Hollow warm-keeping yarn fabric

Abstract

The invention relates to the related technical field of warm-keeping fabrics, in particular to a hollow warm-keeping yarn fabric which is formed by weaving hollow fibers in a staggered plaid structure, the staggered plaid structure is formed by interweaving warp yarns and weft yarns in a spiral winding mode, and micro air chambers are formed at the interweaving points of the warp yarns and the weft yarns. The hollow fiber comprises a core layer and a sheath layer, the core layer is of a plum blossom petal-shaped multi-cavity structure formed by ultra-high molecular weight polyethylene, cavities are separated through radial connecting bridges, and the sheath layer sequentially comprises a heat conduction enhancing layer, an infrared reflecting layer and a dynamic temperature adjusting layer from inside to outside. Dynamic heat and humidity collaborative management, intelligent temperature response, radiation heat management and structural stability are effectively improved, the heat retention property and moisture permeability of the fabric are improved, self-adaptive adjustment can be achieved according to the body temperature of the human body, the heat radiation transmission efficiency is enhanced, the super-hydrophobic interface modification and covalent bonding technology is adopted, and the thermal radiation performance of the fabric is improved. And the functional layer can still keep high bonding strength after being washed repeatedly.

Description

Technical Field

[0001] The present invention belongs to the technical field related to thermal insulation fabrics, and more specifically, particularly relates to a hollow thermal insulation yarn fabric. Background Art

[0002] The research and development of thermal insulation materials has always centered around the suppression of the three major heat loss mechanisms: heat conduction, convection, and radiation. After multiple technological iterations in the traditional material system, the main technical routes include: 1. Natural thermal insulation materials. Natural materials such as down and cotton wool rely on the static air layer formed between fibers for heat insulation. Although such materials have a relatively high thermal resistance value, they have obvious defects: moisture absorption and caking: after the fibers absorb moisture, the fluffiness decreases, and the thickness of the air layer decreases, resulting in a sudden reduction in thermal resistance; poor moisture permeability: the dense structure hinders the discharge of moisture, easily causing sweat retention and leading to a cold feeling; mechanical fragility: there is no stable connection structure between the fibers, and it is difficult to recover the initial shape after repeated compression.

[0003] 2. Synthetic hollow fibers. Synthetic fibers such as polyester and polypropylene store air through single-chamber or multi-chamber hollow structures to improve the heat insulation performance. Although such materials have improved moisture resistance, they are limited by: enhanced convection effect: the air inside a single cavity is prone to form micro-convection, which instead accelerates heat conduction; functional simplification: lacking an active thermal management mechanism and unable to respond to changes in environmental temperature and humidity; risk of structural collapse: thin-walled hollow fibers are prone to cavity closure when bent or compressed.

[0004] 3. Composite functional materials. In recent years, additional functions have been imparted to materials by coating a reflective layer (such as a metal coating), adding phase change microcapsules (PCMs), or introducing conductive fillers. However, such technologies face common bottlenecks: weak interfacial bonding: due to differences in thermal expansion coefficients between heterogeneous material layers, peeling is likely to occur; functional cancellation effect: for example, the reflective layer hinders the escape of moisture, resulting in deteriorated moisture permeability; insufficient durability: the functional components are prone to loss or failure during washing or friction.

[0005] Based on the above technical evolution context, the existing material system still has systematic defects when facing extreme environments such as high cold and high humidity: Fragmented thermal management mechanism: functional modules such as heat insulation, moisture permeability, and reflection are independent of each other and lack synergistic effects; Lack of dynamic response: unable to adjust the direction and rate of heat flow in real time through structural or compositional changes; Durability contradiction: functional composite often comes at the cost of sacrificing mechanical properties or washability. Summary of the Invention

[0006] The purpose of the present invention is to provide a hollow thermal insulation yarn fabric to solve the problems raised in the above background art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions: A hollow thermal insulation yarn fabric, wherein the fabric is woven from hollow fibers in an interlaced lattice structure, the interlaced lattice structure is formed by the warp yarns and the weft yarns being interwoven in a spiral winding manner, and micro air chambers are formed at the intersection points of the warp yarns and the weft yarns. The hollow fiber includes a core layer and a sheath layer. The core layer is a plum blossom petal-shaped multi-chamber structure formed by ultra-high molecular weight polyethylene, and the cavities are separated by radial connecting bridges. The sheath layer is sequentially a heat conduction enhancement layer, an infrared reflection layer, and a dynamic temperature regulation layer from the inside to the outside.

