High-performance warm-keeping covering yarn and preparation method thereof

Abstract

The invention discloses a high-performance warm-keeping core-spun yarn and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a cellulose fiber spinning solution from a 1-allyl-3-methylimidazole chloride solution, absorbent cotton and sodium alginate; s2, performing wet spinning on the cellulose fiber spinning solution, and obtaining cellulose porous structure fibers by adopting a supercritical drying method; s3, introducing an SEBS solution into the cellulose porous structure fibers, and carrying out incomplete curing to obtain yarns; s4, performing compact siro spinning on the basis of the yarns and the aramid short fibers to obtain the core-spun yarns. The core-spun yarn has the beneficial effects that the heat insulation property and the heat retention property of the core-spun yarn are improved, and meanwhile, the core-spun yarn also has softness and good mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of core-spun yarns, and in particular to a high-performance warm-keeping core-spun yarn and a preparation method thereof. Background Art

[0002] As a high-performance fiber, aramid contains stable benzene rings and strong amide bonds in its molecular structure. It has excellent heat resistance, chemical corrosion resistance and high strength, and is widely used in bulletproof vests, fireproof clothing and other fields. However, due to its own defects, such as poor softness and warmth retention, its application in the field of thermal insulation is limited.

[0003] In the prior art, patent CN112410965A discloses a method for preparing fluorescent flame-retardant arc-proof yarn. The addition of silicon-nitrogen flame-retardant viscose improves the flame retardant properties of the yarn to a certain extent, but it will cause the viscose between fibers to be uneven and reduce the mechanical properties of the yarn. Patent CN103266376A discloses a flame-retardant core-spun yarn and processing method. Although the method of coating aramid fiber with glass fiber can effectively improve the flame retardant properties of the yarn, it will also increase the hardness and rigidity of the yarn, affecting the flexibility and service life of the product. The porous structure fiber obtained by wet spinning has excellent warmth retention and heat insulation capabilities, but the high porosity also causes the disadvantage of insufficient mechanical properties, and structural deformation, pore clogging and other phenomena will occur, affecting its durability and long-term performance stability. There is a problem that it cannot have both softness and good mechanical properties. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present application proposes a high-performance thermal insulation core-spun yarn and a preparation method thereof, which improve the thermal insulation and warmth retention of the core-spun yarn. At the same time, the core-spun yarn also has softness and good mechanical properties.

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

[0006] S1, preparing a cellulose fiber spinning solution using 1-allyl-3-methylimidazolium chloride solution, absorbent cotton and sodium alginate;

[0007] S2, wet spinning the cellulose fiber spinning solution, and obtaining cellulose porous structure fibers by supercritical drying method;

[0008] S3, passing SEBS solution into the cellulose porous structure fiber for incomplete curing to obtain yarn;

[0009] S4, core-spun yarn is obtained by compact siro spinning of yarn and aramid staple fibers.

[0010] Preferably, in S1, the mass concentration of 1-allyl-3-methylimidazolium chloride solution is 25-30wt%, the cellulose content of the absorbent cotton is 95%, the degreasing degree is ≥98%, the purity of sodium alginate is ≥99%, and the viscosity is 200-500mPa·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 immersion time in the coagulation bath is 8-10 h.

[0012] Preferably, in S2, the supercritical fluid of the supercritical drying method is carbon dioxide, the pressure is 10-35 MPa, the flow rate is 600-1000 ml / h, the processing 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 cellulose porous structure fibers is 2-5 times that of the SEBS solution.

[0014] Preferably, in S3, incomplete curing is performed by a first heating and curing device, and the first heating and curing device is an electric heating and curing device or a first electron beam heating and curing device;

[0015] When using an electric heating curing device, the cellulose porous structure fiber is heated to 120-150° C. for 8-12 minutes, so that the degree of curing of the SEBS solution on the surface of the cellulose porous structure fiber reaches 90%;

[0016] When the first electron beam heating curing device is used, 150-200 keV is irradiated for 10-12 seconds, so that the curing degree of the SEBS solution on the surface of the cellulose porous structure fiber reaches 80%.

[0017] Preferably, in S4, compact siro spinning is performed by a twisting device, and spinning is performed by a spinning ring, and a second heating and curing device is provided between the twisting device and the spinning ring, and 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 insulation core-spun yarn comprises: a cellulose porous structure fiber, a SEBS coating is cured on the surface of the cellulose porous structure fiber, and aramid staple fibers are twisted and spun on the surface of the SEBS coating.

