Preparation method of antistatic array spinning composite yarn

Abstract

The invention relates to a preparation method of an antistatic array spinning composite yarn, which comprises the following steps of: performing array ionization on a spinning solution, and performing subsequent spinning by taking a web as a receiving matrix to obtain the composite yarn. The prepared yarn has good and efficient antistatic performance, the preparation mode is simple, and large-scale preparation of the antistatic wool yarn can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of textiles, and specifically relates to a method for preparing antistatic array-spun composite yarn. Background Technology

[0002] Static electricity is extremely common in wool fabrics, a result of the unique physical structure and chemical composition of wool fibers. The surface of wool fibers is covered with tile-like scales, leading to a large difference in the coefficients of friction between the forward and reverse sides of the fiber surface. This makes it easy for charge transfer and static electricity to accumulate when the fibers rub against each other or with other materials. The hydrophobic lipid layer makes it difficult for this static charge to dissipate. In dry environments, this static electricity is particularly pronounced, with accumulated static voltage reaching up to 10kV, which can cause a noticeable electric shock and severely impact the wearing experience.

[0003] Currently, the main methods for antistatic treatment of wool fibers include blending conductive fibers and antistatic finishing of fabrics. Among them, blending conductive fibers involves adding a certain amount of conductive fibers during the blending stage, and conducting and dissipating static charges through the charge conduction mechanism. The products obtained by this process have good washability, but the antistatic effect is related to the proportion of conductive fibers. Moreover, the differences in bending stiffness, moisture absorption and other properties between fibers will weaken the soft hand feel and dyeing uniformity of the blended products. Patent CN202450234U discloses an antistatic fabric in which milk silk and wool silk are intertwined to form the total yarn, with conductive fiber yarns mixed in between. Conductive fibers effectively dissipate static electricity from the human body, giving fabrics antistatic properties. However, the resulting blended wool fabrics will weaken the unique softness and drape of natural wool. Antistatic finishing involves padding the fabric with surfactants. This method is inexpensive and simple, but its antistatic effect depends on environmental humidity, and its wash fastness is low, making it difficult to fully meet the demands of high-performance, durable antistatic wool products in actual production. Patent CN104294604A discloses an antistatic finishing process for wool fabrics, including steps such as soaking in a first finishing solution, first tumble drying, soaking in a second finishing solution, second tumble drying, drying, and shearing and steaming. Wool fabrics produced by antistatic finishing processes have good stability, but poor wash fastness because most antistatic agents are only physically adsorbed and fixed on the fiber surface, and are largely lost after several washes, significantly reducing the antistatic effect.

[0004] Electrospun nanofibers have advantages such as high specific surface area, high surface energy, and easy functionalization, which can create conditions for the realization of antistatic function and the enhancement of inter-dielectric bonding. The paper "Preparation of high-performance composite materials by electrospinning and their performance research" (Yu Luping, Sichuan University, 2022) proposed a method that can simultaneously improve the air permeability, moisture absorption and quick drying and antistatic properties of electrospun polyacrylonitrile nanofibers. However, their mechanical properties are inferior to those of wool fibers, which greatly limits their application in functional textiles. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing antistatic array-spun composite yarn.

[0006] To address the shortcomings of existing technologies, this invention aims to solve the deficiencies of traditional wool antistatic treatments, including poor fabric feel and surfactant adhesion. It provides a method for preparing antistatic array-spun composite yarn. Array spinning refers to adding a needle-free array ionization device during the combing stage of the spinning process to composite array-ionized nanofibers with wool fibers. These composites then enter the sliver process, where the sliver undergoes drawing, carding, combing, roving, and spinning to produce the composite yarn. Based on the array spinning process, an in-situ composite antistatic fiber is designed to prepare antistatic blended wool yarn. The spatial distribution of antistatic nanofibers within the yarn constructs an electrostatic dissipation network, and their size advantage ensures effective and robust bonding with the wool fibers. This method has significant application potential in practical production.

[0007] This invention provides a method for preparing composite yarn, comprising:

[0008] (1) Mix the polymer, solvent and antistatic functional agent to obtain the spinning solution;

[0009] (2) The spinning solution is ionized in an array and a wool web is used as the receiving substrate to obtain an antistatic array-spun composite wool top, which is then spun to obtain a composite yarn.

[0010] Preferably, in step (1), the polymer is polyacrylonitrile PAN (Mw80000-100000); and the solvent is N,N-dimethylformamide DMF.

[0011] Preferably, the antistatic functional additive in step (1) is a mixture of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate SN and 1-butyl-3-methylimidazolium hexafluorophosphate IL.

