Differential shrinkage elastic composite filament DTY fiber and elasticizing processing method thereof

Abstract

According to the different-shrinkage elastic composite filament DTY fiber and the elasticity enhancing processing method thereof, the semi-dull polyester POY, the T8 modified polyester POY and the modified polyester FDY are selected and combined, the processing path is optimized, and the prepared composite filament fiber has bulkiness, high elasticity and different-shrinkage effects. Through introduction of T8 modified polyester and processing of the T8 modified polyester in a low-temperature first hot box, untwisting and orientation are completed, and the high-elasticity and soft characteristics are stimulated. Meanwhile, the second hot box is closed, so that the two false-twisted POY filaments are naturally and slowly cooled and shaped in the closed channel, damage to a T8 polyester curling structure is avoided, the high shrinkage potential of the T8 polyester is reserved, and meanwhile energy conservation and consumption reduction are achieved. Besides, the FDY is introduced through an independent low-tension path, and is combined with the POY at an outlet through a bottom net technology, so that the strength loss of the FDY caused by excessive drafting or high-temperature treatment is avoided, and the mechanical property of a final product is guaranteed while a unique three-dimensional texture is formed.

Description

Technical Field

[0001] This invention relates to the field of DTY fiber materials, and in particular to a differential shrinkage elastic composite yarn DTY fiber and its texturing process. Background Technology

[0002] Polyester stretched textured yarn (DTY) is an important raw material in the textile industry, widely used in apparel, home textiles, and other industries due to its excellent elasticity and bulkiness. However, traditional DTY production generally suffers from high processing energy consumption and high oven temperature requirements. Furthermore, DTY fibers made from conventional polyester still fall short in terms of elasticity and softness, making it difficult to meet the growing market demand for high-end functional textiles.

[0003] To improve fiber properties, the industry has begun to adopt composite processing technologies, such as combining pre-oriented yarn (POY) with fully drawn yarn (FDY) to combine the high elasticity of POY with the high strength of FDY. T8 modified polyester, as a novel material, has attracted attention due to its properties such as normal pressure dyeability, high elasticity, and softness. Its molecular structure makes it more suitable for processing and setting under relatively low-temperature conditions. This provides a material basis for the development of low-temperature energy-saving high-elasticity composite yarns.

[0004] However, existing composite texturing technologies typically require FDY to undergo high-temperature heat treatment in a hot box, which easily leads to FDY molecular chain degradation and strength loss. Furthermore, the low-temperature processing characteristics of T8 polyester are incompatible with the high-temperature processing of conventional polyester. Using traditional processes cannot fully utilize its high elasticity and softness advantages; instead, the mismatch in processing results in performance degradation. Therefore, how to achieve low-temperature processing of T8 polyester on conventional texturing equipment while avoiding damage to FDY strength and simultaneously achieving a differential shrinkage and bulky effect has become a pressing technical challenge in this field. Summary of the Invention

[0005] In view of the above problems, a differential shrinkage elastic composite yarn (DTY) fiber and its texturing process are proposed to overcome or at least partially solve the above problems, including:

[0006] A texturing process for DTY (different shrinkage elastic composite yarn) is disclosed. The method involves using semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn as raw materials, and feeding, heating, cooling, false twisting, bottom weaving, and winding to obtain DTY fiber. In the heating step, the temperature of the first heating box is controlled at 160-180℃. In the bottom weaving step, the second heating box is kept closed and the modified polyester FDY yarn is independently introduced through the lower heating box guide tube.

[0007] Optionally, the specifications of semi-dull polyester POY yarn are 85 dtex / 144f, T8 modified polyester POY yarn is 135 dtex / 48f, and modified polyester FDY yarn is 33 dtex / 12f.

[0008] Optionally, the texturing machine model is TMT-1500 strand texturing machine, which is equipped with a wire guide, a lower heating box wire guide tube and a bottom mesh pipe.

