Preparation method of high-elasticity skin-friendly impact-resistant intelligent yarn and intelligent yarn

Abstract

A method for preparing a highly elastic, skin-friendly, impact-resistant smart yarn and the smart yarn itself are disclosed. The preparation method includes: First, immersing a nanofiber membrane strip in a shear-hardening adhesive dispersion, followed by drying and unidirectional twisting to obtain an impact-resistant yarn; Second, sequentially wrapping the impact-resistant yarn and conductive metal wires with different twist directions onto an elastic yarn to obtain an elastic impact-resistant smart composite yarn; Third, coating short fibers onto the outer surface of the elastic impact-resistant smart composite yarn to obtain a highly elastic, skin-friendly, impact-resistant smart yarn. The yarn comprises an elastic yarn as the core yarn, a first wrapping layer, a second wrapping layer, and a short fiber outer layer. The impact-resistant yarn of the first wrapping layer is wrapped around the outer surface of the elastic yarn, the conductive metal wires of the second wrapping layer are wrapped around the outer surface of the first wrapping layer with opposite twist directions, and the short fiber outer layer is wrapped around the outer surface of the second wrapping layer. Therefore, this design can produce an impact-resistant yarn that simultaneously possesses high elasticity and sensing functions.

Description

Technical Field

[0001] This invention relates to a method for preparing a smart yarn and the smart yarn itself, belonging to the field of spinning technology, and particularly to a method for preparing a high-elastic, skin-friendly, impact-resistant smart yarn and the smart yarn itself. Background Technology

[0002] As working environments such as outdoor operations and extreme sports become increasingly complex, textiles that combine functionality and intelligence have become a research hotspot. Sensing yarns, as the core unit of smart textiles, are widely used in sportswear, wristbands, knee pads, and other equipment. These applications not only require yarns to have sensing properties to capture human movement postures and impact loads, but also to have impact resistance to meet protective needs during operations. Simultaneously, the yarns must also possess high elasticity and skin-friendliness to ensure flexibility of movement and long-term comfort.

[0003] However, achieving a stable integration of high elasticity, skin-friendliness, impact resistance, and sensing functions in a single yarn structure remains challenging. While high-performance fibers such as ultra-high molecular weight polyethylene and Kevlar have good impact resistance, their high modulus and low elongation mean that if used as an impact-resistant layer in a yarn structure, their high rigidity and limited stretch space will restrict the elongation and deformation of the elastic core yarn, thus limiting the overall elasticity of the yarn. Therefore, it is difficult to produce impact-resistant yarns that simultaneously possess both high elasticity and sensing functions.

[0004] Chinese patent application No. 202510994335.8, filed on July 18, 2025, discloses a multi-helix composite structure impact-resistant flexible yarn and its preparation method. The steps include: first, selecting at least two types of fiber filaments and winding them onto multiple independent yarn tubes, using spandex filaments as axes, and interlacing them in a helical winding manner to form a multi-helix yarn core; then, immersing the multi-helix yarn core material in a shear-thickening fluid energy dissipation liquid, allowing the energy dissipation liquid to fill the internal pores and helical gaps of the multi-helix yarn core material to obtain an energy-dissipating multi-helix yarn core material; finally, using a flame-retardant thermoplastic elastic material, and employing ultrasonic coating, pre-coating, hot stretching, secondary coating, and heat treatment of the energy-dissipating multi-helix yarn core material to obtain the multi-helix composite structure impact-resistant flexible yarn. Although the yarn produced by this patent possesses both flexibility and impact resistance, it still has the following drawbacks:

[0005] Although the design uses spandex filament as the axis, its outer layer is formed by a rigid skeleton tightly wrapped with high-modulus, low-elongation high-performance fibers such as aramid and ultra-high molecular weight polyethylene. When stretched, it binds the spandex core yarn, which limits the overall elasticity of the yarn. In addition, no conductive sensing layer is set, which still makes it difficult to produce an impact-resistant yarn that has both high elasticity and sensing function.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this patent application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects and problems in the existing technology that make it difficult to produce impact-resistant yarns that have both high elasticity and sensing functions at the same time, and to provide a method for preparing a high-elasticity, skin-friendly impact-resistant smart yarn and a smart yarn that can produce impact-resistant yarns that have both high elasticity and sensing functions at the same time.

[0008] To achieve the above objectives, the technical solution of the present invention is: a method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn and the smart yarn itself, wherein the preparation method includes the following steps:

[0009] Step 1: First, immerse the nanofiber membrane strip in a shear-hardening adhesive dispersion until the nanofiber membrane strip is fully immersed in the shear-hardening adhesive dispersion, then stop immersion; then heat and dry the immersed nanofiber membrane strip until it is completely dry to obtain a functional nanofiber membrane strip; then twist the functional nanofiber membrane strip to obtain an impact-resistant yarn.

[0010] Step 2: Using the stretched elastic yarn as the core yarn, the above-mentioned impact-resistant yarn and conductive metal wire are wrapped sequentially on the surface of the elastic yarn with opposite twist directions and the same twist to obtain elastic impact-resistant intelligent composite yarn.

[0011] Step 3: Use friction spinning to coat short fibers onto the surface of the above-mentioned elastic impact-resistant smart composite yarn to obtain a highly elastic, skin-friendly, impact-resistant smart yarn.

[0012] In the first step, the nanofiber membrane strip is any one or a combination of electrospun nanofiber membrane strip and centrifugally spun nanofiber membrane strip.

[0013] In the first step, the width of the nanofiber membrane strip is 5mm-40mm, and the thickness of the nanofiber membrane strip is 100μm-800μm.

[0014] In the first step, the shear-hardening adhesive dispersion is prepared by the following method:

[0015] First, the volatile organic solvent is mixed with the shear-hardening adhesive to obtain mixture A; then, mixture A is stirred in a closed environment until there are no obvious flocculent or precipitate particles, and then stirring is stopped to obtain a shear-hardening adhesive dispersion.

[0016] The solid-liquid ratio of the shear-hardening adhesive to the volatile organic solvent in the shear-hardening adhesive dispersion is 0.2g-0.7g:1ml.

[0017] In the first step, immersing the nanofiber membrane strip in the shear-hardening adhesive dispersion until the nanofiber membrane strip is fully immersed in the shear-hardening adhesive dispersion and then stopping the immersion means: immersing the nanofiber membrane strip in the shear-hardening adhesive dispersion for 20-40 minutes and then stopping the immersion.

[0018] In the first step, heating and drying the impregnated nanofiber membrane strip until it is completely dry to obtain the functional nanofiber membrane strip means: drying the impregnated nanofiber membrane strip at a temperature of 40℃-70℃ for 20min-40min to obtain the functional nanofiber membrane strip.

[0019] In the first step, twisting the functional nanofiber membrane strip means twisting the functional nanofiber membrane strip at a speed of 500rpm-3000rpm, with a twist of 2.5 twists / meter to 9 twists / meter.

[0020] In the first step, the fineness of the impact-resistant yarn is 600D-3000D.

[0021] In the second step, the fineness of the elastic yarn is 140D-980D;

[0022] In the second step, the diameter of the conductive metal wire is 10μm-60μm.

