Knitted fabric weaving method with gradient density structure

Abstract

The invention discloses a knitting method of knitted fabric with a gradient density structure, and relates to the technical field of textile, and the knitting method comprises the following steps: collaboratively designing raw material components and a multi-layer tissue structure, and constructing a physical model of density gradient in the thickness direction; configuring equipment process parameters, and establishing a mapping relation; controlling all layers of raw materials to execute integrated weaving forming to form a multi-layer structure with a continuous interface; a sensor is used for monitoring tension fluctuation in real time and adjusting the yarn feeding amount in a closed-loop mode; and finally carrying out heat setting treatment. The surface layer fine denier fibers, the middle layer high-elasticity monofilaments and the inner layer coarse denier yarns are matched, and capillary pressure difference is generated by combining asymmetric pore distribution formed by a composite tissue. The efficient one-way moisture guiding and heat and moisture management performance is achieved, the structural stability and durability are enhanced, the process is environmentally friendly, and the production efficiency and the product consistency are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically relating to a method for weaving knitted fabrics with a gradient density structure. Background Technology

[0002] With the deep integration of the textile industry and materials science, functional knitted fabrics are increasingly widely used in sports and outdoor activities, healthcare, and special protective applications. As a core indicator for improving clothing comfort, the heat and moisture transfer properties of fabrics directly affect the balance of the human body's microenvironment. To achieve efficient sweat management, researchers have modified fiber arrangement and fabric geometry to endow fabrics with moisture-wicking, one-way moisture-wicking, and dynamic thermal regulation functions, which has become an important direction for innovation in modern textile technology.

[0003] Among them, knitted fabrics with gradient density structures utilize the differentiated distribution of physical structures to create a capillary pressure gradient from the inside out, which is a key pathway to achieving unidirectional moisture wicking. These fabrics typically involve a multi-layered composite design, precisely controlling the differences in porosity, fiber density, and wettability between the inner and outer layers to promote rapid migration and diffusion of moisture from the skin contact surface to the outer layer. In high-intensity exercise and complex environments, the gradient density structure not only keeps the skin dry but also maintains long-lasting functional performance through structural stability.

[0004] However, existing technologies for constructing gradient density structures often employ multi-layer fabric composites or chemical finishing methods, resulting in insufficient interlayer bonding and a high risk of peeling, severely impacting the fabric's washability and service life. Simultaneously, traditional weaving processes, when handling heterogeneous fiber combinations, often lack dynamic and coordinated control of yarn feed and weaving tension, making it difficult to precisely define the porosity gradient along the thickness direction during a single forming process. Furthermore, due to the relatively simple fiber composition and lack of hierarchical nesting in the weave structure, existing fabrics inherently contradict each other in achieving both high strength and quick-drying properties with softness and moisture absorption, failing to meet the stringent requirements of high-quality functional fabrics for structural continuity and performance versatility. Summary of the Invention

[0005] The purpose of this invention is to provide a method for weaving knitted fabrics with a gradient density structure, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for weaving a knitted fabric with a gradient density structure includes the following specific steps: Step 1: Collaborative design of raw material combination and multi-layer structure: Based on preset moisture absorption and wicking performance indicators, the raw material components of the face layer, middle layer, and inner layer are selected respectively, and a composite knitted structure including yarn-filling structure and weft-insertion structure is designed to construct a preliminary physical model with a density gradient in the thickness direction; Step 2: Configuration of weaving equipment process parameters: Based on the physical model designed in Step 1, the yarn feeding speed of the yarn feeding device, the dynamic tension of the knitting mechanism, and the loop length of the loop-forming system are set segment by segment to establish the mapping relationship between raw material characteristics and process parameters; Step 3: Execution Integrated weaving and forming: Start the knitting equipment and control the surface layer, middle layer and inner layer materials to be woven synchronously according to the preset structure cycle, directly forming a multi-layer integrated fabric structure with a continuous interface in the weaving process; Step 4 Dynamic monitoring and closed-loop adjustment: Use online monitoring sensors to collect yarn tension fluctuation data in real time during the weaving process, and correct the yarn feed amount in real time through feedback control loop to ensure the uniformity of the gradient density structure; Step 5 Post-processing and finished product inspection: Perform heat setting treatment on the woven knitted fabric, and detect its porosity distribution and unidirectional moisture conductivity index in the thickness direction to verify the effectiveness of the gradient density structure.

[0007] Preferably, in step 1, the surface material is selected from fine denier chemical fiber filaments, and the fineness of the filaments is set within a preset fineness range. The chemical fiber filaments specifically include polyester fibers or polyamide fibers. The high-density surface structure is formed by the close arrangement of high-count filaments, which gives the fabric surface excellent strong support and quick-drying properties.

[0008] Preferably, in step 1, the inner layer material is selected from coarse denier yarn or blended yarn, and its linear density is set within a preset linear density range. The blended yarn is made by blending combed cotton fiber and modified polyester fiber in a predetermined proportion. By utilizing the hydrophilicity of natural fibers and the moisture-wicking properties of modified fibers, a loose inner layer structure with high moisture absorption capacity is constructed.

[0009] Preferably, in step 1, the middle layer material serves as the connecting link between the surface layer and the inner layer. It is made of highly elastic monofilament with a diameter set within a preset diameter range. The surface layer and the inner layer are tightly locked together through specific weaving points to ensure that the multilayer structure will not experience interlayer displacement or peeling when subjected to external tensile forces.

[0010] Preferably, in step 1, the composite knitting structure is woven using a double-sided circular knitting machine. The outer layer uses a plain knitting structure with added yarn, and the inner layer uses a combination structure of tuck knitting and weft insertion knitting. By changing the distribution density of the tuck knitting points, an asymmetrical pore distribution is formed inside the fabric, thereby generating a capillary pressure difference from the inside to the outside.

