High-performance thermal core yarn and method for manufacturing the same

Abstract

The application discloses a kind of high-performance thermal core yarn and preparation method thereof, comprising the following steps: S1, using 1-allyl-3-methyl imidazole chlorine solution, degreasing cotton and sodium alginate preparation cellulose fiber spinning solution;S2, wet spinning is carried out to cellulose fiber spinning solution, and supercritical drying method is used to obtain cellulose porous structure fiber;S3, SEBS solution is introduced into cellulose porous structure fiber to obtain yarn by incomplete curing;S4, based on yarn and aramid short fiber compact siro spinning is spun to obtain core yarn.The beneficial effects of the application are: improve the thermal insulation and warmth of core yarn, and the core yarn also has softness and good mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of core-spun yarn technology, specifically to a high-performance thermal insulation core-spun yarn and its preparation method. Background Technology

[0002] Aramid, as a high-performance fiber, contains stable benzene rings and strong amide bonds in its molecular structure, exhibiting excellent heat resistance, chemical corrosion resistance, and high strength, and is widely used in bulletproof vests, fireproof clothing, and other fields. However, its inherent defects, such as poor softness and warmth retention, limit its application in thermal insulation.

[0003] In the prior art, patent CN112410965A discloses a method for preparing fluorescent flame-retardant and arc-resistant yarn. The addition of silicon-nitrogen flame-retardant adhesive improves the flame-retardant performance of the yarn to a certain extent, but it leads to uneven adhesive distribution between fibers, thus reducing the mechanical properties of the yarn. Patent CN103266376A discloses a flame-retardant core-spun yarn and its processing method. While coating glass fibers with aramid fibers can effectively improve the flame-retardant performance of the yarn, it also increases the yarn's hardness and rigidity, affecting the product's flexibility and service life. Porous fibers obtained through wet spinning have excellent warmth retention and heat insulation capabilities, but their high porosity also results in insufficient mechanical properties, leading to structural deformation and pore blockage, affecting their durability and long-term performance stability. There is a problem of not being able to simultaneously possess both softness and good mechanical properties. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application proposes a high-performance thermal insulation core-spun yarn and its preparation method, which improves the thermal insulation and warmth retention of the core-spun yarn, while also possessing softness and good mechanical properties.

[0005] The following is the technical solution of the present invention: a method for preparing high-performance thermal insulation core-spun yarn, comprising the following steps:

[0006] S1. A cellulose fiber spinning solution was prepared using 1-allyl-3-methylimidazolium chloride solution, defatted cotton, and sodium alginate.

[0007] S2. The cellulose fiber spinning solution is wet-spun, and porous cellulose fibers are obtained by supercritical drying.

[0008] S3. Porous cellulose fibers are partially cured by passing them through a SEBS solution to obtain yarn.

[0009] S4. Core-spun yarn is obtained by compact Siro spinning of yarn and aramid staple fiber.

[0010] Preferably, in S1, the mass concentration of the 1-allyl-3-methylimidazolium chloride solution is 25-30 wt%, the cellulose content of the degreased cotton is 95%, the degree of degreasing is ≥98%, the purity of sodium alginate is ≥99%, and the viscosity is 200-500 mPa·s.

[0011] Preferably, in S2, the coagulation bath for wet spinning is an aqueous solution, the spinning speed is 20-30 ml / h, and the soaking time in the coagulation bath is 8-10 h.

[0012] Preferably, in S2, the supercritical fluid in the supercritical drying method is carbon dioxide, the pressure is 10-35 MPa, the flow rate is 600-1000 ml / h, the treatment time is 1-2.5 h, and the decompression rate is 0.6-6 MPa / h.

[0013] Preferably, in S3, the mass concentration of the SEBS solution is 8 wt%, the solvent is isopropanol, and the mass of the porous cellulose fiber is 2-5 times that of the SEBS solution.

[0014] Preferably, in S3, incomplete curing is performed by a first heating curing device, which is either an electric heating curing device or a first electron beam heating curing device.

[0015] When using an electric heating curing device, heat the porous cellulose fibers to 120-150℃ for 8-12 minutes to achieve a 90% curing degree of the SEBS solution on the surface of the porous cellulose fibers.

[0016] When using the first electron beam heating curing device, irradiation at 150-200keV for 10-12 seconds is performed to achieve a curing degree of 80% on the surface of the porous cellulose fiber of the SEBS solution.

[0017] Preferably, in S4, compact Siro spinning is performed by a twisting device and spinning is performed by a spinning ring. A second heating and curing device is provided between the twisting device and the spinning ring. The second heating and curing device is a second electron beam heating and curing device or an infrared heating and curing device.

