Preparation method of hidden sweat cotton-like polyester fabric

Abstract

The invention provides a preparation method of a hidden sweat cotton-like polyester fabric, which comprises the following steps: S10: mixing polyester, hyperbranched styrene, maleic anhydride, nano TiO2 and an initiator, preserving heat at 88-92 DEG C, and extruding and granulating to obtain extinction master batch; s20, mixing the master batch and polyester according to a ratio of 1: (3-5) to obtain a core layer, taking pure polyester as a skin layer, and performing skin-core composite extrusion and deformation to obtain the extinction hidden sweat fiber; s30, carrying out parallel composite extrusion on the high-viscosity PTT slices and the low-viscosity PTT slices to prepare flexible double-component cotton-like yarns; s40, controlling the tension of the extinction fibers to be 5.5-6.5 cN and the tension of the imitation cotton yarns to be 3.5-4.5 cN, and twisting and doubling to obtain composite yarns; s50, the composite yarn is used for preparing the fabric. The hidden sweat cotton-like polyester fabric prepared by the preparation method has both hidden sweat covering effect and high-quality cotton-like fluffy hand feeling.

Description

Technical Field

[0001] This invention relates to the field of moisture-wicking polyester fabric technology, specifically to a method for preparing a moisture-wicking cotton-like polyester fabric. Background Technology

[0002] Cotton-like polyester fabrics are widely used in the market because they combine the durability and quick-drying properties of polyester fibers with the soft feel of natural cotton fibers. However, in summer or during high-intensity sports activities, light-colored fabrics become more translucent after absorbing moisture, easily revealing dark sweat stains or showing through the skin, which can be inconvenient for wearers in social situations. Current technology typically uses a high content (usually greater than 2%-3% by weight) of titanium dioxide (TiO2) matting agent in polyester fibers to reduce light transmittance through the light scattering effect of inorganic particles. To achieve a cotton-like appearance, polyethylene terephthalate (PET) and polypropylene terephthalate (PTT) are often used in parallel composite spinning. The difference in shrinkage between the two components creates a spiral crimp, providing a fluffy feel and a cotton-like texture. However, when the two technologies mentioned above are simply combined to prepare fabrics that combine the functions of moisture absorption and cotton imitation, there are problems such as the difficulty in dispersing high-content matting agents, resulting in a rough hand feel, and the destruction of the cotton imitation effect due to the filling of inorganic particles, which damages the crimped structure of the two-component fibers. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects or problems in the prior art and provide a method for preparing a sweat-wicking imitation cotton polyester fabric. The sweat-wicking imitation cotton polyester fabric prepared by this method can take into account both the sweat-wicking effect and the high-quality cotton-like fluffy feel.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: Technical Solution 1: A method for preparing a moisture-wicking, cotton-like polyester fabric, comprising the following steps: S10: mixing polyester chips, hyperbranched styrene, maleic anhydride, nano-titanium dioxide, and an initiator, heating the mixture to 88-92℃ by stirring and maintaining the temperature, followed by melt extrusion and granulation to obtain matte polyester functional masterbatch; S20: mixing the matte polyester functional masterbatch with polyester chips at a weight ratio of 1:3-5 as the core layer raw material, and using polyester chips without titanium dioxide as the sheath layer raw material, melting them separately, then combining them for core-sheath composite extrusion, cooling and blowing, stretching, and false twisting deformation to obtain matte moisture-wicking polyester fiber; S30: selecting an intrinsic viscosity of 1.20-1.30 dL / High-viscosity polyethylene terephthalate (PET) chips and low-viscosity PET chips with an intrinsic viscosity of 0.85-0.95 dL / g are melted separately, then combined and subjected to parallel composite extrusion, cooling and blowing, stretching and winding to obtain a flexible bicomponent cotton-like yarn; S40: The matte, sweat-wicking polyester fiber and the flexible bicomponent cotton-like yarn are simultaneously fed in and twisted, wherein the feeding tension of the matte, sweat-wicking polyester fiber is controlled at 5.5-6.5 cN and the feeding tension of the flexible bicomponent cotton-like yarn is controlled at 3.5-4.5 cN to obtain a sweat-wicking cotton-like composite yarn; S50: The sweat-wicking cotton-like polyester fabric is made from the sweat-wicking cotton-like composite yarn.

[0005] Technical Solution 2 based on Technical Solution 1: The weight parts of each raw material in S10 are as follows: 70-78 parts polyester chips, 2-4 parts hyperbranched styrene, 1-3 parts maleic anhydride, 18-22 parts nano titanium dioxide, 0.05-0.15 parts initiator, 0.1-0.3 parts antioxidant, and 0.3-0.5 parts butyl stearate.

[0006] Technical Solution 3 based on Technical Solution 1: In S10, the heat preservation time is 25-35 minutes; the temperature of each temperature zone during melt extrusion is set in the range of 260-280℃, and the screw speed is set to 180-220 rpm.

