Super-extinction moisture-absorbing and sweat-releasing polyester DTY fiber, and preparation method and processing technology thereof
By combining modified kaolin nanotubes with a third modified monomer, the problem of performance degradation of recycled polyester DTY fiber after the addition of nano titanium dioxide was solved, achieving the excellent performance of ultra-dull moisture-wicking polyester DTY fiber, which is suitable for the field of chemical fiber fabrics.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU HENGKE ADVANCED MATERIALS CO LTD
- Filing Date
- 2024-01-10
- Publication Date
- 2026-05-19
AI Technical Summary
The crystallinity of existing recycled polyester DTY fibers is affected after adding nano titanium dioxide as a matting agent, resulting in impaired fiber properties and weakened mechanical properties during processing, making it difficult to achieve excellent matting, moisture absorption and breathability and antistatic properties.
Modified kaolin nanotubes and a third modified monomer with a specific structure are used to intercalate and modify the kaolin nanotubes to combine with PET polymers to form a tubular structure, which increases the interlayer spacing, improves the moisture absorption and air permeability of the fiber, and maintains its mechanical properties.
It achieves excellent dullness, moisture absorption and breathability of ultra-dull, moisture-wicking polyester DTY fiber, while maintaining the structural uniformity and mechanical properties of the fiber, avoiding filament breakage, and improving the application performance of the fiber.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of fiber manufacturing, specifically to an ultra-dull, moisture-wicking polyester DTY fiber and its preparation method and processing technology. Background Technology
[0002] Polyethylene terephthalate (PET) is widely used in various fields such as fibers, packaging materials, and engineering plastics due to its excellent physicochemical properties, including high strength, high modulus, heat resistance, dimensional stability, and chemical stability. However, with the increasing demand for PET, petroleum resources are becoming increasingly scarce, and PET pollution is also increasing. Therefore, the research and development of recycled polyester fibers (polyester) is of great environmental significance.
[0003] The production methods of recycled polyester are mainly divided into two types: physical methods and chemical methods. Physically recycled polyester refers to fibers obtained by melt spinning after collecting, classifying, washing, crushing, purifying, and drying waste polyester. Another type, physicochemically recycled polyester, involves melting waste polyester, then thickening it in a liquid or solid phase before spinning. This method primarily uses physical methods, supplemented by chemical methods to adjust the relative molecular mass. It represents an improvement and upgrade of the physical method, differing from virgin polyester in that it involves at least one additional melt processing step. Chemically recycled polyester, on the other hand, involves depolymerizing waste polyester (through hydrolysis, alcoholysis, supercritical fluid degradation, etc.) into monomers, followed by refining, polymerization, and spinning. This method differs from virgin polyester in that it involves at least one additional high-temperature depolymerization and refining process.
[0004] Due to the wide availability of raw materials and complex recycling processes, recycled polyester DTY fibers inevitably exhibit some differences in structure and properties compared to virgin polyester. The structure and properties of the fibers determine their potential for textile processing and product development. In recent years, numerous scholars have conducted research on recycled polyester. Zhou Faming et al. (Zhou Faming, Yang Zhongkai, Tang Shijun, et al. Study on the structure and properties of recycled polyester and its fibers [J]. Synthetic Fiber Industry, 2014, 37(1):13-16) studied the structure and properties of recycled polyester chips and their fibers; Lu Tingting et al. (Lu Tingting, Yin Yanhua, Zhang Ruiyun, et al. Study on the processability of recycled polyester DTY fibers [J]. Synthetic Fiber Industry, 2019, 42(2):21) studied the processability of recycled polyester DTY fibers. Numerous studies have demonstrated that during processing, whether it is temperature treatment or chemical treatment, the mechanical properties of virgin polyester DTY fibers will be weakened. Meanwhile, to enhance the performance of polyester DTY fibers, such as matting, low-temperature dyeing, moisture absorption and breathability, and antistatic properties, physical additives are often added during the processing of polyester DTY fibers. For example, in the field of matting fibers, a common technique is to add nano-titanium dioxide as a matting agent during the preparation of the fiber raw materials. However, the presence of nano-titanium dioxide will more or less affect the crystallinity of polyester DTY fibers, thereby impairing other properties of the fiber. Summary of the Invention
[0005] To address the problems existing in the prior art, this invention provides an ultra-dull, moisture-wicking polyester DTY fiber, its preparation method, and processing technology.
