Anti-static knitted fabric based on charge aggregation and directional guidance and preparation method and knitted fabric thereof

Abstract

The application provides an anti-static knitted fabric based on charge accumulation and directional guidance, a preparation method thereof and a knitted fabric, and belongs to the technical field of knitted clothes. The first spinning component and the second spinning component are co-extruded through melt spinning to prepare a composite fiber with a parallel composite structure, and a composite yarn is obtained through thermal mechanical treatment; the composite yarn is introduced into a specific area of the fabric in a tuck-welt organization through an inlaying process, and latent crimping is activated through after-finishing. The application utilizes the hygroexpansion of the second spinning component to drive macroscopic self-crimping of the composite yarn, and constructs an efficient conductive framework by physical extrusion of the internal conductive filler, so that humidity response adjustment of the anti-static performance and directional dissipation of the charge are realized, the problems of fixed conductive state, local static accumulation and poor comfort of the existing fabric are effectively solved, and the safety and wearing experience of the clothes are improved.

Description

Technical Field

[0001] This invention belongs to the field of knitted apparel technology, specifically relating to an antistatic knitted fabric based on charge aggregation and directional guidance, its preparation method, and the knitted fabric. Background Technology

[0002] Antistatic knitted fabrics, due to their ability to suppress static electricity buildup and reduce static hazards, are widely used in everyday knitted apparel such as sweatshirts and sweatpants. Existing technologies for preparing antistatic knitted fabrics are based on the construction of conductive pathways, including full-width blending of conductive fibers, conductive coating finishing, and composite spinning to prepare composite fibers before weaving. Specifically, conductive fiber blending technology involves blending conductive fibers such as stainless steel fibers and carbon fibers with conventional textile fibers in a certain proportion, using the conductive fibers to construct a continuous conductive pathway to achieve charge dissipation; conductive coating finishing technology involves coating the fabric surface with a conductive paste to form a conductive film, achieving an antistatic effect; and composite spinning technology incorporates conductive fillers into the spinning raw materials, preparing composite fibers for weaving, thus improving the fabric's antistatic durability.

[0003] While existing technologies can achieve basic antistatic functions, several technical shortcomings limit their application effectiveness and adaptability to various scenarios. Firstly, current solutions generally lack humidity-responsive characteristics; the conductivity of the conductive path is fixed and cannot adaptively adjust to changes in ambient humidity. In dry environments, some solutions are prone to electrostatic discharge due to excessive conductivity, while in high-humidity environments, the antistatic performance of some solutions deteriorates due to moisture absorption and aging of the conductive filler. Secondly, the conductive paths constructed by existing technologies are non-directional, with charges randomly spreading within the fabric. This makes it difficult to precisely dissipate static electricity in areas prone to accumulation (such as cuffs, hems, and collars), leaving the problem of localized static accumulation unresolved. Furthermore, to ensure antistatic effectiveness, existing solutions often require increasing the amount of conductive fibers or functional materials, which not only increases manufacturing costs but also easily leads to stiff fabric feel, reduced breathability, and compromised wearing comfort.

[0004] Furthermore, in composite fibers prepared by conventional composite spinning, the conductive filler exhibits poor dispersion uniformity, easily leading to agglomeration and disrupting the continuity of the conductive path. Meanwhile, full-width blending or coating processes suffer from uneven distribution of functional materials, resulting in insufficient stability of antistatic performance and easy performance degradation due to friction and washing after long-term use. These technical deficiencies make it difficult for existing antistatic knitted fabrics to simultaneously achieve safety, comfort, and economy for everyday wear, failing to meet consumers' refined demands for antistatic effects and wearing experience in everyday knitted garments such as sweatshirts and sweatpants.

[0005] Therefore, developing antistatic knitted fabric preparation technology with humidity response characteristics, directional dispersion function and stable performance is an important research and development direction in the current field of everyday knitted apparel. Summary of the Invention

[0006] This invention overcomes the shortcomings of the prior art and provides an antistatic knitted fabric based on charge accumulation and directional guidance, a method for preparing the fabric, and the knitted fabric itself.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for preparing an antistatic knitted fabric based on charge accumulation and directional guidance, comprising the following steps:

[0008] S1: The first spinning component and the second spinning component are melted separately and co-extruded by melt spinning to form a composite fiber with a parallel composite structure; the first spinning component includes a matrix resin and a conductive filler, and the conductive filler is a fibrous conductive material and a granular conductive material with a mass ratio of 1:3 to 1:5; the second spinning component is a polyether block amide resin or polyethylene glycol modified polyethylene terephthalate;

[0009] S2: The composite fibers are sequentially stretched and heat-set to obtain composite yarn;

[0010] S3: Divide the fabric plane into non-conductive and conductive areas. Use basic yarns to weave in the non-conductive areas, and use tuck weaving or padding to introduce composite yarns in the conductive areas. The composite yarns form a tuck-float structure in the conductive areas and are woven together with the basic yarns to form the knitted fabric. The yarn arrangement density in the conductive areas is 1 composite yarn inserted for every 8 to 16 basic yarns woven.

[0011] S4: Perform finishing on the knitted greige fabric to obtain antistatic knitted fabric.

[0012] Preferably, in step S1, the matrix resin of the first spinning component is polybutylene terephthalate resin.

[0013] Preferably, in step S1, the fibrous conductive material is selected from one or more of vapor-grown carbon fibers, multi-walled carbon nanotubes, and conductive carbon fibers; the particulate conductive material is selected from one or more of conductive carbon black, graphene microsheets, and carbon aerogel particles.

[0014] Preferably, in step S1, melt spinning is performed using an independent temperature-controlled dual-channel composite spinning device, and the mass flow ratio of the first spinning component to the second spinning component is set to 40:60 to 60:40; the melts of the first spinning component and the second spinning component converge at a parallel composite spinneret to form a parallel melt stream, which is then cooled and solidified by side blowing to form a composite fiber.

[0015] Preferably, in step S2, the stretching process includes a preheating stage and a stretching stage; the preheating temperature in the preheating stage is 80°C to 100°C, the stretching zone temperature is 130°C to 150°C, and the total stretching ratio is 3.0 to 4.5 times; the heat setting temperature is 160°C to 180°C, the processing time is 30s to 60s, and a tension of 0.5cN / dtex to 1.5cN / dtex is applied to the fiber.

[0016] Preferably, in step S3, the base yarn is selected from one or more of combed cotton yarn, viscose fiber yarn, polyester staple fiber yarn and polyamide filament yarn.

[0017] Preferably, in step S4, the finishing process includes pretreatment, pre-drying, and stretching heat setting in sequence; the pretreatment includes relaxation and swelling in warm water at 50°C to 60°C, and refining and impurity removal in a refining solution at 70°C to 80°C; the pre-drying adopts a hot air penetration method with an air temperature of 90°C to 110°C, forming an overfeed of 5% to 10%.

[0018] Preferably, in step S4, the pretreatment includes relaxation and swelling in warm water at 50°C to 60°C, and refining and impurity removal in a refining solution at 70°C to 80°C; the pre-drying adopts a hot air penetration method with an air temperature of 90°C to 110°C, forming an overfeed of 5% to 10%; the temperature for stretching and heat setting is set at 170°C to 185°C for 30s to 45s, and the overfeed rate is set at 10% to 20%.

[0019] Another technical solution provided by the present invention: an antistatic knitted fabric based on charge accumulation and directional guidance, which is prepared by the above-mentioned preparation method.

