Basalt fiber-based fireproof intelligent sensing yarn and preparation method thereof

Abstract

This invention provides a basalt fiber-based fire-retardant smart sensing yarn and its preparation method. First, flame-retardant thermoplastic polyurethane (TPU) is non-destructively coated onto the surface of basalt filaments to obtain a high-strength, high-toughness, and wear-resistant basalt fiber composite core yarn. Then, using friction spinning technology, silver-plated flame-retardant short fibers are double-layered and coated onto the composite core yarn in the form of a layered fiber web, forming a silver-plated flame-retardant short fiber coating layer with a periodic slub structure and microporous effect on the surface, constructing a non-destructive core-spun conductive yarn. Finally, flame-retardant yarns with opposite twist directions are symmetrically wrapped around the surface of the core-spun yarn to construct a bidirectional flame-retardant coating layer. Through the above method, a skin-friendly, soft, high-strength, tough, and self-powered basalt fiber-based fire-retardant smart sensing yarn can be prepared.

Description

Technical Field

[0001] This invention relates to the field of textile technology, and in particular to a basalt fiber-based fire-resistant smart sensing yarn and its preparation method. Background Art

[0002] Fires in modern buildings are characterized by rapid spread, wide impact, and difficulty in extinguishing. A significant contributing factor is the flammability of textiles, making the development of fire-resistant and flame-retardant textiles a key research focus in the industry. Meanwhile, textiles integrating intelligent sensing functions represent the future direction for intelligent fire prevention and rescue textiles.

[0003] Ordinary fire-retardant yarns often combine flame-retardant materials directly with fibers or yarns through spraying, coating, or impregnation. This process attaches the conductive material to the surface of the yarn fibers, forming a flame-retardant layer and giving the yarn its fire-retardant properties. However, due to the limited adhesion between the flame-retardant material and the fiber, the flame-retardant material on the yarn and fabric may detach during washing or friction with the external environment, reducing its fire-retardant performance. Consequently, the durability and repeatability of flame-retardant yarns produced by these methods may not meet practical application requirements.

[0004] To address the durability issue, research into the intrinsic flame-retardant properties of fibers has become crucial. Currently used intrinsically flame-retardant fibers include polyimide, aramid, and polytetrafluoroethylene fibers; however, their operating temperature is only below 300°C, which is insufficient to withstand sustained combustion. Therefore, it is necessary to explore fibers with higher operating temperatures to improve the fire-retardant properties of yarns.

[0005] Basalt fiber is a natural mineral inorganic fiber with an extremely high oxygen index, thus exhibiting excellent flame-retardant properties. Simultaneously, it possesses good thermal insulation properties, exhibiting no melting drips or shrinkage at high temperatures (650℃), making it a potential material for developing high-performance fire-resistant and heat-insulating yarns. In existing technologies, patent publication number CN111979624A discloses a method for non-destructive coating of high-rigidity brittle fiber materials into yarns, its spinning method, and fabrics. This method uses reverse twisting techniques of ring spinning and friction spinning to form a straight, non-destructive core-shell structure composite yarn (basalt fiber). Patent publication number CN116752257A discloses a method for preparing rigid fiber non-twist shrinkage composite yarns, using reverse torque spinning of different component fibers to produce non-destructive non-twist shrinkage yarns. While the basalt fiber composite yarns obtained by these two methods possess fire-retardant properties, neither has intelligent sensing functionality. However, intelligent sensing yarns play a crucial role in fire prevention and emergency response, and have significant application value in high-rise fire prevention and fire rescue.

[0006] In view of this, it is necessary to design a basalt fiber-based fire-resistant intelligent sensing yarn and its preparation method to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide a basalt fiber-based fire-resistant intelligent sensing yarn and its preparation method, so as to obtain a skin-friendly, soft, high-strength, tough, and self-powered basalt fiber-based fire-resistant intelligent sensing yarn. This invention involves coating flame-retardant TPU onto basalt filaments to obtain a high-strength, high-toughness, and wear-resistant basalt fiber composite core yarn; then, based on friction spinning core-sleeving technology, silver-plated flame-retardant short fibers are double-layered to coat the composite core yarn in the form of a layered fiber web, forming a non-destructive core-sleeved conductive yarn with a periodic slub structure on the surface. The short fiber layer rubs against the composite core yarn to form a self-powered system; further, two flame-retardant yarns are symmetrically wrapped around the surface of the core-sleeved conductive yarn to obtain a skin-friendly, soft basalt fiber-based fire-resistant intelligent sensing yarn with good physical and mechanical properties.