[0007] Technical Solution 4 based on Technical Solution 1: In S20, the weight ratio of the skin layer to the core layer in the skin-core composite extrusion is set to 1:0.8-1.2; the melting temperature of the core layer raw material is set to 275-285℃, and the melting temperature of the skin layer raw material is set to 280-290℃.

[0008] In technical solution five based on technical solution one: S20, the wind speed of the cooling air is controlled within the range of 0.6-1.0m / s, and the wind temperature is controlled within the range of 23-27℃.

[0009] In technical solution six based on technical solution one: S20, the process parameters for stretching and false twisting deformation are: the temperature of the first hot roller is 80-90℃, the temperature of the second hot roller is 105-115℃, the stretching ratio is set to 1.8-2.2, and the false twisting speed is set to 9000-11000 rpm.

[0010] In S30, the weight ratio of the two components in the parallel composite extrusion is set to 1:0.9-1.1; the melting temperature of the high-viscosity chips is set to 250-260℃, and the melting temperature of the low-viscosity chips is set to 240-250℃.

[0011] In technical solution eight based on technical solution one: S30, the cooling air velocity is 0.4-0.6 m / s and the air temperature is 21-25℃; the process parameters for stretching and winding are: the temperature of the first hot roller is 75-85℃, the temperature of the second hot roller is 95-105℃, the stretching ratio is set to 1.4-1.6, and the winding speed is set to 3400-3600 m / min.

[0012] In technical solution nine based on technical solution one: S40, the feeding weight ratio of the matte, sweat-absorbing polyester fiber to the flexible bicomponent imitation cotton yarn is 1:0.9-1.1; the twist is set to 400-500 twists / meter.

[0013] In technical solution ten based on technical solution one: S50, the sweat-wicking imitation cotton composite yarn is knitted, dyed, and hydrophilic finished to obtain the sweat-wicking imitation cotton polyester fabric; the linear density of the matte sweat-wicking polyester fiber and the flexible bicomponent imitation cotton yarn used in the knitting is both 45-55 dtex; the dyeing temperature is controlled within the range of 110-120℃, and the setting temperature of the hydrophilic softening finish is controlled within the range of 145-155℃. As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects: To achieve the sweat-wicking function of fabrics, high concentrations of matting agents are typically added to the fibers. Half of these matting agents are titanium dioxide, and the amount added usually needs to be quite high. Current technologies often use physical blending or the addition of low-molecular-weight dispersants such as stearic acid to treat inorganic fillers. However, these dispersants are prone to thermal degradation or desorption from the particle surface during high-temperature melt spinning, leading to agglomeration of nano-titanium dioxide. These agglomerates not only clog the spinneret orifices but also cause drastic fluctuations in melt shear viscosity, resulting in a significant difference in the rheological properties of the highly filled core layer melt compared to the skin layer, making stable coating impossible.

[0014] The first technical solution of this invention introduces a solid-phase in-situ graft polymerization process of styrene and maleic anhydride during the raw material mixing stage. Utilizing the in-situ polymerization reaction initiated by frictional heating, a heat-resistant polymer coating layer compatible with the polyester matrix is ​​constructed on the surface of titanium dioxide. This coating layer acts as a molecular lubricant in the molten state, effectively reducing the shear viscosity of the highly filled core melt and matching its rheological behavior with that of the pure polyester sheath, thus achieving stable molding of high-concentration matting masterbatch in core-sheath composite spinning. However, in conventional single-component spinning, a large amount of hard particles with high filling content are still exposed on the fiber surface, leading to an increased coefficient of friction and wear on equipment during processing. This solution utilizes a core-sheath composite structure to physically isolate the particles, sealing high-concentration titanium dioxide within the fiber core. This allows the titanium dioxide to block light, while pure polyester without particles can be used as the sheath, utilizing the physical thickness of the sheath to cover the internal hard particles, thereby maintaining optical shielding while ensuring low friction on the fiber surface. Furthermore, the addition of rigid inorganic particles hinders the orientation and crystallization of polymer molecular chains, leading to a significant reduction in the thermal shrinkage difference of the bicomponent fibers. This prevents the fibers from forming the expected three-dimensional helical crimp, resulting in the failure of the cotton-like effect. This solution first prepares parallel bicomponent yarns as a skeleton to ensure that their crystallization kinetics are not disturbed, maintaining maximum crimp recovery force. Then, matte and sweat-wicking polyester fibers are twisted with these bicomponent yarns, allowing the matte function to function as an independent fiber without affecting the normal crimp of the bicomponent yarn. This avoids interference from inorganic particles on the fiber's microcrystalline structure, achieving a coexistence of the cotton-like effect and the sweat-wicking effect. By controlling the matte, sweat-wicking polyester fibers to a high tension state and the bicomponent yarn to a low tension state, the relaxed cotton-like bicomponent yarn during yarn spinning naturally floats on the outer layer, tightly wrapping the inner matte, sweat-wicking polyester fibers. This utilizes the outer layer of hydrophobic and fluffy cotton-like yarn to isolate the skin from the moist inner layer, improving the fabric's dry feel and fluffiness. Simultaneously, the capillary effect of the inner polyester fibers quickly wicks sweat away from the skin. Furthermore, the physical coating of the outer layer further blocks the path of light penetrating the moist yarn, forming a double barrier with the light-scattering function of the inner layer, significantly enhancing the fabric's anti-see-through effect when moisture-absorbing.