[0011] Preferably, in step 2, the setting of the yarn feeding amount follows the principle of gradient decrease. The yarn feeding speed of the inner layer is set to the first preset yarn feeding speed, the yarn feeding speed of the middle layer is set to the second preset yarn feeding speed, and the yarn feeding speed of the surface layer is set to the third preset yarn feeding speed. The precise control of the coil size is achieved through differentiated yarn feeding speeds.

[0012] Preferably, in step 2, the control of weaving tension is achieved through an electronic weft feeder. The dynamic tension of the inner layer yarn is set to a first preset tension value, the tension of the middle layer connecting yarn is set to a second preset tension value, and the tension of the outer layer filament is set to a third preset tension value, so as to ensure that the raw materials with different properties maintain a stable geometric shape during the looping process.

[0013] Preferably, in step 2, the coil length of the looping system is achieved by adjusting the needle depth, with the inner coil length set to a first preset length and the outer coil length set to a second preset length, thereby creating a significant density gradient in the fabric thickness direction through the significant difference in coil length.

[0014] Preferably, in step 3, the needle bed spacing of the knitting equipment is set to a preset needle spacing, and a multi-path yarn feeding method is adopted. Each yarn feeding system is equipped with an independent tension compensation device to ensure that the raw materials of the surface layer, middle layer and inner layer can be accurately interwoven in the same loop cycle during operation.

[0015] Preferably, in step 4, the online monitoring sensor is a piezoelectric tension sensor, the sampling frequency is set to a preset sampling frequency, the sensor transmits the collected tension signal to the central processing unit, the central processing unit calculates the correction value of the yarn feeding amount through the proportional-integral-derivative control algorithm, and drives the servo motor to adjust the speed of the yarn feeding disc, and the adjustment accuracy reaches the preset accuracy value.

[0016] Preferably, in step 5, the heat setting treatment is performed on a tenter frame, the setting temperature is set within a preset temperature range, and the processing time is set within a preset time period. The heat energy causes the chemical fibers to physically shrink, further solidifying the gradient density structure and improving the dimensional stability of the fabric.

[0017] Preferably, the finished product testing process includes evaluating the fabric using a liquid moisture management tester. The test indicators include immersion time, water absorption rate, maximum immersion radius, diffusion speed, and unidirectional moisture conduction index. The unidirectional moisture conduction index is required to meet a preset moisture conduction threshold, and the overall moisture management capability reaches a predetermined level standard.

[0018] Preferably, the porosity distribution of the gradient density structure in the thickness direction exhibits a non-linear change. The porosity of the inner layer is set within a first preset porosity range, the porosity of the middle layer is set within a second preset porosity range, and the porosity of the surface layer is set within a third preset porosity range. This structural arrangement from loose to dense generates a strong Laplace pressure difference, which promotes the spontaneous migration of water to the outer layer.

[0019] Preferably, the knitted fabric weaving method with gradient density structure further includes temperature and humidity control of the weaving environment, with the workshop temperature maintained within a preset ambient temperature range and the relative humidity maintained within a preset ambient humidity range, in order to reduce the impact of static electricity on the fine denier filament weaving process and ensure the smoothness of the fabric surface.

[0020] Preferably, the method achieves the formation of specific functional areas on the fabric surface by adjusting the arrangement frequency of the weft yarns, including a high-breathability area and a high-support area. The porosity of the high-breathability area is increased by a predetermined ratio compared with the conventional area, in order to meet the heat dissipation needs of different parts of the human body.

[0021] Preferably, the surface material is subjected to cold plasma treatment before weaving, with the treatment power set within a preset power range and the treatment time set to a preset treatment duration, in order to improve the surface roughness and hydrophilic group content of the fiber, and further enhance the surface layer's ability to diffuse and evaporate moisture.

[0022] Preferably, silver ion modified fibers with antibacterial function are added to the inner layer raw material, and the addition ratio is set within a preset ratio range. Through uniform distribution in the weaving process, the finished fabric can obtain long-lasting antibacterial and deodorizing performance while having a gradient density structure.

[0023] Preferably, a fully automatic fabric doffing device is used in the weaving process. The diameter of the fabric roll is monitored by an infrared sensor. When the diameter reaches a preset diameter threshold, the system automatically performs fabric cutting and roll changing actions. The repeatability positioning accuracy reaches the preset accuracy range, which significantly improves the automation level of the production line.

[0024] Preferably, the composite knitted structure also incorporates a loop suspension structure, which reduces the number of loops in specific areas to form a tiny air layer. This air layer not only increases the fabric's warmth retention but also acts as a buffer zone for moisture migration, regulating the residence time of moisture in the gradient density structure.

[0025] Preferably, the mapping relationship between the raw material characteristics and the process parameters is realized by establishing a mathematical model. This model comprehensively considers the friction coefficient, elastic modulus and bending stiffness of the yarn, and predicts the fabric density distribution under different parameter combinations through numerical simulation, with the prediction error controlled within a preset error range.

[0026] Preferably, the total weight of the knitted fabric produced by the method is controlled within a preset weight range, the thickness is controlled within a preset thickness range, and both the longitudinal shrinkage rate and the transverse shrinkage rate are less than or equal to a preset shrinkage rate threshold, thus meeting the requirements for high-performance sports fabrics.

[0027] Preferably, the cross-sectional shape of the surface material is an irregular cross-section. The micro-grooves formed by the irregular cross-section generate additional capillary force, which, together with the gradient density structure, accelerates the emission of moisture into the atmosphere.

[0028] Preferably, the spacing between the interlacing points of the middle layer connecting filaments is set within a preset spacing range. By optimizing the arrangement of the interlacing points, the obstruction to the vertical water transfer path is minimized while ensuring the interlayer bonding force.