[0020] Another technical solution provided by the present invention is an antistatic knitted fabric, which is obtained by processing the above-mentioned antistatic knitted fabric.

[0021] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0022] This invention constructs a composite fiber with a parallel composite structure based on a second spinning component and a first spinning component, and combines it with an interlocking weaving process to achieve coordinated control from microscopic particle arrangement to macroscopic fabric structure. While ensuring daily wearing comfort and breathability, it significantly improves the static dissipation efficiency and safety of the fabric under different humidity environments, meeting the refined protection needs of knitted garments in complex application scenarios.

[0023] This invention utilizes a first spinning component and a second spinning component to prepare a composite fiber with a parallel composite structure through composite spinning. The asymmetric stress generated by the volume expansion of the second spinning component after moisture absorption drives the composite fiber to undergo macroscopic self-curling deformation. This, in turn, applies physical compression to the side of the parallel-bonded first spinning component, forcing the fibrous and granular conductive materials dispersed in the matrix to approach each other and increase contact points. This allows the composite fiber to remain relaxed in a dry environment to maintain its basic antistatic properties, while automatically constructing a continuous, highly efficient conductive framework in high humidity or sweating environments, rapidly reducing volume resistivity. Compared to existing single conductive fibers with constant conductivity that cannot change with the environment, this invention achieves intelligent humidity-responsive regulation of conductivity, avoiding the risk of over-discharge in dry environments and overcoming performance degradation caused by filler aging in high humidity environments. This significantly improves the stability and environmental adaptability of the antistatic function.

[0024] This invention utilizes an inlay weaving process to orient composite yarns into areas of the fabric prone to static electricity accumulation using a loop-float structure. The long float structure provides free deformation space for the composite yarns to absorb moisture and curl, while the loop points achieve physical anchoring and contact positioning of the composite yarns on the inside of the fabric. This ensures that the composite yarns generate inward micro-shrinkage force when absorbing moisture and shrinking, resulting in a closer fit to the skin and creating directional conductive channels for key areas such as cuffs and hems. Compared to existing technologies that use full-width blends or conductive coatings, which result in stiff fabrics, poor breathability, and random charge diffusion, this invention achieves precise charge dissipation while maximizing the preservation of the soft touch and breathability of the knitted fabric structure, achieving an effective balance between functionality and wearing comfort.

[0025] In this invention, the microscopic conductive network constructed by the optimized ratio of fibrous and granular conductive materials within the composite yarn exhibits a significant synergistic effect with the crimping compression field provided by the macroscopic weaving density of the fabric. Under wet conditions, the shrinkage stress generated by the macroscopic crimping of the composite yarn not only macroscopically tightens the conductive channels but also provides appropriate compression energy at the microscopic level, repairing microscopic breakpoints in the conductive filler skeleton and lowering the electron transition barrier. The specific weaving density ensures that these deformations do not interfere with each other and that stress transfer is maximized. This coupling of macroscopic deformation and microscopic conductive mechanism results in a non-linear increase in the fabric's conductivity, overcoming the problem of decreased mechanical properties caused by simply increasing filler content. This leads to superior and more durable electrostatic dissipation capabilities even with low filler content. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart of a method for preparing antistatic knitted fabrics based on charge accumulation and directional guidance. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0030] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] Unless otherwise specified, all raw materials described below may be commercially available or prepared using conventional methods in the art.

[0033] like Figure 1 As shown, a method for preparing an antistatic knitted fabric based on charge accumulation and directional guidance includes the following steps:

[0034] S1: The first spinning component and the second spinning component are melted separately and co-extruded by melt spinning to form a composite fiber with a parallel composite structure; the first spinning component includes a matrix resin and a conductive filler, and the conductive filler is a fibrous conductive material and a granular conductive material with a mass ratio of 1:3 to 1:5; the second spinning component is a polyether block amide resin or polyethylene glycol modified polyethylene terephthalate;

[0035] S2: The composite fibers are sequentially stretched and heat-set to obtain composite yarn;

[0036] S3: Divide the fabric plane into non-conductive and conductive areas. Use basic yarns to weave in the non-conductive areas, and use tuck weaving or padding to introduce composite yarns in the conductive areas. The composite yarns form a tuck-float structure in the conductive areas and are woven together with the basic yarns to form the knitted fabric. The yarn arrangement density in the conductive areas is 1 composite yarn inserted for every 8 to 16 basic yarns woven.

[0037] S4: Perform finishing on the knitted greige fabric to obtain antistatic knitted fabric.

[0038] Below, each step will be explained in detail.

[0039] In step S1, by taking advantage of the physical difference in the hygroscopic and swelling properties of the first spinning component and the second spinning component, nascent fibers with a parallel composite structure, i.e., composite fibers, are prepared by melt spinning.

[0040] This step involves the preparation of the first spinning component, the preparation of the second spinning component, and melt spinning.

[0041] The first spinning component consists of a matrix resin and conductive fillers. The matrix resin is polybutylene terephthalate (PET). PET is a semi-crystalline thermoplastic polyester with a melting point range of 220°C to 230°C and an intrinsic viscosity of 0.8 dL / g to 1.0 dL / g. It exhibits a high crystallization rate, allowing for rapid setting during the cooling stage after melt spinning, and its rigid molecular chain structure provides mechanical support for the conductive network.

[0042] Conductive fillers include fibrous conductive materials and particulate conductive materials.

[0043] The fibrous conductive material is selected from one or more of vapor-grown carbon fibers, multi-walled carbon nanotubes, and conductive carbon fibers.

[0044] For example, vapor-grown carbon fibers have diameters ranging from 10 nm to 50 nm and aspect ratios ranging from 100 to 500. Vapor-grown carbon fibers have a high degree of surface graphitization and strong axial conductivity, enabling the construction of long-distance conductive skeletons in the matrix. However, due to their relatively large diameter, the filling density in the micro-regions is limited.

[0045] For example, multi-walled carbon nanotubes have diameters ranging from 5 nm to 20 nm and aspect ratios greater than 1000. The extremely high aspect ratio of multi-walled carbon nanotubes allows them to form a percolation network even at low addition levels, but the huge specific surface area results in significant van der Waals forces, leading to a tendency for agglomeration during melt mixing, requiring high-shear dispersion.

[0046] For example, conductive carbon fibers have a diameter of 5 μm to 10 μm and a length of 3 mm to 6 mm. Conductive carbon fibers have a high mechanical modulus and mainly provide physical support for macroscopic conductive pathways, but the number of conductive connection points inside micron-sized fibers is less than that in nanoscale materials.

[0047] The particulate conductive material is selected from one or more of conductive carbon black, graphene microplates, and carbon aerogel particles.

[0048] The conductive carbon black has a particle size of 20nm to 50nm and a specific surface area of ​​800m². 2 / g to 1200m 2 / g. Conductive carbon black has a well-developed branched chain structure, which can fill the gaps between fibrous materials and form short-range conductive overlaps. However, excessive shearing can easily destroy its aggregate structure, leading to a decrease in conductivity.

[0049] Graphene flakes range in thickness from 1 nm to 5 nm and in diameter from 1 μm to 10 μm. The two-dimensional planar structure of graphene flakes provides a large contact area for electron transport, which helps to reduce contact resistance. However, they are prone to surface-to-surface stacking in the substrate, which hinders the formation of three-dimensional networks.

