Multilayer fast heat-conducting high-temperature-resistant elastic yarn and preparation method thereof

Abstract

The application provides a multi-layer fast heat-conducting high-temperature-resistant elastic yarn and a preparation method thereof. The yarn comprises, from inside to outside, an elastic core yarn, a functional layer and a flame-retardant short fiber coating layer. The functional layer comprises a plurality of layers of heat-insulating inorganic fiber coating layers and heat-conducting inorganic fiber coating layers. The number of layers of the functional layer is even, and the heat-insulating inorganic fiber coating layers and the heat-conducting inorganic fiber coating layers are arranged in a cross manner from inside to outside or sequentially from inside to outside as a plurality of layers of mowrah filament coating layers and a plurality of layers of heat-conducting inorganic fiber coating layers. The multi-layer fast heat-conducting high-temperature-resistant elastic yarn with good mechanical properties, high elastic elongation, excellent flame-retardant high-temperature-resistant performance is formed by the synergistic cooperation of a braiding machine or a wrapping spinning machine and a friction spinning machine. The yarn can be applied to the fields of fire hoses, fire suits, flame-retardant home textile products and the like, and has wide application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of spinning technology, in particular to a multi-layered quick heat-conducting high-temperature-resistant elastic yarn and a preparation method thereof. BACKGROUND

[0002] With the development of science and technology and the progress of society, high-performance textile materials have become a hot research topic. In the field of high-temperature-resistant fiber materials, various high-performance inorganic fibers are basically dominant. The best high-temperature-resistant organic fiber is aramid fiber, which can withstand a temperature of about 400℃. Inorganic fibers such as carbon fibers can withstand a temperature of more than 2000℃. Due to the high rigidity of inorganic fibers and other problems, their application range is limited, so developing organic fibers with better high-temperature-resistant performance has become a hot topic.

[0003] In the current research on high-temperature-resistant organic fibers and yarns, generally, a flame-retardant high-temperature-resistant coating is coated on the surface of the fiber to form a flame-retardant layer or a high-temperature-resistant yarn is prepared by blending flame-retardant organic fibers with original fibers. For example, the patent with publication number CN108396476A discloses a preparation process of high-temperature-resistant polyester yarn. 5%-15% of polytetrafluoroethylene, 1.5%-3.5% of crosslinking agent, 0.3%-0.8% of anti-aging agent, 4%-9% of anhydrous auxiliary agent, 0.2%-0.4% of defoaming agent, 1.8%-4.2% of catalyst and 55-80% of water are put into a blender to prepare a slurry, then the slurry is coated on the surface of polyester yarn through a sizing device, and then the sprayed polyester yarn is wound to obtain high-temperature-resistant polyester yarn. Although this method can change the organic polyester fiber that cannot withstand high temperature into a high-temperature-resistant polyester fiber, it has the problems of poor hand feeling of the yarn after coating and poor high-temperature-resistant performance, which cannot meet the use in some clothing and in some high-temperature environments.

[0004] The patent with publication number CN108251931A discloses a high-temperature-resistant blended yarn and a production process thereof. The invention includes an outer layer and a core layer, the outer layer is coated on the core layer, the outer layer includes a flame-retardant layer, an oil-proof layer and a skin polymer arranged from inside to outside, the core layer includes a main core yarn and a temperature-regulating viscose fiber twisted with the main core yarn, the main core yarn is formed by blending polyimide fiber and polyether ketone. The advantages of this invention are: excellent high-temperature-resistant performance and oil-proof performance, suitable for manufacturing oil-proof carpets for restaurants, practical and effective. However, the yarn cannot reach the level of inorganic fibers in terms of high-temperature-resistant performance.

[0005] Basalt fiber has good flame-retardant and heat-insulating properties in inorganic fibers, and its long-term working range is between-269 DEG C and 650 DEG C, and it can withstand high temperature up to 1300 DEG C for a short time, and is often used in some flame-retardant and heat-insulating scenes. Carbon fiber, as one of the most commonly used inorganic fibers, has excellent performance, high strength, light weight, good high-temperature resistance and good thermal conductivity. In order to improve the high-temperature resistance of organic fibers, a patent with publication number CN102154753A discloses a basalt wrapped yarn, which is prepared by winding a mixed yarn around the outer layer of basalt fiber to form a basalt fiber wrapped yarn. The yarn belongs to organic-inorganic composite yarn, which can greatly improve the high-temperature resistance of organic fibers; but since basalt fiber is used as core yarn, the overall yarn lacks elasticity and comfort, which is not conducive to the further application of the yarn. SUMMARY

[0006] In view of the technical problems in the background art, the present application provides a multi-layer quick heat-conducting high-temperature-resistant elastic yarn and a preparation method thereof. The heat-insulating inorganic fiber filaments and the heat-conducting inorganic fiber filaments are successively woven or wrapped on the surface of the elastic core yarn by using a knitting machine or a wrapping spinning machine to prepare an elastic composite core yarn, and then the flame-retardant short fibers are coated on the surface of the composite core yarn by using friction spinning to form an organic-inorganic composite multi-layer high-temperature-resistant yarn with stable structure, high strength and good high-temperature resistance, so as to make up for the defects of organic soft fibers that cannot resist flame and high temperature.

[0007] In a first aspect, the embodiments of the present application provide a multi-layer quick heat-conducting high-temperature-resistant elastic yarn, which comprises, from inside to outside, an elastic core yarn, a functional layer, and a flame-retardant short fiber coating layer.

[0008] The functional layer comprises a plurality of layers of heat-insulating inorganic fiber coating layers and heat-conducting inorganic fiber coating layers, the number of layers of the functional layer is an even number, and the heat-insulating inorganic fiber coating layers and the heat-conducting inorganic fiber coating layers are arranged in cross from inside to outside or successively from inside to outside as a plurality of layers of heat-insulating inorganic fiber coating layers and a plurality of layers of heat-conducting inorganic fiber coating layers.

[0009] In the technical solution of the embodiments of the present application, the heat-conducting inorganic fiber coating layer serves as a heat-conducting layer to quickly transfer and diffuse the heat of the high-temperature contact point, which can effectively reduce the temperature of the contact point, and the heat-insulating inorganic fiber coating layer serves as a heat-insulating layer to effectively block the transfer of the remaining heat to the internal elastic fiber when the heat is transferred to the heat-insulating inorganic fiber coating layer, thereby avoiding the destruction of the elastic fiber structure by high temperature and greatly improving the high-temperature resistance of the yarn as a whole.

[0010] In some embodiments, the number of layers of the functional layer is 2, and from inside to outside, the functional layer successively comprises a heat-insulating inorganic fiber coating layer and a heat-conducting inorganic fiber coating layer.

[0011] In this embodiment, the insulating inorganic fibers provide good high-temperature resistance and mechanical strength, while the heat-conducting inorganic fibers provide high thermal conductivity and lightweight properties. The two-layer structure is relatively simple, facilitating production and maintenance.

[0012] In some embodiments, the number of functional layers is 4, arranged from inside to outside as an insulating inorganic fiber coating layer, an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, and a heat-conducting inorganic fiber coating layer, or as an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, an insulating inorganic fiber coating layer, and a heat-conducting inorganic fiber coating layer.

