Preparation method of high-elasticity and durable polyester fiber

Abstract

The application discloses a preparation method of high-elasticity durable polyester fiber, which comprises the following steps: performing a winding treatment on polyester raw material silk; performing low-temperature plasma surface modification on the fiber after the winding treatment; performing twisting on the modified fiber, and introducing phase change microcapsules into the fiber tows through an interlacing nozzle in the twisting process, so that the microcapsules are physically embedded between the fiber filaments; placing the twisted fiber in a supercritical carbon dioxide fluid for heat setting treatment; and finally obtaining the high-elasticity durable polyester fiber through a cylinder reversing treatment. Through the synergistic effect of the low-temperature plasma modification, the microcapsule embedding in the twisting and the supercritical carbon dioxide heat setting, the fiber has high elasticity and intelligent temperature adjusting functions, the elastic recovery rate is higher than 94%, and the retention rate of the microcapsules is higher than 90% after 20 times of washing. The application has simple process, is environment-friendly and waste water-free, and the obtained fiber is suitable for high-grade garment fabrics and functional lining.

Description

Technical Field

[0001] This invention belongs to the field of polymer preparation technology, and particularly relates to a method for preparing high-elasticity and durable polyester fiber. Background Technology

[0002] Polyester fiber, due to its high strength, good elasticity, and strong abrasion resistance, is widely used in the production of clothing fabrics and linings. Existing technologies for improving the elasticity of polyester fibers mainly include increasing fiber twist and chemical cross-linking modification. Increasing twist physically induces a crimped structure in the fiber, thus imparting elasticity; chemical cross-linking modification introduces cross-linking agents to form a network structure of fiber molecular chains, improving elastic recovery. Furthermore, to impart functionality to polyester fibers, existing technologies typically employ finishing processes to apply functional substances, such as immersing the fiber in a treatment solution containing phase change microcapsules, antibacterial agents, or UV stabilizers, followed by a pad-drying process to adhere the functional substances to the fiber surface. The heat setting process usually uses steam or hot air in an electric steamer to eliminate internal fiber stress and stabilize the fiber structure.

[0003] However, existing technologies have the following shortcomings: simply increasing twist leads to excessive internal stress in the fiber, which easily causes kinking and entanglement in subsequent processing, affecting weaving efficiency and product quality; chemical cross-linking modification processes are complex and may affect the fiber's hand feel and dyeing properties. Functional substances applied through finishing methods only adhere to the fiber surface, exhibiting weak bonding with the fiber body and easily detaching after repeated washing, resulting in poor functional durability. Traditional steam heat setting processes are energy-intensive and generate large amounts of wastewater, failing to meet environmental protection requirements; simultaneously, the high temperature and moisture of steam may damage functional substances, limiting the development of functional fibers. Existing methods struggle to simultaneously address fiber elasticity, functional durability, and environmental friendliness in the same process flow, typically requiring multiple overlapping processes, resulting in cumbersome procedures and unsatisfactory results. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for preparing high-elasticity and durable polyester fiber, which solves the problems of poor elasticity and durability of polyester fiber, easy loss of functional materials and poor environmental friendliness of the process in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a high-elasticity, durable polyester fiber includes the following steps: (1) Winding: The polyester raw yarn is wound to make it suitable for subsequent processing by changing the yarn spool packaging. (2) Surface modification: The fibers after winding are subjected to low-temperature plasma treatment, and high-energy particles are used to bombard the fiber surface to form micro-pits and introduce polar groups. (3) Twisting and microcapsule embedding: The surface-modified fibers are twisted, and phase change microcapsules are introduced into the fiber bundle through the interlacing nozzle during the twisting process. The mechanical cohesion force generated by twisting is used to physically embed the microcapsules between the fiber monofilaments. (4) Heat setting: The twisted fiber is placed in supercritical carbon dioxide fluid for heat setting treatment. The high permeability of supercritical carbon dioxide is used to eliminate the internal stress of the fiber and stabilize the twisted structure. (5) Rewinding: The heat-set fibers are rewinded, and the tension is adjusted to make the filaments uniform and the roll size is increased to obtain high-elasticity and durable polyester fibers.