[0029] Preferably, the weaving equipment is also equipped with an automatic breakage and stop device. The sensing sensitivity is set to a preset response time. When any raw material breaks or has abnormal tension, the equipment immediately stops operating and issues an audible and visual alarm signal to ensure that the continuity of the gradient density structure is not disrupted.

[0030] Preferably, the mechanism for achieving the one-way moisture-wicking function is that the liquid water in the inner large-pore structure is drawn to the middle layer under capillary pressure, and then transferred from the middle layer to the small-pore structure of the surface layer. Due to the high density of the surface layer, the water rapidly diffuses laterally in the surface layer, greatly increasing the evaporation area, thereby achieving the technical effect of moisture absorption and quick drying.

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention constructs a gradient density structure directly during the weaving process, utilizing a composite design of yarn-adding and weft-inserting structures to weave different functional raw materials into a single unit. This integrated molding technology solves the problem of weak interlayer bonding in traditional multi-layer composite fabrics, avoiding peeling and delamination during long-term wear and repeated washing. After multiple standard washes, the knitted fabric prepared by this invention maintains an interlayer strength retention rate of over a predetermined percentage, exhibits no significant attenuation in unidirectional moisture wicking performance, and significantly extends the service life of functional fabrics.

[0032] (2) By precisely controlling the yarn feed, weaving tension, and loop length, this invention successfully constructs a porosity gradient from the inside to the outside in the fabric thickness direction. This physical structure, from loose to dense, generates a strong capillary pressure difference, enabling the directional conduction of liquid moisture. The unidirectional moisture-wicking index of this invention meets the preset index, the time for moisture to penetrate from the inner layer to the outer layer is shortened to within the preset time threshold, and the diffusion area of ​​the outer layer is significantly improved compared to traditional double-sided fabrics. This allows the wearer's skin surface to remain dry even when sweating profusely during exercise, significantly improving the thermal and moisture comfort of the clothing.

[0033] (3) The method of the present invention does not require complex chemical finishing or multiple processing steps, and the construction of a high-performance gradient density structure can be completed on a single knitting machine. Through the synergistic design of raw materials and fabric, the cumbersome bonding, lamination and coating steps in traditional processes are reduced, and production efficiency is significantly improved. At the same time, since the moisture-wicking function is not achieved by relying on chemical auxiliaries, the method of the present invention is more environmentally friendly, reduces production costs and processing pressure, and is in line with the trend of sustainable development in the textile industry.

[0034] (4) By utilizing online monitoring sensors and a closed-loop feedback control system, this invention achieves dynamic correction of key process parameters during the weaving process. This highly automated control method effectively compensates for the effects of yarn tension fluctuations and raw material differences, ensuring the high uniformity of the gradient density structure throughout the entire roll of fabric. By establishing a mathematical model of raw material characteristics and process parameters, digital management of product quality is achieved, controlling the deviation of finished product porosity within a preset deviation range, and greatly improving the yield of high-quality functional fabrics.

[0035] (5) The method of this invention is not only applicable to the field of sports and outdoor activities, but can also be extended to multiple fields such as medical dressings and special protective clothing by adjusting the raw material composition and tissue parameters. By introducing functional fibers, more additional functions can be given to the fabric while maintaining the gradient density structure. This multi-dimensional and multi-level technical framework provides a solid structural foundation and technical support for the development of the next generation of smart textiles. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart of a knitted fabric weaving method with a gradient density structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the unidirectional moisture-wicking core principle framework based on the porosity gradient in the thickness direction according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the logical flow framework of the mapping between raw material characteristics and process parameters, as well as the online monitoring and closed-loop adjustment, according to an embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, but not all embodiments. Example

[0039] like Figure 1 As shown, this embodiment discloses a method for weaving knitted fabrics with a gradient density structure. Its core lies in directly constructing a stable physical density gradient along the fabric thickness direction through structured control during the weaving process. The specific execution process strictly follows these steps: In the method, step 1 involves the collaborative design of raw material combinations and multilayer structures. This step aims to lay the physical foundation for the formation of gradient density structures through the pre-configuration of material properties and geometric topology.

[0040] Specifically, in step 1, the surface layer material is selected from fine denier chemical fiber filaments, with the single filament fineness set within a preset range. The chemical fiber filaments specifically include polyester fibers or polyamide fibers. The close arrangement of high-count filaments forms a high-density surface layer structure, giving the fabric surface excellent strong support and quick-drying properties. At the microscopic level, the close packing of fine denier filaments can form extremely small microporous structures. These micropores, acting as capillary ends, can generate extremely strong suction force. Before weaving, the surface layer material undergoes cold plasma treatment with a treatment power set within a preset power range and a treatment time set within a preset duration to increase the surface roughness and hydrophilic group content of the fibers, further enhancing the surface layer's ability to diffuse and evaporate moisture. The surface layer material has an irregular cross-sectional shape; the microgrooves formed by the irregular cross-section generate additional capillary force, which, in conjunction with the gradient density structure, accelerates the release of moisture into the atmosphere.

[0041] In step 1, such as Figure 2 As shown, the inner layer material is made of coarse denier yarn or blended yarn, with its linear density set within a preset range. The blended yarn is made of a predetermined proportion of combed cotton fiber and modified polyester fiber, utilizing the hydrophilicity of natural fibers and the moisture-wicking properties of modified fibers to construct a loose inner layer structure with high moisture absorption capacity. Silver ion modified fibers with antibacterial function are added to the inner layer material, with the addition ratio set within a preset range. Through uniform distribution during the weaving process, the finished fabric achieves durable antibacterial and deodorizing properties while possessing a gradient density structure. The loops formed by the coarse denier yarn have a large internal volume, capable of holding a large amount of liquid sweat, and using its low capillary pressure to push moisture towards the middle layer.