[0015] In technical solution two, the weight ratio of polyester chips, styrene, maleic anhydride and nano titanium dioxide is limited to ensure that sufficient monomers are provided to achieve complete coating of high specific surface area nanoparticles, preventing local agglomeration caused by incomplete coating, and also avoiding self-polymerization and cross-linking reaction caused by excessive monomers, thus preventing excessive decrease in the melt index of the masterbatch.

[0016] In technical solution three, a specific mixing and holding time and extrusion temperature are used, allowing the monomer to be adsorbed and reacted at the interface through diffusion while the polyester chips are not molten, forming a stable chemical bond rather than physical adsorption. Combined with a segmented temperature-controlled extrusion process, this ensures that the grafted product is fully homogenized during the melt plasticization process, avoiding damage to the grafted layer due to localized overheating, thereby producing a functional masterbatch with uniform dispersion and high thermal stability.

[0017] In technical solution four, by diluting the functional masterbatch in a specific ratio, the final titanium dioxide concentration in the core layer is maintained at a high level that can effectively block the penetration of visible light, while avoiding fluid breakage caused by excessive filler concentration.

[0018] In technical solution five, high-flow-rate cooling air and specific air temperature control accelerate the curing and molding of high-filled fibers with large heat capacity, preventing secondary agglomeration of inorganic particles during slow cooling.

[0019] In technical solution six, a lower draw ratio and a specific hot roller temperature combination are used to avoid skin layer rupture or core layer voiding caused by excessive draw. Combined with false twist, the fiber produces appropriate crimp and bulkiness without damaging the integrity of the skin layer, thus preserving the soft touch of the fiber.

[0020] In technical solution seven, by setting independent melting temperatures for the high-viscosity and low-viscosity components, fine-tuning and matching of the melt viscosity of the two components is achieved at the spinneret exit, preventing melt bending or peeling caused by excessive viscosity differences. The set cooling conditions control the crystallization rate, allowing sufficient internal stress difference to accumulate between the two components during the solidification process, ensuring the formation of a spiral coil structure.

[0021] In technical solution eight, a specific low-temperature stretching and high-speed winding process helps to improve the crystal structure of polypropylene terephthalate, while avoiding the loss of molecular chain elasticity caused by excessive heat setting at high temperatures.

[0022] In technical solution nine, the tightness and stability of the yarn structure are ensured by controlling the feeding weight ratio and twist of the two yarns.

[0023] In technical solution ten, fine denier fibers are selected and woven on a circular knitting machine, which improves the fabric density and further reduces the linear transmittance of light. Controlling the dyeing temperature below the elastic damage threshold of polypropylene terephthalate prevents the relaxation and degradation of the spiral crimp structure caused by high temperatures. Combined with a high-temperature setting hydrophilic finishing process, durable water-conducting channels are built on the fabric surface, ensuring that the finished fabric maintains excellent elastic recovery and quick-drying properties while possessing a cotton-like appearance. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other 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.

[0025] This invention relates to a method for preparing a sweat-wicking, cotton-like polyester fabric, which mainly includes the following steps: S10: Polyester chips, hyperbranched styrene, maleic anhydride, nano titanium dioxide and initiator are mixed, heated to 88-92℃ by stirring and kept at that temperature, and then melt extruded and granulated to obtain matte polyester functional masterbatch. S20: The matte polyester functional masterbatch and polyester chips are mixed at a weight ratio of 1:3-5 as the core layer material, and the polyester chips without titanium dioxide are used as the sheath material. They are melted separately, and then combined for sheath-core composite extrusion, cooling and blowing, stretching and false twisting deformation to obtain matte sweat-proof polyester fiber. S30: Select high-viscosity polyethylene terephthalate (PET) chips with an intrinsic viscosity of 1.20-1.30 dL / g and low-viscosity PET chips with an intrinsic viscosity of 0.85-0.95 dL / g, melt them separately, and then combine them for parallel composite extrusion, cooling and blowing, stretching and winding to obtain flexible bicomponent cotton-like yarn; S40: The matte, sweat-wicking polyester fiber and the flexible bicomponent cotton-like yarn are fed in simultaneously and twisted, wherein the feeding tension of the matte, sweat-wicking polyester fiber is controlled to be 5.5-6.5 cN and the feeding tension of the flexible bicomponent cotton-like yarn is controlled to be 3.5-4.5 cN, to obtain a sweat-wicking cotton-like composite yarn. S50: The sweat-wicking imitation cotton composite yarn is used as raw material to make the sweat-wicking imitation cotton polyester fabric.