[0006] Preferably, the winding speed of the winding in step (1) is 400-600 meters / minute.

[0007] Preferably, in step (2), the low-temperature plasma treatment uses air, oxygen or nitrogen as the working gas, the treatment power is 50-300W, and the treatment time is 30 seconds to 5 minutes.

[0008] Preferably, the phase change microcapsules in step (3) have a particle size of 0.5-10 micrometers and are paraffin microcapsules.

[0009] Preferably, the twist in step (3) is 600-1200 twists / meter, and the air pressure of the interlacing nozzle is 0.2-0.6MPa.

[0010] Preferably, in step (4), the temperature of the supercritical carbon dioxide fluid treatment is 100-140℃, the pressure is 10-30MPa, the treatment time is 20-60 minutes, and the density of the supercritical carbon dioxide fluid is 0.4-0.9 g / cm³.

[0011] Preferably, the supercritical carbon dioxide fluid in step (4) contains an environmentally friendly additive, which is a non-toxic plasticizer or dispersant, and its addition amount accounts for 0.1%-5% of the total mass of the supercritical carbon dioxide fluid.

[0012] Preferably, the interlacing nozzle in step (3) is located in front of the twisting device or inside the twisting device.

[0013] Preferably, the low-temperature plasma treatment in step (2) forms polar groups on the fiber surface that enhance the fiber's affinity for the microcapsules.

[0014] Preferably, the supercritical carbon dioxide fluid in step (4) penetrates the amorphous region of the fiber during the heat setting process, while the environmentally friendly additives are evenly distributed inside the fiber.

[0015] The technical effects and advantages of the method for preparing high-elasticity and durable polyester fiber of the present invention are as follows: 1. This invention, through the synergistic effect of low-temperature plasma surface modification, twisting and embedding phase change microcapsules, and supercritical carbon dioxide-assisted heat setting, simultaneously endows polyester fibers with high elasticity, durability, and intelligent temperature regulation functions in the same process, realizing the multi-functional integration of the fiber body and avoiding the defects of easy loss of functional materials and poor durability in traditional finishing methods.

[0016] 2. The polyester fiber prepared by this invention has excellent high elasticity, with an elastic recovery rate of over 94%, and can still maintain a stable elastic structure after multiple stretching, exhibiting strong durability; at the same time, the phase change microcapsules physically embedded inside the fiber endow it with intelligent temperature regulation function, and the microcapsule retention rate reaches over 90% after 20 standard water washes, ensuring a long-lasting and stable temperature regulation function.

[0017] 3. This invention uses supercritical carbon dioxide fluid to replace traditional steam for heat setting. The process is completely waterless, the carbon dioxide can be recycled and reused, and there is no wastewater discharge, which meets the requirements of green environmental protection. At the same time, the low surface tension and high diffusion characteristics of supercritical fluid enable it to complete the setting under mild conditions, avoiding the damage of high temperature to the microcapsule structure.

[0018] 4. The invention has a simple process flow and close connection between each step. It can be realized by adding only plasma treatment device and supercritical treatment device to the conventional chemical fiber production equipment. The equipment investment is moderate and it is suitable for large-scale industrial production. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for preparing high-elasticity and durable polyester fiber proposed in this invention. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include," "contain," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "includes..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0022] refer to Figure 1 This invention discloses a method for preparing high-elasticity and durable polyester fiber, comprising the following steps: (1) Winding: The polyester raw yarn is wound to make it suitable for subsequent processing by changing the yarn spool packaging. (2) Surface modification: The fibers after winding are subjected to low-temperature plasma treatment, and high-energy particles are used to bombard the fiber surface to form micro-pits and introduce polar groups. (3) Twisting and microcapsule embedding: The surface-modified fibers are twisted, and phase change microcapsules are introduced into the fiber bundle through the interlacing nozzle during the twisting process. The mechanical cohesion force generated by twisting is used to physically embed the microcapsules between the fiber monofilaments. (4) Heat setting: The twisted fiber is placed in supercritical carbon dioxide fluid for heat setting treatment. The high permeability of supercritical carbon dioxide is used to eliminate the internal stress of the fiber and stabilize the twisted structure. (5) Rewinding: The heat-set fibers are rewinded, and the tension is adjusted to make the filaments uniform and the roll size is increased to obtain high-elasticity and durable polyester fibers.

