Heat and moisture swelling yarn for heat management and production method of fabric of heat and moisture swelling yarn

Abstract

The invention discloses a heat and moisture swelling yarn for heat management and a production method of a fabric of the heat and moisture swelling yarn, and belongs to the field of functional textile materials. The gradually-changed section shrinkage polyester slub yarns are used as core yarns, acrylic staple fibers are used as outer cladding materials, and the yarns are spun through air-jet vortex. After the fabric is excited by heat and moisture, the core yarn is axially shrunk and radially expanded, and the acrylic fibers on the outer layer are synchronously and physically shrunk. Bidirectional synergistic shrinkage of the inner-layer fiber and the outer-layer fiber generates strong centripetal extrusion force, a high-density fit locking area is constructed, and the tail ends of the fibers which are prone to pilling are firmly and internally buckled in a yarn framework. Compared with the prior art, hairiness slippage is effectively blocked from the physical structure, the anti-pilling performance of the fabric is remarkably improved, meanwhile, gaps of the fabric are reduced, a static air layer is fully reserved, synergistic interaction of excellent warm keeping performance and anti-pilling performance is achieved, the technology compatibility is excellent, and the fabric is very suitable for large-scale mass production.

Description

Technical Field

[0001] This invention relates to the field of functional textile materials technology, and in particular to a method for producing a heat- and moisture-expanding yarn and its fabric for thermal management. Background Technology

[0002] Acrylic staple fiber, due to its superior morphology similar to natural wool, high loft, and excellent thermal insulation, is often chosen as the preferred outer layer fiber material for thermal management textiles. However, during weaving and wear, acrylic fibers are subject to friction, and the ends of these short fibers easily slip and pull out of the yarn. Furthermore, the released fibers have a certain strength and are not easily broken or shed, leading to extremely serious pilling problems in acrylic fabrics. Currently, to improve the warmth retention or anti-pilling properties of acrylic fibers, the industry mainly uses two methods: one is chemical modification (such as increasing micropores on the fiber surface and using anti-pilling resin coatings for surface bonding and curing); the other is traditional high-count, high-density physical spinning technology (such as increasing yarn twist and using compact spinning technology to forcibly compress the fibers into the yarn). This conventional approach falls into an irreconcilable physical contradiction: to achieve good warmth retention, the yarn must maintain a still air layer, but this will exacerbate the slippage and pilling of fuzz; to resist pilling, the yarn must be twisted and compacted or chemically hardened, which will make the fabric stiff, cause a sharp drop in porosity, and completely lose its excellent warmth retention.

[0003] To address the aforementioned challenges, the industry has undertaken numerous technological explorations. The first category involves existing publicly available literature on anti-pilling modification of acrylic staple fibers through blending. This literature proposes suppressing pilling through hot-melt bonding or chemical cross-linking. However, these methods suffer from drawbacks: they cause severe yarn hardening and a stiffer feel, severely damaging the original softness and three-dimensional fluffy warmth-retaining properties of acrylic. Patent CN121204846A discloses a method and apparatus for preparing gradient segmented shrinkage polyester slub yarn. It achieves programmed control of the shrinkage rate of different segments of polyester filament through a hot roller process. However, its drawback is that this technology is limited to the morphological processing of the pure acrylic filament itself and completely fails to address how to apply this structure to composite spinning to solve the problem of coating and stabilizing the easily pilling outer short fibers. The article "Research and Development of Composite Slub Yarn by Air Jet Vortex Spinning" (Tang Longshi et al.), published in the journal "Cotton Textile Technology", explored the process of preparing composite yarn using vortex spinning with slub filaments as the core yarn and short fibers as the covering layer. However, its shortcomings are that the research only explored the influence of spinning machine mechanical parameters (such as air pressure and tension) on the appearance of yarn evenness, and did not think of the micro-mechanism of using the shrinkage and expansion variables of the core yarn after exposure to moisture and heat to reverse and tighten the outer layer of hair that is prone to pilling.

