A method for producing a dual-core moisture-conducting functional fiber

Abstract

The present application relates to the technical field of functional fiber material, in particular to a preparation method of double-core moisture-conducting functional fiber, comprising the following steps: S1, preparing inner core spinning solution, outer core spinning solution and skin layer spinning solution respectively; S2, first, the inner core spinning solution obtained in step S1 is subjected to wet spinning, and then the obtained inner core fiber is subjected to cooling, stretching and heat setting to obtain the inner core fiber; the inner core fiber is passed through the center of a ring-shaped jet orifice covering head of a single-screw extruder, the outer core spinning solution obtained in step S1 is subjected to melt extrusion, and then the obtained outer core layer is subjected to cooling, stretching and heat setting to obtain a double-core fiber; the double-core fiber is introduced into the center of the ring-shaped jet orifice covering head again, the skin layer spinning solution obtained in step S1 is subjected to melt extrusion and uniformly coated on the surface of the double-core fiber, and then the obtained double-core fiber is subjected to cooling, stretching and heat setting to obtain a double-core moisture-conducting functional fiber. The double-core moisture-conducting functional fiber prepared by the present application has the advantages of high moisture-conducting efficiency and strong one-way transmission capacity.

Description

Technical Field

[0001] This invention relates to the field of functional fiber materials technology, and specifically to a method for preparing a dual-core moisture-wicking functional fiber. Background Technology

[0002] With the rapid development of the sportswear, medical dressings, military clothing, and functional textiles markets, consumers are increasingly demanding higher levels of comfort in clothing. Among these demands, moisture management has become a key indicator for evaluating high-performance textiles. The human body sweats profusely during exercise or in high-temperature environments. If clothing materials cannot effectively wick away and evaporate this sweat, it can lead to a damp, cold feeling, a sticky sensation, and even skin problems. Therefore, developing new fiber materials with highly efficient moisture-wicking and quick-drying properties has become a hot research topic in the industry.

[0003] Currently, moisture-wicking functional fibers are mainly achieved through three approaches: First, using irregularly shaped cross-section fibers, such as cross-shaped or trilobal shapes, to provide capillary conduction channels by increasing grooves on the fiber surface; second, through hydrophilic and hydrophobic finishing, forming a wettability gradient on the fabric surface to achieve unidirectional moisture wicking; and third, constructing a core-sheath composite structure, with the core layer being a hydrophilic material and the sheath layer being a hydrophobic material, utilizing the capillary effect to draw moisture from the sheath layer into the core layer.

[0004] In the prior art, patent CN101629334B discloses an anti-UV, antibacterial, and moisture-wicking polyester fiber, its preparation method, and its applications. The polyester fiber disclosed in this invention is composed of the following raw materials in weight percentages: 1-5% anti-UV masterbatch, 1-10% silver-based antibacterial masterbatch, and 85-98% polyester fiber-forming resin. The fiber cross-section is an irregular shape. The polyester fiber provided by this invention has a scientifically reasonable component ratio. By scientifically combining the antibacterial silver-based antibacterial masterbatch, anti-UV masterbatch, and polyester fiber-forming resin, and preparing pre-oriented yarn through an irregularly shaped spinning plate, and then producing low-elasticity textured yarn through texturing, a multifunctional polyester fiber with antibacterial, anti-UV, and moisture-wicking properties is obtained, with a wide range of applications. However, although the irregularly shaped cross-section fiber has a certain moisture-wicking capacity, moisture is mainly transported axially along the fiber surface, lacking a transverse conduction mechanism, resulting in limited moisture-wicking efficiency and unavoidable backflow.

[0005] Patent CN114875552B discloses a preparation process for a double-strand, double-core spandex elastic fiber denim fabric. The preparation process includes the following steps: S1: Twisting DTY filaments and spandex filaments into a double-core yarn, then wrapping the double-core yarn with cotton yarn to obtain a single-strand yarn, and then twisting two single-strand yarns together to form a double-strand, double-core yarn; S2: Weaving the double-strand, double-core yarn into a greige fabric; S3: Performing a first setting, pretreatment, dyeing, soaping, washing, and a second setting on the greige fabric to obtain the double-strand, double-core elastic fiber denim fabric. This method gives the denim fabric good elasticity, breathability, moisture absorption, and softness. However, in the core-sheath structure fiber, the hydrophilic material in the core layer easily swells after absorbing water, clogging capillary channels and leading to a decrease in moisture-wicking performance.