[0006] A super-dull, moisture-wicking polyester DTY fiber, by weight, comprises the following components: 80-120 parts terephthalic acid, 75-95 parts ethylene glycol, 5-20 parts a third modified monomer, and 1-5 parts modified kaolin nanotubes; wherein the structure of the third modified monomer is shown in Formula I:
[0007]
[0008] In some embodiments of the present invention, the method for preparing the modified kaolin nanotubes includes the following steps:
[0009] S1: Wash and dry the flaky kaolin, grind it to a particle size of less than 100 μm, place it in a mixed solution of deionized water and organic solvent, stir at 50-80℃ for 12-15 h, filter and separate, and dry.
[0010] S2: Disperse the kaolin complex impregnated with organic solvent molecules in a container containing a polar small molecule compound, sonicate for 3-4 hours, and centrifuge to obtain a wet sample of kaolin-polar small molecule complex.
[0011] S3: Disperse the kaolin-polar small molecule wet sample obtained in S2 in a mixed solution of the modifier and the polar small molecule compound with the structure shown in Formula II, stir vigorously for 12-15 h, transfer to a reaction vessel, and react in a sealed container for 10-16 h;
[0012]
[0013] S4: After the reaction in S3 is completed, the system is cooled to room temperature, filtered and separated, washed and dried to obtain the modified kaolin nanotubes.
[0014] In some embodiments of the present invention, when preparing the modified kaolin nanotubes, the organic solvent in S1 is at least one of dimethyl sulfoxide, glycerol, and propylene glycol.
[0015] In some embodiments of the present invention, when preparing the modified kaolin nanotubes, the polar small molecule compound in S2 is at least one of methanol, ethanol, propanol and 1,3-butanediol.
[0016] In some embodiments of the present invention, when preparing the modified kaolin nanotubes, the amount of modifier used in S3 is 10-20% of the amount of the kaolin-polar small molecule composite used. This is because the inventors have experimentally verified that too little modifier cannot effectively disrupt the interlayer cohesion of kaolin, resulting in a low yield of tubular kaolin; while too much modifier can easily over-enhance the hydrogen bonds of the modified kaolin nanotubes, leading to a larger length and diameter of the modified kaolin nanotubes and poor uniformity in product size.
[0017] To better integrate kaolin into PET polymer molecules, the inventors considered intercalation modification of flake kaolin. In this invention, flake kaolin is used as the main material. First, precursors (dimethyl sulfoxide, glycerol, propylene glycol) are inserted into its interlayer spaces to weaken hydrogen bonding and increase interlayer distance, making its structure insufficient to overcome geometric stress and thus causing bending deformation, resulting in tubular kaolin. Then, highly polar small organic molecules are inserted into the kaolin interlayer spaces through ultrasonic dispersion. Finally, high-temperature heating allows molecules with slightly larger steric hindrance to enter the kaolin interlayer spaces by replacing the polar small molecules.
[0018] The modifier with Formula II can interact with the interlayer hydroxyl groups of kaolinite through hydroxyl groups, forming strong hydrogen bonds. Furthermore, the modifier dispersed at the edges of the modified kaolinite layers can also form intermolecular forces with the PET polymer used to prepare the ultra-dull, moisture-wicking polyester DTY fiber through hydroxyl groups. Ultimately, this allows the modified kaolinite nanotubes to be well integrated into the PET polymer system. More importantly, the formation of tubular kaolinite significantly reduces interparticle aggregation, thereby promoting the uniform dispersion of the modified kaolinite nanotubes in the PET polymer and achieving ultra-dull fiber properties.
[0019] A method for preparing the super-dull, moisture-wicking polyester DTY fiber includes the following steps: SS1: Terephthalic acid, ethylene glycol and the third modified monomer are added to a reaction vessel, along with a catalyst and a heat stabilizer. After thorough stirring, an inert gas is introduced, and the temperature and pressure are adjusted to initiate the esterification reaction. After the reaction is completed, the temperature is raised again and a vacuum is drawn to initiate the polycondensation reaction. At this time, the modified kaolin nanotubes are added to the system.
