Sudoku three-dimensional fabric forming process

Abstract

The invention relates to a Sudoku three-dimensional fabric forming process which comprises the following steps: constructing a three-dimensional skeleton with at least 3 * 3 array cavities by adopting first warp yarns, second warp yarns and weft yarns of a skin-core structure; a first type of orthogonal interaction locking structure is adopted at a central node, and a second type of surrounding bundling structure is adopted at peripheral nodes, so that the overall stability is enhanced; then, functional materials are injected into the cavities, the first warp skin layer is melted or dissolved in a heat or solvent mode and then solidified, and therefore the functional materials are sealed in the cavities of all the units; and finally binding knots by using weft yarns and applying hot pressing for reinforcement. The process can realize differentiated design of the cavity structure and stable packaging of the functional material, and is suitable for preparing the composite material preform with thermal management, sensing or bearing functions.

Description

Technical Field

[0001] This application relates to the field of textile manufacturing technology, and in particular to a three-dimensional fabric forming process for a nine-grid pattern. Background Technology

[0002] With advancements in technology and increasing demand for high-performance materials, the research and development of functional textiles has garnered growing attention. Traditional two-dimensional fabrics have limitations in structure and function, making it difficult to meet the needs of certain specialized applications, such as smart textiles requiring integrated sensing, heating, cooling, energy storage, or shock absorption functions. Three-dimensional fabrics, especially those with internal cavity structures, offer new avenues for the encapsulation and integration of functional materials.

[0003] Currently, the main manufacturing methods for three-dimensional fabrics include multi-layer weaving, three-dimensional knitting, and stitching. However, existing three-dimensional fabric manufacturing technologies struggle to precisely form internal cavities with specific geometric arrangements (such as a nine-square grid), and the control precision over the size and shape of these cavities is not high. Furthermore, the yarn nodes inside the three-dimensional fabric are critical stress-bearing components; if the node connection strength is insufficient, it can easily lead to a loose fabric structure, affecting its overall performance and the encapsulation stability of functional materials.

[0004] Therefore, we propose a nine-grid three-dimensional fabric forming process. Summary of the Invention

[0005] The purpose of this application is to provide a nine-grid three-dimensional fabric molding process, which aims to solve the problems of insufficient functional material encapsulation, mechanical properties and functionality balance, production efficiency and cost, and insufficient node connection strength in the existing technology.

[0006] To achieve the above objectives, this application provides a nine-grid three-dimensional fabric molding process, comprising the following steps:

[0007] S1. Provide a first warp yarn, a second warp yarn, and a weft yarn, wherein the first warp yarn and the second warp yarn are both core-sheath structures, and the melting point or dissolution temperature of the sheath layer is 20–80°C lower than that of the core layer;

[0008] S2. The first warp yarn is laid out along the thickness direction of the fabric, the second warp yarn is laid out along the length direction of the fabric, and the weft yarn is laid out along the width direction of the fabric to form a three-dimensional skeleton prototype with no less than 3 layers.

[0009] S3. Within the three-dimensional skeleton prototype, a three-dimensional orthogonal or angular interlocking structure is used for weaving. The first warp yarn in the Z direction binds the weft yarn in the X direction and the second warp yarn in the Y direction to form a nine-square grid structure with at least a 3×3 array cavity.

[0010] S4. At the cavity node located at the geometric center, the center yarn of the first warp yarn is interlaced, folded back, and wrapped around the center yarn of the second warp yarn to form a first type of positive interlocking node; at the eight peripheral cavity nodes surrounding the central node, the upper and lower yarns of the first warp yarn are wrapped around the left and right yarns of the second warp yarn at non-orthogonal angles to form a second type of surrounding binding node;

[0011] S5. After the cavity is formed and before the node structure is completely tightened and fixed, inject functional material into the cavity;

[0012] S6. The skin of the first warp yarn is melted by heating or dissolved by solvent, and then re-cured or solidified to enclose the functional material inside the cavity of each unit.

[0013] S7. Use the weft yarn to tie each node and apply a heat pressure of 0.2–0.8 MPa to the fabric to reinforce it.

[0014] Preferably, the melting of the first warp yarn skin layer is induced by hot pressing, and the solidification is achieved by blowing a cold airflow at 5–15°C for 0.5–2 seconds; the dissolution of the first warp yarn skin layer is achieved by spraying 5–10wt% CaCl2 or NaCl aqueous solution at 0.05–0.2 g / cm² for solidification.

[0015] Preferably, the first warp yarn has a core-sheath volume ratio of 30 / 70–50 / 50 and a sheath melting point or dissolution temperature ≤180℃; the second warp yarn has a core-sheath volume ratio of 20 / 80–40 / 60 and a sheath melting point or dissolution temperature 10–30℃ higher than that of the first warp yarn.