[0050] The carbon aerogel particles have a porosity greater than 80% and a density less than 0.1 g / cm³.3 The three-dimensional nanoframework structure of carbon aerogel particles has continuous electron transport channels, but its mechanical strength is low and it is easily broken during extrusion.

[0051] The preparation process of the first spinning component is as follows:

[0052] A mixed filler is obtained by mixing dried fibrous conductive material with granular conductive material at a mass ratio of 1:3 to 1:5.

[0053] The mixed filler and polybutylene terephthalate resin were added to a high-speed mixer and premixed for 10 to 15 minutes at a speed of 1000 to 1500 r / min to obtain a premixed material.

[0054] The premixed material is fed into a co-rotating twin-screw extruder with an L / D ratio of 40:1 to 48:1. The barrel temperature is set sequentially from the feeding section to the die head section as 210℃ to 220℃, 225℃ to 235℃, 230℃ to 240℃, and 225℃ to 235℃. The screw speed is set to 200 r / min to 300 r / min. The shearing force generated by the kneading blocks in the screw assembly is used to disperse the conductive filler in the polybutylene terephthalate resin matrix. The extrudate is water-cooled, stretched, pelletized, and dried to obtain the first spinning component.

[0055] The second spinning component is selected from polyether block amide resin or polyethylene glycol modified polyethylene terephthalate.

[0056] Polyether block amide resins are composed of polyamide hard segments and polyether soft segments linked by amide bonds. The polyamide hard segments provide the crystalline phase, contributing to the material's mechanical strength and melting point (210°C to 220°C); the polyether soft segments provide the amorphous phase, containing numerous ether bonds and exhibiting hydrophilic and hygroscopic properties. Upon absorbing moisture, the polyether soft segments expand in volume, driving overall material deformation.

[0057] When polyether block amide resin is used as a second spinning component, it is prepared by polycondensation of dicarboxylated polyamide hard segments and polyether glycol soft segments under high temperature and catalytic conditions. The dicarboxylated polyamide hard segments are formed by the condensation of lactams, amino acids, or diacids with diamines. The polyether glycol soft segments include one or more of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran glycol, with ether bonds in the molecular chain providing hygroscopic swelling.

[0058] The specific process for preparing polyether block amide resin includes:

[0059] A mixture of carboxyl-terminated dicarboxylated polyamide hard segments and hydroxyl-terminated polyether glycol soft segments at a mass ratio of 30:70 to 70:30 is added to a reaction vessel. The esterification catalyst is selected from one or more of tetrabutyl titanate, tetraisopropyl titanate, and antimony-based catalysts. The amount of esterification catalyst added is controlled within the range of 0.01% to 0.1% of the total mass of the reactants.

[0060] Prepolymerization was carried out in an inert environment under nitrogen protection, with the internal temperature of the reactor set between 200°C and 240°C and the pressure maintained between 0.1 MPa and 0.3 MPa. Under this environment, the terminal groups of the dicarboxylated polyamide hard segment and the polyether glycol soft segment underwent an esterification reaction. After the prepolymerization reaction was completed, the reactor system pressure was gradually reduced from atmospheric pressure to 50 Pa to 100 Pa over 30 to 60 minutes, while the reactor temperature was raised to 240°C to 270°C. Under vacuum and high temperature conditions, the reaction system underwent a compression polymerization reaction, removing the water generated in the reaction to shift the equilibrium towards the product side and increase the molecular weight of the polymer.

[0061] During the reduced-pressure polypolymerization process, the reaction endpoint was determined by real-time monitoring of the stirring power. The reaction was stopped when the intrinsic viscosity of the polyether block amide resin reached the range of 0.8 dL / g to 1.2 dL / g. The resulting melt was removed from the reactor by vacuum pressing, followed by water cooling and solidification, pelletizing, and vacuum drying. The melting point of the polyether block amide resin produced in this process was controlled within the range of 210℃ to 220℃. The obtained polyether block amide resin possesses thermoplastic melt processing characteristics, and its physical state meets the rheological properties requirements for melt spinning.

[0062] Polyethylene glycol-modified polyethylene terephthalate (PEG) is a copolymer in which flexible polyethylene glycol segments are introduced into the main molecular chain of polyethylene terephthalate (PET). The PEG segments have high hygroscopicity, giving the copolymer moisture-responsive properties.

[0063] When polyethylene glycol-modified polyethylene terephthalate is selected as the second spinning component, the synthesis and modification process is as follows:

[0064] Terephthalic acid, ethylene glycol, and polyethylene glycol are added to a reactor in a molar ratio of 1:1.2:0.1 to 1:1.5:0.3. The number average molecular weight of the polyethylene glycol is 2000 g / mol to 6000 g / mol. Antimony trioxide is added as a catalyst at a concentration of 0.03% to 0.05% of the total mass of the reactants. Under nitrogen protection, the reactor temperature is controlled at 220°C to 240°C, and the pressure at 0.1 MPa to 0.3 MPa, to carry out the esterification reaction until the theoretical distillation yield of the water generated in the reaction reaches more than 95%.

[0065] The pressure in the reactor was reduced to 50 Pa to 100 Pa over 30 to 60 minutes, while the temperature was increased to 260°C to 275°C to initiate the polycondensation reaction. The reaction endpoint was controlled by monitoring the stirring power. The reaction was stopped when the intrinsic viscosity reached 0.7 dL / g to 0.9 dL / g, and the product was discharged and pelletized to obtain polyethylene glycol-modified polyethylene terephthalate with a melting point of 215°C to 225°C.

[0066] Composite fibers are prepared using an independently temperature-controlled dual-channel composite spinning equipment. The equipment includes a first screw extruder, a second screw extruder, a dual-channel spinning box, and parallel composite spinnerets.

[0067] The first spinning component is added to the first screw extruder, and the heating temperature is set to 230°C to 240°C. The second spinning component is added to the second screw extruder, and the heating temperature is set to 220°C to 235°C. The two component melts remain in a molten flow state within their respective flow channels, and the flow rates are precisely controlled by a metering pump, with the mass flow rate ratio of the first spinning component to the second spinning component set to 40:60 to 60:40.

[0068] Two components of melt enter a parallel composite spinneret. The spinneret orifices are designed to be circular, and the two components converge at the inlet of the spinneret orifice, maintaining a laminar flow state as they pass through the orifice, forming a parallel structure of fine melt streams. The spinneret temperature is controlled between 230℃ and 240℃.

[0069] After extrusion, the melt stream enters a side-blowing cooling device. The side-blowing temperature is 20°C to 25°C, the air velocity is 0.5 m / s to 1.0 m / s, and the relative humidity is 60% to 70%. Under the action of the cooling airflow, the melt stream solidifies to form nascent composite fibers. Due to the difference in crystallization rates between polybutylene terephthalate and the second spinning component, the cooling process introduces prestress into the fiber, storing potential energy for structural evolution during subsequent heat treatment.

[0070] The composite fibers present a two-component side-by-side cross-sectional structure, providing the fabric with adaptive conductivity adjustment function in response to environmental humidity.

[0071] In a dry environment with a relative humidity below 40%, the second spinning component is in a state of dehydration and shrinkage, with its molecular chains tightly packed. The composite fiber as a whole exhibits a straight or slightly curled shape, while the physical compressive force on the first spinning component side is relatively small. At this time, the fibrous conductive material and granular conductive material in the first spinning component remain dispersed, without forming an effective continuous electron transport channel. The composite fiber exhibits a basic antistatic state, sufficient to dissipate everyday weak static electricity and prevent excessive charge accumulation.

