Spandex-free elastic woven fabric and preparation method thereof

Abstract

The invention discloses a spandex-free elastic woven fabric and a preparation method thereof.The preparation method comprises the steps that on a material layer, graphene / nano-silicon dioxide modified PBT / PTT composite fibers are adopted as warp yarn, and a spring-damping elastic structure is constructed; the surface warp yarns are made of carbon nano tube coated superfine denier chinlon, so that the surface friction is reduced; the weft yarns are Yacell / PTT (polytrimethylene terephthalate) double-component core-spun yarns, so that the transverse elasticity and the moisture absorption and conduction functions are coordinated; in the process level, precise weaving is achieved through an AI tension control system and a magnetic suspension weft insertion technology, and the stress distribution of the fabric better conforms to the human motion law in combination with a digital twinning optimization bionic sine wave structure; the fiber damage is avoided by adopting a supercritical CO2 anhydrous dyeing and finishing technology; and finally, the conductivity and the wear resistance are improved through graphene nanosheet padding treatment. According to the invention, integration of high elasticity, high durability and intelligent response is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of woven fabrics and weaving methods, and particularly to woven fabrics characterized by the yarns or other warp and weft materials or structures used, specifically a non - spandex elastic woven fabric and its preparation method. Background Art

[0002] Traditional elastic fabrics mainly rely on spandex (polyurethane fiber) to provide elasticity. Although spandex has excellent elongation and resilience, its inherent defects are becoming increasingly prominent. Spandex is prone to aging and breaking during long - term use, and it is difficult to dye, resulting in limited color selection. In addition, the production cost of spandex is relatively high, and recycling is difficult, which does not conform to the trend of sustainable development. Especially in application scenarios such as swimwear and sportswear that frequently contact chlorine or sweat, the chlorine resistance and chemical resistance of spandex are poor, which easily leads to a decline in fabric performance. Therefore, there is an urgent need in the market for a new type of woven fabric that does not rely on spandex but can provide excellent elasticity and durability. In recent years, the research on non - spandex elastic fabrics has gradually become a hot topic, mainly achieving elastic functions through fiber modification, yarn structure design, and fabric tissue optimization.

[0003] In the prior art, non - spandex elastic woven fabrics mainly achieve elasticity through high - elastic fibers (such as PBT, PTT) or core - spun yarn structures, but these methods have obvious limitations. For example, the elastic performance of a single high - elastic fiber is limited and it is prone to fatigue due to repeated stretching; although core - spun yarns can improve elasticity, the process is complex and the cost is high. In addition, traditional weaving techniques are difficult to precisely control yarn tension, resulting in uneven fabric elasticity and affecting wearing comfort. There are also problems in the dyeing and finishing process. The dye uptake rate of conventional dyeing processes for high - elastic fibers is low, and the color fastness is poor, while high - temperature treatment may damage the elastic properties of the fibers. The fabrics in the prior art are prone to elastic attenuation after multiple washes and lack intelligent response functions, unable to meet the requirements of high - end application scenarios.

[0004] Therefore, it is necessary to improve the non - spandex elastic woven fabric and its preparation method in the prior art to solve the above problems. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a non - spandex elastic woven fabric and its preparation method, aiming to solve the problems of insufficient elasticity of single fibers, low precision of weaving processes, large damage during dyeing and finishing, and single function in the prior art.

[0006] To achieve the above object, the technical solution adopted by the present invention is: A preparation method of a non - spandex elastic woven fabric, comprising: S1. Prepare warp yarns, face warp yarns and weft yarns. Among them, the warp yarns are prepared by blending and modifying PBT / PTT fibers with graphene and nano-silica, and blending with shape memory polymer staple fibers; the face warp yarns are prepared by superfine polyamide fibers coated with carbon nanotubes on the surface; the weft yarns are prepared by Yasser and PTT bicomponent core-spun yarns; S2. Pretreat the warp yarns and weft yarns. Among them, the warp yarns are activated, and the weft yarns are degreased; S3. Perform intelligent weaving on the warp yarns and weft yarns to form a base fabric with a bionic sine wave joint structure. Among them, the bionic sine wave joint structure is a continuous curvature joint path that simulates the bending curvature and movement stress distribution of human joints; S4. Perform supercritical CO2 dyeing and finishing on the base fabric; S5. Treat the dyed fabric by dipping and rolling with graphene nanosheets to obtain an elastic woven fabric without spandex.

[0007] In a preferred embodiment of the present invention, the preparation of the warp yarns in step S1 includes the following sub-steps: Blend and melt PBT / PTT chips with graphene masterbatch and nano-silica, and extrude through a twin-screw spinning machine to form composite filaments; among them, the mass ratio of PBT to PTT is 1-1.3:1, the sheet diameter of the graphene masterbatch is 50-100nm and the proportion is 0.3-0.5%, the particle size of nano-silica is 20-30nm and the proportion is 0.1-0.3%, the melting temperature of PBT / PTT chips is 260-270°C, the mixing time is 15-20min, and the rotation speed is 300-400rpm; the screw diameter of the twin-screw spinning machine is Φ45mm, the length-diameter ratio L / D = 32:1, the aperture of the spinning nozzle is 0.2-0.25mm, and the number of holes in the spinneret is 24-36; Blend the composite filaments with shape memory polymer staple fibers through a drawing frame to form a blended yarn; among them, the length of SMP is 38-51mm and accounts for 10% of the total amount of warp yarns, the number of drawn strands is 6-8, the roller gauge is 32-35mm, and the delivery speed is 40-45m / min; Perform multi-stage drafting on the blended yarn to obtain modified composite warp yarns; among them, the primary drafting temperature is 80-85°C, and the drafting ratio is 3.5-3.7:1; the secondary drafting temperature is 120-125°C, and the drafting ratio is 1.2-1.5:1; the winding speed is 3500-3800m / min.

[0008] In a preferred embodiment of the present invention, the preparation of the face warp yarns in step S1 includes the following sub-steps: Select ultrafine denier polyamide filament as the base material, and remove the surface sizing agent through pretreatment with 5% NaOH solution; among them, the denier of the ultrafine denier polyamide filament is 0.4 - 0.6D, the single filament diameter is 10 - 20μm, the pretreatment temperature is 60°C, and the treatment time is 10min; Under the protection of argon, carbon nanotubes are uniformly loaded on the surface of polyamide fiber by chemical vapor deposition to form a functional coating; among them, the argon flow rate is 400 - 500 sccm, the carbon source is methane and the flow rate is 80 - 100 sccm, the reaction temperature is 600 - 650°C, and the coating time is 10 - 15min; the diameter of the quartz tube of the chemical vapor deposition device is Φ80 - 100mm, and the length of the heating zone is 250 - 300mm; the diameter of the carbon nanotubes is 10 - 20nm, the purity ≥95%, and the loading amount is 0.1 - 0.15%.