[0026] The following will explain each of the above steps in detail.

[0027] First, step S10 will be explained. First, the raw materials are weighed. According to the weight parts, 70 to 78 parts of polyester chips, 2 to 4 parts of hyperbranched styrene, 1 to 3 parts of maleic anhydride, 18 to 22 parts of nano titanium dioxide, 0.05 to 0.15 parts of initiator, 0.1 to 0.3 parts of antioxidant, and 0.3 to 0.5 parts of butyl stearate are weighed.

[0028] Add the weighed polyester chips, hyperbranched styrene, maleic anhydride, nano titanium dioxide, initiator, antioxidant, and butyl stearate to a high-speed mixer. Start the mixer and stir at high speed. The frictional heat generated by stirring will raise the temperature of the mixture to 88°C to 92°C, and the mixture will be stirred and mixed within this temperature range for 25 to 35 minutes.

[0029] Subsequently, the mixed material is conveyed to a twin-screw extruder for melt extrusion. The temperature of each heating zone of the twin-screw extruder is set between 260℃ and 280℃, and the screw speed is set between 180 rpm and 220 rpm. After being melted and plasticized in the twin-screw extruder, the material is extruded into strips, cooled by cooling water, and then fed into a pelletizer for pelletizing to obtain matte polyester functional masterbatch.

[0030] Next, step S20 will be explained. First, the core layer raw material is prepared by uniformly mixing the matte polyester functional masterbatch obtained in step S10 with polyester chips at a weight ratio of 1:3 to 1:5; at the same time, titanium dioxide-free polyester chips are prepared as the skin layer raw material. The mixed core layer raw material and skin layer raw material are respectively fed into two independent extrusion channels for melt plasticizing, wherein the melt temperature of the core layer raw material is set to 275°C to 285°C, and the melt temperature of the skin layer raw material is set to 280°C to 290°C.

[0031] The molten core and sheath layers are fed into a core-sheath composite spinning assembly for co-extrusion. The metering pump speed is adjusted to control the extruded weight ratio of the sheath to the core layer at 1:0.8 to 1:1.2. The extruded melt streams are cooled and solidified by a side-blowing cooling system, with the cooling air velocity controlled at 0.6 m / s to 1.0 m / s and the air temperature at 23°C to 27°C.

[0032] After cooling and solidification, the filament bundle then enters the drawing and false twisting texturing process. The temperature of the first hot roller is set to 80°C to 90°C, the temperature of the second hot roller is set to 105°C to 115°C, the drawing ratio is set to 1.8 to 2.2 times, and the false twisting speed is set to 9000 rpm to 11000 rpm. After the above melt spinning and texturing processing steps, matte, hygroscopic polyester fiber (DTY) is obtained.

[0033] Next, step S30 will be explained. First, two types of polypropylene terephthalate (PPT) chips are selected as raw materials. The high-viscosity chip has an intrinsic viscosity of 1.20 dL / g to 1.30 dL / g, and the low-viscosity chip has an intrinsic viscosity of 0.85 dL / g to 0.95 dL / g. These two types of chips are then fed into two separate melt extrusion channels for melting. The melting temperature for the high-viscosity chip is set to 250°C to 260°C, and the melting temperature for the low-viscosity chip is set to 240°C to 250°C.

[0034] The two molten materials are fed into a parallel composite spinning assembly for merging and co-extrusion. The metering pump is adjusted to ensure that the extruded weight ratio of the two components is 1:0.9 to 1:1.1. The extruded melt stream is cooled by a cooling air blowing system, with the air velocity controlled at 0.4 m / s to 0.6 m / s and the air temperature at 21°C to 25°C.

[0035] After cooling and solidification, the filament bundle is then stretched and wound. The temperature of the first hot roller is set to 75°C to 85°C, the temperature of the second hot roller is set to 95°C to 105°C, the stretching ratio is set to 1.4 to 1.6 times, and the winding speed is set to 3400 m / min to 3600 m / min. After the above steps, a flexible bicomponent cotton-like yarn is obtained.

[0036] Next, step S40 will be explained. The matte, sweat-absorbing polyester fiber obtained in step S20 and the flexible bicomponent cotton-like yarn obtained in step S30 are used as raw materials and fed into the twisting device at a weight ratio of 1:0.9 to 1:1.1.

[0037] During the feeding process, the tension of the two yarns is independently controlled. The feeding tension of the matte, sweat-wicking polyester fiber is set to 5.5cN to 6.5cN, and the feeding tension of the flexible bicomponent cotton-like yarn is set to 3.5cN to 4.5cN. At the same time, the twist of the twisting equipment is set to 400 twists / meter to 500 twists / meter. The two yarns are twisted together under the above tension and twist conditions, and finally wound to obtain the sweat-wicking cotton-like composite yarn.