[0004] In summary, existing technologies still have the following shortcomings and key issues that urgently need to be addressed: First, existing conventional composite core-spun yarns only achieve a simple mechanical layering of the core and sheath, and the outer short fibers fail to establish a deep physical bond with the core skeleton, resulting in the surface short fibers still easily slipping and pilling when the fabric is subjected to friction; Second, existing multi-component spinning technologies lack an active internal dynamic fastening mechanism, and cannot utilize the heat and humidity environment in subsequent processes to spontaneously stimulate strong bidirectional shrinkage and radial compression stress between the core yarn and the outer fibers, thus failing to lock the fiber ends at the physical source; Third, the industry urgently needs a new production process for heat and humidity swell yarns and their fabrics to achieve a perfect balance between functionality and durability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention aims to provide a method for producing thermally hygroscopic yarns and their fabrics for thermal management.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] A method for producing a heat- and moisture-swelling yarn and its fabric for thermal management is as follows:

[0008] Step 1: Select short textile fibers as the outer layer material, and process them sequentially through opening and cleaning, carding, and drawing processes to obtain a sliver;

[0009] Step 2: Use gradient segmented polyester slub yarn as the core yarn and introduce it into the front roller nip through the guide hook; at the same time, feed in the sliver prepared in step 1 and perform core-spun yarn by ring spinning or vortex spinning to obtain a heat-moisture swelling yarn for thermal management.

[0010] Preferably, the production method of the heat- and moisture-induced swelling yarn and its fabric for thermal management is as follows:

[0011] Step 1: Select short textile fibers as the outer layer material, and process them sequentially through opening and cleaning, carding, and drawing processes to obtain a finished sliver with a weight of 12-25g / 5 meters.

[0012] Step 2: Use gradient segmented polyester slub yarn as the core yarn and place it in the core yarn unwinding device of the air jet vortex spinning machine. Introduce it into the front roller nip through the guide hook. At the same time, feed the sliver prepared in step 1 into the drafting mechanism. The front roller will combine the drafted fiber sliver with the core yarn before it enters the vortex nozzle. Adjust the working parameters of the air jet vortex spinning machine to obtain the heat- and moisture-expanding yarn for thermal management.

[0013] The textile staple fiber is at least one of acrylic staple fiber, cotton fiber, polyester staple fiber, and viscose staple fiber.

[0014] Preferably, the textile staple fiber is acrylic staple fiber.

[0015] The operating parameters for the vortex spinning are as follows: controlling the air pressure at the spinning nozzle to be 0.4-0.5 MPa, the core yarn unwinding tension to be 1.8-3.2 cN, and the spinning speed to be set to 300-380 m / min.

[0016] Preferably, the operating parameters of the vortex spinning are as follows: controlling the air pressure of the spinning nozzle to be 0.42 MPa, the core yarn unwinding tension to be 2.5 cN, and the spinning speed to be set to 340 m / min.

[0017] The mass ratio of the core yarn to the outer short fiber in the heat- and moisture-expanding yarn is 0.8-1.2:0.8-1.5.

[0018] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is as follows:

[0019] First, the heat- and moisture-expanding yarn is processed through warping and warping processes before being woven on a loom. After weaving, the fabric undergoes a heat- and moisture-expanding treatment process. This process involves passing the fabric in a flat state through a steam box for 80-150 seconds at a temperature of 78-108℃, relative humidity of 80-99%, and a running speed of 20-30m / min, followed by drying at 80-100℃ for 60-120 seconds to obtain the heat- and moisture-expanding yarn fabric.