[0008] To achieve the above-mentioned objectives, this invention provides a basalt fiber-based fire-resistant intelligent sensing yarn, characterized in that it comprises, from the inside out, basalt filaments, a flame-retardant TPU film, a silver-plated flame-retardant short fiber coating layer, and a flame-retardant yarn coating layer; the silver-plated flame-retardant short fiber coating layer has a periodic bamboo-like structure.

[0009] As a further improvement of the present invention, in the silver-plated flame-retardant short fiber coating layer, the spacing between adjacent bamboo joint structures is 3~5mm, and the protrusion height of the bamboo joint structure is 0.2~0.5mm.

[0010] As a further improvement of the present invention, the diameter of the basalt fiber is 0.3~0.5mm; the thickness of the flame-retardant TPU film is 0.2~1mm; the thickness of the silver-plated flame-retardant short fiber coating layer is 0.5~2mm; and the wrapping thickness of the flame-retardant yarn is 0.5~1mm.

[0011] This invention also provides a method for preparing a basalt fiber-based fire-resistant smart sensor, comprising the following steps:

[0012] S1. Flame-retardant TPU is coated onto the surface of basalt filaments to obtain composite core yarn;

[0013] S2. Using friction spinning technology, silver-plated flame-retardant short fibers are coated onto the surface of the composite core yarn to obtain a non-destructive core-spun conductive yarn;

[0014] S3. Wrap flame-retardant yarn around the surface of the non-destructive cored conductive yarn to obtain basalt fiber-based fireproof smart sensing yarn.

[0015] As a further improvement of the present invention, in step S1, the step of coating the surface of the basalt filament with flame-retardant TPU includes:

[0016] Preparation of flame-retardant TPU liquid materials;

[0017] The basalt filaments are immersed in the flame-retardant TPU liquid material, and under the stretching action, the basalt filaments are passed through small holes of a predetermined diameter to obtain basalt filaments with flame-retardant TPU coating on the surface.

[0018] The basalt filaments coated with flame-retardant TPU are subjected to heat-sealing and curing treatment to obtain the composite core yarn.

[0019] As a further improvement of the present invention, the preparation method of the flame-retardant TPU liquid material includes:

[0020] Mix TPU, flame retardant and solvent in a mass ratio of 7:2:1 and stir until homogeneous.

[0021] As a further improvement of the present invention, the temperature of the heat sealing and curing treatment is 60~120℃ and the time is 2~10min.

[0022] As a further improvement of the present invention, the diameter of the small hole is 0.7~2.5mm.

[0023] As a further improvement of the present invention, in step S2, the step of coating the surface of the composite core yarn with silver-plated flame-retardant short fibers includes:

[0024] The composite core yarn is unwound using axial unwinding technology and then fed into the twisting area of ​​a friction spinning machine;

[0025] The conductive flame-retardant short fiber slivers are divided into two partially overlapping slivers, so that the two slivers form a partially layered fiber web at the jaws formed by two dust cages rotating in the same direction, which covers the composite core yarn, so that a periodic bamboo-like structure is formed in the silver-plated flame-retardant short fiber covering layer on the surface of the composite core yarn; wherein, the width of the overlapping part of the two slivers is 1~2cm.

[0026] As a further improvement of the present invention, in step S3, the method of wrapping flame-retardant yarn on the surface of the non-destructive core-spun conductive yarn includes: using a wrapping machine to symmetrically wrap flame-retardant yarns with opposite twist directions on the surface of the non-destructive core-spun conductive yarn.

[0027] The beneficial effects of the present invention are:

[0028] 1. The method for preparing basalt fiber-based fire-resistant smart sensing yarn provided by this invention involves coating flame-retardant TPU onto basalt filaments to obtain a high-strength, high-toughness, and wear-resistant basalt fiber composite core yarn. Then, based on friction spinning core-sleeving technology, silver-plated flame-retardant short fibers are double-layered and wrapped around the composite core yarn in the form of a layered fiber web, forming a non-destructive core-sleeved conductive yarn with a periodic slub structure on its surface. The short fiber layer rubs against the composite core yarn, forming a self-powered system. Further, two flame-retardant yarns are symmetrically wrapped around the surface of the core-sleeved conductive yarn to obtain a skin-friendly, soft basalt fiber-based fire-resistant smart sensing yarn with excellent physical and mechanical properties. This basalt fiber-based fire-resistant smart sensing yarn not only possesses excellent fire-resistant and smart sensing properties but also good wearability. It can be applied not only to fire-resistant products for high-rise homes (including curtains, sofa fabrics, carpets, etc.), rescue ropes, fire tents, and other protective and rescue products, but also to clothing for firefighters, steel mill employees, and others requiring thermal protection and smart sensing functions.