[0013] In this embodiment, the functional layers are arranged as an insulating inorganic fiber coating layer, an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, and a heat-conducting inorganic fiber coating layer, with two layers of insulating fiber filaments enhancing the yarn's high-temperature resistance, and two layers of heat-conducting fibers enhancing the yarn's thermal conductivity. The symmetrical arrangement helps improve the yarn's overall stability and mechanical properties. Or the functional layers are arranged as an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, an insulating inorganic fiber coating layer, and a heat-conducting inorganic fiber coating layer. The alternating arrangement of each layer of material enables the yarn to have balanced performance in terms of high-temperature resistance and thermal conductivity, and the alternating structure helps the heat to be evenly conducted within the yarn.

[0014] In some embodiments, the number of functional layers is 6, arranged as 3 layers of insulating inorganic fiber coating layers and 3 layers of heat-conducting inorganic fiber coating layers, or as an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, an insulating inorganic fiber coating layer, and a heat-conducting inorganic fiber coating layer.

[0015] In this embodiment, the functional layers are arranged as 3 layers of insulating inorganic fiber coating layers and 3 layers of heat-conducting inorganic fiber coating layers, with more layers meaning higher high-temperature resistance and thermal conductivity performance. The clear layer distribution helps precisely control the yarn's performance. Or the functional layers are arranged as an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, an insulating inorganic fiber coating layer, a heat-conducting inorganic fiber coating layer, an insulating inorganic fiber coating layer, and a heat-conducting inorganic fiber coating layer. The alternating arrangement enables the yarn to have excellent performance in terms of high-temperature resistance and thermal conductivity while maintaining good mechanical properties. The multi-layer alternating structure helps optimize heat management, especially in complex thermal environments.

[0016] The use of insulating inorganic fiber filaments improves the yarn's stability and durability in high-temperature environments, and the addition of heat-conducting inorganic fibers enables the yarn to quickly conduct heat, making it suitable for applications that require heat dissipation. The multi-layer structure enhances the yarn's strength and elasticity, making it more suitable for environments with high mechanical loads. Through the combination and arrangement of different materials, the yarn can better manage heat conduction and distribution.

[0017] In some embodiments, the heat-insulating inorganic fiber filaments and the heat-conducting inorganic fiber filaments in the heat-insulating inorganic fiber coating layer and the heat-conducting inorganic fiber coating layer are woven on the elastic core yarn in a cross-weaving structure or wound on the elastic core yarn in a spiral winding structure; the linear density of the heat-insulating inorganic fiber filaments is 4 tex to 25 tex, and the heat-insulating inorganic fiber is basalt fiber or glass fiber; the linear density of the heat-conducting inorganic fiber filaments is 5 tex to 50 tex, and the heat-conducting inorganic fiber is one of carbon fiber, graphene fiber, silicon carbide ceramic fiber, boron nitride ceramic fiber and metal fiber; the flame-retardant short fiber in the flame-retardant short fiber coating layer is wrapped on the surface of the functional layer in a mutual embracing and winding manner to form a multi-level composite structure yarn; the elastic core yarn is one or more of spandex filaments, silica gel filaments and latex filaments, and the fineness of the elastic core yarn is 100D to 1000D; and the raw material of the flame-retardant short fiber coating layer is one or more of flame-retardant polyamide fiber, flame-retardant viscose, aramid fiber and polyimide fiber.

[0018] In this embodiment, the cross-weaving can increase the structural stability of the yarn, so that the yarn is not easy to deform when subjected to external force. The weaving structure helps to disperse the load and improve the overall mechanical properties of the yarn. The spiral winding makes the heat-insulating inorganic fiber filaments and the heat-conducting inorganic fiber filaments uniformly distributed on the elastic core yarn, which helps to improve the uniformity of the performance, and the spiral structure helps to conduct heat along the length direction of the yarn.

[0019] The linear density of the heat-insulating inorganic fiber filaments is 4 tex to 25 tex, which ensures that the yarn maintains strength and heat resistance without being too thick and heavy. The linear density of the heat-conducting inorganic fiber filaments is 5 tex to 50 tex, which helps to achieve the best heat-conducting performance and overall quality of the yarn. The mutual embracing and winding manner of the flame-retardant short fiber coating layer helps to improve the flame-retardant performance of the yarn and reduce the spread of flames during combustion. The multi-level composite structure improves the durability and safety of the yarn.

[0020] In a second aspect, the embodiments of the present application provide a preparation method of a multi-level quick heat-conducting high-temperature-resistant elastic yarn, including the following steps:

[0021] S1, obtaining the number of functional layers and the composition of the functional layers;

[0022] S2, wrapping the functional layers on the surface of the elastic core yarn by using a weaving machine or a wrapping spinning machine to obtain a heat-insulating inorganic fiber and heat-conducting inorganic fiber composite elastic core yarn;

[0023] S3, wrapping flame-retardant short fibers on the surface of the heat-insulating inorganic fiber and heat-conducting inorganic fiber composite elastic core yarn by using a friction spinning method to obtain a multi-level quick heat-conducting high-temperature-resistant elastic yarn.

[0024] In the technical solutions of the embodiments of the present application, the number of functional layers and the specific composition of each layer are determined according to the performance requirements of the final product, including the arrangement order and proportion of the heat-insulating inorganic fibers and the heat-conducting inorganic fibers, and the heat-insulating inorganic fibers and the heat-conducting inorganic fibers are woven or wrapped on the surface of the elastic core yarn by using a weaving machine or a wrap spinning machine, so that the yarn has the characteristics of rapid heat conduction and high-temperature resistance while maintaining elasticity. The flame-retardant short fibers are uniformly coated on the surface of the composite elastic core yarn by using the friction spinning technology, thereby increasing the flame-retardant performance of the yarn.

[0025] During the weaving process of the weaving mechanism, the basalt fibers and the carbon fibers move and output along the fly spindles, and there is no twisting effect in this process. During the wrapping process of the wrap spinning machine, the heat-insulating inorganic fibers and the heat-conducting inorganic fibers are spirally wrapped on the core yarn, and there is also no twisting effect in this process, which avoids the structural damage of the heat-insulating inorganic fibers and the heat-conducting inorganic fibers due to twisting and self-twisting, thereby greatly improving the mechanical properties of the yarn. A layer of flexible flame-retardant short fibers is coated on the surface of the yarn by using the friction spinning technology, and the core yarn will not generate twist during the coating process, so the heat-insulating inorganic fibers and the heat-conducting inorganic fibers will not be structurally damaged, thereby ensuring the mechanical properties of the yarn. Meanwhile, the coating of the flexible flame-retardant short fibers provides protection for the composite core yarn, thereby improving the softness, wear resistance and skin-friendliness of the yarn.

