Moisture-absorbing and sweat-releasing warm fiber, and preparation method and application thereof

Abstract

The present application belongs to the technical field of textile materials, and relates to a moisture-absorbing, sweat-releasing and warm-keeping fiber as well as a preparation method and application thereof. The preparation method is to heat set the solid-shaped cross-section core yarn and the pile yarn after air elastic recovery, control the overfeed rate to make the core yarn straight and the pile yarn form excess length sections, and control the air supply pressure to make the pile yarn form pile tufts and intermittently gather into pile clusters. The fiber prepared by the method can be directly used as a filling body in the form of loose fibers or fluffs without cutting and weaving. The present application has the functions of moisture absorption, sweat release and high warm-keeping performance, and has stable structure and no pilling problem.

Description

Technical Field

[0001] This invention belongs to the field of textile materials technology, and relates to a moisture-wicking and heat-retaining fiber, its preparation method and application. Background Technology

[0002] Down, with its unique three-dimensional down cluster structure, has excellent loft and warmth retention properties and is widely used in the field of thermal insulation filling. However, natural down has the defects of being prone to leakage and feather loss, and it has poor moisture absorption. The moisture produced by the human body cannot be quickly discharged, which can easily lead to stuffy sweating. After absorbing moisture, the filling material is prone to caking, and the warmth retention performance is greatly reduced.

[0003] Down-like fibers are artificially synthesized biomimetic insulation filling materials that can replace natural down in various insulation products. They have the advantages of controllable cost, convenient processing, water resistance, and resistance to mildew and insects, making them the mainstream alternative product in the field of insulation filling materials.

[0004] Patent application CN118166553A discloses a method for preparing cold-resistant down-like modified polyester fiber. The method involves heating and melting polyimide fiber and polyester fiber chips to obtain a blend. This blend is then melt-extruded separately from ceramic fiber using a screw extruder. The two melts are combined and extruded through a spinneret. The resulting product undergoes winding, bundling, stretching, silicone finishing, relaxation heat setting, and cutting processes to obtain the cold-resistant down-like modified polyester fiber. This fiber possesses good bulk, compression resilience, and air content. The synergistic effect of the polyester fiber and polyimide fiber effectively enhances the fiber's warmth retention performance.

[0005] However, the fibers produced by the aforementioned patents still cannot achieve active moisture absorption and perspiration. Moisture easily accumulates in the filling layer, causing a stuffy feeling. Furthermore, they do not form a stable down-like three-dimensional fluffy structure and lack effective skeletal support. With long-term use, they are easily flattened and hardened, and their warmth retention performance cannot be maintained continuously, making it difficult to meet the needs of high-quality warmth retention.

[0006] Therefore, it is necessary to provide a moisture-wicking and heat-retaining fiber to solve the aforementioned problems of the existing technology. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art and to provide a moisture-wicking and heat-retaining fiber, its preparation method and application.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing a moisture-wicking and heat-insulating fiber involves first combining two continuous filaments, a core filament and a fleece filament, through air texturing to obtain a composite filament, and then heat-setting the composite filament to obtain the moisture-wicking and heat-insulating fiber.

[0010] In the process of air texturing and compounding, the overfeed rate of the core filament and the down filament is controlled so that the core filament is in a straight state and the down filament is in a non-straight state with an excess length relative to the core filament. At the same time, the air supply pressure is controlled so that under the action of airflow, the excess length of the down filament wraps around the surface of the core filament in an irregular loop shape, forming down clusters similar to natural down, and the down clusters intermittently gather along the core filament axis to form down tufts.

[0011] The core fiber is a solid, irregularly shaped fiber.

[0012] The reason why the phenomenon of "intermittent aggregation of down clusters along the core filament axis to form down tufts" occurs in this invention is as follows:

[0013] Based on the principles of Karman vortex street and nozzle hydrodynamics, compressed air does not flow smoothly as it passes through the nozzle throat and enters the deformation chamber. Instead, it generates periodic vortices with a certain frequency. When high-speed airflow impacts the fiber, the release of kinetic energy is fluctuating. The concentrated energy "instantaneous strong vortex zone" violently impacts the filaments for a short period, forcing a large number of overfed filaments to clump together to form dense loops. The "conversion zone" between the two sets of vortices has slightly weaker energy, resulting in a lower density of loops. This inherent physical periodicity of the airflow directly causes the filaments to form a series of "alternating dense and sparse" tufts on the core filament.

[0014] The feed rate of the filaments is much greater than the draw rate, and there is a dynamic overfeed reserve zone inside the nozzle. The filaments do not continuously and uniformly circle inside the nozzle, but undergo a microsecond-level "accumulation" process. Due to the micro-friction between the fibers and the nozzle wall, and between the fibers themselves, the filaments will experience a certain degree of "restriction and accumulation" within the nozzle cavity for a short period of time. When the amount of accumulated fibers reaches a certain level, they are forcefully pushed towards the core filament by the airflow pressure, resulting in an explosive entanglement. This repeated cycle from "accumulation" to "explosive entanglement" manifests as intermittently distributed "tufts" along the macroscopic filament axis.

[0015] In the traditional textile processing field, there is an existing technology that combines two or more continuous filaments through an air texturing nozzle, which is commonly referred to in the industry as air-textured yarn. However, the existing technology does not control the overfeed rate and air supply pressure like the present invention, so the structure of the air-textured yarn in the existing technology is significantly different from the moisture-wicking and heat-retaining fiber of the present invention.