[0029] 2. This invention improves the elasticity and durability of basalt fibers by coating them with flame-retardant TPU, which have high rigidity and high brittleness. Furthermore, the flame-retardant TPU film completely isolates the basalt filaments from the conductive short fibers, preventing burrs caused by friction and thus improving wearability.

[0030] 3. This invention is based on tribospun core-spun technology, in which silver-plated flame-retardant short fibers are wrapped around the core yarn in the form of a layered fiber web. In this method, the composite core yarn does not generate twist during the wrapping process, thus not causing any loss to the structure and strength of the basalt fiber. Furthermore, the surface of the formed conductive short fiber layer develops a periodic bamboo-like structure. The loosely arranged fibers in this bamboo-like structure create a microporous effect, which helps to improve the mechanical properties of the basalt fiber-based fire-retardant smart sensing yarn. Moreover, the conductive short fibers with the microporous effect generate greater friction with the flame-retardant TPU film, producing a stronger electrical signal through friction, thus achieving excellent sensing functionality.

[0031] 4. The present invention uses a wrapping machine to simultaneously wrap two flame-retardant yarns with S-twist and Z-twist respectively to symmetrically and stably wrap the core-spun yarn, effectively avoiding the bending and breakage of rigid fiber filaments (basalt fiber) during the spinning process, which would damage the structure of the rigid fiber filaments. At the same time, it tightly holds the short fibers and gives the composite yarn a soft and skin-friendly property. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the basalt fiber-based fire-resistant intelligent sensing yarn provided by the present invention.

[0033] Figure 2 This is a flowchart of the preparation method of the basalt fiber-based fire-resistant smart sensing yarn in Example 1.

[0034] Figure 3 This is a schematic diagram of coating the surface of the composite core yarn with silver-plated flame-retardant short fibers in Example 1.

[0035] Figure 4 This is a schematic diagram of the structure of the non-destructive core-spun conductive yarn obtained in Example 1.

[0036] Figure 5 This is a photograph of the basalt fiber-based fire-resistant smart sensing yarn prepared in Example 1.

[0037] Figure 6 The output voltage and output current diagrams are for the basalt fiber-based smart sensing yarn prepared in Example 1.

[0038] Figure Labels

[0039] 1. Basalt filaments; 2. Flame-retardant TPU film; 3. Silver-plated flame-retardant short fiber coating layer; 4. Flame-retardant yarn coating layer; 5. Dust cage; 6. First short fiber yarn sliver; 7. Second short fiber yarn sliver; 8. Composite core yarn; 9. Damage-free core-spun conductive yarn; 10. Slub structure. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0042] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0043] This invention provides a basalt fiber-based fire-resistant smart sensing yarn, the structural schematic of which is shown below. Figure 1 As shown, from the inside out, it includes basalt filament 1, flame-retardant TPU film 2, silver-plated flame-retardant short fiber coating layer 3 and flame-retardant yarn coating layer 4; the silver-plated flame-retardant short fiber coating layer 3 has a periodic bamboo-like structure 10.

[0044] This design not only achieves a good flame-retardant effect but also effectively protects the basalt filaments 1 using the flame-retardant TPU film 2, preventing friction between the basalt filaments 1 and the external environment. Simultaneously, the flame-retardant TPU film 2 and the silver-plated flame-retardant short fiber coating layer 3 form a self-powered system, with the flame-retardant TPU film 2 acting as the negative electrode and the silver-plated flame-retardant short fiber coating layer 3 as the positive electrode. By rubbing the basalt fiber-based fire-resistant smart sensing yarn, an electrical signal is generated between the flame-retardant TPU film 2 and the silver-plated flame-retardant short fiber coating layer, providing a sensing and early warning function. Furthermore, the loose fiber arrangement in the bamboo structure 10 creates a microporous effect, which not only improves the mechanical properties of the basalt fiber-based fire-resistant smart sensing yarn but also allows the conductive short fibers with microporous effects in the silver-plated flame-retardant short fiber coating layer 3 to generate greater friction with the flame-retardant TPU film, producing a stronger electrical signal and achieving excellent sensing functionality.