[0026] In some embodiments, the step S2 includes the following operation steps:

[0027] The elastic core yarn is unwound from the first yarn tube, fed into the core yarn feeding roller of the weaving machine, passes through the guide tube and the guide roller, and is fed out from the first output roller. The functional layer yarn tube is installed on the fly spindle of the weaving machine. During spinning, the heat-insulating inorganic fiber filaments or the heat-conducting inorganic fiber filaments of the functional layer on the yarn tube of the fly spindle are unwound, interlaced on the surface of the elastic core yarn, and form a sheath-core structure. Then, the sheath-core structure is wound on the yarn drum through the output roller, thereby obtaining the elastic woven core yarn.

[0028] According to the number of functional layers and the composition of the functional layers in S1, the type of the functional layer yarn tube is changed, and the above steps are repeated to obtain the heat-insulating inorganic fiber and heat-conducting inorganic fiber composite elastic woven core yarn.

[0029] In this embodiment, the heat-insulating inorganic fiber filaments and the heat-conducting inorganic fiber filaments can effectively enhance the heat conductivity and high-temperature resistance of the elastic core yarn through interlaced weaving. The formation of the sheath-core structure improves the structural stability of the yarn, so that the yarn is not easy to deform when subjected to external force. The weaving process enables the yarn to maintain elasticity while also obtaining additional mechanical strength. By adjusting the number of functional layers and the composition, the performance of the yarn can be accurately customized to meet the needs of different applications.

[0030] In some embodiments, the speed of the core yarn feeding roller is 2-6 m / min, the speed of the traveler is 30-500 r / min, the speed of the yarn output roller is 4-18 m / min, and the draft ratio of the core yarn is 1-2.

[0031] In this embodiment, controlling the feeding speed helps to ensure the stability of the elastic core yarn during weaving, reducing yarn breakage and tension problems. Adjusting the speed of the traveler can control the weaving density of the thermal or heat-conducting inorganic fiber filaments on the elastic core yarn, thereby affecting the thermal conductivity and high-temperature resistance of the yarn. Higher speed can improve production efficiency, but too high speed may cause excessive yarn tension or unstable weaving, so it needs to be adjusted within a reasonable range. The speed of the output roller needs to match the weaving speed to ensure that the yarn does not be too tense or loose during winding. Proper winding speed helps to maintain the structure and performance of the yarn and avoid defects during winding. The draft ratio determines the degree of extension of the elastic core yarn during weaving, thereby affecting the elasticity and recovery ability of the final yarn. Proper draft can enhance the structural strength of the yarn, but excessive draft may cause yarn damage.

[0032] By pre-stretching the elastic core yarn during weaving, the thermal or heat-conducting inorganic fiber filaments are woven on the surface of the stretched elastic core yarn, resulting in an elastic woven yarn that can be stretched and retracted, making the yarn have good elasticity.

[0033] In some embodiments, the step S2 includes the following operation steps:

[0034] The elastic core yarn is unwound from the second yarn tube and fed into the feeding roller of the wrap spinning machine. The thermal or heat-conducting inorganic fiber filaments in the functional layer on the hollow tube are spirally wound on the surface of the elastic core yarn, and finally the elastic wrap core yarn is obtained by winding.

[0035] According to the number of layers and composition of the functional layer in S1, the type of the functional layer yarn tube is changed, and the above steps are repeated to obtain a thermal or heat-conducting inorganic fiber composite elastic wrap core yarn.

[0036] In this embodiment, the spiral winding method can uniformly wrap the functional layer on the elastic core yarn, thereby providing uniform heat conduction and high-temperature resistance. The spiral structure helps to improve the structural stability of the yarn, making it more durable when subjected to external forces. By changing the type of the functional layer yarn tube, the number of layers and composition of the functional layer can be easily adjusted to meet different application requirements.

[0037] In some embodiments, the core yarn feeding roller speed of the wrap spinning machine is 2.5-10 m / min, the yarn output roller speed is 5-20 m / min, the hollow spindle rotation speed is 2000-8000 r / min, and the core yarn draft ratio is 1-2 times.

[0038] In this embodiment, the feeding speed helps to ensure the stability of the elastic core yarn during the wrapping process and reduce yarn breakage and tension problems. The speed of the output roller needs to match the wrapping speed to ensure that the yarn does not become overly tense or loose during the winding process. The adjustment of the hollow spindle rotation speed can control the wrapping density of the thermal insulation inorganic fiber or heat-conducting inorganic fiber filament on the elastic core yarn, thereby affecting the thermal conductivity and high-temperature resistance of the yarn. The draft ratio determines the degree of extension of the elastic core yarn during the wrapping process, thereby affecting the elasticity and recovery ability of the final yarn. Proper draft ratio can enhance the structural strength of the yarn, but excessive draft may cause yarn damage.

[0039] In some embodiments, the step S3 includes the following operation steps:

[0040] The thermal insulation inorganic fiber and heat-conducting inorganic fiber composite elastic woven core yarn is unwound from the third bobbin, fed into the friction spun core yarn feeding roller, passes through the wedge-shaped groove formed by the two dust cages, and the flame-retardant staple fiber sliver is fed into the carding roller through the feeding roller. The loose fibers after carding are wrapped on the surface of the composite core yarn by the action of negative pressure suction and the friction force of the dust cage, forming a multi-level fast heat-conducting and high-temperature-resistant elastic yarn, and finally outputted through the third output roller and wound on the fourth bobbin.

[0041] In this embodiment, through the friction spinning technology, the flame-retardant staple fiber can be uniformly wrapped on the surface of the composite elastic woven core yarn, forming a multi-level structure, and improving the flame-retardant performance and high-temperature resistance of the yarn. The friction spinning technology provides an efficient wrapping process, reduces the production time, and improves the production efficiency. Through the action of negative pressure suction and the friction force of the dust cage, the wrapping density and uniformity of the flame-retardant staple fiber can be accurately controlled, thereby ensuring the consistency of the yarn quality.

[0042] In some embodiments, the speed of the friction spun core yarn feeding roller is 2-5 m / min, the feeding speed of the flame-retardant staple fiber sliver is 0.5-2 m / min, the rotation speed of the flame-retardant staple fiber carding roller is 2000-4000 r / min, the rotation speed of the friction roller connected to the dust cage is 2500-5000 r / min, the speed of the third output roller is 3-10 m / min, and the winding speed of the bobbin is 3.2-12 m / min.

[0043] In this embodiment, the feed speed helps to ensure the stability of the composite elastic woven core yarn during the friction spinning process, reducing the problem of broken ends and tension. The speed adjustment of the carding roller can control the carding effect of the flame-retardant short fibers, thereby affecting the covering density and uniformity of the yarn. The speed adjustment of the friction roller can control the friction force between the flame-retardant short fibers and the dust cage, thereby affecting the covering effect of the yarn. The speed of the output roller needs to be matched with the friction spinning process to ensure that the yarn does not be too tense or loose during winding. The adjustment of the winding speed can control the winding effect of the yarn on the bobbin, thereby affecting the structure and performance of the yarn.