[0016] The moisture-wicking and heat-insulating fiber of the present invention simulates the micromechanical structure of down: the core filament, as the supporting skeleton, can play the role of the feather shaft, bear the compressive load, and prevent the moisture-wicking and heat-insulating fiber from being flattened and hardened. At the same time, the core filament can also absorb and wick away moisture using its irregular cross-section; the down filaments form down tufts, which use their chaotic and fluffy ring structure to intercept a large amount of still air, thereby achieving high thermal resistance (heat retention).

[0017] The moisture-wicking and heat-retaining fiber of this invention is a continuous filament, which is equivalent to stringing millions of "down clusters" on a rope, thus solving the problem of feather leakage in traditional down products.

[0018] As a preferred technical solution:

[0019] The method for preparing a moisture-wicking and heat-retaining fiber as described above has a core filament with a cross-sectional shape of "+", Y, W or octagon, and the irregularity of the cross-sectional shape of the core filament is 15%-35%. Irregularity = (area of ​​the circumscribed circle of the irregular cross-section - actual area of ​​the irregular cross-section) × 100% / area of ​​the circumscribed circle of the irregular cross-section.

[0020] The irregular cross-section breaks away from the smooth surface of a conventional circular core filament. The smooth surface of a traditional circular core filament results in a small contact area with the fleece filaments, making it prone to slippage. In contrast, the irregularly shaped core filament has an uneven surface with grooves, significantly increasing the contact area and coefficient of friction between the fleece filaments and the core filaments. During air-textured lamination, the fluffy outer fleece filaments are compressed and "embedded" in these grooves, forming a meshing and locking mechanism similar to mechanical gears. This physical interlocking action locks the position of the fleece filaments, preventing them from sliding up and down or clumping apart during subsequent washing, stretching, and everyday wear.

[0021] To effectively prevent the filaments from sliding up and down or peeling and clumping, the irregularity of the cross-section needs to be controlled between 15% and 35%. If the irregularity is less than 15%, the grooves are too shallow and cannot form effective mechanical engagement; if the irregularity is greater than 35%, the spinning breakage rate of the core filament is high, and the sharp protrusions lead to a poor hand feel.

[0022] The preparation method of the moisture-wicking and heat-insulating fiber described above, wherein the polymer matrix of the core fiber is PET (polyethylene terephthalate), PTT (polypropylene terephthalate), or PBT (polybutylene terephthalate); the core fiber contains 0.5-3.0 wt% hydrophilic masterbatch, which can further enhance the moisture absorption performance.

[0023] The method for preparing a moisture-wicking and warm fiber as described above involves using a filament with a hollow structure. The filament has a cross-sectional shape that is circular hollow, C-shaped hollow, O-shaped porous hollow, or figure-eight hollow, with a hollowness of 15%-45%.

[0024] In the preparation method of the moisture-wicking and heat-insulating fiber described above, the polymer matrix of the fleece is PA6 (polyamide 6), PBT, PTT or PLA (polylactic acid).

[0025] The method for preparing a moisture-wicking and warm fiber as described above involves a heat-setting temperature of 100-190℃, a time of 30-80s, a tension of 0cN / dtex, and an overfeed rate of 3%-8%. Heat setting can stabilize the tuft structure and hollow morphology.

[0026] The method for preparing a moisture-wicking and heat-retaining fiber as described above has the following characteristics: the linear density of the core filament is 1.0-5.0 dtex, and the bus density is 30-150 dtex; the linear density of the pile filament is 0.5-3.0 dtex, and the bus density is 20-100 dtex; the ratio of the bus density of the core filament to the bus density of the pile filament is 1.2-2.8:1.

[0027] In the preparation method of the moisture-wicking and heat-retaining fiber described above, the overfeed rate of the pile filament is 1000%-4000%, and the overfeed rate of the core filament is 0%-5%. The overfeed rate of the pile filament is higher than that of the core filament, and the difference between the two is at least 1000%. This ensures that "the core filament is in a straight state, and the pile filament is in a non-straight state with a longer length relative to the core filament".

[0028] The method for preparing a moisture-wicking and heat-insulating fiber as described above uses an air supply pressure of 0.5-2.5 MPa.

[0029] If the air supply pressure is below 0.5 MPa, although the airflow is disturbed, the turbulent kinetic energy is too weak. The high-speed fed filaments themselves have tension and bending stiffness. At this time, the airflow can only cause the filaments to undergo slight "high-frequency vibration" in the nozzle, and the fibers will be blown apart, but it cannot overcome the bending internal stress of the filaments to form a closed structure. As a result, the filaments that come out are only fuzzy and do not coil, and cannot form tufts.

[0030] Only when the supply pressure reaches 0.5 MPa or higher can the airflow velocity exceed supersonic speed, forming a Mach disk and strong turbulent vortex at the nozzle exit. At this point, the lateral impact force exerted by the airflow on the filament is sufficient to overcome the bending stiffness of the filament, forcing the excess length of the filament to fold and wrap around itself at 180°, locking it onto the core filament.

