A kind of blended conductive yarn and preparation method thereof

Abstract

The present invention relates to a blended conductive yarn and a preparation method thereof. When preparing, conductive fibers and insulating clothing fibers are used as raw materials, and a blended conductive yarn is prepared by a double-feed and double-combing rotor spinning process; in the raw materials, the content of the conductive fibers is 5-10 wt%; the conductivity-softness-strength index W of the blended conductive yarn is 1.7-19.85 (cm2) / (10·Ω·g); the conductive fibers in the blended conductive yarn aggregate in the yarn and are distributed in a three-dimensional spiral shape along the axial direction of the yarn, constructing a continuous conductive path, and the insulating clothing fibers closely surround and wrap the conductive fibers. The preparation method of the present invention realizes the control of the conductive performance of the yarn by precisely adjusting the mixing ratio of the conductive fibers and the insulating clothing fibers and the fineness of the yarn; the blended conductive yarn can achieve high conductive performance under the condition of low initial modulus and at the same time take into account the breaking strength.

Description

Technical Field

[0001] The present invention belongs to the field of new textile technologies and relates to a blended conductive yarn and a preparation method thereof. Background Art

[0002] With the rapid development of smart wearable devices and e-textiles, the demand for conductive yarns is increasing day by day. Conductive yarns can not only provide anti-static and electromagnetic shielding functions, but also be used as sensors and conductive connections in smart textiles. However, the conductive yarns prepared by the existing technologies have problems such as unsatisfactory conductive performance and spinnability, a relatively stiff handfeel, and poor stability.

[0003] First of all, in the existing technologies, conductive filaments are not suitable for direct use in the weaving process due to their physical properties. Generally, specific spinning processes are adopted for the preparation of conductive yarns, where the conductive filaments are used as core yarns or are wrapped by insulating fibers outside the yarn, and such a structure is used to manufacture yarns that have both conductive performance and are suitable for weaving. For example, Patent CN 214882054U discloses an anti-static yarn, where the core yarn is twisted from several strands of chemical fiber filaments, and several strands of twisted conductive filaments are then helically wound around the core yarn, and the outermost layer is a covering yarn for protection. This type of yarn has a certain anti-static function. However, in the actual application process, since the breaking elongation rate of the conductive filaments is usually lower than that of other components in the yarn, when subjected to tensile, bending or other mechanical stress, the conductive filaments are prone to separation or delamination from other structures of the yarn, affecting the conductivity and structural stability of the yarn.

[0004] Secondly, the existing conductive yarns have the following deficiencies in the comprehensive performance of conductivity, softness and breaking strength:

[0005] (1) Document 1 (Electrical and Mechanical Properties of Poly(Trimethylene Terephthalate) / Polyaniline Composite Conductive Yarns [J]. Journal of Textile Research, 2017, 38(02): 40-46.) reported a preparation method of a composite conductive yarn. This method uses 17 tex poly(trimethylene terephthalate) filaments as the base material, and through aniline in-situ polymerization technology, a conductive yarn with an initial modulus of 25.74 cN / dtex is obtained. This is the lowest initial modulus that conductive yarns can reach in the currently publicly reported cases. The breaking strength of this yarn is 33.29 cN / tex, and the mass specific resistance is 25.16 Ω·g / cm 2 , and after calculation, W = 0.05. It is difficult to achieve high conductive performance at a low initial modulus while also taking into account the breaking strength. This conductive yarn shows excellent performance in terms of softness. However, it has a relatively large mass specific resistance, poor conductive performance, and the conductive molecules of this conductive yarn are attached to the surface of the yarn, lacking insulation effect and being prone to abrasion, and it needs to be further compounded with insulating fibers to have practical value.

[0006] (2) Document 2 (Application of Graphene in Improving the Conductivity of Polyaniline / Aramid Composite Yarns [J]. Dyeing & Finishing, 2022, 48(02): 45-48+72.) reported a preparation method of a composite conductive yarn. This method uses 104 tex aramid filament yarn as the base material and graphene as the conductive reinforcing filler material to prepare a graphene@polyaniline / aramid composite conductive yarn with a breaking strength of 160.5 cN / tex. This is the highest breaking strength that conductive yarns can reach in currently publicly reported literature. The mass specific resistance of this yarn is 0.58 Ω·g / cm 2 , with an initial modulus of 664.9 cN / dtex, and the calculated conductivity-softness-strength index W = 0.42. The strength performance of this conductive yarn is excellent, but the initial modulus of the yarn is relatively high, resulting in excessive stiffness of the yarn, a hard and unyielding feel, and it is not suitable for weaving into fabric.

[0007] (3) Document 3 (Research on the Electromagnetic Radiation Protection Performance of Stainless Steel Fiber Blended Fabrics [D]. Zhejiang Sci-Tech University, 2019.) prepared a 60.8 tex polyester / stainless steel staple fiber blended yarn through ring spinning technology using polyester and stainless steel staple fibers as raw materials, with the mass content of conductive stainless steel fibers being 27%. The mass specific resistance of this conductive yarn is 0.08 Ω·g / cm2, which is the minimum mass specific resistance that blended conductive yarns can reach in currently publicly reported literature. The breaking strength of this yarn is 21.30 cN / dtex, and the initial modulus is 163.60 cN / dtex. The calculated conductivity-softness-strength index W = 1.55. The poor elasticity of stainless steel fibers results in a relatively high initial modulus of the yarn, and the high content of stainless steel fibers in this yarn increases the production cost; at the same time, the internal and external transfer of fibers is a typical characteristic of ring-spun yarns, and the internal and external transfer of stainless steel fibers will lead to uneven distribution of conductive fibers in the yarn, thus causing fluctuations in conductive performance. During the stretching or deformation process, the resistance change of the yarn is relatively large, which is difficult to meet the application requirements of high-precision sensors.

[0008] In summary, the existing conductive yarns have many deficiencies in terms of structural stability, high conductivity, softness, and strength, which limit their application in smart textiles and electronic devices.

