Continuous spinning process for preparing high-uniformity aramid fiber

Abstract

The invention discloses a continuous spinning process for preparing high-uniformity aramid fiber, which relates to the technical field of spinning processing and comprises the following steps: stock solution preparation and defoaming, metering and conveying, extrusion and forming, graded solidification, hot stretching and online detection and winding. The three-stage gradient coagulating bath is used for simulating fiber skin-core layer slow phase separation, a countercurrent circulation system is matched for maintaining the concentration and temperature stability of bath liquid of each layer, air layer micro-airflow disturbance inhibits solvent volatilization difference, the structure unevenness caused by too fast traditional coagulating surface is avoided, skin-core defects and surface wrinkles are reduced, and meanwhile, the surface quality is improved. An on-line detection system integrating laser scanning, infrared spectroscopy and tension sensing is used for monitoring the fiber state in real time, rapidly feeding back signals and dynamically adjusting coagulating bath, stretching and winding parameters, closed-loop control is formed, process fluctuation is restrained, consistency in batches is improved, and the rejection rate is reduced.

Description

Technical Field

[0001] This invention relates to the field of spinning technology, and more particularly to a continuous spinning process for preparing highly uniform aramid fibers. Background Technology

[0002] Aramid, also known as aromatic polyamide fiber, is a high-performance fiber with excellent properties such as high strength, high modulus, high temperature resistance, acid and alkali resistance, flame retardancy, insulation, anti-aging, and light weight. At least 85% of its molecular structure has amide bonds directly connected to aromatic rings, and this special structure endows aramid with a series of outstanding properties.

[0003] The spinning processes of aramid fibers mainly include dry spinning, wet spinning, and dry-jet wet spinning. These methods, through different spinning processes, transform aramid polymers into high-strength, high-modulus fibers. The spinning process of aramid fibers determines their excellent properties, and different spinning methods are suitable for different types of aramid fibers.

[0004] In existing technologies, the coagulation process of aramid fiber spinning often employs a single or simple two-stage coagulation bath. This is prone to problems such as large differences in fiber sheath-core structure and internal stress concentration due to uneven solvent diffusion rates. Furthermore, traditional aramid fiber spinning processes rely on offline monitoring, with parameter adjustments lagging behind the production process, making them susceptible to unstable product performance and high scrap rates due to process fluctuations. Therefore, this invention proposes a continuous spinning process for preparing highly uniform aramid fibers to address the problems existing in the prior art. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to propose a continuous spinning process for preparing highly uniform aramid fibers, thereby solving the problems of existing aramid fiber processes that are prone to large differences in fiber sheath-core structure and internal stress concentration due to uneven solvent diffusion rates, as well as the problems of unstable product performance and high scrap rate caused by process fluctuations in traditional aramid fiber spinning processes.

[0006] To achieve the objectives of this invention, the invention is implemented through the following technical solution: a continuous spinning process for preparing highly uniform aramid fibers, comprising the following steps:

[0007] Step 1: First, dissolve the aramid polymer in an amide solvent containing inorganic salts to form a homogeneous spinning solution. Then, subject the spinning solution to a three-stage gradient degassing treatment, including vacuum degassing, ultrasonic degassing, and static degassing.

[0008] Step 2: The deaerated spinning solution is delivered to the spinning assembly at constant pressure through a metering pump. The spinning assembly includes a spinneret, an air layer channel and a three-stage gradient coagulation bath along the spinning direction.

[0009] Step 3: The spinning solution is extruded through the spinneret to form a stream of nascent fibers;

[0010] Step 4: The nascent fiber streams first pass through the air layer channel with a built-in micro-airflow disturbance device for pre-evaporation, and then enter the three-stage gradient coagulation bath for staged coagulation. The three-stage gradient coagulation bath adopts a counter-current circulation system.

[0011] Step 5: The fibers exported from the three-level gradient coagulation bath enter the multi-level stretching module for synchronous hot stretching. The multi-level stretching module includes a pre-stretching zone, a main stretching zone, and a shaping zone in sequence along the fiber travel direction.

[0012] Step Six: Monitor the physical properties of the stretched fiber in real time through an online defect detection system, and adjust the process parameters of Steps One to Five accordingly. Finally, the fiber is stably wound into a cylinder.