[0020] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management can also be the following method:

[0021] First, the heat- and moisture-expanding yarn is processed through warping and warping processes before being woven on a loom. After weaving, the fabric undergoes a heat- and moisture-expanding treatment process. This process involves passing the fabric in a flat state through a steam box and continuously processing it in three zones: Zone I: temperature 78-82℃, relative humidity 88-92%, running speed 23-28m / min, duration 30-50 seconds; Zone II: temperature 90-94℃, relative humidity 95-99%, running speed 20-25m / min, duration 40-60 seconds; Zone III: temperature 100-108℃, relative humidity 80-87%, running speed 25-30m / min, duration 20-40 seconds. After exiting the steam box, the fabric immediately enters a drying unit and is dried at 80-100℃ for 60-120 seconds to obtain the heat- and moisture-expanding yarn fabric.

[0022] The weaving adopts a 1×1 plain weave structure and is carried out on an air-jet loom, with the warp density set at 150-200 ends / 10cm and the weft density set at 140-180 ends / 10cm. The machine tension is controlled at 150-200N and the machine speed is 400-600r / min.

[0023] While acrylic staple fiber possesses excellent bulk and warmth retention properties, its smooth surface and low fiber rigidity make it prone to slippage and entanglement at the fiber ends when the fabric is subjected to friction, leading to severe pilling and fuzzing. Traditional methods of increasing twist or chemically binding completely negate its warmth retention. To address this contradiction, this invention proposes a novel composite yarn design that utilizes the bidirectional synergistic shrinkage of inner and outer fiber layers to create a physical interlocking effect.

[0024] One of the core foundations of this approach is the use of independently developed gradient segmented polyester slub yarn as the core yarn. During the manufacturing process, this core yarn undergoes segmented stretching to create an alternating pattern of slub thickness, and these segments of different dimensions store enormous potential for thermal and moisture shrinkage.

[0025] In the jet-jet vortex spinning composite coating process, this invention specifically selects acrylic staple fiber, which also has good heat shrinkage properties, as the outer coating material, and evenly wraps it around the polyester slub yarn core. This material combination allows the spun initial-state warm yarn to simultaneously contain the dual thermoplastic deformation potential of the core yarn and the outer coating.

[0026] When the final fabric undergoes a heat and moisture process, a synergistic effect occurs. The gradient segmented polyester slub filaments exhibit strong axial shrinkage and radial expansion, while the outer acrylic fibers also undergo synchronous, opposing shrinkage. The centripetal compression generated by both creates a high-density, tightly fitted locking zone, firmly securing the acrylic fiber ends within the structural framework. This not only prevents pilling and slippage at the source and reduces fabric porosity, but also maintains a high static air retention rate through microscopic deformation, achieving a perfect balance between warmth and anti-pilling properties.

[0027] Compared with the prior art, the present invention has the following beneficial technical effects:

[0028] 1) Under the excitation of heat and moisture, the polyester core yarn and the outer acrylic yarn undergo bidirectional synergistic shrinkage, generating a strong centripetal extrusion force to lock the hairs in the yarn skeleton, solving the problem of pilling from the physical source, while retaining a static air layer to ensure ultimate warmth.

[0029] 2) The high-density fit physical locking zone formed by the synchronous strong shrinkage of the inner and outer layers of this invention enables the yarn to achieve the best three-dimensional bulkiness and compactness balance. The structure is irreversible and can still maintain excellent surface anti-pilling strength after washing and repeated strong friction in daily life.

[0030] 3) This invention can trigger physical self-tightening reconstruction simply by using conventional jet vortex spinning composite combined with existing heat and moisture setting processes. It avoids fabric stiffness defects without any chemical adhesives, has excellent process compatibility, and is suitable for low-cost mass production. Detailed Implementation

[0031] Some material parameters and their sources:

[0032] Polyester staple fiber, fiber fineness: 1.2D-1.5D, fiber length: 30mm-38mm, cross-sectional shape: round, boiling water shrinkage rate ≤3%.

[0033] Acrylic staple fiber, with a fiber fineness of 1.5D and a length of 38mm.