[0023] In step (1), the winding speed of the yarn is 400-600 meters per minute. This speed range is determined based on the physical properties of polyester filament and the stability of equipment operation: below 400 meters per minute, the production efficiency is too low, and above 600 meters per minute, the yarn tension fluctuation increases, which can easily cause yarn breakage and fuzz, affecting the quality of subsequent processing.

[0024] In step (2), the low-temperature plasma treatment uses air, oxygen, or nitrogen as the working gas, with a treatment power of 50-300W and a treatment time of 30 seconds to 5 minutes. The selection of the power and time range is based on the following: when the power is below 50W, the high-energy particles lack sufficient energy, making it difficult to form effective etching on the fiber surface and introduce a sufficient density of polar groups; when the power is above 300W, overtreatment may damage the fiber's strength. A treatment time shorter than 30 seconds is insufficient, while a time longer than 5 minutes reduces efficiency and poses a risk of overheating.

[0025] The phase change microcapsules mentioned in step (3) have a particle size of 0.5-10 micrometers, and the phase change microcapsules are paraffin microcapsules. The selection of the particle size range is based on the following considerations: when the particle size is less than 0.5 micrometers, the microcapsules are too light and easily disperse during spraying, making it difficult to accurately position them in the fiber bundle; when the particle size is greater than 10 micrometers, the microcapsules cannot pass smoothly through the micro-channels of the interlacing nozzle, or even if they do pass through, they are difficult to be effectively held by the monofilaments. The phase change temperature range of the paraffin microcapsules is 28-32℃, which is close to the human body's comfortable temperature range, enabling intelligent temperature regulation functions of heat absorption and release.

[0026] In step (3), the twist is 600-1200 twists / meter, and the air pressure of the interlacing nozzle is 0.2-0.6 MPa. The twist range is determined based on the following: below 600 twists / meter, the cohesion between fibers is insufficient, microcapsules are easily detached, and the fiber elasticity recovery rate is low; above 1200 twists / meter, the internal stress of the fiber is too high, increasing the difficulty of subsequent shaping and potentially affecting the feel. The air pressure range is determined based on the following: below 0.2 MPa, the atomization of the treatment liquid is insufficient, and the microcapsules are unevenly distributed; above 0.6 MPa, excessive airflow may disrupt fiber arrangement and affect the uniformity of twisting.

[0027] In step (4), the supercritical carbon dioxide fluid treatment temperature is 100-140℃, the pressure is 10-30MPa, the treatment time is 20-60 minutes, and the density of the supercritical carbon dioxide fluid is 0.4-0.9 g / cm³. The selection of temperature and pressure conditions is based on the following: the critical temperature of carbon dioxide is 31.1℃, and the critical pressure is 7.38MPa. The temperature and pressure range selected in this invention ensures that the carbon dioxide is in a supercritical state. When the temperature is below 100℃, the fiber molecular chain movement is insufficient, resulting in poor shaping effect; when the temperature is above 140℃, it may affect the thermal stability of the microcapsules. When the pressure is below 10MPa, the supercritical fluid density is too low, resulting in insufficient permeability; when the pressure is above 30MPa, the equipment requirements are too high, leading to reduced economy. When the treatment time is less than 20 minutes, the shaping is insufficient; when it is longer than 60 minutes, the efficiency decreases. The density range of 0.4-0.9 g / cm³ corresponds to the selected temperature and pressure conditions. Within this density range, supercritical carbon dioxide possesses both good permeability and dissolving ability.