[0009] Therefore, it is of great significance to study a blended conductive yarn with both high conductivity, softness, and breaking strength and its preparation method to solve the problems existing in the prior art. Summary of the Invention

[0010] The object of the present invention is to solve the problems existing in the prior art and provide a blended conductive yarn and its preparation method.

[0011] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0012] A preparation method of a blended conductive yarn uses conductive fibers and insulating clothing fibers as raw materials and prepares the blended conductive yarn by a double-feed and double-combing rotor spinning process;

[0013] In the raw materials, both the conductive fibers and the insulating clothing fibers are short fibers, and the content of the conductive fibers is 5-10 wt%. When the content of the conductive fibers is less than 5 wt%, due to the insufficient number of conductive fibers, a continuous arrangement cannot be formed in the yarn, resulting in the breakage of the conductive path in the yarn, thereby affecting the formation of a stable conductive network. When the content of the conductive fibers exceeds 10 wt%, with the increase in the content of the conductive fibers, some conductive fibers will migrate to the surface of the yarn. Moreover, some conductive fibers will become wrapping fibers and wrap around the outer layer of the yarn. This exposure of the conductive fibers will weaken the surface insulation of the blended conductive yarn, and at the same time, the uneven distribution of the conductive fibers will also affect the stability of the conductive effect;

[0014] The conductivity-softness-strength index W of the blended conductive yarn is 1.7-19.85, and the conductivity-softness-strength index W is defined as:

[0015]

[0016] In the formula, the unit of W is (cm 2 ) / (10·Ω·g); S is the breaking strength, indicating the maximum tensile force that each tex of yarn can withstand. The larger S is, the higher the strength of the yarn. The unit is cN / tex; E is the initial modulus, indicating the ease of deformation of the yarn under a small load and reflecting the rigidity of the yarn. The smaller E is, the softer the yarn. The unit is cN / dtex; ρ m is the mass specific resistance, indicating the ratio of the voltage per unit length of the conductive yarn to the current flowing through the yarn per unit linear density. The smaller ρ m is, the better the conductive performance of the yarn and the more uniform the distribution of the conductive fibers in the yarn. The unit is Ω·g / cm 2 ;

[0017] The blended conductive yarn of the present invention has both high conductivity, softness and breaking strength, and a conductivity-softness-strength index W is defined to characterize and evaluate the comprehensive performance of the conductive yarn. The larger W is, the lower the initial modulus (i.e., softer) and the higher the breaking strength of the blended conductive yarn while maintaining high conductive performance, thereby indicating that its comprehensive performance is more excellent.

[0018] As a preferred technical solution:

[0019] A preparation method of the blended conductive yarn as described above, wherein the length of the conductive fiber is 18 - 58 mm and the fineness is 1.3 - 4 dtex. If the length of the conductive fiber is less than 18 mm, the cohesion between conductive fibers is weakened, thereby reducing the breaking strength of the yarn. If the length of the conductive fiber is greater than 58 mm, the risk of fiber entanglement increases. If the fineness of the conductive fiber is less than 1.3 dtex, the strength of the conductive fiber is too low and it is easily cut by the teeth of the corresponding carding roller. If the fiber fineness is greater than 4 dtex, the coarse fiber is not easily carded by the carding roller and it is likely to cause the yarn to feel stiff and increase the yarn defects. The length of the insulating clothing fiber is 18 - 70 mm and the fineness is 1.3 - 4 dtex. If the length of the fiber is less than 18 mm, the entanglement force between fibers becomes smaller, resulting in a smaller breaking strength of the yarn. If the length of the fiber is greater than 70 mm, because the length of the insulating clothing fiber is too long, it is not easily all twisted into the yarn body during the twisting process, and the part remaining outside the yarn is likely to become the hairiness of the yarn. Moreover, the difference in length from the conductive fiber is too large, and the insulating clothing fiber is likely to form wrapped fibers on the surface of the yarn, which will affect the final conductive effect of the yarn. The reason for the selection of the fineness value range of the insulating clothing fiber is the same as that of the conductive fiber.

[0020] A preparation method of the blended conductive yarn as described above, wherein the conductive fiber is a composite conductive fiber, which is formed by attaching conductive particles or conductive materials to insulating fibers by means of filling or coating, including but not limited to carbon black / polymer composite conductive fibers, metal / polymer composite conductive fibers, graphite / polymer composite conductive fibers, conductive polymer composite conductive fibers, and mixed filler composite conductive fibers; the insulating clothing fiber is one or more of natural fibers and chemical fibers, specifically including but not limited to cotton fibers, polyester fibers, and viscose fibers.

[0021] A preparation method of the blended conductive yarn as described above, and the specific preparation process is as follows: the conductive fiber and the insulating clothing fiber are respectively formed into uniform conductive fiber sliver and insulating clothing fiber sliver after carding and drawing processes. After the conductive fiber sliver and the insulating clothing fiber sliver are respectively drawn out from their respective cans, they are respectively held by their respective feed rollers and feed plates, and the mixing ratio of the two fibers is adjusted by adjusting the rotation speeds of the two feed rollers; after the two fiber slivers are actively transported forward by their respective feed rollers, they are respectively carded by two independent carding rollers to form two fiber streams. After the two fiber streams are transported through their respective fiber conveying channels, they respectively enter the condensation groove of the rotor from the fiber outlet of the two fiber conveying channels to form a condensed sliver. The condensed sliver is twisted by the high-speed rotation of the rotor and then led out by the yarn drawing roller and wound into a blended conductive yarn.

[0022] A preparation method of the blended conductive yarn as described above, denote the feeding speed of the feed roller X corresponding to the conductive fiber as ux The feeding speed of the feeding roller Y corresponding to the insulating clothing fiber is u y The linear density of the yarn is T, the drawing speed is V, the mass content of the conductive fiber in the raw material is denoted as x%, and the mass content of the insulating clothing fiber in the raw material is denoted as y%; the quantitative of the conductive fiber sliver corresponding to the conductive fiber is Q x The quantitative of the insulating clothing fiber sliver corresponding to the insulating clothing fiber is Q y ; where, u x and u y The unit of is m·min -1 The unit of T is tex, and the unit of V is m·min -1 , Q x and Q y The unit of is g·(5m) -1 ;

[0023] The above parameters satisfy the following formula:

[0024] x + y = 100;

[0025] 5 ≤ x ≤ 10;

[0026]

[0027] 200(Q x u x + Q y u y ) = VT.