[0031] If the air supply pressure exceeds 2.5MPa, not only will the air consumption increase dramatically and become extremely uneconomical, but the excessively strong high-frequency turbulence will also break the fine denier monofilaments (i.e., produce fuzz and broken ends), which will damage the continuity and strength stability of the moisture-wicking and heat-insulating fibers.

[0032] In the preparation method of the moisture-wicking and heat-insulating fiber described above, the processing line speed of air texturing composite is 300-600m / min.

[0033] The present invention also provides a moisture-wicking and heat-retaining fiber, which is prepared by the method described in any of the preceding claims; the equivalent diameter of the loop (i.e., the length of the down cluster along the radial direction of the core filament) is 0.2-40 mm, the length of the down cluster along the axial direction of the core filament is 0.5-50 mm, and the distance between two adjacent down clusters is 0.5-20 mm; this structural size range allows the fiber to form a three-dimensional fluffy shape that mimics natural down, taking into account both warmth retention and moisture-wicking performance.

[0034] The present invention also provides an application of a moisture-wicking and heat-insulating fiber as described above, wherein the moisture-wicking and heat-insulating fiber is used directly as a filler in the form of loose fibers or flakes without being cut or woven.

[0035] As a preferred technical solution:

[0036] As described above, the compression recovery rate of the filling is 63.7%-90.2%, the compression rate is 45.6%-63.1%, the insulation rate is 64.4%-90.6%, the clo value is ≥2.0clo, the insulation retention rate after 30 professional washes is ≥72.9% (compared to 70-75% for conventional down jackets), the clo value retention rate after 30 professional washes is ≥71.2% (compared to 70-75% for conventional down jackets), the air permeability is ≥1750mm / s, the moisture permeability is ≥5590g / (m²·24h), and the unidirectional transfer index is ≥461.

[0037] Beneficial effects:

[0038] (1) By controlling the overfeed rate and air supply pressure of the air-textured composite, the present invention enables the down to form an intermittent down cluster structure that mimics natural down, giving the fiber high loft and excellent warmth retention. The core filament, as a skeleton, can effectively prevent the fiber from being flattened and brittle.

[0039] (2) The present invention uses solid irregular cross-section core wire, which enables the fiber to have active moisture absorption and perspiration function, thus solving the technical problem that the moisture cannot be discharged and the traditional thermal insulation filling material is easy to sweat.

[0040] (3) The fiber obtained by the present invention is a continuous filament structure, which can be used directly as filling material without cutting or weaving, thus fundamentally solving the problem of feather leakage in traditional down feathers.

[0041] (4) The present invention stabilizes the tuft morphology through heat setting process, improves the stability of fiber structure, and ensures the long-term performance of fiber. Attached Figure Description

[0042] Figure 1 This is a scanning electron microscope (SEM) image of the cross-section of the filaments used in Example 3;

[0043] Figure 2 and Figure 3This is a scanning electron microscope image of the core wire used in Example 4. Figure 2 For cross-section, Figure 3 This is the longitudinal section;

[0044] Figure 4 The image shows the actual moisture-wicking and heat-retaining fiber prepared in Example 5; where 1-fleece, 2-core filament, 3-loop, and 4-fleece cluster. Detailed Implementation

[0045] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0046] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0047] Hollowness: The ratio of the hollow area to the total cross-sectional area of ​​the fiber is calculated by observing the cross-section of the fiber under a microscope and using image analysis.

[0048] Compression ratio and compression recovery rate: tested according to GB / T 22796-2021 standard, with a sample weight of 450 g / m³. 2 .

[0049] Thermal insulation rate: Tested according to FZ / T 64003-2021 "Spray-bonded cotton wadding sheet" standard, where the sample weight is 150g / m². 2 .

[0050] Cro value: Thermal resistance obtained by testing according to GB / T 11048-2018 (evaporative hot plate method), 1 Cro value equals 0.155m. 2 The thermal resistance value in K / W was converted to the Crowe value, where the sample weight was 100 g / m³. 2 .

[0051] Air permeability: Tested according to GB / T 5453-2023 "Textiles - Determination of Air Permeability of Fabrics", with a sample weight of 150 g / m². 2 .

[0052] Moisture permeability: Tested according to Method A in GB / T 12704.2-2009 standard, where the sample weight is 150 g / m³. 2 .

[0053] Unidirectional transfer index: Tested according to GB / T 21655.2-2019 standard, where the sample weight is 150 g / m³. 2 .

[0054] In the following text, "professional water washing" refers to the GB / T 8629-2017 standard.

[0055] In the following text, the "air texturing composite" refers to the RM3-T air texturing machine manufactured by Rieter Holding AG of Switzerland.

[0056] In the following text, the "hydrophilic masterbatch" refers to the BH-PET type hydrophilic masterbatch from Suzhou Polydi Materials Technology Co., Ltd.

[0057] Example 1

[0058] A method for preparing a moisture-wicking and heat-retaining fiber, the specific steps of which are as follows:

[0059] (1) Material preparation;

[0060] Core filament: Solid irregular cross-section fiber with a cross-sectional shape of "+", irregularity of 15%, material is a mixture of PET and hydrophilic masterbatch (hydrophilic masterbatch content is 0.5wt%), monofilament linear density is 1.25dtex, and bus density is 30dtex;

[0061] Fleece: A long filament with a hollow structure, a circular hollow cross-section, a hollowness of 15%, made of PA6, with a single filament linear density of 0.83 dtex and a bus density of 20 dtex;

[0062] (2) Preparation of composite filaments;

[0063] Composite filaments are obtained by combining two continuous filaments, core filament and fleece filament, through air texturing. The relevant process parameters for air texturing are: overfeed rate of fleece filament is 1000%, overfeed rate of core filament is 0%, air supply pressure is 0.5MPa, and processing line speed is 300m / min.