[0012] The main component of the octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate (SN) is a quaternary ammonium salt. As a cationic surfactant, SN's hydrophilic quaternary ammonium salt and hydroxyl groups can adsorb water molecules in the environment, forming a nanoscale hydration layer on the material surface. Furthermore, the quaternary ammonium salt ionizes to generate mobile cations (R-N). ＋ ) and anions (NO3) - H in the hydration layer ＋ OH - and free NO3 - R-N ＋ This forms an ion-conducting network, reduces the surface resistance of the fiber, accelerates surface charge leakage, and thus reduces the possibility of excessive static charge accumulation and discharge; the imidazole cations in IL react with PF6. - When anions completely dissociate under solvent-free conditions, they form freely moving ion pairs, which can improve the ability to conduct electrostatic charge. The two together form a dual antistatic mechanism.

[0013] Preferably, the mass ratio of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate SN to 1-butyl-3-methylimidazolium hexafluorophosphate IL is (1~3):1.

[0014] Preferably, the concentration of polymer in the spinning solution in step (1) is 8-15 wt%; and the amount of antistatic functional additive is 8-20 wt%.

[0015] In step (1), the polymer is dissolved in a solvent, and then 6-15 wt% of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate SN is added relative to the total mass of the solution and stirred until completely dissolved. Then, 2-6 wt% of 1-butyl-3-methylimidazolium hexafluorophosphate (IL) is added relative to the total mass of the solution and stirred for 20-30 min to obtain the spinning solution.

[0016] Preferably, the process parameters for array ionization in step (2) are: ambient temperature of 18-28℃, ambient relative humidity of 10%-30%, array ionization receiving distance of 15-30cm, applied voltage of 40-65kV, and liquid supply rate of 0.4-0.8rmp / min.

[0017] Preferably, the web in step (2) is a wool web.

[0018] Preferably, spinning is carried out in step (2), and the spinning solution is arrayed and ionized at the same time. A wool web is used as the receiving substrate. The wool web is closely attached to the receiving device. After array ionization, the composite fiber web continues to be transported along the conveyor screen. Then it is gathered into a strip through the gathering port, pressed and converged by the pressing roller, and then subjected to subsequent spinning processes including drawing, combing, combing, roving and spinning processes to obtain composite yarn.

[0019] In step (2), an antistatic wool top is obtained through an array spinning device, which consists of a web conveying device, a needleless array ionization device, and a gathering device. The web conveying device consists of a conveying screen and a conveying roller, and the conveying screen is made of plain nylon fabric. The needleless array ionization device consists of a high-voltage power supply and a generating device, and the generating device is a copper disc nozzle. The gathering device is composed of a hollow truncated cone and is responsible for gathering the web into a top.

[0020] In step (2), the composite yarn is an array-spun composite wool yarn with antistatic function.

[0021] The present invention provides a composite yarn prepared by the method described in claim 1.

[0022] This invention provides an application of the composite yarn in the field of antistatics.

[0023] This invention involves the following processes: wool fiber combing, array ionization, drawing, carding, combing, roving, and spinning, to produce array-spun wool yarn with antistatic properties. The yarn prepared by this method exhibits excellent and efficient antistatic properties, and the preparation method is simple, enabling the mass production of antistatic wool yarn.

[0024] This invention prepares an antistatic micro / nanofiber spinning solution by mixing octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate (SN) with 1-butyl-3-methylimidazolium hexafluorophosphate (IL) and adding the mixture to an electrospinning solution. The micro / nanofibers are then combined with the wool web across scales using an array ionization method. The resulting array-spun composite wool yarn with antistatic function is then produced through subsequent drawing, combing, combing, roving, and spinning processes. This method cleverly combines array ionization technology with traditional spinning. Array ionization is performed during the wool fiber carding and web formation stage, using the wool web as the receiving matrix. This achieves cross-scale composite of micro / nanofibers and wool fibers. Subsequent spinning steps facilitate the transfer of micro / nanofibers within the yarn, achieving a uniform distribution of micro / nanofibers in the three-dimensional space of the yarn. Furthermore, the addition of SN and IL endows the micro / nanofibers with antistatic properties. SN completely dissociates in the spinning solution, providing two types of free ions. These ions embed within the PAN fibers, forming ion conduction channels and also providing hydroxyethyl groups to enhance hygroscopicity. The addition of IL creates free charge carriers within the nanofibers, enabling directional conduction and migration of static charges, forming more conductive paths and reducing the resistivity of the nanofibers. The nanofibers can construct a three-dimensional conductive network within the yarn structure, improving the electrostatic problem of wool yarn.

