Four-way stretch fabric and preparation method thereof

Abstract

The invention discloses a spandex fabric and a preparation method thereof, and relates to the technical field of functional fiber fabrics. The method comprises the following steps: firstly, preparing a modified polyester chip with permanent body phase hydrophilicity through copolymerization and cross-linking of multi-component monomers, and spinning into a fiber; then, the fibers are subjected to plasma activation and graft polymerization to form an organic-inorganic hybrid hydrophilic surface layer which is supported by a nano silicon dioxide skeleton and is rich in nano pores, and the surface gel barrier effect is effectively overcome. Blending the prepared modified polyester fibers and the pretreated polyamide fibers into yarns, finally knitting the yarns and spandex yarns, and performing relaxation treatment to obtain the finished fabric. Through synergistic modification of the body phase and the surface, the fabric has excellent lasting hydrophilicity, efficient moisture absorption and sweat releasing functions and good four-side elasticity and wearing comfort.

Description

Technical Field

[0001] This invention relates to the field of functional fiber fabric technology, specifically to a four-way stretch fabric and its preparation method. Background Technology

[0002] Polyester fibers (such as polyethylene terephthalate, PET) have outstanding characteristics such as high strength, excellent abrasion resistance, and good dimensional stability. They also have the advantages of strong chemical corrosion resistance, good heat resistance, and moderate production cost, making them suitable for large-scale industrial production. Nylon fibers (such as nylon 6 and nylon 66) have excellent elastic recovery and fatigue resistance. They can quickly rebound to their original state after being stretched. They are not prone to loosening or wrinkling after long-term wear and have a soft and smooth feel, providing excellent comfort when in contact with the skin. The four-way stretch fabric, prepared by blending and interweaving processes, combines the high strength and dimensional stability of polyester fiber with the high elasticity and soft touch of nylon fiber. With its perfect balance of mechanical properties and elasticity, it is widely used in sportswear (such as running clothes and basketball clothes), underwear (such as underwear and thermal clothing), casual wear, outdoor clothing, yoga wear, swimwear and other fields. It can meet the needs of clothing stretching freedom and wear resistance in sports scenarios, and also meet the needs of softness, comfort and shape retention in daily wear, fully meeting the market's dual expectations for fabric comfort and practicality. However, polyester fiber molecules are composed of a large number of hydrophobic ester bonds and methylene groups. The molecular chain structure is regular and dense and lacks hydrophilic groups, making it inherently highly hydrophobic, far less so than natural fibers and nylon fibers. This inherent defect leads to the common problem of weak moisture absorption and wicking ability in polyester / nylon composite four-way stretch fabrics. During exercise or in hot and humid environments, the sweat secreted by the human body cannot be quickly absorbed by the fabric and conducted to the surface for evaporation. Instead, it can only adhere to the skin surface, forming a damp, cold, and sticky feeling. At the same time, the hydrophobicity of the fabric hinders air circulation, making it difficult for heat and moisture to dissipate, thus producing a significant feeling of stuffiness. This discomfort is significantly aggravated, especially in summer or after prolonged exercise. Summary of the Invention

[0003] The purpose of this invention is to provide a four-way stretch fabric and its preparation method, so as to solve the technical problem of poor hydrophilicity and moisture absorption of polyester / nylon composite four-way stretch fabric mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for preparing a four-way stretch fabric includes the following steps:

[0006] (1) Dimethyl terephthalate, ethylene glycol, polyethylene glycol, sodium salt of 5-sulfonic acid dimethyl isophthalate and zinc acetate catalyst are mixed and heated under inert gas protection. Then, trimethyl hydroxyethyl terephthalate crosslinking agent, antimony trioxide catalyst and triphenyl phosphate heat stabilizer are added. First, pre-condensation is carried out at normal pressure, and then vacuum heating is carried out for final condensation. After the reaction is completed, hydrophilic modified polyester chips are obtained by extrusion, cooling and pelletizing.

[0007] (2) After drying the hydrophilic modified polyester chips, melt spinning was performed, followed by cooling, hot stretching and heat setting to obtain nascent fibers;

[0008] (3) The nascent fiber was subjected to plasma treatment, and then the nascent fiber was immersed in a reaction solution containing acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, β-cyclodextrin, KH-570 modified nano silica and ammonium persulfate-sodium bisulfite initiation system for constant temperature reaction. After the reaction, it was rinsed with hot water, washed and dried to obtain modified polyester fiber.

[0009] (4) Immerse the nylon fiber in a fatty alcohol polyoxyethylene ether aqueous solution at a constant temperature, then wash it with deionized water and dry it to obtain pretreated nylon fiber.

[0010] (5) The modified polyester fiber is mixed with the pretreated nylon fiber, and after spraying with antistatic oil, it is processed through opening and cleaning, carding, drawing, roving and spinning processes to obtain the blended yarn.

[0011] (6) Using a double-sided weft knitting circular knitting machine, the blended yarn is used as the ground yarn and spandex yarn is used as the elastic yarn for knitting. After knitting into a greige fabric, it is subjected to relaxation heat treatment and cooling to obtain a four-way stretch fabric.