[0042] In step 1, the middle layer material serves as the connecting link between the surface layer and the inner layer. Highly elastic monofilaments are selected, with their diameter set within a preset range. Specific weaving points tightly lock the surface layer and inner layer together, ensuring that the multi-layer structure does not experience interlayer displacement or peeling when subjected to external tensile forces. The interlacing point spacing of the middle layer connecting filaments is set within a preset range. By optimizing the arrangement of these interlacing points, the obstruction to the vertical moisture transfer path is minimized while ensuring interlayer bonding strength.

[0043] In step 1, the composite knitted structure is woven using a double-sided circular knitting machine. The outer layer uses a plain knit weave, while the inner layer uses a combination of tuck and weft insertion structures. By changing the distribution density of the tuck points, an asymmetrical pore distribution is formed inside the fabric, thereby generating a capillary pressure difference from the inside out. The composite knitted structure also incorporates a tuck suspension structure, which reduces the number of loops in specific areas to create tiny air layers. These air layers not only increase the fabric's warmth retention but also act as a buffer zone for moisture migration, regulating the residence time of moisture in the gradient density structure.

[0044] When constructing the initial physical model, the parameter configuration of each layer is determined by calculating the capillary pressure gradient along the thickness direction. The calculation of capillary pressure follows the formula:

[0045] in, The surface tension of the liquid, The contact angle of the fiber surface. This is the equivalent capillary pore size. It is achieved by configuring extremely small [pore sizes] on the surface layer. A larger value is configured in the inner layer to achieve pressure difference drive in the thickness direction.

[0046] In the method, step 2 configures the process parameters of the weaving equipment. This step, based on the physical model designed in step 1, transforms the abstract structural requirements into executable machine language.

[0047] Specifically, in step 2, the yarn feed rate is set according to a gradient decreasing principle. The yarn feed speed of the inner layer is set to a first preset yarn feed speed, the yarn feed speed of the middle layer is set to a second preset yarn feed speed, and the yarn feed speed of the surface layer is set to a third preset yarn feed speed. Precise control of the coil size is achieved through differentiated yarn feed speeds. This layered setting of the yarn feed rate ensures that the inner layer coils have sufficient slack space to form large air pores, while the surface layer coils are in a confined state to form dense small air pores.

[0048] In step 2, the weaving tension is controlled by an electronic weft feeder. The dynamic tension of the inner layer yarn is set to a first preset tension value, the tension of the middle layer connecting yarn is set to a second preset tension value, and the tension of the outer layer filament is set to a third preset tension value. This high-precision tension control prevents the breakage of fine denier filaments during high-speed weaving while ensuring that coarse denier yarns can form a stable geometric shape.

[0049] In step 2, the coil length of the looping system is achieved by adjusting the pressure needle depth. The inner layer coil length is set to a first preset length, and the outer layer coil length is set to a second preset length. This significant difference in coil length creates a clear density gradient along the fabric thickness direction.

[0050] In step 2, such as Figure 3 As shown, the mapping relationship between raw material properties and process parameters is realized through the establishment of a mathematical model. This model comprehensively considers the friction coefficient, elastic modulus, and bending stiffness of the yarn, and predicts the fabric density distribution under different parameter combinations through numerical simulation, with the prediction error controlled within a preset error range.

[0051] In the method, step 3 performs integrated weaving. This step transforms multiple layers of raw materials into finished fabric within the same process cycle through the coordinated movement of the knitting equipment.

[0052] Specifically, in step 3, the needle bed spacing of the knitting equipment is set to a preset spacing, and a multi-path yarn feeding method is adopted. Each yarn feeding system is equipped with an independent tension compensation device to ensure that the raw materials of the surface layer, middle layer, and inner layer can be precisely interwoven in the same loop-forming cycle during operation. After the knitting equipment is started, the control system drives the needle bed to knit synchronously according to the preset weave cycle. In each loop-forming process, the surface layer raw material first enters the loop-forming trajectory, followed by the middle layer connecting yarn and the inner layer raw material being fed in sequentially. Through this precise time difference and spatial displacement coordination, a multi-layer integrated fabric structure with a continuous interface is directly formed in the weaving process, thereby eliminating the possibility of interlayer separation in a physical sense.

[0053] In step 3, a fully automated fabric doffing device is used during the weaving process, which monitors the fabric roll diameter using an infrared sensor. When the diameter reaches a preset threshold, the system automatically performs fabric cutting and roll changing actions, achieving a repeatability accuracy within a preset range, significantly improving the automation level of the production line. Furthermore, the weaving equipment is equipped with an automatic fabric breakage and stop device. The sensor sensitivity is set to a preset response time. When any raw material breaks or experiences abnormal tension, the equipment immediately stops operating and issues an audible and visual alarm signal, ensuring that the continuity of the gradient density structure is not disrupted.

[0054] In the method described, step 4 involves dynamic monitoring and closed-loop adjustment. This step uses a real-time feedback mechanism to compensate for deviations during the weaving process, ensuring consistent product quality.

[0055] Specifically, in step 4, the online monitoring sensor is a piezoelectric tension sensor, and the sampling frequency is set to a preset sampling frequency. The sensor is deployed between the yarn feed inlet and the loop-forming area to collect yarn tension fluctuation data in real time. The sensor transmits the collected raw signal to the central processing unit through an analog-to-digital converter circuit. The central processing unit uses a digital filtering algorithm to remove high-frequency noise and employs a proportional-integral-derivative control algorithm to calculate the correction value for the yarn feed amount.

[0056] Corrected yarn feed speed Compared to the original set speed The relationship between them follows the formula below:

[0057] in, For real-time tension deviation, These are the proportional, integral, and derivative coefficients, respectively. By driving a servo motor to adjust the speed of the yarn feed disc, the adjustment accuracy reaches the preset value, thereby ensuring the uniformity of the gradient density structure throughout the entire roll of fabric.

[0058] In the method, step 5 involves post-processing and finished product inspection. This step, through physical curing and performance verification, completes the final product delivery.

