Method for producing elastic yarn by melt spinning extrusion

Abstract

The present invention relates to a method for producing an elastic yarn (20) by melt spinning using a spinning device (1) comprising an extruder (2) and a spinneret pack (3) having at least one die (19). The method includes at least the following steps, namely, pre-cooling and stretching the yarn (20) at the outlet of the die (19), subsequently hot stretching the yarn (20), and then cold stretching the yarn (20). The present invention also relates to a textile containing such an elastic yarn and a facility for carrying out the above method.

Description

Technical Field

[0001] The present invention relates to a method for producing a recyclable elastic yarn, particularly an elastic yarn that can be used in the production of textiles and footwear.

Background Art

[0002] Elastic textiles have been known for many years. For example, such textiles can be used in the sports field for making sports tights, socks, swimwear, and other clothing, as well as shoes. The elasticity of such textiles is generally obtained by using elastane yarn, which can be included in the textile in the range of 2% to 50% of the total composition of the yarns and / or fibers in the textile. Elastane is a segmented polyurethane that takes the form of a copolymer of soft segments and hard segments. Elastane yarn has a high elongation, that is, an elongation rate. This yarn can be stretched, for example, by more than 600% of its original length before breaking. Elastane also has a high recovery ability, that is, springback. That is, even after being stretched many times, when the stretching stress is relaxed, this yarn will recover its length and reach a length very close to the original length, for example, in the range of 90% to 100% of the original length.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Nevertheless, there are several drawbacks in the production and use of elastane yarn.

[0004] According to the French Environment and Energy Management Agency (ADEME: Agence de l'environnement et de la maitrise de l'energie), the production of 1 kg of elastane yarn generates 1 kg of CO2 equivalent (ADEME Base Impact V2.01). As a result, the production of elastane yarn has a relatively large negative impact on the environment.

[0005] Furthermore, elastane is a thermosetting material and decomposes before melting. Therefore, elastane cannot be recycled thermally. Chemical recycling of elastane has been considered, but using solvents in such processes would, if carried out reasonably, have an excessive impact on the environment.

[0006] As a result, in Europe to date, textiles containing elastane have generally been incinerated or landfilled. Such treatments have an adverse impact on the environment. According to ADEME again, when 1 kg of textile is incinerated, 0.4 kg of CO2 equivalent is emitted, and when 1 kg of textile is landfilled, 2.2 kg of CO2 equivalent is emitted (ADEME Base Impact V2.01).

[0007] Therefore, in view of the current environmental concerns, there is still a need for recyclable elastic textiles. In this regard, there is still a need for recyclable elastic threads that have the same and better elastic properties as existing non-recyclable elastic threads, such as elastane threads. These recyclable elastic threads need to be combinable with recyclable non-elastic threads in order to produce completely recyclable textiles regardless of the proportion of elastic threads in the textiles.

[0008] The object of the present invention is to meet this need by providing a method for producing recyclable elastic threads by a melt extrusion process.

Means for Solving the Problems

[0009] The present invention relates to a method for producing elastic threads by melt spinning. The production method uses a melt spinning machine including an extruder, a spinning metering pump, a spinning pack having at least one die, a cooling system, at least one supply roll, and at least one drawing roll, and includes at least the following steps.

[0010] (A) Granules of a copolymer having a polyamide block and a polyether block are supplied to the extruder. In order to obtain a molten elastomer of a copolymer having a polyamide block and a polyether block by extrusion, the polyamide block is selected from PA11, PA12, PA1010, PA1014, these copolymers and mixtures. The polyether block is derived from polytetramethylene glycol. The hardness of the copolymer according to standard 7691-1 is between 22 and 61 ShD.

[0011] (B) The molten elastomer obtained in step (A) is spun by the die of the spinning pack in order to obtain copolymer yarns having a polyether block and a polyether block.

[0012] (C) The copolymer yarns having a polyamide block and a polyether block obtained in step (B) are cooled at the exit of the die to a temperature strictly lower than the glass transition temperature of the polyamide block, for example in the range of 10°C to 49°C, preferably 10°C to 30°C, more preferably 20°C to 25°C.

[0013] (D) The copolymer yarns having a polyamide block and a polyether block are pre-stretched at the temperature of step (C).

[0014] (E) The copolymer yarns having a polyamide block and a polyether block obtained after completing step (D) are heat-stretched at a temperature strictly higher than the glass transition temperature of the polyamide block, for example from 45°C to about 125°C, preferably 45°C to 120°C, preferably 50°C to 125°C, more preferably 90°C to 120°C.

[0015] (F) The copolymer yarns having a polyamide block and a polyether block obtained after completing step (E) are cold-stretched at a temperature in the range of 10°C to 49°C, preferably 10°C to 30°C, more preferably 20°C to 25°C.

[0016] In the present application, a thread should be understood as any fiber without limitation of length. In particular, the thread may be in the form of a monofilament or a multifilament.

[0017] In the present application, the glass transition temperature should be understood as the temperature at which the polymer is in a glassy state (solid) below that temperature and in a rubbery state (behaves as a plastic solid) above that temperature.

[0018] By the method of the present invention, an elastic thread based on a recyclable copolymer can be obtained, and the elastic thread has excellent elastic properties. In particular, the elastic thread obtained by the method of the present invention has an elongation or elongation at break of, for example, 106% or more, for example, 131% or more, for example, 164.5% or more, for example, 180% or more, for example, 200% or more, for example, about 233% or more in the measurement by the method described in Example 1 of this document. Similarly, the elastic thread obtained by the method of the present invention has a springback of up to 96.6% in the measurement by the method described in Example 1 of this document. Furthermore, the elastic thread obtained by the method of the present invention has a particularly low permanent deformation of, for example, about 2.5% in the measurement by the method described in Example 1 of this document.

[0019] Another aspect of the present invention relates to an elastic thread obtained by the method of the present invention, and the elastic thread has an average elongation at break of 106% or more, preferably 131% or more, preferably 164.5% or more, preferably 180% or more, preferably about 233.3% as measured by the DIN ISO 13895 standard, and / or a springback of 86.5% or more, preferably 91.8% or more, preferably 94% or more, preferably 91.8% or more, preferably 94% or more, preferably 96.3% or more, preferably about 96.6% as measured by the DIN 53835-2 standard.

[0020] Therefore, one aspect of the present invention relates to an elastic thread obtained by the method of the present invention, having an average elongation at break of about 106% as measured by the DIN ISO 13895 standard and a springback of about 86.5% as measured by the DIN 53835-2 standard.

[0021] One aspect of the present invention relates to an elastic yarn obtained by the method of the present invention, having an average breaking elongation of about 131% as measured according to DIN ISO 13895 and a springback of about 94% as measured according to DIN 53835-2.