[0044] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the following specific embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0046] Figure 1 Structure diagram of the multi-level rapid heat-conducting high-temperature-resistant elastic yarn prepared in Embodiment 1 of the present application;

[0047] Figure 2 Structure diagram of the multi-level rapid heat-conducting high-temperature-resistant elastic yarn prepared in Embodiment 1 of the present application;

[0048] Figure 3 Structure diagram of the braiding machine in the preparation method of the multi-level rapid heat-conducting high-temperature-resistant elastic yarn of the present application;

[0049] Figure 4 Structure diagram of the wrap spinning machine in the preparation method of the multi-level rapid heat-conducting high-temperature-resistant elastic yarn of the present application;

[0050] Figure 5 Structure diagram of the friction spinning machine in the preparation method of the multi-level rapid heat-conducting high-temperature-resistant elastic yarn of the present application;

[0051] Figure 6 Actual photo of the multi-level rapid heat-conducting high-temperature-resistant elastic yarn prepared in Embodiment 1 of the present application.

[0052] Explanation of reference signs:

[0053] 1. Multilayer fast heat-conducting high-temperature-resistant elastic yarn; 11. Elastic core yarn; 12. Thermal insulation inorganic fiber coating layer; 13. Heat-conducting inorganic fiber coating layer; 14. Flame-retardant short fiber coating layer;

[0054] 2. Braiding machine; 21. First yarn tube; 22. Core yarn feeding roller; 23. Braiding machine traveler; 24. Guide tube; 25. Guide wheel; 26. First output roller; 27. Yarn drum;

[0055] 3. Wrap spinning machine; 31. Feeding roller; 32. Second yarn tube; 33. Wrap spinning machine feeding roller; 34. Hollow spindle; 35. Hollow tube; 36. Second output roller; 37. Guide ring; 38. Winding mechanism;

[0056] 4. Friction spinning machine; 41. Yarn rack; 42. Third yarn tube; 43. Friction spinning core yarn feeding roller; 44. Dust cage; 45. Splitting roller; 46. Flame-retardant short fiber feeding roller; 47. Third output roller; 48. Fourth yarn tube. DETAILED DESCRIPTION

[0057] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0059] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0060] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0061] In the description of the embodiments of the present application, the term "and / or" is merely to describe an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing alone, A and B existing together, and B existing alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.

[0062] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0063] In the prior art, due to the high rigidity of basalt fibers and carbon fibers, the yarn prepared by the existing method has low strength, poor high-temperature resistance and poor flame retardant effect.

[0064] In order to solve the technical problem that the organic composite fiber cannot be flame-retardant and high-temperature-resistant, the present application provides a multi-level rapid heat-conducting high-temperature-resistant elastic yarn 1 and a preparation method thereof, wherein the elastic core yarn 11, the functional layer and the flame-retardant short fiber coating layer 14 are arranged from inside to outside, so as to achieve the technical effects of improving elasticity, high-temperature resistance and flame retardant performance.

[0065] Please refer to Figures 1 to 2 , in a first aspect, the present application provides a multi-level rapid heat-conducting high-temperature-resistant elastic yarn 1, which comprises an elastic core yarn 11, a functional layer and a flame-retardant short fiber coating layer 14 from inside to outside; the functional layer comprises a plurality of layers of heat-insulating inorganic fiber coating layer 12 and heat-conducting inorganic fiber coating layer 13, the number of layers of the functional layer is an even number, and the heat-insulating inorganic fiber coating layer 12 and the heat-conducting inorganic fiber coating layer 13 are arranged in cross from inside to outside or sequentially from inside to outside as a plurality of layers of heat-insulating inorganic fiber coating layer 12 and a plurality of layers of heat-conducting inorganic fiber coating layer 13.

[0066] Due to the use of the heat-conducting inorganic fiber coating layer 13, the heat-conducting inorganic fiber has very high thermal conductivity, can rapidly conduct heat, and ensures that the yarn still has a low linear expansion coefficient under high-temperature environment, maintaining dimensional stability. The combination of the heat-insulating inorganic fiber coating layer 12 and the heat-conducting inorganic fiber coating layer 13 provides excellent high-temperature resistance. The heat-insulating inorganic fiber itself has good heat resistance and can maintain structural stability under high-temperature environment and is not easy to soften or melt. The arrangement of the elastic core yarn 11 enables the yarn to maintain a certain elasticity when subjected to high temperature and mechanical stress, increasing the comfort and durability of the yarn. The flame-retardant short fiber coating layer 14 is at the outermost layer of the yarn, which can effectively improve the flame retardance of the yarn, reduce the flame propagation speed, and improve the safety during use.

[0067] The number of layers of the functional layer is designed as an even number, and the thermal insulation inorganic fiber covering layer 12 and the heat conduction inorganic fiber covering layer 13 are arranged in cross or sequentially arranged, which enhances the comprehensive performance of the yarn, such as mechanical properties and thermal stability, and makes it more suitable for use in high temperature environment.

[0068] Further, in some embodiments, the number of layers of the functional layer is 2, and from inside to outside, it is sequentially arranged as the thermal insulation inorganic fiber covering layer 12 and the heat conduction inorganic fiber covering layer 13; or, the number of layers of the functional layer is 4, and from inside to outside, it is sequentially arranged as the thermal insulation inorganic fiber covering layer 12, the thermal insulation inorganic fiber covering layer 12, the heat conduction inorganic fiber covering layer 13 and the heat conduction inorganic fiber covering layer 13, or sequentially arranged as the thermal insulation inorganic fiber covering layer 12, the heat conduction inorganic fiber covering layer 13, the thermal insulation inorganic fiber covering layer 12 and the heat conduction inorganic fiber covering layer 13; or, the number of layers of the functional layer is 6, and from inside to outside, it is sequentially arranged as 3 layers of the thermal insulation inorganic fiber covering layer 12 and 3 layers of the heat conduction inorganic fiber covering layer 13, or sequentially arranged as the thermal insulation inorganic fiber covering layer 12, the heat conduction inorganic fiber covering layer 13, the thermal insulation inorganic fiber covering layer 12, the heat conduction inorganic fiber covering layer 13, the thermal insulation inorganic fiber covering layer 12 and the heat conduction inorganic fiber covering layer 13.

[0069] In the technical scheme of the embodiments of the present application, by adjusting the number of layers and the order of materials, the heat conductivity, high temperature resistance, flame retardancy and elasticity of the yarn can be balanced. Different number of layers and composition design can meet different application requirements, such as high temperature work clothes, fireproof materials, thermal management, etc. By accurately controlling the number of layers and the composition of materials, the overall performance of the yarn can be optimized to meet the requirements of specific applications.

[0070] Further, in some embodiments, the thermal insulation inorganic fiber filaments and the heat conduction inorganic fiber filaments in the thermal insulation inorganic fiber covering layer 12 and the heat conduction inorganic fiber covering layer 13 are woven on the elastic core yarn 11 in a cross weaving structure or wound on the elastic core yarn 11 in a spiral winding structure; the linear density of the thermal insulation inorganic fiber filaments is 4tex-25tex, and the thermal insulation inorganic fiber is basalt fiber or glass fiber; the linear density of the heat conduction inorganic fiber filaments is 5tex-50tex, and the heat conduction inorganic fiber is one of carbon fiber, graphene fiber, silicon carbide ceramic fiber, boron nitride ceramic fiber and metal fiber; the flame-retardant short fiber in the flame-retardant short fiber covering layer 14 is wrapped on the surface of the composite core yarn in a mutual entwining manner to form a multi-level composite structure yarn; the elastic core yarn 11 is one or more of spandex filaments, silica gel filaments and latex filaments, and the fineness of the elastic core yarn 11 is 100D-1000D; the raw material of the flame-retardant short fiber covering layer 14 is one or more of flame-retardant polyamide, flame-retardant viscose, aramid fiber and polyimide fiber.