[0009] Optional, specifically including the following steps:

[0010] 1) Feeding: Semi-dull polyester POY yarn is introduced into the texturing machine through a yarn guide, and T8 modified polyester POY yarn is introduced into the texturing machine through a yarn guide.

[0011] 2) Heating: Semi-dull polyester POY yarn and T8 modified polyester POY yarn are heated in the first heating box, and the temperature of the first heating box is controlled at 160-180℃;

[0012] 3) Cooling: Allow the heated semi-dull polyester POY yarn and T8 modified polyester POY yarn to cool naturally;

[0013] 4) False twist: The cooled semi-dull polyester POY yarn and T8 modified polyester POY yarn enter the false twist zone and are false twisted using a 1-5-1 disc combination; among them, the semi-dull polyester POY yarn uses S twist and the T8 modified polyester POY yarn uses Z twist.

[0014] 5) Bottom Net: Keeping the second heating box closed, the semi-dull polyester POY yarn and T8 modified polyester POY yarn after false twisting enter the second heating box; the modified polyester FDY yarn then enters the lower heating box guide tube, which is installed parallel to the second heating box, after passing through the auxiliary roller. Subsequently, the semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn are combined in the bottom net pipe at the outlet of the second heating box for netting. After passing through the bottom net nozzle, compressed air blows regular knots onto the yarn; during the merging process, a bottom net network pressure of 0.31MPa is applied to the merged yarn.

[0015] 6) Winding: The combined filaments are wound at a constant winding speed to obtain heteroshrunk elastic composite yarn DTY fiber.

[0016] Optionally, the winding speed is 500-600m / min, the tension at the front of the bottom web is 3-7cN, the tension at the back of the bottom web is 5-15cN, the tension introduced by the modified polyester FDY yarn is 4-8cN, and the winding tension is 20-30cN.

[0017] Optionally, the false twist disc is a composite ceramic disc with a microtextured surface, wherein the microtexture is a spiral microgroove with a depth of 10-20 μm.

[0018] Optionally, before the feeding step, the pre-tension of the semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn may be adjusted, and static electricity may be eliminated.

[0019] Optionally, the first heating box adopts a composite heating method of microwave-assisted heating and hot plate heat transfer heating, wherein the microwave frequency is 2.45 GHz and the power is 3-5 kW.

[0020] Optionally, the jet direction of the bottom mesh nozzle is at a variable angle of 15-30° with the direction of the yarn running, and the oscillation frequency of the bottom mesh nozzle is 5-15Hz.

[0021] A type of heteroshrunk elastic composite yarn DTY fiber, which is obtained by processing by any of the methods described above.

[0022] This invention provides a differential shrinkage elastic composite yarn (DTY) and its texturing process. It combines three raw materials—semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn—and optimizes the processing path to produce a composite yarn that combines bulkiness, high elasticity, and differential shrinkage. The introduction of T8 modified polyester and its processing in a low-temperature first heating chamber completes untwisting and orientation, stimulating its high elasticity and softness. Simultaneously, the second heating chamber is closed, allowing the two false-twisted POY yarns to naturally and slowly cool and set in a closed channel, avoiding damage to the crimped structure of the T8 polyester, preserving its high shrinkage potential, and achieving energy saving and consumption reduction. Furthermore, FDY is introduced through an independent low-tension path and merged with the POY yarn at the exit using a bottom mesh technology, avoiding strength loss caused by excessive stretching or high-temperature treatment of FDY, thus ensuring the mechanical properties of the final product while forming a unique three-dimensional texture. Attached Figure Description

[0023] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of a texturing method for DTY fiber, a composite yarn with varying shrinkage elasticity, provided in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the modified texturing machine component provided in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the microtexture of the false twist disc provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram illustrating the working principle of the bottom mesh nozzle provided in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the composite filament structure provided in an embodiment of the present invention. Detailed Implementation

[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a texturing method for DTY (dithermal elastic composite yarn) fibers, comprising:

[0031] Using semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn as raw materials, DTY fiber with differential shrinkage elasticity is obtained through feeding, heating, cooling, false twisting, bottom web formation, and winding. In the heating step, the temperature of the first heating box is controlled at 160-180℃. In the bottom web formation step, the second heating box is kept closed and the modified polyester FDY yarn is independently introduced through the lower heating box guide tube.