[0028] For a preparation method of a blended conductive yarn as described above, the value range of T is 14 - 70 tex, Q x and Q y The value range of is 3 - 30 g·(5m) -1 The value range of V is 40 - 120 m·min -1 , u x The value range of is u x > 0, u y The value range of is u y > 0.

[0029] For a preparation method of a blended conductive yarn as described above, the rotational speed of the carding roller X corresponding to the conductive fiber is 4000 - 6000 r·min -1 , if the rotational speed of the carding roller corresponding to the conductive fiber is too fast, it will increase the friction between the conductive fiber and the carding roller teeth, resulting in damage to the conductive fiber and thus affecting its conductive effect; the rotational speed of the carding roller Y corresponding to the insulating clothing fiber is 4000 - 9000 r·min -1 ; the rotational speed of the rotor is 25000 - 150000 r·min-1 。

[0030] A method for preparing a blended conductive yarn as described above, wherein the working angle of the carding roller X is 6° - 9°, the tooth depth is 2.1 - 2.4 mm, and the tooth density is 12 - 16 teeth / (25.4 mm) 2 ;

[0031] The working angle, tooth depth, and tooth density are all professional terms; the working angle refers to the angle between the teeth on the carding roller and the horizontal plane. Within this range of the working angle α, the ability of the needle teeth to penetrate the fiber layer becomes stronger, it is easier to grasp the fibers, the carding quality is improved, and the damage to the conductive particles or conductive materials of the conductive fibers is reduced; the tooth depth refers to the depth of each tooth on the carding roller. Within this range of the tooth depth, the efficiency of fiber transfer from the needle teeth can be improved; the tooth density refers to the number of teeth per unit area. Within this range of the tooth density, although the carding efficiency is reduced, the contact probability between the conductive fibers and the needle teeth becomes smaller, which is beneficial to reducing fiber damage.

[0032] Rotor spinning is an efficient short - fiber spinning technology suitable for large - scale production. The carding roller is one of the key components of rotor spinning. By carding the fiber sliver, it decomposes it into single fibers, facilitating the cohesion of the fibers in the rotor. Literature 4 ("Key Equipment and Process Optimization of Rotor - Spun Polyester - Cotton Blended Yarn" [J]. Textile Accessories, 2024, 51(04): 11 - 16.) analyzed the influence of the main process parameters of the carding roller teeth on the properties of rotor yarn. Currently, the tooth depth of the traditional carding roller teeth is generally 2.5 mm, the working angle is small (10° - 40°) and the tooth density is high (greater than 18.56 teeth / (25.4 mm) 2 ), the ability of the needle teeth to penetrate the fiber layer is relatively strong, suitable for processing conventional fibers, but it is easy to cause damage to the conductive fibers with conductive particles attached. Patent CN113604923A discloses a composite conductive core - spun yarn and its preparation method. This technology combs the graphene / silver / cotton composite conductive fibers into a fiber stream through a carding roller, and then sends it into the rotor through a fiber - conveying channel, and spins it into a conductive core - spun yarn together with the introduced filament in a rotor spinning machine. However, during the carding process, the conductive particles on the conductive fibers are prone to friction with the sharp teeth of the closely arranged carding roller, causing fiber damage and affecting the conductive performance of the yarn. And, patent CN103911695A discloses a double - feeding and double - carding rotor spinning device, which is equipped with an additional set of "feeding roller - carding roller - fiber - conveying channel" mechanism on the basis of a traditional rotor spinning machine, and can realize the independent feeding, carding, and conveying of two kinds of short fibers. This spinning device is suitable for spinning rotor - spun blended yarns. Therefore, how to use rotor spinning technology to prepare conductive yarns with high conductivity, softness, and high strength remains a technical challenge. The present invention adopts a double - feeding and double - carding rotor spinning process, and designs the main process parameters of the teeth of the carding roller X corresponding to the conductive fibers, and successfully prepares a blended conductive yarn with both high conductivity, softness, and breaking strength.

[0033] The present invention also provides a blended conductive yarn prepared by any of the preparation methods described above, wherein the conductive fibers in the blended conductive yarn are gathered in the yarn and distributed in a three-dimensional spiral along the axial direction of the yarn, forming a continuous conductive path, thereby giving the yarn excellent conductive properties. At the same time, the insulating clothing fibers tightly surround and wrap the conductive fibers, which not only provides the necessary physical and mechanical support for the yarn, but also enhances the softness of the yarn, while effectively protecting the conductive fibers from external damage.

[0034] The insulating clothing fibers with a higher content tightly surround and wrap the conductive fibers, which not only provide the necessary physical and mechanical support for the yarn, but also increase the softness of the yarn and effectively protect the conductive fibers from damage. Compared with core-spun or wrapped conductive yarns, the conductive material is more likely to separate or delaminate from other structures in the yarn, resulting in unstable conductive performance and shortened service life. The conductive fibers and the insulating clothing fibers in the blended conductive yarn involved in the present invention are both short fibers, which are tightly entangled on the fiber scale. The cohesive force between the fibers significantly enhances the stability of the conductive fibers, making it difficult for them to separate from the yarn structure. Therefore, this blended conductive yarn can achieve high conductivity at a low initial modulus while taking into account breaking strength, providing a more durable and stable conductive solution for the application of clothing fabrics and smart textiles.