[0022] One aspect of the present invention relates to an elastic yarn obtained by the method of the present invention, having an average breaking elongation of about 164.5% as measured according to DIN ISO 13895 and a springback of about 91.8% as measured according to DIN 53835-2.

[0023] One aspect of the present invention relates to an elastic yarn obtained by the method of the present invention, having an average breaking elongation of about 180% as measured according to DIN ISO 13895 and a springback of about 96.3% as measured according to DIN 53835-2.

[0024] One aspect of the present invention relates to an elastic yarn obtained by the method of the present invention, having an average breaking elongation of about 233.3% as measured according to DIN ISO 13895 and a springback of about 96.6% as measured according to DIN 53835-2.

[0025] Another aspect of the present invention relates to a textile comprising at least one elastic yarn obtained by the method of the present invention.

[0026] Another aspect of the present invention relates to a method for recycling a textile comprising at least one elastic yarn of the present invention and at least one thermoplastic yarn, preferably polyamide, characterized by comprising the following steps: (i) Shredding the textile to obtain small pieces. (ii) Melting the small pieces obtained in step (i) in an extruder to obtain pellets of the mixture.

[0027] The recycling method may further comprise the following step (iii). (iii) Spinning recycled yarn by melt-extruding the small particles obtained in step (ii).

[0028] The small particles obtained in step (ii) serve as raw materials for all applications, especially for textile applications.

[0029] In the present application, "textile" should be understood as any material made from fibers or yarns. In particular, the textile may be an arrangement of fibers and / or yarns in the form of knitted fabric, woven fabric, non-woven fabric, braided cord, and combinations thereof.

[0030] Another aspect of the present invention relates to clothing containing at least one elastic yarn obtained by the method of the present invention.

[0031] Another aspect of the present invention is a facility for implementing the method of the present invention, comprising: · A spinning device comprising an extruder, a spinning metering pump, and a spinning pack including at least one die. · A cooling system provided at the outlet of the die. · At least one supply roll provided at the outlet of the cooling system. · At least one first stretching roll provided downstream of the supply roll. · At least one second stretching roll provided downstream of the first stretching roll. · Heating means provided between the supply roll and the first stretching roll.

[0032] In the present application, "upstream side" should be understood as the direction towards the "origin", that is, the extrusion position of the yarn (spinning pack), and "downstream side" should be understood as the opposite side, that is, the direction towards the storage position after the yarn has undergone all desired spinning processes.

[0033] In one embodiment, the facility may include a winding roll provided downstream of the supply roll for storing the yarn obtained by the preliminary cold stretching step. Thereafter, the yarn taken from the winding roll is passed over the first stretching roll in a second step.

[0034] The method for producing the elastic yarn of the present invention is based on a melt spinning technique using extrusion of a molten polymer in an extruder and subsequent spin pack. From this point, the different steps described below are carried out continuously.

[0035] In the first step of the method of the present invention, pellets of a copolymer having a polyamide block and a polyether block are supplied to the extruder in order to obtain a molten polymer of the copolymer having a polyamide block and a polyether block by extrusion. The polyamide block is selected from PA11, PA12, PA1010, PA1014, their copolymers and mixtures. The polyether block is derived from polytetramethylene glycol. The hardness of the copolymer according to standard 7691-1 is between 22 and 61 ShD.

[0036] The nomenclature used to define polyamides is described in ISO 1874-1:2011 standard "Plastics - Polyamide (PA) molding and extrusion materials - Part 1: Designation", particularly on page 3 (Tables 1 and 2), and is known to those skilled in the art.

[0037] Furthermore, the expressions "between... and..." and "from... to..." in this description both include the recited end values.

[0038] After "polyamide", it means both homopolyamides and copolyamides.

[0039] The copolymer used in the method of the present invention has a copolymer hardness according to standard 7691-1 between 22 and 61 ShD, preferably between 22 and 55 ShD, preferably between 22 and 40 ShD.

[0040] The polyamide block may be selected from PA 11, PA 12, their copolymers and mixtures. Preferably, the polyamide block is a PA 11 block.

[0041] The copolymer that can be used in the method of the present invention may be a product sold by Arkema under the trade name of "PEBAX® RNEW 35R53 SP 01". The elastomeric copolymer has the following properties. · A density of 1,020 kg / m as measured according to ISO 1183 standard 3 · A Shore D hardness of 25 (15 seconds) as measured according to ISO 7619-1 standard · A melting point of 135 °C as measured according to ISO 11357-1 / -3 standards · A composition of 29% of polyamide PA11, a bio-derived polyamide, as measured according to ASTM D6866 standard.

[0042] Another copolymer that can be used in the method of the present invention is a product sold by Arkema under the trade name of "PEBAX® 7033 SP 01". The elastomeric copolymer has the following properties. · A density of 1,010 kg / m as measured according to ISO 1183 standard 3 · A Shore D hardness of 61 (15 seconds) as measured according to ISO 7619-1 standard · A melting point of 172 °C as measured according to ISO 11357-1 / -3 standards Another copolymer that can be used in the method of the present invention is a product sold by Arkema under the trade name of "PEBAX® 2533 SA 01". The elastomeric copolymer has the following properties. · A density of 1,000 kg / m as measured according to ISO 1183 standard 3 · A Shore D hardness of 22 (15 seconds) as measured according to ISO 7619-1 standard · In the measurement according to ISO 11357-1 standard, the melting point is 134 °C In order to proceed with the first step of the method of the present invention, the copolymer may be pre-dried so that the moisture content becomes 200 ppm or less. For example, the test for measuring the moisture content may be performed using the Karl Fischer titration method.

[0043] The spinning device includes an extruder, such as a screw extruder, a spinning metering pump, and a spinning pack. Generally, the spinning pack includes a die. Conventionally, the spinning pack can include a distribution plate, a metal filter, and filter sand. The extruder and the spinning pump are cleaned before the supply of the copolymer. The spinning device may further include a cooling system, at least one supply roll, such as a pair of supply rolls, and at least one stretching roll, such as a pair of stretching rolls. The stretching roll may or may not be heatable. Preferably, the spinning device further includes a winding roll for accumulating the product yarn.

[0044] In the first step, according to step (A) of the method of the present invention, small particles of the copolymer having the polyamide block and the polyether block described above are supplied to the extruder and melted therein. At the outlet of the extruder, a molten elastomer of the copolymer having the polyamide block and the polyether block is obtained. In the second step, according to step (B) of the method of the present invention, the molten elastomer obtained in step (A) is spun at the die of the spinning pack, and a yarn of the copolymer having the polyamide block and the polyether block is obtained. The spinning metering pump controls the flow of the elastomer toward the die of the spinning pack. The metal filter and the filter sand may be used to remove impurities. The elastomer is injected into the die. At the outlet of the die, a yarn of the copolymer having the polyamide block and the polyether block is formed.