[0016] Preferably, the first warp yarn, the second warp yarn, and the weft yarn are all made of monofilament, multifilament, air-textured yarn, or core-spun yarn, with a yarn density of 2–20 tex.

[0017] Preferably, the breaking strength of the first warp yarn, the second warp yarn, and the weft yarn is not less than 10 cN / tex, and the initial modulus is not less than 20 GPa.

[0018] Preferably, the volume of the functional material injected into the central cavity is 1.5–2.0 times the volume injected into the outer cavity, and the viscosity of the functional material at a shear rate of 10 s⁻¹ is 50–500 mPa·s.

[0019] Preferably, the dimensions of the central cavity in the X, Y, and Z directions are 1.1–1.4 times the dimensions of the corresponding directions of the peripheral cavity.

[0020] Preferably, in step S7, the applied temperature of the thermal pressure is 50–120°C, and the holding time is 30–180 seconds.

[0021] Preferably, in step S6, the rate at which the skin melts or dissolves and then solidifies or solidifies is not less than 5°C / s.

[0022] Preferably, in step S5, the injected functional material is a liquid, a gel, or a phase change material microcapsule with a phase change temperature ≤100°C.

[0023] Preferably, when the functional material is a phase change material microcapsule, its particle size range is 1-50 μm and its phase change enthalpy is not less than 150 J / g.

[0024] Preferably, in step S4, the non-orthogonal angle is 30°-60°.

[0025] The beneficial effects of the technical solution of this invention are as follows:

[0026] Through three-dimensional orthogonal or angular interlocking weaving, combined with the binding effect of Z-direction warp yarns, a nine-grid structure with a 3×3 array cavity can be precisely formed, providing an ideal carrier for the orderly filling of functional materials.

[0027] By combining central positive interlocking nodes and peripheral surrounding binding nodes, the connection strength and stability of the yarn nodes inside the fabric are significantly enhanced, effectively preventing deformation of the cavity structure during the injection of functional materials and subsequent processing.

[0028] Functional materials are injected after the cavity is formed and before the nodes are tightened and fixed. By utilizing the melting or dissolving and then solidifying / coagulating characteristics of the first warp core structure, the functional materials are stably sealed inside each unit cavity, avoiding leakage and uneven distribution.

[0029] Precise control of parameters such as the melting point / solution temperature difference, core-sheath volume ratio, yarn mechanical properties, and hot pressing, cold air curing / solvent coagulation of core-sheath structure yarns ensures the smooth progress of the fabric forming process and the excellent performance of the final product.

[0030] By controlling the volume ratio of functional materials injected into the central cavity and the peripheral cavity, as well as the cavity size ratio after molding, the gradient distribution of functional materials or the integration of differentiated functions within the fabric can be achieved.

[0031] The binding effect of the weft yarns on the nodes and the overall hot-pressing reinforcement of the fabric further enhance the overall strength, modulus and structural stability of the fabric, enabling it to withstand more complex stress environments. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of the nine-grid three-dimensional fabric forming process in one embodiment of this application;

[0033] Figure 2This is a schematic diagram of a three-dimensional skeleton prototype according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a nine-grid structure cavity according to an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of a first type of positive interactive lock node according to an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of a second type of surrounding bundle node according to an embodiment of the present invention.

[0037] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0039] Furthermore, descriptions using terms such as "first" and "second" in this application are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one feature. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed in this application.

[0040] With advancements in technology and increasing demand for high-performance materials, the research and development of functional textiles has garnered growing attention. Traditional two-dimensional fabrics have limitations in structure and function, making it difficult to meet the needs of certain specialized applications, such as smart textiles requiring integrated sensing, heating, cooling, energy storage, or shock absorption functions. Three-dimensional fabrics, especially those with internal cavity structures, offer new avenues for the encapsulation and integration of functional materials.

[0041] Currently, the main manufacturing methods for three-dimensional fabrics include multi-layer weaving, three-dimensional knitting, and stitching. However, existing three-dimensional fabric manufacturing technologies struggle to precisely form internal cavities with specific geometric arrangements (such as a nine-square grid), and the control precision over the size and shape of these cavities is not high. Furthermore, the yarn nodes inside the three-dimensional fabric are critical stress-bearing components; if the node connection strength is insufficient, it can easily lead to a loose fabric structure, affecting its overall performance and the encapsulation stability of functional materials.

[0042] See Figure 1 This invention proposes a nine-grid three-dimensional fabric forming process, which includes the following main steps:

[0043] S1. Provide a first warp yarn, a second warp yarn, and a weft yarn, wherein the first warp yarn and the second warp yarn are both core-sheath structures, and the melting point or dissolution temperature of the sheath layer is 20–80°C lower than that of the core layer.