[0072] In humid environments with relative humidity above 60% or in contact with liquid sweat, the hydrophilic segments in the second spinning component capture water molecules, resulting in volume swelling. Since the first spinning component, bound side-by-side, is composed of a polybutylene terephthalate matrix, it has extremely low hygroscopicity and maintains stable volume. The asymmetry of volume changes between the two components generates axial shear stress and radial compressive stress at the fiber interface, driving macroscopic self-curling deformation of the composite fiber. The fiber's curling and shrinkage causes compression on the first spinning component side, forcing microscopic deformation of the internal polymer matrix. This reduces the spatial distance between the dispersed fibrous and granular conductive materials, increasing the physical contact nodes between the conductive fillers and constructing a continuous conductive framework. Simultaneously, some water molecules absorbed by the second spinning component permeate to the interface between the two components and the amorphous region of the first spinning component. Water molecules have a high dielectric constant, which lowers the potential barrier height between conductive particles, promoting electron tunneling transitions between non-contact particles.

[0073] The volume resistivity of the aforementioned composite fibers decreases rapidly in a wet state, achieving an automatic switch from basic antistatic properties to high conductivity and dissipation.

[0074] Step S2 involves performing thermomechanical treatment on the composite fiber prepared in step S1, including stretching and heat setting, to eliminate uneven internal stress within the composite fiber, improve the crystalline structure of the polymer matrix, and regulate the axial orientation of the fibrous conductive material, thereby obtaining a composite yarn with dimensional stability and humidity response potential.

[0075] In this step, the cooled and cured composite fibers are introduced into a multi-stage continuous hot stretching device. The hot stretching process is divided into a preheating stage and a stretching stage.

[0076] During the preheating stage, the composite fibers pass through a set of heating rollers or a hot air box. The preheating temperature is set to 80°C to 100°C, which is higher than the glass transition temperature of polybutylene terephthalate resin and the second spinning component. This allows the bicomponent polymer chains to acquire mobility, transitioning from a glassy state to a highly elastic state, providing thermodynamic conditions for the disorientation and rearrangement of the molecular chains.

[0077] During the stretching stage, the composite fibers in a highly elastic state enter the main stretching zone. The temperature of the stretching zone is set to 130℃ to 150℃. Axial tensile force is applied to the fibers using the difference in linear velocity between the front and rear traction rollers, with the total stretching ratio controlled within the range of 3.0 to 4.5 times. Under this tensile stress, the rigid molecular chains of polybutylene terephthalate resin and the molecular chains of the second spinning component are highly oriented along the fiber axis. Simultaneously, fibrous conductive materials dispersed in the matrix (such as vapor-grown carbon fibers or multi-walled carbon nanotubes) are deflected in the same direction as the matrix flow, with their long axis tending to be parallel to the fiber axis. Particulate conductive materials are driven by the stretching flow field and uniformly distributed between the elongated polymer chain segments.

[0078] The thermal stretching process reduces the diameter of the composite fiber from 100μm to 150μm in its initial state to 20μm to 50μm, significantly improving the fiber's breaking strength and initial modulus, and establishing the fiber's mechanical skeleton.

[0079] The composite fibers that have undergone hot stretching are in a high-energy state and have significant internal stress. If left untreated, they are prone to dimensional shrinkage during subsequent processing or use. Therefore, the stretched fibers are transported to a heat-setting chamber under constant tension for heat treatment.

[0080] The heat setting temperature is set to 160°C to 180°C, with the lower limit being higher than the heat stretching temperature to ensure that the polymer chain segments can relax to eliminate internal stress; the upper limit of the temperature is lower than the melting point (210°C to 225°C) of the second spinning component (polyether block amide resin or polyethylene glycol modified polyethylene terephthalate) to avoid the low melting point components from melting and sticking together or the interface structure being destroyed.

[0081] The heat setting time is controlled within the range of 30 to 60 seconds. During the heat setting process, polybutylene terephthalate resin undergoes secondary crystallization, with increased grain size and a more perfect lattice arrangement, forming stable physical cross-linking points. Simultaneously, the hard segment region of the second spinning component undergoes microcrystallization, locking in the morphology of the soft segment region. A tension of 0.5 cN / dtex to 1.5 cN / dtex is applied to the fiber using a tension control device, restricting the fiber's free shrinkage at high temperatures and forcing the molecular chains to maintain macroscopic dimensional stability while deorienting.

[0082] The heat setting process solidifies the interface morphology of the parallel composite structure under tension, while reserving a preset shrinkage potential between the polybutylene terephthalate side and the second spinning component side, thus storing structural potential energy for subsequent humidity-triggered self-curling behavior.

[0083] After the above thermomechanical treatment, a composite yarn is obtained. The composite yarn maintains a clear bicomponent side-by-side cross-section, with a tight bond between the two components, free of pores or peeling defects. The internal conductive filler is regularly arranged along the axial direction. In the dry state, the fibrous conductive material and the granular conductive material are separated by the polymer matrix and do not form a connected conductive network, thus maintaining the resistivity of the matrix.

[0084] Step S3 employs a regionalized weaving process, utilizing circular knitting technology to orient the composite yarn prepared in step S2 into specific areas of the knitted fabric. Through the structured implantation of the base yarn and composite yarn, step S3 constructs a knitted fabric that combines wearing comfort with moisture-responsive charge dissipation channels.

[0085] In this step, the weaving materials are divided into basic yarns, which serve as the fabric skeleton, and composite yarns, which serve as the functional carriers.

[0086] The composite yarn is the composite yarn prepared in step S2 and subjected to heat setting treatment. Before being put into weaving, the composite yarn is placed in an environment with a temperature of 20°C to 25°C and a relative humidity of 45% to 55% for 24 hours to equilibrate and eliminate winding stress.

[0087] The base yarn is selected from one or more of combed cotton yarn, viscose fiber yarn, polyester staple fiber yarn and polyamide filament yarn, depending on the application scenario and performance requirements of the product.

[0088] Combed cotton yarn is spun from cotton fibers with short fibers and impurities removed. It has a moisture regain of 8.5%, high absorbency and skin-friendliness, and can quickly absorb human sweat, providing a moist environment for composite yarns. However, it has a low elasticity recovery rate and is prone to dimensional swelling after absorbing moisture.

[0089] Viscose fiber yarn is made of regenerated cellulose fibers with a moisture regain of 11% to 13%. It has better moisture absorption and breathability than cotton fibers and a soft hand feel. However, it has a low wet modulus and its strength decreases significantly when wet, so tension control is necessary to prevent breakage.

[0090] Polyester staple fiber yarn is spun from polyethylene terephthalate staple fiber. It has high breaking strength, good abrasion resistance, and excellent dimensional stability, which can give the fabric good shape retention. Its moisture regain is only 0.4%, and it is prone to static electricity accumulation. Therefore, it needs to be used in conjunction with antistatic composite yarn.

[0091] Polyamide filament yarn, composed of polyamide 6 or polyamide 66 filaments, has high elongation at break, good abrasion resistance, and excellent elastic recovery ability, but its initial modulus is relatively low and the fabric stiffness is relatively weak.