[0018] A high-performance thermal core-spun yarn includes: cellulose porous structure fiber, the surface of the cellulose porous fiber is cured with SEBS coating, and aramid short fibers are twisted onto the SEBS coating surface.

[0019] Preferably, the average length of the aramid staple fiber is 20-170 mm.

[0020] Preferably, the cross-sectional area of ​​the SEBS coating is smaller than that of the porous cellulose fiber.

[0021] The beneficial effects of this invention are:

[0022] 1. Using porous cellulose fibers as the core layer and aramid short fibers as the sheath layer, the core-spun yarn prepared not only has good mechanical properties such as high strength and abrasion resistance, but also excellent heat retention properties. The porosity of the porous cellulose fibers can provide good heat retention, while the aramid short fibers enhance the durability and stability of the yarn.

[0023] 2. Carbon dioxide has properties that are both like a gas and a liquid. In the supercritical state, it can penetrate the inside of the fiber and dissolve the solvent inside without causing the pore structure to collapse due to surface tension. Using supercritical drying to dry porous cellulose fibers can preserve the porous structure in the fiber to a large extent, ensuring the warmth and heat insulation of the core-spun yarn. Attached Figure Description

[0024] Figure 1 This is a flowchart of the preparation method of the core-spun yarn of the present invention;

[0025] Figure 2 This is a schematic diagram of the preparation process of the core-spun yarn of the present invention;

[0026] Figure 3 This is a cross-sectional structural diagram of the core-spun yarn of the present invention;

[0027] In the figure: 1. SEBS coating; 2. Aramid short fiber; 3. Cellulose porous structure fiber; 4. Core-spun yarn; 5. SEBS solution; 11. First heating and curing device; 12. Second heating and curing device; 13. Twisting device. Detailed Implementation

[0028] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1:

[0030] like Figure 1 and Figure 2 As shown, a method for preparing a high-performance thermal insulation core-spun yarn includes the following steps:

[0031] S1. A cellulose fiber spinning solution was prepared using 1-allyl-3-methylimidazolium chloride solution, defatted cotton, and sodium alginate.

[0032] S2. The cellulose fiber spinning solution is wet-spun, and the porous cellulose fiber is obtained by supercritical drying.

[0033] S3. The porous cellulose fiber 3 is partially cured by passing SEBS solution 5 to obtain yarn.

[0034] S4. Core-spun yarn 4 is obtained by compact Siro spinning based on yarn and aramid staple fiber 2.

[0035] In step S1, a cellulose fiber spinning solution is prepared using 1-allyl-3-methylimidazolium chloride solution, degreased cotton, and sodium alginate. The degreased cotton has a cellulose content of 95% and a degreasing degree of ≥98%, while the sodium alginate has a purity of ≥99% and a viscosity of 200-500 mPa·s.

[0036] 5 wt% defatted cotton and 3 wt% sodium alginate were dissolved in a 30% 1-allyl-3-methylimidazolium chloride solution. The solution was stirred for 2 hours at a dissolution temperature of 60°C and a stirring speed of 500 rpm to obtain a uniform cellulose fiber spinning solution.

[0037] In step S2, the cellulose fiber spinning solution is wet-spun, and the porous cellulose fiber 3 is obtained by supercritical drying.

[0038] During wet spinning, a pressure pump and a 0.35mm needle are used to squeeze the spinning solution into the aqueous coagulation bath at a rate of 25ml / h, and the solution is soaked for 10h.

[0039] When drying solid fibers using the supercritical drying method, 500m of solid fiber is taken out from the coagulation bath, wound up and implanted into a supercritical dryer. Carbon dioxide is used as the supercritical fluid, the pressure is set to 30MPa and the flow rate is 800ml / h. After treatment for 2.5h, the decompression rate is set to 6MPa / h and the pressure is reduced for 5h to obtain porous cellulose fiber 3.

[0040] In step S3, the porous cellulose fiber 3 is passed through SEBS solution 5 for incomplete curing to obtain yarn.

[0041] 3500m of porous cellulose fiber 3 was immersed in an 8wt% SEBS solution 5 at 40°C for 2 hours. The porous cellulose fiber 3 was then removed from the SEBS solution 5 and heated to 125°C for 8 minutes using an electric heating method, allowing the SEBS solution 5 to solidify to approximately 90% on the surface of the porous cellulose fiber 3, resulting in yarn.

[0042] The SEBS solution 5 on the surface of the porous cellulose fiber 3 is partially heated and cured by the first heating and curing device 11, which can be an electric heating and curing device or a first electron beam heating and curing device.