[0012] In this invention, the hydrophilic and hygroscopic properties of polyester fibers are synergistically improved in the following ways: Firstly, a stable and uniform bulk hydrophilic system is constructed through copolymerization of multiple monomers, thereby altering the hydrophobic nature of polyester fibers. Specifically, during the modification process, flexible hydrophilic segments (PEG-1000) and ionic hydrophilic groups (sulfonate groups provided by sodium dimethyl isophthalate 5-sulfonate) are used as comonomers and permanently embedded in the polyester molecular backbone in the form of covalent bonds, forming a composite molecular structure of rigid polyester backbone - flexible PEG hydrophilic segments - strongly polar sulfonate groups. The flexible PEG segments increase the degree of freedom and structural looseness of the molecular chain, breaking the traditional tightly packed hydrophobic structure of polyester molecular chains and providing channels for water penetration; the sulfonate groups, as strongly hydrophilic sites, can actively bind water molecules through ion adsorption, while simultaneously increasing the polarity of the molecular chain and enhancing the interaction force with water molecules. Furthermore, the mild three-dimensional network structure constructed by the crosslinking agent TMP not only fixes the distribution of hydrophilic segments and groups, preventing their aggregation or migration during processing, but also forms fine molecular-level channels, accelerating the conduction and diffusion of moisture within the fiber. This modification method achieves deep integration of hydrophilic properties with the polyester matrix, giving polyester chips and subsequent fibers permanent and uniform bulk hydrophilicity. This allows for the active adsorption and storage of moisture from within the fiber, rather than relying solely on surface adhesion, providing a core foundation for long-lasting hydrophilic and moisture-wicking properties in fabrics. Simultaneously, it maintains the thermal stability and spinnability of polyester, ensuring smooth subsequent spinning and weaving processes and preventing a decline in fiber mechanical properties due to modification.

[0013] On the other hand, by combining plasma pretreatment and hydrophilic graft polymerization, a highly efficient hydrophilic functional layer is constructed on the fiber surface, forming a synergistic effect with the hydrophilic structure in the first aspect, thus significantly improving the hydrophilic and moisture-absorbing properties. In the plasma pretreatment stage, high-energy active particles bombard the fiber surface, forming uniformly distributed micro-nano-scale pits and grooves through physical etching, significantly increasing the fiber's specific surface area and surface roughness, creating a capillary effect and providing more physical sites for moisture adsorption. Furthermore, it breaks the chemical bonds of the fiber surface molecules, introducing a large number of oxygen-containing polar groups such as hydroxyl and carboxyl groups, as well as free radical active sites. These active sites act as anchors, significantly enhancing the reactivity and bonding strength of subsequent graft polymerization, fundamentally solving the problems of easy detachment and poor durability of traditional surface-modified layers. In the subsequent hydrophilic graft polymerization process, acrylamide and 2-acrylamide-2-methylpropanesulfonic acid monomers undergo free radical polymerization at the active sites on the fiber surface under the action of the initiation system, forming a P(AM-co-AMPS) hydrophilic copolymer graft layer covalently bonded to the fiber matrix. This grafted layer combines high hydrophilicity with a porous structure: the amide groups of acrylamide can form hydrogen bonds with water molecules, quickly absorbing external moisture; the sulfonate groups of 2-acrylamido-2-methylpropanesulfonic acid further enhance water absorption capacity, while improving the wash resistance and stability of the grafted layer; the porous structure accelerates the conduction of moisture from the surface to the fiber interior. This ultimately creates a synergistic effect of superhydrophilic surface layer for rapid water capture and hydrophilic bulk layer for efficient water storage and conduction. This solves the problems of weak water retention and easy degradation associated with single surface modification, and also compensates for the slow moisture absorption rate of single bulk modification. This gives the fiber hydrophilic properties of rapid moisture absorption, efficient water retention, and long-lasting wash resistance, thus endowing the fabric with excellent moisture-wicking properties. When worn, it can quickly absorb sweat from the skin surface and conduct it to the outer layer of the fabric for evaporation, keeping the skin dry.

[0014] Preferably, in step (1), the mass ratio of dimethyl terephthalate to ethylene glycol is 10:(5-7).

[0015] Preferably, in step (1), the mass ratio of dimethyl terephthalate to polyethylene glycol is 10:(0.7-0.9).

[0016] Preferably, in step (1), the mass ratio of dimethyl terephthalate to sodium 5-sulfonic acid dimethyl isophthalate is 10:(0.3-0.5).

[0017] Preferably, in step (2), the heat setting temperature is 120-125°C and the heat setting time is 30-40 seconds.

[0018] Preferably, in step (3), the mass ratio of acrylamide to 2-acrylamide-2-methylpropanesulfonic acid is 4:(1-2).

[0019] Preferably, in step (3), the mass ratio of β-cyclodextrin to KH-570 modified nano-silica is 5:(1-3).

[0020] In experiments, this invention revealed that although the first modification endowed the fiber with good internal water storage capacity, and the second surface grafting polymerization formed a P(AM-co-AMPS) hydrophilic layer capable of rapidly capturing water, this surface layer instantly absorbs water and swells highly upon contact with sweat, forming a dense hydrogel-like "water film." This film, in turn, becomes a mass transfer resistance layer, severely hindering the rapid conduction of water from the fiber surface to the internal bulk hydrophilic region, resulting in a wet, cold, and sticky surface, while the internal moisture absorption potential cannot be utilized in a timely manner, thus limiting the overall kinetic efficiency of moisture absorption and perspiration. To further address this technical challenge, β-cyclodextrin (β-CD) and KH-570-modified nano-silica were introduced into the graft polymerization step. Specifically, the functionalized nano-SiO2 particles participated in the copolymerization reaction through their surface methacryloyloxy groups, forming an inorganically reinforced rigid framework as multifunctional crosslinking points. This significantly improved the mechanical strength and dimensional stability of the grafted layer, preventing excessive densification during swelling. Simultaneously, β-cyclodextrin molecules were physically embedded within the growing polymer network during polymerization and subsequently removed by hot water washing, leaving numerous stable nanoscale pores in their original locations. The combined effect of these two factors is that the nano-SiO2 framework effectively supports and fixes these porous structures, preventing them from collapsing and closing during polymer swelling; these pores also constitute a "highway" for rapid water transport, allowing water to bypass the swollen polymer chains, directly penetrate the grafted layer, and quickly be directed into the fiber interior. Ultimately, an organic-inorganic hybrid functional layer with high hydrophilicity, stable porous structure and excellent wear resistance was formed on the fiber surface, which fundamentally broke the gel barrier and achieved efficient kinetic matching between surface instantaneous adsorption and bulk water storage.