[0071] In the technical scheme of the embodiment of the present application, the cross weaving can enhance the structural stability and mechanical properties of the yarn; the spiral winding can provide uniform thermal conductivity and high temperature resistance while maintaining the elasticity of the yarn; the selection of the thermal insulation inorganic fiber filament linear density range ensures that the yarn maintains strength and heat resistance without being too thick and heavy; the selection of the thermal conductive inorganic fiber filament linear density helps to achieve the best thermal conductivity performance and overall quality of the yarn. The mutual entwining and winding mode helps to improve the flame retardant performance of the yarn and reduce the spread of flames during combustion. The multi-level composite structure improves the durability and safety of the yarn.

[0072] The elastic core yarn 11 selects spandex filament, silica gel filament and latex filament, which provide the required elasticity of the yarn to enable it to restore to its original state after stretching. The raw materials of the flame-retardant short fiber coating layer 14 are flame-retardant nylon, flame-retardant viscose, aramid fiber and polyimide fiber, which have excellent flame-retardant properties and help to improve the safety performance of the yarn.

[0073] Please refer to Figures 3 to 5 , in a second aspect, the embodiment of the present application provides a preparation method of a multi-level rapid heat-conducting high-temperature-resistant elastic yarn 1, comprising the following steps:

[0074] S1, obtaining the number of functional layers and the composition of the functional layers;

[0075] S2, wrapping the functional layers on the surface of the elastic core yarn 11 by using a weaving machine 2 or a wrapping spinning machine 3 to obtain a carbon fiber and basalt fiber composite elastic core yarn;

[0076] S3, wrapping the flame-retardant short fibers on the surface of the carbon fiber and basalt fiber composite elastic core yarn by using a friction spinning method to obtain a multi-level rapid heat-conducting high-temperature-resistant elastic yarn 1.

[0077] Among them, through different functional layers, the multi-level optimization of the yarn in terms of thermal conductivity, high temperature resistance and flame retardancy is realized. The selection and combination of the thermal insulation inorganic fiber filament, the thermal conductive inorganic fiber filament and the flame-retardant short fiber make the yarn maintain performance at extreme temperatures, ensure the uniform wrapping of the functional layers and the formation of the composite elastic core yarn, and improve the performance and structural stability of the yarn. The friction spinning technology provides an efficient wrapping process while maintaining the uniformity of the flame-retardant short fibers and the structural integrity of the yarn.

[0078] Further, in some embodiments, step S2 comprises the following operation steps:

[0079] The elastic core yarn 11 is unwound from the first yarn tube 21, fed from the core yarn feeding roller 22 of the knitting machine 2, passes through the guide tube 24, passes through the guide roller 25, and is fed out from the first output roller 26. The functional layer yarn tube is installed on the walking spindle 23 of the knitting machine. The heat-insulating inorganic fiber filaments or heat-conducting inorganic fiber filaments of the functional layer on the yarn tube of the walking spindle are unwound during spinning, interlaced on the surface of the elastic core yarn 11, form a core-skin structure, and are wound on the yarn drum 27 through the output winding mechanism 38 to obtain the elastic knitting core yarn.

[0080] According to the number of layers of the functional layer and the composition of the functional layer in S1, the type of the functional layer yarn tube is changed, and the above steps are repeated to obtain the elastic knitting core yarn with heat-insulating inorganic fiber and heat-conducting inorganic fiber. The speed of the core yarn feeding roller 22 is 2-6 m / min, the speed of the walking spindle is 30-500 r / min, the speed of the first output roller 26 is 4-18 m / min, and the draft ratio of the core yarn is 1-2.

[0081] In the technical scheme of the embodiment of the present application, the guide tube 24 and the guide roller 25 help to control the movement of the yarn and maintain the stability of the knitting process. The rotation of the walking spindle enables the heat-insulating inorganic fiber filaments or heat-conducting inorganic fiber filaments of the functional layer to be uniformly unwound and interlaced on the elastic core yarn 11, and the interlaced knitting forms a core-skin structure, which enhances the structural stability and mechanical properties of the yarn. The elastic core yarn 11 serves as the core, and the functional layer serves as the skin. This structure helps to improve the comprehensive performance of the yarn, such as heat conductivity, high-temperature resistance, and elasticity.

[0082] Further, in some embodiments, step S2 includes the following operation steps:

[0083] The elastic core yarn 11 is unwound from the second yarn tube 32 through the feeding roller 31 of the wrap spinning machine 3, fed from the wrap spinning machine feeding roller 33, output from the second output roller 36 through the hollow spindle 34, and finally wound through the guide ring 37 and the winding mechanism 38 to obtain the elastic wrap core yarn.

[0084] According to the number of layers of the functional layer and the composition of the functional layer in S1, the type of the functional layer yarn tube is changed, and the above steps are repeated to obtain the elastic knitting core yarn with heat-insulating inorganic fiber and heat-conducting inorganic fiber. The speed of the core yarn feeding roller 22 is 2-6 m / min, the speed of the walking spindle is 30-500 r / min, the speed of the first output roller 26 is 4-18 m / min, and the draft ratio of the core yarn is 1-2.

[0085] In the technical scheme of the embodiment of the present application, the heat-insulating inorganic fiber filament or the heat-conducting inorganic fiber filament of the functional layer is wound in a spiral form on the surface of the elastic core yarn 11 to form a multi-level structure, and the winding mode improves the comprehensive performance of the yarn, such as heat conductivity, high-temperature resistance and elasticity. Through the mechanical operation steps, the stability of the production process and the consistency of the yarn quality are ensured. The prepared yarn has wide adaptability and can be used in various industrial and technological fields, such as aerospace, high-temperature work clothes, thermal management and the like.

[0086] Further, in some embodiments, step S3 comprises the following operation steps:

[0087] The heat-conducting inorganic fiber and the heat-insulating inorganic fiber composite elastic woven core yarn are unwound from the third yarn tube 42, fed into the friction spinning core yarn feeding roller 43, pass through the wedge-shaped groove formed by the two dust cages 44, the flame-retardant short fiber sliver enters the carding roller 45 through the flame-retardant short fiber feeding roller 46, the scattered fibers after carding are coated on the surface of the composite core yarn through the action of negative pressure suction and the friction force of the dust cage 44 to form a multi-level fast heat-conducting high-temperature-resistant elastic yarn 1, and finally output through the third output roller 47 and wound on the fourth yarn tube 48. The third yarn tube 42 is located on the creel 41 of the friction spinning machine 4, the speed of the friction spinning core yarn feeding roller 43 is 2-5 m / min, the feeding speed of the flame-retardant short fiber sliver is 0.5-2 m / min, the rotating speed of the carding roller 45 is 2000-4000 r / min, the rotating speed of the friction roller connected with the dust cage 44 is 2500-5000 r / min, the speed of the third output roller 47 is 3-10 m / min, and the winding speed of the yarn drum is 3.2-12 m / min.