[0035] The structure of the blended conductive yarn produced by ring spinning technology is compact. Both the conductive fiber and the insulating clothing fiber are mostly transferred in and out in the form of conical spirals, so that the fibers are entangled and connected with each other in the yarn. However, this fiber transfer in and out may lead to uneven distribution of the conductive fiber in the yarn, especially when the conductive fiber content is low. This unevenness may cause fluctuations in the conductive properties of the yarn. During the stretching or deformation process, the resistance of the yarn changes greatly, which makes it difficult to meet the application requirements of high-precision sensors.

[0036] The unique structure of the blended conductive yarn involved in the present invention is attributed to the fact that during the high-speed rotation of the rotor, the conductive fibers and insulating clothing fibers fed into the spinneret at different feeding speeds have different landing points in the rotor, resulting in differences in the arrangement of the fibers in the sliver in the condensing groove. Furthermore, the distribution of the two types of fibers in the final yarn presents a unique structure. Among them, the conductive fibers with a lower content are continuously distributed along the axial direction of the yarn in a spiral pattern, constructing a stable conductive network; while the insulating clothing fibers with a higher content tightly wrap these conductive fibers, providing the necessary physical properties and flexibility for the yarn. This structural design enables the conductive yarn to not only have excellent conductive properties but also good mechanical strength and softness, making it very suitable for application in flexible intelligent wearable fabrics, meeting the dual requirements of modern intelligent textiles for conductive properties and comfort.

[0037] Beneficial effects:

[0038] (1) For the preparation method of a blended conductive yarn of the present invention, the raw materials for preparation include conductive fibers and insulating clothing fibers, and it is spun by a double-feeding and double-combing rotor spinning process; after the conductive fibers are combed by the modified combing roller, the fiber damage rate is reduced; the low-content conductive fibers form aggregates inside the yarn and unfold in a three-dimensional spiral shape along the axial direction of the yarn, forming a continuous conductive path to ensure the conductive properties of the yarn; while the high-content insulating clothing fibers tightly wrap the conductive fibers, providing the necessary mechanical support, enhancing the softness of the yarn, and physically protecting the conductive fibers from potential damage.

[0039] (2) For the preparation method of a blended conductive yarn of the present invention, by optimizing the rack structure parameters of the combing roller X to adapt to the characteristics of the conductive fibers, the damage rate of the conductive fibers during the combing process is reduced; by precisely adjusting the mixing ratio of the conductive fibers and the insulating clothing fibers and the fineness of the yarn, the control of the conductive properties of the yarn is achieved to meet diverse application requirements; this regulation mechanism provides greater flexibility for the design of conductive yarns, enabling them to meet the needs of specific application scenarios.

[0040] (3) The blended conductive yarn prepared by the method of the present invention can achieve high conductive performance at a low initial modulus while taking into account the breaking strength, and it performs excellently in terms of conductive properties, serviceability, and structural stability, providing a durable and stable conductive function solution for the fields of clothing fabrics and intelligent wearable textiles, meeting the requirements of modern technology for conductive materials. Description of the Drawings

[0041] Figure 1 is a schematic diagram of the blended conductive yarn of the present invention;

[0042] Figure 2It is a schematic diagram of the working state of the rotor spinning machine of the present invention;

[0043] Figure 3 It is a schematic diagram of the carding roller rack; wherein, α is the working angle, that is, the angle between the rack on the carding roller and the horizontal plane; l is the tooth depth, referring to the depth of each tooth on the carding roller;

[0044] Figure 4 It is a specific distribution pattern diagram of the silver-plated polyamide conductive fiber in the yarn in Example 1; An OK_AC5067 industrial camera produced by Beijing Jiaheng Zhongzi Image Technology Co., Ltd. was used to photograph the specific distribution pattern of the silver-plated polyamide conductive fiber in the yarn in Example 1;

[0045] Among them, 1 - conductive fiber sliver, 2 - insulating clothing fiber sliver, 3 - feed roller X, 4 - feed roller Y, 5 - carding roller X, 6 - carding roller Y, 7 - fiber transmission channel X, 8 - fiber transmission channel Y, 9 - rotor, 10 - yarn drawing roller, 11 - blended conductive yarn, 12 - conductive fiber, 13 - insulating clothing fiber. Specific Embodiments

[0046] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0047] The specific sources of the materials used in the embodiments and comparative examples of the present invention are as follows:

[0048] Silver-plated polyamide conductive fiber: The manufacturer is Qingdao Hengtong Weiye Special Fabric Technology Co., Ltd.;

[0049] Polyester fiber: The manufacturer is Zhejiang Hengyi Group Co., Ltd.;

[0050] Composite carbon black conductive fiber: The manufacturer is Kaitai Special Fiber Technology Co., Ltd.;

[0051] Cotton fiber: The manufacturer is China Color Cotton (Group) Co., Ltd.;

[0052] Composite polyaniline conductive fiber: The manufacturer is Foshan Ruinengda Special Materials Technology Co., Ltd.;

[0053] Viscose fiber: The manufacturer is Xinjiang Zhongtai Chemical Co., Ltd.;

[0054] Composite graphene conductive fiber: The manufacturer is Hangzhou Gaoxi Technology Co., Ltd.;

[0055] Recycled cotton fiber: The manufacturer is China Color Cotton (Group) Co., Ltd.

[0056] The test methods for the performance indicators in the embodiments and comparative examples of the present invention are as follows:

[0057] Mass specific resistance: Refer to the standard DB41 / T 1790-2019 to test the mass specific resistance ρ of the yarn m , and the specific meaning of the mass specific resistance is the ratio of the voltage of the conductive yarn per unit length to the current flowing through the yarn per unit linear density, with the unit of Ω·g / cm 2 , ρ m Taking into account the length and linear density of the conductive yarn, this index can evaluate the conductive performance of conductive yarns with different finenesses and the uniformity of the distribution of conductive fibers in the yarn.

[0058] Breaking strength S and initial modulus E: Refer to the standard GBT 3916-2013 to test the breaking strength S and initial modulus E of the yarn. The units of the breaking strength S and initial modulus E are cN / tex and cN / dtex respectively.