[0044] Specifically, the yarns used in step S1 include a first warp yarn (Z-direction yarn), a second warp yarn (Y-direction yarn), and a weft yarn (X-direction yarn).

[0045] Both the first and second warp yarns employ a core-sheath structure. This core-sheath structure consists of an outer sheath layer and an inner core layer. For example, the sheath layer can be low-melting-point polyester, polyethylene, or soluble polyvinyl alcohol (PVA), while the core layer can be high-melting-point polyester, polypropylene, or high-performance fibers such as carbon fiber or glass fiber.

[0046] In one embodiment, the melting point or dissolution temperature of the skin layer is lower than that of the core layer, and the temperature difference is controlled between 20 and 80°C. This design allows the skin layer to fix the internal structure of the fabric and encapsulate functional materials through subsequent heating and melting or solvent dissolution without affecting the core layer's structure and mechanical properties.

[0047] The core-sheath volume ratio of the first warp yarn is 30 / 70–50 / 50, and the melting point or dissolution temperature of the sheath layer is ≤180℃. The core-sheath volume ratio of the second warp yarn is 20 / 80–40 / 60, and the melting point or dissolution temperature of the sheath layer is 10–30℃ higher than that of the first warp yarn. This differentiated design is intended to allow the sheath layer of the first warp yarn in the Z-direction (thickness direction) to melt / dissolve preferentially during reinforcement. This ensures that the functional material is sealed and the basic structure is shaped while the longitudinal structure of the second warp yarn remains relatively intact, thus preventing the overall structure from collapsing due to simultaneous softening of the yarns.

[0048] In a preferred embodiment, the first warp yarn, the second warp yarn, and the weft yarn can all be made of monofilament, multifilament, air-textured yarn, or core-spun yarn, with a yarn density of 2–20 tex, a breaking strength of not less than 10 cN / tex, and an initial modulus of not less than 20 GPa. The selection of these yarn types and mechanical property parameters is crucial to ensuring that the constructed three-dimensional skeleton prototype has sufficient basic strength and stiffness to withstand the stresses of subsequent weaving, injection, and reinforcement processes.

[0049] S2. The first warp yarn is laid along the thickness direction of the fabric, the second warp yarn is laid along the length direction of the fabric, and the weft yarn is laid along the width direction of the fabric to form a three-dimensional skeleton prototype with no less than 3 layers.

[0050] Reference Figure 2 During the weaving process, the first warp yarn (Z-direction yarn) is mainly responsible for connecting the upper and lower layers of the fabric, forming support in the thickness direction; the second warp yarn (Y-direction yarn) extends along the length direction of the fabric; and the weft yarn (X-direction yarn) extends along the width direction of the fabric. Through multi-layer weaving technology, a three-dimensional skeleton with no fewer than three layers is constructed. This three-dimensional interwoven skeleton is the basis for forming the complex internal cavity structure and also provides a support network for the transmission of loads in all directions.

[0051] S3. Within the three-dimensional skeleton prototype, a three-dimensional orthogonal or angular interlocking structure is used for weaving to form a nine-grid structure with at least a 3×3 array cavity.

[0052] Specifically, based on the basic three-dimensional skeleton structure, three-dimensional or corner-locking weaving techniques are employed. Three-dimensional orthogonal weaving refers to the yarns interlacing in three mutually perpendicular directions to form a regular grid-like structure. Corner-locking weaving, on the other hand, builds upon orthogonal weaving by interlocking additional yarns at the corners, further enhancing the structure's integrity and resistance to delamination. The first warp yarn in the Z-direction precisely binds the weft yarn in the X-direction and the second warp yarn in the Y-direction together, thus forming a series of regular, isolated cavities within the fabric. (Refer to...) Figure 3 These cavities are arranged in a 4×5 array. This structural design not only endows the fabric with lightweight and high strength, but its regular cavities also provide physical space for the precise partitioning and loading of functional materials and subsequent gradient functional design.

[0053] S4. Form a first type of positive interactive lock node and a second type of surrounding bundle node at the node.

[0054] Reference Figure 4In one embodiment, at the geometric center cavity node of the nine-grid structure, the center yarns of the first warp and the center yarns of the second warp undergo complex interweaving, folding, and winding to form a first type of positive interlocking node. This interlocking method firmly binds the yarns from the X, Y, and Z directions at a single point, providing extremely high node strength and torsional resistance, ensuring the absolute stability of the central region as the structural core.