[0064] (3) Preparation of moisture-wicking and heat-insulating fibers;

[0065] The composite filaments are heat-set to obtain moisture-wicking and warm fibers. The relevant process parameters for heat setting are: temperature 100℃, time 30s, tension 0cN / dtex, and overfeed rate 3%.

[0066] In the final moisture-wicking and heat-insulating fiber, the equivalent diameter of the loop is 0.2-10mm, the average equivalent diameter of the loop is 3.2mm, the length of the pile along the core filament axis is 0.5-15mm, the average length of the pile along the core filament axis is 5.5mm, and the distance between two adjacent piles is 15-20mm.

[0067] The moisture-wicking and heat-insulating fiber prepared in this embodiment can be used directly as a filler in the form of loose fibers or wadding without cutting or weaving. The compression recovery rate of the filler is 70.6%, the compression rate is 59.7%, the heat retention rate is 70.4%, the clo value is 2.2clo, the heat retention rate retention rate is 80.3% after 30 professional washings, the clo value retention rate is 80.5% after 30 professional washings, the air permeability is 2100mm / s, the moisture permeability is 6630g / (m²·24h), and the unidirectional transfer index is 606.

[0068] Example 2

[0069] A method for preparing a moisture-wicking and heat-retaining fiber, the specific steps of which are as follows:

[0070] (1) Material preparation;

[0071] Core filament: Solid irregular cross-section fiber with a Y-shaped cross-section, an irregularity of 35%, and a material of PBT and hydrophilic masterbatch (hydrophilic masterbatch content of 3wt%). The monofilament linear density is 2.08dtex and the bus density is 150dtex.

[0072] Filament: A long filament with a hollow structure, a C-shaped hollow cross-section, a hollowness of 45%, made of PBT, with a single filament linear density of 1.5 dtex and a bus density of 54 dtex;

[0073] (2) Preparation of composite filaments;

[0074] Composite filaments are obtained by combining two continuous filaments, core filament and fleece filament, through air texturing. The relevant process parameters for air texturing are: overfeed rate of fleece filament 4000%, overfeed rate of core filament 5%, air supply pressure 2.5MPa, and processing line speed 600m / min.

[0075] (3) Preparation of moisture-wicking and heat-insulating fibers;

[0076] The composite filaments are heat-set to obtain moisture-wicking and warm fibers. The relevant process parameters for heat setting are: temperature 190℃, time 80s, tension 0cN / dtex, and overfeed rate 8%.

[0077] In the final moisture-wicking and heat-insulating fiber, the equivalent diameter of the loop is 20-40mm, the average equivalent diameter of the loop is 29.1mm, the length of the pile along the core filament axis is 25-50mm, the average length of the pile along the core filament axis is 34.3mm, and the distance between two adjacent piles is 0.5-5mm.

[0078] The moisture-wicking and heat-insulating fiber prepared in this embodiment can be used directly as a filler in the form of loose fibers or wadding without cutting or weaving. The compression recovery rate of the filler is 90.2%, the compression rate is 45.6%, the heat retention rate is 90.6%, the clo value is 2.5clo, the heat retention rate retention rate is 88.5% after 30 professional washings, the clo value retention rate is 87.7% after 30 professional washings, the air permeability is 2500mm / s, the moisture permeability is 7210g / (m²·24h), and the unidirectional transfer index is 687.

[0079] Example 3

[0080] A method for preparing a moisture-wicking and heat-retaining fiber, the specific steps of which are as follows:

[0081] (1) Material preparation;

[0082] Core filament: Solid irregular cross-section fiber with a W-shaped cross-section and an irregularity of 25%. The material is a mixture of PTT and hydrophilic masterbatch (the content of hydrophilic masterbatch is 1.8wt%). The monofilament linear density is 5dtex and the bus density is 120dtex.

[0083] Filament: A long filament with a hollow structure, an O-shaped porous hollow cross-section, a hollowness of 30%, made of PLA, with a single filament linear density of 3 dtex and a bus density of 100 dtex. A scanning electron microscope image of the cross-section is shown below. Figure 1 As shown;

[0084] (2) Preparation of composite filaments;

[0085] Composite filaments are obtained by combining two continuous filaments, core filament and fleece filament, through air texturing. The relevant process parameters for air texturing are: overfeed rate of fleece filament is 2500%, overfeed rate of core filament is 2.5%, air supply pressure is 1.5MPa, and processing line speed is 450m / min.

[0086] (3) Preparation of moisture-wicking and heat-insulating fibers;

[0087] The composite filaments are heat-set to obtain moisture-wicking and warm fibers. The relevant process parameters for heat setting are: temperature 145℃, time 55s, tension 0cN / dtex, and overfeed rate 5.5%.

[0088] The final moisture-wicking and heat-insulating fiber has an equivalent diameter of 10-28 mm, an average equivalent diameter of 17.5 mm, a tuft length along the core filament axis of 15-35 mm, an average tuft length along the core filament axis of 19.6 mm, and a spacing of 8-17 mm between two adjacent tufts.