[0059] Specifically, in step 5, the heat setting process is performed on a tenter frame. The setting temperature is set within a preset temperature range, and the processing time is set within a preset time period. Heat energy causes the chemical fibers to physically shrink, further solidifying the gradient density structure and improving the dimensional stability of the fabric. During the heat setting process, the fabric width and overfeed rate are strictly monitored to prevent excessive stretching that could damage the established pore gradient.

[0060] In step 5, the finished product testing process includes evaluating the fabric using a liquid moisture management tester. Testing indicators include wetting time, water absorption rate, maximum wetting radius, diffusion rate, and unidirectional moisture conduction index. The unidirectional moisture conduction index must meet a preset moisture conduction threshold, and the overall moisture management capability must reach a predetermined level standard. The porosity distribution of the gradient density structure exhibits a non-linear change in the thickness direction. The inner layer porosity is set within a first preset porosity range, the middle layer porosity within a second preset porosity range, and the surface layer porosity within a third preset porosity range. This structural arrangement from loose to dense generates a strong pressure driving force, prompting moisture to spontaneously migrate to the outer layer.

[0061] The method produces knitted fabrics with a total weight controlled within a preset weight range, a thickness controlled within a preset thickness range, and both longitudinal and transverse shrinkage rates less than or equal to preset shrinkage thresholds, meeting the requirements for high-performance sports fabrics.

[0062] Furthermore, the method for weaving knitted fabrics with a gradient density structure also includes temperature and humidity control of the weaving environment. The workshop temperature is maintained within a preset ambient temperature range, and the relative humidity is maintained within a preset ambient humidity range to reduce the impact of static electricity on the fine denier filament weaving process and ensure the smoothness of the fabric surface.

[0063] The mechanism by which the unidirectional moisture-wicking function is achieved is that liquid water in the inner layer's large-pore structure is drawn to the middle layer under capillary pressure, and then transferred from the middle layer to the surface layer's small-pore structure. Due to the high-density characteristics of the surface layer, moisture rapidly diffuses laterally, greatly increasing the evaporation area, thereby achieving the technical effect of moisture absorption and rapid drying.

[0064] Example 2 To further verify the applicability of the present invention under different functional requirements, Example 2, based on Example 1, optimizes and integrates the weaving process for specific ergonomic needs.

[0065] In Embodiment 2, the composite knitting structure designed in Step 1 was regionally adjusted. By adjusting the arrangement frequency of the weft yarns, specific functional areas were formed on the fabric surface, including a high-breathability area and a high-support area. The porosity of the high-breathability area was increased by a predetermined ratio compared to the conventional area to meet the heat dissipation needs of different parts of the human body. Specifically, during the weaving cycle, the entry and exit of the weft yarns were controlled by an electronic needle selection system. The weft density was reduced in the high-breathability area, while the frequency of the gathering points was increased in the high-support area.

[0066] In Embodiment 2, step 2 establishes a dynamic parameter library for switching functional areas. When the equipment operates to the high-breathability zone weaving instruction, the control system automatically switches to the fourth preset yarn feed speed and the fourth preset tension value to adapt to changes in local fabric density. This instantaneous switching of parameters is triggered by the central processing unit based on preset displacement encoder signals, ensuring a natural and flawless structural transition at the area transition.

[0067] In Embodiment 2, an online spraying system for functional auxiliaries is introduced into the integrated weaving process of step 3. Before the surface layer raw material is fed into the loop-forming area, a micro-spray device uniformly coats the filament surface with a preset proportion of hydrophilic modifier. This process is synchronized with the weaving action, which not only enhances the capillary suction power of the surface layer but also avoids the damage to the hydrophobicity of the inner layer caused by traditional padding processes.

[0068] In Embodiment 2, the monitoring scope of step 4 is extended to fabric surface smoothness. A high-resolution industrial camera captures real-time images of the fabric surface, and a convolutional neural network algorithm identifies possible coil distortions or uneven porosity. Once a deviation exceeds a preset threshold, the system immediately adjusts the needle depth of the corresponding yarn feeding path, achieving closed-loop correction in the spatial dimension.

[0069] In Embodiment 2, the heat setting process in step 5 employs a segmented temperature control mode. Different temperature gradients are set in the inlet, middle, and outlet sections of the tenter frame to accommodate the differences in thermal shrinkage due to varying fiber content in the functional areas. Finished product testing results show that the knitted fabric prepared using this method maintains excellent unidirectional moisture-wicking properties while increasing local air permeability by a predetermined percentage, significantly improving wearing comfort under extreme sports conditions.

[0070] Example 3 Example 3 focuses on further enhancing the durability and multi-dimensional protective performance of gradient density structures through raw material modification and microstructure fine-tuning.

[0071] In Example 3, the inner layer material selected in step 1 is a specially treated bamboo charcoal modified blended yarn. This yarn not only has good moisture absorption but also provides additional odor adsorption capacity through its porous microstructure. The outer layer material is a high-strength recycled polyester filament with a monofilament breaking strength set within a preset strength range. By increasing the interlacing tightness of the loops, the anti-pilling and anti-fuzzing properties of the fabric are improved, enabling it to meet the preset grade standard.

[0072] In embodiment 3, step 2 involves microscopic optimization of the coil geometry of the coiling system. By designing an asymmetrical pressure needle triangle curve, the coil is deflected at a predetermined angle during the coiling process. This deflection causes the opening direction of the inner coil to be more conducive to capturing sweat droplets on the skin surface, while the deflection of the outer coil helps moisture to diffuse rapidly in a specific direction.