[0034] Cotton fiber: Commercially available high-quality combed long-staple cotton, with a main body length of 35mm-38mm, micronaire value of 3.8-4.2, and short fiber content ≤5%.

[0035] Viscose staple fiber: Commercially available regular spinning grade cotton-type viscose staple fiber with a fiber fineness of 1.5D, a length of 38mm, and a dry breaking strength ≥2.40cN / dtex.

[0036] Polyester filament: Commercially available conventional fully drawn polyester filament (FDY) with a constant linear density of 100D / 36F, no slub shape, and a hot water shrinkage rate of ≤3% at 80℃ / 10min.

[0037] The gradient segmented polyester slub yarn used in this invention is prepared according to Example 2 of the invention patent application No. CN202511440472.3 published by the State Intellectual Property Office (application date: October 10, 2025). The core technical parameters adopted are: the linear speed of the first hot roller is programmed to switch in four segments; the linear speed of the second hot roller is kept constant at V2=2800m / min; the total stretch ratio E=4.50 remains unchanged; and the temperature of the first hot roller is set to a constant value of 78℃. This results in four segments along the axial direction of the yarn: slub thick segment 1, slub thin segment 2, slub thick segment 3, and slub segment 4. Section 4; The meanings of the symbols in the table are as follows: V1 (m / min) represents the linear speed of the first hot roller; E2=V2 / V1 is the main stretching ratio between the first and second hot rollers, which directly determines the degree of molecular orientation; linear density (D) refers to the linear density of the entire yarn at room temperature; 10min, 80℃ shrinkage rate (%) refers to the percentage of shrinkage of each segment relative to the initial length after the standard is treated in 80℃ water for 10 minutes, reflecting the difference in the tightness of the microstructure; the segment length (cm) is determined by the holding time of each speed segment set by the programmable controller, which is used to precisely control the size of the bamboo joint shape.

[0038] The specific parameters of the obtained gradient segmented polyester slub yarn are shown in Table 1:

[0039] Table 1

[0040] Segment positioning [V1 (m / min)] [E2 = V2 / V1] Linear density (D) Shrinkage at 10 min, 80°C (%) Segment length (cm) Bamboo thick segment 1 1800 1.56 100 23.0 32.0 Bamboo thin segment 2 1400 2.0 100 8.7 106.5 Bamboo thick segment 3 1600 1.75 100 15.3 25.8 Bamboo thin segment 4 1250 2.24 100 5.2 124.7

[0041] In the embodiments and comparative examples of this invention, all raw materials are commercially available products.

[0042] Example 1

[0043] A method for producing heat- and moisture-expanding yarn for thermal management is as follows:

[0044] Step 1: Select acrylic staple fiber as the outer layer material, feed the acrylic staple fiber into the traditional spinning pre-process equipment, and successively pass through the opening and cleaning, carding and drawing processes to obtain acrylic sliver with straight fiber arrangement and uniform evenness, with a weight of 16g / 5m.

[0045] Step 2: Using gradient segmented polyester slub yarn as the core yarn, place it in the core yarn unwinding device of the air-jet vortex spinning machine and guide it into the front roller nip through the guide hook; at the same time, feed the acrylic sliver prepared in Step 1 into the drafting mechanism, and the front roller will combine the drafted fiber sliver with the core yarn before entering the vortex nozzle. Adjust the working parameters of the air-jet vortex spinning machine, control the air pressure of the spinning nozzle to 0.48MPa, the core yarn unwinding tension to 3.2cN, the spinning speed to 380m / min, and the mass ratio of core yarn to outer short fiber to 1:1 to obtain a heat- and moisture-expanding yarn for thermal management.