[0038] Finally, step S50 is explained. The moisture-wicking cotton-like composite yarn is knitted, dyed, and hydrophilic finished to obtain a moisture-wicking cotton-like polyester fabric. During the knitting process, the moisture-wicking cotton-like composite yarn is prepared from matte moisture-wicking polyester fibers with a linear density of 45 dtex to 55 dtex and flexible bicomponent cotton-like yarn. This moisture-wicking cotton-like composite yarn is then woven using a circular knitting machine to obtain a knitted fabric.

[0039] The woven fabric is placed in a dyeing machine for dyeing, with the temperature controlled within the range of 110℃ to 120℃ during the dyeing process. After dyeing, the fabric undergoes a hydrophilic softening treatment, with the setting temperature set at 145℃ to 155℃. Through the above weaving, dyeing, and finishing steps, a sweat-wicking, cotton-like polyester fabric is finally produced.

[0040] To achieve the sweat-wicking function of fabrics, high concentrations of matting agents are typically added to the fibers. Half of these matting agents are titanium dioxide, and the amount added usually needs to be quite high. Current technologies often use physical blending or the addition of low-molecular-weight dispersants such as stearic acid to treat inorganic fillers. However, these dispersants are prone to thermal degradation or desorption from the particle surface during high-temperature melt spinning, leading to agglomeration of nano-titanium dioxide. These agglomerates not only clog the spinneret orifices but also cause drastic fluctuations in melt shear viscosity, resulting in a significant difference in the rheological properties of the highly filled core layer melt compared to the skin layer, making stable coating impossible.

[0041] This invention introduces a solid-phase in-situ graft polymerization process of styrene and maleic anhydride during the raw material mixing stage. Utilizing the in-situ polymerization reaction initiated by frictional heating, a heat-resistant polymer coating layer compatible with the polyester matrix is ​​constructed on the surface of titanium dioxide. This coating layer acts as a molecular lubricant in the molten state, effectively reducing the shear viscosity of the highly filled core melt and matching its rheological behavior with that of the pure polyester sheath. This achieves stable molding of high-concentration matting masterbatch in core-sheath composite spinning. However, in conventional single-component spinning, a large amount of hard particles with high filling content are still exposed on the fiber surface, leading to an increased coefficient of friction and wear on equipment during processing. This solution utilizes a core-sheath composite structure to physically isolate the particles, sealing high-concentration titanium dioxide within the fiber core. This allows the titanium dioxide to block light, while pure polyester without particles can be used as the sheath. The physical thickness of the sheath covers the internal hard particles, thus maintaining optical shielding while ensuring low friction on the fiber surface. Furthermore, the addition of rigid inorganic particles hinders the orientation and crystallization of polymer molecular chains, leading to a significant reduction in the thermal shrinkage difference of the bicomponent fibers. This prevents the fibers from forming the expected three-dimensional helical crimp, resulting in the failure of the cotton-like effect. This solution first prepares parallel bicomponent yarns as a skeleton to ensure that their crystallization kinetics are not disturbed, maintaining maximum crimp recovery force. Then, matte and sweat-wicking polyester fibers are twisted with these bicomponent yarns, allowing the matte function to function as an independent fiber without affecting the normal crimp of the bicomponent yarn. This avoids interference from inorganic particles on the fiber's microcrystalline structure, achieving a coexistence of the cotton-like effect and the sweat-wicking effect. By controlling the matte, sweat-wicking polyester fibers to a high tension state and the bicomponent yarn to a low tension state, the relaxed cotton-like bicomponent yarn during yarn spinning naturally floats on the outer layer, tightly wrapping the inner matte, sweat-wicking polyester fibers. This utilizes the outer layer of hydrophobic and fluffy cotton-like yarn to isolate the skin from the moist inner layer, improving the fabric's dry feel and fluffiness. Simultaneously, the capillary effect of the inner polyester fibers quickly wicks sweat away from the skin. Furthermore, the physical coating of the outer layer further blocks the path of light penetrating the moist yarn, forming a double barrier with the light-scattering function of the inner layer, significantly enhancing the fabric's anti-see-through effect when moisture-absorbing.

[0042] To further illustrate the technical solutions involved in this invention, the following embodiments and comparative examples are provided. It should be noted that the following embodiments and comparative examples do not constitute a limitation of this invention.

[0043] To make the description of the present invention clearer and more reproducible, the main raw materials used in the following embodiments and comparative examples are as follows: Polyester chips (PET): semi-dull grade, intrinsic viscosity (IV) of 0.64 dL / g, TiO2 content of 0.3%, purchased from Sinopec Yizheng Chemical Fiber Co., Ltd., grade BG80.

[0044] Polypropylene terephthalate (PTT) chips: High viscosity chips: intrinsic viscosity (IV) of 1.30 dL / g, purchased from Sheng Hong Group.

[0045] Low viscosity chips: intrinsic viscosity (IV) of 0.92 dL / g, purchased from Sheng Hong Group.

[0046] Nano titanium dioxide: anatase type, inorganically coated (aluminum / silicon), with an average native particle size of 30-50nm, purchased from Nanjing Dina Chemical.