[0009] In a preferred embodiment of the present invention, the preparation of the weft yarn in step S1 includes the following sub - steps: Using PTT staple fiber as the core layer, and selecting Yaser staple fiber with a groove structure for the outer layer. The Yaser staple fiber is uniformly coated on the surface of the PTT core yarn by a ring spinning frame to form a two - component core - spun yarn; among them, the lengths of both the PTT staple fiber and the Yaser staple fiber are 35 - 40mm, and the mass ratio of PTT to Yaser is 1:2.2 - 2.4; the spindle speed of the ring spinning frame is 15000 - 16000rpm, the tension of the PTT core yarn is 3 - 5cN, the draft multiple of the back zone is 1.2 - 1.3 times, and the twist is 101.3 - 105.6 turns / 10cm.

[0010] In a preferred embodiment of the present invention, the activation treatment of the warp yarn in step S2 adopts the atmospheric pressure low - temperature plasma technology with argon - oxygen mixed gas as the medium; among them, the volume ratio of argon to oxygen is 3 - 3.5:1, and the total flow rate is 200 - 300 sccm; it is processed by a radio - frequency power supply, the frequency is 13 - 14MHz, the power is 400 - 500W, and the treatment time is 20 - 30s; after treatment, nano - scale micropores with a pore diameter of 50 - 100nm are etched on the fiber surface, and hydroxyl and carboxyl active groups are introduced.

[0011] In a preferred embodiment of the present invention, the impurity removal treatment of the weft yarn in step S2 adopts a compound system of cellulase and pectinase; among them, the mass ratio of cellulase to pectinase is 2 - 2.5:1, and the total concentration is 20 - 25g / L; it is processed under ultrasonic assistance, the ultrasonic frequency is 40kHz, and the power is 300 - 400W; the treatment conditions are: temperature 45 - 50°C, time 30 - 40min, pH value 5.5 - 6.0, and the mass ratio of the yarn to the solution is 1:20 - 23.

[0012] In a preferred embodiment of the present invention, the specific parameters of the intelligent weaving in step S3 include: The AI tension control system uses an optical fiber tension sensor with an accuracy of ±0.1 N and a sampling frequency of 80 - 2100 Hz. It adjusts the speed of the warp feeding motor based on the LSTM dynamic tension prediction model to ensure that the warp tension fluctuation range is ≤ ±0.3 N. Among them, the warp tension is 12 - 15 N, and the surface warp tension is 8 - 10 N. The electromagnetic levitation multi - shed weft insertion uses an electromagnetic levitation guide rail with a levitation height of 0.5 - 1 mm, a magnetic field strength of 0.1 - 0.2 T, a weft insertion speed of 800 - 1000 m / min, and a weft density of 420 - 450 picks per 10 cm. The bionic sine wave structure parameters optimized by the digital twin model are: the radius of curvature is 8 - 12 mm, the angle gradient is 38° - 42°, increasing from the center to the edge of the fabric, the spacing of the binding warp is 2 - 3 mm, and the space coordinate expression is , where is the amplitude, 2 - 3 mm, is the wavelength, 8 - 10 mm, is the phase difference, 15° - 20°.

[0013] In a preferred embodiment of the present invention, the parameters of supercritical CO2 dyeing and finishing in step S4 are: the CO2 temperature is 80 - 100 °C, the pressure is 15 - 20 MPa, the dosage of disperse dye is 2 - 3%, the circulation time is 60 - 80 min, and the pressure relief rate is 0.5 - 1 MPa / min.

[0014] In a preferred embodiment of the present invention, the parameters of the dip - rolling treatment of graphene nanosheets in step S5 are: the diameter of the graphene nanosheets is 50 - 100 nm, and the concentration is 1 - 2 g / L; the dispersant is sodium dodecylbenzenesulfonate with a concentration of 0.5 - 1 g / L, and the Zeta potential is ≥ - 30 mV; the binder is aqueous polyurethane with a concentration of 3 - 5 g / L; the suspension is prepared by ultrasonic dispersion with a frequency of 40 kHz, a power of 500 W, and a time of 20 - 30 min; the dip - rolling temperature is 25 ± 2 °C, the liquor ratio is 60 - 70%, and the nip pressure of the padding mangle is 0.3 - 0.5 MPa; the pre - drying temperature is 80 - 90 °C, the time is 3 - 5 min, and the curing temperature is 120 - 130 °C, the time is 2 - 3 min.

[0015] The present invention provides an ammonia - free spandex elastic woven fabric: the fabric is jointly composed of warp, surface warp, and weft. Among them, the warp is the longitudinal elastic support layer, the surface warp is the surface functional layer, and the weft is the transverse moisture - absorbing elastic layer; the fabric has a bionic sine wave binding structure with a sine wave radius of curvature of 8 - 12 mm, an angle gradient of 38° - 42°, increasing from the center to the edge, and the spacing of the binding warp is 2 - 3 mm; high color fastness is achieved through supercritical CO2 dyeing and finishing, and temperature - sensitive active elastic recovery is imparted through thermosensitive memory finishing, with a triggering temperature of 37 ± 2 °C, and the antistatic and friction - resistant properties are improved through the loading of graphene nanosheets.

[0016] The present invention solves the defects existing in the background art and has the following beneficial effects: (1) The present invention provides a spandex-free elastic woven fabric and a preparation method thereof. Through the collaborative innovation of multi-scale material composite and intelligent process, it solves the technical bottlenecks such as insufficient elasticity, poor durability, and low comfort of traditional spandex-free elastic fabrics. At the material level, graphene / nano-silica modified PBT / PTT composite fiber is used as the warp yarn to construct a "spring-damping" elastic structure; the surface warp yarn is selected as carbon nanotube-coated superfine denier polyamide fiber to reduce surface friction; the weft yarn adopts Yaser / PTT bicomponent core-spun yarn to realize the synergy of lateral elasticity and moisture absorption and moisture conduction functions. At the process level, precise weaving is realized through the AI tension control system and the magnetic levitation weft insertion technology. Combining digital twin to optimize the bionic sine wave structure makes the stress distribution of the fabric more in line with the human body movement law. The supercritical CO2 anhydrous dyeing and finishing technology is adopted to avoid fiber damage, and the temperature-sensitive memory finishing is combined to endow the fabric with a body temperature-triggered self-recovery function. Finally, the graphene nanosheet padding treatment is used to improve the conductivity and wear resistance; an integrated breakthrough of high elasticity, high durability, and intelligent response is achieved.

[0017] (2) By using graphene / nano-silica modified PBT / PTT composite fiber as the warp yarn, combining carbon nanotube-coated polyamide surface warp yarn and Yaser / PTT bicomponent core-spun weft yarn, the present invention constructs a multi-level elastic network system. The multi-scale material composite design enables different fiber components to form complementary synergy in terms of elasticity, strength, and functional characteristics: the modified PBT / PTT fiber provides the original elasticity through the "spring-damping" structure induced by graphene, and nano-silica enhances the interfacial bonding force; the carbon nanotube coating layer reduces the surface friction coefficient, while the PTT core layer of the core-spun weft yarn and the Yaser groove structure contribute to the lateral elasticity and moisture absorption and moisture conduction functions respectively.