[0032] Among them, the specifications of semi-dull polyester POY yarn are 85dtex / 144f, T8 modified polyester POY yarn are 135dtex / 48f, and modified polyester FDY yarn are 33dtex / 12f.

[0033] The texturing machine is model TMT-1500 twisted texturing machine. The texturing machine is equipped with a wire guide, a lower heating box wire guide tube, and a bottom mesh pipe.

[0034] Specifically, the following steps are included:

[0035] 1) Feeding: Semi-dull polyester POY yarn is introduced into the texturing machine through a yarn guide, and T8 modified polyester POY yarn is introduced into the texturing machine through a yarn guide.

[0036] 2) Heating: Semi-dull polyester POY yarn and T8 modified polyester POY yarn are heated in the first heating box, and the temperature of the first heating box is controlled at 160-180℃;

[0037] 3) Cooling: Allow the heated semi-dull polyester POY yarn and T8 modified polyester POY yarn to cool naturally;

[0038] 4) False twist: The cooled semi-dull polyester POY yarn and T8 modified polyester POY yarn enter the false twist zone and are false twisted using a 1-5-1 disc combination; among them, the semi-dull polyester POY yarn uses S twist and the T8 modified polyester POY yarn uses Z twist.

[0039] 5) Bottom Net: Keeping the second heating box closed, the semi-dull polyester POY yarn and T8 modified polyester POY yarn after false twisting enter the second heating box; the modified polyester FDY yarn then enters the lower heating box guide tube, which is installed parallel to the second heating box, after passing through the auxiliary roller. Subsequently, the semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn are combined in the bottom net pipe at the outlet of the second heating box for netting. After passing through the bottom net nozzle, compressed air blows regular knots onto the yarn; during the merging process, a bottom net network pressure of 0.31MPa is applied to the merged yarn.

[0040] 6) Winding: The combined filaments are wound at a constant winding speed to obtain heteroshrunk elastic composite yarn DTY fiber.

[0041] The specific technical details of each process are as follows:

[0042] I. Equipment and Raw Material Preparation

[0043] Reference Figure 1 , Figure 2 This embodiment of the invention is carried out on a TMT-1500 stranding and texturing machine equipped with specific modified components. The specific modifications include the addition of a dedicated wire guide, an independent lower heat box wire guide tube installed in parallel with the second heat box, and a bottom mesh pipe and nozzle system. The bottom mesh nozzle can be a slit nozzle with an orifice diameter of 1.2 mm to ensure the uniformity and stability of the mesh dots.

[0044] The raw materials used are as follows:

[0045] Semi-dull polyester POY yarn: 85 dtex / 144f. This raw material primarily provides the yarn's skeleton structure and basic strength, with an intrinsic viscosity of 0.65 ± 0.02 dl / g.

[0046] T8 modified polyester POY yarn: specifications are 135 dtex / 48f. Due to its unique copolymer components, this T8 modified polyester has the characteristics of normal pressure boiling dyeing, high elasticity and low temperature setting, and its intrinsic viscosity can be 0.72±0.02 dl / g.

[0047] Modified polyester FDY yarn: specification 33dtex / 12f. This fully drawn yarn has high orientation and crystallinity, and high breaking strength. In this invention, its main function is to provide additional support and hand feel adjustment. Its intrinsic viscosity can be 0.58±0.02 dl / g.

[0048] II. Texturing Process Flow

[0049] 1. Feeding

[0050] The semi-dull polyester POY spools and the T8 modified polyester POY spools are placed on the raw yarn rack, respectively. The semi-dull polyester POY yarn is introduced through the existing standard yarn guide of the texturing machine, while the T8 modified polyester POY yarn is introduced through an additional yarn guide. The purpose of this additional yarn guide is to precisely control the yarn path of the T8 polyester, reducing frictional damage to the equipment due to its smoother and more wear-resistant surface. During this process, the feeding tension of the two POY yarns can be monitored and controlled to remain stable between 3-5 cN using an online tension sensor, ensuring that the yarns enter the first heating box smoothly and without vibration, thus reducing fuzz and breakage rates from the source.