[0059] In the embodiment, the distribution pattern of the conductive fibers in the conductive yarn is characterized by the tracer fiber technology. The basic principle of the tracer fiber method is to place the blended conductive yarn in a solution with an optical refractive index equal to the average refractive index of the insulating clothing fibers. The insulating clothing fibers in the yarn are basically in a transparent state. This solution is prepared by mixing turpentine and α-bromonaphthalene (with a volume ratio of 1:1). Finally, the conductive yarn immersed in the solution is observed under a microscope, and the distribution pattern of the conductive fibers in the yarn can be observed.

[0060] Example 1

[0061] A preparation method of a blended conductive yarn, the specific steps are as follows:

[0062] (1) Preparation of raw materials:

[0063] Conductive fiber: Silver-plated polyamide conductive fiber, which is formed by attaching silver-plated particles (with a particle size of 223nm) to the polyamide fiber by a coating method; the length of the conductive fiber is 38mm, and the fineness is 1.67dtex;

[0064] Insulating clothing fiber: Polyester fiber; the length is 38mm, and the fineness is 1.38dtex;

[0065] (2) As Figure 2As shown in the figure, after the conductive fiber 12 and the insulating clothing fiber 13 are respectively carded and drawn into slivers, a uniform conductive fiber sliver 1 and an insulating clothing fiber sliver 2 are formed. After the conductive fiber sliver 1 and the insulating clothing fiber sliver 2 are respectively drawn out from their respective cans, they are respectively held by the feed roller X 3 and the feed roller Y 4 and the feed plate; after the two fiber slivers are actively fed forward by their respective feed rollers, they are respectively combed by the independent carding roller X 5 and the carding roller Y 6 to form two fiber streams. After the two fiber streams are transported through their respective corresponding fiber conveying channels X 7 and fiber conveying channels Y 8, they respectively enter the condensing groove of the rotor 9 from the fiber outlet of the two fiber conveying channels to form a condensed beard. The condensed beard is twisted by the high-speed rotation of the rotor 9 and then drawn out by the yarn drawing roller 10 and wound into a blended conductive yarn 11;

[0066] Let the feeding speed of the feed roller X 3 corresponding to the conductive fiber 12 be u x , and the feeding speed of the feed roller Y 4 corresponding to the insulating clothing fiber 13 be u y , the linear density of the yarn is T, T = 40 tex, and the yarn drawing speed is V, V = 75 m·min -1 ; the mass content of the conductive fiber 12 in the raw material is recorded as x%, x = 5, and the mass content of the insulating clothing fiber in the raw material is recorded as y%, y = 95; the quantitative value of the conductive fiber sliver corresponding to the conductive fiber is Q x , Q x = 3.35 g·(5 m) -1 , and the quantitative value of the insulating clothing fiber sliver 2 corresponding to the insulating clothing fiber 13 is Q y , Q y = 18.86 g·(5 m) -1 ; According to x, y, Q x , Q y , T, V, the calculated u x = 0.224 m·min -1 , u y = 0.756 m·min -1 ;

[0067] The rotating shafts of the feed roller X and the feed roller Y rotate at speeds of u x and u y respectively, so as to realize feeding the conductive fiber and the insulating clothing fiber into the rotor spinning machine at the set mixing ratio at the same time; the rotational speed of the carding roller X corresponding to the conductive fiber is 4500 r·min -1 , and the rotational speed of the carding roller Y corresponding to the insulating clothing fiber is 7500 r·min -1 ; the rotational speed of the rotor is 60000 r·min -1 ; As Figure 3As shown, the working angle of the carding roller X is 8°, the tooth depth is 2.3 mm, and the tooth density is 16 teeth / (25.4 mm). 2 ; The working angle of the carding roller Y is 15°, the tooth depth is 2.7 mm, and the tooth density is 61 teeth / (25.4 mm). 2 .

[0068] As Figure 1 shown, the conductive fibers in the finally prepared blended conductive yarn aggregate in the yarn and are distributed in a three-dimensional spiral shape along the axial direction of the yarn, constructing a continuous conductive path, and the insulating clothing fibers closely surround and wrap the conductive fibers; the breaking strength S of the blended conductive yarn is 13.27 cN / tex, the initial modulus E is 35.56 cN / dtex, and the mass specific resistance ρ m = 0.22 Ω·g / cm 2 . The conductivity-softness-strength index W calculated from S, E, and ρ m is 1.7.

[0069] When the prepared blended conductive yarn is immersed in a tracer solution with an optical refractive index equal to the average refractive index of polyester fibers (1.575), the specific distribution pattern of the silver-plated polyamide conductive fibers in the yarn can be observed as Figure 4 shown. The conductive fibers exhibit a continuous and three-dimensional spiral arrangement along the axis of the yarn, constructing a unique aggregation structure; the conductive fibers are basically continuously and uniformly distributed inside the yarn, ensuring that the yarn can exhibit consistent and continuous conductive performance in all length ranges, and indicating that the yarn can maintain a stable conductive effect throughout its length.

[0070] Comparative Example 1

[0071] A method for spinning a blended conductive yarn is basically the same as that in Example 1, except that: for the carding roller X for conductive fibers, its specifications are the same as those of the carding roller Y for processing insulating clothing fibers, specifically, the working angle α = 15°, the tooth depth l = 2.7 mm, and the tooth density = 61 teeth / (25.4 mm). 2 .

[0072] The mass specific resistance of the finally prepared blended conductive yarn is 12.75 Ω·g / cm 2 ; The breaking strength is 8.79 cN / tex; the initial modulus is 34.19 cN / dtex; W = 0.02.

[0073] Comparing Comparative Example 1 with Example 1, it can be found that the mass specific resistance of the blended conductive yarn in Comparative Example 1 increases, and the breaking strength and initial modulus decrease, indicating that the conductive fibers are damaged to varying degrees during the carding process, which affects the conductive performance, softness, and strength of the yarn to varying degrees.