[0055] Reference Figure 5 At the eight peripheral cavity nodes surrounding the central node, the upper and lower yarns of the first warp yarns wrap around the left and right yarns of the second warp yarns at non-orthogonal angles of 30°-60°, forming a second type of surrounding binding node. This non-orthogonal wrapping method provides additional friction and binding force, effectively dispersing external stress and enhancing the node's resistance to tensile and shear forces. At the same time, compared to orthogonal interlocking, it retains a certain structural deformation capacity, helping to absorb impact energy. The differentiated design of the two types of nodes balances the "rigidity" (central stability) and "toughness" (peripheral cushioning) of the overall fabric structure.

[0056] S5. Inject functional material into the cavity.

[0057] Before the nine-grid structure is fully woven but the node structure has not been completely tightened and fixed through skin changes, functional materials are injected into the cavities of each unit through precision injection and other methods.

[0058] In one embodiment, the volume of functional material injected into the central cavity is 1.5–2.0 times the volume injected into the peripheral cavities, and the viscosity of the functional material at a shear rate of 10 s⁻¹ is 50–500 mPa·s. This volumetric gradient injection strategy, combined with the reinforcing nodes at the center of the nine-grid structure, allows the fabric to exhibit a "core-periphery" gradient functional effect with either a prominent center or enhanced performance in application. The appropriate viscosity range ensures that the functional material can smoothly fill the cavities without leaking or crossing into other cavities due to excessive fluidity before the subsequent curing step.

[0059] In one embodiment, the injected functional material can be a liquid, gel, or phase change material microcapsule. For example, injected phase change microcapsules can be used to manufacture smart temperature-regulating textiles, and injected magnetorheological fluids can be used to manufacture damping materials with variable damping. When phase change material microcapsules are selected as the functional material, their particle size range is 1-50 μm, and their phase change enthalpy is not less than 150 J / g, to ensure their efficient energy storage capacity and encapsulation stability in the fabric cavity.

[0060] S6. The functional material is sealed inside the cavity by heating and melting the first warp yarn skin layer or dissolving it with a solvent.

[0061] S7. Use weft yarns to bind the nodes and apply thermal pressure for overall reinforcement. Specifically, after the functional material is encapsulated, use weft yarns to additionally bind each node. This operation can further tighten the yarns, lock the node structure, and compensate for any slight loosening of the warp and weft yarn interlacing state that may be caused by the melting / dissolving of the skin.

[0062] Subsequently, a thermal pressure of 0.2–0.8 MPa and a temperature of 50–120°C is applied to the entire fabric and held for 30–180 seconds.

[0063] Furthermore, the hot pressing process in step S7 has multiple functions: First, it enables the first warp yarn skin layer (and possibly part of the second warp yarn skin layer) to melt and fuse further, making the bond between yarns and between layers stronger; Second, the pressure makes the fabric structure more compact, reduces porosity, and improves overall rigidity and strength; Third, the heat helps the residual solvent evaporate or promotes chemical reactions, making the encapsulation more thorough.

[0064] In one embodiment, if the sheath of the first warp yarn is a thermoplastic material (such as a low-melting-point polyester), the sheath of the first warp yarn is selectively melted by heating the entire fabric. The molten polymer flows and fills the microscopic gaps in the yarn interlacing points and cavity walls, forming a dense encapsulation layer that completely seals the functional material within its unit cavity.

[0065] In one embodiment, if the skin is a water-soluble material (such as PVA), it is dissolved by spraying a salt solution of a specific concentration (such as a 5–10 wt% CaCl2 solution). The dissolved skin forms a viscous solution, which re-solidifies after subsequent drying or a cross-linking reaction with the salt, thereby achieving the encapsulation purpose.

[0066] To achieve optimal encapsulation speed and results, in one embodiment, rapid re-curing is performed after melting by blowing with a cool airflow at 5–15°C for 0.5–2 seconds; or by spraying a coagulating liquid at 0.05–0.2 g / cm². The entire curing or solidification process should be carried out at a rate of no less than 5°C / s. Rapid curing effectively prevents the migration and leakage of functional materials before encapsulation, ensuring the functional independence of each cavity.

[0067] In one embodiment, after being formed by the above process, the central cavity will be slightly larger than the outer cavity in the X, Y, and Z directions, with a size ratio of 1.1–1.4 times.

[0068] Through innovative core-sheath structure yarn design, precise nine-grid weaving and differentiated node construction technology, and a "first-inject, then-encapsulate" process sequence, liquid or granular functional materials have been successfully and stably encapsulated within a three-dimensional textile structure. This surpasses traditional filling or coating finishing methods.

[0069] The functional fabrics prepared by this process have the following significant advantages:

[0070] Functional materials are precisely positioned and have long-lasting performance: The functional materials are firmly encapsulated in independent cavities, making them less prone to leakage, migration, or deactivation.

[0071] Excellent structural mechanical properties: The unique positive interlocking and wrap-around binding node design endows the fabric with extremely high node strength and overall structural stability.