[0051] In a preferred embodiment of the present invention, before the feeding step, the method further includes: pre-tensioning the semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn, and performing static electricity elimination treatment.

[0052] It is understandable that differences in winding hardness between different bobbins can lead to fluctuations in unwinding tension. Pre-tensioning can eliminate this initial unevenness, providing a constant and consistent starting point for all subsequent processing stages. Furthermore, for T8 modified POY yarn with a high potential shrinkage rate, excessively high initial tension can cause uncontrollable pre-stretching before entering the hot box, resulting in uneven fineness and loss of elasticity in the final product. Low and stable tension effectively protects its structure. Pre-tensioning can effectively avoid these issues.

[0053] In practice, after each type of raw material filament is unwound from the bobbin, it can first pass through an independent adjustable tension controller, such as a magnetically damped or pneumatic tensioner. Through precise adjustment, the initial unwinding tension of the semi-dull polyester POY filament and the T8 modified polyester POY filament is set and stabilized between 2.0-3.5 cN, while the initial unwinding tension of the modified polyester FDY filament is set between 3.0-4.5 cN.

[0054] In addition, to prevent the static-charged filaments from attracting dust and oil from the air and ultimately being trapped in the network dots, forming defects, and to prevent the filaments from "scattering" due to the repulsion of like charges after being charged, resulting in increased fuzz or even breakage, this embodiment of the invention also performs static elimination treatment on the filaments.

[0055] Specifically, after pre-tension control is completed, the three types of yarns (i.e., semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn) pass through an anti-static yarn guide or an ion wind static eliminator before entering the yarn guiding system. This device continuously generates positive and negative ion flows to neutralize the static charge generated by friction during the high-speed operation of the polyester yarn.

[0056] 2. Heating

[0057] Two POY yarns are fed into the first heating chamber in parallel for heating and deformation. The first heating chamber can be electrically heated, and its temperature is precisely set and controlled at 170℃ (it can be finely adjusted within the range of 160-180℃ depending on the batch). At this temperature, the molecular chains of T8 modified polyester can obtain sufficient energy to undergo disorientation and recrystallization, and its potential high elasticity is fully activated; at the same time, this temperature is also sufficient to cause the necessary plastic deformation of conventional semi-dull polyester POY, preparing it for subsequent false twisting, while being much lower than that of traditional processes (usually 190-210℃), achieving energy saving.

[0058] In an embodiment of the present invention, the first hot box may also employ a combined heating method of microwave-assisted heating and hot plate heat transfer, wherein the microwave frequency is 2.45 GHz and the power is 3-5 kW.

[0059] Understandably, microwave energy can penetrate the surface of the yarn and act directly on the polyester molecules, heating the yarn simultaneously and uniformly from the inside out. This heating mode overcomes the temperature gradient problem inherent in traditional heat conduction methods, which involve heating from the surface inwards. It significantly shortens the heating time required for the yarn to reach the predetermined deformation temperature, resulting in a substantial improvement in thermal efficiency.

[0060] Furthermore, the molecular structure of T8 modified polyester makes it more efficient at absorbing microwave energy than conventional polyester. By precisely controlling the microwave power, the T8 component can be activated more efficiently, ensuring that its macromolecular chains obtain sufficient energy at a relatively lower overall temperature to complete disorientation and rearrangement, thereby more fully stimulating its elastic potential while further avoiding the risk of overheating.

[0061] 3. Cooling

[0062] After leaving the first heating chamber, the two thermoplastic filaments immediately enter the cooling zone. Natural cooling with ambient air at room temperature can be used, with the ambient temperature controlled at 25±3℃. The purpose of cooling is to lower the temperature of the heated and deformed filaments below their glass transition temperature, freezing and stabilizing their molecular chain structure, thereby fixing the deformed state. Uniform and sufficient cooling is crucial to ensuring stable false twisting results and reducing defects.