[0006] Therefore, there is an urgent need in the market for a dual-core moisture-wicking functional fiber with high moisture-wicking efficiency and strong unidirectional transmission capability. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of this invention is to obtain a dual-core moisture-wicking functional fiber with high moisture-wicking efficiency and strong unidirectional transmission capability.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for preparing a dual-core moisture-wicking functional fiber, comprising the following steps: S1. Prepare the inner core spinning solution, outer core spinning solution and skin spinning solution respectively; S2. First, the inner core spinning solution obtained in step S1 is wet-spun, cooled, stretched, and heat-set to obtain the inner core fiber. The inner core fiber is passed through the annular spinneret of a single-screw extruder to cover the center of the die head. The outer core spinning solution obtained in step S1 is melt-extruded, cooled, stretched, and heat-set to form an outer core layer to obtain a double core fiber. The double core fiber is introduced into the annular spinneret again to cover the center of the die head. The outer layer spinning solution obtained in step S1 is melt-extruded to uniformly cover the surface of the double core fiber. After cooling, stretching, and heat-setting, a double core moisture-wicking functional fiber is obtained.

[0009] Preferably, the preparation method of the dual-core moisture-wicking functional fiber includes the following steps: S1. Prepare the inner core spinning solution, outer core spinning solution and skin spinning solution respectively; S2. First, the inner core spinning solution obtained in step S1 is wet-spun, cooled, stretched, and heat-set at 80-100℃ to obtain inner core fibers. The stretching temperature is 85-90℃, and the stretching ratio is 3-5 times. The inner core fibers are passed through the annular spinneret of a single-screw extruder to cover the center of the die head. The outer core spinning solution obtained in step S1 is melt-extruded, cooled, stretched, and heat-set at 105-110℃ to form an outer core layer to obtain double-core fibers. The stretching temperature is 60-70℃, and the stretching ratio is 1.2-1.5 times. The double-core fibers are introduced back into the annular spinneret to cover the center of the die head. The outer layer spinning solution obtained in step S1 is melt-extruded and uniformly coated on the surface of the double-core fibers. After cooling, stretching, and heat-setting at 95-100℃, double-core moisture-wicking functional fibers are obtained. The stretching temperature is 70-80℃, and the stretching ratio is 1.2-1.5 times.

[0010] Traditional moisture-wicking fibers typically have a bilayer structure, consisting of a hydrophobic outer layer and a hydrophilic core layer. However, the bonding between these two materials with significantly different hydrophilicities is weak at the composite interface, making them prone to delamination and peeling during spinning, stretching, or use, thus compromising structural integrity. Furthermore, when water moves from the hydrophobic layer to the hydrophilic layer, the lack of a transition layer prevents water from traversing the interface, leading to decreased moisture wicking efficiency and even water retention or backflow at the interface. This application proposes a method for preparing a three-layer concentric (inner core-outer core-outer layer) composite fiber, constructing a bilayer moisture-wicking fiber with gradient wetting capabilities. By designing a three-layer structure and introducing the outer core layer as an intermediate transition layer, the problem of hydrophilic gradient transition can be better solved, avoiding interlayer interface defects or decreased moisture wicking efficiency caused by significant differences in hydrophilicity.

[0011] In some embodiments, the preparation method of the inner core spinning solution includes the following steps: adding modified polyvinyl alcohol, sodium alginate, nano silica, polyvinylpyrrolidone, and crosslinking agent to deionized water, stirring and dissolving at 90-100°C to obtain the solution.

[0012] In some embodiments, the particle size of the nano-silica is 10-100 nm.

[0013] In some embodiments, the mass ratio of the modified polyvinyl alcohol to sodium alginate is 1:(0.35-0.45).