[0018] (3) The present invention introduces an intelligent weaving process that combines the AI tension control system and the magnetic levitation weft insertion technology. By real-time monitoring and dynamically adjusting the warp yarn tension, and cooperating with non-contact high-speed weft insertion, precise positioning and structure control of the yarn are achieved. The AI system responds to the multi-warp shaft tension at the millisecond level based on the LSTM algorithm to ensure that the warp yarn tension of each layer is stable in the optimal range during the weaving process; the magnetic levitation technology drives the weft inserter with electromagnetic force, avoiding the yarn wear caused by traditional mechanical weft insertion. Compared with the problems of yarn displacement or breakage caused by uneven tension in traditional weaving technology, this process improves the uniformity of fabric density, and the weft yarn density can reach 450 pieces / 10 cm. Combining the bionic sine wave joint structure optimized by digital twin technology makes the stress distribution of the fabric closer to the human skin deformation law during dynamic stretching.

[0019] (4) The supercritical CO2 dyeing and finishing process adopted by the present invention solves the problem of damage to elastic fibers in traditional dyeing and finishing technologies. The supercritical CO2 fluid directly transports dyes to the amorphous region of fibers without the need for an aqueous medium, avoiding the molecular chain breakage caused by high-temperature and high-pressure water dyeing. Compared with the existing dyeing and finishing processes, this technology improves the dyeing uniformity and reduces the fiber strength loss at the same time.

[0020] (5) The present invention constructs a three-dimensional conductive network on the surface layer of the fabric treated by dip-rolling with graphene nanosheets, solving the problems of poor antistatic performance and easy surface wear of traditional elastic fabrics; the graphene nanosheets form a continuous protective layer on the fiber surface through an aqueous polyurethane binder, not only reducing the surface resistance of the fabric to achieve an antistatic effect, but also significantly improving the sliding property between fibers with its two-dimensional structure. The graphene layer and the bottom carbon nanotube-coated surface warp form a synergistic conductive path, enabling the fabric to have preliminary strain sensing ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings; Figure 1 It is a flowchart of a preferred embodiment of the present invention; Figure 2 It is a flowchart of an intelligent weaving control system of a preferred embodiment of the present invention; Figure 3 It is a functional synergy diagram of a preferred embodiment of the present invention; Figure 4 It is a fabric composition diagram of a preferred embodiment of the present invention; Figure 5 It is a fabric structure diagram of a preferred embodiment of the present invention; In the figure: 1, surface warp; 2, warp; 3, binding warp; 4, weft. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0024] Overview of the Application: The technical bottlenecks of existing non - spandex elastic fabrics mainly stem from the lack of coordination between material selection and process design. From the material perspective, single fibers are difficult to simultaneously meet the requirements of elasticity, strength, and durability, and the interfacial compatibility problems of composite fibers will affect the performance stability. From the process perspective, traditional weaving techniques cannot achieve precise control of yarns, resulting in a low elastic recovery rate; the high - temperature and high - pressure environment of the dyeing and finishing process is likely to damage the molecular structure of elastic fibers, exacerbating performance degradation. In addition, existing technologies lack the ability to regulate the microscopic deformation mechanism of fibers, cannot achieve bionic elasticity through structural design, and ignore the potential of intelligent materials in dynamic response.

[0025] As Figure 3 shown, this application proposes a non - spandex elastic woven fabric and its preparation method, which solves the above problems through multi - scale material composite and intelligent process coordination. At the material level, graphene / nano - silica - modified PBT / PTT fibers are used as warp yarns, combined with carbon nanotube - coated polyamide and bicomponent core - spun weft yarns to construct a multi - level elastic network; at the process level, AI tension control and magnetic levitation weft insertion technologies are introduced to achieve precise weaving of yarns, and the bionic structure is optimized through digital twin. The supercritical CO2 dyeing and finishing technology avoids the defects of traditional processes, and the graphene nanoplatelet padding treatment further improves the conductivity and durability of the fabric.

[0026] Exemplary Method: As Figure 1 shown, a method for preparing a non - spandex elastic woven fabric includes the steps of: S1. Prepare warp yarns, surface warp yarns, and weft yarns. Among them, the warp yarns are prepared by blending graphene and nano - silica to modify PBT / PTT fibers and mixing with shape - memory polymer staple fibers; the surface warp yarns are prepared by super - fine denier polyamide coated with carbon nanotubes; the weft yarns are prepared by Yaser and PTT bicomponent core - spun yarns; S2. Pretreat the warp yarns and weft yarns. Among them, the warp yarns are activated, and the weft yarns are degreased; S3. Intelligently weave the warp yarns and weft yarns to form a basic fabric with a bionic sine - wave joint structure. The bionic sine - wave joint structure is a continuous curvature joint path that simulates the bending curvature and movement stress distribution of human joints; the intelligent weaving dynamically adjusts the warp yarn tension through an AI tension control system, simultaneously increases the weft yarn density by using magnetic levitation multi - shed weft insertion, and then optimizes the joint warp yarn path based on a digital twin model to form a bionic sine - wave structure; S4. Supercritical CO2 dyeing and finishing of the base fabric; S5. Dip-rolling the dyed fabric with graphene nanosheets to obtain an elastic woven fabric without spandex.

[0027] As Figure 4 shown, the warp yarns are arranged along the longitudinal direction of the fabric, i.e., the length direction, and mainly undertake the structural support and longitudinal elastic functions of the fabric; the surface warp yarns are the warp yarns located on the surface layer of the fabric, responsible for the surface touch, anti-friction property and appearance density; the weft yarns are arranged along the transverse direction of the fabric, i.e., the width direction, and dominate the transverse elasticity, moisture absorption comfort and structural filling functions. In this application, an intelligent weaving process is used to achieve the co-weaving of the three-layer structure.

[0028] In step S1, the preparation of the warp yarns includes: Blending and melting PBT / PTT chips with graphene masterbatch and nano-silica, and extruding through a twin-screw spinning machine to form composite filaments; Blending the composite filaments with shape memory polymer staple fibers through a drawing frame to form blended yarns; Performing multi-stage drawing treatment on the blended yarns to optimize the fiber crystallinity and orientation degree, and finally obtaining modified composite warp yarns with uniform diameter.