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

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

[0021] The beneficial effects of the present invention are:

[0022] 1. The core-spun yarn prepared by using cellulose porous structure fiber as the core layer and aramid staple fiber as the skin layer not only has good mechanical properties such as high strength and wear resistance, but also has excellent thermal insulation performance. The porosity of cellulose porous structure fiber can provide good thermal insulation effect, and aramid staple fiber enhances the durability and stability of the yarn;

[0023] 2. Carbon dioxide has the properties of being both gas and liquid. Under the supercritical state, it can penetrate the interior of the fiber and dissolve the solvent therein without causing the collapse of the pore structure due to surface tension. Using the supercritical drying method to dry the cellulose porous structure fiber can retain the porous structure in the fiber to a large extent, thus ensuring the warmth retention and heat insulation capabilities of the core-spun yarn. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flow chart of the method for preparing the core-spun yarn;

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

[0026] Figure 3 It is a schematic cross-sectional structure diagram of the core-spun yarn of the present invention;

[0027] In the figure: 1. SEBS coating; 2. Aramid staple 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 DESCRIPTION

[0028] In order 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 in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1:

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

[0031] S1, preparing a cellulose fiber spinning solution using 1-allyl-3-methylimidazolium chloride solution, absorbent cotton and sodium alginate;

[0032] S2, wet spinning the cellulose fiber spinning solution, and obtaining cellulose porous structure fiber 3 by supercritical drying method;

[0033] S3, passing SEBS solution 5 into the cellulose porous structure fiber 3 for incomplete curing to obtain yarn;

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

[0035] In step S1, 1-allyl-3-methylimidazolium chloride solution, absorbent cotton and sodium alginate are used to prepare cellulose fiber spinning solution, wherein the cellulose content of the absorbent cotton is 95%, the degreasing degree is ≥98%, the purity of the sodium alginate is ≥99%, and the viscosity is 200-500 mPa·s.

[0036] 5wt% of absorbent cotton and 3wt% of sodium alginate were dissolved in a 1-allyl-3-methylimidazolium chloride solution with a mass concentration of 30%, and stirred for 2 hours at a dissolving 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 cellulose porous structure fiber 3 is obtained by supercritical drying.

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

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

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

[0041] The cellulose porous structural fiber 3500m was immersed in a SEBS solution 5 with a mass concentration of 8wt%, the temperature was 40°C, and the treatment time was 2h. The cellulose porous structural fiber 3 was taken out from the SEBS solution 5, and the cellulose porous structural fiber 3 was heated to 125°C by an electric heating method for 8 minutes, so that the curing degree of the SEBS solution 5 on the surface of the cellulose porous structural fiber 3 reached about 90%, and the yarn was obtained.

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

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

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

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

[0046] The yarn is used as the core fiber and the aramid staple fiber 2 is used as the sheath fiber, and the core-spun yarn 4 is obtained by compact siro spinning.

[0047] The twisting device 13 is used to perform compact siro spinning, and the spinning is performed through the spinning ring, and the yarn between the twisting device 13 and the spinning ring is solidified. During siro spinning, a second heating and curing device 12 is arranged between the twisting device 13 and the spinning ring, and 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 the second electron beam heating device is used, 200 keV is irradiated to completely cure the SEBS solution 5 in the yarn and evaporate the residual solution in the yarn.

[0049] Embodiment 2:

[0050] like Figure 3 As shown, a high-performance thermal insulation core-spun yarn includes: a cellulose porous structure fiber 3, a SEBS coating 1 cured on the surface of the cellulose porous structure fiber 3, and aramid staple fibers 2 twisted and spun on the surface of the SEBS coating 1.

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

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

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

[0054] Comparative Example 1:

[0055] Different from Example 1, the core layer fiber of Comparative Example 1 is not coated with SEBS.

[0056] Preparation of cellulose fiber spinning solution: 5wt% of cotton wool and 3wt% of sodium alginate were dissolved in a 30% mass concentration of 1-allyl-3-methylimidazolium chloride solution, and stirred for 2 hours at a dissolving temperature of 60°C and a stirring speed of 500 rpm to obtain a uniform cellulose fiber spinning solution.

[0057] Preparation of cellulose porous structural fiber 3: Use a pressure pump and a 0.35 mm needle to squeeze the spinning solution into a water coagulation bath at a rate of 25 ml / h and soak for 10 hours. Take out 500 m of solid fiber from the coagulation bath, wind it up and implant it into a supercritical dryer, use carbon dioxide as the supercritical fluid, set the pressure to 30 MPa, and the flow rate to 800 ml / h. After treating for 2.5 hours, set the decompression rate to 6 MPa / h and reduce the pressure for 5 hours to obtain cellulose porous structural fiber 3.