[0046] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is as follows:

[0047] First, the heat- and moisture-expanding yarn is processed through warping and warping processes before being woven on a loom. The weaving adopts a 1×1 plain weave structure and is carried out on an air-jet loom, with the warp density set at 180 ends / 10cm and the weft density set at 160 ends / 10cm. The loom tension is controlled at 180N and the machine speed is 520r / min. After weaving, the fabric undergoes a heat- and moisture-expanding treatment process. The heat- and moisture-expanding treatment process involves passing the fabric in a flat state through a steam box for 120 seconds at a temperature of 85℃, a relative humidity of 95%, and a running speed of 25m / min, followed by drying at 100℃ for 90 seconds to obtain the fabric of the heat- and moisture-expanding yarn.

[0048] Example 2

[0049] A method for producing a heat- and moisture-expanding yarn for thermal management is basically the same as in Example 1, except that the acrylic staple fiber is replaced with an equal amount of cotton fiber.

[0050] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is the same as in Example 1.

[0051] Example 3

[0052] A method for producing heat- and moisture-expanding yarn for thermal management is basically the same as that in Example 1, except that the acrylic staple fiber is replaced with an equal amount of polyester staple fiber.

[0053] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is the same as in Example 1.

[0054] Example 4

[0055] A method for producing a heat- and moisture-expanding yarn for thermal management is basically the same as in Example 1, except that the acrylic staple fiber is replaced with an equal amount of viscose staple fiber.

[0056] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is the same as in Example 1.

[0057] Example 5

[0058] A method for producing heat- and moisture-expanding yarn for thermal management is as follows:

[0059] Step 1: Select acrylic staple fiber as the outer layer material, feed the acrylic staple fiber into the traditional spinning pre-process equipment, and successively pass through the opening and cleaning, carding and drawing processes to obtain acrylic sliver with straight fiber arrangement and uniform evenness, with a weight of 16g / 5m.

[0060] Step 3: Using gradient segmented polyester slub yarn as the core yarn, place it in the core yarn unwinding device of the air-jet vortex spinning machine and guide it into the front roller nip through the guide hook; at the same time, feed the acrylic sliver prepared in step 2 into the drafting mechanism, and the front roller will combine the drafted fiber sliver with the core yarn before entering the vortex nozzle. Adjust the working parameters of the air-jet vortex spinning machine, control the air pressure of the spinning nozzle to 0.42MPa, the core yarn unwinding tension to 2.5cN, the spinning speed to 340m / min, and the mass ratio of core yarn to outer short fiber to 1:1 to obtain a heat- and moisture-expanding yarn for thermal management.

[0061] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is the same as in Example 1.

[0062] Example 6

[0063] A method for producing heat- and moisture-expanding yarn for thermal management is as follows:

[0064] Step 1: Select acrylic staple fiber as the outer layer material, feed the acrylic staple fiber into the traditional spinning pre-process equipment, and successively pass through the opening and cleaning, carding and drawing processes to obtain acrylic sliver with straight fiber arrangement and uniform evenness, with a weight of 16g / 5m.

[0065] Step 3: Using gradient segmented polyester slub yarn as the core yarn, place it in the core yarn unwinding device of the air-jet vortex spinning machine and guide it into the front roller nip through the guide hook; at the same time, feed the acrylic sliver prepared in step 2 into the drafting mechanism, and the front roller will combine the drafted fiber sliver with the core yarn before entering the vortex nozzle. Adjust the working parameters of the air-jet vortex spinning machine, control the air pressure of the spinning nozzle to 0.4MPa, the core yarn unwinding tension to 1.8cN, the spinning speed to 320m / min, and the mass ratio of core yarn to outer short fiber to 1:1 to obtain a heat- and moisture-expanding yarn for thermal management.

[0066] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is the same as in Example 1.