[0043] When using an electric heating curing device for electric heating curing, the porous cellulose fiber 3 is heated to 120-150℃ for 8-12 minutes, so that the SEBS solution 5 is cured to 90% on the surface of the porous cellulose fiber 3; when using a first electron beam heating curing device for electron beam heating curing, it is irradiated with 150-200keV for 10-12 seconds, so that the SEBS solution 5 is cured to 80% on the surface of the porous cellulose fiber 3.

[0044] SEBS solution 5 has a mass concentration of 8 wt%, isopropanol is the solvent, and the mass of cellulose porous fiber 3 is 2-5 times that of SEBS solution 5.

[0045] In step S4, core-spun yarn 4 is obtained by compact Siro spinning based on yarn and aramid staple fiber 2.

[0046] Using yarn as the core fiber and aramid short fiber 2 as the sheath fiber, core-spun yarn 4 is obtained by compact Sirospun spinning.

[0047] Compact Siro spinning is performed using a twisting device 13, and spinning is carried out through a spinning ring. The yarn between the twisting device 13 and the spinning ring is then cured. During Siro spinning, a second heating and curing device 12 is provided between the twisting device 13 and the spinning ring. The second heating and curing device 12 can be a second electron beam heating and curing device or an infrared heating and curing device.

[0048] When using the second electron beam heating device, irradiation at 200keV completely solidifies the SEBS solution 5 in the yarn and evaporates the remaining solution in the yarn.

[0049] Example 2:

[0050] like Figure 3 As shown, a high-performance thermal core-spun yarn includes: cellulose porous fiber 3, the surface of cellulose porous fiber 3 is cured with SEBS coating 1, and aramid short fiber 2 is twisted onto the surface of SEBS coating 1.

[0051] The average length of aramid staple fiber 2 is 20-170 mm.

[0052] The cross-sectional area of ​​SEBS coating 1 is smaller than that of porous cellulose fiber 3.

[0053] SEBS coating 1 is formed by curing SEBS solution 5 on the surface of cellulose porous fiber 3. The mass concentration of SEBS solution 5 is 8 wt%, the solvent is isopropanol, and the mass of cellulose porous fiber 3 is 2-5 times that of SEBS solution 5.

[0054] Comparative Example 1:

[0055] Unlike Example 1, the core fiber of Comparative Example 1 is not treated with SEBS coating.

[0056] Preparation of cellulose fiber spinning solution: 5 wt% degreased cotton and 3 wt% sodium alginate were dissolved in a 30% 1-allyl-3-methylimidazolium chloride solution. The solution was stirred for 2 hours at a dissolution temperature of 60℃ and a stirring speed of 500 rpm to obtain a uniform cellulose fiber spinning solution.

[0057] Preparation of porous cellulose fiber 3: The spinning solution was extruded into a water coagulation bath at a rate of 25 ml / h using a pressure pump and a 0.35 mm needle, and soaked for 10 h. 500 m of solid fiber was taken out from the coagulation bath, wound up, and implanted into a supercritical dryer. Carbon dioxide was used as the supercritical fluid, the pressure was set at 30 MPa, the flow rate at 800 ml / h, and the treatment was carried out for 2.5 h. Then, the decompression rate was set at 6 MPa / h, and the pressure was reduced for 5 h to obtain porous cellulose fiber 3.

[0058] Preparation of core-spun yarn 4: Core-spun yarn 4 is obtained by using cellulose porous fiber 3 as the core fiber and aramid short fiber 2 as the sheath fiber through compact Sirospun spinning.

[0059] Comparative Example 2:

[0060] Unlike Example 1, Comparative Example 2 does not perform stepwise curing of SEBS solution 5.

[0061] Preparation of cellulose fiber spinning solution: 5 wt% degreased cotton and 3 wt% sodium alginate were dissolved in a 30% 1-allyl-3-methylimidazolium chloride solution. The solution was stirred for 2 hours at a dissolution temperature of 60℃ and a stirring speed of 500 rpm to obtain a uniform cellulose fiber spinning solution.

[0062] Preparation of porous cellulose fiber 3: The spinning solution was extruded into a water coagulation bath at a rate of 25 ml / h using a pressure pump and a 0.35 mm needle, and soaked for 10 h. 500 m of solid fiber was taken out from the coagulation bath, wound up, and implanted into a supercritical dryer. Carbon dioxide was used as the supercritical fluid, the pressure was set at 30 MPa, the flow rate at 800 ml / h, and the treatment was carried out for 2.5 h. Then, the decompression rate was set at 6 MPa / h, and the pressure was reduced for 5 h to obtain porous cellulose fiber 3.

