6. The spandex 6 is periodically bent in a wavy or spiral shape in the outer layer. The melting point of the covering layer 3 is higher than that of vinylon.

[0037] The washing processes required for denim garment production include enzyme bleaching, chlorine bleaching, and oxygen bleaching. Among these, chlorine bleaching, oxygen bleaching, and manganese bleaching systems have strong oxidizing properties, which not only damage the dye structure but also affect the fiber structure. For spandex, the chlorine bleaching environment is the most demanding. Spandex undergoes shrinkage under chlorine bleaching, easily causing slippage and elasticity at the seams of the pants. Spandex shrinkage also easily causes unevenness in the fabric surface, severely affecting the appearance of the denim garment. The slippage and elasticity are equivalent to a loss of elasticity, making the seams prone to breakage after prolonged stretching during exercise.

[0038] In this embodiment, the spandex, protected by the outer low-melting-point vinylon, can resist some of the strong oxidizing environment during the washing process. Because the spandex has pre-existing flexibility, it can stretch to a greater length. Even if it shrinks due to strong oxidizing conditions, the longer spandex (pre-existing flexibility) can offset the shrinkage. This shrinkage is due to the spandex sliding relative to the covering layer. However, during the necessary drying process after washing, the outer low-melting-point vinylon partially melts, and after cooling, it re-fixes the spandex to the covering layer, giving the fabric excellent elasticity and effectively solving the slippage problem. Furthermore, this yarn can be used in ordinary washing processes without special adjustments to the washing process parameters.

[0039] Specifically, the coating layer is made of natural or chemical short fibers, which facilitates a tight bond between the vinylon and the vinylon during remelting and cooling. Short fibers refer to fibers with a length of less than 150 mm.

[0040] If too little pre-stored bend is applied, it will be insufficient to offset the shrinkage of the spandex during washing; if too much pre-stored bend is applied, it will result in high yarn elongation but poor resilience. Preferably, in wavy periodic bending, the interval between repeating units is 10mm-200mm; in spiral periodic bending, the interval between repeating units is 10mm-200mm. Taking wavy periodic bending as an example, the interval between repeating units refers to the distance between adjacent wave crests, which helps to avoid insufficient elasticity due to excessive pre-stored bend.

[0041] Reference Figure 2 The yarn core can be made in the following ways:

[0042] Spandex spinning solution is added to a spinneret to cause the spinneret to eject spandex from the first outlet; vinylon spinning solution is added to the spinneret to cause vinylon to eject from the second outlet; the second outlet surrounds the first outlet in a ring so that the vinylon wraps around the spandex; the spandex ejected from the first outlet is wrapped by the vinylon after intermittent blowing, so that the spandex is blown to bend and swing before being wrapped.

[0043] Based on the ejection length per unit time, the ejection velocity of the first outlet is greater than that of the second outlet.

[0044] The interval of the aforementioned repeating unit can be adjusted in two ways: first, by adjusting the duration and frequency of blowing; second, by adjusting the difference in ejection speed between the first outlet and the second outlet.

[0045] As an example, spandex spinning solution can be prepared by dissolving polyurethane resin in a polar solvent, such as tetrahydrofuran, stirring at 32°C-36°C, and then vacuum degassing to obtain spandex spinning solution.

[0046] The above process has produced the yarn core. To continue producing the elastic yarn that prevents slippage as described in this application embodiment, it is necessary to coat the surface of the yarn core with natural short fibers or chemical short fibers in the spinning machine used for spinning.

[0047] For the spinning device used to produce the aforementioned yarn core, please refer to... Figures 2 to 6 It includes an outer spinning solution tank 12, an inner spinning solution tank 28, and an air duct 5. The inner spinning solution tank 28 is connected to an inner spinning solution conduit 21. The end of the inner spinning solution conduit 21 is provided with a central outlet 29. The outer spinning solution tank 12 is connected to an annular outlet 11. The central outlet 29 is located on the axis of the annular outlet 11. According to the fiber travel direction, the central outlet 29 is recessed within the annular outlet 11. The end of the air duct 5 is provided with an air outlet 51. The air outlet 51 faces the position between the central outlet 29 and the annular outlet 11.

[0048] The central outlet 29 corresponds to the first outlet mentioned above, and the annular outlet 11 corresponds to the second outlet mentioned above. The air duct 5 delivers air intermittently so that the air nozzle 51 intermittently blows the spandex 6 sprayed from the central outlet 29, causing the spandex to swing and bend, and accelerating the solidification of the spandex as much as possible.