[0013] A further improvement is that, in step one, the inorganic salt is selected from calcium chloride and lithium chloride, and the amide solvent is selected from N-methylpyrrolidone and dimethylacetamide.

[0014] The further improvement is as follows: In step one, the vacuum degree of vacuum degassing is -0.095MPa to -0.090MPa, the processing time is 20 to 40 min, the frequency of ultrasonic degassing is 20 to 40 kHz, the power density is 0.5 to 2 W / cm², the processing time is 5 to 10 min, and the static degassing is matured at a constant temperature of 30 to 50℃ and a stirring speed of 5 to 10 rpm for 2 to 4 hours.

[0015] A further improvement is that, in step four, the micro-airflow disturbance device includes a symmetrically arranged nozzle array, with the spray direction forming an angle of 45 to 90° with the fiber axis, and the solvent concentration of each bath in the countercurrent circulation system is monitored by an online conductivity meter.

[0016] A further improvement is that, in step five, the pre-stretching zone is heated by CO2 laser radiation with a wavelength of 10.6 μm, the main stretching zone includes 3 to 5 sets of hot rollers, and the shaping zone is a hot air circulating oven.

[0017] A further improvement is that, in step six, the online defect detection system includes a laser scanning unit for real-time monitoring of fiber diameter fluctuations, an infrared spectroscopy unit for analyzing fiber molecular chain orientation and crystallinity, a tension sensor for monitoring fiber running tension and feeding it back to the winding machine, and a control module for adjusting the coagulation bath temperature, the speed of the stretching hot roller, and the winding machine traction force.

[0018] A further improvement is that the airflow of the micro-airflow disturbance device is provided by a blower with a power of 5 to 15 kW and an outlet air pressure of 0.2 to 0.5 MPa, and 0.1 to 0.5 vol% dry nitrogen is added to the airflow.

[0019] A further improvement is made in the three-stage gradient coagulation bath linkage solvent recovery system, which includes a multi-effect evaporator, a molecular sieve adsorption tower, and a condensation recirculation device.

[0020] The beneficial effects of this invention are as follows: This invention proposes a three-stage gradient coagulation bath design, which simulates the slow phase separation process of fibers from the epidermis to the core layer by gradually changing the solvent concentration and temperature. This allows the solvent exchange and coagulation reaction to proceed uniformly in space, effectively avoiding the structural inhomogeneity caused by the rapid advance of the coagulation front in traditional processes. At the same time, the supporting countercurrent circulation system replenishes the final stage of the coagulation bath with fresh coagulation bath water, maintaining the long-term stability of the concentration and temperature of the bath liquid at each stage and avoiding the impact of fluctuations in bath liquid composition on coagulation consistency. Meanwhile, the micro-airflow disturbance device in the air layer channel uniformly sweeps the fiber surface with directional airflow, suppressing local differences in solvent evaporation rate and further reducing the generation of epidermal and core structural defects and surface wrinkles. This synergistic technology fundamentally solves the structural inhomogeneity problem of traditional coagulation processes and significantly improves the uniformity of the internal structure of the fiber.

[0021] Furthermore, it integrates online defect detection using laser scanning, infrared spectroscopy, and tension sensing, enabling real-time monitoring of fiber physical morphology, microstructure, and process stability across all dimensions. The detection signals are rapidly fed back through the control system (with an extremely short response time), allowing for dynamic adjustment of key process parameters such as coagulation bath temperature / concentration, stretching hot roller speed, and winding speed. This forms a closed-loop control system of monitoring, analysis, and adjustment, breaking through the limitations of traditional processes. It effectively suppresses the impact of process fluctuations on product performance in real time, significantly improving the consistency of fiber performance within and between batches, and significantly reducing the scrap rate caused by parameter deviations. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a continuous spinning process for preparing highly uniform aramid fibers according to the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Aramid fibers are a type of high-performance organic fiber produced by spinning aromatic polymers. Due to their ultra-high specific strength, specific modulus, and excellent high-temperature and chemical corrosion resistance, they are widely used in key areas such as bulletproof equipment, aerospace structural components, and industrial high-temperature protective fabrics. Para-aramid (PPTA) and heterocyclic aramids (such as PIPD and PBO) are currently the mainstream aramid varieties.