[0014] In some embodiments, the mass ratio of the modified polyvinyl alcohol to nano silica is 1:(0.025-0.035).

[0015] In some embodiments, the mass ratio of the modified polyvinyl alcohol to polyvinylpyrrolidone is 1:(0.05-0.15).

[0016] In some embodiments, the number-average molecular weight of the polyvinylpyrrolidone is 3000-5000.

[0017] In some embodiments, the crosslinking agent is glutaraldehyde, and the amount added is 0.5-1 wt% of the modified polyvinyl alcohol.

[0018] In some embodiments, the method for preparing the modified polyvinyl alcohol includes the following steps: adding polyvinyl alcohol to deionized water, heating to 90°C, stirring for 1-2 hours, cooling to 68-72°C, adding potassium persulfate and maintaining the temperature for 5-15 minutes to initiate the reaction, adding a mixture of acrylic acid and dodecyl mercaptan dropwise, continuing the reaction for 1-3 hours after the addition is complete, cooling to room temperature, precipitating in methanol, Soxhlet extraction, and vacuum drying to obtain modified polyvinyl alcohol.

[0019] Preferably, the mass ratio of polyvinyl alcohol, dodecyl mercaptan, and potassium persulfate is 1:(0.001-0.003):(0.001-0.005).

[0020] This application involves spinning an inner core fiber using a core spinning solution prepared by mixing modified polyvinyl alcohol, sodium alginate, nano-silica, polyvinylpyrrolidone, and deionized water. An outer core spinning solution is then spun onto the inner core fiber to obtain a double-core fiber. Finally, a sheath spinning solution is spun onto the outer layer of the double-core fiber, resulting in fibers with excellent moisture absorption and wicking properties. This is likely because: firstly, polyvinyl alcohol, after being modified by acrylic acid grafting, introduces carboxyl groups, improving its water absorption and ion exchange capacity; and secondly, sodium alginate contains a large number of sodium carboxylate groups, which form a hydrogel upon contact with water, and react with the modified polyvinyl alcohol... The alcohol forms an interpenetrating network, and the two work synergistically to enhance the water retention capacity of the inner core layer. At the same time, this application ensures that the inner core layer has sufficient water absorption capacity without clogging the channels due to excessive swelling by limiting the ratio of the two. On the other hand, nano-SiO2, as inorganic nanoparticles in the spinning solution, forms nanoscale micropores during the solidification process, increasing the specific surface area. At the same time, it acts as a "water molecule jumping point" to accelerate the diffusion of water molecules inside the fiber. Polyvinylpyrrolidone is not only a hydrophilic polymer, but it can also be partially dissolved in subsequent processing to form microporous channels, further improving the moisture wicking rate.

[0021] In some embodiments, the mass ratio of polyvinyl alcohol to acrylic acid is 1:(0.05-0.15).

[0022] In some embodiments, the preparation method of the outer core spinning solution includes the following steps: melting hydrophilic polyurethane at 160-170°C to obtain the solution.

[0023] Preferably, the hydrophilic polyurethane is Lubrizol Tecophilic TG-500.

[0024] In some embodiments, the preparation method of the skin spinning solution includes the following steps: melting hydrophobic polyurethane at 160-170°C to obtain the solution.

[0025] In some embodiments, the screw speed is 30-60 rpm.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention proposes a method for preparing a three-layer concentric circle (inner core-outer core-skin layer) composite fiber. By simultaneously spinning three spinning solutions, a dual-core moisture-wicking fiber with gradient wetting function is constructed, which can better solve the problem of hydrophilic gradient transition and improve the moisture-wicking efficiency of the dual-core moisture-wicking fiber.

[0027] (2) In this invention, an inner core spinning solution prepared by mixing modified polyvinyl alcohol, sodium alginate, nano silica, polyvinylpyrrolidone and deionized water is spun into an inner core fiber, and an outer core spinning solution is then spun onto the inner core fiber to obtain a double core fiber. Finally, a sheath spinning solution is spun onto the outer layer of the double core fiber, so that the obtained fiber has excellent moisture absorption and moisture wicking effect. Nano SiO2 acts as an inorganic nanoparticle in the spinning solution, forming nanoscale micropores during the solidification process, increasing the specific surface area. At the same time, it acts as a "water molecule jumping point" to accelerate the diffusion of water molecules inside the fiber. Polyvinylpyrrolidone is both a hydrophilic polymer and can be partially dissolved in subsequent processing to form microporous channels, further improving the moisture wicking rate.