[0089] The moisture-wicking and heat-insulating fiber prepared in this embodiment can be used directly as a filler in the form of loose fibers or flakes without cutting or weaving. The compression recovery rate of the filler is 82.3%, the compression rate is 52.2%, the heat retention rate is 80.5%, the clo value is 2.3clo, the heat retention rate retention rate is 83.2% after 30 professional washings, the clo value retention rate is 84.1% after 30 professional washings, the air permeability is 2300mm / s, the moisture permeability is 6960g / (m²·24h), and the unidirectional transfer index is 655.

[0090] Example 4

[0091] A method for preparing a moisture-wicking and heat-retaining fiber, the specific steps of which are as follows:

[0092] (1) Material preparation;

[0093] Core filament: Solid irregular cross-section fiber, octagonal in shape, with an irregularity of 20%, made of a mixture of PBT and hydrophilic masterbatch (hydrophilic masterbatch content 1.2wt%), with a single filament linear density of 1 dtex and a bus density of 72 dtex. Cross-sectional scanning electron microscopy (SEM) results are shown below. Figure 2 and Figure 3 As shown;

[0094] Filament: A long filament with a hollow structure, a cross-sectional shape of "8" hollow, a hollowness of 22%, made of PTT, with a single filament linear density of 0.5 dtex and a bus density of 36 dtex;

[0095] (2) Preparation of composite filaments;

[0096] Composite filaments are obtained by combining two continuous filaments, core filament and fleece filament, through air texturing. The relevant process parameters for air texturing are: overfeed rate of fleece filament is 1800%, overfeed rate of core filament is 1.2%, air supply pressure is 0.9MPa, and processing line speed is 380m / min.

[0097] (3) Preparation of moisture-wicking and heat-insulating fibers;

[0098] The composite filament is heat-set to obtain moisture-wicking and warm fiber. The relevant process parameters for heat setting are: temperature 130℃, time 45s, tension 0cN / dtex, and overfeed rate 4.5%.

[0099] In the final moisture-wicking and heat-insulating fiber, the equivalent diameter of the loop is 5-20mm, the average equivalent diameter of the loop is 11.3mm, the length of the pile along the core filament axis is 10-25mm, the average length of the pile along the core filament axis is 12.2mm, and the distance between two adjacent piles is 12-18mm.

[0100] The moisture-wicking and heat-insulating fiber prepared in this embodiment can be used directly as a filler in the form of loose fibers or wadding without cutting or weaving. The compression recovery rate of the filler is 78.3%, the compression rate is 55.4%, the heat retention rate is 75.7%, the clo value is 2.2clo, the heat retention rate retention rate is 81.6% after 30 professional washings, the clo value retention rate is 80.9% after 30 professional washings, the air permeability is 2150mm / s, the moisture permeability is 6740g / (m²·24h), and the unidirectional transfer index is 628.

[0101] Example 5

[0102] A method for preparing a moisture-wicking and heat-retaining fiber, the specific steps of which are as follows:

[0103] (1) Material preparation;

[0104] Core filament: Solid irregular cross-section fiber with a cross-sectional shape of "+", irregularity of 28%, material is a mixture of PET and hydrophilic masterbatch (hydrophilic masterbatch content is 2.5wt%), single filament linear density is 2dtex, and bus density is 96dtex.

[0105] Fleece: A long filament with a hollow structure, a circular hollow cross-section, a hollowness of 38%, made of PA6, with a single filament linear density of 1 dtex and a bus density of 72 dtex;

[0106] (2) Preparation of composite filaments;

[0107] Composite filaments are obtained by combining two continuous filaments, core filament and fleece filament, through air texturing. The relevant process parameters for air texturing are: overfeed rate of fleece filament 3200%, overfeed rate of core filament 4%, air supply pressure 2MPa, and processing line speed 520m / min.

[0108] (3) Preparation of moisture-wicking and heat-insulating fibers;

[0109] The composite filaments are heat-set to obtain moisture-wicking and warm fibers. The relevant process parameters for heat setting are: temperature 175℃, time 70s, tension 0cN / dtex, and overfeed rate 6.5%.

[0110] like Figure 4 As shown, the final moisture-wicking and warm fiber consists of a core filament 2 and a down filament 1. The core filament 2 is in a straight state, while the down filament 1 is in a non-straight state and has a length that is longer than that of the core filament 2. The extra length of the down filament 1 is wrapped around the surface of the core filament 2 in an irregular loop 3 to form down clusters similar to natural down. The down clusters intermittently gather along the axis of the core filament 2 to form down tufts 4.

[0111] In moisture-wicking and heat-retaining fibers, the equivalent diameter of the loop is 15-35mm, the average equivalent diameter of the loop is 22.4mm, the length of the pile along the core filament axis ranges from 20-45mm, the average length of the pile along the core filament axis is 25.1mm, and the distance between two adjacent piles is 2.5-10mm.

[0112] The moisture-wicking and heat-insulating fiber prepared in this embodiment can be used directly as a filler in the form of loose fibers or wadding without cutting or weaving. The compression recovery rate of the filler is 86.5%, the compression rate is 48.3%, the heat retention rate is 85.3%, the clo value is 2.4clo, the heat retention rate retention rate is 85.4% after 30 professional washings, the clo value retention rate is 86.8% after 30 professional washings, the air permeability is 2400mm / s, the moisture permeability is 7070g / (m²·24h), and the unidirectional transfer index is 661.