[0029] Among them, PBT is polybutylene terephthalate, PTT is polytrimethylene terephthalate, and the mass ratio is 1 - 1.3:1; The sheet diameter of the graphene masterbatch is 50 - 100 nm, and the proportion is 0.3 - 0.5%, the particle size of the nano-silica is 20 - 30 nm, and the proportion is 0.1 - 0.3%; The shape memory polymer staple fiber is SMP, with a length of 38 - 51 mm, accounting for 10% of the total amount of the warp yarns; The PBT / PTT chips are melted at 260 - 270 °C; the graphene masterbatch, nano-silica and molten PBT / PTT are fully mixed, the mixing time is 15 - 20 min, and the rotation speed is 300 - 400 rpm; graphene induces the molecular chains to form a "spring-damping" biphasic structure, and nano-silica enhances the surface roughness of the fibers; The screw diameter of the twin-screw spinning machine is Φ45 mm, the length-diameter ratio L / D = 32:1, the aperture of the spinning nozzle is 0.2 - 0.25 mm, the number of holes in the spinneret plate is 24 - 36 holes, and the composite filaments are output; Blending the modified PBT / PTT filaments with SMP staple fibers through a drawing frame, the doubling number is 6 - 8 roots, the roller gauge is 32 - 35 mm, and the delivery speed is 40 - 45 m / min to form warp yarns with both elastic recovery and rapid recovery characteristics; The drawing treatment includes: The primary draft temperature is 80 - 85°C, and the draft ratio is 3.5 - 3.7:1; the secondary draft temperature is 120 - 125°C, and the draft ratio is 1.2 - 1.5:1; the winding speed is 3500 - 3800 m / min to obtain the modified PBT / PTT composite fiber; The warp yarn serves as the core of the elastic support layer, providing longitudinal elasticity and structural support, and enhancing the elastic origin through the composite modified fiber.

[0030] In step S1, the preparation of the surface warp yarn includes: Select ultrafine denier polyamide filament as the base material, and remove the surface sizing agent through alkali liquor pretreatment; Under the protection of argon, use chemical vapor deposition to uniformly load carbon nanotubes on the surface of polyamide fiber to form a functional coating; Among them, the denier of the ultrafine denier polyamide filament is 0.4 - 0.6 D, and the single filament diameter is 10 - 20 μm; the carbon nanotube diameter is 10 - 20 nm, the purity is ≥95%, and the dispersant uses sodium dodecyl sulfate with a concentration of 0.5 - 0.6%; the alkali liquor is 5% NaOH solution; the ultrafine denier structure enhances the surface coverage, and the fabric surface is smoother; Use a chemical vapor deposition device, the diameter of the quartz tube is Φ80 - 100 mm, and the length of the heating zone is 250 - 300 mm; The ultrafine denier polyamide filament is treated in 5% NaOH solution at 60°C for 10 min to remove the surface sizing agent; The argon flow rate is 400 - 500 sccm, the carbon source is methane CH4, and the flow rate is 80 - 100 sccm; the reaction temperature is 600 - 650°C to avoid high-temperature degradation of polyamide, the coating time is 10 - 15 min, and the carbon nanotube loading is 0.1 - 0.15%. The carbon nanotubes reduce the surface friction coefficient of the fiber and improve the tensile flexibility.

[0031] The surface warp yarn serves as the surface functional layer to improve the surface anti-friction property, tensile flexibility and compactness.

[0032] In step S1, the preparation of the weft yarn includes: Use PTT staple fiber as the core layer to provide basic elasticity, and select Yasser staple fiber with a groove structure for the outer layer to enhance the moisture absorption and moisture conduction performance; use a ring spinning frame to center the PTT core yarn, and use drafting rollers to uniformly wrap the Yasser staple fiber on the surface of the core yarn to form a tight core-spun structure; the PTT core layer endows the weft yarn with transverse elasticity, and the Yasser outer layer quickly conducts moisture through the groove structure. At the same time, the core-spun structure reduces fiber friction damage and improves fatigue resistance.

[0033] Among them, the length of PTT staple fiber is 35 - 40 mm, the Yaser staple fiber has a grooved structure, with a length of 35 - 40 mm and a mass ratio of 1:2.2 - 2.4; the spindle speed of the ring spinning frame is 15000 - 16000 rpm, the tension of the PTT core yarn is 3 - 5 cN, and the Yaser staple fiber uniformly wraps the core yarn through the drafting rollers. The back zone drafting is 1.2 - 1.3 times, and the twist is 101.3 - 105.6 turns / 10 cm to ensure the tightness of the wrapping. The PTT core layer provides lateral basic elasticity, and the grooved structure of the Yaser outer layer enhances the moisture absorption and moisture conduction performance. The core-spun structure avoids the direct exposure of PTT and reduces frictional damage.

[0034] The weft yarn serves as the moisture-absorbing elastic layer, providing lateral elasticity and moisture absorption and moisture conduction performance, and enhancing wearing comfort.

[0035] Step S1 realizes the differential function coordination of the warp yarn, the surface warp yarn, and the weft yarn through the triple design of modified fibers, functional coatings, and core-spun structures, laying the foundation for the high elasticity and comfort of the spandex-free elastic fabric.

[0036] In step S2, the warp yarn improves the bonding force between the warp yarn and the finishing agent through surface activation, reduces the breakage of the warp yarn during weaving, and optimizes the surface polarity of the fiber to enhance the penetration effect of subsequent functional finishing. Using the atmospheric pressure low-temperature plasma technology, with the argon-oxygen mixed gas as the medium, the surface of the mixed warp yarn of modified PBT / PTT composite fiber and superfine polyamide fiber is bombarded by high-energy particles; the plasma etches nano-scale micropores on the fiber surface, and at the same time introduces active groups such as hydroxyl (-OH) and carboxyl (-COOH), improving the surface polarity of the fiber.

[0037] Among them, through the treatment of the atmospheric pressure low-temperature plasma generator, a radio frequency power supply is used, with a frequency of 13 - 14 MHz; the mixed gas of argon and oxygen, with a volume ratio of 3 - 3.5:1 and a total flow rate of 200 - 300 sccm; the treatment parameters: the power is 400 - 500 W to avoid damaging the fiber structure at high power, and the time is 20 - 30 s to complete the surface etching and group introduction in a short time.

[0038] The high-energy particles in the plasma bombard the fiber surface, etching out nano-scale micropores with a pore diameter of 50 - 100 nm, and at the same time dissociating Ar / O2 into active groups and grafting them onto the fiber surface; the surface polarity of the fiber increases, the contact angle decreases, and the wettability improves.

[0039] In step S2, the weft yarn removes the impurities on the surface of the weft yarn, such as the pectin and hemicellulose of the Yaser fiber and the spinning oil agent of the PTT fiber, to avoid the formation of lint balls or clogging of the yarn guide during weaving, and at the same time improve the uniform penetration of dyes in the subsequent dyeing and finishing processes.

[0040] A cellulose enzyme and pectin enzyme complex system is used to perform surface hydrolysis on the Yaser / PTT core-spun yarn, removing the pectin and amorphous cellulose on the outer layer of the Yaser fiber while avoiding damage to the PTT core layer structure; ultrasonic oscillation is introduced during the enzymatic hydrolysis process, and through the cavitation effect, the enzyme molecules are accelerated to penetrate into the fiber interior, stripping the decomposed impurity particles and preventing re-deposition.

[0041] Among them, the composite bio-enzyme is cellulose enzyme and pectin enzyme, with a mass ratio of 2 - 2.5:1 and a total concentration of 20 - 25 g / L; the ultrasonic frequency is 40 kHz, and the power is 300 - 400 W, enhancing the diffusion of enzyme molecules and fiber penetration; the treatment conditions are: the temperature is 45 - 50 °C, the time is 30 - 40 min, the pH value is 5.5 - 6.0, and the mass ratio of the yarn to the solution is 1:20 - 23; the cellulose enzyme selectively hydrolyzes the amorphous cellulose on the surface of the Yaser fiber, and the pectin enzyme decomposes the pectin in the Yaser fiber, reducing the adhesion between fibers; the ultrasonic cavitation effect generates micro-jet flow, accelerating the penetration of enzyme molecules into the fiber interior and simultaneously stripping the decomposed impurities.