[0047] Hyperbranched styrene: Industrial grade, weight average molecular weight 2000-5000, purchased from Wuhan Shiquanxing Decoration Building Materials Co., Ltd.

[0048] Maleic anhydride: purity ≥99.5%, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0049] Initiator: Azobisisobutyronitrile (AIBN), purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0050] Antioxidant: Antioxidant 1010, purchased from BASF.

[0051] Butyl stearate: Industrial grade, purchased from Jiangsu Haian Petrochemical Plant.

[0052] Example 1 This embodiment provides a method for preparing a sweat-wicking, cotton-like polyester fabric, the specific steps of which are as follows: S10: 74.3 kg of polyester chips, 3 kg of hyperbranched styrene, 2 kg of maleic anhydride, 20 kg of nano-titanium dioxide, 0.1 kg of initiator, 0.2 kg of antioxidant, and 0.4 kg of butyl stearate are added to a high-speed mixer. Stirring is started, and the mixture is heated to 90°C using friction heating and held at this temperature for 30 minutes to allow in-situ graft polymerization of the monomers in a solid-state state. The mixture is then fed into a twin-screw extruder, with each zone temperature set at 260-280°C and the screw speed at 200 rpm. Extrusion granulation yields matte polyester functional masterbatch.

[0053] S20: The matte polyester functional masterbatch and polyester chips are mixed at a weight ratio of 1:4 as the core layer raw material, and the titanium dioxide-free polyester chips are used as the sheath layer raw material. They are melted at 280℃ (core layer) and 285℃ (sheath layer) respectively, then combined for core-sheath composite extrusion, with a core-sheath weight ratio of 1:1. After cooling with a side-blowing airflow of 0.8 m / s and 25℃, the mixture is stretched and deformed on the first hot roller (85℃) and the second hot roller (110℃) (stretch ratio 2.0, false twist speed 10000 rpm) to obtain 50 dtex / 48f ultra-matte, sweat-reducing polyester fiber (DTY).

[0054] S30: High-viscosity PTT chips with an intrinsic viscosity of 1.30 dL / g and low-viscosity PTT chips with an intrinsic viscosity of 0.92 dL / g are selected and melted at 255℃ and 245℃, respectively. They are then co-extruded using parallel composite components (weight ratio 1:1), cooled by a ring blower at 0.5 m / s and 23℃, and subjected to stretching (first hot roller 80℃, second hot roller 100℃, stretch ratio 1.5) and winding (3500 m / min) to obtain a 50 dtex / 48f flexible bicomponent cotton-like yarn.

[0055] S40: Feed the two types of yarn into the twisting device at a 1:1 weight ratio. Control the tension of the ultra-dull DTY to 6.0 cN, the tension of the flexible imitation cotton yarn to 4.0 cN, and the twist to 450 twists / meter to obtain a moisture-wicking imitation cotton composite yarn.

[0056] S50: The above-mentioned composite yarn is selected, woven on a circular knitting machine, dyed with disperse dye (115℃), and hydrophilic softening finishing (150℃ setting) to obtain the finished fabric.

[0057] Example 2 This embodiment provides a method for preparing a moisture-wicking, cotton-like polyester fabric. The difference from Embodiment 1 lies in the adjustment of some parameters. The specific steps are as follows: S10: Raw material usage adjusted to: 78kg polyester chips, 2kg hyperbranched styrene, 1kg maleic anhydride, 18kg nano titanium dioxide, and 0.05kg initiator. Insulation temperature: 88℃, Insulation time: 35 minutes.

[0058] S20: The mixing ratio of core material is adjusted to 1:5 (masterbatch: chips), and the weight ratio of skin and core is adjusted to 1:1.2.

[0059] S30: The intrinsic viscosity of high-viscosity PTT is selected as 1.20 dL / g, and the intrinsic viscosity of low-viscosity PTT is selected as 0.85 dL / g.

[0060] S40: Control the feeding tension of ultra-dull DTY to 5.5cN, the feeding tension of flexible imitation cotton yarn to 3.5cN, and the twist to 400 twists / meter.

[0061] The remaining steps and parameters are consistent with those in Example 1.

[0062] Example 3 This embodiment provides a method for preparing a moisture-wicking, cotton-like polyester fabric. The difference from Embodiment 1 lies in the adjustment of some parameters. The specific steps are as follows: S10: Raw material usage adjusted to: 70kg polyester chips, 4kg hyperbranched styrene, 3kg maleic anhydride, 22kg nano titanium dioxide, and 0.15kg initiator. Insulation temperature: 92℃, Insulation time: 25 minutes.

[0063] S20: The mixing ratio of core material is adjusted to 1:3 (masterbatch: chips), and the weight ratio of skin and core is adjusted to 1:0.8.

[0064] S40: Control the feeding tension of ultra-dull DTY to 6.5cN, the feeding tension of flexible imitation cotton yarn to 4.5cN, and the twist to 500 twists / meter.