[0021] Preferably, in step (4), the concentration of the fatty alcohol polyoxyethylene ether aqueous solution is 2-4 wt%.

[0022] Preferably, in step (5), the mass ratio of modified polyester fiber to pretreated nylon fiber is 6:(3-5).

[0023] A four-way stretch fabric is prepared by the method described above.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. By copolymerizing, flexible hydrophilic segments and ionic hydrophilic groups are permanently embedded into the polyester molecular chain by covalent bonds, and fixed by cross-linking structure. This fundamentally changes the hydrophobic nature of the fiber and forms a stable and uniform bulk hydrophilic system, providing a channel for long-term storage and internal conduction of moisture.

[0026] 2. By combining plasma activation with nanoporous hybrid grafting for surface modification, a hydrophilic functional layer with high activity, strong adhesion and stable porous structure was constructed on the fiber surface. This not only enabled instantaneous water capture, but also effectively prevented gel blockage through the pore network supported by the rigid nanoframework, ensuring efficient and rapid water conduction from the surface to the bulk phase. Attached Figure Description

[0027] Figure 1 This is a SEM image of the modified polyester fiber prepared in Example 4 of the present invention.

[0028] Figure 2 The XPS spectrum of the four-way stretch fabric prepared in Example 4 of this invention is shown. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] A method for preparing a four-way stretch fabric includes the following steps:

[0032] (1) By weight, 100 parts of dimethyl terephthalate, 65 parts of ethylene glycol, 8.5 parts of polyethylene glycol with a number average molecular weight of 1000, 4.5 parts of sodium salt of 5-sulfonic acid dimethyl isophthalate and 0.03 parts of zinc acetate catalyst were added to the transesterification vessel. The temperature was raised to 190°C under nitrogen protection and the reaction was maintained for 3.5 h until the methanol distilled off reached more than 95% of the theoretical amount. Then, 0.02 parts of trimethylhydroxyethyl terephthalate were added to the system. The dimethyl methacrylate crosslinking agent, 0.04 parts antimony trioxide catalyst, and 0.15 parts triphenyl phosphate heat stabilizer were first subjected to a pre-condensation reaction at atmospheric pressure and 240℃ for 1.5 h. Then, the vacuum was gradually reduced to 50 Pa over 1.5 h, and the temperature was raised to 275℃ for a final condensation reaction for 4.5 h. The reaction was stopped when the intrinsic viscosity reached 0.68 dL / g. The melt was extruded through an extruder, cooled with cooling water, and pelletized to obtain hydrophilic modified polyester chips.

[0033] (2) The hydrophilic modified polyester chips were placed in a vacuum drying oven and dried continuously at 120°C for 10 hours to reduce the moisture content to below 0.02%. Then, they were fed into a melt spinning machine and the spinning temperature was set to 280°C. The melt was extruded through a spinneret with a diameter of 0.25 mm and cooled into filaments by side blowing air at 28°C. The nascent filaments were fed into a drawing machine and subjected to 4.0 times hot drawing at 85°C. Then, they were heat-set at 123°C for 35 seconds to obtain modified polyester nascent fibers.

[0034] (3) Five parts of nano-silica with an average particle size of 20 nm were dispersed in a mixed solution of 150 parts of ethanol and water (volume ratio 4:1). After ultrasonic dispersion for 30 min, 1.5 parts of KH-570 silane coupling agent were added. The pH value was adjusted to 4.5 with glacial acetic acid. The reaction was refluxed at 75 °C for 5 h. After the reaction was completed, the nano-silica was centrifuged, washed three times with ethanol, and dried in a vacuum drying oven at 60 °C to obtain KH-570 modified nano-silica.

[0035] The modified nascent polyester fibers were placed in a plasma treatment instrument, evacuated to 15 Pa, and then a mixture of argon and oxygen in a volume ratio of 3:1 was introduced. The mixture was treated at 180 W power and 13.56 MHz frequency for 4 min. The treated fibers were then immersed in a grafting reaction solution with a bath ratio of 1:20. This reaction solution consisted of 10 wt% mixed monomers (acrylamide and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 4:1.8), 2.0% β-cyclodextrin, 1.0% KH-570 modified nano-silica, and 0.4% ammonium persulfate-sodium bisulfite initiation system (1:1 mass ratio). The pH was adjusted to 5.0 with acetic acid, and the reaction was carried out at 55 °C for 2.5 h. After the reaction, the fibers were rinsed with hot water at 90 °C, washed with deionized water, and dried at 85 °C for 2.5 h to obtain the modified polyester fibers.

[0036] (4) Select 60D nylon 66 elastic yarn and immerse it in a 3.5% fatty alcohol polyoxyethylene ether aqueous solution at a bath ratio of 1:30. Soak at a constant temperature of 65℃ for 35 minutes, stirring once every 10 minutes during the soaking. After soaking, wash the fiber repeatedly with deionized water until there is no residual agent on the surface, and then dry it at 75℃ to constant weight to obtain pretreated nylon fiber.