[0074] Comparative Example 2

[0075] A spinning method for blended conductive yarn is basically the same as that of Example 1, except that the ring spinning method is used to spin the blended conductive yarn. The fiber strips formed after the roving drafting of the two fiber raw materials are introduced by the rotation of the ring traveler, and the winding speed of the bobbin exceeds that of the traveler, so that the two rovings are twisted to form the blended conductive yarn;

[0076] The specific process parameters are as follows: the spindle speed is 4000 rpm, the back zone draft multiple is 1.10; the roller gauge is 45*55 mm; the upper and lower apron nip gauge is 5.5 mm.

[0077] The test result of the mass specific resistance of the finally prepared product is 19.45 Ω·g / cm 2 ; the breaking strength is 14.07 cN / tex; the initial modulus is 38.23 cN / dtex; W = 0.02.

[0078] Comparing Comparative Example 1 and Example 1, it can be found that when the spinning method is changed to ring spinning, the mass specific resistance, breaking strength and initial modulus of the blended conductive yarn in Comparative Example 2 all increase. Among them, the increase in mass specific resistance is obvious, indicating that the conductivity of the yarn becomes worse, and the parameter W becomes smaller, indicating that the comprehensive performance of the blended conductive yarn becomes worse.

[0079] Example 2

[0080] A preparation method for blended conductive yarn is basically the same as that of Example 1, except that the linear density T of the yarn is 42.5 tex, and the corresponding calculated u x = 0.238 m·min -1 u y = 0.803 m·min -1 .

[0081] The mass specific resistance ρ of the finally prepared blended conductive yarn m is 0.19 Ω·g / cm 2 , the breaking strength S is 13.52 cN / tex; the initial modulus E is 38.09 cN / dtex; the conductivity-softness-strength index W calculated from S, E and ρ m is 1.87.

[0082] Example 3

[0083] A preparation method for blended conductive yarn is as follows:

[0084] (1) Preparation of raw materials:

[0085] Conductive fiber: The composite carbon black conductive fiber is formed by attaching carbon black (with a particle size of 45 nm) to polyester fibers by a filling method; the length of the conductive fiber is 42 mm and the fineness is 3.2 dtex;

[0086] Insulating clothing fiber: Cotton fiber; the length is 28 mm and the fineness is 1.32 dtex;

[0087] (2) After the conductive fiber and the insulating clothing fiber respectively go through the carding and drawing processes, a uniform conductive fiber sliver and an insulating clothing fiber sliver are formed. After the conductive fiber sliver and the insulating clothing fiber sliver are respectively drawn out from their respective cans, they are respectively held by their respective feed rollers and feed plates; after the two fiber slivers are actively transported forward by their respective feed rollers, they are respectively combed by two independent carding rollers to form two fiber streams. After the two fiber streams are transported through their respective corresponding fiber conveying channels, they respectively enter the condensing groove of the rotor from the fiber outlet of the two fiber conveying channels to form a condensed beard. The condensed beard is twisted by the high-speed rotation of the rotor and then led out by the yarn guide roller and wound into a blended conductive yarn;

[0088] Let the feeding speed of the feed roller corresponding to the conductive fiber be u x , and the feeding speed of the feed roller corresponding to the insulating clothing fiber be u y , the linear density of the yarn is T, T = 17 tex, and the yarn guide speed is V, V = 68 m·min -1 ; the mass content of the conductive fiber in the raw material is denoted as x%, x = 10, and the mass content of the insulating clothing fiber in the raw material is denoted as y%, y = 90; the quantitative value of the conductive fiber sliver corresponding to the conductive fiber is Q x , Q x = 9.9 g·(5 m) -1 , and the quantitative value of the insulating clothing fiber sliver corresponding to the insulating clothing fiber is Q y , Q y = 20.3 g·(5 m) -1 ; According to x, y, Q x , Q y , T, V, the calculated u x = 0.0584 m·min -1 , u y = 0.2563 m·min -1 ;

[0089] The rotational speed of the carding roller X corresponding to the conductive fiber is 4000 r·min -1 , and the rotational speed of the carding roller Y corresponding to the insulating clothing fiber is 6000 r·min -1 ; The rotational speed of the rotor is 65000 r·min -1; The working angle of the carding roller X is 6°, the tooth depth is 2.4 mm, and the tooth density is 12.5 teeth / (25.4 mm) 2 ; The working angle of the carding roller Y is 12°, the tooth depth is 2.5 mm, and the tooth density is 45 teeth / (25.4 mm) 2 .

[0090] Finally, the conductive fibers in the obtained blended conductive yarn aggregate in the yarn and are distributed in a three-dimensional spiral shape along the axial direction of the yarn to form a continuous conductive path, and the insulating clothing fibers closely surround and wrap the conductive fibers; the breaking strength S of the blended conductive yarn is 10.15 cN / tex, the initial modulus E is 24.86 cN / dtex, and the mass specific resistance ρ m = 0.07 Ω·g / cm 2 , and the conductivity-softness-strength index W calculated from S, E, and ρ m is 5.83.

[0091] Example 4

[0092] A preparation method of a blended conductive yarn, the specific steps are as follows:

[0093] (1) Preparation of raw materials:

[0094] Conductive fiber: Composite polyaniline conductive fiber, which is formed by attaching polyaniline (particle size of 200 nm) to polyester fiber by a filling method; the length of the conductive fiber is 58 mm and the fineness is 4 dtex;

[0095] Insulating clothing fiber: Polyester fiber; the length is 70 mm and the fineness is 4 dtex;

[0096] (2) After the conductive fibers and the insulating clothing fibers are respectively combed and drawn into strips, a uniform conductive fiber strip and an insulating clothing fiber strip are formed. After the conductive fiber strip and the insulating clothing fiber strip are respectively drawn out from their respective cans, they are respectively held by their respective feed rollers and feed plates; after the two fiber strips are actively transported forward by their respective feed rollers, they are respectively combed by two independent carding rollers to form two fiber streams. After the two fiber streams are transported through their respective corresponding fiber transmission channels, they respectively enter the condensing groove of the rotor from the fiber outlet of the two fiber transmission channels to form a condensed sliver. After the condensed sliver is twisted by the high-speed rotation of the rotor, it is drawn out by the yarn guide roller and wound into a blended conductive yarn;