[0088] In the technical scheme of the embodiment of the present application, through the friction spinning technology, the flame-retardant short fibers can be uniformly coated on the surface of the composite elastic woven core yarn to form a multi-level structure, and the flame-retardant performance and the high-temperature resistance of the yarn are improved.

[0089] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application. If the specific technology or condition is not specified in the examples, the technology or condition described in the literature in the art or according to the product manual is used. If the reagent or instrument is not specified by the manufacturer, it is a conventional product that can be obtained by purchase.

[0090] I. Preparation method

[0091] Example 1

[0092] The embodiment provides a preparation method of a multi-level quick heat-conducting high-temperature-resistant elastic yarn 1. The elastic core yarn 11 is a 100D silica gel filament, the basalt fiber has a linear density of 8tex, the carbon fiber has a linear density of 15tex, and the composition of the flame-retardant staple fiber is flame-retardant polyamide fiber / flame-retardant viscose fiber / aramid fiber blended fiber. The method specifically comprises the following steps:

[0093] S1, the silica gel filament is unwound from the first yarn pipe 21 and fed into the core yarn feeding roller 22 of the braiding machine 2, passes through the guide pipe 24, passes through the guide wheel 25, is fed out from the first output roller 26, the basalt fiber yarn pipe is installed on the braiding machine gallop spindle 23, and the basalt fiber on the gallop spindle yarn pipe is unwound during spinning and is interlaced on the surface of the elastic core yarn 11 to form a skin-core structure, and then is wound on the yarn drum 27 through the output to obtain the basalt elastic braided core yarn.

[0094] The speed of the core yarn feeding roller 22 is 3m / min, the rotating speed of the braiding machine gallop spindle 23 is 200r / min, the speed of the first output roller 26 is 6m / min, and the draft ratio of the core yarn is 2 times.

[0095] S2, the basalt elastic braided core yarn in step S1 is unwound from the first yarn pipe 21 and fed into the core yarn feeding roller 22 of the braiding machine, passes through the guide pipe 24, passes through the guide wheel 25, is fed out from the first output roller 26, the carbon fiber yarn pipe is installed on the braiding machine gallop spindle 23, and the carbon fiber on the gallop spindle yarn pipe is unwound during spinning and is interlaced on the surface of the basalt elastic core yarn, and then is wound to obtain the carbon fiber and basalt fiber composite elastic braided core yarn through the output.

[0096] The speed of the core yarn feeding roller 22 is 3m / min, the rotating speed of the braiding machine gallop spindle 23 is 200r / min, the speed of the first output roller 26 is 6m / min, and the draft ratio of the core yarn is 2 times.

[0097] S3, the carbon fiber and basalt fiber composite elastic braided core yarn in step S2 is unwound from the third yarn pipe 42, is fed into the friction spinning core yarn feeding roller 43, passes through the wedge-shaped groove formed by the two dust cages 44, the flame-retardant staple fiber sliver enters the carding roller 45 through the flame-retardant staple fiber feeding roller 46, the scattered fibers after carding are wrapped on the surface of the composite core yarn through the friction force of the dust cage 44 and the negative pressure air suction to form the multi-level quick heat-conducting high-temperature-resistant elastic yarn 1, and finally is output through the third output roller 47 and is wound on the fourth yarn pipe 48.

[0098] Wherein, the friction spinning core yarn feeding roller 43 speed is 5 m / min, the flame-retardant short fiber coarse strip feeding speed is 0.8 m / min, the flame-retardant short fiber carding roller 45 rotating speed is 3500 r / min, the connecting dust cage 44 friction roller rotating speed is 4000 r / min, the third output roller 47 speed is 10 m / min, and the yarn drum winding speed is 12 m / min.

[0099] Referring to the structure diagram of the multi-level quick heat-conducting high-temperature-resistant elastic yarn 1 shown in Figure 1 and Figure 2 , it can be seen that the yarn is composed of four layers of structures, wherein the first layer is an elastic core yarn 11, which plays a role of elastic stretching; the second layer is a heat-insulating inorganic fiber covering layer 12, which plays a role of flame retardation and heat insulation; the third layer is a heat-conducting inorganic fiber covering layer 13, which plays a role of flame retardation and quickly conducting away the heat of the high-temperature contact point, thereby reducing the temperature of the point; and the fourth layer is a flame-retardant short fiber covering layer 14, which can play a role of improving wear resistance, skin-friendliness and softness. The actual picture of the prepared multi-level quick heat-conducting high-temperature-resistant elastic yarn 1 is shown in Figure 6 .

[0100] Example 2

[0101] The embodiment provides a preparation method of a multi-level quick heat-conducting high-temperature-resistant elastic yarn 1. The elastic core yarn 11 used is a 200D silica gel filament, the basalt fiber has a linear density of 8 tex, the carbon fiber filament has a linear density of 15 tex, and the flame-retardant short fiber is a flame-retardant polyamide / flame-retardant viscose / aramid blended fiber. Compared with example 1, the difference lies in that the spinning mode used in example 2 is wrap spinning, and the basalt filament and the carbon fiber filament are spirally wound on the surface of the elastic core yarn 11, so as to obtain greater tensile properties. Specifically, the following steps are included.

[0102] S1, the elastic core yarn 11 is unwound from the second yarn pipe 32 and fed into the wrap spinning machine feeding roller 33, and then output from the second output roller 36 through the hollow spindle 34, wherein the basalt filament on the hollow pipe 35 is spirally wound on the surface of the elastic core yarn 11, and finally wound through the winding mechanism 38 to obtain a basalt elastic wrap core yarn.

[0103] Wherein, the wrap spinning machine feeding roller 33 speed is 2.5 m / min, the second output roller 36 speed is 5 m / min, the hollow spindle 34 rotating speed is 5000 r / min, and the core yarn draft ratio is 2 times.

[0104] S2, the basalt elastic wrapping core yarn is unwound from the second yarn tube 32, fed into the feeding roller 33 of the wrapping spinning machine, output from the second output roller 36 through the hollow spindle 34, and finally wound to obtain the basalt carbon fiber elastic wrapping core yarn through the winding mechanism 38.

[0105] The speed of the feeding roller 33 of the wrapping spinning machine is 2.5 m / min, the speed of the second output roller 36 is 5 m / min, the rotating speed of the hollow spindle 34 is 5000 r / min, and the draft ratio of the core yarn is 2 times.

[0106] S3, the basalt carbon fiber elastic wrapping core yarn in step S2 is unwound from the third yarn tube 42, fed into the friction spun core yarn feeding roller 43, and then passed through the wedge-shaped groove formed by the two dust cages 44. The flame-retardant short fiber sliver is fed into the flame-retardant short fiber feeding roller 46 and then into the carding roller 45. The scattered fibers after carding are wrapped on the surface of the composite core yarn through the friction force between the dust cage 44 and the negative pressure air suction, to form the multi-layer fast heat-conducting high-temperature-resistant elastic yarn 1. Finally, the yarn is output through the third output roller 47 and wound on the fourth yarn tube 48.