[0045] According to the third step, step (C) of the present invention, the yarn of the copolymer having a polyamide block and a polyether block is cooled at the outlet of the die to a temperature strictly lower than the glass transition temperature of the polyamide block, for example, in the range of 10°C to 30°C, more preferably 20°C to 25°C.

[0046] The cooling of the yarn can be carried out by air cooling or water cooling, depending on the thickness of the yarn and the efficiency of the cooling system. In the case of water cooling, for example, the yarn may be passed through a water tank filled with water in the range of about 20 to 25°C.

[0047] In the case of air cooling, for example, the yarn may be passed through an air flow in the range of about 10 to 25°C.

[0048] In the cooling step, the yarn solidifies.

[0049] According to the fourth step, step (D) of the present invention, the yarn is subjected to a first stretching, or pre-stretching, at the temperature of step (C). Such low-temperature pre-stretching can impart a first elasticity to the yarn.

[0050] In one embodiment, the yarn exiting the die of the spinning pack in step (B) is stretched by passing over a supply roll having a linear velocity V1 in step (D) according to the linear velocity VP of the spinning metering pump. V1 is selected such that the pre-stretching ratio D1 is 2.53 or more. Here, D1 = V1 / VP. Such a pre-stretching ratio can impart a large elasticity to the yarn while maintaining excellent toughness, and thus good standard characteristics can be achieved.

[0051] In the present invention, the "linear velocity" of the pump or the delivery, stretching or winding roll should be understood to mean the linear velocity of the outer wall of the pump or roll that contacts the yarn during the movement of the yarn.

[0052] In one embodiment, the yarn obtained after completing step (D) may be stored on a winding roll before being used in step (E).

[0053] Step 5, according to step (E) of the present invention, the yarn of the copolymer having a polyamide block and a polyether block obtained by completing step (D) is heat-drawn whether it is stored on a winding roll or directly from a supply roll. The temperature of the heat drawing is strictly higher than the glass transition temperature of the polyamide block of the copolymer, in the range of about 40 to 125 ° C, preferably in the range of 50 to 125 ° C, preferably in the range of 90 to 125 ° C. The temperature of the heat drawing depends on the linear velocity of the yarn. For example, this temperature may be 115 ° C. For this purpose, the yarn passes through or contacts heating means brought to the desired temperature. For example, the heating means may be an oven brought to the desired temperature. Instead of or in combination with this, the heating means may be one or more drawing rolls brought to the desired temperature. For example, the temperature of the heat drawing is 115 ° C, and the heating means may be an oven located between two pairs of cold drawing rolls. As another example, the temperature of the heat drawing is 45 ° C, and the heating means may be a drawing roll at a high temperature (for example, 45 ° C). By heat drawing, the thickness of the yarn can be reduced, in other words, the fineness can be increased.

[0054] In one embodiment, in step (E), the yarn is drawn by passing over a first drawing roll having a drawing linear velocity V2. V2 is selected such that the draw ratio D2 is 8 or less. Here, D2 = V2 / V1. When the heating means is an oven and the yarn is passed through it, the oven may be located between the supply roll and the first drawing roll. Instead of this, the first drawing roll may be heatable to the desired temperature. With such a high-temperature draw ratio, the yarn can be significantly thinned while maintaining interesting elasticity.

[0055] Step 6, according to step (F) of the present invention, the yarn of the copolymer having a polyamide block and a polyether block obtained by completing step (E) is cold drawn. The temperature of this cold drawing may be in the range of 20 to 49°C, preferably in the range of 20 to 25°C. This second cold drawing imparts additional elasticity to the yarn.

[0056] In one embodiment, in step (F), it is drawn by passing over a second drawing roll having a draw line speed V3. V3 is selected such that the cold draw ratio D3 is 1 or more. Here, D3 = V3 / V2. Such a draw ratio in this step makes the resulting yarn have very excellent elasticity.

[0057] In one embodiment, D1 = 5.07. In one embodiment, D1 = 5.07 and D2 = 4. In one embodiment, D1 = 5.07, D2 = 4 and D3 = 1. The resulting yarn has very excellent elasticity and also excellent fineness.

[0058] In one embodiment, the second drawing roll is a winding roll. That is, the yarn is wound around this roll for storage.

[0059] In one embodiment, the stored yarn is subsequently newly drawn. This is called post-drawing and is performed to improve springback.

[0060] This method may further comprise the following step (G).

[0061] (G) The yarn of the copolymer having a polyamide block and a polyether block obtained by completing step (F) is post-drawn. The temperature of the post-drawing is a temperature strictly lower than the glass transition temperature of the polyamide block, for example, in the range of 10 to 30°C, preferably in the range of 20 to 25°C.

[0062] During step (G), the yarn may be post-drawn by passing over a first post-drawing roll having a linear velocity V4 and then over a second post-drawing roll having a linear velocity V5. V4 and V5 are selected such that the post-drawing ratio D4 is 1.65 or more. Here, D4 = V5 / V4.

[0063] This method may further comprise the following step (H).

[0064] (H) The yarn having the polyamide block and the polyether block obtained by completing step (G) is stress-relieved. The temperature for stress-relief is a temperature strictly lower than the glass transition temperature of the polyamide block, for example, in the range of 10 to 30 °C, preferably in the range of 20 to 25 °C.

[0065] During step (H), the yarn may be stress-relieved by passing over a winding roll having a linear velocity V6. The velocity V6 is selected such that V6 / V4 is in the range of 1 to 1.50, preferably in the range of 1 to 1.25, more preferably in the range of 1.00 to 1.05.

[0066] The equipment of the present invention may further comprise the following: · At least one first post-drawing roll provided on the downstream side of the winding roll · At least one second post-drawing roll provided on the downstream side of the first post-drawing roll.

[0067] In one embodiment, at the completion of step (F) or subsequent post-drawing, particularly step (G) or subsequent stress-relief, particularly step (H), the yarn is heat-set. By heat-setting, the yarn can maintain its elastic and mechanical properties over a long period, for example, for one year. For example, the heat-setting may be performed at a temperature strictly higher than the glass transition temperature of the polyamide block, for example, in the range of about 70 °C to 90 °C, preferably about 80 °C.

[0068] Other features and advantages of the present invention will become more apparent from the following examples and the accompanying drawings.

Brief Description of the Drawings

[0069]

Figure 1

Figure 2

Figure 3

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Figure 9

Embodiments for Carrying Out the Invention

[0070] FIG. 1 shows a first embodiment of equipment 100 capable of implementing the method of the present invention. The equipment 100 includes a spinning device 1 including an extruder 2 and a spinning pack 3. The equipment 100 includes a water tank 4 filled with water 5, a pair 6 of supply rolls 6a, a pair 7 of drawing rolls 7a, and a winding roll 8. Finally, the equipment 100 includes an oven 9 located between the supply roll 6a and the drawing roll 7a.