[0063] 4. False twist

[0064] The cooled filament enters the false twister. In this embodiment of the invention, a friction-type false twister can be used, with a 1-5-1 disc configuration: one driving disc, five inert discs, and one driving disc. The disc material can be polyurethane. The rotational speed of the false twister can be automatically adjusted according to the winding speed. During this process:

[0065] Semi-dull polyester POY yarn is subjected to S-twist.

[0066] T8 modified polyester POY yarn is subjected to Z-twist.

[0067] This alternating twist design allows the residual torque of the two filaments to cancel each other out when they are subsequently joined, effectively preventing kinking and uneven curling in the final yarn.

[0068] Reference Figure 3 In a preferred embodiment of the present invention, the false twist disc is a composite ceramic disc with a microtextured surface, wherein the microtexture is a spiral microgroove with a depth of 10-20 μm.

[0069] It is understandable that the spiral microgrooves are designed in synergy with the disc rotation direction and the filament travel path, which can significantly enhance the grip of the disc surface on the filament, ensuring efficient and stable transfer of twist to the filament and reducing stiff or fuzzy filaments caused by twist transfer failure. Moreover, the unique spiral texture can also guide airflow, forming an extremely thin air film when the disc rotates at high speed, partially replacing direct solid friction, thereby effectively reducing the coefficient of friction between the filament and the disc, reducing wear and damage to the filament, and helping to protect the delicate surface structure of T8 polyester and maintain its soft feel. In addition, this microgroove structure helps to disperse and dissipate the heat generated by friction, avoiding thermal damage or uneven performance of the filament that may be caused by local overheating.

[0070] The use of composite ceramic materials gives the disks extremely high wear resistance and thermal stability, ensuring that the microtexture can maintain the consistency of its shape and function even under long-term high-speed operation, extending the service life of key consumables and reducing production and maintenance costs.

[0071] 5. Bottom mesh

[0072] The two false-twisted POY yarns are then placed in a second heating chamber with the heating function turned off. Although the second heating chamber is closed, it provides a sealed, insulated space where the two POY yarns can cool naturally and slowly. This process helps T8 polyester form a more stable crystalline structure, maximizing the preservation of its high shrinkage and crimp elasticity, and avoiding damage to its structure caused by high-temperature setting.

[0073] Meanwhile, the modified polyester FDY filament is drawn from another filament rack and passes through a separate auxiliary roller. This roller is designed to provide a low tension pull of 4-8 cN for the FDY filament, ensuring that the FDY is not accidentally stretched during introduction and thus does not lose its high-strength properties. Subsequently, the FDY filament is precisely fed through a lower heat box guide tube installed parallel to the second heat box. This guide tube is an independent physical channel that allows the FDY to bypass the heat treatment in the heat box, thereby preserving its original mechanical properties.

[0074] At the outlet of the second heating chamber, a three-hole guide gathers three filaments (S-twist POY, Z-twist POY, and FDY) together and immediately guides them into the bottom web nozzle. Compressed air is steadily ejected from the nozzle slit at a pressure of 0.31 MPa via a pressure regulating valve, providing a uniform and continuous spray to the gathered filaments. The airflow generates intense turbulence on the filaments, causing the individual filaments to entangle and form periodic, robust network nodes. The appearance of these network nodes greatly enhances the cohesion between the three heterogeneous filaments, making them a unified whole, facilitating subsequent weaving processes, and also giving the yarn a unique three-dimensional style and hand feel. During this process, the tension before the web generator is controlled at 3-7 cN, and the tension after the web generator is controlled at 5-15 cN.

[0075] Reference Figure 4 In a preferred embodiment of the present invention, the jet direction of the bottom mesh nozzle is at a variable angle of 15-30° with the running direction of the filament, and the oscillation frequency of the bottom mesh nozzle is 5-15Hz.