[0028] In step (4), the supercritical carbon dioxide fluid contains environmentally friendly additives, which are non-toxic plasticizers or dispersants, and their addition amount accounts for 0.1%-5% of the total mass of the supercritical carbon dioxide fluid. The role of the environmentally friendly additives is to promote the rearrangement and orientation of polyester molecular chains during the heat setting process, thereby improving the setting efficiency. The basis for determining the addition amount range is as follows: when it is less than 0.1%, the effect of the additives is not obvious and it is difficult to effectively promote the movement of molecular chains; when it is more than 5%, the additives may remain inside the fiber, affecting the fiber purity and subsequent processing performance, while increasing the cost. Plasticizers include tributyl citrate, acetylated triethyl citrate, etc.; dispersants include polyether-modified silicone oil, fatty acid polyethylene glycol ester, etc.

[0029] The interlacing nozzle mentioned in step (3) is located in front of or inside the twisting device. This arrangement allows the introduction of microcapsules and the twisting and binding to occur simultaneously. The microcapsules are mechanically locked the moment they are wrapped by the fiber bundle, forming a stable embedded structure. This avoids the problem that microcapsules only adhere to the surface when twisting is done first and then introduced.

[0030] In the technical solution of this invention, there is a synergistic effect among the steps: The polar groups formed on the fiber surface by the low-temperature plasma treatment in step (2) not only improve the surface wettability of the fiber, but also enhance the affinity for microcapsules, making the subsequent embedded microcapsules more firmly bonded to the fiber. The twisting process in step (3) imparts basic elasticity to the fiber while physically locking the microcapsules between the fiber monofilaments through mechanical cohesion, forming a stable embedded structure, which makes the water-washing resistance of the microcapsules significantly better than that of traditional finishing methods. The supercritical carbon dioxide fluid heat setting in step (4) utilizes its low surface tension and high diffusivity to eliminate internal stress in the fiber and stabilize the twisted structure. At the same time, it can penetrate the amorphous region of the fiber without damaging the microcapsule structure and carry environmentally friendly additives to be evenly distributed inside the fiber, thus promoting the formation and stability of the fiber's elastic structure.

[0031] Raw materials and equipment used in the examples: Polyester raw material yarn: 50D / 24f fully drawn polyester yarn (FDY).

[0032] Low-temperature plasma treatment equipment: atmospheric pressure low-temperature plasma treatment machine.

[0033] Phase change microcapsules: Paraffin microcapsules, particle size 0.5-10 micrometers, phase change temperature 30℃.

[0034] Twisting machine: R522 type double twister.

[0035] Interlacing nozzle: HL type interlacing nozzle.

[0036] Supercritical carbon dioxide treatment equipment: HA type supercritical fluid extraction / reaction device.

[0037] Environmentally friendly additives: Tributyl citrate (plasticizer), polyether-modified silicone oil (dispersant).

[0038] Test method: Elastic recovery rate: The elastic recovery rate of the fiber at 5% elongation was determined according to GB / T 14337-2008 "Test Method for Tensile Properties of Chemical Fibers Short Fibers".

[0039] Microcapsule retention rate: Take 1g of fiber sample and wash it in soap solution at 40℃ for 30 minutes (simulating one standard water wash). Repeat 20 times and measure the change in microcapsule content before and after washing to calculate the retention rate.

[0040] Temperature regulation performance: The phase transition enthalpy of the fiber was determined using differential scanning calorimetry (DSC).

[0041] Example 1

[0042] The purpose of this embodiment is to verify the comprehensive performance of polyester fibers prepared by the complete technical solution of the present invention (including low-temperature plasma treatment, twisting and embedding microcapsules, supercritical carbon dioxide heat setting and environmentally friendly additives).

[0043] The implementation steps are as follows: (1) Winding: The polyester raw yarn is wound on a winding machine. The winding speed is controlled at 500 meters / minute. By changing the yarn bobbin winding form, the raw yarn is made suitable for subsequent processing to obtain the winding bobbin.