[0045] More preferably, the diameter of the basalt filaments is 0.3~0.5mm; the thickness of the flame-retardant TPU film is 0.2~1mm; the thickness of the silver-plated flame-retardant short fiber coating layer is 0.5~2mm; and the thickness of the flame-retardant yarn is 0.5~1mm. In the silver-plated flame-retardant short fiber coating layer 3, the spacing between adjacent bamboo-like structures is 3~5mm, and the protrusion height of the bamboo-like structures is 0.2~0.5mm. This configuration improves the sensing effect while giving the resulting basalt fiber-based fire-resistant intelligent sensing yarn advantages such as skin-friendly softness, high strength, and good toughness, thus meeting the needs of practical applications.

[0046] This invention also provides a method for preparing the above-mentioned basalt fiber-based fire-resistant smart sensing yarn, comprising the following steps:

[0047] S1. Flame-retardant TPU is coated on the surface of basalt filament 1 to obtain composite core yarn 8;

[0048] S2. Using friction spinning technology, silver-plated flame-retardant short fibers are coated on the surface of the composite core yarn 8 to obtain a non-destructive core-spun conductive yarn 9;

[0049] S3. Wrap flame-retardant yarn around the surface of the undamaged cored conductive yarn 9 to obtain basalt fiber-based fireproof smart sensing yarn.

[0050] Preferably, in step S1, the step of coating the surface of the basalt filament with flame-retardant TPU includes:

[0051] Preparation of flame-retardant TPU liquid materials;

[0052] The basalt filament 1 is immersed in the flame-retardant TPU liquid material, and under the stretching action, the basalt filament is made to pass through a small hole of a predetermined diameter to obtain a basalt filament with a surface coated with flame-retardant TPU.

[0053] The basalt filaments coated with flame-retardant TPU are subjected to heat-sealing and curing treatment to obtain the composite core yarn.

[0054] Using the above method, flame-retardant TPU can be uniformly coated on the surface of basalt filament 1, and excess flame-retardant TPU on the surface of basalt filament 1 can be scraped off using small holes of a predetermined diameter, thereby obtaining a composite core yarn of a predetermined diameter.

[0055] The preparation method of the flame-retardant TPU liquid material includes:

[0056] Mix TPU, flame retardant and solvent in a mass ratio of 7:2:1 and stir until homogeneous.

[0057] The flame retardant and solvent can be selected according to actual needs, as long as they can dissolve TPU and achieve a flame retardant effect. This invention is not limited to these.

[0058] The flame-retardant TPU liquid material formed by the above method not only has a flame-retardant effect, but also has a high viscosity, which can effectively adhere to the surface of the basalt filament 1 when it is immersed, and form a thick flame-retardant TPU film 2.

[0059] Preferably, the temperature of the heat-sealing curing treatment is 60~120℃ and the time is 2~10min, so that the flame-retardant TPU can be tightly wrapped around the surface of the basalt filament 1 after curing, so as to avoid friction between the basalt filament 1 and the outside world.

[0060] Preferably, the diameter of the pores is 0.7~2.5mm, so as to form a thicker flame-retardant TPU film 2, which effectively protects the basalt filaments 1 while improving their elasticity and durability.

[0061] Please refer to Figure 3-4 In step S2, the step of coating the surface of the composite core yarn with silver-plated flame-retardant short fibers includes:

[0062] The composite core yarn is unwound using axial unwinding technology and then fed into the twisting area of ​​a friction spinning machine;

[0063] The conductive flame-retardant short fiber slivers are divided into two partially overlapping slivers, so that the two slivers form a partially layered fiber web at the jaws formed by two dust cages 5 rotating in the same direction, which covers the composite core yarn, so that a periodic bamboo-like structure is formed in the silver-plated flame-retardant short fiber covering layer formed on the surface of the composite core yarn; wherein, the width of the overlapping part of the two slivers is 1~2cm.

[0064] Among them, the conductive flame-retardant short fiber is preferably a conductive flame-retardant short fiber viscose short fiber, and the fiber length is preferably 35~40mm.