[0063] Yarn preparation: 3500m of porous cellulose fibers were impregnated in an 8wt% SEBS solution 5 at 40℃ for 2 hours. The fibers were then removed from the SEBS solution 5 and heated to 125℃ using an electric heating method for 8 minutes, until the SEBS solution 5 was approximately 99% cured on the fiber surface, thus obtaining the yarn.

[0064] Preparation of core-spun yarn 4: Using yarn as the core fiber and aramid short fiber 2 as the sheath fiber, core-spun yarn 4 is obtained by compact Sirospun spinning.

[0065] Comparative Example 3:

[0066] Unlike Example 1, Comparative Example 3 uses glass fiber as the core fiber.

[0067] Preparation of glass fiber core-spun yarn 4: Using glass fiber as the core fiber and aramid staple fiber as the sheath fiber, core-spun yarn 4 is obtained by compact Sirospun spinning.

[0068] The performance of the core-spun yarn 4 of Example 1 and Comparative Examples 1 to 3 of the present invention was tested, and the test parameters included tensile strength, elongation at break and thermal conductivity.

[0069] Tensile strength testing was conducted according to GB / T1040.3-2006, "Determination of Tensile Properties of Plastics - Part 3: Films and Sheets." Standard-shaped and sized specimens were prepared within the battery separator, ensuring the testing environment met the standard requirements. The specimens were placed on a tensile testing machine, and tensile force was applied at a specified rate. Strain data under different stresses were recorded until the specimen fractured. The tensile strength was calculated based on the maximum force and original cross-sectional area experienced by the specimen before fracture.

[0070] The elongation at break was tested according to DB51 / T1916.6-2014 "Test Methods for Aramid III Fibers Part 6: Breaking Strength, Elongation at Break and Modulus". A 350mm long untwisted bundle (if the bundle (strand) of the multifilament is twisted, it needs to be naturally detwisted under suspension) was cut and prepared by standard twisting on a twisting machine. The twist degree was calculated according to the following formula:

[0071]

[0072] In the above formula, TMP is the twist degree, with the unit being twist per meter (T / m); T is the measured linear density, with the unit being tex (tex).

[0073] During testing, the sample wire is placed on the tensile testing machine, ensuring that the wire is axially straight and clamped between two fixtures, and a pre-tension is applied. The tensile testing machine is run, and the breaking strength and elongation at break are read directly, and the load-elongation curve is recorded.

[0074] The thermal conductivity was tested according to GB / T 5990-2021 "Test Methods for Thermal Conductivity, Specific Heat Capacity and Thermal Diffusion Coefficient of Refractory Materials (Hot Wire Method)". The yarns prepared in Example 1 and Comparative Examples 1 to 3 were made into 230 g / m² plain knitted fabrics. These fabrics were heated in an oven to a specified temperature and held at that temperature. Local heating was performed using a linear electrical conductor (hot wire) embedded along the length of the sample. The hot wire carried a current of known constant power, meaning the power remained constant over time and along the sample length. The thermal conductivity could be calculated from the power of the hot wire and the temperature at two known time intervals after heating with the current. This temperature rise as a function of time is the thermal conductivity of the tested sample.

[0075] The performance test results of the core-spun yarn 4 prepared in Example 1 and Comparative Examples 1 to 3 are shown in Table 1:

[0076] Table 1:

[0077]

[0078] Based on the data in Table 1, compared to Comparative Example 1, Example 1 exhibits a significant decrease in tensile strength and elongation at break, and a marked increase in thermal conductivity. This is because the core fiber used in Example 1 is coated with SEBS. In the physical structure of SEBS, the hard styrene segments provide rigidity, while the soft ethylene-butene segments impart elasticity and toughness to the material. The SEBS coating on the fiber surface not only provides external mechanical support but also enhances the fiber's resilience under tension, thus improving its tensile elasticity. Simultaneously, SEBS, as a thermoplastic elastomer, has a lower thermal conductivity relative to the fiber itself. When SEBS is coated on the fiber, it acts not only as a mechanical reinforcing material but also as a thermal insulation layer, reducing heat transfer through the fiber.

[0079] Compared to Comparative Example 2, Example 1 employed a step-by-step curing process for the SEBS coating 1. In this process, the SEBS coating 1 was first pre-cured under milder conditions. This stage primarily involved surface and shallower layers of the coating, aiming to form a stable interface. A deeper, more thorough curing process was then performed in the subsequent spinning process, increasing the tightness between the core yarn and the cover yarn. In contrast, in a one-step curing process, the SEBS coating 1 completed the entire curing process under fixed conditions. While this method is simple and fast, it may lead to uneven curing. Furthermore, compared to the step-by-step curing process, the tightness between the core yarn and the cover yarn is poorer, thus reducing the mechanical properties of the product.