[0025] Para-aramid fibers are produced by low-temperature polycondensation reaction using p-phenylenediamine (PPD) and terephthaloyl chloride (TCl) as monomers. Their highly oriented crystalline structure, formed by rigid benzene rings and strong hydrogen bonds, endows the material with unique mechanical properties. Heterocyclic aramid fibers, on the other hand, further enhance their UV resistance and fatigue resistance by introducing heterocyclic rings (such as imidazole and piperazine) or fluorinated groups into the molecular backbone. The preparation of these fibers typically relies on solution spinning as the core process, and their performance is closely related to the orientation control of the molecular chains and the uniformity of solidification during the spinning process. Example 1

[0026] See Figure 1 This embodiment provides a continuous spinning process for preparing highly uniform aramid fibers, including the following steps:

[0027] Step 1: Preparation of stock solution and degassing

[0028] Aramid polymer was dissolved in N-methylpyrrolidone (NMP) containing calcium chloride (3% of the total mass of the spinning solution) to form a homogeneous spinning solution. The solid content of the spinning solution was controlled at 15 wt% (i.e., the mass of aramid polymer as solute accounted for 15% of the total mass of the spinning solution, and the mass of NMP as the dispersion medium accounted for 85%), and the viscosity was 2000 Pa·s. Subsequently, the spinning solution underwent a three-stage gradient degassing treatment, as follows:

[0029] Vacuum degassing, vacuum degree -0.095MPa, processing time 20min;

[0030] Ultrasonic degassing was performed at a frequency of 20 kHz, a power density of 0.5 W / cm², and a processing time of 5 min.

[0031] After standing to remove bubbles, mature at a constant temperature of 30℃ and a stirring speed of 5 rpm for 2 hours.

[0032] Step 2: Metering and Conveying

[0033] The spinning assembly used in this embodiment includes, in sequence along the spinning direction, a spinneret, an air layer channel, and a three-stage gradient coagulation bath. The length of the air layer channel is 10 cm, the internal temperature is 40°C, and the relative humidity is 30%.

[0034] When in use, the deaerated spinning solution from step two is delivered to the spinning assembly at constant pressure (pressure fluctuation ≤ ±0.1MPa) via a metering pump;

[0035] Step 3: Extrusion and Molding

[0036] The spinning solution delivered to the spinning assembly is extruded through the spinneret of the spinning assembly to form a stream of nascent fibers. The spinneret has a spinneret orifice diameter of 50 μm, an aspect ratio of 3:1, and a pore density of 100 pores / cm².

[0037] Step 4: Staged solidification

[0038] The nascent fiber streams formed in step three are first pre-evaporated through the air layer channel with a built-in micro-airflow disturbance device, and then sequentially enter the three-stage gradient coagulation bath for staged coagulation. In the three-stage gradient coagulation bath, the first stage coagulation bath is a low temperature and low solvent concentration bath (solvent mass fraction 5%, temperature 20℃), the second stage coagulation bath is a medium temperature and medium solvent concentration bath (solvent mass fraction 15%, temperature 30℃), and the third stage coagulation bath is a high temperature and high solvent concentration bath (solvent mass fraction 30%, temperature 40℃). The three-stage gradient coagulation bath adopts a counter-current circulation system. Fresh coagulation bath is added from the third stage bath and flows in the opposite direction through the second and first stage baths.

[0039] In this embodiment, the micro-airflow disturbance device includes a symmetrically arranged nozzle array with a nozzle diameter of 0.5 mm, a spray direction at an angle of 45° to the fiber axis, and an airflow velocity of 0.5 m / s. The airflow of the micro-airflow disturbance device is provided by a blower with a power of 5 kW and an outlet air pressure of 0.2 MPa. 0.1 vol% of dry nitrogen is added to the airflow to reduce the partial pressure of solvent vapor on the fiber surface and suppress local over-evaporation.

[0040] In this embodiment, in the countercurrent circulation system, the solvent concentration of each bath is monitored by an online conductivity meter. When the concentration deviation is ≥±2%, a high-concentration coagulation bath is automatically added to maintain a stable concentration gradient. The fiber residence time for each stage is 5 seconds. Adjacent baths are separated by a porous partition with a pore diameter of 0.5 mm and an opening rate of 30%.