[0008] It should be noted that when the warp and weft yarns are spirally interwoven, the gaps between the fibers form closed micro air chambers, reducing heat convection through air retention and enhancing the thermal insulation performance. The core layer is a plum blossom petal multi-chamber structure of ultra-high molecular weight polyethylene. Ultra-high molecular weight polyethylene provides good mechanical support, and the multi-chamber structure further divides the air flow path, reducing the thermal conductivity coefficient. The sheath layer is a three-layer composite structure. The heat conduction enhancement layer directionally conducts heat to take away the moisture on the body surface. The infrared reflection layer blocks external thermal radiation. The dynamic temperature regulation layer adjusts the temperature fluctuation by phase change heat absorption / release. Generally speaking, the multi-chamber structure of the core layer reduces heat conduction by dividing the air flow path, while the sheath layer realizes dynamic thermal management through gradient functional design (heat conduction - reflection - temperature regulation).

[0009] A further technical solution is that the heat conduction enhancement layer is a graphene quantum dot grafted thermoplastic polyurethane composite layer, the graphene quantum dots are axially oriented along the fiber axis, the infrared reflection layer is a blend layer of liquid crystal polymer and hydrophobic modified boron nitride, the boron nitride is distributed in a sheet-like manner parallel to the fiber surface, the dynamic temperature regulation layer contains a thermally induced shape memory polymer with phase change microcapsules, the wall material of the microcapsules is nano-silica coated with polydopamine, the graphene quantum dots of the heat conduction enhancement layer and the boron nitride sheets of the infrared reflection layer form a continuous heat conduction path, and the phase change microcapsules of the dynamic temperature regulation layer and the thermally induced shape memory polymer act synergistically to achieve a dynamic balance of heat absorption - storage - release.

[0010] It should be noted that for the heat conduction enhancement layer, graphene quantum dots (GQDs) are grafted onto thermoplastic polyurethane (TPU), and the GQDs are axially oriented. Its mechanism is that the sp² hybrid carbon structure of GQDs is axially arranged, similar to the lattice orientation in optical fibers, forming a continuous heat conduction path. The size effect of GQDs (<10 nm) enhances the phonon transfer efficiency and reduces the interfacial thermal resistance. The heat conduction enhancement layer can quickly conduct out the latent heat of evaporation of sweat on the body surface, and cooperate with the infrared reflection layer to achieve unidirectional heat conduction (inside the body → outside the body), avoiding the cold feeling caused by reverse temperature difference.

[0011] Infrared reflective layer, liquid crystal polymer (LCP) + hydrophobically modified boron nitride (h-BN). The h-BN flakes are arranged in parallel. The mechanism is that the hexagonal lattice of h-BN has a reflectivity of ≥85% in the 8-14 μm band (the peak wavelength of human radiation is about 9.5 μm). The hexagonal lattice structure of h-BN has a high reflectivity to infrared rays in the 8-14 μm band, effectively blocking the loss of human body heat radiation. When LCP is melt-spun, shear orientation occurs, and the molecular chains are oriented by shear force, forcing the h-BN flakes to be arranged in parallel, forming a reflective structure similar to a shutter to reflect infrared rays incident at various angles.

[0012] Dynamic temperature regulation layer, phase change microcapsules (PCMs) of polydopamine-coated SiO2 + thermally induced shape memory polymer (SMP). SMP can recover the preset shape at a specific temperature, thus changing the fabric structure. Heat storage / release of PCMs: The core material of the microcapsules is octadecane, and the wall material is polydopamine-SiO2; Deformation response of SMP: SMP (such as polycaprolactone type) undergoes a glass transition near body temperature (30-40 °C), and changes the fabric porosity and regulates the air permeability by curling / stretching. PCMs buffer the temperature mutation by absorbing heat during phase change, while SMP dynamically adjusts the fabric porosity according to temperature changes, and the two jointly achieve a closed-loop regulation of 'heat absorption - energy storage - heat dissipation'.