[0113] Comparative Example 1

[0114] A method for preparing a fiber differs from Example 1 only in that the cross-sectional shape of the core filament is circular.

[0115] In the final fiber, the equivalent diameter of the loop is 0.2-8mm (because the core filament has no sharp edges, the loop formation is insufficient), the average equivalent diameter of the loop is 2.6mm, the length of the tuft along the core filament axis ranges from 0.5-20mm, the average length of the tuft along the core filament axis is 6.3mm, and the distance between two adjacent tufts is 13-17mm.

[0116] The fibers prepared in this comparative example were used directly as fillers in the form of loose fibers or flakes. The compression recovery rate of the filler was 58.5%, the compression rate was 68.1%, the heat retention rate was 62.7%, the clo value was 1.8clo, the heat retention rate retention rate was 68.1% after 30 professional water washings, the clo value retention rate was 65.3% after 30 professional water washings, the air permeability was 1500mm / s, the moisture permeability was 5250g / (m²·24h), and the unidirectional transfer index was 424.

[0117] Compared with Comparative Example 1 and Example 1, the unidirectional transfer index, moisture permeability, compression recovery rate, heat retention rate, Clo value, heat retention rate retention rate after washing, Clo value retention rate after washing, and air permeability were all significantly reduced, while the compression rate was significantly increased. This is because the circular cross-section core filament has no longitudinal grooves on its surface, making it impossible to form continuous capillary channels to achieve efficient core absorption and moisture conduction. At the same time, the circular core filament has low bending stiffness and a smooth surface, which cannot effectively support the filaments to form stable loops and tufts. The amount of static air stored between fibers is greatly reduced, and there is no mechanical anchoring effect between the core filament and the filaments. During washing, the tufts are prone to irreversible slippage and entanglement, and the fibers are also more easily compacted and hardened.

[0118] Comparative Example 2

[0119] A method for preparing fibers differs from Example 1 only in that the overfeed rate of the filaments is 950%.

[0120] In the final fiber, the equivalent diameter of the loops is 0.1-8 mm, the average equivalent diameter of the loops is 1.8 mm, the length of the tufts along the core filament axis is 0.3-12 mm, the average length of the tufts along the core filament axis is 4.1 mm, and the distance between two adjacent tufts is 18-30 mm (because the loops become smaller and fewer, the distance increases instead).

[0121] The fibers prepared in this comparative example were used directly as fillers in the form of loose fibers or flakes. The compression recovery rate of the filler was 55.3%, the compression rate was 70.1%, the heat retention rate was 58.6%, the clo value was 1.7clo, the heat retention rate retention rate was 65.2% after 30 professional washings, the clo value retention rate was 63.9% after 30 professional washings, the air permeability was 1630mm / s, the moisture permeability was 5470g / (m²·24h), and the unidirectional transfer index was 443.

[0122] Compared with Example 1, Comparative Example 2 showed a significant decrease in compression recovery rate, heat retention rate, Clo value, heat retention rate retention rate after washing, Clo value retention rate after washing, unidirectional transfer index, moisture permeability, and air permeability, while the compression rate increased significantly. This is because the overfeed rate of the pile filaments was insufficient, resulting in insufficient excess length of pile filaments per unit length of core filament, which could not form sufficiently sized loops and tufts. The three-dimensional fluffy structure was greatly weakened, and the fiber's ability to capture still air was significantly reduced. The insufficient entanglement strength between the pile filaments and core filaments made the structure easily damaged after washing. At the same time, the excessively small loops and tufts narrowed the pore channels between fibers, hindering the migration of water vapor and liquid water.

[0123] Comparative Example 3

[0124] A method for preparing a fiber differs from Example 1 only in that the gas supply pressure is 0.45 MPa.

[0125] In the final fiber, the equivalent diameter of the loop is 0.1-8mm, the average equivalent diameter of the loop is 2.1mm, the length of the tuft along the core filament axis is 0.4-18mm, the average length of the tuft along the core filament axis is 6.4mm (due to the low air supply pressure, the tuft diameter is small, so it is stretched in the axial direction), and the distance between two adjacent tufts is 12-18mm.

[0126] The fiber prepared in this comparative example is directly used as a filler in the form of loose fiber or batting, and the filler has a compression recovery rate of 56.0%, a compression rate of 71.5%, a heat retention rate of 57.4%, a CLO value of 1.7clo, a heat retention rate retention rate of 64.3% after 30 professional washing cycles, a CLO value retention rate of 64.7% after 30 professional washing cycles, an air permeability of 1620mm / s, a moisture vapor transmission rate of 5530g / (m²·24h), and a one-way transmission index of 431.

[0127] Compared with Example 1, Comparative Example 3 shows significantly reduced compression recovery rate, heat retention rate, CLO value, heat retention rate retention rate after washing, CLO value retention rate after washing, one-way transmission index, moisture vapor transmission rate and air permeability, and a significantly increased compression rate. This is because the gas supply pressure is too low, so that the pile filaments cannot form loops and pile clusters of sufficient size on the surface of the core filament, the three-dimensional fluffy structure is greatly weakened, the ability of the fiber to capture still air is significantly reduced, the insufficient entanglement strength between the pile filaments and the core filament leads to easy structural damage after washing, and meanwhile, the excessively small loops and pile clusters narrow the pore channels between fibers, which hinders the migration of water vapor and liquid water.