[0023] In the second step, the phrase "using the stretched elastic yarn as the core yarn, and sequentially wrapping the aforementioned impact-resistant yarn and conductive metal wire with opposite twist directions and the same twist on the surface of the elastic yarn" means:

[0024] First, the elastic yarn is stretched to a ratio of 1.5-3; then, the impact-resistant yarn is wrapped around the surface of the elastic yarn with an S-twist or Z-twist at a speed of 2000rpm-6000rpm and a twist of 800 twists / meter-1500 twists / meter; then, the conductive metal wire is wrapped around the outer surface of the impact-resistant yarn with the opposite twist direction and the same twist.

[0025] The smart yarn is prepared by the preparation method of a high-elastic, skin-friendly, impact-resistant smart yarn according to any one of claims 1-9;

[0026] The smart yarn includes an elastic yarn, a first wrapping layer, a second wrapping layer, and a short fiber outer wrapping layer;

[0027] The elastic yarn is a core yarn;

[0028] The first wrapping layer includes an impact-resistant yarn, which is wrapped around the outer surface of the elastic yarn in a first twist direction. The impact-resistant yarn is made by impregnating nanofiber membrane strips with shear-hardening adhesive, heating and drying, and twisting.

[0029] The second wrapping layer includes conductive metal wires, which are wrapped around the outer surface of the first wrapping layer with a second twist direction; the second twist direction is opposite to the first twist direction, and the conductive metal wires have the same twist as the impact-resistant yarn;

[0030] The short fiber outer layer covers the outer surface of the second wrapping layer.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. This invention discloses a method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn and the smart yarn itself. The method includes: first, immersing a nanofiber membrane strip in a shear-hardening adhesive dispersion until the nanofiber membrane strip is fully immersed in the shear-hardening adhesive dispersion, then stopping the immersion; next, heating and drying the immersed nanofiber membrane strip until it is completely dry to obtain a functional nanofiber membrane strip; then, twisting the functional nanofiber membrane strip to obtain an impact-resistant yarn; next, using a stretched elastic yarn as the core yarn, sequentially wrapping the aforementioned impact-resistant yarn and conductive metal wire with opposite twist directions and the same twist degree on the surface of the elastic yarn to obtain an elastic impact-resistant smart composite yarn; finally, using friction spinning, coating short fibers onto the surface of the aforementioned elastic impact-resistant smart composite yarn to obtain a high-elasticity, skin-friendly, impact-resistant smart yarn. The advantages of this invention also include:

[0033] First, the core yarn is made of elastic yarn that has undergone stretching treatment, which ensures the high elasticity of the yarn as a whole. The impact-resistant yarn is made of nanofiber membrane strips that are impregnated with shear-hardening adhesive and twisted. When subjected to impact load, the shear-hardening adhesive hardens rapidly and dissipates stress, achieving good impact protection performance. At the same time, the impact-resistant yarn is wrapped around the surface of the elastic yarn and can stretch with the elastic yarn, thus solving the fundamental contradiction between the high modulus and low elongation of high-performance fibers and the elasticity requirements, so that the smart yarn has both high elasticity and impact resistance.

[0034] Secondly, impact-resistant yarn and conductive metal wire are sequentially wrapped around the surface of elastic yarn with opposite twist directions and the same twist. The conductive metal wire and the short fibers coated by tribossing work together to achieve the sensing function. The conductive metal wire serves as the triboeing electrode material and the short fibers serve as the triboelectric material, enabling the yarn to have sensing capabilities. This sensing structure is achieved through physical wrapping, thereby overcoming the additional sensing difficulties caused by the chemical inertness of the high-performance fiber surface, while not affecting the original high elasticity and impact resistance of the yarn, thus achieving a stable integration of the three functions.

[0035] Thirdly, friction spinning is used to coat short fibers onto the surface of elastic, impact-resistant, intelligent composite yarn. During the friction spinning process, the short fibers are gradually coated to form a soft structure with a hairy surface, which is soft and comfortable to the touch, thus giving the yarn good skin-friendliness. The improvement in skin-friendliness does not affect the high elasticity, impact resistance, and sensing function of the yarn, making the yarn more suitable for sportswear, wristbands, knee pads, and other equipment that are worn for a long time.

[0036] Therefore, this invention can not only produce smart yarn, but also shock-resistant yarn that combines high elasticity and sensing functions.

[0037] 2. The present invention discloses a method for preparing a high-elasticity, skin-friendly, impact-resistant intelligent yarn. In the intelligent yarn, a nanofiber membrane strip is first immersed in a shear-hardening adhesive dispersion for 20-40 minutes, then the immersion is stopped. The immersed nanofiber membrane strip is then dried at a temperature of 40℃-70℃ for 20-40 minutes to obtain a functional nanofiber membrane strip. Finally, the functional nanofiber membrane strip is twisted at a speed of 500rpm-3000rpm, with a twist of 2.5 twists / meter to 9 twists / meter. The advantages of this invention also include:

[0038] Firstly, the nanofiber membrane strips are thin, flexible, and bendable, maintaining good flexibility even after being impregnated with shear-hardening adhesive. Simultaneously, the nanofiber membrane possesses a high specific surface area and high porosity. The high specific surface area provides numerous adhesion sites for the shear-hardening adhesive, allowing it to form a highly loaded adsorption layer on the fiber surface, and the colloid tightly binds to the fiber after drying. The high porosity enables the shear-hardening adhesive dispersion to quickly and unimpededly penetrate into the membrane, avoiding surface accumulation and internal underloading, thus achieving uniform impregnation from the surface inwards. This results in yarns with good impact resistance; tests show that fabrics made from this smart yarn have an energy absorption rate of 60%-78%.

[0039] Secondly, after impregnation, drying, and twisting, the flat nanofiber membrane strips are made into cylindrical impact-resistant yarn. When this impact-resistant yarn is spirally wrapped around the surface of the elastic yarn, the wrapping area is small, and a high wrapping twist can be designed, allowing the impact-resistant yarn to stretch and elongate together with the elastic yarn, thereby ensuring the overall high elasticity of the smart yarn. Tests show that the breaking elongation of this smart yarn reaches 100%-250%.

[0040] Therefore, this invention can not only produce impact-resistant yarns that have both high elasticity and sensing function, but also has high impact resistance and elasticity.

[0041] 3. The present invention discloses a method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn and the smart yarn thereof. The smart yarn comprises a short fiber outer sheath. An impact-resistant yarn of the first sheath layer is wound around the outer surface of the elastic yarn in a first twist direction. A conductive metal wire of the second sheath layer is wound around the outer surface of the first sheath layer in a second twist direction. The short fiber outer sheath layer covers the outer surface of the second sheath layer. In application, the short fiber outer sheath layer is formed through friction spinning. Friction spinning causes the short fibers to gradually coat the core yarn surface, forming a layer-by-layer fiber coating structure. This imparts softness and hairy characteristics to the outer sheath layer, resulting in a yarn surface friction coefficient as low as 0.2-0.4. A lower friction coefficient reduces resistance and itching upon skin contact, providing a soft and comfortable feel when in contact with human skin, thus giving the yarn excellent skin-friendliness. Therefore, the present invention not only possesses high impact resistance and elasticity but also improves skin-friendliness.