[0013] A further technical solution is that the inner wall of the cavity of the plum blossom petal-shaped multi-cavity structure is loaded with a temperature-sensitive polymer brush, and the polymer brush undergoes a conformational change in the temperature range of 25-35 °C to regulate the effective heat conduction area of the cavity.

[0014] It should be noted that the temperature-sensitive polymer brush is specifically: The inner wall of the cavity is grafted with poly(N-isopropylacrylamide) (PNIPAM), and the LCST (lower critical solution temperature) is 32 °C. The LCST of PNIPAM is set at 32 °C, which is close to the human body surface temperature to achieve body temperature self-adaptive regulation. When the temperature is lower than 32 °C, the molecular chains of PNIPAM stretch (hydrophilic state), covering the cavity wall to reduce the heat radiation area; when the temperature is higher than 32 °C, the molecular chains curl (hydrophobic state), exposing more cavity surfaces to enhance heat convection heat dissipation. The change of the temperature-sensitive polymer brush dynamically adjusts the heat conduction area of the cavity, forming a complement with the static multi-cavity structure of the core layer to enhance the flexibility of temperature control.

[0015] A further technical solution is that the fineness of the single filament of the hollow fiber is adapted to the plum blossom petal-shaped multi-cavity structure, so that the fiber can maintain the integrity of the cavity while meeting the processability of spinning, and the fiber wall thickness is configured to be 10%-15% of the single filament diameter to ensure that the anti-bending strength is ≥4.5 cN / dtex.

[0016] It should be noted that the fineness of the single filament of the hollow fiber is 2-3 dtex. The melt differential electrospinning technology is used to achieve an ultra-thin wall thickness, and the wall thickness is 10%-15% of the diameter (about 0.5-0.8 μm). The plum blossom petal structure disperses stress through radially connected bridges. By analogy with the honeycomb structure, the compressive strength is effectively improved, and the anti-bending strength is close to the mechanical properties of aramid fibers.

[0017] In a further technical solution, the nano-silica is subjected to two-step modification treatment. First, amino active sites are introduced through a silane coupling agent, and then reacted with a perfluorosilane to form a superhydrophobic surface. The water contact angle after modification is ≥150°, and the surface energy is ≤20 mN / m.

[0018] It should be noted that the perfluorosilane is perfluorooctyltriethoxysilane (FAS). The modification process of nano-SiO2: amino-functionalization with KH550 silane coupling agent → hydrophobization with perfluorooctyltriethoxysilane (FAS). Its internal chemical mechanism is the ring-opening reaction of the amino group with the epoxy group of FAS to form a Si-O-Si covalent bond and graft a perfluoroalkyl chain to achieve a superhydrophobic and superoleophobic effect (both water / oil contact angles >150°). The reaction formula is: SiO2-NH2 + FAS → SiO2-Si-(CH2)2-C8F17. The superhydrophobic wall material improves the washability of the phase change microcapsules and prevents the leakage of the core material.

[0019] In a further technical solution, in the infrared reflection layer, the hydrophobic modified boron nitride forms a covalent bonding interface with the liquid crystal polymer through a silane coupling agent, and a fluorine-containing flame retardant is grafted on the surface of the boron nitride to form a hydrophobic-flame retardant bifunctional nanosheet.

[0020] It should be noted that the silane coupling agent covalently bonds with LCP + grafts decabromodiphenylethane (flame retardant). h-BN is treated with KH560, and the surface epoxy group reacts with the terminal carboxyl group of LCP, and the interfacial shear strength is increased to ≥25 MPa (only 8-10 MPa for physical mixing). The grafting of the flame retardant increases the limiting oxygen index (LOI) of h-BN from 21% to 32%.

[0021] In a further technical solution, the warp and weft of the staggered lattice structure are interwoven at an angle of 45-60°, forming a gradient pore size distribution, where the pores with a pore size of 50-100 μm account for ≥70%. When the gram weight is 80-120 g / ㎡, the air permeability is ≥500 mm / s and the thermal resistance value is ≥0.5 clo.

[0022] In a further technical solution, a polyurethane-based anti-feather leakage layer is compounded on the back of the fabric. The thickness of the anti-feather leakage layer is 5-10 μm, and the coverage area ratio is ≤15%.