[0044] (2) Surface modification: The wound fibers are sent into a low-temperature plasma treatment device with atmospheric pressure, using oxygen as the working gas, with the treatment power set to 200W and the treatment time to 2 minutes. During the treatment, high-energy particles bombard the fiber surface, forming micro-pits and introducing polar groups such as hydroxyl and carboxyl groups.

[0045] (3) Twisting and Microcapsule Embedding: The surface-modified fibers are twisted on a two-twist machine with a twist rate of 800 twists / meter. During the twisting process, phase change microcapsules are introduced into the fiber bundle through a cross-linking nozzle located in front of the twisting device. The air pressure of the cross-linking nozzle is controlled at 0.4 MPa. The phase change microcapsules are paraffin microcapsules with a particle size of 2-5 micrometers. Utilizing the mechanical cohesion generated by twisting, the microcapsules are physically embedded between the fiber monofilaments.

[0046] (4) Heat setting: The twisted fibers are placed in a supercritical carbon dioxide treatment device for heat setting. The treatment temperature is 120℃, the pressure is 20MPa, the treatment time is 40 minutes, and the density of supercritical carbon dioxide is 0.65 g / cm³. The supercritical carbon dioxide fluid contains 1% of its total mass of environmentally friendly additives, namely tributyl citrate. During the treatment, supercritical carbon dioxide penetrates the amorphous region of the fiber, eliminates internal stress and stabilizes the twisted structure, while carrying the environmentally friendly additives evenly distributed inside the fiber.

[0047] (5) Rewinding: The heat-set fibers are rewinded on a rewinding machine. By adjusting the tension, the filaments are made uniform and the roll size is increased to obtain high-elasticity and durable polyester fibers.

[0048] Results: Tests showed that the fiber prepared in this embodiment had an elasticity recovery rate of 96.3%, a microcapsule retention rate (after 20 washes) of 93.5%, and a phase change enthalpy of 18.6 J / g. This indicates that the fiber possesses excellent high elasticity, washability, and intelligent temperature regulation capabilities.

[0049] Example 2

[0050] The purpose of this embodiment is to examine the stability and adjustability of the method of the present invention under different process parameters.

[0051] The implementation steps are as follows: The process is basically the same as in Example 1, except that: in step (2), the working gas for the low-temperature plasma treatment is nitrogen, the treatment power is 100W, and the treatment time is 3 minutes; in step (3), the twisting degree is 1000 twists / meter, the gas pressure of the interlacing nozzle is 0.3MPa, and the microcapsule particle size is 1-3 micrometers; in step (4), the heat setting temperature is 110℃, the pressure is 25MPa, the treatment time is 50 minutes, the supercritical carbon dioxide density is 0.75 g / cm³, and the amount of environmentally friendly additive is 0.5% (still tributyl citrate).

[0052] Results: The fiber prepared in this embodiment exhibited an elastic recovery rate of 95.8%, a microcapsule retention rate of 92.1%, and a phase transition enthalpy of 17.9 J / g. These properties are similar to those of Example 1, indicating that the method of this invention has good stability within appropriate parameter ranges.

[0053] Example 3

[0054] The purpose of this embodiment is to further verify the broad adaptability of process parameters and to use different types of environmentally friendly additives.

[0055] The implementation steps are as follows: The process is basically the same as in Example 1, except that: in step (2), the working gas for the low-temperature plasma treatment is air, the treatment power is 300W, and the treatment time is 30 seconds; in step (3), the twisting degree is 600 twists / meter, the gas pressure of the interlacing nozzle is 0.6MPa, and the microcapsule particle size is 5-8 micrometers; in step (4), the heat setting temperature is 140℃, the pressure is 10MPa, the treatment time is 20 minutes, the supercritical carbon dioxide density is 0.45 g / cm³, and the environmentally friendly additive is polyether modified silicone oil, with an addition amount of 3%.

[0056] Results: The fiber prepared in this embodiment exhibited an elastic recovery rate of 94.2%, a microcapsule retention rate of 91.8%, and a phase transition enthalpy of 17.2 J / g. These results maintain a high level, demonstrating that the method of this invention has good adaptability to different parameter combinations.