[0097] Denote the feeding speed of the feed roller corresponding to the conductive fiber as u x , and the feeding speed of the feed roller corresponding to the insulating clothing fiber as u y , the linear density of the yarn is T, T = 35 tex, and the yarn guide speed is V, V = 40 m·min -1; The mass content of the conductive fiber in the raw material is denoted as x%, x = 6, and the mass content of the insulating clothing fiber in the raw material is denoted as y%, y = 94; The basis weight of the sliver corresponding to the conductive fiber is Q x , Q x = 30 g·(5 m) -1 , and the basis weight of the insulating clothing fiber sliver corresponding to the insulating clothing fiber is Q y , Q y = 30 g·(5 m) -1 ; According to x, y, Q x , Q y , T, V, the calculated u x = 0.014 m·min -1 , u y = 0.2193 m·min -1 ;

[0098] The rotational speed of the carding roller X corresponding to the conductive fiber is 5000 r·min -1 , and the rotational speed of the carding roller Y corresponding to the insulating clothing fiber is 4000 r·min -1 ; The rotational speed of the rotor is 25000 r·min -1 ; The working angle of the carding roller X is 7°, the tooth depth is 2.1 mm, and the tooth density is 12 teeth / (25.4 mm) 2 ; The working angle of the carding roller Y is 15°, the tooth depth is 2.7 mm, and the tooth density is 65 teeth / (25.4 mm) 2 .

[0099] In the finally obtained blended conductive yarn, the conductive fibers aggregate in the yarn and are distributed in a three-dimensional spiral shape along the axial direction of the yarn, forming a continuous conductive path, and the insulating clothing fibers closely surround and wrap the conductive fibers; The breaking strength S of the blended conductive yarn is 11.84 cN / tex, the initial modulus E is 30.27 cN / dtex, and the mass specific resistance ρ m = 0.15 Ω·g / cm 2 , and the conductivity-softness-strength index W calculated from S, E, and ρ m is 2.61.

[0100] Example 5

[0101] A method for preparing a blended conductive yarn, the specific steps are as follows:

[0102] (1) Preparation of raw materials:

[0103] Conductive fiber: Silver-plated polyester conductive fiber, which is formed by attaching silver-plated particles (particle size of 223 nm) to polyester fibers by a coating method; The length of the conductive fiber is 18 mm, and the fineness is 1.3 dtex;

[0104] Insulating clothing fiber: viscose fiber; length 38 mm, fineness 1.36 dtex;

[0105] (2) After the conductive fiber and the insulating clothing fiber respectively go through the carding and drawing processes, a uniform conductive fiber sliver and an insulating clothing fiber sliver are formed. After the conductive fiber sliver and the insulating clothing fiber sliver are respectively drawn out from their respective cans, they are respectively held by their respective feed rollers and feed plates; after the two fiber slivers are actively transported forward by their respective feed rollers, they are respectively combed by two independent carding rollers to form two fiber streams. After the two fiber streams are transported through their respective corresponding fiber transmission channels, they respectively enter the condensing groove of the rotor from the fiber outlet of the two fiber transmission channels to form a condensed beard. The condensed beard is twisted by the high-speed rotation of the rotor and then led out by the yarn guide roller and wound into a blended conductive yarn;

[0106] Denote the feeding speed of the feed roller corresponding to the conductive fiber as u x , and the feeding speed of the feed roller corresponding to the insulating clothing fiber as u y , the linear density of the yarn is T, T = 70 tex, and the yarn guide speed is V, V = 120 m·min -1 ; the mass content of the conductive fiber in the raw material is denoted as x%, x = 7, and the mass content of the insulating clothing fiber in the raw material is denoted as y%, y = 93; the fixed quantity of the conductive fiber sliver corresponding to the conductive fiber is Q x , Q x = 3 g·(5 m) -1 , and the fixed quantity of the insulating clothing fiber sliver corresponding to the insulating clothing fiber is Q y , Q y = 18.53 g·(5 m) -1 ; According to x, y, Q x , Q y , T, V, the calculated u x = 0.977 m·min -1 , u y = 2.1 m·min -1 ;

[0107] The rotational speed of the carding roller X corresponding to the conductive fiber is 6000 r·min -1 , and the rotational speed of the carding roller Y corresponding to the insulating clothing fiber is 9000 r·min -1 ; the rotational speed of the rotor is 150000 r·min -1 ; the working angle of the carding roller X is 6°, the tooth depth is 2.2 mm, and the tooth density is 14 teeth / (25.4 mm) 2 ; the working angle of the carding roller Y is 12°, the tooth depth is 2.5 mm, and the tooth density is 45 teeth / (25.4 mm) 2。

[0108] In the finally obtained blended conductive yarn, the conductive fibers aggregate in the yarn and are distributed in a three-dimensional spiral shape along the axial direction of the yarn, constructing a continuous conductive path, and the insulating clothing fibers closely surround and wrap the conductive fibers; the breaking strength S of the blended conductive yarn is 17.33 cN / tex, the initial modulus E is 42.18 cN / dtex, and the mass specific resistance ρ m = 0.11 Ω·g / cm 2 , and the conductivity-softness-strength index W calculated from S, E, and ρ m is 3.74.