[0067] Example 7

[0068] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is as follows:

[0069] First, the heat- and moisture-expanding yarn is processed through warping and warping processes before being woven on a loom. The weaving uses a 1×1 plain weave structure on an air-jet loom, with a warp density of 180 ends / 10cm and a weft density of 160 ends / 10cm. The loom tension is controlled at 180N, and the machine speed is 520r / min. After weaving, the fabric undergoes a heat-and-moisture treatment process. This process involves passing the fabric flat through a steam chamber and continuously treating it in three zones: Zone I: temperature 80℃, relative humidity 90%, running speed 25m / min, duration 40 seconds; Zone II: temperature 92℃, relative humidity 98%, running speed 22m / min, duration 50 seconds; Zone III: temperature 105℃, relative humidity 85%, running speed 28m / min, duration 30 seconds. Immediately after exiting the chamber, the fabric enters a drying unit and is dried at 100℃ for 90 seconds to obtain the heat- and moisture-expanding yarn fabric.

[0070] The production method of the heat-moisture swelling yarn used for thermal management is the same as that in Example 5.

[0071] Comparative Example 1

[0072] A method for producing heat- and moisture-expanding yarn for thermal management is basically the same as that in Example 1, except that the gradient-shrunk polyester slub yarn is replaced with ordinary commercially available polyester filament of equal linear density.

[0073] The method for producing the fabric of the heat-moisture swelling yarn used for thermal management is the same as in Example 1.

[0074] Test Example 1

[0075] Fabric thermal resistance test:

[0076] The test method refers to the test method in GB / T11048-2018 "Determination of thermal and moisture resistance of textiles under steady-state conditions for physiological comfort (evaporative hot plate method)":

[0077] The equipment uses a fabric thermal resistance tester (compliant with ISO 11092 standard) and is equipped with a constant temperature and humidity chamber; sample area: 0.05m² 2 (Circular), Hot plate temperature T h 35±0.1℃, cold plate temperature T c Temperature: 20±0.1℃; Environment: 20±0.5℃, 65±2%RH; All samples were conditioned for 24 hours before testing.

[0078] Place the sample flat between the hot and cold plates, avoiding wrinkles; start the equipment and record the heat flux density q (W / m³) after the heat flow stabilizes (≥10 min). 2 );

[0079] Calculate thermal resistance R=(T) h -T c ) / q(m 2 (·K / W)

[0080] Converted to Clo value: Clo = R / 0.155;

[0081] Five parallel samples were used in each group, and the average value was taken. The test results are shown in Table 2.

[0082] Table 2

[0083] Experimental protocol CLO value Example 1 0.412 Example 2 0.365 Example 3 0.348 Example 4 0.355 Example 5 0.446 Example 6 0.431 Example 7 0.485 Comparative example 1 0.315

[0084] Test Example 2

[0085] Fabric pilling performance test:

[0086] The test was conducted in accordance with the national standard GB / T4802.2-2008 "Textiles - Determination of pilling properties of fabrics - Part 2: Modified Martindale method".

[0087] Equipment and parameters: Martindale abrasion and pilling tester was used; the diameter of the test sample was 140 mm, and the total load was 415 g.

[0088] Test environment: temperature 20±2℃, relative humidity 65±5%, all samples were conditioned for 24 hours before testing;

[0089] Friction cycles: Set the friction cycles to 7000 revolutions;

[0090] Rating method: After testing, the samples are placed in a standard rating darkroom and compared with standard sample photos for rating. The rating is divided into 1-5 levels, with level 5 being the best (no pilling) and level 1 being the worst (severe pilling). Half-level ratings are also possible. Four parallel seam samples are tested in each group, and the average result is taken. The relevant test data are summarized in Table 3.

[0091] Table 3

[0092] Experimental protocol Pilling rating (class) Example 1 3.5 Example 2 3.0 Example 3 2.5 Example 4 3.0 Example 5 4.0 Example 6 3.5 Example 7 4.5 Comparative example 1 2.0