[0057] Comparative Example 1 The purpose of this comparative example is to examine the effect of omitting low-temperature plasma treatment on fiber properties.

[0058] Implementation steps: basically the same as in Example 1, except that the low-temperature plasma treatment in step (2) is omitted, that is, twisting and microcapsule embedding are performed directly after winding. The remaining steps are the same as in Example 1.

[0059] Results: The fiber prepared in Comparative Example 1 exhibited an elastic recovery rate of 93.5%, a microcapsule retention rate of 82.6%, and a phase transition enthalpy of 16.5 J / g. Compared to Example 1, the microcapsule retention rate significantly decreased (from 93.5% to 82.6%), indicating that the polar groups formed by low-temperature plasma treatment enhanced the fiber's affinity for the microcapsules and improved the firmness of microcapsule embedding. Simultaneously, the elastic recovery rate decreased slightly, suggesting that surface modification had a certain optimizing effect on the fiber structure.

[0060] Comparative Example 2 The purpose of this comparative study is to investigate the effect of not adding environmentally friendly auxiliaries during supercritical carbon dioxide heat setting on fiber properties.

[0061] Implementation steps: basically the same as in Example 1, except that no environmentally friendly additives are added in step (4), and the rest of the steps are the same as in Example 1.

[0062] Results: The fiber prepared in Comparative Example 2 showed an elastic recovery rate of 92.8%, a microcapsule retention rate of 93.2%, and a phase transition enthalpy of 18.1 J / g. Compared with Example 1, the elastic recovery rate decreased from 96.3% to 92.8%, indicating that the environmentally friendly additives effectively promoted molecular chain rearrangement and improved the setting effect under the assistance of supercritical carbon dioxide; while the microcapsule retention rate and phase transition enthalpy did not change significantly, indicating that the environmentally friendly additives mainly affected the elastic structure of the fiber.

[0063] Comparative Example 3 The purpose of this comparative study is to examine the effect of using traditional steam heat setting instead of supercritical carbon dioxide heat setting on fiber properties.

[0064] Implementation steps: basically the same as in Example 1, except that the heat setting in step (4) is done by using a traditional electric steamer for steam heat setting, the processing temperature is 120°C and the processing time is 40 minutes, and supercritical carbon dioxide is not used. The remaining steps are the same as in Example 1.

[0065] Results: The fiber prepared in Comparative Example 3 exhibited an elastic recovery rate of 86.4%, a microcapsule retention rate of 76.8%, and a phase transition enthalpy of 15.3 J / g. Compared to Example 1, all properties significantly decreased: the elastic recovery rate decreased by approximately 10 percentage points, the microcapsule retention rate decreased by approximately 17 percentage points, and the phase transition enthalpy decreased by approximately 3.3 J / g. This indicates that supercritical carbon dioxide heat setting has a significant advantage in protecting the microcapsule structure and stabilizing fiber elasticity. The high temperature and moisture in steam setting may damage some microcapsules, and the setting effect is not as uniform as that of supercritical carbon dioxide.

[0066] Comparative Example 4 The purpose of this comparative example is to examine the difference in water washability between the traditional finishing method of applying microcapsules and the twisting and embedding method of the present invention.

[0067] Implementation steps: The fiber was treated according to steps (1), (2), (4) and (5) of Example 1 (i.e., without microcapsule embedding step), and then the fiber was immersed in a treatment solution containing phase change microcapsules (the microcapsule concentration was equivalent to the embedding amount in Example 1), dipped and squeezed twice, with a squeezing rate of 80%, and then dried at 80°C to obtain the comparative fiber.

[0068] Results: The fiber prepared in Comparative Example 4 exhibited an elasticity recovery rate of 94.1%, a microcapsule retention rate (after 20 washes) of 58.3%, and a phase transition enthalpy of 12.7 J / g. Compared to Example 1, the microcapsule retention rate dropped sharply from 93.5% to 58.3%, indicating that microcapsules applied using traditional finishing methods only adhere to the fiber surface, resulting in poor wash resistance. In contrast, this invention physically locks the microcapsules inside the fiber through twisting and embedding, significantly improving functional durability. The elasticity recovery rate is similar to that of Example 1, indicating that finishing has little impact on fiber elasticity, but the temperature regulation function is significantly weakened due to microcapsule loss.