[0042] As Figure 2 shown, in step S3, the intelligent weaving realizes the precise positioning of the yarn and the construction of the bionic elastic structure through the coordinated operation of three major technologies: AI tension dynamic regulation, magnetic levitation multi-shed weft insertion, and digital twin model optimization of the knotting path, solving the problems of inaccurate yarn regulation and low elastic recovery rate in traditional weaving technology; The tension dynamic regulation ensures uniform tension of each layer of warp yarn during weaving by real-time monitoring and adjusting the tension of different types of warp yarns, avoiding structural deformation or elastic loss caused by tension fluctuations; The AI multi-beam warp let-off device integrates an optical fiber tension sensor with an accuracy of ±0.1 N, a dynamic tension prediction model based on LSTM, inputs real-time tension data with a sampling frequency of 80 - 2100 Hz, and outputs the instruction for adjusting the rotational speed of the let-off motor to ensure that the tension fluctuation range ≤ ±0.3 N; The warp yarn bears the longitudinal elasticity and structural support, with a tension of 12 - 15 N; The surface warp yarn is the surface functional layer, with a tension of 8 - 10 N, avoiding excessive stretching that affects the surface smoothness.

[0043] The magnetic levitation multi-shed weft insertion technology reduces the wear of the weft yarn through contactless weft insertion, improves the weft yarn density, and enhances the transverse elasticity and structural compactness; The magnetic levitation multi-shed loom uses an electromagnetic suspension guide rail with a suspension height of 0.5 - 1 mm, a weft insertion speed of 800 - 1000 m / min, a weft yarn density of 420 - 450 pieces / 10 cm, and a suspension magnetic field intensity of 0.1 - 0.2 T.

[0044] The magnetic levitation weft inserter moves in suspension through electromagnetic force, has no mechanical contact with the yarn guide, and reduces the wear rate of the weft yarn.

[0045] As Figure 5 shown, the digital twin model optimizes the path of the binder warp based on fiber deformation simulation, forming a bionic sine wave structure to enhance the dynamic elastic adaptability of the fabric; the binder warp is a special warp system, and its core function is to penetrate multiple layers of fabric through a specific path and physically connect the separated yarn layers, the surface warp layer, the weft layer, and the bottom warp into a whole. In the bionic sine wave structure of this application, the binder warp is a key technical element for constructing a three-dimensional elastic network, and the material is the same as the warp; The binder warp of this application penetrates three layers in a wavy line of a sine wave path to achieve three-layer dynamic coupling, including: The radius of curvature of the sine wave is 8-12 mm, simulating the curvature when the human joint bends; The angle gradient is 38°-42°, increasing from the center of the fabric to the edge, matching the stress distribution during human movement; The spacing of the binder warp is 2-3 mm to ensure uniform distribution of elastic support points; The spatial coordinates of the binding path are expressed as , where is the amplitude, 2-3 mm, corresponding to the radius of curvature, is the wavelength, 8-10 mm, corresponding to the weft density, is the phase difference, 15°-20°, and the gradient distribution realizes the angle; The bionic sine wave structure makes the stress distribution of the fabric uniform during stretching and improves the elastic recovery rate.

[0046] The binding paths of traditional woven fabrics are mostly straight lines or simple broken lines, resulting in stress concentration at the binding points during stretching, which easily causes elastic fiber fracture or plastic deformation; this application adopts a bionic sine wave structure, and the continuous curvature change of the sine wave highly coincides with the skin deformation trajectory when the human joint bends. The fabric can naturally stretch with the limbs during movement, reducing the sense of restraint; the gradient curvature of the sine wave path makes the tensile stress evenly distributed along the curve, avoiding excessive local stress.

[0047] In step S4, the damage problem of elastic fibers caused by traditional water dyeing process is solved by supercritical CO2 dyeing and finishing, and finally the comprehensive performance improvement of high color fastness and low damage is achieved.

[0048] Supercritical CO2 (SC-CO2) refers to a CO2 fluid with temperature and pressure exceeding the critical point (31.1 °C, 7.38 MPa). It has both the diffusivity of gas and the solubility of liquid, and is used as an environmentally friendly solvent to replace the traditional water dyeing process. In this process, SC-CO2 dissolves disperse dyes and penetrates into the fiber interior to complete dyeing, avoiding the damage to the molecular chains of PBT / PTT composite fibers caused by high-temperature high-pressure water dyeing.

[0049] The high-pressure supercritical dyeing and finishing kettle has a volume of 45 - 50L, a temperature resistance of 200°C, and a pressure resistance of 30MPa; the temperature of CO2 is 80 - 100°C, the pressure is 15 - 20MPa, the dye type is disperse dye, and the dosage is 2 - 3%; the circulation time is 60 - 80min to ensure that the dye fully penetrates into the fiber interior. After completion, the pressure relief rate is 0.5 - 1MPa / min, and slow pressure relief is carried out to avoid generating microcracks inside the fiber.

[0050] The supercritical CO2 dyeing and finishing process uses CO2 fluid in the supercritical state to replace the traditional water medium. Through its characteristics of both gas diffusivity and liquid solubility, the disperse dye is efficiently penetrated into the interior of the PBT / PTT composite fiber to achieve waterless dyeing, avoiding thermal damage to the fiber molecular chain under high temperature and high pressure, and at the same time ensuring that the dye is evenly distributed in the fiber amorphous region to improve color fastness.

[0051] In step S5, through the uniform loading of graphene nanosheets, the fabric is given high conductivity, antistatic property, and abrasion resistance, solving the problems of weak antistatic ability and easy wear during long-term use of traditional elastic fabrics due to the absence of spandex.

[0052] Prepare the finishing solution. Add graphene nanosheets, dispersant, and binder to deionized water in proportion, and treat it with an ultrasonic disperser at a frequency of 40kHz and a power of 500W for 20 - 30min to form a stable suspension; The diameter of the graphene nanosheets is 50 - 100nm, which is matched with the size of the graphene masterbatch used for warp modification in S1 to enhance the interfacial bonding. The concentration is 1 - 2g / L to ensure a moderate loading amount and avoid excessive amount affecting the hand feeling; The dispersant uses sodium dodecylbenzenesulfonate, with a concentration of 0.5 - 1g / L, to prevent graphene aggregation through electrostatic repulsion, and the Zeta potential ≥ - 30mV; The binder uses waterborne polyurethane, with a concentration of 3 - 5g / L, to improve the bonding fastness between graphene and the fiber, and the peel strength ≥ 0.6N / cm; The solvent uses water.