[0023] It should be noted that polyurethane is compounded on the back of the fabric in the form of a micro-lattice through electrospinning, and the fluff is adsorbed by viscoelasticity.

[0024] According to a further technical solution, the sheath layer also contains 0.5%-3% by mass of graphene sheets, the lateral size of the graphene sheets is 1-5 μm, the thickness is ≤5 nm, and they are arranged in a directional parallel manner in the TPU matrix. The mass ratio of the graphene sheets to nano-silicon dioxide is 1: (2-5), and the angle between the long axis of the graphene sheets and the axial direction of the fiber is ≤15°.

[0025] It should be noted that graphene forms a three-dimensional thermal conductive network in TPU, forming a synergistic effect with SiO2: SiO2 fills the gaps between graphene sheets to reduce interfacial thermal resistance, graphene / SiO2 composite reinforcement improves the wear resistance of the fiber, and the angle between the long axis of the graphene sheet and the axial direction of the fiber is ≤15°, ensuring efficient transmission of phonons along the axial direction of the fiber.

[0026] A further technical solution is that far-infrared ceramic powder is also dispersed in the sheath layer, and the ceramic powder is a composite of magnesium germanate and titanium dioxide, with a particle size of 0.1-1 μm, a mass ratio of 2-8%, and a far-infrared emissivity of ≥0.88. The surface of the far-infrared ceramic powder is coated with a nano-silicon dioxide layer, and the coating thickness is 5%-10% of the ceramic particle size.

[0027] It should be noted that the far-infrared ceramic material: magnesium germanate (Mg2GeO4) / TiO2 composite ceramic, the SiO2 coating layer is 50-100 nm thick, the lattice vibration of Mg2GeO4 has an emissivity of ≥0.88 in the 4-14 μm band (close to 0.9 of human body radiation), the [GeO4] tetrahedron vibration of Mg2GeO4 resonates with the far-infrared band of the human body, enhancing thermal radiation transfer, and transferring heat through resonant absorption-reradiation. The SiO2 coating layer reduces ceramic surface defects and improves infrared emission stability. In addition, the coated ceramic powder slows down the attenuation of emissivity after washing.

[0028] Compared with the prior art, the present invention has the following beneficial effects: Dynamic heat and moisture coordinated management: The unique multi-cavity plum petal structure combined with gradient pore size distribution effectively suppresses air convection while promoting directional moisture discharge, achieving dual optimization of warmth retention and moisture permeability; the axially oriented thermal conductive layer and the infrared reflective layer work together to form a unidirectional heat transfer path, significantly reducing the feeling of coldness caused by the inverse temperature difference.

[0029] Intelligent temperature response: The composite design of phase change microcapsules and shape memory polymers endows the material with dynamic temperature regulation capabilities of heat absorption, energy storage and release, which can buffer sudden changes in ambient temperature; the conformational transition characteristics of the thermosensitive polymer brushes further realize the adaptive regulation of body temperature of the cavity thermal conductivity area.

[0030] Enhanced radiative heat management: The oriented boron nitride sheets form a mirror-like reflection structure, significantly improving the reflection efficiency in the mid-infrared band; the far-infrared ceramic composite layer enhances the thermal radiation transfer efficiency through the resonance absorption-re-radiation mechanism.

[0031] Improved structural stability: The plum blossom petal cavity design of the radial connecting bridges disperses stress concentration, significantly enhancing the fiber's resistance to bending; the superhydrophobic interface modification and covalent bonding process ensure that the functional layer maintains high bonding strength after repeated washing. Brief Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] The present invention will be further described below in conjunction with the drawings and embodiments.