[0072] Achieving functional gradient: By controlling the amount of functional material injected into different cavities and the final cavity size, a gradient distribution of functions (such as strong cooling in the center and weak buffering on the periphery) can be achieved within a single fabric to meet the needs of complex application scenarios.

[0073] Comparative Example 1

[0074] Ordinary single-component polyester yarn was used to replace the core-sheath structure yarn. Specifically, the first and second warp yarns were replaced with ordinary high-strength polyester multifilament yarn (without core-sheath structure) with a melting point of 260°C, while the weft yarns remained unchanged. After weaving, the same phase change microcapsule slurry (particle size 20μm, phase change enthalpy 180J / g) as in Example 1 was injected into the nine-grid cavity. Subsequently, the entire fabric was heated to 180°C and subjected to a pressure of 0.5MPa for 120 seconds.

[0075] Test Project Embodiment 1 of the present invention Comparative Example 1 Performance changes Z-axis peel strength (N / cm) 35.8 12.5 -65.2% Functional material filling rate (%) 95.2 38.7 -59.3% Node slip ratio (%) 2.1 18.6 +786% 30-day material leakage rate (%) 1.2 38.4 +3100%

[0076] Table 1

[0077] As shown in Table 1, due to the lack of a low-melting-point sheath in the yarn, the yarn as a whole did not soften and melt during heating, thus failing to effectively encapsulate the functional material. The phase change microcapsules were squeezed out of the cavities during hot pressing, accumulating in large quantities on the fabric surface and in the interlayer gaps, resulting in an actual filling rate of less than 40% within the cavities. Simultaneously, due to the lack of a molten sheath at the nodes, the friction between the yarns was insufficient, making the nodes prone to slippage. Tested with a YG(B)026D fabric strength tester, the Z-axis peel strength of the fabric was only 12.5 N / cm, a decrease of 65.2% compared to Example 1. Furthermore, the unmelted, stiff yarn made the fabric feel rough and stiff, unable to form dense cavity walls, resulting in a functional material leakage rate of 38% after 30 days of accelerated aging testing.

[0078] In summary, Comparative Example 1 showed significant deterioration across all four key indicators. The Z-axis peel strength decreased by 65.2%, indicating insufficient bonding strength at the nodes due to the coreless yarn structure. The 59.3% decrease in functional material filling rate and the 3100% surge in leakage rate indicate the severity of encapsulation failure. The nearly eight-fold increase in node slippage rate indicates a near-complete loss of structural stability.

[0079] Therefore, ordinary yarns cannot achieve selective melt encapsulation, resulting in loss of functional materials, poor node bonding, insufficient structural stability, and a complete loss of the ability to integrate "structure and function".

[0080] Comparative Example 2

[0081] The warp yarns use a uniform core-sheath ratio and the same melting point. Specifically, the first and second warp yarns both use the same core-sheath yarn with a core-sheath volume ratio of 40 / 60 and a core melting point of 160°C. The remaining process parameters (weaving, injection, hot pressing) are completely consistent with those in Example 1 of this invention.

[0082] Test Project Embodiment 1 of the present invention Comparative Example 2 Performance changes Cavity height retention rate (%) 98.5 67.7 -31.2% Cavity ratio (%) 0.8 21.7 +2613% Shear strength (MPa) 32.8 18.3 -44.2% Performance consistency CV value (%) 3.2 15.8 +394%

[0083] Table 2

[0084] As shown in Table 2, when heated to 160℃, all warp yarn skins melted simultaneously, causing both Z- and Y-axis yarns to soften concurrently. Because the first Z-axis warp yarn failed to be preferentially set, it underwent significant creep under gravity and pressure, resulting in a 32.3% compression rate in the nine-grid cavity, leading to structural collapse and deformation. Simultaneously, the molten skin flowed disorderly among the yarns, connecting some central cavities with peripheral cavities, causing cross-contamination of functional materials. Micro-CT scanning revealed a cross-contamination rate of 21.7%. Although the fabric was ultimately "bonded," the nodes exhibited a flattened shape due to excessive yarn softening, resulting in a decrease in shear strength to 18.3 MPa (tested according to ISO 14129), a 44.2% reduction compared to Example 2. Furthermore, the uneven distribution of functional materials in the central region due to structural collapse resulted in a coefficient of variation (CV) of 15.8% for performance consistency.

[0085] In summary, the 31.2 percentage point drop in cavity height retention rate in Comparative Example 2 is directly related to the 26-fold increase in cavity crosstalk rate, indicating that synchronous melting leads to both structural support failure and deterioration of sealing performance. The 44.2% decrease in shear strength confirms the mechanical degradation caused by excessive softening of the nodes, while the nearly four-fold increase in the performance consistency CV value quantitatively reveals the severity of uneven distribution of functional materials. This clearly reflects the crucial role of differentiated core-skin design in maintaining structural stability.