[0042] 4. In the preparation method of the high-elasticity, skin-friendly, impact-resistant smart yarn of the present invention, and in the smart yarn itself, the short fiber outer layer of the friction-spun yarn completely covers the internal elastic impact-resistant smart composite yarn. Neither the internal impact-resistant yarn nor the conductive metal wire is exposed on the yarn surface. During washing, the short fiber outer layer ensures the integrity of the composition and structure of the internal impact-resistant yarn and conductive metal wire, thus exhibiting good washability. During friction, the outer friction-spun short fiber layer itself possesses abrasion resistance, providing protection for the cross-wound impact-resistant yarn and conductive metal wire, thus exhibiting good friction durability. Therefore, the present invention not only improves skin-friendliness but also ensures the durability of impact resistance and sensing functions. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating the present invention.

[0044] Figure 2 This is a physical image of the nanofiber membrane strip used in this invention.

[0045] Figure 3 This is a microscope image of the impact-resistant yarn used in this invention.

[0046] Figure 4 This is a microscope image of the elastic impact-resistant smart composite yarn in this invention.

[0047] Figure 5 This is a microscope image of the high-elasticity, skin-friendly, impact-resistant smart yarn of this invention.

[0048] Figure 6 This is a microscope image of the cross-section of the high-elasticity, skin-friendly, impact-resistant smart yarn of this invention.

[0049] Figure 7 This is a schematic diagram illustrating the manufacturing process of the impact-resistant yarn in this invention.

[0050] Figure 8This is a schematic diagram illustrating the manufacturing process of the elastic impact-resistant intelligent composite yarn in this invention.

[0051] Figure 9 This is a schematic diagram illustrating the manufacturing process of the high-elasticity, skin-friendly, impact-resistant smart yarn of this invention.

[0052] Figure 10 This is a graph showing the output voltage of the fabric prepared by the smart yarn in this invention under different impact forces.

[0053] In the diagram: 1. Nanofiber membrane strip; 11. Functional nanofiber membrane strip; 12. Impact-resistant yarn; 13. Shear-hardening adhesive dispersion; 2. Elastic yarn; 3. Conductive metal wire; 4. Elastic impact-resistant intelligent composite yarn; 5. Short fiber; 6. High-elastic skin-friendly impact-resistant intelligent yarn; 7. Impregnation and twisting device; 100. Feeding roller; 101. Feeding guide rod; 103. Impregnation tank; 104. Impregnation roller; 105. Heating mechanism; 106. Twisting mechanism; 107. Output roller; 108. Winding roller; 109. Hollow spindle covering machine device; 200. Covering and drawing mechanism; 201. Covering feed roller; 202. Lower... Hollow spindle 203, lower hollow spindle yarn tube 204, lower air ring ceramic component 205, upper hollow spindle 206, upper hollow spindle yarn tube 207, upper air ring ceramic component 208, output mechanism 209, covering guide hook 210, covering winding mechanism 211, friction spinning device 300, friction spinning feed roller 301, tensioner 302, friction roller 303, friction spinning drafting mechanism 305, combing roller 306, cylinder cover plate 307, output roller nip 308, yarn guiding traverse device 309, friction spinning guide hook 310, friction spinning winding mechanism 311. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] See Figures 1-10 A method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn and the smart yarn, wherein the preparation method includes the following steps:

[0056] Step 1: First, immerse the nanofiber membrane strip 1 in the shear-hardening adhesive dispersion 13 until the nanofiber membrane strip 1 is fully immersed in the shear-hardening adhesive dispersion 13, then stop the immersion; then heat and dry the immersed nanofiber membrane strip 1 until it is completely dry to obtain the functional nanofiber membrane strip 11; then twist the functional nanofiber membrane strip 11 to obtain the impact-resistant yarn 12;

[0057] Step 2: Using the stretched elastic yarn 2 as the core yarn, the above-mentioned impact-resistant yarn 12 and conductive metal wire 3 are wrapped sequentially on the surface of the elastic yarn 2 with opposite twist directions and the same twist, to obtain the elastic impact-resistant intelligent composite yarn 4.

[0058] Step 3: Use friction spinning to coat the surface of the above-mentioned elastic impact-resistant intelligent composite yarn 4 with short fibers 5 to obtain a high-elasticity, skin-friendly impact-resistant intelligent yarn 6.

[0059] In the first step, the nanofiber membrane strip 1 is any one or a combination of electrospun nanofiber membrane strip and centrifugally spun nanofiber membrane strip.

[0060] In the first step, the width of the nanofiber membrane strip 1 is 5mm-40mm, and the thickness of the nanofiber membrane strip 1 is 100μm-800μm.

[0061] In the first step, the shear-hardening adhesive dispersion 13 is prepared by the following method:

[0062] First, the volatile organic solvent is mixed with the shear-hardening adhesive to obtain mixture A; then, mixture A is stirred in a closed environment until there are no obvious flocculent or precipitate particles in mixture A, and then stirring is stopped to obtain shear-hardening adhesive dispersion 13.

[0063] The solid-liquid ratio of the shear-hardening adhesive to the volatile organic solvent in the shear-hardening adhesive dispersion 13 is 0.2g-0.7g:1ml.

[0064] In the first step, immersing the nanofiber membrane strip 1 in the shear-hardening adhesive dispersion 13 until the nanofiber membrane strip 1 is fully immersed in the shear-hardening adhesive dispersion 13 and then stopping the immersion means: immersing the nanofiber membrane strip 1 in the shear-hardening adhesive dispersion 13 for 20 min-40 min and then stopping the immersion.

[0065] In the first step, heating and drying the impregnated nanofiber membrane strip 1 until it is completely dry to obtain the functional nanofiber membrane strip 11 means: drying the impregnated nanofiber membrane strip 1 at a temperature of 40℃-70℃ for 20min-40min to obtain the functional nanofiber membrane strip 11.

[0066] In the first step, twisting the functional nanofiber membrane strip 11 means twisting the functional nanofiber membrane strip 11 at a rotation speed of 500rpm-3000rpm, with a twist of 2.5 twists / meter to 9 twists / meter.

[0067] In the first step, the fineness of the impact-resistant yarn 12 is 600D-3000D.

[0068] In the second step, the fineness of the elastic yarn 2 is 140D-980D;

[0069] In the second step, the diameter of the conductive metal wire 3 is 10μm-60μm.

[0070] In the second step, the phrase "using the stretched elastic yarn 2 as the core yarn, and sequentially wrapping the aforementioned impact-resistant yarn 12 and conductive metal wire 3 with opposite twist directions and the same twist on the surface of the elastic yarn 2" means:

[0071] First, the elastic yarn 2 is stretched to a ratio of 1.5-3; then, the impact-resistant yarn 12 is wrapped around the surface of the elastic yarn 2 with an S-twist or Z-twist at a speed of 2000rpm-6000rpm and a twist of 800 twists / meter-1500 twists / meter; then, the conductive metal wire 3 is wrapped around the outer surface of the impact-resistant yarn 12 with the opposite twist direction and the same twist.

[0072] The smart yarn is prepared by the preparation method of a high-elastic, skin-friendly, impact-resistant smart yarn according to any one of claims 1-9;

[0073] The smart yarn includes an elastic yarn 2, a first wrapping layer, a second wrapping layer, and a short fiber outer wrapping layer;

[0074] The elastic yarn 2 is the core yarn;

[0075] The first wrapping layer includes an impact-resistant yarn 12, which is wrapped around the outer surface of the elastic yarn 2 with a first twist direction. The impact-resistant yarn 12 is made by impregnating nanofiber membrane strips 1 with shear-hardening adhesive, heating and drying, and twisting.