[0071] Hereinafter, with reference to FIG. 1, the steps in the method of the present invention will be described.

[0072] The small pellets 10 of the copolymer having a polyamide block and a polyether block are commercially available from Arkema under the trade name "PEBAX RNEW 35R53 SP 01". The polyamide block of this copolymer is a PA11 block, and the polyether block is derived from polytetramethylene glycol.

[0073] This elastomeric copolymer has the following properties. · In the measurement according to the ISO 1183 standard, a density of 1.020 kg / m 3 of · In the measurement according to the ISO 7619-1 standard, a Shore D hardness of 25 (at 15 seconds) · In the measurement according to the ISO 11357-1 / -3 standards, a melting point of 135 °C · In the measurement according to the ASTM D6866 standard, a composition of 29% of the polyamide PA11 which is a bio-derived polyamide Before being introduced into the extruder, the pellets 10 are preferably dried to a moisture content of 200 ppm or less. For example, the test for measuring the moisture content may be performed using the Karl Fischer titration method. For example, the pellets 10 may be dried overnight under vacuum in an oven at 80 °C.

[0074] Thereafter, the pellets 10 are introduced into the extruder 2 at the height of the inlet 2a of the extruder 2 by the supply hopper 11. The extruder 2 includes a main body 12 consisting of a cylinder in which a worm gear (not shown) rotates inside. The extruder 2 includes a heating region 14 in the main body 12, and the temperature of the heating region 14 increases from the inlet 2a of the extruder 2 toward the outlet 2b of the extruder 2. For example, the temperature of the heating region 14 may vary from 195 °C near the inlet 2a to 205 °C near the outlet 2b. The pellets 10 are mixed and melted in the extruder 2. At the outlet 2b of the extruder 2, a molten elastomer is obtained, which is transported to the spinning pack 3 by a transport line consisting of a heat-insulating metal hose 16. The temperature in the transport line is close to the outlet temperature of the extruder 2, and thus, for example, is 205 °C.

[0075] The spinning pack 3 includes a metering pump 17, a filter 18, and a die 19. The metering pump 17 controls the flow of the molten elastomer toward the die 19. In the illustrated example, the metering pump 17 rotates at a linear velocity of 7.5 m / min. The filter 18 is provided between the metering pump 17 and the die 19 to remove impurities that may be present in the molten elastomer. In the illustrated example, the filter 18 has a pressure of 40 atmospheres.

[0076] After passing through the filter 18, the molten elastomer is injected into the die 19 at approximately 210°C, which is the temperature of the spinning pack 3. In the illustrated example, the size of the holes in the die 19 is 0.73 mm, and the ratio of the length (L) to the diameter (D) of the die holes (L / D ratio) is 1 / 4. In this way, the yarn 20 is formed at the outlet of the die 19. The yarn 20 exits the die 19 at a linear velocity VP corresponding to the linear velocity of the metering pump 17. In the illustrated example, the die 19 has only one hole, and the yarn 20 takes the form of a staple fiber yarn.

[0077] As shown in FIG. 1, after exiting the die 19, the yarn 20 passes through a water tank 4 filled with water 5. The water is at room temperature, that is, 20°C to 25°C. In this way, the yarn 20 is cooled by water cooling.

[0078] By cooling the yarn 20, it can be solidified.

[0079] After being cooled, the yarn 20 passes over a supply roll 6a. The linear velocity V1 of the supply roll 6a is faster than the linear velocity V. Therefore, the yarn 20 undergoes pre-drawing between the outlet of the die 19 and the supply roll 6a, and the speed ratio is equal to D1 = V1 / V. This pre-drawing is performed at a low temperature, particularly at a temperature lower than the glass transition temperature of the polyamide block of the copolymer, for example, at room temperature of 20°C to 25°C. By such low-temperature pre-drawing, the first elasticity can be imparted to the yarn 20.

[0080] After that, the yarn 20 passes through the oven 9 and is further sent to the stretching roll 7a at the outlet of the oven. In the illustrated example, the temperature applied to the yarn 20 in the oven 9 is about 115°C. In other examples not shown, the temperature of the oven may be in the range of 50°C to 120°C.

[0081] The stretching roll 7a has a linear velocity V2, which is faster than the velocity V1. Therefore, the yarn 20 is thermally stretched between the supply roll 6a and the stretching roll 7a. The speed ratio is D2 = V2 / V1. By this thermal stretching, the thickness of the yarn 20 decreases and gives some fineness.

[0082] After that, the yarn 20 is sent to the winding roll 8. In the illustrated example, the linear velocity V3 of the winding roll is 150 m / min. This linear velocity is faster than the linear velocity V2. Therefore, the yarn 20 is stretched between the stretching roll 7a and the winding roll 8. The speed ratio is D3 = V3 / V2. This stretching is performed outside the oven 9 at room temperature, that is, in the range of 20°C to 25°C. By this second cold stretching, additional elasticity is imparted to the yarn 20.

[0083] In an example not shown, the winding roll 8 also functions as a stretching roll, and the path of the yarn continues toward the subsequent winding roll.

[0084] FIG. 5 shows a second embodiment of the facility 200 capable of implementing the method of the present invention. In FIG. 5, the reference numerals indicating the components equivalent to those in FIG. 1 are the same.

[0085] The facility 200 includes a spinning device 1 including an extruder 2 and a spinning pack 3. The facility 200 further includes one pair of supply rolls 6a, two pairs of heatable stretching rolls 26a, one pair of relaxation rolls 27a, and a winding roll 8.

[0086] The extruder 2 includes an inlet 2a, an outlet 2b, and a supply hopper 11. The extruder 2 includes a heating region 14, and the temperature in the heating region 14 increases from the inlet 2a of the extruder 2 toward the outlet 2b of the extruder 2.

[0087] The copolymer having a polyamide block and a polyether block is the same as that described with respect to FIG. 1, that is, it is sold by Arkema under the trade name "PEBAX RNEW 35R53 SP 01".

[0088] As shown in FIG. 5, the small particles 10 of the copolymer are adjusted in the same manner as described with respect to FIG. 1 and introduced into the extruder 2 through the supply hopper 11.

[0089] At the outlet of the extruder 2, the molten elastomer is transported to the spinning pack 3 through the transport line 16.

[0090] The spinning pack 3 includes a metering pump 17, a filter 18, and a die 19. In the facility 200, the metering pump 17 rotates at a linear velocity of 65.4 m / min. The die 19 has 17 holes, each hole having a size of 0.6 mm, and the ratio of the length (L) of the holes of the die 19 to the diameter (D) (L / D ratio) is 1 / 4. Therefore, the yarn 21 coming out of the die 19 is a multifilament yarn. The yarn 21 is discharged from the die 19 at a linear velocity VP corresponding to the linear velocity of the metering pump 17.