[0093] Compared to Comparative Example 1, which exhibited severe pilling and fuzzing, Example 1 demonstrated significantly improved warmth retention and anti-pilling properties. This is primarily because Comparative Example 1 used ordinary polyester filaments, whose core yarn lacked strong shrinkage capacity under heat and moisture stimulation. The outer acrylic staple fibers were in a relatively loose mechanically encapsulated state, making it easy for free fibers to slip off the surface and entangle into balls after friction. In contrast, Example 1 used gradient segmented polyester slub yarn as the core yarn. During heat and moisture treatment, the core yarn underwent strong axial shrinkage and radial expansion. Combined with the inherent heat shrinkage characteristics of acrylic fibers, the two produced a centripetal, bidirectional synergistic shrinkage and tightening. This powerful radial compression not only reduced the fabric's porosity but also firmly locked the originally easily pilling acrylic staple fiber ends within the skeleton, fundamentally reducing the probability of fiber slippage and entanglement pilling.

[0094] In the comparison of different conventional staple fibers, Example 1 performed best. Although cotton (Example 2), polyester (Example 3), and viscose (Example 4) can all be wrapped by the core yarn, their thermoplasticity and shrinkage deformation under hot and humid conditions are minimal. When the core yarn shrinks drastically, cotton, conventional polyester, and viscose cannot undergo synchronous physical shrinkage, resulting in wrinkling or loose gaps in the outer layer structure, limited increase in thermal resistance, and easy exposure of fibers. Acrylic staple fiber, on the other hand, is a fiber with good thermoplasticity and also shrinks to a certain extent when exposed to humid heat. In Example 1, the synergistic shrinkage of the inner and outer layers forms a high-density, tightly fitted area, which reduces the size of micropores and results in an extremely high static air retention rate, thus exhibiting an absolute advantage in warmth retention and surface anti-pilling and anti-friction properties.

[0095] The technical effect of Example 5 is superior to that of Examples 1 and 6, and its mechanism lies in the precise adaptation of air-jet vortex spinning parameters. In Example 1, the air pressure was too high (0.48 MPa) and the tension was too high (3.2 cN), resulting in excessively tight wrapping, which restricted the free deformation space for core yarn expansion and acrylic shrinkage during subsequent heat and moisture treatment, resulting in the porosity not reaching its maximum. In Example 6, the air pressure was too low (0.4 MPa) and the tension was too low (1.8 cN), resulting in insufficient initial twisting force of the wrapping airflow on the acrylic, and a loose yarn structure. Although sufficient space for thermal expansion was provided, the initial fiber-fixing ability was poor, and the fibers were more easily pulled out prematurely during friction. Example 5 (air pressure 0.42 MPa, tension 2.5 cN) achieved a perfect balance between stable wrapping and reserved expansion space, so that the yarn after heat and moisture activation was in the optimal three-dimensional expansion and locking state.

[0096] Example 7 outperforms Example 5, primarily due to its three-stage gradient heat and humidity activation mechanism (zones I, II, and III). Example 5, being a single-stage constant-temperature instantaneous treatment, experiences a burst release of shrinkage stress in the yarn surface and core, easily leading to uneven deformation or even microstructural breakage in some yarn sections. Example 7, however, utilizes a gradient increase in temperature and humidity from low to high, causing the outer acrylic fibers to initially swell and soften in a mild environment. Subsequently, the inner core yarn gradually releases its internal shrinkage stress and undergoes orderly reconstruction upon heating. This gradual expansion process maximizes the network friction generated by the compression between fibers, perfectly forming an irreversible heat-setting mechanical anchoring network, giving the fabric better thermal insulation, heat resistance, and anti-pilling properties.

Claims

1. A method for producing heat- and moisture-expanding yarn for thermal management, characterized in that, The method is as follows: Step 1: Select short textile fibers as the outer layer material, and process them sequentially through opening and cleaning, carding, and drawing processes to obtain a sliver; Step 2: Use gradient segmented polyester slub yarn as the core yarn and introduce it into the front roller nip through the guide hook; at the same time, feed in the sliver prepared in step 1 and perform core-spun yarn by ring spinning or vortex spinning to obtain a heat-moisture swelling yarn for thermal management.