[0092] Before entering the weaving process, the base yarn and composite yarn are combed and guided separately to ensure that the yarns are smooth and free of tangles and knots. The base yarn is waxed to control its dynamic coefficient of friction within the range of 0.15 to 0.18, and its winding density is controlled at 0.35 g / cm³. 3 Up to 0.45 g / cm 3 The range is adjusted to ensure uniformity of unwinding tension.

[0093] The knitting equipment used is a single- or double-sided circular knitting machine equipped with an electronic needle selection system and multiple independent yarn guide channels. The cylinder diameter of the circular knitting machine is 30 to 34 inches, and the machine size is 28 needles / 25.4 mm to 32 needles / 25.4 mm.

[0094] The weaving equipment includes a composite yarn channel equipped with a positive storage conveyor, with a conveying tension set to 1.5cN to 3.0cN to maintain the natural straightness of the composite yarn during the conveying process and prevent the pre-set curling potential energy inside the yarn from being released or destroyed prematurely due to mechanical stretching; and a basic yarn channel equipped with a conventional positive conveyor, with a conveying tension set to 4.0cN to 8.0cN to ensure the tightness and smoothness of the fabric structure.

[0095] In addition, by selecting sinking plates with different sinking depths, or by adjusting the pressure depth of the pressure cam, the loop length of the composite yarn and the base yarn can be differentiated during the looping process.

[0096] Based on the characteristics of static electricity accumulation and distribution in the human body, the weaving process divides the fabric plane into non-conductive and conductive areas. The non-conductive area corresponds to the main body of the garment, while the conductive area corresponds to the cuffs, hem, and collar, which are areas that frequently rub against the human body and are prone to charge accumulation.

[0097] In the non-conductive zone, the electronic needle selection system controls the composite yarn guide to exit the working position. The circular knitting machine only introduces the basic yarn and uses plain knit or double rib knit for continuous knitting. The non-conductive zone does not contain composite yarn, maintaining the lightweight feel and breathability of conventional knitted fabrics.

[0098] In the conductive zone, the electronic needle selection system drives the composite yarn guide nozzle to cut into the working position. Using padding or tuck weaving, the composite yarn is introduced into the base yarn weave.

[0099] In the yarn arrangement density control, the weaving cycle is set to insert one composite yarn for every 12 to 18 basic yarns woven, forming parallel conductive channels with a spacing of 3mm to 5mm in the weft direction of the fabric. This ensures effective charge capture and avoids localized hardening of the fabric due to excessive composite yarns.

[0100] The composite yarn forms a tuck-float structure on the knitting needles. Specifically, every 6 to 10 stitches, the knitting needles are controlled to perform a tuck operation, weaving the composite yarn and the base yarn together to form a tucked suspension arc. The tuck points act as physical anchors, preventing the composite yarn from shifting or unraveling on the inside of the fabric and ensuring that the composite yarn is stably positioned on the reverse side of the fabric (the side in contact with the skin). Simultaneously, between two tuck anchor points, the composite yarn does not participate in loop formation, forming a long float spanning 6 to 10 stitches, with a float length of 4mm to 6mm. This long float suspends on the inner surface of the fabric, providing free deformation space for the composite yarn to macroscopically self-crimp after moisture absorption, avoiding the rigid constraint of the base weave loops on the shrinkage behavior of the composite yarn.

[0101] The loop length is controlled by adjusting the bending depth. The loop length of the base yarn is set to 2.9mm to 3.1mm, and the loop length of the composite yarn is set to 3.2mm to 3.6mm. The longer loop length of the composite yarn, combined with the long float structure, makes the composite yarn loosely arched in the dry state, increasing the probability of contact with the skin; in the wet state, the composite yarn shrinks and curls, tightening the float, causing the fabric to generate a local inward micro-contraction force, further conforming to the skin and reducing contact resistance.

[0102] In this step, to prevent the composite yarn from triggering an unexpected moisture absorption reaction due to ambient humidity during the weaving process, the environment of the weaving workshop is strictly controlled.

[0103] The workshop temperature is maintained at 22°C to 26°C, and the relative humidity is controlled within the range of 50% to 60%, which is below the critical humidity threshold at which the second spinning component will experience significant volume expansion, ensuring that the composite yarn maintains structural and performance stability throughout the weaving process.

[0104] An airflow dust removal device is installed in the weaving area to blow the fabric looping area in a directional manner at a wind speed of 0.5m / s to 0.8m / s, removing fly shavings and cotton knots generated by the base yarn, and preventing insulating impurities from adhering to the surface of the composite yarn and affecting the conductive contact efficiency.

[0105] After knitting is completed, the knitted fabric is unwound using a loose take-up method. At this point, the composite yarns in the knitted fabric are distributed in a relaxed, uncurled state on the inner side of the conductive area.

[0106] Step S4 performs finishing on the knitted fabric prepared in step S3 to remove impurities introduced during the textile processing, eliminate internal residual stress, and fix the size and loop shape of the fabric. At the same time, it activates the latent crimp structure of the composite yarn through thermodynamic means, so that it has the free deformation space required for humidity response.

[0107] In this step, the knitted fabric is unfolded and introduced into a continuous flat-width washing machine in a loose state. The pretreatment process includes two stages: relaxation and swelling, and scouring and impurity removal.

[0108] During the relaxation and swelling stage, warm water at a temperature of 50°C to 60°C is injected into the first washing tank. The knitted fabric passes through the tank under the support of a tension-free conveyor belt, and the immersion time is 10 to 15 minutes. The warm water immersion causes the base yarn (such as cotton or viscose fiber) to swell naturally and open its pores; at the same time, it causes the second spinning component (polyether block amide resin or polyethylene glycol modified polyethylene terephthalate) in the composite yarn to undergo initial moisture absorption and relaxation. The relaxation and swelling stage releases the temporary elastic deformation caused by mechanical tension during weaving, preventing uncontrollable and severe shrinkage during subsequent high-temperature treatment.

[0109] In the scouring and impurity removal stage, a scouring solution containing nonionic surfactants and emulsifiers is prepared in the second washing tank. The temperature of the scouring solution is set to 70°C to 80°C, and the pH value is controlled within a neutral range of 6.5 to 7.5. The fabric is treated in the scouring solution for 15 to 20 minutes. The scouring and impurity removal stage removes hydrophobic impurities such as waxes, oils, pectin, and cottonseed hulls that are applied in step S3 to ensure smooth weaving. This impurity removal treatment improves the hydrophilicity of the fabric, ensuring that moisture can quickly penetrate to the surface of the composite yarn during subsequent use, triggering the humidity response mechanism.

[0110] After scouring, the knitted fabric is rinsed twice with clean water until the pH value of the cleaning solution is neutral.

[0111] After rinsing, the fabric is mechanically dehydrated in a rolling mill or centrifugal dehydrator to control the liquid content to within the range of 60% to 70%, and then pre-dried in a loose dryer.

[0112] Pre-drying employs a hot air penetration method, with the air temperature set at 90℃ to 110℃ and the air velocity at 1.5m / s to 2.0m / s. During the drying process, the conveyor belt operates at a speed slightly higher than the feeding speed, creating an overfeed of 5% to 10%, allowing the fabric to freely shrink under the influence of hot air, further reducing the warp shrinkage rate. At the end of pre-drying, the fabric moisture content is controlled within the range of 5% to 8%.

[0113] After pre-drying, the fabric enters a tenter frame for high-temperature setting to fix the fabric width, weight, and loop structure stability, while also determining the morphology of the two-component structure of the composite yarn.