[0049] In some embodiments, the structure of the spinneret may be as follows: Figure 2 As shown, it includes a spinneret 8, on which multiple sets of spinneret holes are provided ( Figure 2 (Only one set is shown in the figure). Each set of spinnerets includes a central outlet 29 and an annular outlet 11. The top of the annular outlet 11 is connected to an outer spinning solution conduit 17, which is used to receive vinylon spinning solution. The fibers ejected from the central outlet 29 pass through the annular outlet 11 and are blown by the air blower 51 before passing through.

[0050] In a preferred embodiment, refer to Figures 3 to 6The spinning device includes an outer spinning shell 13 and an outer spinning inner liner 14. The outer spinning inner liner 14 is disposed inside the outer spinning shell 13. The gap between the lower end of the outer spinning inner liner 14 (described in the direction shown in the figure; in actual production, the spinneret orifice usually faces downwards) and the lower end of the outer spinning shell 13 forms an annular outlet 11. The upper end (described in the direction shown in the figure) of the outer spinning shell 13 is higher than the top of the outer spinning inner liner 14, and the portion of the outer spinning shell 13 that is higher than the outer spinning inner liner 14 forms the outer spinning inner liner. The spinning solution tank 12; a cavity 141 is provided inside the outer spinning inner liner 14, and the cavity 141 has a bottom opening 142; the inner spinning solution tank 28 is located outside the outer spinning outer shell 13, and the inner spinning solution conduit 21 and air duct 5 pass through the outer spinning outer shell 13 and the outer spinning inner liner 14 to enter the cavity 141. The central outlet 29 is located inside the cavity 141 and aligned with the bottom opening 142, and the air outlet 51 is located inside the cavity 141 and faces the position between the central outlet 29 and the bottom opening 142. This structure is conducive to the filling of the outer spinning solution in the annular outlet 11 and to the uniformity of the outer layer thickness of the yarn core.

[0051] Preferably, the lower part of the outer spinning inner liner 14 and the lower part of the outer spinning outer shell 13 are conical with a taper of 30°-60°, which is beneficial for the vinylon to tightly wrap the spandex and for making a yarn core with a smaller overall diameter.

[0052] In some embodiments, refer to Figure 7 There are two air ducts 5, with air outlets 51 located on either side of the central outlet 29. The central outlet 29 and the two air outlets 51 are on the same plane, and the two air outlets 51 blow air alternately. This structure and Figure 2 The structures shown are all spandex 6 that can be blown into a wave-like, periodically bent shape.

[0053] In other embodiments, there are three or more ducts 5, such as... Figure 8 A representative embodiment is a circular array of three or more air ducts 5 with air outlets 51 surrounding the central outlet 29. The multiple air outlets 51 blow air in turn, which can blow the spandex 6 into a spiral periodic bend.

[0054] Example 1

[0055] A denim fabric has 10S cotton yarn as the warp and 10S elastic yarn as the weft. The weft includes a covering layer and a core. The covering layer is made of cotton fiber, and the core includes an outer layer and an inner layer. The outer layer is made of vinylon, and the inner layer is made of spandex with a wavy, periodically bent shape. The interval between repeating units is 20mm. When this fabric is made into jeans and washed, there are no obvious unevenness at the seams. The elastic properties of the fabric are tested using the ASTM D3107 standard test method. The test results show that the elastic elongation is 56.8% and the elastic recovery rate is 96.4%.

[0056] Example 2

[0057] A denim fabric has 10S cotton yarn as the warp and 10S elastic yarn as the weft. The weft yarn includes a covering layer and a core. The covering layer is cotton fiber, and the core includes an outer layer and an inner layer. The outer layer is vinylon, and the inner layer is helically and periodically bent spandex. The interval between repeating units is 10mm. When this fabric is made into jeans and washed, there are no obvious unevenness at the seams. The elastic properties of the fabric are tested using the ASTM D3107 standard test method. The test results show that the elastic elongation is 62.8% and the elastic recovery rate is 95.3%.

[0058] Example 3

[0059] A denim fabric has 10S cotton yarn as the warp and 10S elastic yarn as the weft. The weft includes a covering layer and a core. The covering layer is cotton fiber, and the core includes an outer layer and an inner layer. The outer layer is vinylon, and the inner layer is helically and periodically bent spandex with a repeating unit interval of 5mm. When this fabric is made into jeans and washed, there are no obvious unevenness at the seams. The elastic properties of the fabric are tested using the ASTM D3107 standard test method, and the elastic elongation is found to be 69.3%, and the elastic recovery rate is 92.6%.