[0065] The remaining steps and parameters are consistent with those in Example 1.

[0066] Comparative Example 1 The only difference between this comparative example and Example 1 is the preparation method of the masterbatch in step S10.

[0067] The specific differences are as follows: instead of adding hyperbranched styrene, maleic anhydride, and initiators, 3 kg of stearic acid (a traditional dispersant) is added. The mixing process does not involve a temperature-controlled reaction at 88-92°C; instead, the mixture is directly physically mixed and then fed into an extruder for granulation. The remaining steps are exactly the same as in Example 1.

[0068] Comparative Example 2 The only difference between this comparative example and Example 1 is the different DTY preparation structure in step S20.

[0069] The specific difference is that the core-sheath composite spinning process is not used. The matte masterbatch prepared by S10 is mixed with polyester chips at a 1:4 ratio and then directly subjected to single-component melt spinning (i.e., a fully filled structure), without a pure polyester sheath. All other spinning parameters and subsequent steps are exactly the same as in Example 1.

[0070] Comparative Example 3 The only difference between this comparative example and Example 1 is the preparation method of the cotton-like yarn in step S30.

[0071] The specific difference is that high and low viscosity parallel composite spinning is not used. Instead, conventional single-component spinning is performed using PTT chips with a single intrinsic viscosity (1.02 dL / g), which cannot form a helical crimp structure. The remaining steps are exactly the same as in Example 1.

[0072] Comparative Example 4 The only difference between this comparative example and Example 1 is the process control of twisting the yarn in step S40.

[0073] The specific difference is that during feeding, no tension difference is set, and the feeding tension of both the ultra-dull DTY and the flexible cotton-like yarn is controlled at 5.0 cN. The remaining steps are exactly the same as in Example 1.

[0074] The performance of the sweat-wicking imitation cotton polyester fabrics prepared in Examples 1-3 and Comparative Examples 1-4 was tested, and the test methods are as follows: Sweat stain concealment performance (wet-state anti-see-through property): The test was modified based on the optical principles of GB / T 24218.15-2018 "Textiles - Nonwovens - Test Methods - Part 15: Determination of air permeability". 0.5 ml of artificial sweat was added to the fabric to moisten it, and after standing for 1 minute, its light transmittance was measured. The lower the light transmittance, the better the sweat stain concealment effect. Simultaneously, a gray card was used for visual evaluation (1-5 levels, with 5 being the best, indicating minimal color change after wetting and no visible sweat stains).

[0075] Cotton-like feel (surface friction coefficient): The dynamic friction coefficient (MIU) of the fabric surface was tested using a KES-FB4 surface performance tester. The lower the value, the smoother the surface and the softer the feel. Five professionals were also invited to provide subjective feel ratings (1-10 points, with 10 points indicating excellent cotton-like fluffiness).

[0076] Broken yarn rate: The number of times the yarn breaks during the full roll in step S20 spinning process (times / ton).

[0077] Drying rate: Refer to GB / T 21655.1-2008 "Evaluation of the moisture absorption and quick-drying properties of textiles - Part 1: Single combination test method" to test the evaporation rate (g / h).

[0078] The test results are as follows:

[0079] Comparing the test data of Example 1 and Comparative Example 1 reveals that the spinning breakage rate of Comparative Example 1 is significantly higher than that of Example 1, while its hand feel score is much lower and its surface friction coefficient is higher. This result indicates that the traditional stearic acid physical dispersion method used in Comparative Example 1 fails under high-temperature spinning conditions, leading to the agglomeration of titanium dioxide particles. The large particles formed by agglomeration not only clog the spinning components, causing frequent fiber breakage, but also protrude from the fiber surface, resulting in a rough hand feel. In contrast, step S10 of this invention generates a heat-resistant grafted coating layer through in-situ polymerization, achieving monodispersion of nanoparticles and effectively solving the processing stability problem of high-filler spinning.

[0080] Further comparing Example 1 and Comparative Example 2, while Comparative Example 2 achieved a certain level of sweat-concealing capability in terms of light transmittance, its coefficient of dynamic friction was relatively high, resulting in a rough feel. This is because Comparative Example 2 eliminated the core-sheath structure, causing a high concentration of hard titanium dioxide particles to be directly exposed on the fiber surface. In step S20 of this invention, a pure polyester sheath physically covers the core particles, reducing the coefficient of friction to a lower level while maintaining the same sweat-concealing capability, thus achieving both sweat-concealing function and a smooth feel.

[0081] Comparative Example 3 had an extremely low hand feel score and a decreased drying rate. This was attributed to its use of a single-component polyethylene terephthalate (PET), which prevented the formation of a spiral crimp structure. Due to the lack of a crimped skeleton, the fabric became stiff and lacked fluffiness, feeling similar to ordinary synthetic fibers, and also lost its moisture-pumping effect, resulting in slower drying. Step S30 of this invention, through specific high- and low-viscosity parallel spinning, endows the fabric with excellent cotton-like fluffiness and quick-drying properties.