[0114] The setting temperature is set to 170℃ to 185℃, higher than the hot stretching temperature in step S2 and also higher than the glass transition temperature of polybutylene terephthalate (PET), ensuring that the polymer molecular chain segments can undergo disorientation and rearrangement, eliminating internal stress. Simultaneously, this temperature is lower than the melting point of the second spinning component, preventing the composite yarn from melting and sticking together or the cross-sectional structure from collapsing. The setting time is controlled within the range of 30s to 45s. The fabric width is controlled according to the finished product specifications. The overfeed rate is set to 10% to 20%, a higher overfeed rate keeping the warp direction of the fabric relaxed.

[0115] Under high temperature and overfeed conditions, thermal stress is generated between the second spinning component and the matrix (polybutylene terephthalate) of the first spinning component in the composite yarn due to a slight difference in their thermal shrinkage rates. As the fabric relaxes in the warp direction, the long floats of the composite yarn between the tuck anchor points undergo pre-curling deformation, forming a microscopic three-dimensional helical structure. After heat setting, the fabric is rapidly cooled by forced cold air (20°C to 30°C), fixing this microscopic helical structure and providing geometric space for further macroscopic curvature of the second spinning component after moisture absorption, thus preventing the yarn from being locked by the fabric structure.

[0116] To improve the feel and moisture absorption rate of the fabric, a hydrophilic softening finish is applied after the fabric has been set. Hydrophilic silicone softeners or fatty acid amide softeners are selected as finishing agents. Softeners with strong film-forming properties or hydrophobic properties are strictly prohibited, as they may form an insulating or water-blocking layer on the surface, affecting ion migration and moisture penetration.

[0117] Finishing is performed using either padding or spraying. If padding is used, the softener concentration is controlled at 10 g / L to 20 g / L, and the roll-off rate is controlled at 70% to 80%. The finished fabric is then placed in an oven for secondary drying at a temperature of 130℃ to 140℃ for 60 to 90 seconds.

[0118] The antistatic knitted fabric is prepared through the above step S4.

[0119] An antistatic knitted fabric, obtained by processing the above-mentioned antistatic knitted fabric, can be designed as a single-layer fabric structure or a double-layer fabric structure. The processing methods, interlayer relationships and composite yarn distribution states of the two structures are different, and the specific explanations are as follows.

[0120] This single-layer antistatic knitted fabric is directly processed from an antistatic knitted fabric based on charge accumulation and directional guidance. During processing, the original structural integrity of the antistatic knitted fabric based on charge accumulation and directional guidance is maintained, ensuring that the side containing the composite yarn is close to the human skin; that is, the composite yarn is located on the inner side of the single-layer antistatic knitted fabric. In this single-layer structure, the composite yarn is in direct contact with the human skin, allowing it to sense changes in humidity on the body surface and in the surrounding environment and adjust its conductivity accordingly. Simultaneously, it captures static electricity generated on the inner side of the garment during human activity, achieving static electricity conduction and diffusion through the directional conductive path constructed by the composite yarn. This static electricity conduction and diffusion process requires no additional medium.

[0121] The double-layer antistatic knitted fabric employs a composite structure of an inner composite layer and an outer covering layer. The inner composite layer is an antistatic knitted fabric based on charge accumulation and directional guidance, with the composite yarns of the inner composite layer facing outwards, i.e., towards the outer covering layer. The outer covering layer is a conventional textile fabric, including cotton or polyester blends. During processing, the inner composite layer and the outer covering layer are fixed using edge-binding, lamination, or sewing techniques. After fixing, the composite yarns are completely located between the inner composite layer and the outer covering layer, and are not exposed on the outer surface of the double-layer antistatic knitted fabric.

[0122] The specifications of the raw materials and reagents involved in all the following examples and comparative examples are as follows:

[0123] Polybutylene terephthalate (PBT) resin, using semi-crystalline thermoplastic polyester chips with a melting point of 225℃ and an intrinsic viscosity of 0.9 dL / g as the matrix of the first spinning component;

[0124] Polyether block amide resin (PEBA): A block copolymer with a melting point of 215℃ and a hardness of 40D, composed of nylon 12 hard segments and polytetrahydrofuran soft segments, was selected as the second spinning component.

[0125] Fibrous conductive material: Vapor-grown carbon fiber (VGCF) with an average diameter of 150 nm, an average length of 15 μm, and a volume resistivity of 1.0 × 10⁻⁶ -4 Ω·m;

[0126] Particulate conductive material: Conductive carbon black with an average primary particle size of 30 nm and a specific surface area (BET) of 900 m² is selected. 2 / g, with an oil absorption value (DBP) of 300ml / 100g;

[0127] Base yarn: Selected combed cotton yarn with a linear density of 32 tex, which is waxed and has a dynamic friction coefficient of 0.16;

[0128] Softener: A weakly cationic hydrophilic silicone softening emulsion with a solid content of 30% is selected.

[0129] Example 1: This example describes the preparation of an antistatic knitted fabric based on charge accumulation and directional guidance. The specific preparation method is as follows:

[0130] S1: A mixture of fibrous conductive material and granular conductive material in a mass ratio of 1:4 with polybutylene terephthalate resin, wherein the total mass percentage of conductive filler is 5%. The mixture is added to a twin-screw extruder and melt-blended at a die head temperature of 235℃ and a screw speed of 250 r / min, then extruded and granulated to obtain the first spinning component. The first spinning component and polyether block amide resin are separately added to a dual-channel composite spinning device, with the channel temperature of the first spinning component set at 235℃ and the channel temperature of the polyether block amide resin set at 225℃. The two components are combined at a mass flow rate ratio of 50:50 in a parallel spinneret and extruded through the spinneret orifice. The extruded melt stream is cooled and solidified by a side-blowing airflow at a temperature of 25℃ and a wind speed of 0.8 m / s to obtain a composite fiber with a parallel composite structure.

[0131] S2: The nascent composite fibers are introduced into a continuous hot stretching device, preheated at 90°C, and then stretched in a 140°C stretching zone with a stretch ratio set to 3.5 times. Subsequently, heat setting is performed at a tension of 1.0 cN / dtex, a setting temperature of 170°C, and a time of 45 seconds to obtain the composite yarn.

[0132] S3: The composite yarn and base yarn are introduced into a 30-inch, 28-gauge / 25.4mm single-jersey circular knitting machine. In the conductive area of ​​the fabric where static electricity easily accumulates (cuff area), the composite yarn is introduced using a tuck weaving technique. The knitting cycle in the conductive area is set to insert one composite yarn for every 12 basic yarn runs. Based on the cycle ratio, the composite yarn accounts for 7.69% of the total number of runs in the conductive area, corresponding to a mass percentage of approximately 7.7%. The composite yarn forms a 4mm long float between the tuck points. Only the base yarn is knitted in the non-conductive areas. The knitting workshop temperature is 24℃, and the relative humidity is 55%. The resulting fabric is a knitted greige.

[0133] S4: The knitted fabric is fed into a flat-width washing machine and relaxed in 55℃ warm water for 15 minutes, followed by treatment in a scouring solution at 75℃ for 20 minutes. After rinsing, it is dehydrated to a moisture content of 65%. It is then pre-dried in 100℃ hot air to a moisture content of 6%. Subsequently, it enters a tenter frame heat setter, with the setting temperature set at 175℃ for 40 seconds and an overfeed rate of 15%. After setting, a hydrophilic silicone softener (concentration 15g / L) is applied by padding, and a second drying is performed at 135℃ for 90 seconds to obtain the antistatic knitted fabric.