[0034] Figure 1 It is a comparison chart of the test results of the thermal resistance values of Examples 1-5 and Comparative Examples 1-3 in the present invention; Figure 2 It is a comparison chart of the test results of the axial thermal conductivity coefficients of Examples 1-5 and Comparative Examples 1-3 in the present invention; Figure 3 It is a comparison chart of the test results of the infrared reflectance of Examples 1-5 and Comparative Examples 1-3 in the present invention; Figure 4 It is a comparison chart of the four performance indicators of Examples 1-5 and Comparative Examples 1-3 in the present invention. Detailed Description of the Embodiments

[0035] The following will further describe in detail the embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0036] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the present invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and enable those of ordinary skill in the art to understand the present invention and thus design various embodiments with various modifications suitable for specific purposes. Embodiment

[0039] Preparation of the core layer (UHMWPE plum blossom petal multi-cavity structure) Raw materials: Ultra-high molecular weight polyethylene (UHMWPE, molecular weight 5×10 6 g / mol) Equipment: Customized 5-cavity microporous spinning nozzle, twin-screw melt spinning machine.

[0040] Process steps: The UHMWPE particles are dried under nitrogen protection (120 °C, 4 h), added to the twin-screw extruder, the die head temperature is set at 240 °C, the screw speed is 60 rpm, and the extrusion pressure is 12 MPa. The melt is extruded through a customized five-cavity plum blossom petal nozzle (hole diameter 0.2 mm, cavity spacing 50 μm). The draw ratio is 5 times, the cooling water temperature is 25 °C, and the winding speed is 800 m / min. Finally, the fibers are heat-set (130 °C, 30 s) to stabilize the cavity structure.

[0041] Sheath layer composite process Preparation of the thermal conductivity enhancement layer (GQDs / TPU): Materials: TPU, graphene quantum dots (GQDs, diameter 5 nm) Process: GQDs and TPU are dissolved in DMF at a mass ratio of 1:100 and ultrasonically dispersed for 1 h (power 300 W). The solution is wet-spun through a spinneret with a hole diameter of 0.15 mm, drawn 3 times, and the GQDs are aligned directionally by an axial magnetic field (0.5 T).

[0042] Preparation of the infrared reflection layer (LCP / h-BN): Materials: LCP, hydrophobically modified h-BN (particle size 1 μm) Process: h-BN and LCP are mixed at a mass ratio of 15:85 and extruded by a twin-screw extruder (temperature 320 °C, screw speed 40 rpm). The melt is extruded into a film through a slit die (thickness 20 μm) and roll-pressed for orientation (drawing ratio 4:1).

[0043] Preparation of the dynamic temperature-regulating layer (PCMs / SMP): Materials: Phase change microcapsules (core material octadecane, shell material polydopamine / SiO2, particle size 10 μm), thermally induced SMP (polycaprolactone type, Tg = 35 °C) Process: PCMs and SMP are melt-blended at a mass ratio of 30:70 (180 °C, 30 min). They are coated on the fiber surface by electrospinning (voltage 15 kV, receiving distance 15 cm), and the coating thickness is 50 μm.

[0044] Fabric weaving and post-treatment Equipment: Rapier loom, ion processor with a spiral winding angle of 55°.

[0045] Process steps: Warp density 60 threads / cm, weft density 55 threads / cm, intersection point spacing 0.5 mm, spiral winding angle 55°, forming a gradient pore size (surface layer 50 μm, inner layer 100 μm).

[0046] Down-proof treatment: Polyurethane dot spraying (coverage rate 12%), thickness 8 μm.

[0047] Functional finishing: Padding with far-infrared ceramic slurry (Mg2GeO4 / TiO2, solid content 20%) (padding rate 80%), drying (110 °C, 3 min).

[0048] Key parameters of Example 1: Core layer: Five-chamber plum blossom petal structure (pore diameter 0.2 mm, chamber spacing 50 μm).

[0049] Thermal conductive layer: Mass ratio of GQDs / TPU 1:100, h-BN content 15%, PCMs content 30%.

[0050] Process parameters: Spinning temperature 240 °C, drawing ratio 5 times, magnetic field strength 0.5 T.

[0051] Key parameters of Example 2: Core layer: Three-chamber plum blossom petal structure (pore diameter 0.25 mm, chamber spacing 80 μm).

[0052] Thermal conductive layer: Mass ratio of GQDs / TPU 1:100, h-BN content 15%, PCMs content 30%.

[0053] Process parameters: Spinning temperature 240 °C, drawing ratio 5 times, magnetic field strength 0.5 T.

[0054] Key parameters of Example 3: Core layer: Seven-chamber plum blossom petal structure (aperture 0.15 mm, chamber spacing 30 μm).