[0073] In embodiment 3, step 3 introduces a multi-stage tension compensation mechanism. In addition to the primary tension control of the electronic weft feeder, an active tension adjusting roller is added at the needle bed inlet. This roller adjusts the yarn's running resistance in real time via an electromagnetic brake based on fluctuations in the spindle speed, controlling tension fluctuations within a preset, minimal range. This multi-stage control ensures that localized collapse of physical properties does not occur when producing high-grammage, high-density gradient fabrics.

[0074] In embodiment 3, the closed-loop control system in step 4 integrates an environmental compensation algorithm. The system acquires data from the workshop temperature and humidity sensors in real time and automatically fine-tunes the yarn feed correction coefficient based on environmental changes. For example, when increased ambient humidity leads to increased fiber friction, the algorithm automatically increases the yarn feed compensation to offset the coil shrinkage effect caused by increased tension.

[0075] In Embodiment 3, the detection step in step 5 includes an accelerated simulation test of wash resistance. After the fabric undergoes a preset number of standard washing cycles, a liquid moisture management test is performed again. The results show that, since the gradient density structure is directly constructed during the weaving process, neither the interlayer strength retention rate nor the unidirectional moisture conductivity index shows a significant decrease, verifying the significant advantage of this invention in terms of structural stability.

[0076] In addition, such as Figure 3 As shown, this embodiment also explores in detail the performance of the mathematical model mapping the relationship between raw material properties and process parameters under complex structures. By introducing the finite element analysis method, the deformation law of the gradient pore structure under different tensile stresses was simulated. The simulation results were fed back into the parameter setting in step 2 to optimize the selection of the elastic modulus of the middle layer connecting yarn, ensuring that the moisture conduction channels of the fabric remain unobstructed even if it undergoes significant deformation during use.

[0077] In the specific implementation of the method, the ratio of the fine denier of the surface layer material to the coarse denier of the inner layer material is defined as the gradient factor. By adjusting this gradient factor, the migration rate of liquid moisture in the thickness direction can be precisely controlled. Experimental data show that when the gradient factor is within the preset optimization range, the unidirectional moisture-wicking index of the fabric reaches its maximum value, and the drying rate of the surface layer is increased by a predetermined proportion compared to traditional fabrics.

[0078] During the weaving process, in response to the problem of static electricity easily generated in fine denier chemical fiber filaments, in addition to controlling the ambient temperature and humidity, an active ion neutralization device is also arranged on the yarn feeding path. The ion flow released by this device can quickly neutralize the charge on the yarn surface, preventing the fibers from scattering due to electrostatic repulsion, thereby ensuring the regularity of the high-density structure of the surface layer.

[0079] For the weft insertion structure in composite knitted fabrics, this embodiment employs a special weft insertion device that can embed functional yarns into the surface and inner layers along a preset trajectory without altering the main fabric cycle. This technology not only enhances the dimensional stability of the fabric but also finely adjusts the effective porosity of the middle layer through the physical placement of the weft insertion yarns, further optimizing the capillary pressure transmission chain.

[0080] For the heat-set finished product, this embodiment also conducted a series of performance evaluations. In addition to the core heat and moisture management indicators, it also included an objective evaluation of the fabric's hand feel. The results of the fabric style tester showed that, due to the use of coarse denier blended yarn in the inner layer and the maintenance of a loose structure, the fabric exhibited excellent compression resilience and softness. This structural design not only achieved a functional breakthrough but also ensured a skin-friendly feel when worn close to the skin.

[0081] In summary, this invention, through a systematic innovation across the entire process from raw material selection, fabric design, parameter control to online monitoring, successfully constructs a high-performance, highly stable gradient density structure directly during the weaving stage. This method not only simplifies the production process and reduces environmental impact, but also provides a mature technical solution for developing novel knitted fabrics with superior heat and moisture management capabilities.

[0082] In actual production, this method has demonstrated extremely high flexibility. By changing the combination of raw materials, it is possible to quickly switch from sports fabric production mode to medical protective fabric production mode. For example, in the application of medical dressings, the inner layer can be replaced with viscose fiber with high absorbency, while the outer layer retains dense polyester filaments to prevent the invasion of external bacteria. At the same time, the gradient density structure is used to quickly drain wound exudate, keeping the wound surface moderately moist and clean.

[0083] In terms of automation control, the closed-loop control system adopted in this invention has good scalability. Through reserved data interfaces, it can be deeply integrated with the factory's ERP and MES systems. All process parameters, tension curves, and environmental data during the weaving process are recorded in real time and uploaded to a cloud server. Using big data analytics, the mapping model between raw material characteristics and process parameters can be further optimized, achieving continuous evolution of product quality.

[0084] For the maintenance of weaving equipment, this embodiment also establishes a data-driven preventive maintenance plan. By analyzing the long-term data trends collected by tension sensors, the wear status of key loop-forming components such as knitting needles and sinkers can be predicted. When the data characteristics match the preset wear model, the system will automatically issue a maintenance reminder, thereby avoiding fabric defects caused by component aging and ensuring the precision of the gradient density structure.

[0085] In terms of environmental performance, since this invention relies entirely on physical structure to achieve unidirectional moisture wicking, the use of chemical hydrophilic and hydrophobic agents is significantly reduced. This not only reduces the burden of wastewater treatment during the production process but also improves the product's biosafety and reduces the potential irritation of chemicals to the wearer's skin. The recycling of the finished fabric is also more convenient, as it is mainly composed of physical weave and does not contain complex coating materials, aligning with the development concept of a circular economy.

[0086] In this method, the thickness of the air layer in the fabric can be changed by adjusting the length of the middle layer connecting yarn to meet the fabric requirements of different seasons. In winter sports fabrics, appropriately increasing the length of the middle layer can create a thicker static air layer, thereby significantly improving the fabric's warmth coefficient while maintaining its unidirectional moisture-wicking function. This fine-tuning in the thickness direction is achieved entirely through the needle depth adjustment in step 2, without the need to change any equipment parts.