[0134] Example 2: In this example, unlike Example 1, the weaving cycle ratio of the conductive zone is changed in step S3. It is set to insert one composite yarn for every 16 basic yarns woven. Based on the cycle ratio, the proportion of composite yarns in the conductive zone is 5.88%, corresponding to a mass proportion of approximately 5.9%. In step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component remains 1:4. The remaining raw material specifications and preparation process parameters are consistent with Example 1.

[0135] Example 3: In this example, unlike Example 1, the weaving cycle ratio of the conductive zone is changed in step S3. It is set to insert one composite yarn for every eight basic yarns woven. Based on the cycle ratio, the proportion of composite yarns in the conductive zone is 11.11%, corresponding to a mass proportion of approximately 11.1%. In step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component remains 1:4. The remaining raw material specifications and preparation process parameters are consistent with Example 1.

[0136] Example 4: In this example, unlike Example 1, in step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component is changed to 1:3. In step S3, the weaving cycle ratio of the conductive zone is maintained at 1 composite yarn inserted for every 12 basic yarns woven, with the composite yarn accounting for approximately 7.7% of the total mass. The remaining raw material specifications and preparation process parameters remain the same as in Example 1.

[0137] Example 5: In this example, unlike Example 1, in step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component is changed to 1:5. In step S3, the weaving cycle ratio of the conductive zone is maintained at 1 composite yarn inserted for every 12 basic yarns woven, with the composite yarn accounting for approximately 7.7% of the total mass. The remaining raw material specifications and preparation process parameters remain the same as in Example 1.

[0138] Example 6: In this example, unlike Example 1, in step S3, the weaving cycle ratio of the conductive zone is set to insert one composite yarn for every 16 basic yarns woven, with the composite yarn accounting for approximately 5.9% of the total mass. Meanwhile, in step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component is set to 1:3. All other raw material specifications and preparation process parameters remain the same as in Example 1.

[0139] Example 7: In this example, unlike Example 1, in step S3, the weaving cycle ratio of the conductive zone is set to insert one composite yarn for every 16 basic yarns woven, with the composite yarn accounting for approximately 5.9% of the total mass. Meanwhile, in step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component is set to 1:5. All other raw material specifications and preparation process parameters remain the same as in Example 1.

[0140] Example 8: In this example, unlike Example 1, in step S3, the weaving cycle ratio of the conductive zone is set to insert one composite yarn for every eight basic yarns woven, with the composite yarn accounting for approximately 11.1% of the total mass. Meanwhile, in step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component is set to 1:3. All other raw material specifications and preparation process parameters remain the same as in Example 1.

[0141] Example 9: In this example, unlike Example 1, in step S3, the weaving cycle ratio of the conductive zone is set to insert one composite yarn for every eight basic yarns woven, with the composite yarn accounting for approximately 11.1% of the total mass. Meanwhile, in step S1, the mass ratio of fibrous conductive material to granular conductive material in the first spinning component is set to 1:5. All other raw material specifications and preparation process parameters remain the same as in Example 1.

[0142] Comparative Example 1: This comparative example prepared a conventional antistatic fabric. The specific preparation method is as follows:

[0143] S1: Fibrous conductive material and granular conductive material are weighed at a mass ratio of 1:4 and mixed with polybutylene terephthalate resin, wherein the total mass percentage of conductive filler is 5%. The mixture is added to a screw extruder and melt-blended at a die head temperature of 235℃. A single-component melt spinning process is used, and the melt is extruded through a single-hole spinneret. The extruded melt stream is cooled and solidified by side-blowing air at a temperature of 25℃ and a wind speed of 0.8m / s to obtain single-component conductive fibers.

[0144] S2: The single-component conductive fiber is introduced into a continuous hot stretching device, preheated at 90°C, and then placed in a stretching zone at 140°C with a stretching ratio set to 3.5 times. Subsequently, it is heat-set at a tension of 1.0 cN / dtex, a setting temperature of 170°C, and a time of 45 s to obtain the single-component conductive yarn.

[0145] S3: The single-component conductive yarn is introduced into a 30-inch, 28-gauge / 25.4mm single-sided circular knitting machine along with the base yarn. A full-width blending process is used, meaning the conductive yarn is introduced into all areas of the fabric, without distinguishing between conductive and non-conductive areas. The knitting cycle is set to insert one single-component conductive yarn for every 12 passes of base yarn. During loop formation, the single-component conductive yarn and base yarn are fed synchronously and form the same loop structure. The knitting workshop temperature is 24℃, and the relative humidity is 55%. The resulting fabric is an antistatic greige.

[0146] S4: The antistatic fabric greige is fed into a flat-width washing machine and washed in 55℃ warm water for 15 minutes, followed by treatment in a 75℃ scouring solution for 20 minutes. After rinsing, it is dehydrated and dried in 100℃ hot air until the moisture content is 6%. It then enters a tenter frame heat setter, with the setting temperature set at 175℃ for 40 seconds. After heat setting, it is cooled and wound, and a hydrophilic silicone softener is applied to obtain the antistatic fabric.

[0147] Experimental Example 1: From the finished fabrics prepared in Examples 1 to 9 and Comparative Example 1, test samples of 300mm × 300mm were randomly cut. For the example samples, the cutting location covered the electrostatically charged conductive area containing the composite yarn (cuff area); for the comparative sample, the cutting location was arbitrary. After cutting, all samples were conditioned in a standard atmospheric environment (temperature 20℃±2℃, relative humidity 35%±5%) for 48 hours to eliminate the influence of thermal history and unstable moisture regain during processing, and the following tests were performed:

[0148] 1. Humidity-responsive surface resistivity test: According to GB / T 24249-2009, the surface resistivity of the sample under different humidity conditions was measured using a surface resistivity tester (test voltage 100V). In the dry state test, the conditioned sample was placed in an environmental control chamber with a set temperature of 25℃ and relative humidity of 30%. After the sample equilibrated for 24 hours, the electrode was placed on the conductive area containing the composite yarn for testing, and the surface resistivity data (denoted as ) was recorded. In the humidity test, the relative humidity of the environmental control chamber was adjusted to 85% (simulating a high-humidity, sweating environment), and the temperature was maintained at 25℃. After the sample equilibrated for 24 hours, the test was conducted at the same location, and the surface resistivity data (denoted as ) was recorded. ).

[0149] 2. Triboelectric Charge Test: The test was conducted using the roller friction method according to GB / T 12014-2019. The test environment was set to a relative humidity of 30% (simulating a dry, electrifying environment). The sample was rubbed against a standard nylon friction cloth inside the roller for 15 minutes. Immediately after the friction was completed, the sample was placed into a Faraday cage, and the amount of charge on the sample was measured and recorded.

[0150] 3. Electrostatic Dissipation Time Test: According to SJ / T 10694-2022, a non-contact electrostatic dissipation tester was used. The test environment was set to a relative humidity of 30%. An initial voltage of ±5000V was applied to the sample, and the time required for the voltage to decay from 5000V to 500V (i.e., decay to 10%) was measured.