[0076] The second wrapping layer includes a conductive metal wire 3, which is wrapped around the outer surface of the first wrapping layer with a second twist direction; the second twist direction is opposite to the first twist direction, and the conductive metal wire 3 has the same twist as the impact-resistant yarn 12.

[0077] The short fiber outer layer covers the outer surface of the second wrapping layer.

[0078] The following are supplementary descriptions of the present invention:

[0079] In the preferred embodiment of the present invention, in the first step, the nanofiber membrane strip 1 is cut from a nanofiber membrane, and the nanofiber membrane is any one or any combination of PU membrane, PVDF membrane, PAN membrane, PTFE membrane, and PI membrane.

[0080] In the preferred embodiment of the present invention, in the first step, the nanofiber membrane strip 1 is cut from an electrospun nanofiber membrane; specifically, the silicone paper and the nanofiber membrane on the electrospun collecting roller are cut together, and after cutting, the nanofiber membrane is peeled off from the silicone paper to obtain a nanofiber membrane strip 1 with a width of 5mm-40mm; the method of cutting the silicone paper and the nanofiber membrane together can ensure uniform cutting and avoid uneven cutting caused by the softness and easy curling of the nanofiber membrane. At the same time, the silicone paper plays a supporting and protective role in the cutting process, preventing the nanofiber membrane from being stretched, deformed or damaged during cutting.

[0081] The shear-hardening adhesive of this invention is a polyborosiloxane material; it is formed by the dehydration condensation of hydroxyl silicone oil with boron-oxygen main chain and boron source material (such as boric acid) at high temperature. The dynamic BO bonds contained in its molecular structure enable it to harden and dissipate energy rapidly when subjected to high-speed impact, and restore its softness after the external force is removed, thus possessing both protective properties and flexibility.

[0082] In the second step of this invention, the elastic yarn 2 is any one or a combination of spandex elastic yarn and silicone tube; the function of the elastic yarn 2 is to provide high elasticity for the smart yarn, so that the breaking elongation of the smart yarn reaches 100%-250%; therefore, any elastic filament that can meet the high elasticity requirement can be used as the core yarn, which provides greater flexibility for the diversified design and application of yarn.

[0083] In the second step of this invention, the conductive metal wire 3 is any one or any combination of copper wire, stainless steel wire, and nickel wire.

[0084] In the third step of this invention, the short fiber 5 is a sliver, that is, a fiber sliver with a certain degree of evenness produced by processes such as carding and drawing.

[0085] In the first step of this invention, the purpose of twisting is to form the strip-shaped nanofiber membrane 1 into a cylindrical yarn, which is the basis for achieving high elasticity and impact resistance. This is because: if the strip-shaped nanofiber membrane is used to directly wrap the elastic yarn 2, the wrapping area of ​​the strip-shaped membrane is large, and the elongation of the nanofiber membrane 1 during stretching cannot match the elongation of the elastic yarn 2, thereby restricting the deformation of the elastic yarn 2 and resulting in poor overall elasticity of the composite yarn; however, after forming a cylindrical yarn, the wrapping area is small under the same wrapping twist, and a higher wrapping twist can be designed so that the wrapped yarn can be stretched and elongated together with the elastic yarn 2, thereby giving the composite yarn high elasticity.

[0086] In the first step of this invention, the content of shear hardening adhesive on the impregnated nanofiber membrane strip 1 is 30wt.%-60wt.%. This content is crucial for ensuring the performance of the impact-resistant yarn. If the shear hardening adhesive content is too low (<30wt.%), the adhesive loading is insufficient, making it difficult to form a continuous and complete energy-dissipating layer in the fiber network, resulting in a significant decrease in impact resistance. If the shear hardening adhesive content is too high (>60wt.%), the shear hardening adhesive inside the fiber membrane is easily squeezed to the fiber surface during twisting. The shear hardening adhesive remaining on the surface lacks the constraint of the fiber network and will drip from the fiber surface due to its cold flow characteristics, causing adhesive loss and uneven yarn evenness, which in turn reduces the impact resistance of the yarn. Therefore, controlling the shear hardening adhesive content within the range of 30wt.%-60wt.% ensures that the impact-resistant yarn has sufficient adhesive loading to achieve excellent energy dissipation while maintaining structural uniformity and stability.

[0087] The hollow spindle covering machine device 200 described in this invention is the HKV141D hollow spindle covering device from Zhejiang Jinggong Technology Co., Ltd.

[0088] In the first step of this invention, the impregnation and twisting are both carried out at room temperature.

[0089] In the first step of this invention, the phrase "until the nanofiber membrane strip 1 is fully impregnated with the shear-hardening adhesive dispersion 13" means that when the nanofiber membrane strip 1 is lifted and the shear-hardening adhesive dispersion 13 is observed to drip continuously and uniformly from the nanofiber membrane strip 1, it indicates that it has been fully impregnated.

[0090] The second and third steps of this invention are both performed at room temperature.

[0091] The room temperature described in this invention is 20℃-30℃; preferably 25℃.

[0092] Example 1:

[0093] See Figures 1-10 A method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn and the smart yarn, wherein the preparation method includes the following steps:

[0094] Step 1: First, immerse the nanofiber membrane strip 1 in the shear-hardening adhesive dispersion 13 until the nanofiber membrane strip 1 is fully immersed in the shear-hardening adhesive dispersion 13, then stop the immersion; then heat and dry the immersed nanofiber membrane strip 1 until it is completely dry to obtain the functional nanofiber membrane strip 11; then twist the functional nanofiber membrane strip 11 to obtain the impact-resistant yarn 12;

[0095] Step 2: Using the stretched elastic yarn 2 as the core yarn, the above-mentioned impact-resistant yarn 12 and conductive metal wire 3 are wrapped sequentially on the surface of the elastic yarn 2 with opposite twist directions and the same twist, to obtain the elastic impact-resistant intelligent composite yarn 4.

[0096] Step 3: Use friction spinning to coat the surface of the above-mentioned elastic impact-resistant intelligent composite yarn 4 with short fibers 5 to obtain a high-elasticity, skin-friendly impact-resistant intelligent yarn 6.

[0097] Example 2:

[0098] The basic content is the same as in Example 1, except that: in the first step, the nanofiber membrane strip 1 is any one or a combination of electrospun nanofiber membrane strip and centrifugally spun nanofiber membrane strip; in the first step, the width of the nanofiber membrane strip 1 is 5mm-40mm, and the thickness of the nanofiber membrane strip 1 is 100μm-800μm.

[0099] When applying, such as Figure 2As shown, the nanofiber membrane strip 1 is thin, flexible, and bendable, and retains good flexibility after being impregnated with the shear-hardening adhesive dispersion 13. Electrospun or centrifugally spun nanofiber membrane strips are chosen as the substrate because they have high specific surface area and high porosity: the high specific surface area allows the shear-hardening adhesive dispersion 13 to be fully adsorbed on the fiber surface, achieving high loading capacity and strong bonding; the high porosity allows the dispersion to penetrate into the membrane quickly and without obstruction, avoiding surface accumulation and internal underloading, thereby achieving uniform impregnation from the surface to the inside.