[0028] (3) By using acrylic acid-modified polyvinyl alcohol, carboxyl groups are grafted onto its chain segments to improve its water absorption and ion exchange capacity, so that it forms an interpenetrating network with sodium alginate. The two work synergistically to enhance the water retention capacity of the inner core layer. At the same time, by limiting the ratio of the two, this application ensures that the inner core layer has sufficient water absorption capacity and will not block the channels due to excessive swelling, further improving the moisture absorption and wicking effect of the fiber. Detailed Implementation

[0029] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0030] All compounds and related reagents used in the following examples and comparative examples are commercially available. The average particle size of the nano-silica is 50 nm; the polyvinyl alcohol is PVA17-88; the number average molecular weight of polyvinylpyrrolidone is 4000; the hydrophilic polyurethane is Lubrizol Tecophilic TG-500, purchased from Dongguan Hengxin Plastic Raw Materials Co., Ltd.; and the hydrophobic polyurethane is Wanhua WHT-1195, purchased from Dongguan Chengjin Plastic Co., Ltd.

[0031] Preparation Example 1 The preparation method of modified polyvinyl alcohol-1 includes the following steps: 100g of polyvinyl alcohol is added to 1000ml of deionized water, heated to 90℃, stirred for 2h, nitrogen gas is purged for 30min, cooled to 70℃, 0.3g of potassium persulfate is added and kept warm for 8min to initiate the reaction, then a mixture of 10g of acrylic acid and 0.2g of dodecyl mercaptan is added dropwise, and the reaction is continued for 2h after the addition is completed. The mixture is cooled to room temperature, poured into 2000ml of methanol to precipitate, and Soxhlet extracted for 24h. The extractant is a mixture of methanol and acetone with a volume ratio of 1:1. The mixture is then vacuum dried at 50℃ to constant weight to obtain modified polyvinyl alcohol-1.

[0032] Preparation Example 2 The preparation method of modified polyvinyl alcohol-2 is the same as that in preparation example 1, except that the amount of acrylic acid added is 20g.

[0033] Preparation Example 3 The preparation method of the inner core spinning solution-1 includes the following steps: 100g of modified polyvinyl alcohol-1, 40g of sodium alginate, 3g of nano silica, 10g of polyvinylpyrrolidone, and 0.75g of glutaraldehyde are added to 1000ml of deionized water and stirred at 95℃ to dissolve, thus obtaining the solution.

[0034] Preparation Example 4 The preparation method of the inner core spinning solution-2 is the same as that in preparation example 1, except that the modified polyvinyl alcohol-1 is replaced by an equal amount of modified polyvinyl alcohol-2.

[0035] Preparation Example 5 The preparation method of the inner core spinning solution-3 is the same as that of preparation example 1, except that the modified polyvinyl alcohol-1 is replaced with an equal amount of polyvinyl alcohol.

[0036] Preparation Example 6 The preparation method of the outer core spinning solution includes the following steps: melting hydrophilic polyurethane at 155℃ to obtain the solution.

[0037] Preparation Example 7 The preparation method of the skin spinning solution includes the following steps: melting hydrophobic polyurethane at 175°C to obtain the solution. Example 1