[0037] (5) The modified polyester fiber and the pretreated nylon fiber are thoroughly mixed at a mass ratio of 6:4.5. An antistatic oil agent (prepared by mixing potassium alkyl phosphate salt and polyoxyethylene castor oil at a mass ratio of 1:1) is sprayed evenly onto the mixed fiber at a mass ratio of 0.8% of the total fiber mass and stirred evenly. Then the fiber is fed into the spinning machine and passes through the opening and cleaning, carding, drawing, roving and spinning processes in sequence. The twist of the spinning process is set to 900 twists / meter to obtain the blended yarn.

[0038] (6) The fabric is woven using a double-sided weft knitting circular knitting machine. The blended yarn is used as the ground yarn, and 45D spandex yarn is selected as the elastic yarn. The spandex yarn feed rate is controlled to be 18% of the ground yarn mass. The loom speed is set to 320 r / min, the needle pitch is 13 stitches / inch, the horizontal density is 30 rows / cm, and the vertical density is 28 loops / cm. The woven fabric is placed in a relaxation machine and treated at 85°C for 35 min. Then it is taken out and naturally cooled to room temperature to obtain the four-way stretch fabric.

[0039] Example 2

[0040] A method for preparing a four-way stretch fabric includes the following steps:

[0041] (1) By weight, 100 parts of dimethyl terephthalate, 55 parts of ethylene glycol, 7.5 parts of polyethylene glycol with a number average molecular weight of 1000, 3.5 parts of sodium salt of 5-sulfonic acid dimethyl isophthalate and 0.03 parts of zinc acetate catalyst were added to the transesterification vessel. The temperature was raised to 190°C under nitrogen protection and the reaction was maintained for 3.5 h until the methanol distillation reached more than 95% of the theoretical amount. Then, 0.02 parts of trimethylhydroxyethyl terephthalate were added to the system. The dimethyl methacrylate crosslinking agent, 0.04 parts antimony trioxide catalyst, and 0.15 parts triphenyl phosphate heat stabilizer were first subjected to a pre-condensation reaction at atmospheric pressure and 240℃ for 1.5 h. Then, the vacuum was gradually reduced to 50 Pa over 1.5 h, and the temperature was raised to 275℃ for a final condensation reaction for 4.5 h. The reaction was stopped when the intrinsic viscosity reached 0.68 dL / g. The melt was extruded through an extruder, cooled with cooling water, and pelletized to obtain hydrophilic modified polyester chips.

[0042] (2) The hydrophilic modified polyester chips were placed in a vacuum drying oven and dried continuously at 120°C for 10 hours to reduce the moisture content to below 0.02%. Then, they were fed into a melt spinning machine and the spinning temperature was set to 280°C. The melt was extruded through a spinneret with a diameter of 0.25 mm and cooled into filaments by side blowing air at 28°C. The nascent filaments were fed into a drawing machine and subjected to 4.0 times hot drawing at 85°C. Then, they were heat-set at 123°C for 35 seconds to obtain modified polyester nascent fibers.

[0043] (3) Five parts of nano-silica with an average particle size of 20 nm were dispersed in a mixed solution of 150 parts of ethanol and water (volume ratio 4:1). After ultrasonic dispersion for 30 min, 1.5 parts of KH-570 silane coupling agent were added. The pH value was adjusted to 4.5 with glacial acetic acid. The reaction was refluxed at 75 °C for 5 h. After the reaction was completed, the nano-silica was centrifuged, washed three times with ethanol, and dried in a vacuum drying oven at 60 °C to obtain KH-570 modified nano-silica.

[0044] The modified nascent polyester fibers were placed in a plasma treatment instrument, evacuated to 15 Pa, and then a mixture of argon and oxygen in a volume ratio of 3:1 was introduced. The mixture was treated for 4 min at a power of 180 W and a frequency of 13.56 MHz. The treated fibers were then immersed in a grafting reaction solution with a bath ratio of 1:20. The reaction solution consisted of 10 wt% mixed monomers (acrylamide and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 4:1.2), 2.0% β-cyclodextrin, 0.6% KH-570 modified nano-silica, and 0.4% ammonium persulfate-sodium bisulfite initiation system (1:1 mass ratio). The pH was adjusted to 5.0 with acetic acid, and the reaction was carried out at a constant temperature of 55 °C for 2.5 h. After the reaction, the fibers were rinsed with hot water at 90 °C, washed with deionized water, and dried at 85 °C for 2.5 h to obtain the modified polyester fibers.

[0045] (4) Select 60D nylon 66 elastic yarn and immerse it in a 2.5% fatty alcohol polyoxyethylene ether aqueous solution at a bath ratio of 1:30. Soak at a constant temperature of 65℃ for 35 minutes, stirring once every 10 minutes during the soaking. After soaking, wash the fiber repeatedly with deionized water until there is no residual agent on the surface, and then dry it at 75℃ to constant weight to obtain pretreated nylon fiber.

[0046] (5) The modified polyester fiber and the pretreated nylon fiber are thoroughly mixed at a mass ratio of 6:3.5. An antistatic oil agent (prepared by mixing potassium alkyl phosphate salt and polyoxyethylene castor oil at a mass ratio of 1:1) is sprayed evenly onto the mixed fiber at a mass ratio of 0.8% of the total fiber mass and stirred evenly. Then the fiber is fed into the spinning machine and passes through the opening and cleaning, carding, drawing, roving and spinning processes in sequence. The twist of the spinning process is set to 900 twists / meter to obtain the blended yarn.