[0055] Thermal conductive layer: Mass ratio of GQDs / TPU 1:100, h-BN content 15%, PCMs content 30%.

[0056] Process parameters: Spinning temperature 240 °C, draw ratio 5 times, magnetic field strength 0.5 T.

[0057] Key parameters of Example 4: Core layer: Five-chamber plum blossom petal structure (aperture 0.2 mm, chamber spacing 50 μm).

[0058] Thermal conductive layer: Mass ratio of GQDs / TPU 0.5:100, h-BN content 15%, PCMs content 30%.

[0059] Process parameters: Spinning temperature 240 °C, draw ratio 5 times, magnetic field strength 0.5 T.

[0060] Key parameters of Example 5: Core layer: Five-chamber plum blossom petal structure (aperture 0.2 mm, chamber spacing 50 μm).

[0061] Thermal conductive layer: Mass ratio of GQDs / TPU 2:100, h-BN content 15%, PCMs content 30%.

[0062] Process parameters: Spinning temperature 240 °C, draw ratio 5 times, magnetic field strength 0.5 T.

[0063] Test dimensions and data comparison 1. Core performance indicators Test Item Test Standard Test Equipment / Method Void Ratio SEM Image Analysis Field Emission Scanning Electron Microscope (SEM) Thermal Resistance Value (clo) ASTM D1518 Hot Plate Method (Steady-State Heat Flow Test) Axial Thermal Conductivity Transient Plane Heat Source Method Thermal Conductivity Analyzer (Transient Plane Heat Source Method) Infrared Reflectivity FTIR Integral Reflectivity Fourier Transform Infrared Spectrometer (8 - 14 μm Band) Phase Change Enthalpy (J / g) DSC Test Differential Scanning Calorimeter (DSC) Flexural Strength GB / T 3916 Electronic Fabric Strength Tester (Constant Rate Tensile) 2. Test data comparison table Based on the actual experimental error, the average value of 3 tests ± standard deviation is taken for each group of data. Regarding the treatment of outliers, if a single test deviates from the mean by more than 10%, it is marked as an outlier and excluded. Comparative Example 1 Core layer: Single-chamber UHMWPE (aperture 0.3 mm, without plum blossom petal cavity structure).

[0064] Sheath layer: Only pure TPU outer layer (without thermal conductive layer, without infrared reflection layer, without dynamic temperature regulation layer).

[0065] Preparation process: Conventional melt spinning (without magnetic field orientation, without LCP shear orientation) Test results of Comparative Example 1: Test Item Data Analysis Thermal Resistance Value (clo) 0.26±0.05 Air Convection in the Single-Cavity Structure is Significantly Enhanced Thermal Conductivity (W / m·K) 4.8±0.9 Without a Thermal Conductive Layer, Heat Diffuses in a Single Direction Infrared Reflectivity (%) 63.5±3.2 Without an h-BN Reflective Layer, Radiation Heat Dissipation is Severe Flexural Strength (cN / dtex) 3.0±0.5 Stress Concentration in the Single-Cavity Structure Prone to Fracture Comparative analysis: The single-chamber structure (without sub-chamber design) leads to a significant enhancement of air convection (the thermal resistance is only 0.26 ± 0.05 clo), and the absence of a functional layer results in a much lower thermal conductivity (4.8 ± 0.9 W / m·K) and infrared reflectivity (63.5%) compared to Example 1. The advantages of the present invention are reflected in the multi-chamber plum blossom petal structure, which suppresses air flow by dividing the cavity, and the thermal resistance is increased by 100% (Example 1: 0.52 clo). It is also reflected in the collaborative design of the functional layer, where the thermal conduction layer (directionally arranged GQDs) and the infrared reflection layer (oriented h-BN) significantly enhance the axial thermal conduction (14.9 W / m·K) and infrared reflectivity (92.1%).

[0066] Comparative Example 2: Commercially available down fabric Materials: 90% white duck down (fill power 650 FP), 10% nylon anti-feather leakage fabric (grammage 130 g / ㎡).

[0067] Others: Without active thermal management function (only relying on the static heat insulation of down).