2. The method for producing heat- and moisture-expanding yarn for thermal management as described in claim 1, characterized in that, The method is as follows: Step 1: Select short textile fibers as the outer layer material, and process them sequentially through opening and cleaning, carding, and drawing processes to obtain a finished sliver with a weight of 12-25g / 5 meters. Step 2: Use gradient segmented polyester slub yarn as the core yarn and place it in the core yarn unwinding device of the air jet vortex spinning machine. Introduce it into the front roller nip through the guide hook. At the same time, feed the sliver prepared in step 1 into the drafting mechanism. The front roller will combine the drafted fiber sliver with the core yarn before it enters the vortex nozzle. Adjust the working parameters of the air jet vortex spinning machine to obtain the heat- and moisture-expanding yarn for thermal management.

3. The method for producing heat- and moisture-expanding yarn for thermal management as described in claim 1 or 2, characterized in that, The textile staple fiber is at least one of acrylic staple fiber, cotton fiber, polyester staple fiber, and viscose staple fiber.

4. The method for producing heat- and moisture-expanding yarn for thermal management as described in claim 1 or 2, characterized in that, The textile staple fiber is acrylic staple fiber.

5. The method for producing heat- and moisture-expanding yarn for thermal management as described in claim 1 or 2, characterized in that, The operating parameters for the vortex spinning are as follows: controlling the air pressure at the spinning nozzle to be 0.4-0.5 MPa, the core yarn unwinding tension to be 1.8-3.2 cN, and the spinning speed to be set to 300-380 m / min.

6. The method for producing heat- and moisture-expanding yarn for thermal management as described in claim 1 or 2, characterized in that, The operating parameters for the vortex spinning are as follows: the air pressure at the spinning nozzle is controlled at 0.42 MPa, the core yarn unwinding tension is 2.5 cN, and the spinning speed is set at 340 m / min.

7. The method for producing heat- and moisture-swelling yarn for thermal management as described in claim 1 or 2, characterized in that, The mass ratio of the core yarn to the outer short fiber in the heat- and moisture-expanding yarn is 0.8-1.2:0.8-1.

5.

8. A method for producing fabric from thermally swellable yarn for thermal management as described in any one of claims 1-7, characterized in that, The method is as follows: First, the heat- and moisture-expanding yarn is processed through warping and warping processes before being woven on a loom. After weaving, the fabric undergoes a heat- and moisture-expanding treatment process. This process involves passing the fabric in a flat state through a steam box for 80-150 seconds at a temperature of 78-108℃, relative humidity of 80-99%, and a running speed of 20-30m / min, followed by drying at 80-100℃ for 60-120 seconds to obtain the heat- and moisture-expanding yarn fabric.

9. The method as described in claim 8, characterized in that, The production method of the heat-moisture swelling yarn fabric for thermal management can also be as follows: First, the heat-moisture swelling yarn is processed by the warping and winding processes and then woven on a machine; after weaving, the greige fabric undergoes a heat-moisture treatment process, which involves passing the greige fabric in a flat state through a steam box and continuously treating it in the following three zones: Zone I: temperature 78-82℃, relative humidity 88-92%, running speed 23-28m / min, duration 30-50 seconds; Zone II: temperature 90-94℃, relative humidity 95-99%, running speed 20-25m / min, duration 40-60 seconds; Zone III: temperature 100-108℃, relative humidity 80-87%, running speed 25-30m / min, duration 20-40 seconds; after exiting the steam box, it immediately enters a drying unit and is dried at 80-100℃ for 60-120 seconds to obtain the heat-moisture swelling yarn fabric.

10. The method as described in claim 8 or 9, characterized in that, The weaving adopts a 1×1 plain weave structure and is carried out on an air-jet loom, with the warp density set at 150-200 ends / 10cm and the weft density set at 140-180 ends / 10cm. The machine tension is controlled at 150-200N and the machine speed is 400-600r / min.