[0020] SS2: After the reaction is complete, the obtained modified PET polymer is introduced into the spinning box through the melt conveying pipe, and then spun out at the spinneret through the metering pump system. After ring blowing, bundling and oiling, and stretching, the super dull moisture-wicking polyester DTY fiber is obtained.
[0021] In some embodiments of the present invention, when preparing the ultra-dull, moisture-wicking polyester DTY fiber, the esterification reaction conditions in SS1 are 100-180°C and 150-200 Pa. The catalyst can be antimony trioxide, antimony acetate, or antimony glycolate, etc., and the heat stabilizer can be trimethyl phosphate (TMP), dimethyl phosphate (DMP), diphenyl phosphate, or triphenyl phosphate (TPP), etc.
[0022] In some embodiments of the present invention, when preparing the super-dull, moisture-wicking polyester DTY fiber, the amount of the third modified monomer added is 10-15 parts.
[0023] In some embodiments of the present invention, when preparing the ultra-dull, moisture-wicking polyester DTY fiber, the conditions for the polycondensation reaction in SS1 are 200-250°C and 180-280 Pa.
[0024] Although modifying the ultra-dull, moisture-wicking polyester DTY fiber with the third modifying monomer having the structure of Formula I can reduce the regularity of the PET polymer molecular chain, thereby reducing its enthalpy of fusion and improving the moisture absorption and impact resistance of the ultra-dull, moisture-wicking polyester DTY fiber, the tensile strength of the resulting ultra-dull, moisture-wicking polyester DTY fiber decreases significantly with increasing dosage of the third modifying monomer, making it prone to breakage during spinning. Therefore, preferably, the dosage of the third modifying monomer is 10-15 parts.
[0025] When modified kaolin nanotubes are added to the ultra-dull, moisture-wicking polyester DTY fiber, the tubular physical structure of the modified kaolin nanotubes easily forms countless tiny nanoscale pores within the fiber structure. Combined with the increased interlayer spacing within the modified kaolin nanotubes, the breathability and moisture-wicking performance of the ultra-dull, moisture-wicking polyester DTY fiber is significantly increased compared to unmodified polyester DTY fiber. However, the amount of modified kaolin nanotubes added must be controlled within an appropriate range. If the modified kaolin nanotubes are excessive, the modified EPT polymer will become brittle and difficult to spin into fibers.
[0026] In some embodiments of the present invention, the cross-section of the individual fibers contained in the ultra-dull moisture-wicking polyester DTY fiber is X-shaped, which can enhance the formation of capillary action in the fiber and facilitate the moisture absorption and wicking of the fabric.
[0027] Beneficial effects: Compared with the prior art, the present invention provides an ultra-dull, moisture-wicking polyester DTY fiber:
[0028] 1. By intercalating and modifying sheet-like kaolin, polar molecules containing hydroxyl and amino groups are introduced between the kaolin layers, increasing the interlayer spacing of the sheet-like kaolin. The resulting modified kaolin nanotubes have a certain spatial structure, which helps the ultra-dull, moisture-wicking polyester DTY fiber achieve excellent dullness. Moreover, the modified kaolin nanotubes have good affinity with PET polymers and are not prone to aggregation, resulting in a uniform structure of the final ultra-dull, moisture-wicking polyester DTY fiber.
[0029] 2. A PET polymer for the ultra-dull, moisture-wicking polyester DTY fiber is prepared by using a hydroxy acid ester with a specific structure as the third modifying monomer, thereby improving the moisture-wicking properties of the PET polymer while maintaining its mechanical properties.
[0030] 3. By adjusting the amount of the third modified monomer and the modified kaolin nanotubes added, the cross-section of the ultra-dull moisture-wicking polyester DTY fiber is spun into an X-shaped surface without damaging the crystallinity of the PET polymer, thereby obtaining an ultra-dull moisture-wicking polyester DTY fiber that is not easy to break, has good elasticity, and excellent moisture-wicking performance. Detailed Implementation
[0031] The present invention will be further described in detail below with reference to embodiments. It should be noted that the following embodiments and comparative examples are examples of the present invention and are only used to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from the spirit or scope of the invention.