[0076] Understandably, in practical applications, the compressed air injection direction of the bottom mesh nozzle is not fixed, but rather set to form a variable angle of 15° to 30° with the direction of the wire's movement. This angle can be dynamically adjusted in real time via a servo control system. For example, when the processing speed increases or the raw material batch changes, the operator can adjust the angle from 20° to 25° to achieve the optimal balance between mesh performance and tension fluctuations. Simultaneously, the bottom mesh nozzle does not operate statically, but is mounted on a high-frequency piezoelectric ceramic drive device, enabling high-speed, micro-amplitude lateral oscillation at a frequency of 5 Hz to 15 Hz. The oscillation frequency can be controlled in conjunction with changes in mesh pressure.

[0077] Traditional vertical jetting (90° angle) delivers direct impact, easily scratching the surface of the monofilament. Adjusting the jetting angle to an acute angle (15-30°) transforms the compressed airflow's effect on the filament from a direct impact to a combination of shearing and rubbing. This not only fully and evenly entangles the FDY and POY filaments together, forming a strong network, but also significantly reduces frictional damage to the monofilament surface, particularly protecting the soft feel of T8 polyester.

[0078] Furthermore, a fixed nozzle produces network knots with a perfectly consistent cycle, which can manifest as regular defects in subsequent dyeing and weaving processes. By oscillating the nozzle at a frequency of 5-15 Hz, the fixed cycle of network knot formation is disrupted, causing its distribution to become more random. This significantly improves the evenness of the final fiber, resulting in a more uniform appearance and effectively avoiding problems such as dyeing streaks caused by the regular distribution of network knots.

[0079] The variable jet angle, combined with the high-speed oscillation of the nozzle, means that the point of application of the high-pressure airflow is no longer limited to a fixed side of the filament bundle, but rather forms a dynamic, rotating entanglement field in the space surrounding the filaments. The airflow acts on the filament bundle intermittently from different angles, causing each filament to undergo complex spatial displacement and interweaving, thereby forming a more stable and uniformly distributed three-dimensional network structure, significantly improving the network point strength.

[0080] 6. Winding

[0081] Finally, the composite yarn, after being twisted together via a network, passes through a yarn breakage detector and an oiling device, and is then wound into a bobbin by a winding head at a constant speed of 500-600 m / min. The winding tension is maintained at 20-30 cN by a tension control system to ensure that the package has moderate hardness, a flat structure, and is easy to transport and unwind.

[0082] III. Product Performance Testing

[0083] Reference Figure 5 In the embodiments of the present invention, the breaking strength and breaking elongation are tested in accordance with the standard GB / T14344-2022 Test Method for Tensile Properties of Chemical Fiber Filaments.

[0084] The performance of the differential shrinkage elastic composite yarn DTY fiber prepared according to the above process was tested, and the results are as follows:

[0085] Fineness: 175±3 dtex;

[0086] Fracture strength ≥ 3.0 cN / dtex;

[0087] Elongation at break: 15.0-20.0%.

[0088] This invention combines three raw materials—semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn—and optimizes their processing path to produce composite fibers that possess both bulkiness, high elasticity, and differential shrinkage. The introduction of T8 modified polyester and its processing in a low-temperature first heating chamber completes untwisting and orientation, stimulating its high elasticity and softness. Simultaneously, the second heating chamber is closed, allowing the two false-twisted POY yarns to naturally and slowly cool and set within a sealed channel, avoiding damage to the T8 polyester's crimped structure, preserving its high shrinkage potential, and achieving energy conservation and consumption reduction. Furthermore, FDY is introduced through an independent low-tension path and merged with the POY yarn at the outlet using a bottom mesh technology, avoiding strength loss caused by excessive stretching or high-temperature treatment of the FDY, thus ensuring the mechanical properties of the final product while forming a unique three-dimensional texture.

[0089] This invention also provides a heteroswellable elastic composite yarn (DTY fiber), which is obtained by the method described above.