[0100] The width of the nanofiber membrane strip 1 is 5mm-40mm because: if the width of the nanofiber membrane strip 1 is too narrow (<5mm), the mechanical properties of the nanofiber membrane strip 1 are poor, and it is easy to break during subsequent twisting and wrapping processes. In addition, the content of shear hardening adhesive attached during impregnation is low, affecting the impact resistance. If the width of the nanofiber membrane strip 1 is too wide (>40mm), due to the softness of the nanofiber, it is easy to curl during impregnation, resulting in uneven impregnation. Furthermore, the diameter and stiffness of the yarn obtained after twisting are large, which can easily lead to inconsistent wrapping forces between the upper and lower spindles during wrapping, causing yarn twisting and uneven wrapping. Therefore, this width range ensures both the mechanical strength and impregnation uniformity of the nanofiber membrane strip 1, and is also conducive to the stable progress of subsequent twisting and wrapping processes.

[0101] The thickness of the nanofiber membrane strip 1 is 100μm-800μm because: if the thickness of the nanofiber membrane strip 1 is too small (<100μm), the impregnated shear hardener content will be low, affecting the impact resistance; if the thickness is too large (>800μm), a larger twist will be required in the subsequent unidirectional twisting step, which will cause the shear hardener attached inside the nanofiber membrane to be squeezed to the surface, resulting in unevenness of the impact-resistant yarn 12, thus affecting the impact resistance of the yarn; therefore, this thickness range ensures an appropriate load of shear hardener while avoiding unevenness caused by excessive compression of the colloid during twisting.

[0102] Example 3:

[0103] The basic content is the same as in Example 1, except that: in the first step, the shear hardening adhesive dispersion 13 is prepared by the following method: first, a volatile organic solvent is mixed with the shear hardening adhesive to obtain mixture A; then, in a closed environment, mixture A is stirred until there are no obvious flocculent or precipitate substances in mixture A, and then stirring is stopped to obtain shear hardening adhesive dispersion 13; the solid-liquid ratio of shear hardening adhesive to volatile organic solvent in the shear hardening adhesive dispersion 13 is 0.2g-0.7g:1ml.

[0104] In application, the volatile organic solvent is any one or a combination of anhydrous ethanol and acetone. The role of the volatile organic solvent is to dissolve and disperse the shear-hardening adhesive to form a uniform and stable shear-hardening adhesive dispersion 13, so that the colloid can fully penetrate and adhere to the fiber network when the nanofiber membrane strip 1 is impregnated. The selected solvent must have good solubility for the shear-hardening adhesive, and a fast evaporation rate, so that it can be quickly removed after impregnation without affecting the colloidal properties. Anhydrous ethanol and acetone are both low-boiling-point organic solvents (boiling point below 120°C under standard atmospheric pressure), with a fast evaporation rate at room temperature, which can be quickly dried after impregnation to avoid solvent residue. Both have good solubility for the shear-hardening adhesive and can form a stable dispersion system. Among them, anhydrous ethanol has low toxicity and good safety, while acetone has stronger solubility.

[0105] The solid-liquid ratio of the shear-hardening adhesive dispersion 13 determines the loading amount and distribution uniformity of the shear-hardening adhesive on the nanofiber membrane strip 1 after impregnation. If the solid-liquid ratio is too low (<0.2g:1ml), the shear-hardening adhesive content is too low, resulting in a low content of shear-hardening adhesive adhering to the nanofiber membrane strip 1 after impregnation, which affects the impact resistance performance. If the solid-liquid ratio is too high (>0.7g:1ml), the dispersion concentration is too high, and the shear-hardening adhesive is prone to agglomeration or local enrichment during impregnation. Furthermore, it is easily squeezed to the fiber surface during subsequent twisting, causing unevenness in the slivers of the impact-resistant yarn 12 and affecting the stability of the impact resistance performance. Therefore, selecting this solid-liquid ratio range can achieve uniform distribution while ensuring sufficient adhesive loading.

[0106] The specific preparation process is as follows: Shear-hardening adhesive and volatile organic solvent are added to a container at a solid-liquid ratio of 0.2g-0.7g:1ml to obtain mixture A. Mixture A is then stirred using a magnetic stirrer. During stirring, the container opening is sealed with a sealing film to prevent solvent evaporation. The stirring speed is 200rpm-500rpm, and stirring is carried out for 1-3 hours to obtain a shear-hardening adhesive dispersion. If the stirring speed is too low (<200rpm), the efficiency is low and the required time is long; if the speed is too high (>500rpm), solvent evaporation is likely to occur; if the stirring time is too short (<1 hour), the shear-hardening adhesive will not dissolve sufficiently; if the time is too long (>3 hours), solvent evaporation will also occur.

[0107] Example 4:

[0108] The basic content is the same as in Example 1, except that: in the first step, immersing the nanofiber membrane strip 1 in the shear-hardening adhesive dispersion 13 until the nanofiber membrane strip 1 is fully immersed in the shear-hardening adhesive dispersion 13 and then stopping the immersion means: immersing the nanofiber membrane strip 1 in the shear-hardening adhesive dispersion 13 for 20-40 minutes and then stopping the immersion; in the first step, heating and drying the immersed nanofiber membrane strip 1 until the immersed nanofiber membrane strip 1 is completely dry to obtain the functional nanofiber membrane strip 11 means: drying the immersed nanofiber membrane strip 1 at a temperature of 40℃-70℃ for 20-40 minutes to obtain the functional nanofiber membrane strip 11; in the first step, twisting the functional nanofiber membrane strip 11 means: twisting the functional nanofiber membrane strip 11 at a speed of 500rpm-3000rpm, with a twist of 2.5 twists / meter-9 twists / meter.

[0109] When applying, such as Figure 7 As shown, the first step is achieved using an impregnation and twisting device 100. The impregnation and twisting device 100 includes a feed roller 101, a feed guide rod 103, an impregnation tank 104, an impregnation roller 105, a heating mechanism 106, a twisting mechanism 107, an output roller 108, and a winding roller 109. The shear-hardening adhesive dispersion 13 is placed in the impregnation tank 104. Specifically, the nanofiber membrane strip 1 is first placed on the feed roller 101 and then introduced into the impregnation tank 104 via the feed guide rod 103, where it is impregnated in the shear-hardening adhesive dispersion 13 for 20-40 minutes. After impregnation, The nanofiber membrane strip 1 is then output and held by the impregnation roller 105, and heated and dried by the heating mechanism 106 at a temperature of 40℃-70℃ for 20min-40min to remove residual solvent, resulting in a functional nanofiber membrane strip 11. Then, the functional nanofiber membrane strip 11 is twisted by the twisting mechanism 107 at a speed of 500rpm-3000rpm, with a twist of 2.5 twists / meter-9 twists / meter, resulting in an impact-resistant yarn 12. Finally, the impact-resistant yarn 12 is conveyed to the winding roller 109 for collection via the output roller 108.

[0110] The impregnation time is 20-40 minutes because: if the impregnation time is too short (<20 minutes), the shear-hardening adhesive dispersion 13 cannot fully penetrate into the nanofiber membrane strip 1, resulting in insufficient impregnation, insufficient colloidal loading, and affecting the impact resistance performance; if the impregnation time is too long (>40 minutes), as the volatile organic solvent (such as ethanol) evaporates, the shear-hardening adhesive dispersion 13 gradually thickens, easily forming accumulation on the surface of the nanofiber membrane strip 1 while the interior is unloaded, causing uneven impregnation, which also affects the stability of the impact resistance performance.