[0107] The speed of the friction spun core yarn feeding roller 43 is 5 m / min, the speed of the flame-retardant short fiber feeding roller 46 is 0.8 m / min, the rotating speed of the flame-retardant short fiber carding roller 45 is 3500 r / min, the rotating speed of the friction roller connected to the dust cage 44 is 4000 r / min, the speed of the third output roller 47 is 10 m / min, and the winding speed of the yarn drum is 12 m / min.

[0108] Example 3

[0109] The embodiment provides a preparation method of the multi-layer fast heat-conducting high-temperature-resistant elastic yarn 1. Compared with example 1, the difference lies in that the elastic silica gel filament is woven with basalt fibers through two steps S1 and then woven with carbon fibers through two steps S2, to obtain a composite core yarn with a four-layer weaving structure. The rest is substantially the same as example 1, and details are not repeated here.

[0110] Example 4

[0111] The embodiment provides a preparation method of the multi-layer fast heat-conducting high-temperature-resistant elastic yarn 1. Compared with example 1, the difference lies in that the elastic silica gel filament is woven with basalt fibers and carbon fibers through steps S1 and S2, and then the steps S1 and S2 are repeated once, to obtain a composite core yarn with a four-layer weaving structure. The rest is substantially the same as example 1, and details are not repeated here.

[0112] Example 5

[0113] The embodiment provides a preparation method of the multi-level quick heat-conducting high-temperature-resistant elastic yarn 1. Compared with the embodiment 1, the difference lies in that the elastic silica gel filament is knitted with basalt fibers three times according to steps S1 and S2, and then is knitted with carbon fibers three times according to step S2, so that a composite core yarn with a six-layer knitted structure is obtained, and the rest is basically the same as the embodiment 1, and details are not repeated here.

[0114] Embodiment 6

[0115] The embodiment provides a preparation method of the multi-level quick heat-conducting high-temperature-resistant elastic yarn 1. Compared with the embodiment 1, the difference lies in that the elastic silica gel filament is knitted with basalt fibers three times according to steps S1 and S2, and then is knitted with carbon fibers three times according to step S2, so that a composite core yarn with a six-layer knitted structure is obtained, and the rest is basically the same as the embodiment 1, and details are not repeated here.

[0116] Comparative Example 1

[0117] Comparative Example 1 is different from the embodiment 1 in that the knitted steps S1 and S2 are not performed, and the silica gel filament is directly coated with the flame-retardant short fibers according to step S3.

[0118] Comparative Example 2

[0119] Comparative Example 2 is different from the embodiment 1 in that the step S1 of knitting the carbon fiber layer is not performed, and the basalt fibers are directly knitted on the surface of the elastic silica gel, and then the step S3 of coating the flame-retardant short fibers is performed.

[0120] Comparative Example 3

[0121] Comparative Example 3 is different from the embodiment 1 in that the step S2 of knitting the basalt fibers is not performed, and the composite core yarn knitted with the carbon fiber layer is directly coated with the flame-retardant short fibers according to step S3.

[0122] II. Test method

[0123] 1. Strength and elongation at break test

[0124] Test method: The yarn is clamped vertically at both ends on a strength tensile tester, and is stretched until the yarn is completely broken, so that the strength and elongation at break of the yarn are tested. Test instrument: Instron strength tensile tester, stretching speed: 100 mm / min, clamping length: 100 mm, environmental temperature: 25 DEG C, environmental humidity: 50%.

[0125] 2. Flame-retardant performance test

[0126] Test method: The test yarn sample was clamped horizontally by a stand, and the yarn sample was continuously burned by alcohol lamp flame until it burned and broke, and the time from the beginning of burning to the burning and breaking was calculated, that is, the flame retardant time of the yarn sample. Test instrument: stand, alcohol lamp, clamping length: 100 mm, flame temperature: 500-600℃, ambient temperature: 25℃, ambient humidity: 50%.

[0127] The test results are shown in Tables 1 and 2.

[0128] Table 1 Performance test results of yarns prepared in Example 1 and Comparative Examples 1-3

[0129] Item Force (cN) Elongation at break (%) Flame retardant time (s) Example 1 3682.5 156.4 20.3 Comparative Example 1 362.3 369.7 2.6 Comparative Example 2 1569.3 143.9 9.8 Comparative Example 3 2135.8 162.4 6.1

[0130] Table 2 Performance test results of yarns prepared in Examples 2-6

[0131] Item Force (cN) Elongation at break (%) Flame retardant time (s) Example 2 5836.4 235.4 32.6 Example 3 6325.1 132.6 34.6 Example 4 6435.8 145.9 35.1 Example 5 8536.1 124.6 46.2 Example 6 8125.9 119.6 47.9

[0132] III. Analysis of test results of each example and comparative example

[0133] As shown in Table 1, compared with Comparative Examples 1-3, the strength of the multi-layered rapid heat-conducting high-temperature-resistant elastic yarn 1 prepared in Example 1 is much higher than that of the three yarns of Comparative Examples 1-3, the elongation at break is not much different from that of Comparative Examples 2 and 3, and lower than that of Comparative Example 1, and the flame retardant performance is better than that of the three yarns of Comparative Examples 1-3, which indicates that the yarn prepared by the method of the application has higher strength and is more suitable for application environments with greater mechanical stress, although the elongation at break is slightly lower, it still maintains a certain elasticity and is suitable for applications that require a certain flexibility, and the excellent flame retardant performance makes it more suitable for applications in high-temperature or flammable environments, such as high-temperature industries, fire-fighting equipment, etc.

[0134] As shown in Table 2, with the increase of the number of braiding layers, the strength of Examples 3-6 increases, the elongation at break slightly decreases, and the flame retardant time increases with the increase of the number of layers. As shown in Example 2, the tensile properties of the yarn with wrapping structure are better than those of the yarn with braiding structure, which indicates that the structure (braiding or wrapping) of the yarn of the application significantly affects its mechanical properties and flame retardant properties, increasing the number of braiding layers can improve the strength and flame retardant properties of the yarn, and the yarn with wrapping structure is better than the yarn with braiding structure in terms of tensile properties, which may be due to the fact that the wrapping structure provides better fiber arrangement and stress distribution, thereby maintaining the strength of the yarn while improving its tensile properties.

[0135] Note that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration, function, and effect as the technical idea of the present application are included in the technical scope of the present application. Furthermore, other modes constructed by applying various modifications to the embodiments, or by combining part of the configurations of the embodiments, which can be conceived by those skilled in the art, without departing from the spirit of the present application, are also included in the scope of the present application.