[0087] Statistical analysis of a large number of experimental samples revealed that the porosity distribution of the gradient density structure described in this invention along the thickness direction... It satisfies the following nonlinear distribution law:

[0088] in, The depth from the inner layer, The initial porosity of the inner layer, This represents the gradient attenuation coefficient. By precisely controlling the yarn feed and tension in step 2, the gradient attenuation coefficient can be reduced. The value remains stable within the preset optimal range, thereby ensuring the high efficiency of water migration.

[0089] During the weaving process, to prevent damage to the fine denier filaments in the surface layer due to stress concentration at the moment of loop formation, this embodiment employs a gentle curve in the geometric design of the loop formation triangle. This design extends the loop formation time and reduces peak tension, allowing the raw material to smoothly complete the geometric transformation from yarn to loop. This extreme optimization of the microscopic motion trajectory is one of the key technical details ensuring the perfect presentation of the gradient density structure.

[0090] In step 5 of the method, the surface friction characteristics of the fabric are also detected. Because the surface layer uses high-density fine denier filaments, its surface friction coefficient is controlled within a preset low range. This not only improves the fabric's abrasion resistance but also reduces frictional resistance between the clothing and air, and between garments themselves, during movement, thus providing a certain degree of athletic assistance.

[0091] In the described embodiment, through the synergistic design of the raw materials and the fabric structure, the porosity gradient of the fabric remains relatively stable when subjected to multi-directional stretching. This is because the middle layer connecting yarn uses monofilaments with a specific elastic modulus, which can play a supporting and limiting role during stretching, preventing the collapse of the interlayer structure. This mechanical stability is crucial for functional sportswear, ensuring that the moisture-wicking properties of the fabric do not fail instantaneously under the athlete's wide range of movements.

[0092] During the weaving process, in addition to the ion neutralization device, conductive ceramic yarn guides are added to the yarn path to address potential electrostatic interference. These components effectively discharge and ground the static charge generated during yarn movement, further ensuring the orderly arrangement of fine denier filaments.

[0093] For the unidirectional moisture wicking index testing of finished fabrics, this embodiment employs a multi-point sampling evaluation method. A predetermined number of sample blocks are randomly selected from different parts of the entire roll of fabric and tested separately. Consistency analysis of the test results shows that, due to the use of the closed-loop adjustment system in step 4, the coefficients of variation of each performance index are controlled within a predetermined extremely low range, demonstrating the reliability of this invention in large-scale industrial production.

[0094] Finally, the method described in this invention has significant advantages in production efficiency. By eliminating multiple drying and chemical reaction steps in post-processing, the production cycle for a single batch of products is shortened by a predetermined percentage. This not only improves the company's market responsiveness but also significantly reduces energy consumption per unit product. This weaving method, which balances high performance, high efficiency, and high environmental friendliness, represents the development direction of modern functional textile technology.

[0095] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for weaving a knitted fabric with a gradient density structure, characterized in that, Includes the following steps: Step 1: Collaboratively design the raw material combination and multi-layer structure. Based on the preset moisture absorption and perspiration performance index, select the components of the surface material, middle material and inner material respectively, and design a composite knitting structure including yarn filling structure and weft filling structure. Through the pre-configuration of the surface material, middle material and inner material in geometric topology, construct a preliminary physical model with a density gradient in the thickness direction. Step 2: Configure the process parameters of the weaving equipment. Based on the preliminary physical model, set the yarn feeding speed of the yarn feeding device, the dynamic tension of the weaving mechanism, and the loop length of the loop forming system in segments. By establishing the mapping relationship between the raw material characteristics of the raw material combination and the process parameters, the structural requirements are transformed into machine execution instructions. Step 3: Perform integrated weaving and forming, start the knitting equipment, control the surface material, middle material and inner material to be knitted synchronously according to the preset structure cycle, and use the multi-way yarn feeding system to complete the interweaving in the same loop cycle, directly forming a multi-layer integrated fabric structure with continuous interface in the weaving process. Step 4, Dynamic monitoring and closed-loop adjustment: Online monitoring sensors are used to collect yarn tension fluctuation data in real time during the weaving process. The collected tension signals are transmitted to the central processing unit, and the yarn feed amount is corrected in real time through feedback control loop to compensate for the impact of raw material differences and maintain the uniformity of gradient density structure. Step 5, post-processing and finished product inspection: The woven knitted fabric is subjected to heat setting treatment. The gradient density structure is solidified by inducing physical shrinkage of the fibers through heat energy. The porosity distribution and unidirectional moisture conduction index in the thickness direction are detected to verify the directional conduction efficiency of liquid moisture in the gradient density structure.

2. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 1, the surface layer material is selected from fine denier chemical fiber filaments, including polyester fibers or polyamide fibers. A high-density surface layer structure is formed by the close arrangement of high-count filaments. The surface layer material is treated with cold plasma before weaving to increase the surface roughness and hydrophilic group content of the fibers. The cross-sectional shape of the surface layer material is an irregular cross-section, and capillary force is generated through the micro-grooves formed by the irregular cross-section. The inner layer material is selected from coarse denier yarn or blended yarn. The blended yarn is made by blending combed cotton fibers and modified polyester fibers in a predetermined proportion. The inner layer material contains silver ion modified fibers, and the inner cavity volume formed by the coarse denier yarn can accommodate liquid sweat. The middle layer material is selected from highly elastic monofilaments, which serve as the connecting link between the surface layer material and the inner layer material.

3. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 1, the composite knitting structure is woven using a double-sided circular knitting machine. The surface layer material uses a plain knit weft weave, and the inner layer material uses a combination of tuck weave and weft-insertion weave. By changing the distribution density of the tuck points, an asymmetrical pore distribution is formed inside the fabric, generating a capillary pressure difference from the inside out. The composite knitting structure also introduces a tuck suspension weave, which reduces the number of loops in specific areas to form an air layer with heat retention and moisture migration buffering properties. When constructing the preliminary physical model, the parameter configuration of each layer is determined by calculating the capillary pressure gradient in the thickness direction. A preset small equivalent capillary pore size is configured in the surface layer material, and a preset large equivalent capillary pore size is configured in the inner layer material to achieve pressure difference driving in the thickness direction.

4. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 2, the yarn feeding rate is set according to a gradient decreasing principle. The yarn feeding speed of the inner layer material is set to a first preset yarn feeding speed, the yarn feeding speed of the middle layer material is set to a second preset yarn feeding speed, and the yarn feeding speed of the outer layer material is set to a third preset yarn feeding speed. By controlling the coil size through differentiated yarn feeding speeds, it is ensured that the coil formed by the inner layer material has a relaxed space to form large air holes, while the coil formed by the outer layer material is in a restricted state to form dense small air holes. The knitting tension is controlled by an electronic weft feeder. The dynamic tension of the inner layer material, the middle layer material, and the outer layer material is set to a first preset tension value, a second preset tension value, and a third preset tension value, respectively. The coil length of the looping system is achieved by adjusting the pressure needle depth. The coil lengths of the inner layer material and the outer layer material are set to a first preset length and a second preset length, respectively.

5. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 2, the mapping relationship between the raw material characteristics and process parameters is realized by establishing a mathematical model. The mathematical model comprehensively considers the friction coefficient, elastic modulus, and bending stiffness of the yarn, and predicts the fabric density distribution under different parameter combinations through numerical simulation, and controls the prediction error within a preset error range. For specific functional requirements, the mathematical model is also used to optimize the selection of the elastic modulus of the middle layer raw material, so as to ensure that when the fabric is subjected to multi-directional tension, the stability of the porosity gradient is maintained by the support and limiting effect of the middle layer raw material, preventing the collapse of the interlayer structure and ensuring the smooth flow of moisture conduction channels.

6. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 3, the needle bed spacing of the knitting equipment is set to a preset needle spacing, and a multi-path yarn feeding method is adopted. Each yarn feeding system is equipped with an independent tension compensation device to ensure that the surface material, the middle material, and the inner material are interwoven in the same looping cycle. In each looping process, the surface material first enters the looping trajectory, followed by the middle material and the inner material being fed in sequentially. Through the combination of time difference and spatial displacement, a multi-layer integrated fabric structure with a continuous interface is formed. A fully automatic fabric doffing device is used during the weaving process. The diameter of the fabric roll is monitored by an infrared sensor. When the diameter reaches a preset diameter threshold, the fabric cutting and roll changing actions are automatically performed. The knitting equipment is also equipped with an automatic yarn breakage and self-stop device. When any material in any path breaks or has abnormal tension, the operation stops and an alarm signal is issued.

7. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 4, the online monitoring sensor is a piezoelectric tension sensor deployed between the yarn feed inlet and the coiling area. The sensor transmits the collected tension signal to the central processing unit through an analog-to-digital converter circuit. The central processing unit uses a digital filtering algorithm to remove high-frequency noise from the signal and uses a proportional-integral-derivative control algorithm to calculate the correction value of the yarn feed amount. The correction value is determined based on the real-time tension deviation, proportional coefficient, integral coefficient, and derivative coefficient. The central processing unit drives a servo motor to adjust the rotation speed of the yarn feed disc, adjusting the accuracy to a preset accuracy value, thereby compensating for coil size deviations caused by raw material differences or tension fluctuations and maintaining the uniformity of the gradient density structure in the entire roll of fabric.

8. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, In step 5, the heat setting treatment is carried out on a tenter frame, with the setting temperature set within a preset temperature range and the processing time within a preset time period. The heat energy causes the chemical fibers to physically shrink in order to solidify the gradient density structure and improve the dimensional stability of the fabric. During the heat setting process, the fabric width and overfeed rate are monitored in real time to prevent excessive stretching from damaging the established pore gradient. The heat setting process also adopts a segmented temperature control mode, setting different temperature gradients in different sections of the tenter frame to adapt to the thermal shrinkage differences of different fiber contents in functional areas, ensuring the smoothness and structural consistency of the finished fabric.

9. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, The finished product testing process includes using a liquid moisture management tester to evaluate immersion time, water absorption rate, maximum immersion radius, diffusion rate, and unidirectional moisture conduction index, which must meet a preset moisture conduction threshold. The porosity distribution of the gradient density structure in the thickness direction exhibits a non-linear change. The porosities of the inner layer material, the middle layer material, and the outer layer material are respectively set within a first preset porosity range, a second preset porosity range, and a third preset porosity range. The pressure driving force generated by the structural arrangement from loose to dense promotes the spontaneous migration of moisture to the outer layer. The finished product testing also includes evaluating the surface friction characteristics of the fabric. By controlling the arrangement density of the outer layer material, the surface friction coefficient is controlled within a preset low value range to improve the fabric's abrasion resistance.

10. The method for weaving a knitted fabric with a gradient density structure according to claim 1, characterized in that, The method also includes temperature and humidity control of the weaving environment. The workshop temperature is maintained within a preset ambient temperature range, and the relative humidity is maintained within a preset ambient humidity range. An active ion neutralization device and a conductive ceramic yarn guide are arranged on the yarn feeding path to suppress the influence of static electricity on the fine denier filament weaving process. By adjusting the arrangement frequency of the weft yarns in the weft-inserting structure, high-permeability zones and high-support zones with different porosities are formed on the fabric surface. The porosity of the high-permeability zone is increased by a predetermined proportion compared with the conventional zone. The total weight of the knitted fabric produced by the method is controlled within a preset weight range, the thickness is controlled within a preset thickness range, and both the longitudinal shrinkage rate and the transverse shrinkage rate are less than or equal to a preset shrinkage rate threshold.

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