[0038] A method for preparing a dual-core moisture-wicking functional fiber includes the following steps: S1. Prepare inner core spinning solution-1, outer core spinning solution and skin spinning solution respectively; S2. First, the inner core spinning solution-1 obtained in step S1 is wet-spun, cooled, stretched, and heat-set at 90°C to obtain the inner core fiber. The stretching temperature is 87°C and the stretching ratio is 4 times. The inner core fiber is passed through the annular spinneret of a single-screw extruder to cover the center of the die head. The outer core spinning solution obtained in step S1 is melt-extruded, cooled, stretched, and heat-set at 107°C to form the outer core layer and obtain the double core fiber. The stretching temperature is 65°C and the stretching ratio is 1.3 times. The double core fiber is introduced into the annular spinneret again to cover the center of the die head. The outer layer spinning solution obtained in step S1 is melt-extruded and uniformly coated on the surface of the double core fiber. After cooling, stretching, and heat-setting at 97°C, the double core moisture-wicking functional fiber is obtained. The stretching temperature is 75°C and the stretching ratio is 1.3 times. Example 2

[0039] A method for preparing a dual-core moisture-wicking functional fiber includes the following steps: S1. Prepare inner core spinning solution-1, outer core spinning solution and skin spinning solution respectively; S2. First, the inner core spinning solution-1 obtained in step S1 is wet-spun, cooled, stretched, and heat-set at 80°C to obtain the inner core fiber. The stretching temperature is 85°C and the stretching ratio is 4 times. The inner core fiber is passed through the annular spinneret of a single-screw extruder to cover the center of the die head. The outer core spinning solution obtained in step S1 is melt-extruded, cooled, stretched, and heat-set at 105°C to form the outer core layer to obtain the double core fiber. The stretching temperature is 60°C and the stretching ratio is 1.3 times. The double core fiber is introduced into the annular spinneret again to cover the center of the die head. The outer layer spinning solution obtained in step S1 is melt-extruded and uniformly coated on the surface of the double core fiber. After cooling, stretching, and heat-setting at 95°C, the double core moisture-wicking functional fiber is obtained. The stretching temperature is 70°C and the stretching ratio is 1.3 times. Example 3

[0040] A method for preparing a dual-core moisture-wicking functional fiber includes the following steps: S1. Prepare inner core spinning solution-1, outer core spinning solution and skin spinning solution respectively; S2. First, the inner core spinning solution-1 obtained in step S1 is wet-spun, cooled, stretched, and heat-set at 100°C to obtain the inner core fiber. The stretching temperature is 90°C and the stretching ratio is 4 times. The inner core fiber is passed through the annular spinneret of a single-screw extruder to cover the center of the die head. The outer core spinning solution obtained in step S1 is melt-extruded, cooled, stretched, and heat-set at 110°C to form the outer core layer and obtain the double core fiber. The stretching temperature is 70°C and the stretching ratio is 1.3 times. The double core fiber is introduced into the annular spinneret again to cover the center of the die head. The outer layer spinning solution obtained in step S1 is melt-extruded and uniformly coated on the surface of the double core fiber. After cooling, stretching, and heat-setting at 100°C, the double core moisture-wicking functional fiber is obtained. The stretching temperature is 80°C and the stretching ratio is 1.3 times. Example 4

[0041] A method for preparing a dual-core moisture-wicking functional fiber, the specific implementation method is the same as in Example 1, except that the inner core spinning solution-1 is replaced with inner core spinning solution-2. Example 5

[0042] A method for preparing a dual-core moisture-wicking functional fiber, the specific implementation method is the same as in Example 1, except that the inner core spinning solution-1 is replaced with inner core spinning solution-3.

[0043] Comparative Example 1 A method for preparing a moisture-wicking functional fiber includes the following steps: S1. Prepare the inner core spinning solution-1 and the outer layer spinning solution respectively; S2. First, the inner core spinning solution-1 obtained in step S1 is wet spun, cooled, stretched, and heat-set at 90°C to obtain the inner core fiber. The stretching temperature is 87°C and the stretching ratio is 4 times. The inner core fiber is introduced into the center of the annular spinneret head, and the sheath spinning solution obtained in step S1 is melted and extruded to uniformly coat the surface of the double core fiber. After cooling, stretching, and heat-setting at 97°C, the moisture-wicking functional fiber is obtained. The stretching temperature is 80°C and the stretching ratio is 1.3 times.