[0086] Therefore, the design of warp yarn core-to-sheath ratio and melting point is not differentiated, which makes it impossible to form a priority shaping mechanism, which easily leads to structural collapse, cavity leakage and mechanical property deterioration, and loses the synergistic effect of "central rigidity and peripheral toughness" of the present invention.

[0087] Comparative Example 3

[0088] A single positive interlocking node design is adopted (the second type of wrapping node is eliminated). Specifically, at all nine cavity nodes of the nine-grid structure, the same first type of positive interlocking method as the central node is used (i.e., all Z-axis yarns interweave and fold back with the Y-axis yarns), eliminating the 30°–60° non-orthogonal wrapping design. The yarn and injection parameters are the same as in Example 1.

[0089] Test Project Embodiment 1 of the present invention Comparative Example 3 Performance changes Elongation at break (%) 41.1 18.5 -55.0% Impact energy absorption rate (J / g) 100.8 42.3 -58.0% Strength retention rate after 100 thermal cycles (%) 95.8 72.4 -24.4% Node fatigue damage index 1.2 8.7 +625%

[0090] Table 3

[0091] As shown in Table 3, although the initial binding force of all nodes was high, the overall stiffness of the fabric was too large. Tested with a YG(B)026D fabric strength tester, the elongation at break decreased to 18.5%, a reduction of 54.9% compared to Example 1. In the dynamic impact test (according to GB / T21189-2007 standard, impact energy 5J), due to the lack of structural deformation capacity of the peripheral nodes, stress could not be effectively dispersed, and the energy absorption rate was only 42.3J / g, a reduction of 58.1% compared to Example 1, exhibiting brittle fracture characteristics. Simultaneously, the tight structure of the positive interlocking structure restricted the microflow space of the functional material under pressure, causing the phase change material to repeatedly compress the yarn due to volume expansion during cyclic phase change, accelerating fatigue damage at the core-sheath interface. After 100 thermal cycles (20–60℃), the node strength retention rate decreased to 72.4%, while Example 1 still maintained 95.8%.

[0092] In summary, the single-node design reduced both elongation at break and impact energy absorption rate by nearly 55%, confirming that excessive rigidity of the peripheral nodes led to loss of toughness and failure of energy buffering. The thermal cycling strength retention rate decreased by 24.4 percentage points, and combined with a more than 6-fold increase in the fatigue damage index, quantitatively revealing the insufficient adaptability of the positive interlocking design to the expansion of functional materials. This demonstrates the necessity of differentiated node designs for balancing "rigidity-toughness" performance; a single structure cannot simultaneously achieve central stability and peripheral impact resistance.

[0093] Therefore, while a single positive interactive locking node improves static strength, it sacrifices peripheral toughness and energy buffering capacity, and is not conducive to the long-term stable operation of functional materials, thus failing to achieve "rigid-toughness" partitioning optimization.

[0094] Comparative Example 4

[0095] A magnetorheological fluid with no volume gradient is uniformly injected into the cavity. Specifically, an equal volume (1.0 times the designed volume of the central cavity) of magnetorheological fluid (viscosity 200 mPa·s, solid content 50%) is injected into all nine cavities of the nine-grid structure, and the remaining processes are the same as in Example 1 of this invention.

[0096] Test Project Embodiment 1 of the present invention Comparative Example 4 Performance changes Magnetic field response sensitivity (%) 100 61.3 -38.7% Functional material leakage rate (%) 0.5 12.4 +2380% Temperature difference between center and periphery response (°C) 4.5 1.8 -60.0% Functional material utilization rate (%) 98.2 85.7 -12.7%

[0097] Table 4

[0098] As shown in Table 4, due to the inherent difference in structural reinforcement between the central and peripheral nodes, uniform injection resulted in insufficient functional material in the central region, limiting its performance. Using a Physica MCR301 rheometer, the magnetic field response sensitivity (shear stress change rate) was only 61.3% of that in Example 1. Simultaneously, due to the relatively excessive injection volume in the peripheral cavity, excess magnetorheological fluid seeped out from the micro-gaps in the cavity walls during hot-pressing curing, contaminating the fabric surface and wasting material, with a seepage rate of 12.4%. Ultimately, the fabric exhibited "averaged" performance, failing to form a "core-periphery" gradient functional field. Infrared thermal imaging testing showed that the response temperature difference between the central and peripheral regions was only 1.8℃, while in Example 1 it reached 4.5℃, indicating a loss of intelligent gradient control capability.