[0065] It should be noted that the friction spinning machine used in this invention is an existing device, therefore its structure and specific usage method will not be described in detail here. The improvement of conventional friction spinning technology in this invention mainly lies in dividing the conductive, flame-retardant short fiber sliver into two partially overlapping strands, namely… Figure 3 The first short fiber yarn 6 and the second short fiber yarn 7 are in the middle. Based on the fact that the two partially overlapping yarns can form a partially layered fiber web, a bamboo structure can be formed in the overlapping part when the composite core yarn 8 is wrapped. The loose arrangement of fibers in the bamboo structure can form a micropore effect, which makes the signal sensing effect better and improves the mechanical properties of the basalt fiber-based fireproof smart sensing yarn.

[0066] In step S3, the method of wrapping flame-retardant yarn around the surface of the non-destructive core-spun conductive yarn includes: using a wrapping machine to symmetrically wrap flame-retardant yarn filaments with opposite twist directions around the surface of the non-destructive core-spun conductive yarn.

[0067] The above method forms a stable wrapping structure by symmetrically wrapping the flame-retardant yarn with positive and negative twists, which will not produce additional bending and twisting effects on the core yarn and avoid structural damage to the core yarn.

[0068] The flame-retardant yarn is preferably a polyimide filament, and the fineness of the polyimide filament is preferably 8~12 tex.

[0069] Specifically, polyimide filaments with opposite twist directions are respectively placed on the first and second hollow spindles of the winding machine, and the rotation directions of the first and second hollow spindles are opposite, while maintaining the same twist direction as the corresponding polyimide filaments. That is, the first hollow spindle with S-twist polyimide filaments is rotated counterclockwise, and the second hollow spindle with Z-twist polyimide filaments is rotated clockwise.

[0070] Preferably, the S-twist polyimide filament and the Z-twist polyimide filament have the same twist coefficient, ranging from 200 to 400; the first hollow spindle and the second hollow spindle rotate at the same speed, with an operating range of 4000 to 5000 r / min, to ensure that the two twisted polyimide filaments are symmetrically and tightly wrapped around the surface of the non-destructive core-spun conductive yarn 9.

[0071] The following specific embodiments further illustrate the basalt fiber fire-prevention and early warning intelligent yarn and its preparation method provided by the present invention:

[0072] Example 1

[0073] This embodiment provides a method for preparing basalt fiber-based fire-resistant smart sensing yarn, the process flow diagram of which is shown below. Figure 2 As shown, the specific steps include the following:

[0074] S1. Mix TPU, flame retardant and solvent at a mass ratio of 7:2:1 and stir evenly to obtain flame retardant TPU liquid material; immerse basalt filament 1 into the flame retardant TPU liquid material, and under stretching, make the basalt filament 1 pass through a small hole with a diameter of 1.5mm to obtain basalt filament with flame retardant TPU coating; heat-seal and cure the basalt filament with flame retardant TPU coating at 90℃ for 10 min to obtain composite core yarn 8.

[0075] S2. The composite core yarn is unwound using axial unwinding technology and then fed into the twisting area of ​​a friction spinning machine. The silver-plated flame-retardant viscose staple fiber sliver is divided into a partially overlapping first staple fiber sliver 5 and a second staple fiber sliver 6. The width of the overlapping portion between the first staple fiber sliver 5 and the second staple fiber sliver 6 is 1.5 cm. Using friction spinning technology, the two partially overlapping slivers are transported to the surface of the dust cage 5, so that the two slivers form a partially stacked fiber web at the jaws formed by the two dust cages 5 rotating in the same direction. Under the action of frictional force in the same direction, the staple fibers in the fiber web tightly wrap around the surface of the composite core yarn 8 and form a periodic slub structure 10 in the silver-plated flame-retardant staple fiber coating layer 3. The resulting composite core yarn coated with silver-plated flame-retardant staple fiber is the lossless core-spun conductive yarn 9.

[0076] S3. Place two polyimide filaments with twist directions of S twist and Z twist, and twist coefficient of 300 on the first hollow spindle and the second hollow spindle of the wrapping machine, respectively. The first hollow spindle rotates counterclockwise and the second hollow spindle rotates clockwise, both at a speed of 4500 r / min, so that the polyimide filaments are symmetrically wrapped on the surface of the non-destructive core-spun conductive yarn 9 to obtain basalt fiber-based fireproof smart sensing yarn.