[0080] Compared to Example 1, the core-spun yarn 4 in Comparative Example 3 uses glass fiber as the core yarn. This material has a very uniform and stable structure at the microscopic level and possesses high tensile strength. Although glass fiber has high rigidity, it has low toughness and is prone to breakage rather than bending. This characteristic stems from the brittleness of glass fiber. At the same time, glass fiber has relatively high thermal conductivity, which makes it perform well in thermal management applications, but it may not be the best choice for applications requiring thermal insulation.

[0081] This invention uses porous cellulose fiber 3 as the core layer and aramid short fiber 2 as the sheath layer to prepare core-spun yarn 4. The resulting yarn not only possesses excellent mechanical properties such as high strength and abrasion resistance, but also superior thermal insulation performance. The porosity of the porous cellulose fiber 3 provides good thermal insulation, while the aramid short fiber 2 enhances the yarn's durability and stability, making it suitable for thermal insulation applications in low-temperature environments, such as the manufacture of winter clothing and outdoor equipment. Carbon dioxide has properties that are both gaseous and liquid; in a supercritical state, it can penetrate the fiber interior and dissolve the solvent without causing the pore structure to collapse due to surface tension. Using supercritical drying to dry the porous cellulose fiber 3 can largely preserve the porous structure within the fiber, ensuring the thermal insulation and heat insulation capabilities of the core-spun yarn 4.

[0082] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0083] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a high-performance thermal insulation core-spun yarn, characterized in that, Includes the following steps: S1. A cellulose fiber spinning solution was prepared using 1-allyl-3-methylimidazolium chloride solution, defatted cotton, and sodium alginate. S2. The cellulose fiber spinning solution is wet-spun, and porous cellulose fibers are obtained by supercritical drying. The coagulation bath for wet spinning is an aqueous solution, the spinning speed is 20-30 ml / h, and the soaking time in the coagulation bath is 8-10 h. The supercritical fluid used in the supercritical drying method is carbon dioxide, with a pressure of 10-35 MPa, a flow rate of 600-1000 ml / h, a treatment time of 1-2.5 h, and a decompression rate of 0.6-6 MPa / h. S3. Porous cellulose fibers are partially cured by passing them through a SEBS solution to obtain yarn. The SEBS solution has a mass concentration of 8 wt%, the solvent is isopropanol, and the mass of the porous cellulose fiber is 2-5 times that of the SEBS solution. Incomplete curing is performed using a first heating and curing device, which is either an electric heating and curing device or a first electron beam heating and curing device. When using an electric heating curing device, heat the porous cellulose fibers to 120-150℃ for 8-12 minutes to achieve a 90% curing degree of the SEBS solution on the surface of the porous cellulose fibers. When using the first electron beam heating curing device, irradiation at 150-200 keV for 10-12 seconds is applied to achieve a curing degree of 80% on the surface of the porous cellulose fiber of the SEBS solution; S4. Core-spun yarn is obtained by compact Siro spinning of yarn and aramid staple fiber.

2. The method for preparing a high-performance thermal insulation core-spun yarn according to claim 1, characterized in that, In S1, the mass concentration of 1-allyl-3-methylimidazolium chloride solution is 25-30 wt%, the cellulose content of the degreased cotton is 95%, the degree of degreasing is ≥98%, the purity of sodium alginate is ≥99%, and the viscosity is 200-500 mPa·s.

3. The method for preparing a high-performance thermal insulation core-spun yarn according to claim 1, characterized in that, In S4, compact Siro spinning is performed by a twisting device and spinning is performed by a spinning ring. A second heating and curing device is provided between the twisting device and the spinning ring. The second heating and curing device is a second electron beam heating and curing device or an infrared heating and curing device.

4. A high-performance thermal insulation core-spun yarn, applicable to the preparation method of the high-performance thermal insulation core-spun yarn as described in any one of claims 1-3, characterized in that, include: Cellulose porous fiber, the surface of which is cured with SEBS coating, and aramid short fibers are twisted onto the SEBS coating surface.

5. The high-performance thermal insulation core-spun yarn according to claim 4, characterized in that, The average length of aramid staple fiber is 20-170 mm.

6. The high-performance thermal insulation core-spun yarn according to claim 4, characterized in that, The cross-sectional area of ​​the SEBS coating is smaller than that of the porous cellulose fiber.

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