[0091] The yarn 21 is cooled by an air-cooling means in the form of an air flow 22, and the air flow 22 has a temperature of 25°C or lower, for example, 10°C. Preferably, as shown by the arrow F in FIG. 5, the air flow 22 is applied to the yarn 21 over a height of several meters of the yarn 21, for example, 5 m.

[0092] The facility 200 includes a device 23 for applying a lubricating oil to the yarn 21. The facility 200 also includes a guide 24 for combining the various filaments of the yarn 21 obtained from the holes of the die 19. By applying a lubricating oil to the yarn 21 and using the guide 24, all the filaments obtained from the holes of the die 19 can be combined together to obtain a multifilament yarn 21.

[0093] Thereafter, the yarn 21 is conveyed onto the supply roll 6a and maintained at room temperature, that is, a temperature in the range of 20 to 25°C. The supply roll 6a has a linear velocity V1, which is faster than the linear velocity VP. Therefore, the yarn 21 undergoes pre-stretching between the die 19 and the supply roll 6a. The speed ratio is equal to D1 = V1 / VP. This pre-stretching is carried out at a low temperature, specifically, at a temperature strictly lower than the glass transition temperature of the polyamide block of the copolymer. For example, it is a temperature in the range of 20 to 25°C. By such low-temperature pre-stretching, the first elasticity is imparted to the yarn 21.

[0094] Thereafter, the yarn 21 is conveyed onto the first pair 25 of the rolls 25a maintained at room temperature, that is, a temperature range of 20 to 25°C. The linear velocity of the roll 25a is the same as the linear velocity of the supply roll 6a.

[0095] Thereafter, the yarn 21 is conveyed onto the two pairs 26 of the heatable stretching rolls 26a. The roll 26a has a temperature of 50°C and a linear velocity V2 equal to V1. Therefore, the yarn 21 is heat-stretched between the supply roll 6a and the stretching roll 26a. The ratio of the speeds is equal to D2 = V2 / V1. By this heat-stretching, the thickness of the yarn 21 decreases and some fineness is obtained.

[0096] Thereafter, the yarn 21 is conveyed onto the second pair 28 of the rolls 28a maintained at room temperature, that is, a temperature range of 20 to 25°C. The linear velocity V3 of the roll 28a is faster than the linear velocity V2. Therefore, the yarn 21 is stretched between the stretching roll 26a and the roll 28a. The ratio of the speeds is equal to D3 = V3 / V2. This stretching is carried out at room temperature, that is, a temperature range of 20 to 25°C. By this second cold stretching, additional elasticity is imparted to the yarn 21.

[0097] Thereafter, the yarn 21 is conveyed onto the relaxation roll 27a. The roll 27a is maintained at room temperature, that is, a temperature range of 20 to 25°C, and its linear velocity is equal to the linear velocity of the roll 28a.

[0098] Thereafter, the yarn 21 is conveyed to the take-up roll 8. The take-up roll 8 is maintained at room temperature, that is to say, in the temperature range of 20 to 25°C. Its linear velocity may be slightly slower than V3.

[0099] Figure 8 shows an equipment unit 300 capable of performing a post-drawing step and a stress relaxation step. These steps are carried out following the extrusion, pre-drawing, hot drawing, and cold drawing steps described for the yarns (20, 21) in FIGS. 1 and 5. The yarn 22 on which the post-drawing and stress relaxation steps described in FIG. 8 are carried out may be a monofilament yarn like the yarn 20 obtained by the method described in FIG. 1, or may be a multifilament yarn like the yarn 21 obtained by the method described in FIG. 5. The yarn 22 is wound around the take-up roll 8 for storage.

[0100] The installation unit 300 includes a first post-drawing roll 30a, a pair 31 of a second post-drawing roll 31a, and a final take-up roll 32. The installation unit 300 has a polyamide block and a polyether and is maintained at a temperature strictly lower than the glass transition temperature in the polyamide block of the copolymer constituting the yarn 22, for example, in the range of 10 to 30°C, preferably in the range of 20 to 25°C.

[0101] After the yarn 22 is conveyed onto the first post-drawing roll 30a, it is then conveyed to the second post-drawing roll 31a. The linear velocity of the first post-drawing roll 30a is V4, and the linear velocity of the second post-drawing roll 31a is V5. The linear velocity V5 is faster than the linear velocity V4. Therefore, the yarn 22 is post-drawn, and the speed ratio is equal to D4 = V5 / V4. By such post-drawing, additional elasticity is imparted to the yarn 22.

[0102] Thereafter, the yarn 22 is conveyed to the final winding roll 32. The linear velocity of the final winding roll 32 is V6. Preferably, this linear velocity V6 is slightly faster than the linear velocity V4. For example, the ratio V6 / V4 is in the range of 1 to 1.50, preferably in the range of 1 to 1.25, and more preferably in the range of 1.00 to 1.05. Thereby, a stress relaxation step is performed on the yarn 22. This step does not change the additional elasticity imparted by passing over the post-drawing rolls (30a, 31a). The elastic yarns (20, 21, 22) obtained by the method of the present invention described above, particularly in FIGS. 1, 5 and 8, can be incorporated into clothing such as sports tights, swimsuits, and textiles. The yarns obtained by the method of the present invention are completely recyclable. Therefore, textiles and clothing containing these yarns are also completely recyclable. For example, the yarns obtained by the method of the present invention, the textiles or clothing containing the same can be shredded into small pieces. These small pieces can be melted to obtain new pellets of a copolymer having a polyamide block or a polyether block. These pellets can be introduced again into the extruder of the spinning apparatus to form new yarns. Therefore, it is possible to avoid landfill and / or incineration of the elastic yarns.

Examples

[0103] (Example 1) According to the method of the present invention described above with reference to FIG. 1, the parameters were varied to obtain several yarns 20.

[0104] (a) Tests Conducted The method described with reference to FIG. 1 was carried out, and several tests were performed while varying the following parameters. · The linear velocity V1 of the supply roll 6a, · The linear velocity V2 of the drawing roll 7a, · The draw ratio D1, · The draw ratio D2, · The draw ratio D3.

[0105] The fixed parameters are as follows. · The linear velocity VP is 7.4 m / min, · The linear velocity V3 is 150 m / min, · The total draw ratio, i.e., TD = D1×D2×D3, is 20.3.

[0106] That is, the tests listed in Table 1 below were conducted.