[0090] The above provides a detailed description of the DTY fiber with heteroswell elastic composite yarn and its texturing process. Specific examples have been used to illustrate the principle and implementation of the invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the invention. Therefore, the content of this specification should not be construed as a limitation of the invention.

Claims

1. A texturing process for DTY (dielectric-shrinkage elastic composite yarn), characterized in that, The method is as follows: using semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn as raw materials, the differential shrinkage elastic composite yarn DTY fiber is obtained through feeding, heating, cooling, false twisting, bottom web formation, and winding. In the heating step, the temperature of the first heating box is controlled at 160-180℃, and in the bottom web formation step, the second heating box is kept closed and the modified polyester FDY yarn is independently introduced through the lower heating box guide tube.

2. The method according to claim 1, characterized in that, The semi-dull polyester POY yarn has a specification of 85 dtex / 144f, the T8 modified polyester POY yarn has a specification of 135 dtex / 48f, and the modified polyester FDY yarn has a specification of 33 dtex / 12f.

3. The method according to claim 2, characterized in that, in, The texturing machine is a TMT-1500 strand texturing machine, which is equipped with a wire guide, a lower heating box wire guide tube, and a bottom mesh pipe.

4. The method according to any one of claims 1 to 3, characterized in that, Specifically, the following steps are included: 1) Feeding: The semi-dull polyester POY yarn is introduced into the texturing machine through a yarn guide, and the T8 modified polyester POY yarn is introduced into the texturing machine through a yarn guide; 2) Heating: The semi-dull polyester POY yarn and the T8 modified polyester POY yarn are heated in the first heating box, and the temperature of the first heating box is controlled at 160-180℃; 3) Cooling: Allow the heated semi-dull polyester POY yarn and T8 modified polyester POY yarn to cool naturally; 4) False twist: The cooled semi-dull polyester POY yarn and T8 modified polyester POY yarn enter the false twist zone and are false twisted using a disc assembly 1-5-1; wherein, the semi-dull polyester POY yarn adopts an S twist and the T8 modified polyester POY yarn adopts a Z twist. 5) Bottom Net: Keeping the second heating box closed, the semi-dull polyester POY yarn and T8 modified polyester POY yarn, after false twisting, enter the second heating box; the modified polyester FDY yarn, after passing through the auxiliary roller, enters the lower heating box guide tube installed parallel to the second heating box. Subsequently, the semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn are combined in the bottom net pipe at the outlet of the second heating box for netting. After passing through the bottom net nozzle, compressed air blows regular knots onto the yarn; during the merging process, a bottom net network pressure of 0.31 MPa is applied to the merged yarn; 6) Winding: The combined filaments are wound at a constant winding speed to obtain the heteroshrunk elastic composite yarn DTY fiber.

5. The method according to claim 4, characterized in that, in, The winding speed is 500-600m / min, the tension at the front of the bottom web is 3-7cN, the tension at the back of the bottom web is 5-15cN, the tension introduced by the modified polyester FDY yarn is 4-8cN, and the winding tension is 20-30cN.

6. The method according to claim 4, characterized in that, The false twist disc is a composite ceramic disc with a microtextured surface, wherein the microtexture is a spiral microgroove with a depth of 10-20 μm.

7. The method according to claim 6, characterized in that, Before the feeding step, the process also includes: pre-tensioning the semi-dull polyester POY yarn, T8 modified polyester POY yarn, and modified polyester FDY yarn, and performing static electricity elimination treatment.

8. The method according to claim 7, characterized in that, The first hot box adopts a composite heating method of microwave-assisted heating and hot plate heat transfer heating, wherein the microwave frequency is 2.45 GHz and the power is 3-5 kW.

9. The method according to claim 8, characterized in that, The jet direction of the bottom mesh nozzle is at a variable angle of 15-30° with the direction of the wire running, and the oscillation frequency of the bottom mesh nozzle is 5-15Hz.

10. A type of heteroswellable elastic composite yarn (DTY fiber), characterized in that, It is obtained by the method described in any one of claims 1-9.

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