[0128] Example 6

[0129] A method for preparing a moisture-absorbing, sweat-releasing and heat-retaining fiber differs from Example 2 only in that the cross-sectional shape of the core filament is a Wang (king)-shape.

[0130] In the finally prepared moisture-absorbing, sweat-releasing and heat-retaining fiber, the equivalent diameter of the loops is 20-40mm, the average value of the equivalent diameter of the loops is 28.6mm, the axial length of the pile clusters along the core filament ranges from 25 to 50mm, the average value of the axial length of the pile clusters along the core filament is 34.7mm, and the spacing between two adjacent pile clusters is 0.5-5mm.

[0131] The moisture-absorbing, sweat-releasing and heat-retaining fiber prepared in this example is directly used as a filler in the form of loose fiber or batting, and the filler has a compression recovery rate of 84.3%, a compression rate of 50.2%, a heat retention rate of 84.6%, a CLO value of 2.35clo, a heat retention rate retention rate of 83.7% after 30 professional washing cycles, a CLO value retention rate of 82.1% after 30 professional washing cycles, an air permeability of 2350mm / s, a moisture vapor transmission rate of 6880g / (m²·24h), and a one-way transmission index of 641.

[0132] Compared with Example 2, Example 6 showed a decrease in compression recovery rate, heat retention rate, Clo value, heat retention rate retention rate after washing, Clo value retention rate after washing, air permeability, moisture permeability, and unidirectional transfer index, while the compression rate increased. This is because the edges of the king-shaped cross-section core filament are narrower and the grooves are shallower and wider, which weakens the mechanical anchoring effect on the pile filaments. The pile filaments are more likely to slip off, resulting in a reduction in the size of the loops and pile clusters, a decrease in fiber bulkiness and static air storage capacity, and insufficient capillary driving force of the grooves, which leads to a decrease in liquid water migration efficiency. During washing, the pile filaments are more likely to slip along the core filament axis, resulting in poorer structural stability.

[0133] Example 7

[0134] A method for preparing a moisture-wicking and heat-retaining fiber differs from Example 2 only in that the cross-sectional shape of the core filament is a star shape.

[0135] In the final moisture-wicking and heat-retaining fiber, the equivalent diameter of the loop is 20-36mm, the average equivalent diameter of the loop is 28.1mm, the length of the pile along the core filament axis is 25-50mm, the average length of the pile along the core filament axis is 34.9mm, and the distance between two adjacent piles is 0.3-5mm.

[0136] The moisture-wicking and heat-insulating fibers prepared in this embodiment are used directly as fillers in the form of loose fibers or wadding. The compression recovery rate of the filler is 81.1%, the compression rate is 53.7%, the heat retention rate is 80.3%, the clo value is 2.25clo, the heat retention rate retention rate is 80.5% after 30 professional washings, the clo value retention rate is 79.8% after 30 professional washings, the air permeability is 2250mm / s, the moisture permeability is 6630g / (m²·24h), and the unidirectional transfer index is 622.

[0137] Compared with Example 2, Example 7 showed a decrease in compression recovery rate, heat retention rate, Cro value, heat retention rate retention rate after washing, Cro value retention rate after washing, air permeability, moisture permeability, and unidirectional transfer index, while the compression rate increased. This is because the edges of the cross-shaped core yarn are fine and sharp, and the grooves are narrow and shallow, which is insufficient for the effective support and anchoring of the pile yarn and easily damages the pile yarn, resulting in a further reduction in the size of the loops and pile clusters, and deterioration of the fiber's fluffy structure. At the same time, water film blockage in the grooves easily hinders water vapor transfer, and the hidden damage to the pile yarn leads to more severe structural damage after washing, and the airflow resistance also increases accordingly.

[0138] Example 8

[0139] A method for preparing a moisture-wicking and heat-retaining fiber differs from Example 1 only in that the cross-sectional shape of the core filament has an anisotropy of 10%.

[0140] In the final moisture-wicking and heat-insulating fiber, the equivalent diameter of the loop is 0.2-10mm, the average equivalent diameter of the loop is 3.1mm, the length of the pile along the core filament axis is 0.5-15mm, the average length of the pile along the core filament axis is 5.7mm, and the distance between two adjacent piles is 14-19mm.

[0141] The moisture-wicking and heat-insulating fibers prepared in this embodiment are used directly as fillers in the form of loose fibers or wadding. The compression recovery rate of the filler is 63.7%, the compression rate is 61.3%, the heat retention rate is 64.4%, the clo value is 2.0clo, the heat retention rate retention rate is 74.2% after 30 professional washings, the clo value retention rate is 73.1% after 30 professional washings, the air permeability is 1750mm / s, the moisture permeability is 5590g / (m²·24h), and the unidirectional transfer index is 461.

[0142] Example 9

[0143] A method for preparing a moisture-wicking and heat-retaining fiber differs from Example 4 only in that the irregularity of the cross-sectional shape of the core filament is 10%.

[0144] In the final moisture-wicking and heat-insulating fiber, the equivalent diameter of the loop is 5-20mm, the average equivalent diameter of the loop is 10.8mm, the length of the pile along the core filament axis is 10-25mm, the average length of the pile along the core filament axis is 12.6mm, and the distance between two adjacent piles is 11-17mm.