[0107]

Table 1

[0108] Table 1: Variation of parameters V1, V2, V3, D2, and D3 (b) Evaluation of mechanical properties For each of the tests 1 - 4, after winding the obtained yarn onto the take-up roll 8, the following mechanical properties were measured. · Average fineness of the yarn: The fineness is expressed in denier. This represents the size (diameter) of the yarn. The fineness was measured by the method described in the DIN EN ISO 13392 standard. · Average tenacity of the yarn: The tenacity is expressed in cN / tex. This represents the tensile strength of the yarn. The tenacity was measured by the method described in the DIN EN ISO 13895 standard. · Average breaking elongation: The average breaking elongation is expressed as a percentage (%). This represents the elasticity of the yarn. The higher the average breaking elongation of the yarn, the greater the elasticity of the yarn. The average breaking elongation was measured by the method described in the DIN ISO 13895 standard.

[0109] All tests were carried out under ambient conditions (relative humidity (RH) 65% ± 2%, temperature 20°C ± 2°C) standardized according to the DIN EN ISO 139 standard.

[0110] A, B, C, and D in Figure 3 are graphs representing the tensile strength as a function of elongation for the yarns of tests 1, 2, 3, and 4, respectively.

[0111] The results are shown in Table 2 below.

[0112]

Table 2

[0113] Table 2: Mechanical properties From these results, it is shown that by the method of the present invention, it is possible to produce a yarn having an average breaking elongation of 200% or more, particularly 233.3%, based on a recyclable copolymer having a polyamide block and a polyether. That is, the yarn of Test 1 can be stretched without breaking up to 233.3% of the initial length. The yarn has very excellent elasticity and can be used for elastic textiles such as sports tights and swimsuits.

[0114] Furthermore, since it is chemically polyamide and polyether-based, such elastic yarns can be used to make elastic textiles together with other non-elastic yarns of polyamide (e.g., polyamide PA 6 or PA66) or polyester-based. Such elastic textiles are completely recyclable. Therefore, the resulting elastic textiles do not need to be landfilled or incinerated.

[0115] The results in Table 2 above also show that, if the fineness is the same, the greater the preliminary cold drawing ratio (D1), the greater the elasticity of the yarn. That is, Test 1 has a preliminary cold drawing ratio D1 of 5.07 and a particularly high (233.3%) average breaking elongation. On the other hand, Test 3 has a preliminary cold drawing ratio of 2.53 and a low average breaking elongation (106%).

[0116] Therefore, the preliminary cold drawing ratio D1 is preferably 2.53 or more.

[0117] The results in Table 2 above also show that, if the fineness is the same and the preliminary cold drawing ratio is the same, the greater the cold drawing ratio D3 after passing through the oven, the greater the elasticity of the yarn. That is, Test 4 has a cold drawing ratio (D3) of 1.51 after passing through the oven and a particularly high (180%) average breaking elongation. On the other hand, Test 3 has a cold drawing ratio (D3) of 1 after passing through the oven and a low (106%) average breaking elongation.

[0118] Thus, the cold drawing ratio (D3) after passing through the oven is preferably 8 or more.

[0119] In any case, it has been shown that the lower the hot drawing ratio (D2), the greater the elasticity of the yarn. Therefore, the hot drawing ratio (D2) is preferably 8 or less.

[0120] (c) Evaluation of viscoelastic properties For each of Tests 1-4, after winding the obtained yarn around the winding roll 8, the following viscoelastic properties were measured. · Springback: Springback is expressed as a percentage (%). This represents the recovery force of the elastic yarn when the stress applied to deform the elastic yarn is released. The goal is to obtain the largest possible springback. Springback was measured by the method described in DIN 53835-2 standard. · Permanent deformation: Permanent deformation or irreversible deformation is expressed as a percentage (%). This represents the elasticity permanently lost after stretching several times in succession. The aim is to obtain the smallest possible permanent deformation. Permanent deformation was measured by the method described in DIN 53835-2 standard.

[0121] All tests were carried out under ambient conditions (relative humidity (RH) 65% ± 2%, temperature 20°C ± 2°C) standardized according to DIN EN ISO 139 standard.

[0122] A, B, C, and D in FIG. 4 are diagrams showing the hysteresis curves obtained for the yarns of Tests 1, 2, 3, and 4, respectively. Based on these curves, the springback and permanent deformation of the yarns of Tests 1-4 can be calculated.

[0123] The results are shown in the graph of FIG. 2.

[0124] As shown in this graph, by the method of the present invention, a thread such as a monofilament thread can be produced from a recyclable copolymer having excellent viscoelastic properties and having a polyamide block and a polyether block. The springback of Test 1 is 96.6%, and the permanent deformation is only 2.5%. Therefore, by the method of the present invention, an elastic thread having elastic properties equivalent to those of a conventional non-recyclable elastic thread and being recyclable can be produced.

[0125] (Example 2) According to the method of the present invention described above with reference to FIG. 5, a thread 21 was obtained.

[0126] The values of the parameters are as follows. · The linear velocity VP is 65.4 m / min, · The linear velocity V1 of the supply roll 6a is 1,333 m / min, · The linear velocity V2 of the stretching roll 26a heated to 50°C is 1,333 m / min, · The linear velocity V3 of the roll 28a at room temperature is 2,000 m / min, · The linear velocity of the take-up roll is 1,950 m / min, · Regarding the draw ratio D1: D1 = V1 / VP = 20.4, · Regarding the draw ratio D2: D2 = V2 / V1 = 1, · Regarding the draw ratio D3: D3 = V3 / V2 = 1.5.

[0127] The thread 21 is composed of 34 filaments and has a linear density of 193 dtex (174 D).

[0128] The mechanical properties of the thread 21 were measured by the method described in Example 1.

[0129] FIG. 6 is a graph showing the tensile strength of the thread 21 as a function of elongation.

[0130] The results are shown in Table 3 below.

[0131]

Table 3

[0132] Table 3: Mechanical properties The viscoelastic properties of the yarn 21 were measured by the method described in the example.

[0133] FIG. 7 is a graph showing the hysteresis curve obtained for the yarn 21.

[0134] The results are shown in Table 4 below.

[0135] [Table 4]

[0136] Table 4: Viscoelastic properties As shown in this example, by the method of the present invention, a yarn such as a multifilament yarn can be produced from a recyclable copolymer having excellent viscoelastic properties and having a polyamide block and a polyether block. Therefore, by the method of the present invention, an elastic yarn having elastic properties equivalent to those of a conventional non-recyclable elastic yarn and being recyclable can be produced.

[0137] (Example 3) For the multifilament yarn 21 obtained according to the method described in FIG. 5, a post-drawing step and a stress relaxation step were performed by the method described in FIG. 8. The parameters at that time are as follows. · Linear velocity V4 of the first post-drawing roll 30a: 103 m / min · Linear velocity V5 of the second post-drawing roll 31a: 107 m / min · For the post-drawing ratio D4: D4 = V5 / V4 = 1.65 · Linear velocity of the final winding roll 32: 107 m / min · For the stress relaxation ratio D5: D5 = V6 / V5 = 0.63 Therefore, the total post-drawing ratio over two steps: D4 × D5 = 1.04

[0138] Final average fineness after the post-drawing step and stress relaxation step on the final take-up roll 32: 194 denier.