[0032] The following examples illustrate the preparation of modified kaolin nanotubes used in the embodiments and comparative examples:
[0033] Modified kaolin nanotubes-1
[0034] S1: 100g of flake kaolin purchased from Qianhai Jishengya (Shenzhen) Technology Co., Ltd. was washed, dried, and ground until the particle size was below 100μm. It was then placed in a mixed solution of deionized water and dimethyl sulfoxide, stirred at 50℃ for 12h, filtered and separated, and dried.
[0035] S2: Disperse the kaolin complex impregnated with dimethyl sulfoxide in a container containing methanol, sonicate for 3 hours, and centrifuge to obtain a wet sample of kaolin-methanol.
[0036] S3: Disperse 50g of the kaolin-methanol wet sample obtained from S2 in a mixed solution containing 5g of the modifier with the structure shown in Formula II and 200ml of methanol. After stirring vigorously for 12h, transfer the mixture to a reaction vessel and react in a sealed container for 10h.
[0037]
[0038] S4: After the S3 reaction is completed, the system is cooled to room temperature, filtered and separated, washed and dried to obtain the modified kaolin nanotube-1.
[0039] Modified kaolin nanotubes-2
[0040] S1: 100g of flake kaolin purchased from Qianhai Jishengya (Shenzhen) Technology Co., Ltd. was washed, dried, and ground until the particle size was below 80μm. It was then placed in a mixed solution of deionized water and glycerol, stirred at 70℃ for 12h, filtered and separated, and dried.
[0041] S2: Disperse the kaolin complex impregnated with glycerol in a container containing ethanol, sonicate for 4 hours, and centrifuge to obtain a wet sample of kaolin-ethanol.
[0042] S3: Disperse 50g of the kaolin-ethanol wet sample obtained from S2 in a mixed solution of 7.5g of the modifier with the structure shown in Formula II and 300ml of ethanol. After stirring vigorously for 15h, transfer the mixture to a reaction vessel and react in a sealed container for 13h.
[0043]
[0044] S4: After the reaction in S3 is completed, the system is cooled to room temperature, filtered and separated, washed and dried to obtain the modified kaolin nanotubes-2.
[0045] Modified Kaolin Nanotubes-3
[0046] S1: 100g of flake kaolin purchased from Qianhai Jishengya (Shenzhen) Technology Co., Ltd. was washed, dried, and ground until the particle size was below 80μm. It was then placed in a mixed solution of deionized water and glycerol, stirred at 80℃ for 15h, filtered and separated, and dried.
[0047] S2: Disperse the kaolin complex impregnated with glycerol in a container containing propanol, sonicate for 4 hours, and centrifuge to obtain a wet sample of kaolin-propanol.
[0048] S3: Disperse 50g of the kaolin-propanol wet sample obtained from S2 in a mixed solution of 10g of the modifier with the structure shown in Formula II and 300ml of propanol. After stirring vigorously for 15h, transfer the mixture to a reaction vessel and react in a sealed container for 16h.
[0049]
[0050] S4: After the reaction in S3 is completed, the system is cooled to room temperature, filtered and separated, washed and dried to obtain the modified kaolin nanotubes-3.
[0051] Modified Kaolin Nanotubes-4
[0052] The preparation process is the same as that of modified kaolin nanotube-1, except that the amount of the modifier with the structure shown in Formula II added is 4g.
[0053] Modified Kaolin Nanotubes-5
[0054] The preparation process is the same as that of modified kaolin nanotubes-3, except that the amount of modifier with the structure shown in Formula II added is 11g.
[0055] Example 1
[0056] SS1: Add 80 parts of terephthalic acid, 75 parts of ethylene glycol and 5 parts of the third modified monomer to a reactor, along with 3.2 parts of antimony trioxide and 5 parts of TMP. After thorough stirring, purge with nitrogen, adjust the temperature to 100℃ and the pressure to 150Pa, and begin the esterification reaction. The reaction lasts for 10 hours. After the reaction is complete, raise the temperature again and evacuate to 200℃ and 180Pa to begin the polycondensation reaction. At this time, add 1 part of the modified kaolin nanotube-1 to the system.
[0057] SS2: After the reaction is complete, the obtained modified PET polymer is introduced into the spinning box through the melt conveying pipe, and then spun out at the spinneret through the metering pump system. After passing through the ring blower, bundling and oiling, and stretching, the super dull moisture-wicking polyester DTY fiber is obtained. The ring blower has a wind speed of 2.5 m / s, a network pressure of 0.40 MPa, a first hot roller stretching speed of 2500 m / min and a temperature of 83℃; a second hot roller stretching speed of 4000 m / min and a temperature of 126℃; and a winding speed of 3950 m / min.