[0041] In this embodiment, a three-stage gradient coagulation bath linked solvent recovery system is included. The solvent recovery system comprises:

[0042] Multi-effect evaporator (two stages, first stage vacuum -0.09MPa, temperature 80℃, second stage vacuum -0.095MPa, temperature 60℃);

[0043] Molecular sieve adsorption tower (filled with 5A molecular sieve, packing amount 0.5m³, adsorption temperature 30℃, space velocity 1000h⁻¹) -1 );

[0044] Condensation recirculation unit (condensation temperature 10℃, pressure 0.1MPa);

[0045] Overall solvent recovery rate ≥95%, recovered solvent purity ≥99% (inorganic salt content ≤0.1%);

[0046] Step 5: Thermal stretching

[0047] The multi-stage stretching module used in this embodiment includes, along the fiber travel direction, the following:

[0048] The pre-stretching zone is heated by CO2 laser radiation with a wavelength of 10.6μm. The heating zone is 1m long, the temperature is 100℃, and the stretching ratio is 1.2 times.

[0049] The main stretching zone includes 3 sets of hot rollers with a surface temperature of 200℃, a linear velocity gradient of 1.5 times, and a stretching ratio of 2 times.

[0050] In the setting zone, a hot air circulating oven is used with a hot air temperature of 250℃ and an air velocity of 0.5m / s. The fiber stays in this zone for 1 minute, and the relaxation rate is 1%.

[0051] In use, the fibers exported from the three-level gradient coagulation bath in step four enter the multi-level stretching module for synchronous hot stretching, with a total stretching ratio of 2 times and a stretching temperature gradient of 100℃.

[0052] Step Six: Online Inspection and Winding

[0053] The online defect detection system used in this embodiment includes:

[0054] Laser scanning unit: Employs a 650nm semiconductor laser with a scanning frequency of 1000Hz and a resolution of 0.01mm, real-time monitoring of fiber diameter fluctuations, and control of diameter non-uniformity (CV value) ≤1%;

[0055] Infrared spectral unit: Equipped with a Fourier transform infrared spectrometer (FTIR), with a detection band of 4000–400 cm⁻¹. -1 The sampling frequency was 500 Hz, and the fiber molecular chain orientation (≥85%) and crystallinity (≥80%) were analyzed.

[0056] Tension sensor: A strain gauge sensor with an accuracy of ±0.1cN is used to monitor the fiber tension and feed it back to the winding machine, controlling the winding speed error to ≤±0.5m / min;

[0057] Control module: Integrated PLC controller, after receiving signals from each unit, adjusts the solidification bath temperature, stretching hot roller speed or winding machine traction force within 0.5s;

[0058] During use, the stretched fibers in step five are monitored in real time by an online defect detection system for their physical properties (including diameter unevenness, crystallinity, and tension), and the process parameters from step one to step five are adjusted accordingly. Finally, the fibers are stably wound into a cylinder. Example 2

[0059] See Figure 1 This embodiment provides a continuous spinning process for preparing highly uniform aramid fibers, including the following steps:

[0060] Step 1: Preparation of stock solution and degassing

[0061] Aramid polymer was dissolved in dimethylacetamide (DMAc) containing lithium chloride (8% of the total mass of the spinning solution) to form a homogeneous spinning solution. The solid content of the spinning solution was controlled at 25 wt% (i.e., the mass of aramid polymer as solute accounted for 25% of the total mass of the spinning solution, while the mass of DMAc as the dispersion medium accounted for 75%), and the viscosity was 5000 Pa·s. Subsequently, the spinning solution underwent a three-stage gradient degassing treatment, as follows:

[0062] Vacuum degassing, vacuum degree -0.090MPa, processing time 40min;

[0063] Ultrasonic degassing, frequency 40kHz, power density 2W / cm², processing time 10min;

[0064] After standing to remove bubbles, it is matured for 4 hours at a constant temperature of 50℃ and a stirring speed of 10 rpm.

[0065] Step 2: Metering and Conveying

[0066] The spinning assembly used in this embodiment includes, in sequence along the spinning direction, a spinneret, an air layer channel, and a three-stage gradient coagulation bath. The length of the air layer channel is 30 cm, the internal temperature is 60 °C, and the relative humidity is 50%.