[0047] (6) The fabric is woven using a double-sided weft knitting circular knitting machine. The blended yarn is used as the ground yarn, and 45D spandex yarn is selected as the elastic yarn. The spandex yarn feed rate is controlled to be 18% of the ground yarn mass. The loom speed is set to 320 r / min, the needle pitch is 13 stitches / inch, the horizontal density is 30 rows / cm, and the vertical density is 28 loops / cm. The woven fabric is placed in a relaxation machine and treated at 85°C for 35 min. Then it is taken out and naturally cooled to room temperature to obtain the four-way stretch fabric.

[0048] Example 3

[0049] A method for preparing a four-way stretch fabric includes the following steps:

[0050] (1) By weight, 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, 8 parts of polyethylene glycol with a number average molecular weight of 1000, 4 parts of sodium salt of 5-sulfonic acid dimethyl isophthalate and 0.03 parts of zinc acetate catalyst were added to the transesterification vessel. The temperature was raised to 190°C under nitrogen protection and the reaction was kept at the temperature for 3.5 h until the methanol distillation reached more than 95% of the theoretical amount. Then, 0.02 parts of trimethyl hydroxyethyl terephthalate crosslinking agent, 0.04 parts of antimony trioxide catalyst and 0.15 parts of triphenyl phosphate heat stabilizer were added to the system. The pre-condensation reaction was carried out at atmospheric pressure and 240°C for 1.5 h. Then, the vacuum was gradually reduced to 50 Pa within 1.5 h and the temperature was raised to 275°C for the final condensation reaction for 4.5 h. The reaction was stopped when the intrinsic viscosity reached 0.68 dL / g. The melt was extruded through an extruder, cooled with cooling water and pelletized to obtain hydrophilic modified polyester chips.

[0051] (2) The hydrophilic modified polyester chips were placed in a vacuum drying oven and dried continuously at 120°C for 10 hours to reduce the moisture content to below 0.02%. Then, they were fed into a melt spinning machine and the spinning temperature was set to 280°C. The melt was extruded through a spinneret with a diameter of 0.25 mm and cooled into filaments by side blowing air at 28°C. The nascent filaments were fed into a drawing machine and subjected to 4.0 times hot drawing at 85°C. Then, they were heat-set at 123°C for 35 seconds to obtain modified polyester nascent fibers.

[0052] (3) Five parts of nano-silica with an average particle size of 20 nm were dispersed in a mixed solution of 150 parts of ethanol and water (volume ratio 4:1). After ultrasonic dispersion for 30 min, 1.5 parts of KH-570 silane coupling agent were added. The pH value was adjusted to 4.5 with glacial acetic acid. The reaction was refluxed at 75 °C for 5 h. After the reaction was completed, the nano-silica was centrifuged, washed three times with ethanol, and dried in a vacuum drying oven at 60 °C to obtain KH-570 modified nano-silica.

[0053] The modified nascent polyester fibers were placed in a plasma treatment instrument, evacuated to 15 Pa, and then a mixture of argon and oxygen in a volume ratio of 3:1 was introduced. The mixture was treated for 4 min at a power of 180 W and a frequency of 13.56 MHz. The treated fibers were then immersed in a grafting reaction solution with a bath ratio of 1:20. The reaction solution consisted of 10 wt% mixed monomers (acrylamide and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 4:1.5), 2.0% β-cyclodextrin, 0.8% KH-570 modified nano-silica, and 0.4% ammonium persulfate-sodium bisulfite initiation system (1:1 mass ratio). The pH was adjusted to 5.0 with acetic acid, and the reaction was carried out at a constant temperature of 55 °C for 2.5 h. After the reaction, the fibers were rinsed with hot water at 90 °C, washed with deionized water, and dried at 85 °C for 2.5 h to obtain the modified polyester fibers.

[0054] (4) Select 60D nylon 66 elastic yarn and immerse it in a 3% fatty alcohol polyoxyethylene ether aqueous solution at a bath ratio of 1:30. Soak at a constant temperature of 65℃ for 35 minutes, stirring once every 10 minutes during the soaking. After soaking, wash the fiber repeatedly with deionized water until there is no residual agent on the surface, and then dry it at 75℃ to constant weight to obtain pretreated nylon fiber.

[0055] (5) The modified polyester fiber and the pretreated nylon fiber are thoroughly mixed at a mass ratio of 6:4. An antistatic oil agent (prepared by mixing potassium alkyl phosphate salt and polyoxyethylene castor oil at a mass ratio of 1:1) accounting for 0.8% of the total fiber mass is sprayed evenly onto the mixed fiber and stirred evenly. Then the fiber is fed into the spinning machine and passes through the opening and cleaning, carding, drawing, roving and spinning processes in sequence. The twist of the spinning process is set to 900 twists / meter to obtain the blended yarn.

[0056] (6) The fabric is woven using a double-sided weft knitting circular knitting machine. The blended yarn is used as the ground yarn, and 45D spandex yarn is selected as the elastic yarn. The spandex yarn feed rate is controlled to be 18% of the ground yarn mass. The loom speed is set to 320 r / min, the needle pitch is 13 stitches / inch, the horizontal density is 30 rows / cm, and the vertical density is 28 loops / cm. The woven fabric is placed in a relaxation machine and treated at 85°C for 35 min. Then it is taken out and naturally cooled to room temperature to obtain the four-way stretch fabric.