[0099] In summary, uniform injection reduced the magnetic field response sensitivity by nearly 40%, directly weakening the driving efficiency of smart materials. The 23.8-fold increase in exudation rate and the 12.7% decrease in utilization rate correspond, indicating that excessive injection leads to material waste and sealing failure. The 60% reduction in the temperature difference between the center and periphery quantitatively demonstrates the disappearance of the gradient functional field. These findings clearly validate the crucial role of the volume gradient injection strategy in achieving differentiated "core-periphery" performance from three levels: functional response, material efficiency, and gradient distribution.

[0100] Therefore, the gradientless injection strategy cannot match the differentiated node structure, resulting in low utilization of functional materials and lack of gradient effect.

[0101] Comparative Example 5

[0102] After the first warp yarn skin layer melts, the fabric is placed in a room temperature environment of 25°C for natural cooling, without using a cold airflow or coagulation liquid at 5–15°C. The curing time is extended to more than 30 seconds (cooling rate of about 0.5°C / s), and the other parameters are the same as in Example 1.

[0103] Test Project Embodiment 1 of the present invention Comparative Example 5 Performance changes Cooling rate (°C / s) 8.5 0.5 -94.1% Cavity ratio (%) 0.9 16.3 +1711% Water washing material loss rate (%) 1.8 24.7 +1272% Node solder joint diameter (mm) 0.3 0.8 +167%

[0104] Table 5

[0105] As shown in Table 5, due to the slow cooling rate, the molten skin continued to flow before solidification, causing some functional materials (phase change microcapsule slurry, viscosity 150 mPa·s) to deposit towards the bottom of the cavity under gravity and slowly migrate to adjacent cavities through the micro-gaps in the incompletely solidified cavity wall. Fluorescent labeling analysis showed a cross-cavity rate of 16.3%. Simultaneously, slow cooling reduced the crystallinity of the skin layer, resulting in poor encapsulation density. After a water washing test (GB / T3921-2008), the functional material loss rate reached 24.7%. Furthermore, because the melt could not be quickly positioned at the yarn interlacing points, some nodes exhibited excessively large "weld points" (average diameter of 0.8 mm, compared to 0.3 mm in Example 1). Localized hardening led to uneven fabric hand feel, and the bending stiffness CV value reached 18.5%.

[0106] In summary, a 94.1% reduction in cooling rate directly led to a 17-fold increase in crosstalk rate and a 12.7-fold increase in material loss rate, showing a significant positive correlation between the two, confirming the destructive effect of slow curing on encapsulation sealing. The 167% increase in node solder joint diameter, combined with the significant fluctuation in bending stiffness (CV), quantitatively revealed the deterioration of structural uniformity caused by disordered melt flow. This demonstrates the necessity of rapid re-curing processes in preventing functional material migration and ensuring cavity independence from the perspectives of curing kinetics, encapsulation integrity, and geometric accuracy.

[0107] Therefore, the lack of rapid re-curing methods leads to easy leakage and cross-contamination of functional materials, poor encapsulation quality, and a significant reduction in process stability and product reliability.

[0108] Comparative Example 6

[0109] After the functional material injection and skin melting encapsulation are completed, the weft yarn binding and hot pressing reinforcement steps are omitted, and the fabric is only cold-pressed at 0.5MPa for 60 seconds at room temperature.

[0110] Test Project Embodiment 1 of the present invention Comparative Example 6 Performance changes Z-axis shear strength (MPa) 18.3 8.7 -52.5% Cavity deformation rate after 10 bending cycles (%) 3.1 23.4 +655% 90-day accelerated aging leakage rate (%) 2.1 18.9 +800% Interlayer peel strength (N / cm) 28.5 11.2 -60.7%

[0111] Table 6

[0112] As shown in Table 6, due to the lack of applied thermal pressure, the first warp yarn skin only underwent preliminary melting and encapsulation, resulting in insufficient fusion between yarns and weak interlayer bonding. Tested according to ASTM D3846, the fabric's Z-axis shear strength was only 8.7 MPa, a 52.5% decrease compared to Example 1, and it was prone to delamination during use. Simultaneously, the weft yarns did not undergo thermal tightening, leading to loose yarns at the nodes and poor structural stability. After 10 bending cycles (bending radius 10 mm), the deformation rate of the nine-grid cavity reached 23.4%. Furthermore, the lack of thermal action prevented the residual solvent from completely evaporating, resulting in insufficient re-solidification of the skin and poor encapsulation durability. After 90 days of accelerated aging (temperature 50℃, humidity 95%), the functional material leakage rate reached 18.9%.