[0111] The purpose of heat drying is to remove residual solvent. The drying temperature is 40℃-70℃, and the drying time is 20min-40min because: if the drying temperature is too low (<40℃) or the time is too short (<20min), the solvent cannot be completely removed, and the residual solvent will affect the curing effect of the shear-hardening adhesive. In addition, during the subsequent twisting process, the undried shear-hardening adhesive is easily squeezed out of the fiber network under torque, resulting in a decrease in impact resistance. If the drying temperature is too high (>70℃) or the time is too long (>40min), it may damage the structure of the nanofiber membrane strip 1 and increase energy consumption. In addition, keeping the heat drying time consistent with the impregnation time allows the impregnation and drying processes to be carried out continuously, improving production efficiency.

[0112] The purpose of twisting is to form the strip-shaped nanofiber membrane 1 into a cylindrical yarn. The twisting speed is 500rpm-3000rpm, and the twist is 2.5 twists / meter-9 twists / meter because: if the twisting speed is too low (<500rpm), the twisting efficiency is low, the yarn density is insufficient, the friction and cohesion between fibers are small, and the mechanical properties of the impact-resistant yarn 12 are poor; if the twisting speed is too high (>3000rpm), it may cause excessive stretching damage to the fibers, affecting the mechanical properties of the yarn; the twist is... A twist rate of 2.5-9 twists / meter ensures that the impact-resistant yarn 12 has a suitable tightness and cylindrical structure. If the twist is too low (<2.5 twists / meter), the yarn structure will be loose and it will be difficult to maintain a cylindrical shape. If the twist is too high (>9 twists / meter), the shear hardening adhesive attached to the inside of the nanofiber membrane will be squeezed to the surface, resulting in uneven yarn and thus affecting the impact resistance. Tests show that the breaking strength of the impact-resistant yarn 12 obtained through this twisting process is 5-60 MPa and the breaking elongation is 20-55%.

[0113] Example 5:

[0114] The basic content is the same as in Example 1, except that in the first step, the fineness of the impact-resistant yarn 12 is 600D-3000D.

[0115] In application, the fineness of the impact-resistant yarn 12 is closely related to the thickness and width of the nanofiber membrane strip 1 and the content of shear-hardening adhesive attached after impregnation. The fineness of the impact-resistant yarn 12 is selected as 600D-3000D because: if the fineness is too low (<600D), the nanofiber membrane strip 1 will be too thin or too narrow, or the content of shear-hardening adhesive after impregnation will be too low, resulting in insufficient mechanical properties and impact resistance of the impact-resistant yarn 12; if the fineness is too high (>3000D), the nanofiber membrane strip 1 will be too thick or too wide, or the content of shear-hardening adhesive after impregnation will be too high, which will easily squeeze the adhesive to the fiber surface during subsequent twisting, causing uneven yarn evenness. In addition, the yarn diameter and stiffness are large, which can easily lead to inconsistent wrapping force during wrapping, causing yarn twisting and uneven wrapping.

[0116] Example 6:

[0117] The basic content is the same as in Example 1, except that: in the second step, the fineness of the elastic yarn 2 is 140D-980D; and in the second step, the diameter of the conductive metal wire 3 is 10μm-60μm.

[0118] When applying this material, the fineness of the elastic yarn 2 is selected as 140D-980D because: if the fineness of the elastic yarn 2 is too low (<140D), the fineness of the impact-resistant yarn 12 will be significantly greater than that of the elastic yarn 2. During the wrapping process, the elastic yarn 2 will be stretched and elongated. After it leaves the machine, the elastic yarn 2 will spring back, causing the wrapped impact-resistant yarn 12 to untwist, affecting the structural stability. If the fineness of the elastic yarn 2 is too high (>980D), the overall fineness of the yarn will be too large, affecting subsequent weaving processing and wearing comfort. Therefore, this fineness range ensures the stability of the wrapping structure while also taking into account the processability and wearability of the yarn.

[0119] The diameter of the conductive metal wire 3 is selected from 10μm to 60μm because: if the diameter is too small (<10μm), the mechanical properties of the conductive metal wire 3 are weak, and it is easy to break during the winding process, affecting production efficiency and the continuity of yarn conductivity; if the diameter is too large (>60μm), the flexibility of the conductive metal wire 3 deteriorates, which is not conducive to the stable progress of the winding process, and the overall stiffness of the yarn increases, affecting wearing comfort; therefore, the diameter range of 10μm-60μm ensures that the conductive metal wire 3 has good mechanical and conductive properties, and also ensures its flexibility and processability during the winding process.

[0120] Example 7:

[0121] The basic content is the same as in Example 1, except that in the second step, the phrase "using the stretched elastic yarn 2 as the core yarn and wrapping the impact-resistant yarn 12 and the conductive metal wire 3 with opposite twist directions and the same twist in sequence around the surface of the elastic yarn 2" means: first, the elastic yarn 2 is stretched to a ratio of 1.5-3; then, the impact-resistant yarn 12 is wrapped around the surface of the elastic yarn 2 with an S-twist or Z-twist at a rotation speed of 2000rpm-6000rpm and a twist of 800 twists / meter-1500 twists / meter; and finally, the conductive metal wire 3 is wrapped around the outer surface of the impact-resistant yarn 12 with opposite twist directions and the same twist.

[0122] When applying, such as Figure 8As shown, the second step is achieved using a hollow spindle covering yarn machine device 200; the hollow spindle covering yarn machine device 200 includes a covering drafting mechanism 201, a covering feed roller 202, a lower hollow spindle 203, a lower hollow spindle yarn tube 204, a lower air ring ceramic component 205, an upper hollow spindle 206, an upper hollow spindle yarn tube 207, an upper air ring ceramic component 208, an output mechanism 209, a covering yarn guide hook 210, and a covering winding mechanism 211;

[0123] The covering process of the hollow spindle covering yarn machine device 200 is as follows: First, the elastic yarn 2 is placed on the covering drafting mechanism 201 and fed in by the covering feed roller 202. It then passes through the lower hollow spindle 203, the lower air ring ceramic part 205, the upper hollow spindle 206, the upper air ring ceramic part 208, the output mechanism 209, and the covering yarn guide hook 210 in sequence, and is finally fixed on the yarn bobbin of the covering winding mechanism 211. Then, the impact-resistant yarn 12 prepared in the first step is placed in the lower hollow spindle yarn tube 204 (this placement position allows the impact-resistant yarn 12 to first wrap around the outer surface of the elastic yarn 2), and the yarn end of the impact-resistant yarn 12 is fixed on the elastic yarn 2 below the lower air ring ceramic part 205. At the same time, the conductive metal wire 3 is placed in the upper hollow spindle yarn tube 207. (This placement position allows the conductive metal wire 3 to be wrapped around the outer surface of the impact-resistant yarn 12), and the yarn end of the conductive metal wire 3 is fixed on the elastic yarn 2 in the lower section of the upper air ring ceramic component 208; during wrapping, the elastic yarn 2 is first stretched by the wrapping stretching mechanism 201, and the impact-resistant yarn 12 is first wrapped around the surface of the stretched elastic yarn 2 by the lower air ring ceramic component 205 to form the first wrapping layer; subsequently, the conductive metal wire 3 is wrapped around the outer surface of the first wrapping layer by the upper air ring ceramic component 208 with the same rotation speed and twist, but opposite twist direction to form the second wrapping layer, thereby obtaining the elastic impact-resistant intelligent composite yarn 4; after passing through the output mechanism 209 and the wrapping guide hook 210, the elastic impact-resistant intelligent composite yarn 4 is wound and collected by the wrapping winding mechanism 211;

[0124] The draft ratio determines the pre-stretch degree of elastic yarn 2 during the wrapping process. The draft ratio is selected as 1.5-3 because: if the draft ratio is too low (<1.5), the pre-stretch of elastic yarn 2 is insufficient, the yarn structure is not tight after wrapping, and it is easy to untwist after leaving the machine, resulting in a loose wrapping layer; if the draft ratio is too high (>3), elastic yarn 2 is overstretched, the elasticity is weakened, the extensibility of the composite yarn is insufficient, and it is difficult to meet the high elasticity requirements.