[0057] Example 4

[0058] A method for preparing a four-way stretch fabric includes the following steps:

[0059] (1) By weight, 100 parts of dimethyl terephthalate, 70 parts of ethylene glycol, 9 parts of polyethylene glycol with a number average molecular weight of 1000, 5 parts of sodium salt of 5-sulfonic acid dimethyl isophthalate and 0.03 parts of zinc acetate catalyst were added to the transesterification vessel. The temperature was raised to 190°C under nitrogen protection and the reaction was maintained for 3.5 h until the methanol distillation reached more than 95% of the theoretical amount. Then, 0.02 parts of trimethyl hydroxyethyl terephthalate crosslinking agent, 0.04 parts of antimony trioxide catalyst and 0.15 parts of triphenyl phosphate heat stabilizer were added to the system. The pre-condensation reaction was carried out at atmospheric pressure and 240°C for 1.5 h. Then, the vacuum was gradually reduced to 50 Pa within 1.5 h and the temperature was raised to 275°C for the final condensation reaction for 4.5 h. The reaction was stopped when the intrinsic viscosity reached 0.68 dL / g. The melt was extruded through an extruder, cooled with cooling water and pelletized to obtain hydrophilic modified polyester chips.

[0060] (2) The hydrophilic modified polyester chips were placed in a vacuum drying oven and dried continuously at 120°C for 10 hours to reduce the moisture content to below 0.02%. Then, they were fed into a melt spinning machine and the spinning temperature was set to 280°C. The melt was extruded through a spinneret with a diameter of 0.25 mm and cooled into filaments by side blowing air at 28°C. The nascent filaments were fed into a drawing machine and subjected to 4.0 times hot drawing at 85°C. Then, they were heat-set at 125°C for 40 seconds to obtain modified polyester nascent fibers.

[0061] (3) Five parts of nano-silica with an average particle size of 20 nm were dispersed in a mixed solution of 150 parts of ethanol and water (volume ratio 4:1). After ultrasonic dispersion for 30 min, 1.5 parts of KH-570 silane coupling agent were added. The pH value was adjusted to 4.5 with glacial acetic acid. The reaction was refluxed at 75 °C for 5 h. After the reaction was completed, the nano-silica was centrifuged, washed three times with ethanol, and dried in a vacuum drying oven at 60 °C to obtain KH-570 modified nano-silica.

[0062] The modified nascent polyester fibers were placed in a plasma treatment instrument, evacuated to 15 Pa, and then a mixture of argon and oxygen in a volume ratio of 3:1 was introduced. The mixture was treated for 4 min at a power of 180 W and a frequency of 13.56 MHz. The treated fibers were then immersed in a grafting reaction solution with a bath ratio of 1:20. The reaction solution consisted of 10 wt% mixed monomers (acrylamide and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 4:2), 2.0% β-cyclodextrin, 1.2% KH-570 modified nano-silica, and 0.4% ammonium persulfate-sodium bisulfite initiation system (1:1 mass ratio). The pH was adjusted to 5.0 with acetic acid, and the reaction was carried out at a constant temperature of 55 °C for 2.5 h. After the reaction, the fibers were rinsed with hot water at 90 °C, then washed with deionized water, and dried at 85 °C for 2.5 h to obtain the modified polyester fibers.

[0063] (4) Select 60D nylon 66 elastic yarn and immerse it in a 4% fatty alcohol polyoxyethylene ether aqueous solution at a bath ratio of 1:30. Soak at 65℃ for 35 minutes, stirring once every 10 minutes. After soaking, wash the fiber repeatedly with deionized water until there is no residual agent on the surface, and then dry it at 75℃ to constant weight to obtain pretreated nylon fiber.

[0064] (5) The modified polyester fiber and the pretreated nylon fiber are thoroughly mixed at a mass ratio of 6:5. An antistatic oil agent (prepared by mixing potassium alkyl phosphate salt and polyoxyethylene castor oil at a mass ratio of 1:1) is sprayed evenly onto the mixed fiber at a mass ratio of 0.8% of the total fiber mass and stirred evenly. Then the fiber is fed into the spinning machine and passes through the opening and cleaning, carding, drawing, roving and spinning processes in sequence. The twist of the spinning process is set to 900 twists / meter to obtain the blended yarn.

[0065] (6) The fabric is woven using a double-sided weft knitting circular knitting machine. The blended yarn is used as the ground yarn, and 45D spandex yarn is selected as the elastic yarn. The spandex yarn feed rate is controlled to be 18% of the ground yarn mass. The loom speed is set to 320 r / min, the needle pitch is 13 stitches / inch, the horizontal density is 30 rows / cm, and the vertical density is 28 loops / cm. The woven fabric is placed in a relaxation machine and treated at 85°C for 35 min. Then it is taken out and naturally cooled to room temperature to obtain the four-way stretch fabric.

[0066] Example 5

[0067] A method for preparing a four-way stretch fabric includes the following steps:

[0068] (1) By weight, 100 parts of dimethyl terephthalate, 50 parts of ethylene glycol, 7 parts of polyethylene glycol with a number average molecular weight of 1000, 3 parts of sodium salt of 5-sulfonic acid dimethyl isophthalate and 0.03 parts of zinc acetate catalyst were added to the transesterification vessel. The temperature was raised to 190°C under nitrogen protection and the reaction was kept at the temperature for 3.5 h until the methanol distillation reached more than 95% of the theoretical amount. Then, 0.02 parts of trimethyl hydroxyethyl terephthalate crosslinking agent, 0.04 parts of antimony trioxide catalyst and 0.15 parts of triphenyl phosphate heat stabilizer were added to the system. The pre-condensation reaction was carried out at atmospheric pressure and 240°C for 1.5 h. Then, the vacuum was gradually reduced to 50 Pa within 1.5 h and the temperature was raised to 275°C for the final condensation reaction for 4.5 h. The reaction was stopped when the intrinsic viscosity reached 0.68 dL / g. The melt was extruded through an extruder, cooled with cooling water and pelletized to obtain hydrophilic modified polyester chips.