[0053] Make the graphene nanosheets uniformly adhere to the fabric surface and fiber gaps through padding; the padding temperature is 25 ± 2°C to avoid the failure of the dispersion liquid due to high temperature; the liquor ratio is 60 - 70% to control the graphene loading amount. Excessive amount will reduce the elasticity, and insufficient amount will result in weak function; the padding pressure is 0.3 - 0.5MPa to ensure that the suspension fully penetrates into the fabric interior, especially at the intersection points of warp and weft yarns.

[0054] Pre-drying and baking are carried out for film formation and curing, removing moisture and curing the graphene / binder film layer to enhance the bonding fastness. The pre-drying temperature is 80 - 90 °C, and the time is 3 - 5 min. Slowly raise the temperature to avoid rapid evaporation of moisture, which may cause graphene agglomeration. The baking temperature is 120 - 130 °C, and the time is 2 - 3 min to trigger the cross-linking reaction of the waterborne polyurethane to form a stable film layer.

[0055] Example 1: A method for preparing an ammonia-free spandex elastic woven fabric includes the following steps: S1. Prepare warp yarns, surface warp yarns, and weft yarns. Among them, the warp yarns are formed by blending PBT / PTT chips with a mass ratio of 1.2:1, graphene masterbatch with a particle diameter of 75 nm and a proportion of 0.4%, and nano-silica with a particle diameter of 25 nm and a proportion of 0.2% and melting them. Then, they are extruded at 265 °C through a twin-screw spinning machine. The diameter of the spinning machine screw is Φ45 mm, the length-diameter ratio L / D = 32:1, the diameter of the spinning nozzle is 0.22 mm, and the number of holes in the spinneret is 30. The composite filaments are blended with shape memory polymer staple fibers with a length of 45 mm and accounting for 10% of the total amount of warp yarns through a drawframe. The doubling number is 7, the roller gauge is 34 mm, and the delivery speed is 42 m / min to form a blended yarn. The blended yarn is subjected to multi-stage drafting treatment. The first-stage drafting temperature is 82 °C, and the drafting ratio is 3.6:1. The second-stage drafting temperature is 122 °C, and the drafting ratio is 1.3:1. The winding speed is 3650 m / min to obtain modified composite warp yarns. The surface warp yarns are made by selecting superfine denier polyamide long filaments with a denier of 0.5 D and a single filament diameter of 15 μm as the base material. The surface oil agent is removed by treating in a 5% NaOH solution at 60 °C for 10 min. Under the chemical vapor deposition conditions of an argon flow rate of 450 sccm, a methane flow rate of 90 sccm, and a reaction temperature of 620 °C, carbon nanotubes with a tube diameter of 15 nm and a purity of 98% are uniformly loaded on the surface of the polyamide fiber. The dispersant is sodium dodecyl sulfate with a concentration of 0.55%, and the carbon nanotube loading is 0.12% to form a functional coating. The weft yarns are made by using PTT staple fibers with a length of 38 mm as the core layer, and the outer layer selects Yaser staple fibers with a length of 38 mm and a grooved structure, with a mass ratio of 1:2.3. Under the conditions of a ring spinning frame with a spindle speed of 15500 rpm, a PTT core yarn tension of 4 cN, a back zone draft of 1.25 times, and a twist of 103.5 turns / 10 cm, the Yaser staple fibers are uniformly coated on the surface of the core yarn to form a tight core-spun structure. S2. Pretreat the warp and weft yarns. For the warp yarns, the atmospheric pressure and low-temperature plasma technology is adopted, using an argon-oxygen mixed gas with a volume ratio of 3.2:1 as the medium, and treating them for 25 s through a plasma generator with a radio frequency power supply frequency of 13.5 MHz and a power of 450 W, etching nano-scale micropores with a pore diameter of 75 nm on the fiber surface and introducing active groups such as hydroxyl and carboxyl groups; for the weft yarns, a compound system of cellulase and pectinase with a mass ratio of 2.3:1 and a total concentration of 22 g / L is used, and they are treated for 35 min under the conditions of a temperature of 48 °C, a pH value of 5.8, an ultrasonic frequency of 40 kHz, and a power of 350 W to remove the pectin, amorphous cellulose of the Yaser fiber, and the spinning oil agent of the PTT fiber; S3. Weave the warp and weft yarns by a smart loom to form a base fabric. Among them, the smart loom dynamically adjusts the warp tension through an AI tension control system, with the warp tension being 13.5 N and the surface warp tension being 9 N; the magnetic levitation multi-shuttle rapier weft insertion technology is used, with a suspension height of 0.8 mm, a weft insertion speed of 900 m / min, a weft density of 435 per 10 cm, and a suspension magnetic field strength of 0.15 T; then, based on the digital twin model, the path of the interlacing warp yarns is optimized to form a bionic sine wave structure with a sine wave curvature radius of 10 mm, an angle gradient of 40°, and an interlacing warp yarn spacing of 2.5 mm; S4. Supercritical CO2 dyeing and finishing is carried out on the base fabric, circulating for 70 min under the conditions of a CO2 temperature of 90 °C, a pressure of 18 MPa, and a disperse dye dosage of 2.5%, and the pressure relief rate is 0.8 MPa / min; S5. The dyed fabric is treated by dipping and rolling with graphene nanosheets. Graphene nanosheets with a sheet diameter of 75 nm, a concentration of 1.5 g / L, a sodium dodecylbenzenesulfonate dispersant with a concentration of 0.8 g / L, and an aqueous polyurethane binder with a concentration of 4 g / L are added to deionized water, and they are treated for 25 min through an ultrasonic disperser with a frequency of 40 kHz and a power of 500 W to form a stable suspension. Under the conditions of a dipping and rolling temperature of 25 °C, a liquor pickup rate of 65%, and a padding mangle pressure of 0.4 MPa, the graphene nanosheets are uniformly attached to the fabric surface and fiber gaps, and then cured into a film through pre-drying at a temperature of 85 °C for 4 min and baking at a temperature of 125 °C for 2.5 min to obtain an elastane-free elastic woven fabric.

[0056] Example 2:

[0057] A method for preparing an elastane-free elastic woven fabric is the same as that in Example 1 and will not be repeated here. The difference is that the mass ratio of PBT / PTT is 1:1.

[0058] Example 3:

[0059] A method for preparing an elastane-free elastic woven fabric is the same as that in Example 1 and will not be repeated here. The difference is that the mass ratio of PBT / PTT is 1.1:1.

[0060] Example 4: A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 1 and will not be described again. The difference is that the mass ratio of PBT / PTT is 1.3:1.

[0061] Example 5:

[0062] A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 1 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.3%.

[0063] Example 6:

[0064] A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 2 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.3%.

[0065] Example 7:

[0066] A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 3 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.3%.

[0067] Example 8:

[0068] A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 4 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.3%.

[0069] Example 9:

[0070] A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 1 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.5%.

[0071] Example 10:

[0072] A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 2 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.5%.

[0073] Example 11: A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 3 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.5%.

[0074] Example 12: A method for preparing an ammonia-free elastic woven fabric is the same as that in Example 4 and will not be described again. The difference is that the proportion of graphene masterbatch is 0.5%.