[0082] The comparison between Example 1 and Comparative Example 4 illustrates the importance of tension control. In Comparative Example 4, where the feeding tension difference was not controlled, the fabric's wet light transmittance increased, indicating a poorer moisture-wicking effect, while the drying rate also decreased. This is because the lack of tension difference caused the hydrophilic matte fibers and the hydrophobic cotton-like yarn to mix randomly, failing to form an inner absorbent and outer elastic covering structure. The wet matte fibers exposed on the outer layer easily let the color show through, and the lack of a hydrophobic outer layer resulted in a noticeable damp and cold feeling on the body. Step S40 of this invention utilizes the tension difference to force the cotton-like yarn to cover the outer layer, forming a double optical barrier and a one-way moisture-wicking channel, improving the synergistic effect of moisture wicking and quick-drying.

[0083] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A method for preparing a sweat-wicking, cotton-like polyester fabric, characterized in that, The method includes the following steps: S10: Polyester chips, hyperbranched styrene, maleic anhydride, nano titanium dioxide and initiator are mixed, heated to 88-92℃ by stirring and kept at that temperature, and then melt extruded and granulated to obtain matte polyester functional masterbatch. S20: The matte polyester functional masterbatch and polyester chips are mixed at a weight ratio of 1:3-5 as the core layer material, and the polyester chips without titanium dioxide are used as the sheath material. They are melted separately, and then combined for sheath-core composite extrusion, cooling and blowing, stretching and false twisting deformation to obtain matte sweat-proof polyester fiber. S30: Select high-viscosity polyethylene terephthalate (PET) chips with an intrinsic viscosity of 1.20-1.30 dL / g and low-viscosity PET chips with an intrinsic viscosity of 0.85-0.95 dL / g, melt them separately, and then combine them for parallel composite extrusion, cooling and blowing, stretching and winding to obtain flexible bicomponent cotton-like yarn; S40: The matte, sweat-wicking polyester fiber and the flexible bicomponent cotton-like yarn are fed in simultaneously and twisted, wherein the feeding tension of the matte, sweat-wicking polyester fiber is controlled to be 5.5-6.5 cN and the feeding tension of the flexible bicomponent cotton-like yarn is controlled to be 3.5-4.5 cN, to obtain a sweat-wicking cotton-like composite yarn. S50: The sweat-wicking imitation cotton composite yarn is used as raw material to make the sweat-wicking imitation cotton polyester fabric.

2. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, The weight proportions of each raw material in S10 are as follows: 70-78 parts polyester chips, 2-4 parts hyperbranched styrene, 1-3 parts maleic anhydride, 18-22 parts nano titanium dioxide, 0.05-0.15 parts initiator, 0.1-0.3 parts antioxidant, and 0.3-0.5 parts butyl stearate.

3. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S10, the heat preservation time is 25-35 minutes; the temperature of each temperature zone during melt extrusion is set in the range of 260-280℃, and the screw speed is set to 180-220 rpm.

4. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S20, the weight ratio of the skin layer to the core layer in the skin-core composite extrusion is set to 1:0.8-1.2; the melting temperature of the core layer raw material is set to 275-285℃, and the melting temperature of the skin layer raw material is set to 280-290℃.

5. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S20, the wind speed of the cooling air blower is controlled within the range of 0.6-1.0 m / s, and the air temperature is controlled within the range of 23-27℃.

6. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S20, the process parameters for stretching and false twisting are: the temperature of the first hot roller is 80-90℃, the temperature of the second hot roller is 105-115℃, the stretching ratio is set to 1.8-2.2, and the false twisting speed is set to 9000-11000 rpm.

7. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S30, the weight ratio of the two components in the parallel composite extrusion is set to 1:0.9-1.1; the melting temperature corresponding to the high viscosity chips is set to 250-260℃, and the melting temperature corresponding to the low viscosity chips is set to 240-250℃.

8. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S30, the cooling air velocity is 0.4-0.6 m / s and the air temperature is 21-25℃; the process parameters for stretching and winding are: the temperature of the first hot roller is 75-85℃, the temperature of the second hot roller is 95-105℃, the stretching ratio is set to 1.4-1.6, and the winding speed is set to 3400-3600 m / min.

9. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S40, the feeding weight ratio of the matte, sweat-absorbing polyester fiber to the flexible bicomponent cotton-like yarn is 1:0.9-1.1; the twist is set to 400-500 twists / meter.

10. The method for preparing a sweat-wicking imitation cotton polyester fabric as described in claim 1, characterized in that, In S50, the sweat-wicking imitation cotton composite yarn is knitted, dyed, and hydrophilic finished to obtain the sweat-wicking imitation cotton polyester fabric; the linear density of the matte sweat-wicking polyester fiber and the flexible bicomponent imitation cotton yarn used in the knitting is 45-55 dtex; the dyeing temperature is controlled in the range of 110-120℃, and the setting temperature of the hydrophilic softening finish is controlled in the range of 145-155℃.

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