[0069] Based on the results of the above embodiments and comparative examples, it can be seen that: This invention successfully prepared polyester fibers with high elasticity, durability, and intelligent temperature regulation functions through the synergistic effect of low-temperature plasma surface modification, twisting and embedding microcapsules, and supercritical carbon dioxide-assisted heat setting. Specifically, low-temperature plasma treatment enhances the embedding strength of the microcapsules; the twisting and embedding method gives the microcapsules excellent wash resistance; supercritical carbon dioxide heat setting stabilizes the fiber's elastic structure while protecting the microcapsules; and the addition of environmentally friendly additives further improves the setting effect. Compared with traditional processes, the fiber elasticity recovery rate prepared by this invention is increased by 5-10 percentage points, the microcapsule wash resistance retention rate is increased by more than 30 percentage points, the temperature regulation function is significantly enhanced in durability, and the entire process is environmentally friendly and pollution-free, showing good prospects for industrial application.

[0070] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

[0071] In conclusion, the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-elasticity, durable polyester fiber, characterized in that, Includes the following steps: (1) Winding: The polyester raw yarn is wound to make it suitable for subsequent processing by changing the yarn spool packaging. (2) Surface modification: The fibers after winding are subjected to low-temperature plasma treatment, and high-energy particles are used to bombard the fiber surface to form micro-pits and introduce polar groups. (3) Twisting and microcapsule embedding: The surface-modified fibers are twisted, and phase change microcapsules are introduced into the fiber bundle through the interlacing nozzle during the twisting process. The mechanical cohesion force generated by twisting is used to physically embed the microcapsules between the fiber monofilaments. (4) Heat setting: The twisted fiber is placed in supercritical carbon dioxide fluid for heat setting treatment. The high permeability of supercritical carbon dioxide is used to eliminate the internal stress of the fiber and stabilize the twisted structure. (5) Rewinding: The heat-set fibers are rewinded, and the tension is adjusted to make the filaments uniform and the roll size is increased to obtain high-elasticity and durable polyester fibers.

2. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, In step (1), the winding speed of the winding yarn is 400-600 meters / minute.

3. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, In step (2), the low-temperature plasma treatment uses air, oxygen or nitrogen as the working gas, with a treatment power of 50-300W and a treatment time of 30 seconds to 5 minutes.

4. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, The phase change microcapsules mentioned in step (3) have a particle size of 0.5-10 micrometers and are paraffin microcapsules.

5. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, In step (3), the twisting degree is 600-1200 twists / meter, and the air pressure of the interlacing nozzle is 0.2-0.6MPa.

6. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, In step (4), the temperature of the supercritical carbon dioxide fluid treatment is 100-140℃, the pressure is 10-30MPa, the treatment time is 20-60 minutes, and the density of the supercritical carbon dioxide fluid is 0.4-0.9 g / cm³.

7. The method for preparing a high-elasticity, durable polyester fiber as described in claim 6, characterized in that, In step (4), the supercritical carbon dioxide fluid contains environmentally friendly additives, which are non-toxic plasticizers or dispersants, and their addition amount accounts for 0.1%-5% of the total mass of the supercritical carbon dioxide fluid.

8. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, The interlacing nozzle mentioned in step (3) is located in front of the twisting device or inside the twisting device.

9. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, The low-temperature plasma treatment in step (2) forms polar groups on the fiber surface, which enhance the fiber's affinity for the microcapsules.

10. The method for preparing a high-elasticity, durable polyester fiber as described in claim 1, characterized in that, In step (4), the supercritical carbon dioxide fluid penetrates the amorphous region of the fiber during the heat setting process, while simultaneously distributing the environmentally friendly additives evenly within the fiber.

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