[0109] Example 6

[0110] A preparation method of a blended conductive yarn, the specific steps are as follows:

[0111] (1) Preparation of raw materials:

[0112] Conductive fiber: a composite graphene conductive fiber, which is formed by attaching graphene (particle size of 2.3 μm) to polyester fiber by a coating method; the length of the conductive fiber is 38 mm, and the fineness is 2.5 dtex;

[0113] Insulating clothing fiber: recycled cotton fiber; the length is 18 mm, and the fineness is 1.3 dtex;

[0114] (2) After the conductive fibers and the insulating clothing fibers are respectively combed and drawn into strips, a uniform conductive fiber strip and an insulating clothing fiber strip are formed. After the conductive fiber strip and the insulating clothing fiber strip are respectively drawn out from their respective cans, they are respectively held by their respective feed rollers and feed plates; after the two fiber strips are actively transported forward by their respective feed rollers, they are respectively combed by two independent carding rollers to form two fiber streams. After the two fiber streams are transported through their respective fiber transmission channels, they respectively enter the condensation groove of the rotor from the fiber outlet of the two fiber transmission channels to form a condensed sliver. The condensed sliver is twisted by the high-speed rotation of the rotor and then drawn out by the yarn guide roller and wound into a blended conductive yarn;

[0115] Denote the feeding speed of the feed roller corresponding to the conductive fiber as u x , and the feeding speed of the feed roller corresponding to the insulating clothing fiber as u y , the linear density of the yarn is T, T = 50 tex, and the yarn guide speed is V, V = 70 m·min -1 ; the mass content of the conductive fibers in the raw materials is denoted as x%, x = 8.5, and the mass content of the insulating clothing fibers in the raw materials is denoted as y%, y = 91.5; the quantitative value of the conductive fiber strip corresponding to the conductive fiber is Q x , Q x = 5.65 g·(5 m)-1 The specified weight per unit length of the insulating textile fiber sliver corresponding to the insulating textile fiber is Q y Q y = 3 g·(5 m) -1 ; According to x, y, Q x 、Q y 、T、V, the calculated u x = 0.263 m·min -1 u y = 5.33 m·min -1 ;

[0116] The rotational speed of the carding roller X corresponding to the conductive fiber is 4000 r·min -1 The rotational speed of the carding roller Y corresponding to the insulating textile fiber is 4000 r·min -1 ; The rotational speed of the rotor is 70000 r·min -1 ; The working angle of the carding roller X is 9°, the tooth depth is 2.4 mm, and the tooth density is 13 teeth / (25.4 mm) 2 ; The working angle of the carding roller Y is 12°, the tooth depth is 2.5 mm, and the tooth density is 45 teeth / (25.4 mm) 2 .

[0117] In the finally obtained blended conductive yarn, the conductive fibers aggregate in the yarn and are distributed in a three-dimensional spiral shape along the axial direction of the yarn to form a continuous conductive path, and the insulating textile fibers closely surround and wrap the conductive fibers; the breaking strength S of the blended conductive yarn is 14.18 cN / tex, the initial modulus E is 23.81 cN / dtex, and the mass specific resistance ρ m = 0.03 Ω·g / cm 2 , and the conductivity-softness-strength index W calculated from S, E, and ρ m is 19.85.

Claims

1. A method for preparing a blended conductive yarn, characterized in that: Conductive fiber and insulating clothing fiber are used as raw materials, and the blended conductive yarn is prepared by double-feed double-combing rotor spinning process. In the raw material, the content of the conductive fiber is 5 to 10 wt%; The conductivity-softness-strength index W of the blended conductive yarn is 1.7 to 19.85, and the conductivity-softness-strength index W is defined as: In the formula, W is in units of (cm 2 ) / (10·Ω·g); S is the breaking strength, in cN / tex; E is the initial modulus, in cN / dtex; ρ m is the mass specific resistance, unit is Ω·g / cm 2 ; The specific preparation process is as follows: the conductive fiber and the insulating serving fiber are respectively subjected to the combing and drawing process to form uniform conductive fiber slivers and insulating serving fiber slivers, and the conductive fiber slivers and the insulating serving fiber slivers are respectively drawn out from their respective sliver cans and then held by their respective feeding rollers and feeding plates; the two fiber slivers are actively conveyed forward by their respective feeding rollers, and then combed by two independent combing rollers to form two fiber streams, and the two fiber streams are transported through their respective corresponding fiber delivery channels, and then enter the condensation groove of the rotor from the fiber outlets of the two fiber delivery channels to form condensed whiskers, and the condensed whiskers are twisted by the high-speed rotation of the rotor, and then drawn out by the yarn drawing roller and wound into a blended conductive yarn; The speed of the combing roller X corresponding to the conductive fiber is 4000~6000r·min -1 ; The working angle of the combing roller X is 6°~9°, the tooth depth is 2.1~2.4mm, and the tooth density is 12~16 teeth / (25.4mm) 2 .

2. The method for preparing a blended conductive yarn according to claim 1, characterized in that: The length of the conductive fiber is 18 to 58 mm, and the fineness is 1.3 to 4 dtex; the length of the insulating clothing fiber is 18 to 70 mm, and the fineness is 1.3 to 4 dtex.

3. The method for preparing a blended conductive yarn according to claim 1, characterized in that: The conductive fiber is a composite conductive fiber, which is formed by attaching conductive particles or conductive materials to insulating fibers by filling or coating; the insulating clothing fiber is one or more of natural fibers and chemical fibers.

4. The method for preparing a blended conductive yarn according to claim 1, characterized in that: The feeding speed of the feeding roller corresponding to the conductive fiber is u x The feeding speed of the feeding roller corresponding to the insulating fiber is u y The linear density of the yarn is T, the yarn delivery speed is V, and the quantity of the conductive fiber strips corresponding to the conductive fiber is Q x The quantity of insulating fiber strips corresponding to the insulating fiber is Q y , T ranges from 14 to 70 tex, Q x and Q y The value range is 3~30g·(5m) -1 , the value range of V is 40~120m·min -1 ,u x The value range is u x >0,u y The value range is u y >0.

5. The method for preparing a blended conductive yarn according to claim 4, characterized in that: The speed of the combing roller Y corresponding to the insulating clothing fiber is 4000~9000r·min -1 ; Rotor speed is 25000~150000r·min -1 .

6. The blended conductive yarn prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The conductive fibers in the blended conductive yarn are gathered in the yarn and distributed in a three-dimensional spiral along the axial direction of the yarn to form a continuous conductive path, and the insulating clothing fibers tightly surround and wrap the conductive fibers.

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