[0113] In summary, omitting hot-compression strengthening resulted in a 52.5% decrease in Z-axis shear strength and a 60.7% decrease in interlaminar peel strength, with similar reductions, jointly confirming the strengthening mechanism of interlaminar fusion through thermal action. The 6.5-fold increase in bending cavity deformation rate, combined with an 8-fold increase in leakage rate, quantitatively reveals the synergistic deterioration effect of node relaxation and poor encapsulation. These data, from the perspectives of mechanical properties, structural stability, and long-term durability, clearly demonstrate the indispensability of hot-compression strengthening in locking the node structure and improving overall strength.

[0114] Therefore, the lack of heat-pressing reinforcement results in poor mechanical properties, loose structure, and weak sealing of the fabric, which cannot meet the durability requirements of practical applications.

[0115] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, apparatus, article, or 3D fabric forming process that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or 3D fabric forming process. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or 3D fabric forming process that includes that element.

[0116] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A process for forming a nine-square grid three-dimensional fabric, characterized in that, Includes the following steps: S1. Provide a first warp yarn, a second warp yarn, and a weft yarn, wherein the first warp yarn and the second warp yarn are both core-sheath structures, and the melting point or dissolution temperature of the sheath layer is 20–80°C lower than that of the core layer; S2. The first warp yarn is laid out along the thickness direction of the fabric, the second warp yarn is laid out along the length direction of the fabric, and the weft yarn is laid out along the width direction of the fabric to form a three-dimensional skeleton prototype with no less than 3 layers. S3. Within the three-dimensional skeleton prototype, a three-dimensional orthogonal or angular interlocking structure is used for weaving. The first warp yarn in the Z direction binds the weft yarn in the X direction and the second warp yarn in the Y direction to form a nine-square grid structure with at least a 3×3 array cavity. S4. At the cavity node located at the geometric center, the center yarn of the first warp yarn is interlaced, folded back, and wrapped around the center yarn of the second warp yarn to form a first type of positive interlocking node; at the eight peripheral cavity nodes surrounding the central node, the upper and lower yarns of the first warp yarn are wrapped around the left and right yarns of the second warp yarn at non-orthogonal angles to form a second type of surrounding binding node; S5. After the cavity is formed and before the node structure is completely tightened and fixed, inject functional material into the cavity; S6. The skin of the first warp yarn is melted by heating or dissolved by solvent, and then re-cured or solidified to enclose the functional material inside the cavity of each unit. S7. Use the weft yarn to tie each node and apply a heat pressure of 0.2–0.8 MPa to the fabric to reinforce it.

2. The nine-grid three-dimensional fabric forming process according to claim 1, characterized in that, The melting of the first warp yarn skin layer is induced by hot pressing, and then solidified by blowing with a cold airflow of 5–15°C for 0.5–2 seconds; the dissolution of the first warp yarn skin layer is solidified by spraying 5–10wt% CaCl2 or NaCl aqueous solution at 0.05–0.2 g / cm².

3. The nine-grid three-dimensional fabric forming process according to claim 2, characterized in that, The first warp yarn has a core-sheath volume ratio of 30 / 70–50 / 50 and a sheath melting point or dissolution temperature ≤180℃; the second warp yarn has a core-sheath volume ratio of 20 / 80–40 / 60 and a sheath melting point or dissolution temperature 10–30℃ higher than that of the first warp yarn.

4. The nine-grid three-dimensional fabric forming process according to claim 3, characterized in that, The first warp, the second warp, and the weft yarn are all made of monofilament, multifilament, air-textured yarn, or core-spun yarn, with a yarn density of 2–20 tex.

5. The nine-grid three-dimensional fabric forming process according to claim 4, characterized in that, The breaking strength of the first warp yarn, the second warp yarn, and the weft yarn is not less than 10 cN / tex, and the initial modulus is not less than 20 GPa.

6. The nine-grid three-dimensional fabric forming process according to claim 1, characterized in that, The volume of the functional material injected into the central cavity is 1.5–2.0 times that of the volume injected into the outer cavity, and the viscosity of the functional material at a shear rate of 10 s⁻¹ is 50–500 mPa·s.

7. The nine-grid three-dimensional fabric forming process according to claim 6, characterized in that, After molding, the dimensions of the central cavity in the X, Y, and Z directions are 1.1–1.4 times the dimensions of the corresponding directions of the outer cavity.

8. The nine-grid three-dimensional fabric forming process according to claim 1, characterized in that, In step S7, the applied temperature of the thermal pressure is 50–120°C, and the holding time is 30–180 seconds.

9. The nine-grid three-dimensional fabric forming process according to claim 1, characterized in that, In step S6, after the skin melts or dissolves, the rate of re-solidification or solidification is not less than 5°C / s.

10. The nine-grid three-dimensional fabric forming process according to claim 1, characterized in that, In step S5, the injected functional material is a liquid, a gel, or a phase change material microcapsule with a phase change temperature ≤100℃.

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