[0058] Example 2
[0059] Consistent with Example 1, except that the amount of the third modified monomer used is [missing information]. 10 copies Correspondingly, the amount of antimony trioxide catalyst used is 3.3 parts.
[0060] Example 3
[0061] Consistent with Example 1, except that the amount of the third modified monomer used is [missing information]. 15 copies Correspondingly, the amount of antimony trioxide catalyst used is 3.4 parts.
[0062] Example 4
[0063] Consistent with Example 1, except that the amount of the third modified monomer used is [missing information]. 20 copies Correspondingly, the amount of antimony trioxide catalyst used is 3.5 parts.
[0064] Example 5
[0065] Similar to Example 4, except that in SS1, the raw materials used are 100 parts terephthalic acid, 80 parts ethylene glycol, 20 parts third modified monomer and 3 parts modified kaolin nanotube-2; the amount of catalyst is adjusted according to 2 wt% of the total mass of the raw materials.
[0066] Example 6
[0067] Similar to Example 4, except that in SS1, the raw materials used are 120 parts terephthalic acid, 95 parts ethylene glycol, 20 parts third modified monomer and 5 parts modified kaolin nanotube-3; the amount of catalyst is adjusted according to 2 wt% of the total mass of the raw materials.
[0068] Example 7
[0069] Similar to Example 6, except that the modified kaolin nanotubes used are modified kaolin nanotubes-4.
[0070] Example 8
[0071] Similar to Example 6, except that the modified kaolin nanotubes used are modified kaolin nanotubes-5.
[0072] Comparative Example 1
[0073] Similar to Example 1, except that the third modified monomer was not added when preparing the PET polymer.
[0074] Comparative Example 2
[0075] Same as Example 1, except that the modified kaolin nanotubes are not added.
[0076] Comparative Example 3
[0077] Similar to Example 1, except that the third modified monomer and modified kaolin nanotubes are not added.
[0078] Comparative Example 4
[0079] Similar to Example 6, except that the amount of modified kaolin nanotubes-3 added is 6 parts.
[0080] Performance testing
[0081] Gloss: The gloss of the above-mentioned ultra-dull moisture-wicking polyester DTY fiber was tested using 60° incident light;
[0082] Moisture wicking properties: The water absorption rate (%) and drying rate (g / h) of the ultra-dull moisture wicking polyester DTY fiber were tested in accordance with the national standard GB / T 21655.1-2023.
[0083] Elastic modulus: The elastic modulus of super dull moisture-wicking polyester DTY fiber obtained by testing according to the national standard GB / T 32376-2015.
[0084] The test results of the fibers obtained in Examples 1-8 and Comparative Examples 1-4 are detailed in Table 1:
[0085] Table 1. Performance test results of the fibers obtained in Examples 1-8 and Comparative Examples 1-4
[0086] Gloss (%) Water absorption rate (%) Drying rate (g / h) Elastic modulus (GPa) Example 1 30 162 0.41 1.5 Example 2 31 175 0.39 1.5 Example 3 31 184 0.36 1.6 Example 4 32 180 0.32 1.4 Example 5 28 201 0.35 1.8 Example 6 27 216 0.42 1.9 Example 7 29 205 0.34 1.6 Example 8 28 228 0.43 1.5 Comparative Example 1 35 147 0.32 1.3 Comparative Example 2 45 158 0.22 1.4 Comparative Example 3 57 113 0.10 1.2 Comparative Example 4 25 168 0.42 1.0
[0087] The performance test results in Table 1 show that both the modified third monomer and the modified kaolin nanotubes have a significant impact on the performance of the ultra-dull, moisture-wicking polyester DTY fiber. In Examples 1-4, the water absorption rate and elastic modulus of the fibers obtained when the amount of the third modified monomer was 10 parts (Example 2) and 15 parts (Example 3) were better than those obtained when the amount of the third modified monomer was 5 parts and 20 parts. The results in Examples 7-8 show that too much or too little intercalation modifier used in the modified kaolin nanotubes can affect the gloss, water absorption rate, drying rate, and elastic modulus of the ultra-dull, moisture-wicking polyester DTY fiber. This may be because the intercalation modifier affects the molecular forces of the modified kaolin nanotubes, thereby affecting the overall structure of the fiber.