[0125] The rotation speed of 2000rpm-6000rpm refers to the rotation speed between the lower hollow spindle 203 and the upper hollow spindle 206. The reason for choosing 2000-6000rpm is that if the rotation speed is too low (<2000rpm), the spinning efficiency will be low and the wrapping tension will be insufficient, making it difficult for the impact-resistant yarn 12 and the conductive metal wire 3 to be tightly wrapped around the surface of the elastic yarn 2. If the rotation speed is too high (>6000rpm), the wrapping tension will be too large, which may cause the impact-resistant yarn 12 and the conductive metal wire 3 to be stretched or even broken during the wrapping process, affecting the yarn quality.

[0126] The twist is selected as 800 twists / meter to 1500 twists / meter because: if the twist is too low (<800 twists / meter), the wrapping will be sparse, and the impact-resistant yarn 12, conductive metal wire 3 and elastic yarn 2 will not be tightly bonded, resulting in limited elasticity of the composite yarn; if the twist is too high (>1500 twists / meter), there will be over-twisting, the yarn will feel stiff, and it may cause uneven wrapping and deterioration of yarn evenness, which will affect the stability of impact resistance.

[0127] The rotation speed and twist of the lower hollow spindle 203 and the upper hollow spindle 206 are set to be the same because: on the one hand, consistent twist during the wrapping process can prevent the yarn from twisting, which would lead to uneven wrapping; on the other hand, consistent twist can ensure the simultaneous breakage of the composite yarn. If the twist is inconsistent, the wound impact-resistant yarn 12 and conductive metal wire 3 will break in a sequential order. Inconsistent breakage of the wrapped yarn will cause the yarn shape to suddenly loosen and the wrapping structure to fall apart.

[0128] The impact-resistant yarn 12 and the conductive metal wire 3 are twisted in opposite directions because the impact-resistant yarn 12 has a larger fineness and a greater modulus difference from the elastic core yarn. After wrapping, the conductive metal wire 3 needs to be wrapped and fixed with a different twist direction to prevent the impact-resistant yarn 12 from untwisting and to form a stable cross-wrap structure. In addition, the wrapping order is to wrap the impact-resistant yarn 12 first and then the conductive metal wire 3. This is achieved by placing the impact-resistant yarn 12 in the lower hollow spindle 203 and the conductive metal wire 3 in the upper hollow spindle 206. The reason for wrapping the impact-resistant yarn 12 first and then the conductive metal wire 3 is that the impact-resistant yarn 12, as the main impact-resistant functional layer, is wrapped first to ensure that it fits tightly with the elastic yarn 2. The conductive metal wire 3 is wrapped later, which serves as a sensing electrode material to realize the sensing function. On the other hand, it takes advantage of its small diameter and good flexibility to fix the impact-resistant yarn with a opposite twist direction to prevent it from untwisting and to provide protection.

[0129] Example 8:

[0130] The basic content is the same as in Example 1, except that in the third step, the step of coating the short fibers 5 onto the surface of the elastic impact-resistant intelligent composite yarn 4 using friction spinning means that the short fibers 5 are coated onto the surface of the elastic impact-resistant intelligent composite yarn 4 using a friction spinning device 300. The friction spinning device 300 includes a friction spinning feed roller 301, a tensioner 302, a friction roller 303, a friction spinning drafting mechanism 305, a combing roller 306, a cylinder cover plate 307, an output roller nip 308, a yarn guiding traverse device 309, a friction spinning yarn guiding hook 310, and a friction spinning winding mechanism 311. The rotational speed of the friction roller 303 is 2500 rpm-4000 rpm; the rotational speed of the combing roller 306 is 3000 rpm-5000 rpm; the feeding speed is 1 m / min-5 m / min; the output speed is 15 m / min-30 m / min; and the winding speed is 16 m / min-31 m / min.

[0131] When applying, such as Figure 9 As shown, the elastic impact-resistant intelligent composite yarn 4 obtained in the second step is used as the core yarn and fed in by the friction spinning feed roller 301. After passing through the tensioner 302, it enters the wedge-shaped groove area formed by a pair of friction rollers 303 rotating in the same direction. At the same time, the short fibers 5 are stretched by the friction spinning drafting mechanism 305 and combed by the combing roller 306 to form single fibers. They fall into the wedge-shaped groove area. Under the frictional force of the friction rollers 303 rotating in the same direction, the single fibers gradually coat the surface of the elastic impact-resistant intelligent composite yarn 4 to form a short fiber outer layer, thereby obtaining the high-elasticity skin-friendly impact-resistant intelligent yarn 6. The high-elasticity skin-friendly impact-resistant intelligent yarn 6 passes through the output roller nip 308, the yarn guiding traverse device 309, and the friction spinning yarn guiding hook 310, and is then wound and collected by the friction spinning winding mechanism 311.

[0132] The speed of friction roller 303 is selected as 2500rpm-4000rpm because: if the speed of friction roller 303 is too low (<2500rpm), the structure of the short fiber layer will be loose and it will be difficult to form a dense and uniform outer layer; if the speed is too high (>4000rpm), it will damage the elastic impact-resistant intelligent composite yarn 4, which is the core yarn, and affect the mechanical properties of the yarn.

[0133] The speed of the combing roller 306 is selected as 3000rpm-5000rpm because: if the speed of the combing roller 306 is too low (<3000rpm), the feeding short fiber sliver will not be fully opened and combed, the degree of single fiberization will be low, resulting in uneven coating layer and uneven thickness of composite yarn; if the speed is too high (>5000rpm), it will damage the feeding short fiber 5 and affect the quality of the outer coating layer.

[0134] The feeding speed is selected as 1m / min-5m / min, the output speed as 15m / min-30m / min, and the winding speed as 16m / min-31m / min because: the feeding speed and the output speed together determine the thickness of the friction-spun short fiber coating layer; if the feeding speed is too small (<1m / min) and the output speed is too large (>30m / min), the short fiber 5 cannot completely cover the elastic impact-resistant intelligent composite yarn 4 as the core yarn, resulting in the internal functional yarn being exposed; if the feeding speed is too large (>5m / min), it will block the combing roller and affect the spinning stability; the winding speed is usually 1m / min larger than the output speed to ensure that the yarn maintains appropriate tension during the winding process and avoids slack or excessive stretching.