[0075] Example 13: A method for preparing an ammonia-free elastic woven fabric, which is the same as that in Example 1 and will not be repeated here. The difference lies in: the angle gradient is 38°.

[0076] Example 14: A method for preparing an ammonia-free elastic woven fabric, which is the same as that in Example 1 and will not be repeated here. The difference lies in: the angle gradient is 42°.

[0077] Comparative Example 1: A method for preparing an ammonia-free elastic woven fabric, which is the same as that in Example 1 and will not be repeated here. The difference lies in: the proportion of graphene masterbatch is 0.

[0078] Experiment 1: In this experiment, Examples 1 to 12 and Comparative Example 1 were used for experiments to verify the elasticity and recovery ability of the fabric: The fixed elongation recovery rate was tested according to ASTM D3107; A 1000-cycle tensile test was carried out according to ISO 13934-1 to calculate the elastic loss rate; The surface resistance was tested according to ASTM D257; Table 1 Experimental parameters designed for Examples 1 to 12 and Comparative Example 1

[0079] The core reason for the best effect in Example 1 is that the synergistic effect of its key parameters with the elastic and antistatic properties of the material reaches the optimal balance.

[0080] From the analysis of the elastic mechanism, the molecular chain structure differences between PBT (polybutylene terephthalate) and PTT (polytrimethylene terephthalate) determine their functional complementarity: the rigid benzene ring structure of PBT provides the backbone support for the molecular chain and inhibits excessive deformation; the flexible propylene glycol chain segment of PTT stores elastic potential energy through the "helix-straightening" conformational transformation. When the mass ratio of PBT / PTT is 1.2:1, the ratio of rigid and flexible chain segments reaches the critical balance - it not only avoids the excessive hardness caused by too high a proportion of PBT (such as the decrease in elastic recovery rate when it is 1:1 in Example 2), but also prevents the aggravation of molecular chain slippage caused by too high a proportion of PTT (such as the slightly increased elastic loss rate when it is 1.3:1 in Example 4). Therefore, it can efficiently store and release elastic potential energy during stretching, showing the highest elastic recovery rate and the lowest elastic loss rate.

[0081] From the perspectives of antistatic and elasticity enhancement, the critical dispersion threshold of graphene masterbatch in the PBT / PTT matrix is 0.4%: the high conductivity of graphene can form a continuous conductive network inside the fiber, effectively reducing charge accumulation; at the same time, its nanosheet structure is embedded between PBT / PTT molecular chains through the "mechanical locking" effect, forming a "spring-damping" biphasic structure - the graphene sheets act as "miniature springs" to enhance the elastic recovery ability, while the interfacial friction between it and the matrix acts as "damping" to inhibit energy dissipation during cyclic stretching (the lowest elastic loss rate). If the proportion of graphene is less than 0.4%, the conductive network and mechanical locking effect are insufficient, and both the surface resistance and elastic loss rate increase; if it is higher than 0.4%, graphene is prone to agglomeration and form defects, which instead destroys the molecular chain continuity and leads to performance degradation.

[0082] In summary, through the synergistic effect of the precise regulation of the PBT / PTT ratio and the critical filling amount of graphene in Example 1, the optimal matching of elasticity and antistatic performance is achieved, so it performs best in the experiment. Experiment 2: In this experiment, Example 1 and Examples 13 to 14 were used for the experiment to verify the elasticity and recovery ability of the fabric: Simulate the elastic recovery rate after 1000 bends of human joints; Simulate the elastic loss rate after 1000 bends of human joints; Table 2 Experimental parameters designed in Example 1 and Examples 13 to 14

[0083] The core reason for the best effect in Example 1 is that its angle gradient, stress distribution and structural stability of material elastic deformation have achieved the optimal matching.

[0084] Analyzed from the principle of elastic deformation, the elastic recovery rate and energy loss rate during cyclic stretching of materials are directly related to the deformation-recovery mechanism of their microstructures when stressed. The angle gradient determines the degree of stress dispersion and concentration in the material during stretching: when the angle gradient is 40°, the orientation of fibers / molecular chains inside the material forms the best angle with the stretching direction - it not only avoids the increase in friction between fibers caused by too small an angle, but also prevents the expansion of stress concentration areas caused by too large an angle. This critical angle makes the deformation energy during stretching evenly distributed in each part of the material, and the molecular chains or fibers can efficiently undergo "stretching-shrinking" reversible deformation, with the highest efficiency of elastic potential energy storage and release and the minimum energy dissipation during cyclic stretching.

[0085] An angular gradient of 40° deviation will disrupt this stress balance: at 38°, the contact area between fibers increases, and frictional heat generation causes more energy to be dissipated in the form of heat; at 42°, the angle between some fibers and the stretching direction is too large, and irreversible plastic deformation is likely to occur in local areas. Therefore, the 40° angular gradient in Example 1 achieves the highest elastic recovery ability and the lowest cyclic tensile energy loss by optimizing the synergy between stress distribution and structural deformation, showing the best performance.

[0086] Based on the ideal embodiments of the present invention as inspiration, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A preparation method of an ammonia-free elastic woven fabric, It is characterized in that it includes: S1. Prepare warp yarns, face warp yarns and weft yarns. Among them, the warp yarns are prepared by blending and modifying PBT / PTT fibers with graphene and nano-silica and blending with shape memory polymer staple fibers; the face warp yarns are prepared by superfine denier polyamide fiber coated with carbon nanotubes on the surface; the weft yarns are prepared by Yaser and PTT bicomponent core-spun yarns. S2. Pretreat the warp yarns and weft yarns. Among them, the warp yarns are activated, and the weft yarns are decontaminated. S3. Perform intelligent weaving on the warp yarns and weft yarns to form a base fabric with a bionic sine wave joint structure. Among them, the bionic sine wave joint structure is a continuous curvature joint path that simulates the bending curvature of human joints and the distribution of motion stress. S4. Perform supercritical CO2 dyeing and finishing on the base fabric. S5. Immerse and roll the dyed fabric with graphene nanosheets to obtain an elastic woven fabric without spandex.

2. The preparation method of an ammonia-free elastic woven fabric according to claim 1, characterized in that: The preparation of the warp yarns in step S1 includes the following sub-steps: Blend and melt PBT / PTT chips with graphene masterbatch and nano-silica, and extrude through a twin-screw spinning machine to form composite filaments. Among them, the mass ratio of PBT to PTT is 1-1.3:1, the sheet diameter of the graphene masterbatch is 50-100 nm and the proportion is 0.3-0.5%, the particle size of nano-silica is 20-30 nm and the proportion is 0.1-0.3%, the melting temperature of PBT / PTT chips is 260-270 °C, the mixing time is 15-20 min, and the rotation speed is 300-400 rpm; the screw diameter of the twin-screw spinning machine is Φ45 mm, the length-diameter ratio L / D = 32:1, the aperture of the spinning nozzle is 0.2-0.25 mm, and the number of holes in the spinneret is 24-36. Blend the composite filaments with shape memory polymer staple fibers through a drawframe to form a blended yarn. Among them, the length of SMP is 38-51 mm and it accounts for 10% of the total amount of warp yarns, the number of drawn strands is 6-8, the roller gauge is 32-35 mm, and the delivery speed is 40-45 m / min. Perform multi-stage drawing treatment on the blended yarn to obtain modified composite warp yarns. Among them, the primary drawing temperature is 80-85 °C, and the drawing ratio is 3.5-3.7:1; the secondary drawing temperature is 120-125 °C, and the drawing ratio is 1.2-1.5:1; the winding speed is 3500-3800 m / min.