[0077] The basalt fiber-based fireproof smart sensing yarn prepared in this embodiment includes, from the inside out, basalt filament 1, flame-retardant TPU film 2, silver-plated flame-retardant short fiber coating layer 3 and flame-retardant yarn coating layer 4; the silver-plated flame-retardant short fiber coating layer 3 has a periodic bamboo-like structure 10.

[0078] The basalt filaments have a diameter of 0.3 mm; the flame-retardant TPU film has a thickness of 0.6 mm; the silver-plated flame-retardant short fiber coating layer has a thickness of 1 mm; and the flame-retardant yarn has a thickness of 0.8 mm. In the silver-plated flame-retardant short fiber coating layer 3, the spacing between adjacent bamboo-like structures is 4 mm, and the protrusion height of the bamboo-like structures is 0.4 mm.

[0079] A physical image of the basalt fiber-based fire-resistant smart sensing yarn prepared in this embodiment is shown below. Figure 5 As shown.

[0080] The performance of the basalt fiber-based smart sensing yarn prepared in this embodiment was tested, and the results are shown in Table 1.

[0081] Table 1. Performance of the basalt fiber-based smart sensing yarn prepared in Example 1

[0082]

[0083] As can be seen from Table 1, the basalt fiber-based smart sensing yarn prepared in this embodiment has high tensile strength, elongation at break and good flame retardancy, which can meet the needs of practical applications.

[0084] To test the sensing performance of the basalt fiber-based smart sensing yarn prepared in this embodiment, it was subjected to regular friction, and its output voltage and output current were measured, as shown in the figure. Figure 6 As shown.

[0085] Depend on Figure 6 As can be seen, the basalt fiber-based smart sensing yarn prepared in this embodiment can stably output current and voltage, and has good sensing performance.

[0086] Comparative Example 1

[0087] This comparative example provides a basalt fiber-based fire-resistant smart sensing yarn. Compared with Example 1, the difference is that in step S2, the sliver of the silver-plated flame-retardant viscose staple fiber is only one strand, and the silver-plated flame-retardant staple fiber coating layer 3 formed does not have a bamboo joint structure. The other steps are roughly the same as in Example 1, and will not be repeated here.

[0088] The properties of the basalt fiber-based smart sensing yarn prepared in this comparative example are shown in Table 2.

[0089] Table 2. Performance of the basalt fiber-based smart sensing yarn prepared in Comparative Example 1

[0090]

[0091] Compared with Example 1, it can be seen that the tensile strength and elongation at break of the basalt fiber-based smart sensing yarn prepared in this comparative example are lower than those of Example 1, indicating that the bamboo structure in the silver-plated flame-retardant short fiber coating layer 3 can effectively improve the mechanical properties of the basalt fiber-based smart sensing yarn.

[0092] Furthermore, the sensing performance of the basalt fiber-based smart sensing yarn prepared in this comparative example is relatively weak due to the absence of a bamboo-like structure.

[0093] Comparative Example 2

[0094] This comparative example provides a basalt fiber-based fire-resistant smart sensing yarn. The difference from Example 1 is that in step S3, the polyimide filament is not symmetrically wrapped, but a twisted polyimide filament is directly wrapped around the composite core yarn. The other steps are roughly the same as in Example 1, and will not be repeated here.

[0095] The properties of the basalt fiber-based smart sensing yarn prepared in this comparative example are shown in Table 3.

[0096] Table 3. Performance of the basalt fiber-based smart sensing yarn prepared in Comparative Example 2

[0097]

[0098] Compared with Example 1, it can be seen that the tensile strength and elongation at break of the basalt fiber-based smart sensing yarn prepared in this comparative example are lower than those of Example 1, indicating that symmetrical wrapping of polyimide filaments is beneficial to improving the tensile strength and elongation at break of the basalt fiber-based smart sensing yarn.