[0060] Comparative Example 1

[0061] A denim fabric has 10S cotton yarn as the warp and 10S elastic yarn as the weft. The weft includes a covering layer and a core. The covering layer is made of cotton fiber, and the core is made of spandex. When this fabric is made into jeans and washed, the seams become uneven. The fabric's elasticity is tested using the ASTM D3107 standard test method. The results show an elastic elongation of 49.5% and an elastic recovery rate of 89.8%.

[0062] Compared with Examples 1 and 2, Example 3 has a higher elastic elongation but a poorer elastic recovery rate. Comparing Examples 1, 2, and 3 with Comparative Example 1, it can be seen that the embodiments of this application can retain more length of spandex in the yarn, effectively solving the problem of spandex shrinkage during the washing process, which causes localized loss of elasticity in the fabric. This avoids unevenness at seams, allowing the fabric to maintain its aesthetic appeal and excellent elasticity.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An elastic yarn for preventing slippage, comprising a covering layer and a core, said core containing spandex, characterized in that, The yarn core includes an inner layer and an outer layer fixedly connected together. The outer layer is vinylon, and the inner layer is spandex. The spandex is periodically bent in a wavy or spiral shape within the outer layer. The melting point of the covering layer is higher than that of the vinylon. The yarn core is made in the following manner: A spandex spinning solution is added to a spinneret, causing the spinneret to eject spandex from a first outlet; a vinylon spinning solution is added to the spinneret, causing the spinneret to eject vinylon from a second outlet; the second outlet surrounds the first outlet in a ring, so that the vinylon wraps around the spandex; the spandex ejected from the first outlet is intermittently blown before being wrapped by the vinylon, so that the spandex is blown to bend and swing before being wrapped.

2. The anti-slip elastic yarn according to claim 1, characterized in that, The coating layer is made of natural short fibers or chemical short fibers.

3. The anti-slip elastic yarn according to claim 1, characterized in that, In the wave-shaped periodic bending, the interval between repeating units is 10mm-200mm; in the spiral periodic bending, the interval between repeating units is 10mm-200mm.

4. A spinning device for producing a yarn core as described in any one of claims 1 to 3, characterized in that, It includes an outer spinning solution tank (12), an inner spinning solution tank (28), and an air duct (5). The inner spinning solution tank (28) is connected to an inner spinning solution conduit (21). The end of the inner spinning solution conduit (21) is provided with a central outlet (29). The outer spinning solution tank (12) is connected to an annular outlet (11). The central outlet (29) is located on the axis of the annular outlet (11). According to the fiber travel direction, the central outlet (29) is recessed within the annular outlet (11). The end of the air duct (5) is provided with an air blower (51). The air blower (51) faces the position between the central outlet (29) and the annular outlet (11).

5. The spinneret according to claim 4, characterized in that, It also includes an outer spinning shell (13) and an outer spinning inner liner (14), the outer spinning inner liner (14) being disposed inside the outer spinning shell (13), the gap between the lower end of the outer spinning inner liner (14) and the lower end of the outer spinning shell (13) forming the annular outlet (11); the upper end of the outer spinning shell (13) is higher than the top of the outer spinning inner liner (14), the portion of the outer spinning shell (13) above the outer spinning inner liner (14) forming the outer spinning liquid pool (12); a cavity (141) is provided inside the outer spinning inner liner (14). The cavity (141) is provided with a bottom opening (142); the inner spinning solution pool (28) is located outside the outer spinning shell (13); the inner spinning solution conduit (21) and the air duct (5) pass through the outer spinning shell (13) and the outer spinning inner liner (14) and enter the cavity (141); the central outlet (29) is located in the cavity (141) and aligned with the bottom opening (142); the air outlet (51) is located in the cavity (141) and faces the position between the central outlet (29) and the bottom opening (142).

6. The spinneret according to claim 5, characterized in that, The lower part of the outer spinning inner liner (14) and the lower part of the outer spinning outer shell (13) are conical, with a taper of 30°-60°.

7. The spinneret according to claim 4, characterized in that, There are two air ducts (5). The air outlets (51) of the two air ducts (5) are distributed on both sides of the central outlet (29). The central outlet (29) and the two air outlets (51) are on the same plane, and the two air outlets (51) blow air in turn.

8. The spinneret according to claim 4, characterized in that, There are three or more air ducts (5), and the air outlets (51) of the multiple air ducts (5) are arranged in a circular array around the central outlet (29), and the multiple air outlets (51) blow air in turn.

9. A denim fabric, characterized in that, The elastic yarn for preventing slippage as described in any one of claims 1 to 3 is used as the weft yarn.

Images