[0068] Test results of Comparative Example 2: Test Item Data Data of Example 1 (Comparison) Analysis of the Reasons for the Differences Thermal Resistance Value (clo) 0.65±0.08 0.52±0.06 Down has Excellent Static Air Insulation but Poor Moisture Permeability (Moisture Permeation of the Example is 85% Higher) Thermal Conductivity (W / m·K) 0.023±0.005 14.9 ± 1.3 (Axial) Down has Low Thermal Conductivity but No Directionality, and the Example Can Achieve Axial Heat Conduction / Radial Heat Insulation Infrared Reflectivity (%) 72.3 ± 2.8 (8 - 14 μm) 92.1±1.8 Down Relies on Natural Protein Reflection, and the Example Improves the Reflectivity through h-BN Orientation Flexural Strength (cN / dtex) 1.2±0.3 4.3±0.7 Down has No Continuous Fiber Support, and the Core-Sheath Structure of the Example has Strong Flexural Resistance Moisture Permeation (g / m²·h) 280±35 518±45 The Multi-Cavity Structure of the Example Facilitates the Directional Discharge of Moisture Phase Change Enthalpy (J / g) 0 (Without PCMs) 85 ± 5 (Dynamic Temperature Regulation Layer) Down has No Temperature Adaptive Ability Comparative analysis: Down relies on static air heat insulation (thermal resistance 0.65 ± 0.08 clo), but the moisture permeability (280 g / m²·h) and anti-bending strength (1.2 cN / dtex) are insufficient, and there is no dynamic temperature regulation ability (phase change enthalpy 0 J / g).

[0069] The advantages of the present invention are reflected in the dynamic thermal management: the axial thermal conduction (14.9 W / m·K) realizes the directional guidance of heat and avoids local overheating. It is also reflected in the dynamic temperature regulation layer (phase change enthalpy 85 J / g) that improves the temperature adaptability. The balance between moisture permeability and strength. The multi-chamber structure promotes the discharge of moisture (moisture permeability 518 g / m²·h, an increase of 85%), and the core-sheath continuous fiber design has an anti-bending strength of 4.3 cN / dtex (down is only 1.2 cN / dtex).

[0070] Comparative Example 3 Core layer: The same as Example 1 (five-chamber plum blossom petal structure).

[0071] Thermal conduction layer: The mass ratio of GQDs / TPU is 1:100, but there is no magnetic field orientation process (GQDs are disorderly dispersed).

[0072] Infrared reflection layer: The content of h-BN is 15%, and there is no LCP shear orientation (the lamellae are randomly distributed).

[0073] Test results of Comparative Example 3: Test Item Data (Including Fluctuations) Cause Analysis Thermal Resistance Value (clo) 0.48±0.07 Disordered GQDs Weaken the Axial Heat Conduction Ability Thermal Conductivity (W / m·K) 7.1±1.3 Disordered Arrangement Leads to an Increase in Phonon Scattering Infrared Reflectivity (%) 89.2±2.7 Disordered Distribution of h-BN Reduces the Reflection Efficiency Flexural Strength (cN / dtex) 4.5±0.7 Close to Example 1 (Same Structure) Comparative analysis: When the magnetic field and LCP orientation process are not adopted, the disordered dispersion of GQDs results in the axial thermal conductivity (7.1 ± 1.3 W / m·K) being only 47% of that in Example 1, and the disordered distribution of h-BN reduces the infrared reflectivity to 89.2%. The advantages of the present invention are reflected in the optimization of the orientation process. The magnetic field induces the oriented arrangement of GQDs, and the axial heat conduction is increased by 110% (Example 1: 14.9 W / m·K). The LCP shear orientation makes the h-BN lamellae arranged in parallel, and the reflectivity is increased by 3.2% (Example 1: 92.1%). The structural stability is retained: the bending resistance strength (4.5 cN / dtex) is close to that in Example 1 (4.3 cN / dtex), proving that the orientation process does not affect the mechanical properties.