[0139] A in FIG. 9 is a graph showing the curve of tensile strength as a function of elongation in the multifilament yarn 21 before performing the post-drawing step and stress relaxation step.

[0140] B in FIG. 9 is a graph showing the curve of tensile strength as a function of elongation in the multifilament yarn 21 after performing the post-drawing step and stress relaxation step.

[0141] The standards used for conducting these tests are the same as those in the previous example.

[0142] In these curves, · The portion indicated by A corresponds to the initial elastic portion, · The portion indicated by B corresponds to the rigid body portion, · The portion indicated by C corresponds to the viscoelastic portion.

[0143] The results are shown in Table 5 below.

[0144]

Table 5

[0145] These results indicate that the yarn has better elastic properties after post-drawing and stress relaxation.

[0146] (Example 4) A textile containing the elastic yarns (20, 21, 22) of the present invention obtained by the method described with reference to FIGS. 1, 5 and 8 and polyamide 6 (PA 6) was recycled as described below.

[0147] (1) Preparation of small pieces and mixtures of small pieces The yarns composed of elastic yarn and polyamide 6 are shredded to obtain small pieces.

[0148] The following notations are used: Piece 1: A piece of yarn made of polyamide 6, Piece 2: A piece of elastic yarn.

[0149] The following three mixtures were prepared: Mixture 1: This mixture, in parts by mass relative to the parts by mass of the mixture, · contains 90% of Piece 1, · and 10% of Piece 2.

[0150] Mixture 2: This mixture, in parts by mass relative to the parts by mass of the mixture, · contains 80% of Piece 1, · and 20% of Piece 2.

[0151] Mixture 3: This mixture, in parts by mass relative to the parts by mass of the mixture, · contains 70% of Piece 1, · and 30% of Piece 2.

[0152] These mixtures were extruded using a 6-zone screw extruder. The parameters used for extrusion are shown in Table 6 below.

[0153]

Table 6

[0154] At the exit of the extruder, the molten mixture was pelletized. The following notations are used: Pellet 1: Pellets obtained by extrusion of Mixture 1 Pellet 2: Pellets obtained by extrusion of Mixture 2 Pellet 3: Pellets obtained by extrusion of Mixture 3.

[0155] (2) Evaluation of properties For Piece 1, Piece 2, Pellet 1, Pellet 2, and Pellet 3, the properties were evaluated by the following tests: Differential Scanning Calorimetry (DSC) Thermal Gravimetric Analysis (TGA) Viscosity index measurement

[0156] (a) Differential Scanning Calorimetry (DSC) This test can confirm whether the small particles are single-phase or two-phase. The test was carried out according to the following procedure: First DSC cycle: From -70°C to +350°C or lower if thermal degradation starts before that, without holding time Second DSC cycle: From +350°C to -70°C, without holding time Third DSC cycle: From -70°C to +350°C or lower if thermal degradation starts before that Final cooling

[0157] The measurement was carried out on small pieces 1 and 2 after the first cycle

[0158] The measurement was carried out on small particles 1, 2, and 3 after the second cycle. The glass transition temperature is determined from the second cycle. The melting point is determined from the first cycle. The crystallization temperature is determined from the first cooling cycle

[0159] The results are shown in Table 7 below

[0160] [Table 7]

[0161] From these results, it can be seen that small particles 1, 2, and 3 are homogeneous mixtures

[0162] (b) Thermal Gravimetric Analysis This test can confirm the start of thermal degradation for each small piece / small particle. The test was carried out according to the following procedure: Nitrogen condition Heat to 600°C The heating rate is always 10°C / min

[0163] The results are shown in Table 8 below.

[0164]

Table 8

[0165] From these results, it can be seen that Chip 1, Chip 2, and Granules 1, 2, and 3 of the extruded mixture begin to thermally deteriorate at temperatures higher than their respective spinning temperatures. Specifically: Spinning temperature of Chip 1: 260 °C, Spinning temperature of Chip 2: 220 °C, Spinning temperature of Granules 1, 2, and 3: 250 °C.

[0166] From these results, it can be seen that the spinning conditions of Granules 1, 2, and 3 of the extruded mixture are met.

[0167] (c) Viscosity Index Measurement This test can confirm whether the viscosity of each of the extruded Granules 1, 2, and 3 is suitable for melt spinning. The test was conducted using sulfuric acid H2SO4 (0.5%).

[0168] The results are shown in Table 9 below.

[0169]

Table 9

[0170] From these results, it can be seen that the extruded Granules 1, 2, and 3 have good viscosities suitable for melt spinning. (3) Production of Recycled Yarn from Granule 2 of the Extruded Mixture Granule 2 in the mixing section was dried at 65 °C under vacuum overnight.

[0171] A spinning device equipped with an extruder, a spinning metering pump, and a spinning pack having a die was prepared. The extruder was cleaned and the spinning pack was inserted.

[0172] Small pellets 2 were supplied to the extruder and extrusion was started.

[0173] It was confirmed that stable extrusion and then stable spinning were possible. That is, a recycled multifilament yarn of about 480 dtex could be obtained.

[0174] The recycled multifilament thus obtained can be used in the production of new textiles.

Claims

1. A method for producing elastic yarns (20, 21) by melt spinning using a spinning apparatus (1) comprising an extruder (2), a spinning metering pump (17), a spinning pack (3) having at least one die (19), a cooling system (4, 5, 22), at least one feed roll (6a), and at least one drawing roll (7a, 26a), wherein at least the following steps are required: (A) A step of supplying small particles (10) of a copolymer having polyamide blocks and polyether blocks to an extruder (2) in order to obtain a molten elastomer of a copolymer having polyamide blocks and polyether blocks by extrusion, wherein the polyamide blocks are selected from PA11, PA12, PA1010, PA1014, copolymers and mixtures thereof, the polyether blocks are derived from polytetramethylene glycol, and the hardness of the copolymer according to standard 7691-1 is between 22 and 61 ShD. (B) In order to obtain polyether blocks and copolymer yarns (20, 21) having polyether blocks, the molten elastomer obtained in step (A) is spun by the die (19) of the spinning pack (3), (C) A step of cooling the polyether block and copolymer yarn (20,21) having the polyether block obtained in step (B) at the outlet of the die (19) to a temperature strictly lower than the glass transition temperature of the polyamide block, for example, from 10°C to 49°C. (D) Pre-stretching the polyether block and the copolymer yarn (20,21) having the polyether block at the temperature of step (C), (E) A step of heat stretching the copolymer yarn (20,21) having the polyamide block and polyether block obtained by completing step (D) at a temperature strictly higher than the glass transition temperature of the polyamide block, for example, from 45°C to about 125°C. (F) The copolymer yarn (20,21) having the polyamide block and polyether block obtained by completing step (E) is cold-stretched at a temperature in the range of 10°C to 49°C. Methods that include...