[0058] Preparation of core-spun yarn 4: Using cellulose porous structure fiber 3 as core fiber and aramid staple fiber 2 as sheath fiber, the core-spun yarn 4 is obtained by compact siro spinning.

[0059] Comparative Example 2:

[0060] Different from Example 1, in Comparative Example 2, the SEBS solution 5 is not subjected to step-by-step curing treatment.

[0061] Preparation of cellulose fiber spinning solution: 5wt% of cotton wool and 3wt% of sodium alginate were dissolved in a 30% mass concentration of 1-allyl-3-methylimidazolium chloride solution, and stirred for 2 hours at a dissolving temperature of 60°C and a stirring speed of 500 rpm to obtain a uniform cellulose fiber spinning solution.

[0062] Preparation of cellulose porous structural fiber 3: Use a pressure pump and a 0.35 mm needle to squeeze the spinning solution into a water coagulation bath at a rate of 25 ml / h and soak for 10 hours. Take out 500 m of solid fiber from the coagulation bath, wind it up and implant it into a supercritical dryer, use carbon dioxide as the supercritical fluid, set the pressure to 30 MPa, and the flow rate to 800 ml / h. After treating for 2.5 hours, set the decompression rate to 6 MPa / h and reduce the pressure for 5 hours to obtain cellulose porous structural fiber 3.

[0063] Preparation of yarn: 3500 m of cellulose porous structure fiber was immersed in SEBS solution 5 with a mass concentration of 8 wt% at a temperature of 40°C for 2 h. The fiber was taken out of SEBS solution 5 and heated to 125°C by electric heating for 8 minutes, so that the curing degree of SEBS solution 5 on the fiber surface reached about 99%, thereby obtaining yarn.

[0064] Preparation of core-spun yarn 4: yarn is used as core fiber and aramid staple fiber 2 is used as sheath fiber, and core-spun yarn 4 is obtained by compact siro spinning.

[0065] Comparative Example 3:

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

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

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

[0069] The tensile strength test refers to GB / T1040.3-2006 "Determination of tensile properties of plastics Part 3: Film and sheet". Prepare specimens of standard shape and size in the battery separator, and ensure that the test environment meets the standard requirements. Install the specimen on the tensile testing machine, apply tensile force to the specimen at a specified rate, and record the strain data of the specimen under different stresses until the specimen breaks. Calculate the tensile strength based on the maximum force and original cross-sectional area before the specimen breaks.

[0070] The test of elongation at break refers to DB51 / T1916.6-2014 "Test Methods for Aramid III Fibers Part 6: Breaking Strength, Elongation at Break and Modulus". Cut a 350mm long untwisted bundle (strand) of yarn (if the bundle (strand) of the multifilament has twist, it needs to be suspended and naturally twisted), and perform standard twisting on the twisting machine to make samples. The twisting twist is calculated according to the following formula:

[0071]

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

[0073] During the test, place the sample wire on the tensile machine, ensure that the sample wire is straightened along the axial direction and clamped between the two clamps, and apply pre-tension. Run the tensile tester, directly read the breaking strength and breaking elongation, and record the load-elongation curve.

[0074] The test of thermal conductivity refers to GB / T 5990-2021 "Test method for thermal conductivity, specific heat and thermal diffusion coefficient of refractory materials (hot wire method)". The yarns prepared in Example 1 and Comparative Examples 1 to 3 are prepared into 230g / m2 weft plain knitted fabrics, heated to a specified temperature in a furnace and kept warm at this temperature, and locally heated with a linear conductor (hot wire) buried in the sample along the length of the sample. The hot wire carries a current of known constant power, that is, the power is constant in time and in the length direction of the sample. The thermal conductivity can be calculated from the power of the hot wire and the temperature of two known time intervals after the current is turned on for heating. The function of this temperature rise and time is the thermal conductivity of the sample being tested.

[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] Comprehensively looking at the data in Table 1, compared with Comparative Example 1, Example 1 shows a significant decrease in tensile strength and elongation at break, as well as a significant 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 block segment provides rigidity, while the soft ethylene-butylene block segment gives the material elasticity and toughness. The SEBS coated on the fiber surface can not only provide external mechanical support, but also enable the fiber surface to have better recovery ability when stretched, which enhances the tensile elasticity of the fiber; at the same time, SEBS, as a thermoplastic elastomer, has a lower thermal conductivity than the fiber itself. When SEBS is coated on the fiber, it not only acts as a mechanical reinforcement material, but also acts as a thermal insulation layer to reduce the transfer of heat through the fiber.