[0074] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention so as to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A hollow thermal insulation yarn fabric, characterized in that, The fabric is woven from hollow fibers in an interlaced lattice structure, and the interlaced lattice structure is formed by the warp and weft yarns being intertwined in a spiral winding manner. Micro air chambers are formed at the intersection points of the warp and weft yarns. The hollow fiber includes a core layer and a sheath layer: The core layer is a plum blossom petal-shaped multi-cavity structure formed by ultra-high molecular weight polyethylene, and the cavities are separated by radial connecting bridges. The sheath layer is sequentially a heat conduction enhancement layer, an infrared reflection layer, and a dynamic temperature regulation layer from the inside to the outside.

2. The hollow thermal yarn fabric according to claim 1, wherein The heat conduction enhancement layer is a graphene quantum dot grafted thermoplastic polyurethane composite layer, and the graphene quantum dots are arranged in the axial direction of the fiber. The infrared reflection layer is a blend layer of liquid crystal polymer and hydrophobic modified boron nitride, and the boron nitride is distributed in a sheet-like shape parallel to the fiber surface. The dynamic temperature regulation layer contains a thermally induced shape memory polymer with phase change microcapsules, and the wall material of the microcapsules is nano-silica coated with polydopamine. The graphene quantum dots in the heat conduction enhancement layer and the boron nitride sheets in the infrared reflection layer form a continuous heat conduction path, and the phase change microcapsules in the dynamic temperature regulation layer and the thermally induced shape memory polymer act synergistically to achieve a dynamic balance of heat absorption-storage-release.

3. The hollow thermal yarn fabric according to claim 1, wherein The inner wall of the cavity of the plum blossom petal-shaped multi-cavity structure is loaded with a temperature-sensitive polymer brush, and the polymer brush undergoes a conformational change in the temperature range of 25-35 °C to regulate the effective heat conduction area of the cavity.

4. The hollow thermal yarn fabric according to claim 1, wherein, The denier of the single filament of the hollow fiber is adapted to the plum blossom petal-shaped multi-cavity structure, so that the fiber can maintain the integrity of the cavity while meeting the spinnability. The wall thickness of the fiber is configured to be 10%-15% of the single filament diameter to ensure that the anti-bending strength is ≥4.5 cN / dtex.

5. The hollow thermal yarn fabric according to claim 2, wherein, The nano-silica is subjected to two-step modification treatment. First, amino active sites are introduced through a silane coupling agent, and then it reacts with a perfluoro silane to form a super-hydrophobic surface. The water contact angle after modification is ≥150°, and the surface energy is ≤20 mN / m.

6. The hollow thermal yarn fabric according to claim 1, wherein In the infrared reflection layer, the hydrophobic modified boron nitride forms a covalent bonding interface with the liquid crystal polymer through a silane coupling agent, and a fluorine-containing flame retardant is grafted on the surface of the boron nitride to form a hydrophobic-flame retardant bifunctional nanosheet.

7. The hollow thermal yarn fabric according to claim 1, characterized in that The warp and weft yarns of the interlaced lattice structure are intertwined at an angle of 45-60°, forming a gradient pore size distribution, where the pores with a pore size of 50-100 μm account for ≥70%. When the gram weight is 80-120 g / ㎡, the air permeability is ≥500 mm / s and the thermal resistance is ≥0.5 clo.

8. The hollow thermal yarn fabric according to claim 1, characterized in that, A polyurethane-based anti-down leakage layer is laminated on the back of the fabric. The thickness of the anti-down leakage layer is 5-10 μm, and the coverage area ratio is ≤15%.

9. The hollow thermal yarn fabric according to claim 2, characterized in that, The sheath layer also contains graphene sheets with a mass ratio of 0.5%-3%. The lateral size of the graphene sheets is 1-5 μm, the thickness is ≤5 nm, and they are arranged in a direction parallel to each other in the TPU matrix. The mass ratio of the graphene sheets to the nano-silica is 1:(2-5), and the angle between the long axis direction of the graphene sheets and the fiber axis is ≤15°.

10. The hollow thermal yarn fabric according to claim 2, wherein, Far-infrared ceramic powder is also dispersed in the sheath layer. The ceramic powder is a composite of magnesium germanate and titanium dioxide, with a particle size of 0.1 - 1 μm, a mass ratio of 2 - 8%, a far-infrared emissivity ≥ 0.

88. The surface of the far-infrared ceramic powder is coated with a nano-silica layer, and the coating thickness is 5% - 10% of the ceramic particle size.

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