[0151] The results are shown in the table below:

[0152] Table 1 Comparison of Experimental Results

[0153]

[0154] The weaving cycle ratio determines the distribution density and spatial freedom of the composite yarns in the fabric. Experimental data shows that as the weaving cycle ratio is adjusted from 16:1 (low density) to 12:1 (medium density), the wetted surface resistivity (… The resistance is significantly reduced; however, when the density is further increased to 8:1 (high density), the resistance rises again. When the weaving cycle is 16:1 (Example 2), the spacing of the composite yarns in the weft direction of the fabric is large. Although a single composite yarn can curl and deform after absorbing moisture, due to the excessively sparse macroscopic distribution, it is difficult to form effective charge-induced coupling between the yarns, resulting in physical breaks in the overall electrostatic dissipation path of the fabric. At this time, the charge mainly relies on the transmission of individual yarns and cannot form a regional conductive network, therefore... The density is relatively high. When the weaving cycle is 8:1 (Example 3), the composite yarns are arranged too tightly. Although the number of conductive channels theoretically increases, sufficient space is needed for the hygroscopic expansion of the second spinning component in a wet state to achieve macroscopic crimping. The excessively high yarn density causes spatial steric hindrance in the floating segments between the loop points during three-dimensional helical crimping, with adjacent yarns squeezing each other and limiting the full unfolding of the crimp deformation. This spatial constraint weakens the physical compression effect of axial shear stress on the internal conductive filler, preventing the contact resistivity from being reduced to a minimum. On the contrary, it is higher than the medium-density group. When the weaving cycle is 12:1 (Example 1), the distribution density and deformation space of the composite yarn reach the optimal balance, ensuring both a sufficient number of conductive channels to cover the conductive area and providing ample free volume for the moisture absorption and self-curling of each composite yarn. The composite yarn can fully unfold its three-dimensional helical structure, maximizing the conversion of moisture swelling stress into compressive force on the internal conductive core layer, thereby achieving the lowest... .

[0155] The mass ratio of conductive filler determines the connectivity and integrity of the microscopic conductive skeleton within the composite yarn. Experimental data shows that as the proportion of particulate conductive material (conductive carbon black) increases, the conductivity initially improves and then deteriorates. In the low-filling system with a mass ratio of 1:3 (Example 4), the amount of particulate conductive carbon black is insufficient to completely fill the microscopic voids between the linear skeletons constructed from vapor-grown carbon fibers. Electrons face a large tunneling barrier when transporting between carbon fibers, resulting in a large number of non-connected dead zones in the internal conductive network. Even with externally applied wet compressive force, the limited number of effective pathways due to insufficient conductive nodes leads to high resistivity. In the high-filling system with a mass ratio of 1:5 (Example 5), excessive nanoscale carbon black particles agglomerate in the polymer matrix, forming isolated large aggregates. These aggregates not only fail to contribute effective conductivity but also become electron scattering centers. More importantly, during the thermal stretching process in step S2, these large aggregates act as stress concentration points during matrix rheology, easily causing fractures or micro-damage to the long-range conductive skeleton of the vapor-grown carbon fibers. The defects in this microstructure negate the advantages of high filler content, resulting in the resistivity failing to reach its extreme value. In the optimized system with a mass ratio of 1:4 (Example 1), the conductive carbon black precisely fills the overlap points between the vapor-grown carbon fibers, ensuring the smooth flow of long-range electron transport while using particulate fillers to repair the breaks between the skeletons, thus achieving optimal connectivity of the micro-conductive network.

[0156] At the microscopic level, the 1:4 filler ratio constructs a high-quality, potentially conductive network in a critical percolation state, exhibiting extremely high sensitivity to external stress. At the macroscopic level, the 12:1 braiding cycle allows the composite yarn to generate maximum hygroscopic self-curling, providing a strong physical compression field. When both conditions are simultaneously met, the strong macroscopic compression field acts on the highly sensitive microscopic conductive network, causing a sudden decrease in the average spacing between conductive fillers and an exponential increase in contact nodes. If the microscopic network is defective (e.g., 1:3 or 1:5), the strong compression force cannot repair the open circuit or may exacerbate the destruction of aggregates; if the macroscopic compression force is limited (e.g., 8:1 or 16:1), even a perfect microscopic network cannot complete the phase transition from a high-resistivity state to a low-resistivity state. Only under the specific parameter combination of Example 1 can the macroscopic deformation energy and microscopic structure energy achieve energy coupling, thereby obtaining superior antistatic performance beyond single-variable optimization.

[0157] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing an antistatic knitted fabric based on charge accumulation and directional guidance, characterized in that, Includes the following steps: S1: The first spinning component and the second spinning component are melted separately and co-extruded by melt spinning to form a composite fiber with a parallel composite structure; the first spinning component includes a matrix resin and a conductive filler, and the conductive filler is a fibrous conductive material and a granular conductive material with a mass ratio of 1:3 to 1:5; the second spinning component is a polyether block amide resin or polyethylene glycol modified polyethylene terephthalate; S2: The composite fibers are subjected to stretching and heat setting treatments in sequence to obtain composite yarn; S3: The fabric plane is divided into non-conductive and conductive areas. Basic yarns are used for weaving in the non-conductive areas, and composite yarns are introduced in the conductive areas using tuck weaving or padding. This allows the composite yarns to form a tuck-float structure in the conductive areas, which is then woven together with the basic yarns to form a knitted fabric. The yarn arrangement density in the conductive areas is 1 composite yarn inserted for every 8 to 16 basic yarns woven. The basic yarns are selected from one or more of combed cotton yarn, viscose fiber yarn, polyester staple fiber yarn, and polyamide filament yarn. S4: Perform finishing on the knitted fabric to obtain an antistatic knitted fabric; In step S1, the matrix resin of the first spinning component is polybutylene terephthalate resin; the fibrous conductive material is selected from one or more of vapor-grown carbon fibers, multi-walled carbon nanotubes, and conductive carbon fibers; the particulate conductive material is selected from one or more of conductive carbon black, graphene microsheets, and carbon aerogel particles. In step S2, the stretching process includes a preheating stage and a stretching stage; the preheating temperature in the preheating stage is 80°C to 100°C, the stretching zone temperature is 130°C to 150°C, and the total stretching ratio is 3.0 to 4.5 times; the heat setting temperature is 160°C to 180°C, the processing time is 30s to 60s, and a tension of 0.5cN / dtex to 1.5cN / dtex is applied to the fiber.

2. The preparation method according to claim 1, characterized in that, In step S1, the melt spinning adopts an independent temperature-controlled dual-channel composite spinning equipment, and the mass flow ratio of the first spinning component to the second spinning component is set to 40:60 to 60:40; the melts of the first spinning component and the second spinning component converge at the parallel composite spinneret to form a parallel melt stream, which is cooled and solidified by side blowing to form the composite fiber.

3. The preparation method according to claim 1, characterized in that, In step S4, the finishing process includes pretreatment, pre-drying, and stretching heat setting. The pretreatment includes relaxation and swelling in warm water at 50°C to 60°C, and refining and impurity removal in a refining solution at 70°C to 80°C. The pre-drying is carried out by hot air penetration at a temperature of 90°C to 110°C, resulting in an overfeed of 5% to 10%.

4. The preparation method according to claim 3, characterized in that, In step S4, the temperature for the stretching heat setting is set to 170°C to 185°C, the time is set to 30s to 45s, and the overfeed rate is set to 10% to 20%.

5. An antistatic knitted fabric based on charge accumulation and directional guidance, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 4.

6. An antistatic knitted fabric, characterized in that, It is obtained by processing the antistatic knitted fabric as described in claim 5.

Images