[0044] Performance testing The moisture-wicking properties of the moisture-wicking functional fibers obtained in the above embodiments and comparative examples were tested, and the test methods are shown in Table 1: Table 1 The test results are shown in Table 2: Table 2 As shown in Table 1, the fibers in Examples 1-3 of this invention have high moisture permeability and high wicking height, indicating that they have good moisture-wicking properties. The comparison between Example 4 and Example 1 shows that changing the ratio of polyvinyl alcohol and acrylic acid may result in an excessive amount of acrylic acid grafting in the core, leading to excessive hydrophilicity. After absorbing water, it is easy to form a dense water film, which in turn hinders the diffusion of water vapor molecules and reduces the moisture-wicking properties of the fiber. The comparison between Example 5 and Example 1 shows that the moisture-wicking properties of the fiber decrease when polyvinyl alcohol is not modified. The comparison between Comparative Example 1 and Example 1 shows that when the fiber only includes an inner core layer and a sheath layer, the moisture-wicking properties of the fiber are poor.

[0045] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a dual-core moisture-wicking functional fiber, comprising the following steps: S1. Prepare the inner core spinning solution, outer core spinning solution and skin spinning solution respectively; S2. First, the inner core spinning solution obtained in step S1 is wet-spun, cooled, stretched, and heat-set to obtain the inner core fiber. The inner core fiber is passed through the annular spinneret of a single-screw extruder to cover the center of the die head. The outer core spinning solution obtained in step S1 is melt-extruded, cooled, stretched, and heat-set to form an outer core layer to obtain a double core fiber. The double core fiber is introduced into the annular spinneret again to cover the center of the die head. The outer layer spinning solution obtained in step S1 is melt-extruded to uniformly cover the surface of the double core fiber. After cooling, stretching, and heat-setting, a double core moisture-wicking functional fiber is obtained.

2. The method for preparing the dual-core moisture-wicking functional fiber according to claim 1, characterized in that, The preparation method of the inner core spinning solution includes the following steps: adding modified polyvinyl alcohol, sodium alginate, nano silica, polyvinylpyrrolidone, and crosslinking agent to deionized water, stirring and dissolving at 90-100℃ to obtain the solution.

3. The method for preparing the dual-core moisture-wicking functional fiber according to claim 2, characterized in that, The mass ratio of the modified polyvinyl alcohol to sodium alginate is 1:(0.35-0.45).

4. The method for preparing the dual-core moisture-wicking functional fiber according to claim 2, characterized in that, The mass ratio of the modified polyvinyl alcohol to nano silica is 1:(0.025-0.035).

5. The method for preparing the dual-core moisture-wicking functional fiber according to claim 2, characterized in that, The mass ratio of the modified polyvinyl alcohol to polyvinylpyrrolidone is 1:(0.05-0.15).

6. The method for preparing the dual-core moisture-wicking functional fiber according to claim 2, characterized in that, The method for preparing the modified polyvinyl alcohol includes the following steps: adding polyvinyl alcohol to deionized water, heating to 90°C, stirring for 1-2 hours, cooling to 68-72°C, adding potassium persulfate and maintaining the temperature for 5-15 minutes to initiate the reaction, adding a mixture of acrylic acid and dodecyl mercaptan dropwise, continuing the reaction for 1-3 hours after the addition is complete, cooling to room temperature, precipitating in methanol, Soxhlet extraction, and vacuum drying to obtain the modified polyvinyl alcohol.

7. The method for preparing the dual-core moisture-wicking functional fiber according to claim 6, characterized in that, The mass ratio of polyvinyl alcohol to acrylic acid is 1:(0.05-0.15).

8. The method for preparing the dual-core moisture-wicking functional fiber according to claim 1, characterized in that, The preparation method of the outer core spinning solution includes the following steps: melting hydrophilic polyurethane at 150-170℃ to obtain the solution.

9. The method for preparing the dual-core moisture-wicking functional fiber according to claim 1, characterized in that, The preparation method of the skin spinning solution includes the following steps: melting hydrophobic polyurethane at 170-180℃ to obtain the solution.

10. The method for preparing the dual-core moisture-wicking functional fiber according to claim 1, characterized in that, The single-screw extruder operates at a speed of 30-60 rpm.

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