[0088] The results of Comparative Examples 1-3 show that the third modified monomer and the modified kaolin are indispensable for the super-dull, moisture-wicking polyester DTY fiber to achieve the above-mentioned excellent properties. The results of Comparative Example 4 show that excessive use of the modified kaolin nanotubes will lead to a significant reduction in the elastic modulus of the super-dull, moisture-wicking polyester DTY fiber.
[0089] In summary, the ultra-dull, moisture-wicking polyester DTY fiber prepared by the preparation method provided by this invention has excellent properties such as being less prone to breakage, having good elasticity, and good moisture-wicking properties, and has broad application prospects in the field of chemical fiber fabrics.
Claims
1. A super-dull, moisture-wicking polyester DTY fiber, characterized in that, Based on parts by weight, it comprises the following raw materials: 80-120 parts terephthalic acid, 75-95 parts ethylene glycol, 5-20 parts third modifying monomer, and 1-5 parts modified kaolin nanotubes; wherein, the structure of the third modifying monomer is shown in Formula I: ； The method for preparing the modified kaolin nanotubes includes the following steps: S1: Wash and dry the flaky kaolin, grind it to a particle size of less than 100 μm, place it in a mixed solution of deionized water and organic solvent, stir at 50-80℃ for 12-15 h, filter and separate, and dry. S2: Disperse the kaolin complex impregnated with organic solvent molecules in a container containing a polar small molecule compound, sonicate for 3-4 hours, and centrifuge to obtain a wet sample of kaolin-polar small molecule complex, wherein the polar small molecule compound is at least one of methanol, ethanol, propanol and 1,3-butanediol. S3: Disperse the kaolin-polar small molecule wet sample obtained in S2 in a mixed solution of the modifier and the polar small molecule compound with the structure shown in Formula II, stir vigorously for 12-15 h, transfer to a reaction vessel, and react in a sealed container for 10-16 h; Formula II S4: After the reaction in S3 is completed, the system is cooled to room temperature, filtered and separated, washed and dried to obtain the modified kaolin nanotubes.
2. The ultra-dull, moisture-wicking polyester DTY fiber according to claim 1, characterized in that, When preparing the modified kaolin nanotubes, the organic solvent in S1 is at least one of dimethyl sulfoxide, glycerol, and propylene glycol.
3. The ultra-dull, moisture-wicking polyester DTY fiber according to claim 1, characterized in that, When preparing the modified kaolin nanotubes, the amount of the modifier used in S3 is 10-20% of the mass percentage of the kaolin polar small molecule complex used.
4. The method for preparing the ultra-dull, moisture-wicking polyester DTY fiber according to any one of claims 1-3, characterized in that, It includes the following steps: SS1: Terephthalic acid, ethylene glycol and the third modified monomer are added to the reactor, along with a catalyst and a heat stabilizer. After thorough stirring, an inert gas is introduced, and the temperature and pressure are adjusted to begin the esterification reaction. After the reaction is completed, the temperature is raised again and a vacuum is drawn to begin the polycondensation reaction. At this time, the modified kaolin nanotubes are added to the system. SS2: After the reaction is complete, the obtained modified PET polymer is introduced into the spinning box through the melt conveying pipe, and then spun out at the spinneret through the metering pump system. After ring blowing, bundling and oiling, and stretching, the super dull moisture-wicking polyester DTY fiber is obtained.
5. The method for preparing ultra-dull, moisture-wicking polyester DTY fiber according to claim 4, characterized in that, In SS1, the amount of the third modified monomer added is 10-15 parts.
6. The method for preparing ultra-dull, moisture-wicking polyester DTY fiber according to claim 4, characterized in that, In SS1, the esterification reaction conditions are 100-180℃ and 150-200Pa.
7. The method for preparing ultra-dull, moisture-wicking polyester DTY fiber according to claim 4, characterized in that, In SS1, the conditions for the polycondensation reaction are 200-250℃ and 180-280Pa.
8. The method for preparing ultra-dull, moisture-wicking polyester DTY fiber according to claim 4, characterized in that, After spinning, the cross-section of a single fiber is X-shaped.