[0099] In summary, this invention provides a basalt fiber-based fire-resistant intelligent sensing yarn and its preparation method. First, flame-retardant thermoplastic polyurethane (TPU) is non-destructively coated onto the surface of basalt filaments to obtain a high-strength, high-toughness, and wear-resistant basalt fiber composite core yarn. Then, using friction spinning technology, silver-plated flame-retardant short fibers are double-layered and coated onto the composite core yarn in the form of a layered fiber web, forming a silver-plated flame-retardant short fiber coating layer with a periodic bamboo-like structure and microporous effect, constructing a non-destructive core-spun conductive yarn. Next, flame-retardant yarns with opposite twist directions are symmetrically wrapped around the surface of the core-spun yarn to construct a bidirectional flame-retardant layer. Through this method, a skin-friendly, soft, high-strength, tough, and self-powered basalt fiber-based fire-resistant intelligent sensing yarn can be prepared, making it suitable not only for high-rise residential fire protection products (including curtains, sofa fabrics, carpets, etc.), rescue ropes, fire tents, and other protective and rescue products, but also for clothing requiring thermal protection and intelligent sensing functions, such as those worn by firefighters and steel mill employees.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a basalt fiber-based fire-resistant smart sensing yarn, characterized in that, Includes the following steps: S1. Flame-retardant TPU is coated onto the surface of basalt filaments to obtain composite core yarn; S2. Using friction spinning technology, silver-plated flame-retardant short fibers are coated onto the surface of the composite core yarn to obtain a non-destructive core-spun conductive yarn; S3. Wrap flame-retardant yarn around the surface of the non-destructive core-spun conductive yarn to obtain basalt fiber-based fireproof smart sensing yarn; The step of coating the surface of the basalt filaments with flame-retardant TPU includes: Preparation of flame-retardant TPU liquid materials; The basalt filaments are immersed in the flame-retardant TPU liquid material, and under the stretching action, the basalt filaments are passed through small holes of a predetermined diameter to obtain basalt filaments with flame-retardant TPU coating on the surface. The basalt filaments coated with flame-retardant TPU are subjected to heat-sealing and curing treatment to obtain the composite core yarn; The step of coating the surface of the composite core yarn with silver-plated flame-retardant short fibers includes: The composite core yarn is unwound using axial unwinding technology and then fed into the twisting area of ​​a friction spinning machine; The conductive flame-retardant short fiber slivers are divided into two partially overlapping slivers, so that the two slivers form a partially layered fiber web at the jaws formed by two dust cages rotating in the same direction, which covers the composite core yarn, so that a periodic bamboo-like structure is formed in the silver-plated flame-retardant short fiber covering layer on the surface of the composite core yarn; wherein, the width of the overlapping part of the two slivers is 1~2cm.

2. The method for preparing basalt fiber-based fire-resistant intelligent sensing yarn according to claim 1, characterized in that, The preparation method of the flame-retardant TPU liquid material includes: Mix TPU, flame retardant and solvent in a mass ratio of 7:2:1 and stir until homogeneous.

3. The method for preparing basalt fiber-based fire-resistant intelligent sensing yarn according to claim 1, characterized in that, The temperature for the heat sealing and curing treatment is 60~120℃, and the time is 2~10min.

4. The method for preparing basalt fiber-based fire-resistant intelligent sensing yarn according to claim 1, characterized in that, The diameter of the small hole is 0.7~2.5mm.

5. The method for preparing basalt fiber-based fire-resistant intelligent sensing yarn according to claim 1, characterized in that, In step S3, the method of wrapping flame-retardant yarn around the surface of the non-destructive core-spun conductive yarn includes: using a wrapping machine to symmetrically wrap flame-retardant yarns with opposite twist directions around the surface of the non-destructive core-spun conductive yarn.

6. A basalt fiber-based fire-resistant intelligent sensing yarn, characterized in that, The basalt fiber-based fire-retardant smart sensing yarn is prepared by any one of claims 1 to 5. The basalt fiber-based fire-retardant smart sensing yarn comprises, from the inside out, basalt filaments, a flame-retardant TPU film, a silver-plated flame-retardant short fiber coating layer, and a flame-retardant yarn coating layer. The silver-plated flame-retardant short fiber coating layer has a periodic bamboo-like structure.

7. The basalt fiber-based fire-resistant intelligent sensing yarn according to claim 6, characterized in that, In the silver-plated flame-retardant short fiber coating layer, the spacing between adjacent bamboo-like structures is 3-5 mm, and the protrusion height of the bamboo-like structures is 0.2-0.5 mm.

8. The basalt fiber-based fire-resistant intelligent sensing yarn according to claim 6, characterized in that, The diameter of the basalt filament is 0.3~0.5mm; the thickness of the flame-retardant TPU film is 0.2~1mm; the thickness of the silver-plated flame-retardant short fiber coating layer is 0.5~2mm; and the wrapping thickness of the flame-retardant yarn is 0.5~1mm.

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