[0145] The moisture-wicking and heat-insulating fibers prepared in this embodiment are used directly as fillers in the form of loose fibers or wadding. The compression recovery rate of the filler is 66.5%, the compression rate is 63.1%, the heat retention rate is 68.6%, the clo value is 2.0clo, the heat retention rate retention rate is 72.9% after 30 professional washings, the clo value retention rate is 71.2% after 30 professional washings, the air permeability is 1750mm / s, the moisture permeability is 5630g / (m²·24h), and the unidirectional transfer index is 563.

[0146] Compared with Examples 1 and 4, Examples 8 and 9 show a decrease in compression recovery rate, heat retention rate, clo value, heat retention rate retention after washing, clo value retention rate after washing, air permeability, moisture permeability, and unidirectional transfer index, while the compression rate increases. This is because the core yarn profile is too low, and there are almost no capillary grooves on the surface, making it impossible to form efficient wicking channels. Moisture can only be transferred by the fiber's extremely low moisture absorption capacity, resulting in a significant decrease in moisture absorption and wicking properties. Simultaneously, the excessively low profile makes the core yarn surface too smooth, hindering its interaction with the down. The friction and mechanical anchoring between the fibers are greatly reduced, making the pile fibers very easy to slip off the surface of the core fibers. The pile and loop structures are easily damaged, and the bulkiness of the fiber assembly is greatly reduced. This not only reduces the ability to trap still air, but also makes it easier to be compacted, resulting in poorer warmth retention and compression recovery performance. In addition, the slippage of the pile fibers also leads to a reduction in the effective interconnected pores between fibers, an increase in airflow resistance, and a further reduction in air permeability. During the washing process, the pile and loops are prone to irreversible deformation and detachment, ultimately resulting in a significant decrease in the performance retention rate after washing.

Claims

1. A method for preparing a moisture-wicking and heat-retaining fiber, characterized in that, First, the core filament and the fleece filament are combined by air texturing to obtain a composite filament. Then, the composite filament is heat-set to obtain a moisture-wicking and heat-insulating fiber. In the process of air texturing and compounding, the overfeed rate of the core filament and the down filament is controlled so that the core filament is in a straight state and the down filament is in a non-straight state with an excess length relative to the core filament. At the same time, the air supply pressure is controlled so that under the action of airflow, the excess length of the down filament wraps around the surface of the core filament in an irregular loop shape, forming down clusters similar to natural down, and the down clusters intermittently gather along the core filament axis to form down tufts. The core filament is a solid, irregularly shaped fiber; The cross-sectional shape of the core wire is "+", Y, W or octagonal. The irregularity of the cross-sectional shape of the core wire is 15%-35%. Irregularity = (area of ​​the circumcircle of the irregular cross-section - actual area of ​​the irregular cross-section) × 100% / area of ​​the circumcircle of the irregular cross-section. The polymer matrix of the core filament is PET, PTT or PBT; the core filament contains 0.5-3.0 wt% hydrophilic masterbatch; The filaments are long filaments with a hollow structure. Their cross-sectional shape is circular hollow, C-shaped hollow, O-shaped porous hollow, or "8"-shaped hollow, with a hollowness of 15%-45%. The polymer matrix of the filaments is PA6, PBT, PTT, or PLA. The overfeed rate of the pile yarn is 1000%-4000%, and the overfeed rate of the core yarn is 0%-5%. The overfeed rate of the pile yarn is higher than that of the core yarn, and the difference between the two is at least 1000%. The air supply pressure is 0.5-2.5MPa; the processing speed of air texturing composite is 300-600m / min.

2. The method for preparing a moisture-wicking and heat-retaining fiber according to claim 1, characterized in that, The heat setting temperature is 100-190℃, the time is 30-80s, the tension is 0cN / dtex, and the overfeed rate is 3%-8%.

3. The method for preparing a moisture-wicking and heat-retaining fiber according to claim 1, characterized in that, The core filament has a single filament linear density of 1.0-5.0 dtex and a bus density of 30-150 dtex; the fleece filament has a single filament linear density of 0.5-3.0 dtex and a bus density of 20-100 dtex; the ratio of the bus density of the core filament to the bus density of the fleece filament is 1.2-2.8:

1.

4. A moisture-wicking and heat-retaining fiber, characterized in that, The fiber is prepared by the method described in any one of claims 1-3, wherein the equivalent diameter of the loop is 0.2-40 mm, the length of the pile along the core filament axis is 0.5-50 mm, and the distance between two adjacent piles is 0.5-20 mm.

5. The application of the moisture-wicking and heat-retaining fiber as described in claim 4, characterized in that, The moisture-wicking and heat-retaining fibers are used directly as fillers in the form of loose fibers or wadding without being cut or woven. The compression recovery rate of the filler is 63.7%-90.2%, the compression rate is 45.6%-63.1%, the heat retention rate is 64.4%-90.6%, the clo value is ≥2.0clo, the heat retention rate retention rate is ≥72.9% after 30 professional washings, the clo value retention rate is ≥71.2% after 30 professional washings, the air permeability is ≥1750mm / s, the moisture permeability is ≥5590g / (m²·24h), and the unidirectional transfer index is ≥461.

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