3. The preparation method of an ammonia-free elastic woven fabric according to claim 1, characterized in that: The preparation of the face warp yarns in step S1 includes the following sub-steps: Select superfine denier polyamide filament as the base material and pretreat it with 5% NaOH solution to remove the surface oil agent. Among them, the denier of the superfine denier polyamide filament is 0.4-0.6 D, the single filament diameter is 10-20 μm, the pretreatment temperature is 60 °C, and the treatment time is 10 min. Under argon protection, carbon nanotubes were uniformly loaded on the surface of polyamide fiber by chemical vapor deposition to form a functional coating; among them, the argon flow rate was 400 - 500 sccm, the carbon source was methane and the flow rate was 80 - 100 sccm, the reaction temperature was 600 - 650 °C, and the coating time was 10 - 15 min; the diameter of the quartz tube of the chemical vapor deposition device was Φ80 - 100 mm, and the length of the heating zone was 250 - 300 mm; the diameter of the carbon nanotubes was 10 - 20 nm, the purity was ≥95%, and the loading amount was 0.1 - 0.15%.

4. A method for preparing an ammonia-free elastic woven fabric according to claim 1, characterized in that: The preparation of the weft yarn in step S1 includes the following sub - steps: Using PTT staple fiber as the core layer and selecting Yaser staple fiber with a groove structure for the outer layer, the Yaser staple fiber was uniformly wrapped on the surface of the PTT core yarn by a ring spinning frame to form a two - component core - spun yarn; among them, the lengths of both the PTT staple fiber and the Yaser staple fiber were 35 - 40 mm, and the mass ratio of PTT to Yaser was 1:2.2 - 2.4; the spindle speed of the ring spinning frame was 15000 - 16000 rpm, the tension of the PTT core yarn was 3 - 5 cN, the draft multiple in the back zone was 1.2 - 1.3 times, and the twist was 101.3 - 105.6 turns / 10 cm.

5. The preparation method of an ammonia-free elastic woven fabric according to claim 1, characterized in that: In step S2, the activation treatment of the warp yarn uses the atmospheric pressure low - temperature plasma technology with an argon - oxygen mixed gas as the medium; among them, the volume ratio of argon to oxygen is 3 - 3.5:1, and the total flow rate is 200 - 300 sccm; radio - frequency power is used for treatment, the frequency is 13 - 14 MHz, the power is 400 - 500 W, and the treatment time is 20 - 30 s; after treatment, nano - scale micropores with a pore diameter of 50 - 100 nm are etched on the fiber surface, and hydroxyl and carboxyl active groups are introduced.

6. The preparation method of an ammonia-free elastic woven fabric according to claim 1, characterized in that: In step S2, the impurity removal treatment of the weft yarn uses a compound system of cellulase and pectinase; among them, the mass ratio of cellulase to pectinase is 2 - 2.5:1, and the total concentration is 20 - 25 g / L; the treatment is carried out under ultrasonic assistance, the ultrasonic frequency is 40 kHz, and the power is 300 - 400 W; the treatment conditions are: temperature 45 - 50 °C, time 30 - 40 min, pH value 5.5 - 6.0, and the mass ratio of the yarn to the solution is 1:20 - 23.

7. A method for preparing an ammonia-free elastic woven fabric according to claim 1, characterized in that: The specific parameters of the intelligent weaving in step S3 include: The AI tension control system uses an optical fiber tension sensor with an accuracy of ±0.1 N, a sampling frequency of 80 - 2100 Hz, and adjusts the rotational speed of the let - off motor based on the LSTM dynamic tension prediction model to ensure that the warp yarn tension fluctuation range ≤ ±0.3 N; among them, the warp yarn tension is 12 - 15 N, and the surface warp yarn tension is 8 - 10 N; The electromagnetic suspension multi - shed weft insertion uses an electromagnetic suspension guide rail, with a suspension height of 0.5 - 1 mm, a magnetic field strength of 0.1 - 0.2 T, a weft insertion speed of 800 - 1000 m / min, and a weft yarn density of 420 - 450 pieces / 10 cm; The bionic sine wave structure parameters optimized for the digital twin model are: the radius of curvature is 8-12 mm, the angle gradient is 38°-42°, increasing from the center of the fabric to the edge, the distance between the binding warp yarns is 2-3 mm, and the spatial coordinate expression is , where is the amplitude, 2-3 mm, is the wavelength, 8-10 mm, is the phase difference, 15°-20°.

8. The preparation method of an ammonia-free elastic woven fabric according to claim 1, characterized in that: The parameters of the supercritical CO2 dyeing and finishing in step S4 are: CO2 temperature 80 - 100 °C, pressure 15 - 20 MPa, the dosage of disperse dye 2 - 3%, the circulation time 60 - 80 min, and the pressure relief rate 0.5 - 1 MPa / min.

9. The preparation method of an ammonia-free elastic woven fabric according to claim 1, characterized in that: The parameters of the padding treatment of graphene nanosheets in step S5 are as follows: the diameter of the graphene nanosheets is 50 - 100 nm, and the concentration is 1 - 2 g / L; the dispersant is sodium dodecylbenzenesulfonate, with a concentration of 0.5 - 1 g / L and a Zeta potential ≥ -30 mV; the binder is aqueous polyurethane, with a concentration of 3 - 5 g / L; the suspension is prepared by ultrasonic dispersion at a frequency of 40 kHz, a power of 500 W, and a time of 20 - 30 min; the padding temperature is 25 ± 2 °C, the liquor pickup rate is 60 - 70%, and the padding pressure is 0.3 - 0.5 MPa; the pre-drying temperature is 80 - 90 °C, the time is 3 - 5 min, the curing temperature is 120 - 130 °C, and the time is 2 - 3 min.

10. A spandex-free stretch woven fabric, based on the method for preparing a spandex-free stretch woven fabric according to any one of claims 1-9, characterized in that: The fabric is composed of warp yarns, surface warp yarns, and weft yarns working together. Among them, the warp yarns are the longitudinal elastic support layer, the surface warp yarns are the surface functional layer, and the weft yarns are the transverse moisture-absorbing elastic layer; the fabric has a bionic sine wave interlacing structure, with a sine wave curvature radius of 8 - 12 mm, an angle gradient of 38° - 42°, increasing from the center to the edge, and the interlacing warp yarn spacing of 2 - 3 mm; high color fastness is achieved through supercritical CO2 dyeing and finishing, thermosensitive active elastic recovery is imparted through thermosensitive memory finishing, with a triggering temperature of 37 ± 2 °C, and antistatic and friction resistance properties are improved through the loading of graphene nanosheets.

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