Claims

1. A multi-layered, high-temperature resistant, heat-conducting, multi-level elastic yarn, characterized in that, From the inside out, it consists of an elastic core yarn, a functional layer, and a flame-retardant short fiber coating layer; The functional layer includes several layers of thermal insulation inorganic fiber covering layer and thermal conductive inorganic fiber covering layer. The number of functional layers is even. The thermal insulation inorganic fiber covering layer and the thermal conductive inorganic fiber covering layer are arranged in a cross pattern from the inside to the outside or are arranged sequentially from the inside to the outside as several layers of thermal insulation inorganic fiber covering layer and several layers of thermal conductive inorganic fiber covering layer. The thermal insulation inorganic fiber covering layer and the thermally conductive inorganic fiber covering layer are woven into the elastic core yarn in a cross-weave structure or wound into the elastic core yarn in a spiral winding structure. The flame-retardant short fibers in the flame-retardant short fiber coating layer are wrapped around the surface of the functional layer in a mutually entangled manner, forming a multi-level composite structure yarn.

2. The multi-layered, high-temperature resistant, and rapidly thermally conductive elastic yarn according to claim 1, characterized in that, The functional layer has two layers, consisting of a thermal insulation inorganic fiber coating layer and a thermally conductive inorganic fiber coating layer from the inside out. Alternatively, the functional layer has four layers, which are, from the inside out, a thermal insulation inorganic fiber covering layer, a thermal insulation inorganic fiber covering layer, a thermally conductive inorganic fiber covering layer, and a thermally conductive inorganic fiber covering layer, or in the order of a thermal insulation inorganic fiber covering layer, a thermally conductive inorganic fiber covering layer, a thermal insulation inorganic fiber covering layer, and a thermally conductive inorganic fiber covering layer. Alternatively, the functional layer may have 6 layers, consisting of 3 layers of thermally insulating inorganic fiber covering and 3 layers of thermally conductive inorganic fiber covering from the inside out, or in the following order: thermally insulating inorganic fiber covering, thermally conductive inorganic fiber covering, thermally insulating inorganic fiber covering, thermally conductive inorganic fiber covering, thermally insulating inorganic fiber covering, thermally conductive inorganic fiber covering, thermally insulating inorganic fiber covering, and thermally conductive inorganic fiber covering.

3. The multi-layered, high-temperature resistant, and rapidly thermally conductive elastic yarn according to claim 2, characterized in that, The linear density of the heat-insulating inorganic fiber is 4 tex to 25 tex, and the heat-insulating inorganic fiber is basalt fiber or glass fiber; The thermally conductive inorganic fiber has a linear density of 5 tex to 50 tex, and the thermally conductive inorganic fiber is one of carbon fiber, graphene fiber, silicon carbide ceramic fiber, boron nitride ceramic fiber, and metal fiber. And / or, the elastic core yarn is one or more of spandex filament, silicone filament and latex filament, and the fineness of the elastic core yarn is 100D~1000D; And / or, the raw material of the flame-retardant short fiber coating layer is one or more of flame-retardant nylon, flame-retardant viscose, aramid fiber and polyimide fiber.

4. A method for preparing a multi-layered, fast-conducting, high-temperature resistant elastic yarn as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Obtain the number of functional layers and the composition of the functional layers; S2. The functional layer is wrapped onto the surface of the elastic core yarn using a braiding machine or a wrapping spinning machine to obtain a composite elastic core yarn of heat-insulating inorganic fiber and heat-conducting inorganic fiber. S3. Flame-retardant short fibers are coated onto the surface of the composite elastic core yarn of the heat-insulating inorganic fiber and the heat-conducting inorganic fiber by friction spinning to obtain a multi-layered, fast-conducting, high-temperature resistant elastic yarn.

5. The method for preparing multi-layered, fast-conducting, high-temperature resistant elastic yarn according to claim 4, characterized in that, Step S2 includes the following steps: The elastic core yarn is unwound from the first yarn tube, fed into the core yarn feed roller of the braiding machine, passes through the guide tube, passes through the guide wheel, and is fed out from the first output roller. The spindle of the braiding machine is equipped with a functional layer yarn tube. During spinning, the heat-insulating inorganic fiber filaments or heat-conducting inorganic fiber filaments of the functional layer on the spindle yarn tube are unwound and interwoven on the surface of the elastic core yarn to form a core-sheath structure. Then, it is wound onto the yarn bobbin through the output to obtain the elastic braided core yarn. By changing the type of functional layer yarn tube according to the number and composition of the functional layers in S1, and repeating the above steps, a composite elastic braided core yarn of heat-insulating inorganic fiber and heat-conducting inorganic fiber is obtained.

6. The method for preparing multi-layered, fast-conducting, high-temperature resistant elastic yarn according to claim 5, characterized in that, The speed of the core yarn feed roller of the braiding machine is 2~6m / min, the speed of the spinning spindle is 30~500r / min, the speed of the yarn output roller is 4~18m / min, and the draft ratio of the core yarn is 1~2 times.

7. The method for preparing multi-layered, fast-conducting, high-temperature resistant elastic yarn according to claim 4, characterized in that, Step S2 includes the following steps: The elastic core yarn is unwound from the second yarn tube, fed into the feeding roller of the wrapping spinning machine, and output from the second output roller through the hollow spindle. At the same time, the heat-insulating inorganic fiber filaments or heat-conducting inorganic fiber filaments in the functional layer on the hollow tube are spirally wound onto the surface of the elastic core yarn. Finally, the elastic wrapped core yarn is obtained by winding the winding mechanism. By changing the type of functional layer yarn tube according to the number and composition of the functional layers in S1, and repeating the above steps, a composite elastic wrapped core yarn of thermal insulation inorganic fiber and thermally conductive inorganic fiber is obtained.

8. The method for preparing multi-layered, fast-conducting, high-temperature resistant elastic yarn according to claim 7, characterized in that, The core yarn feeding roller speed of the wrapping spinning machine is 2.5~10m / min, the yarn output roller speed is 5~20m / min, the hollow spindle speed is 2000~8000r / min, and the core yarn draft ratio is 1~2 times.

9. The method for preparing multi-layered, fast-conducting, high-temperature resistant elastic yarn according to claim 4, characterized in that, Step S3 includes the following steps: The composite elastic braided core yarn of heat-insulating inorganic fiber and heat-conducting inorganic fiber is unwound from the third yarn tube and fed into the friction-spun core yarn feed roller. After passing through the wedge-shaped groove formed by two dust cages, the flame-retardant short fiber yarn enters the combing roller through the feed roller. The combed loose fibers are coated on the surface of the composite core yarn by the friction of the dust cage under negative pressure suction, forming a multi-level fast heat-conducting and high-temperature resistant elastic yarn. Finally, it is output through the third output roller and wound onto the fourth yarn tube.

10. The method for preparing multi-layered, fast-conducting, high-temperature resistant elastic yarn according to claim 9, characterized in that, The speed of the friction-spun core yarn feeding roller is 2~5m / min, the feeding speed of the flame-retardant short fiber sliver is 0.5~2m / min, the rotation speed of the flame-retardant short fiber combing roller is 2000~4000r / min, the rotation speed of the friction roller connected to the dust cage is 2500~5000r / min, the speed of the third output roller is 3~10m / min, and the yarn bobbin winding speed is 3.2~12m / min.

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