[0025] Beneficial effects

[0026] (1) This invention prepares antistatic functional nanofibers and embeds them into hair fibers using an array ionization process, which overcomes the defects of the prior art and achieves efficient and stable antistatic effect.

[0027] (2) The method for preparing antistatic functional nanofibers disclosed in this invention can be achieved using conventional equipment and production lines. Only an array ionization device needs to be added in the spinning and combing stage. It requires less capital investment, consumes less energy, has high preparation efficiency and finished product qualification rate, is easy to operate and control, and is suitable for continuous large-scale production.

[0028] (3) The raw materials used in this invention, such as polyacrylonitrile, octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate, and 1-butyl-3-methylimidazolium hexafluorophosphate, are widely available, green, healthy and chemically stable, which significantly reduces production costs. The antistatic wool yarn made from these materials is safe and environmentally friendly and does not affect the softness, skin-friendly comfort of the wool fabric itself.

[0029] (4) This invention matches the antistatic functional additives with nanofibers by adjusting the process parameters and applies them to array spinning. By utilizing the size difference between micro / nanofibers and wool fibers, the antistatic functional additives are better embedded into wool fibers across scales to achieve the antistatic effect. Attached Figure Description

[0030] Figure 1 This is a flowchart of the process for preparing antistatic array ionization composite wool yarn;

[0031] Figure 2 This is a schematic diagram of the array ionization cross-scale fiber composite process;

[0032] Figure 3 This is a schematic diagram of the array spinning device;

[0033] In the diagram: 1. High-voltage power supply; 2. Needle-free array ionization device; 3. Conveyor shaft; 4. Conveyor screen; 5. Gathering device;

[0034] Figure 4 This is an image showing the appearance morphology of the antistatic array-spun composite wool yarn prepared in Example 1. Detailed Implementation

[0035] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0036] Polyacrylonitrile (PAN) (powder, Mw85000, Shanghai Chemical Fiber Group); N,N-dimethylformamide (DMF) (analytical grade, Shanghai Lingfeng Chemical Reagent Co., Ltd.); 1-Butyl-3-methylimidazolium hexafluorophosphate (IL) (analytical grade, Shanghai Maclean Chemical Reagent Co., Ltd.); Octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate (SN) (analytical grade, Shanghai Maclean Chemical Reagent Co., Ltd.).

[0037] Example 1

[0038] S1: Dissolve 2g of PAN (Mw85000) in 18g of DMF and stir at room temperature for 10h to obtain a spinning polymer solution.

[0039] S2: Add 2g of SN to the spinning polymer solution prepared in S1 and stir until completely dissolved. Then add 1g of IL and continue stirring for 30 minutes to form a homogeneous mixture to obtain the electrospinning solution.

[0040] The wool web is used as the receiving substrate for array ionization. The wool web is tightly fitted to the receiving device. After the array ionization step, the composite fiber web continues to be transported along the conveyor screen, then gathered into a sliver at the gathering point, pressed and converged by the compression roller, and finally processed through subsequent drawing, carding, combing, roving and spinning processes to obtain the multi-scale composite array spun wool yarn. The array ionization process parameters used are: ambient temperature of 25℃, relative humidity of 15%, array ionization receiving distance of 20cm, spinning voltage of 40kV, and liquid supply rate of 0.4rpm / min.

[0041] Example 2

[0042] S1: Dissolve 2g of PAN (Mw85000) in 18g of DMF and stir at room temperature for 10h to obtain a spinning polymer solution.

[0043] S2: Add 3g of SN to the spinning polymer solution prepared in S1, and continue stirring for 30 minutes to form a uniform mixture to obtain the electrospinning solution.

[0044] The wool web is used as the receiving substrate for array ionization. The wool web is tightly fitted to the receiving device. After the array ionization step, the composite fiber web continues to be transported along the conveyor screen, then gathered into a strip at the gathering port, pressed and converged by the compression roller, and finally processed through subsequent strip, carding, combing, roving and spinning processes to obtain the multi-scale blended yarn. The array ionization process parameters used are: ambient temperature of 25℃, relative humidity of 15%, array ionization receiving distance of 20cm, spinning voltage of 40kV, and liquid supply rate of 0.4rpm / min.

[0045] Example 3

[0046] S1: Dissolve 2g of PAN (Mw85000) in 18g of DMF and stir at room temperature for 10h to obtain a spinning polymer solution.