[0135] Example 9:

[0136] The basic content is the same as in Embodiment 1, except that: the smart yarn is prepared by the preparation method of a high-elasticity, skin-friendly, impact-resistant smart yarn according to any one of claims 1-9; the smart yarn includes an elastic yarn 2, a first wrapping layer, a second wrapping layer, and a short fiber outer layer; the elastic yarn 2 is a core yarn; the first wrapping layer includes an impact-resistant yarn 12, which is wrapped around the outer surface of the elastic yarn 2 with a first twist direction, and the impact-resistant yarn 12 is made by impregnating a nanofiber membrane strip 1 with shear-hardening adhesive, heating and drying, and twisting; the second wrapping layer includes a conductive metal wire 3, which is wrapped around the outer surface of the first wrapping layer with a second twist direction; the second twist direction is opposite to the first twist direction, and the conductive metal wire 3 has the same twist as the impact-resistant yarn 12; the short fiber outer layer covers the outer surface of the second wrapping layer.

[0137] In application, the high-elastic, skin-friendly, impact-resistant smart yarn 6 is made into a fabric. When subjected to a sudden high-speed impact, the impact-resistant yarn 12 in the first wrapping layer responds first: the shear-hardening adhesive in the impact-resistant yarn 12 hardens rapidly under the impact load to dissipate stress. At the same time, the impact-resistant yarn 12 is stretched in a spiral manner and rubs against each other, forming an energy dissipation mechanism. The conductive metal wire 3 in the second wrapping layer maintains structural integrity during the impact process, providing stable support for the impact-resistant yarn 12, and works with the short fiber outer wrapping layer to achieve the sensing function. The two wrapping layers adopt opposite twist directions, so that the yarn is subjected to uniform stress, effectively preventing the wrapping structure from untwisting and ensuring the stability of the impact resistance performance. The outermost short fiber sheath consists of a layered short fiber 5 structure, which is soft and has a hairy texture, resulting in a yarn surface friction coefficient as low as 0.2-0.4. This makes it soft and comfortable to the touch when in contact with human skin. At the same time, it completely covers the internal functional layers, ensuring the structural integrity of the yarn during washing and friction. Tests have shown that the breaking elongation of this high-elasticity, skin-friendly, impact-resistant smart yarn 6 reaches 100%-250%, and the fabric made from this high-elasticity, skin-friendly, impact-resistant smart yarn 6 has an energy absorption rate of 60%-78%. It has high elasticity, impact resistance, sensing function, and skin-friendliness, and can be widely used in sportswear, wristbands, knee pads, and other long-term wear equipment.

[0138] See Figure 10 The figure shows the output voltage results of the fabric made of the smart yarn of the present invention under different impact forces. It can be seen that as the impact force increases, the output voltage signal of the fabric also increases. This indicates that the fabric has sensing performance and can effectively monitor the magnitude of the impact force through the change of output voltage. It can be used to sense human movement posture or external impact load in real time.

[0139] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn, characterized in that: The preparation method includes the following steps: Step 1: First, immerse the nanofiber membrane strip (1) in the shear-hardening adhesive dispersion (13) until the nanofiber membrane strip (1) is fully immersed in the shear-hardening adhesive dispersion (13), then stop immersion; then heat and dry the immersed nanofiber membrane strip (1) until it is completely dry to obtain the functional nanofiber membrane strip (11); then twist the functional nanofiber membrane strip (11) to obtain the impact-resistant yarn (12). Step 2: Using the stretched elastic yarn (2) as the core yarn, the above-mentioned impact-resistant yarn (12) and conductive metal wire (3) are wrapped sequentially on the surface of the elastic yarn (2) with opposite twist directions and the same twist to obtain elastic impact-resistant intelligent composite yarn (4). Step 3: Use friction spinning to coat short fibers (5) onto the surface of the above elastic impact-resistant intelligent composite yarn (4) to obtain a high-elasticity skin-friendly impact-resistant intelligent yarn (6).

2. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the first step, the nanofiber membrane strip (1) is any one or a combination of electrospun nanofiber membrane strip and centrifugally spun nanofiber membrane strip.

3. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the first step, the width of the nanofiber membrane strip (1) is 5mm-40mm, and the thickness of the nanofiber membrane strip (1) is 100μm-800μm.

4. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the first step, the shear-hardening adhesive dispersion (13) is prepared by the following method: First, the volatile organic solvent is mixed with the shear hardening adhesive to obtain mixture A; then, mixture A is stirred in a closed environment until there are no obvious flocculent or precipitate in mixture A, and then the stirring is stopped to obtain the shear hardening adhesive dispersion (13).

5. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 4, characterized in that: The solid-liquid ratio of shear-hardening adhesive to volatile organic solvent in the shear-hardening adhesive dispersion (13) is 0.2g-0.7g:1ml.

6. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the first step, the step of immersing the nanofiber membrane strip (1) in the shear hardening adhesive dispersion (13) until the nanofiber membrane strip (1) is fully immersed in the shear hardening adhesive dispersion (13) and then stopping the immersion means: immersing the nanofiber membrane strip (1) in the shear hardening adhesive dispersion (13) for 20 min-40 min and then stopping the immersion. In the first step, heating and drying the impregnated nanofiber membrane strip (1) until the impregnated nanofiber membrane strip (1) is completely dry to obtain the functional nanofiber membrane strip (11) means: drying the impregnated nanofiber membrane strip (1) at a temperature of 40℃-70℃ for 20min-40min to obtain the functional nanofiber membrane strip (11). In the first step, twisting the functional nanofiber membrane strip (11) means twisting the functional nanofiber membrane strip (11) at a speed of 500rpm-3000rpm, with a twist of 2.5 twists / meter to 9 twists / meter.

7. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the first step, the fineness of the impact-resistant yarn (12) is 600D-3000D.

8. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the second step, the fineness of the elastic yarn (2) is 140D-980D; In the second step, the diameter of the conductive metal wire (3) is 10μm-60μm.

9. The method for preparing a high-elasticity, skin-friendly, impact-resistant smart yarn according to claim 1, characterized in that: In the second step, the phrase "using the stretched elastic yarn (2) as the core yarn, and wrapping the aforementioned impact-resistant yarn (12) and conductive metal wire (3) sequentially with opposite twist directions and the same twist on the surface of the elastic yarn (2)" means: First, the elastic yarn (2) is stretched to a ratio of 1.5-3; then, the impact-resistant yarn (12) is wrapped around the surface of the elastic yarn (2) with an S-twist or Z-twist at a speed of 2000rpm-6000rpm and a twist of 800 twists / meter-1500 twists / meter; then, the conductive metal wire (3) is wrapped around the outer surface of the impact-resistant yarn (12) with the opposite twist direction and the same twist.

10. A highly elastic, skin-friendly, impact-resistant intelligent yarn, characterized in that: The smart yarn is prepared by the preparation method of a high-elastic, skin-friendly, impact-resistant smart yarn according to any one of claims 1-9; The smart yarn includes an elastic yarn (2), a first wrapping layer, a second wrapping layer, and a short fiber outer wrapping layer; The elastic yarn (2) is the core yarn; The first wrapping layer includes an impact-resistant yarn (12), which is wrapped around the outer surface of the elastic yarn (2) with a first twist direction. The impact-resistant yarn (12) is made by impregnating nanofiber membrane strips (1) with shear-hardening adhesive, heating and drying, and twisting. The second wrapping layer includes a conductive metal wire (3), which is wrapped around the outer surface of the first wrapping layer with a second twist direction; the second twist direction is opposite to the first twist direction, and the conductive metal wire (3) has the same twist as the impact-resistant yarn (12); The short fiber outer layer covers the outer surface of the second wrapping layer.

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