2. In the method of claim 1, A method characterized in that, in step (B), the yarn (20, 21) that exits from the die of the spinning pack in accordance with the linear speed VP of the spinning metering pump is stretched in step (D) by passing over a supply roll (6a) having a linear speed V1, wherein V1 is selected such that, when the pre-stretching ratio D1 = V1 / VP, D1 is 2.53 or greater.

3. In the method of claim 1 or 2, A method characterized in that, in step (E), the yarn (20, 21) is stretched by passing over a first stretching roll (7a, 26a) having a stretching linear speed V2, and V2 is selected such that when the stretching ratio D2 = V2 / V1, D2 is 8 or less.

4. In the method of claim 1, A method characterized in that, in step (F), the yarn (20,21) is stretched by passing over a second stretching roll having a stretching linear speed V3, and V3 is selected such that when the cold stretching ratio D3 = V3 / V2, D3 is 1 or more.

5. In the method of claim 4, A method characterized in that the second stretching roll is a winding roll (8).

6. In the method of claim 1, A method characterized in that, in step (C), the yarn (20) is cooled by water cooling (5).

7. In the method of claim 1, A method characterized in that, in step (C), the yarn (20) is cooled by air cooling.

8. In the method of claim 1, A method characterized in that the copolymer yarn (20) having the polyamide block and the polyether block obtained by completing step (F) is heat-set at a temperature strictly higher than the glass transition temperature of the polyamide block, for example in the range of about 70°C to 90°C, preferably about 80°C.

9. In the method of claim 1, Step (G) below, (G) The copolymer yarn (20,21) having the polyamide block and polyether block obtained by completing step (F) is further stretched at a temperature strictly lower than the glass transition temperature of the polyamide block, for example, in the range of 10 to 30°C, preferably in the range of 20 to 25°C. A method characterized by further comprising the following.

10. In the method of claim 9, A method characterized in that, in step (G), the yarn (20,21) is post-stretched by passing over a first post-stretching roll having a linear speed V4, and then over a second post-stretching roll having a linear speed V5, wherein V4 and V5 are selected such that when the post-stretching ratio D4 = V5 / V4, D4 is 1.65 or more.

11. In the method of claim 9 or 10, Step (H) below, (H) The copolymer yarn (20,21) having the polyamide block and polyether block obtained by completing step (G) is subjected to stress relaxation at a temperature strictly lower than the glass transition temperature of the polyamide block, for example, in the range of 10 to 30°C, preferably in the range of 20 to 25°C. A method characterized by further comprising the following.

12. In the method of claim 11, In step (H), A method characterized in that the yarn (20,21) is stress-relieved by passing over a winding roll having a linear speed V6, wherein V6 is selected such that V6 / V4 is in the range of 1 to 1.50, preferably in the range of 1 to 1.25, and more preferably in the range of 1.00 to 1.

05.

13. In the method of claim 2, A method characterized by D1 = 5.

07.

14. In the method of claim 3, A method characterized by D2 = 4.

15. In the method of claim 13, A method characterized by D2 = 4.

16. In the method of claim 4, A method characterized by D3=1.

17. In the method of claim 14, A method characterized by D3=1.

18. In the method of claim 1, A method characterized in that the hardness of the copolymer, as measured according to standard 7691-1, is between 22 and 55 ShD.

19. In the method of claim 1, The method is characterized in that the polyamide block is selected from PA11, PA12, copolymers thereof, and mixtures thereof.

20. In the method of claim 19, A method characterized in that the polyamide block is a PA11 block.

21. Elastic yarn (20,21) obtained by any one of the methods of claims 1, 2, 4 to 10, 13, 15, 16 and 18 to 20, An elastic yarn having a breaking elongation of 106% or more as measured according to DIN ISO 13895, and / or a springback of 86.5% or more as measured according to DIN 53835-2.

22. A textile comprising at least one yarn (20, 21) obtained by any one of the methods of claims 1, 2, 4-10, 13, 15, 16 and 18-20.

23. A textile comprising at least one of the yarns (20,21) of claim 21.

24. A garment comprising at least one yarn (20, 21) obtained by any one of the methods of claims 1, 2, 4-10, 13, 15, 16 and 18-20.

25. A garment comprising at least one of the yarns (20,21) of claim 21.

26. Equipment (100,200) for carrying out any one of the methods of claims 1, 2, 4 to 10, 13, 15, 16 and 18 to 20, A spinning apparatus (1) comprising an extruder (2), a spinning metering pump (17), and a spinning pack (3) having at least one die (19), A cooling system (4, 5, 22) is located at the outlet of the aforementioned nozzle (19), At least one supply roll (6a) is located at the outlet of the cooling system (4, 5, 22), At least one first stretching roll (7a, 26a) is provided downstream of the supply roll (6a), At least one second stretching roll (8, 28a) is provided downstream of the first stretching roll (7a, 26a), A heating means (9, 26) is provided between the supply roll (6a) and the first stretching rolls (7a, 26a), Equipment that includes the following features.

27. In the apparatus of claim 26, The apparatus is characterized in that the second stretching roll (8) is a winding roll.

28. In the apparatus of claim 27, A first post-stretching roll (30a) is provided downstream of the winding roll (8), A second back-stretching roll (31a) is provided downstream of the first back-stretching roll (30a), Equipment characterized by further comprising the following.

29. A method for recycling textiles comprising at least one elastic yarn (20, 21, 22) obtained by any one of the methods of claims 1, 2, 4-10, 13, 15, 16 and 18-20, and preferably at least one thermoplastic yarn made of polyamide, the method comprising the following steps: (i) The step of shredding the textile to obtain small pieces, (ii) A step in which the small pieces obtained in step (i) are melted in an extruder to obtain small particles of the mixture, Recycling methods, including those mentioned above.

30. A method for recycling a textile comprising at least one elastic yarn (20, 21, 22) of claim 21 and preferably at least one thermoplastic yarn made of polyamide, comprising the following steps: (i) The step of shredding the textile to obtain small pieces, (ii) A step in which the small pieces obtained in step (i) are melted in an extruder to obtain small particles of the mixture, Recycling methods, including those mentioned above.

31. A recycling method according to claim 30, Next step (iii), (iii) A step of spinning recycled yarn by melt extrusion of the small grains obtained in step (ii), A recycling method characterized by further comprising the following.

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