[0047] S2: Add 3g of IL to the spinning polymer solution prepared in S1, and continue stirring for 30 minutes to form a uniform mixture to obtain the electrospinning solution.

[0048] The wool web is used as the receiving substrate for array ionization. The wool web is tightly fitted to the receiving device. After the array ionization step, the composite fiber web continues to be transported along the conveyor screen, then gathered into a strip at the gathering port, pressed and converged by the compression roller, and finally processed through subsequent strip, carding, combing, roving and spinning processes to obtain the multi-scale blended yarn. The array ionization process parameters used are: ambient temperature of 25℃, relative humidity of 15%, array ionization receiving distance of 20cm, spinning voltage of 40kV, and liquid supply rate of 0.4rpm / min.

[0049] Comparative Example 1

[0050] A pure wool yarn, which undergoes basically the same spinning steps as those in Examples 1, 2, and 3, except that it does not undergo the array separation step, but only the traditional spinning steps such as combing, drawing, carding, combing, roving, and spinning processes.

[0051] Performance tests were conducted on Examples 1-3 and Comparative Example 1, respectively. The surface morphology of the yarns of Examples 1, 2, and 3 was observed using a scanning electron microscope. Submicron fibers exist in the yarn body in the form of adhering to the surface of wool fibers and filling the pores of wool fibers. The difference between the two across scales makes the impact on the macroscopic morphology of the yarn insignificant. Moreover, compared with the traditional method of blending conductive fibers, the addition of submicron fibers does not damage the hand feel of the yarn and does not affect the softness and skin-friendly comfort of the wool fabric itself.

[0052] To further illustrate the unexpected positive technical effects achieved by the products of the various embodiments of the present invention, the antistatic performance of the antistatic array ionization composite wool yarns prepared in each example was tested according to AATCC 84-2018. The results are shown in Table 1, and the specific test methods are as follows:

[0053] Place the yarn sample in a stable contact with the electrode, ensuring the yarn direction is perpendicular to the adjacent edge of the electrode. Apply sufficient current to straighten the yarn strands. Test the resistance of the sample according to the operating instructions and procedures of the ohmmeter used. Pass the current through the sample for at least 1 minute until a constant reading is reached. Where R is the resistivity of each yarn strand (Ω / cm), S is the number of yarn strands in each sample, D is the distance between electrodes (cm), r is the resistance of each sample containing S strands, and n is the total number of samples.

[0054] As can be seen from Table 1, the antistatic array-spun composite wool yarn disclosed in the embodiments of the present invention has superior antistatic properties compared with the comparative product.

[0055] Table 1

[0056]

Claims

1. A method for preparing a composite yarn, comprising: (1) Mix the polymer, solvent and antistatic functional agent to obtain the spinning solution; (2) The spinning solution is arrayed and ionized, and a wool web is used as the receiving matrix for subsequent spinning to obtain composite yarn.

2. The preparation method according to claim 1, characterized in that, In step (1), the polymer is polyacrylonitrile (PAN); the solvent is N,N-dimethylformamide (DMF).

3. The preparation method according to claim 1, characterized in that, The antistatic functional additive in step (1) is a mixture of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate SN and 1-butyl-3-methylimidazolium hexafluorophosphate IL.

4. The preparation method according to claim 3, characterized in that, The mass ratio of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate SN to 1-butyl-3-methylimidazolium hexafluorophosphate IL is (1~3):

1.

5. The preparation method according to claim 1, characterized in that, The concentration of polymer in the spinning solution in step (1) is 8-15 wt%; the amount of antistatic functional additive added is 8-20 wt%.

6. The preparation method according to claim 1, characterized in that, The process parameters for array ionization in step (2) are: ambient temperature of 18-28℃, relative humidity of 10%-30%, array ionization receiving distance of 15-30cm, applied voltage of 40-65kV, and liquid supply rate of 0.4-0.8rmp / min.

7. The preparation method according to claim 1, characterized in that, In step (2), the mesh is a wool mesh.

8. The preparation method according to claim 1, characterized in that, In step (2), the spinning solution is array-ionized and a wool web is used as the receiving substrate. The wool web is tightly attached to the receiving device. After array ionization, the composite fiber web continues to be transported along the conveyor curtain. Then it is bundled into strips through the gathering port, pressed and gathered by the pressing roller, and then spun into composite yarn. The subsequent spinning processes include drawing, combing, combing, roving, and spinning.

9. A composite yarn prepared by the method of claim 1.

10. The application of the composite yarn of claim 9 in the field of antistatic properties.

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