[0069] (2) The hydrophilic modified polyester chips were placed in a vacuum drying oven and dried continuously at 120°C for 10 hours to reduce the moisture content to below 0.02%. Then, they were fed into a melt spinning machine and the spinning temperature was set to 280°C. The melt was extruded through a spinneret with a diameter of 0.25 mm and cooled into filaments by side blowing air at 28°C. The nascent filaments were fed into a drawing machine and subjected to 4.0 times hot drawing at 85°C. Then, they were heat-set at 120°C for 30 seconds to obtain modified polyester nascent fibers.

[0070] (3) Five parts of nano-silica with an average particle size of 20 nm were dispersed in a mixed solution of 150 parts of ethanol and water (volume ratio 4:1). After ultrasonic dispersion for 30 min, 1.5 parts of KH-570 silane coupling agent were added. The pH value was adjusted to 4.5 with glacial acetic acid. The reaction was refluxed at 75 °C for 5 h. After the reaction was completed, the nano-silica was centrifuged, washed three times with ethanol, and dried in a vacuum drying oven at 60 °C to obtain KH-570 modified nano-silica.

[0071] The modified nascent polyester fibers were placed in a plasma treatment instrument, evacuated to 15 Pa, and then a mixture of argon and oxygen in a volume ratio of 3:1 was introduced. The mixture was treated for 4 min at a power of 180 W and a frequency of 13.56 MHz. The treated fibers were then immersed in a grafting reaction solution with a bath ratio of 1:20. The reaction solution consisted of 10 wt% mixed monomers (acrylamide and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 4:1), 2.0% β-cyclodextrin, 0.4% KH-570 modified nano-silica, and 0.4% ammonium persulfate-sodium bisulfite initiation system (1:1 mass ratio). The pH was adjusted to 5.0 with acetic acid, and the reaction was carried out at a constant temperature of 55 °C for 2.5 h. After the reaction, the fibers were rinsed with hot water at 90 °C, then washed with deionized water, and dried at 85 °C for 2.5 h to obtain the modified polyester fibers.

[0072] (4) Select 60D nylon 66 elastic yarn and immerse it in a 2% (w / w) fatty alcohol polyoxyethylene ether aqueous solution at a bath ratio of 1:30. Soak at 65°C for 35 minutes, stirring once every 10 minutes. After soaking, wash the fiber repeatedly with deionized water until there is no residual agent on the surface, and then dry it at 75°C to constant weight to obtain pretreated nylon fiber.

[0073] (5) The modified polyester fiber and the pretreated nylon fiber are thoroughly mixed at a mass ratio of 6:3. An antistatic oil agent (prepared by mixing potassium alkyl phosphate salt and polyoxyethylene castor oil at a mass ratio of 1:1) accounting for 0.8% of the total fiber mass is sprayed evenly onto the mixed fiber and stirred evenly. Then the fiber is fed into the spinning machine and passes through the opening and cleaning, carding, drawing, roving and spinning processes in sequence. The twist of the spinning process is set to 900 twists / meter to obtain the blended yarn.

[0074] (6) The fabric is woven using a double-sided weft knitting circular knitting machine. The blended yarn is used as the ground yarn, and 45D spandex yarn is selected as the elastic yarn. The spandex yarn feed rate is controlled to be 18% of the ground yarn mass. The loom speed is set to 320 r / min, the needle pitch is 13 stitches / inch, the horizontal density is 30 rows / cm, and the vertical density is 28 loops / cm. The woven fabric is placed in a relaxation machine and treated at 85°C for 35 min. Then it is taken out and naturally cooled to room temperature to obtain the four-way stretch fabric.

[0075] Comparative Example 1: The difference between Comparative Example 1 and Example 4 is that step 1 is omitted, and the hydrophilic modified polyester chips in step 2 are replaced with unmodified ordinary polyester chips. That is, the polyester fibers are not hydrophilic modified by polyethylene glycol and sodium dimethyl isophthalate 5-sulfonic acid salt, nor are they crosslinked.

[0076] Comparative Example 2: The difference between Comparative Example 2 and Example 4 is that step 3 is omitted, and the modified polyester fiber in step 5 is replaced with modified polyester nascent fiber, that is, the P(AM-co-AMPS) hydrophilic copolymer graft layer is not bonded to the surface of the polyester fiber.

[0077] Comparative Example 3: The difference between Comparative Example 3 and Example 4 is that in step 3, β-cyclodextrin and KH-570 modified nano-silica are not added to the reaction solution.

[0078] Performance testing:

[0079] 1. Moisture Absorption Rate Test: Referring to GB / T 21655.1-2008 "Evaluation of Moisture Absorption and Quick-Drying Properties of Textiles - Part 1: Single-Item Combination Test Method", fabric samples with a size of 10cm × 10cm were selected and equilibrated for 24 hours at a temperature of 20±2℃ and a relative humidity of 65±4%. The dry weight (m0) was then measured. Subsequently, the samples were completely immersed in distilled water (20±2℃) for 30 minutes. After soaking, the samples were removed, and the surface water was blotted dry with filter paper. The wet weight (m1) was immediately measured. The moisture absorption rate was calculated using the formula: Moisture Absorption Rate (%) = (m1 - m0) / m0 × 100%. Each group of samples was tested three times, and the average value was taken. The test results are shown in Table 1.