[0079] Compared with Comparative Example 2, Example 1 adopts a step-by-step curing treatment for the SEBS coating 1. In the step-by-step curing treatment, the SEBS coating 1 is first pre-cured under mild conditions. This stage mainly cures the surface and shallow layers of the coating to form a stable interface, and then a deeper and thorough curing is performed in the subsequent spinning process to increase the compactness of the core yarn and the covering yarn. In the one-step curing treatment, the SEBS coating 1 completes the entire curing process under a fixed curing condition. Although this method is simple and fast, it may lead to uneven curing. At the same time, compared with the step-by-step curing treatment, the compactness between the core yarn and the covering yarn will be poor, thereby reducing the mechanical properties of the product.

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

[0081] The present invention adopts cellulose porous structure fiber 3 as the core layer and aramid staple fiber 2 as the sheath layer. The prepared core-spun yarn 4 not only has good mechanical properties such as high strength and wear resistance, but also has excellent thermal insulation performance. The porosity of cellulose porous structure fiber 3 can provide good thermal insulation effect, and aramid staple fiber 2 enhances the durability and stability of the yarn, which is suitable for thermal insulation applications in low temperature environments, such as making winter clothing and outdoor equipment; carbon dioxide has the characteristics of both gas and liquid. Under the supercritical state, it can penetrate the interior of the fiber to dissolve the solvent therein without causing the collapse of the pore structure due to surface tension. Using the supercritical drying method to dry the cellulose porous structure fiber 3 can retain the porous structure in the fiber to a large extent, thereby ensuring the thermal insulation and heat insulation capabilities of the core-spun yarn 4.

[0082] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0083] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a high-performance thermal insulation core-spun yarn, characterized in that: The following steps are involved: S1, preparing a cellulose fiber spinning solution using 1-allyl-3-methylimidazolium chloride solution, absorbent cotton and sodium alginate; S2, wet spinning the cellulose fiber spinning solution, and obtaining cellulose porous structure fibers by supercritical drying method; S3, passing SEBS solution into the cellulose porous structure fiber for incomplete curing to obtain yarn; S4, core-spun yarn is obtained by compact siro spinning of yarn and aramid staple fibers.

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 25-30wt%, the cellulose content of the absorbent cotton is 95%, the degreasing degree is ≥98%, the purity of sodium alginate is ≥99%, and the viscosity is 200-500mPa·s.

3. The method for preparing a high-performance thermal insulation core-spun yarn according to claim 1, characterized in that: In S2, the coagulation bath of wet spinning is an aqueous solution, the spinning speed is 20-30 ml / h, and the immersion time in the coagulation bath is 8-10 h.

4. A method for preparing a high-performance thermal insulation core-spun yarn according to claim 1 or 3, characterized in that: In S2, the supercritical fluid of the supercritical drying method is carbon dioxide, the pressure is 10-35MPa, the flow rate is 600-1000ml / h, the processing time is 1-2.5h, and the decompression rate is 0.6-6MPa / h.

5. The method for preparing a high-performance thermal insulation core-spun yarn according to claim 1, characterized in that: In S3, the mass concentration of the SEBS solution is 8 wt %, the solvent is isopropanol, and the mass of the cellulose porous structure fiber is 2-5 times that of the SEBS solution.

6. The method for preparing a high-performance thermal insulation core-spun yarn according to claim 1, characterized in that: In S3, incomplete curing is performed by a first heating and curing device, and the first heating and curing device is an electric heating and curing device or a first electron beam heating and curing device; When using an electric heating curing device, the cellulose porous structure fiber is heated to 120-150° C. for 8-12 minutes, so that the degree of curing of the SEBS solution on the surface of the cellulose porous structure fiber reaches 90%; When the first electron beam heating curing device is used, 150-200 keV is irradiated for 10-12 seconds, so that the curing degree of the SEBS solution on the surface of the cellulose porous structure fiber reaches 80%.

7. 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.

8. A high-performance thermal insulation core-spun yarn, suitable for the preparation method of a high-performance thermal insulation core-spun yarn as claimed in any one of claims 1 to 7, characterized in that: include: The porous cellulose structure fiber has a SEBS coating cured on its surface, and the surface of the SEBS coating has aramid staple fibers twisted on it.

9. A high-performance thermal insulation core-spun yarn according to claim 8, characterized in that: The average length of aramid staple fibers is 20-170 mm.

10. A high-performance thermal insulation core-spun yarn according to claim 8, characterized in that: The cross-sectional area of ​​the SEBS coating is smaller than that of the cellulose porous structure fibers.

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