[0080] 2. Moisture permeability test: Referencing GB / T 12704.1-2021 "Textiles - Determination of moisture permeability - Part 1: Moisture absorption method", the sample size was 18cm × 18cm. Test conditions were set as follows: temperature 38±2℃, relative humidity 90±2%, and test time 24h. The moisture permeability per unit area over 24h was calculated, with units of g / (m²). 2 • 24h), each group of samples was tested 3 times, and the average value was taken. The test results are shown in Table 1.

[0081] 3. Moisture Absorption Rate Test: Referring to FZ / T 01071-2008 "Test Method for Capillary Effect of Textiles", the test method was modified. Three warp and three weft samples of the fabric were selected, each measuring 2cm × 30cm. One end (2cm length) of the sample was immersed in distilled water (20±2℃), and the height (cm) of water rising along the sample within 10 minutes was recorded. The average value of the warp and weft directions was used as the evaluation index of moisture absorption rate; the higher the value, the faster the moisture absorption rate. The test results are shown in Table 1.

[0082] 4. Elastic recovery rate test: Referring to GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)", the constant elongation method was used. Three warp and three weft samples were selected, each with a size of 5cm × 20cm. After stretching to 15% elongation, the sample was held for 30s, released, and allowed to stand for 30s. The length of the recovered sample was then measured. The elastic recovery rate was calculated using the formula: Elastic recovery rate (%) = (Length before stretching - Length after recovery) / (Length before stretching - Original length) × 100%, and the average value of the warp and weft samples was taken. The test results are shown in Table 1.

[0083] 5. Test on retention rate of hydrophilicity after washing: Referring to GB / T 8629-2017 "Home washing and drying procedures for textile testing", the 5A washing program (water temperature 40±3℃, washing time 30min, liquor ratio 1:30) was used. The samples were washed 50 times and then dried. The moisture absorption rate after washing was determined according to the above moisture absorption rate test method. The retention rate was calculated using the formula: Retention rate (%) = (Moisture absorption rate after washing / Moisture absorption rate before washing) × 100%. The test results are shown in Table 1.

[0084] Table 1:

[0085] Moisture absorption rate (%) <![CDATA[Water vapor transmission rate (g / (m 2 •24h))]]> Moisture absorption rise height (cm) in 10 minutes Moisture retention rate after 50 washes (%) Elastic recovery rate (%) Example 1 17.5 8423 8.9 87.9 92.1 Example 2 15.7 7986 7.8 85.7 91.8 Example 3 16.3 8152 8.2 86.4 92.5 Example 4 18.2 8649 9.3 88.5 92.3 Example 5 15.2 7817 7.5 84.3 91.5 Comparative Example 1 5.3 4276 3.1 62.5 90.8 Comparative Example 2 10.1 6349 4.5 70.3 91.2 Comparative Example 3 14.5 7561 6.2 72.4 92.0

[0086] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 four-way stretch fabric, characterized in that, Includes the following steps: (1) Dimethyl terephthalate, ethylene glycol, polyethylene glycol, sodium salt of 5-sulfonic acid dimethyl isophthalate and zinc acetate catalyst are mixed and heated under inert gas protection. Then, trimethyl hydroxyethyl terephthalate crosslinking agent, antimony trioxide catalyst and triphenyl phosphate heat stabilizer are added. First, pre-condensation is carried out at normal pressure, and then vacuum heating is carried out for final condensation. After the reaction is completed, hydrophilic modified polyester chips are obtained by extrusion, cooling and pelletizing. (2) After drying the hydrophilic modified polyester chips, melt spinning was performed, followed by cooling, hot stretching and heat setting to obtain nascent fibers; (3) The nascent fiber was subjected to plasma treatment, and then the nascent fiber was immersed in a reaction solution containing acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, β-cyclodextrin, KH-570 modified nano silica and ammonium persulfate-sodium bisulfite initiation system for constant temperature reaction. After the reaction, it was rinsed with hot water, washed and dried to obtain modified polyester fiber. (4) Immerse the nylon fiber in a fatty alcohol polyoxyethylene ether aqueous solution at a constant temperature, then wash it with deionized water and dry it to obtain pretreated nylon fiber. (5) The modified polyester fiber is mixed with the pretreated nylon fiber, and after spraying with antistatic oil, it is processed through opening and cleaning, carding, drawing, roving and spinning processes to obtain the blended yarn. (6) Using a double-sided weft knitting circular knitting machine, the blended yarn is used as the ground yarn and spandex yarn is used as the elastic yarn for knitting. After knitting into a greige fabric, it is subjected to relaxation heat treatment and cooling to obtain a four-way stretch fabric.

2. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (1), the mass ratio of dimethyl terephthalate to ethylene glycol is 10:(5-7).

3. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (1), the mass ratio of dimethyl terephthalate to polyethylene glycol is 10:(0.7-0.9).

4. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (1), the mass ratio of dimethyl terephthalate to sodium 5-sulfonic acid dimethyl isophthalate is 10:(0.3-0.5).

5. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (2), the heat setting temperature is 120-125℃ and the heat setting time is 30-40s.

6. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (3), the mass ratio of acrylamide to 2-acrylamide-2-methylpropanesulfonic acid is 4:(1-2).

7. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (3), the mass ratio of β-cyclodextrin to KH-570 modified nano-silica is 5:(1-3).

8. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (4), the concentration of the fatty alcohol polyoxyethylene ether aqueous solution is 2-4 wt%.

9. The method for preparing a four-way stretch fabric according to claim 1, characterized in that, In step (5), the mass ratio of modified polyester fiber to pretreated nylon fiber is 6:(3-5).

10. A four-way stretch fabric, characterized in that, It is prepared by the method described in any one of claims 1 to 9 above.

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