[0067] When in use, the deaerated spinning solution from step two is delivered to the spinning assembly at constant pressure (pressure fluctuation ≤ ±0.1MPa) via a metering pump;

[0068] Step 3: Extrusion and Molding

[0069] The spinning solution delivered to the spinning assembly is extruded through the spinneret of the spinning assembly to form a stream of nascent fibers. The spinneret has a spinneret orifice diameter of 100 μm, an aspect ratio of 5:1, and a pore density of 300 pores / cm².

[0070] Step 4: Staged solidification

[0071] The nascent fiber streams formed in step three are first pre-evaporated through the air layer channel with a built-in micro-airflow disturbance device, and then sequentially enter the three-stage gradient coagulation bath for staged coagulation. In the three-stage gradient coagulation bath, the first stage coagulation bath is a low temperature and low solvent concentration bath (solvent mass fraction 15%, temperature 30℃), the second stage coagulation bath is a medium temperature and medium solvent concentration bath (solvent mass fraction 30%, temperature 40℃), and the third stage coagulation bath is a high temperature and high solvent concentration bath (solvent mass fraction 50%, temperature 50℃). The three-stage gradient coagulation bath adopts a counter-current circulation system. Fresh coagulation bath is added from the third stage bath and flows in the opposite direction through the second and first stage baths.

[0072] In this embodiment, the micro-airflow disturbance device includes a symmetrically arranged nozzle array with a nozzle diameter of 2 mm, a spray direction at an angle of 90° to the fiber axis, and an airflow velocity of 2 m / s. The airflow of the micro-airflow disturbance device is provided by a blower with a power of 15 kW and an outlet air pressure of 0.5 MPa. 0.5 vol% of dry nitrogen is added to the airflow to reduce the partial pressure of solvent vapor on the fiber surface and suppress local over-evaporation.

[0073] In this embodiment, in the countercurrent circulation system, the solvent concentration of each bath is monitored by an online conductivity meter. When the concentration deviation is ≥±2%, a high-concentration coagulation bath is automatically added to maintain a stable concentration gradient. The fiber residence time for each stage is 15s. Adjacent baths are separated by a porous partition with a pore diameter of 2mm and an opening rate of 50%.

[0074] In this embodiment, a three-stage gradient coagulation bath linked solvent recovery system is included. The solvent recovery system comprises:

[0075] Multi-effect evaporator (two stages, first stage vacuum -0.09MPa, temperature 100℃, second stage vacuum -0.095MPa, temperature 80℃).

[0076] Molecular sieve adsorption tower (filled with 5A molecular sieve, 1 m³, adsorption temperature 40℃, space velocity 2000 h⁻¹) -1 );

[0077] Condensation recirculation unit (condensation temperature 20℃, pressure 0.3MPa);

[0078] Overall solvent recovery rate ≥95%, recovered solvent purity ≥99% (inorganic salt content ≤0.1%);

[0079] Step 5: Thermal stretching

[0080] The multi-stage stretching module used in this embodiment includes, along the fiber travel direction, the following:

[0081] The pre-stretching zone is heated by CO2 laser radiation with a wavelength of 10.6μm. The heating zone is 2m long, the temperature is 150℃, and the stretching ratio is 1.5 times.

[0082] The main stretching zone includes 5 sets of hot rollers with a surface temperature of 300℃, a linear velocity gradient of 2.5 times, and a stretching ratio of 3 times.

[0083] In the setting zone, a hot air circulating oven is used with a hot air temperature of 350℃ and an air velocity of 1.5m / s. The fiber stays in this zone for 3 minutes, and the relaxation rate is 3%.

[0084] In use, the fibers exported from the three-level gradient coagulation bath in step four enter the multi-level stretching module for synchronous hot stretching, with a total stretching ratio of 5 times and a stretching temperature gradient of 300℃.

[0085] Step Six: Online Inspection and Winding

[0086] The online defect detection system used in this embodiment includes:

[0087] Laser scanning unit: Employs a 650nm semiconductor laser with a scanning frequency of 1000Hz and a resolution of 0.01mm, real-time monitoring of fiber diameter fluctuations, and control of diameter non-uniformity (CV value) ≤1%;

[0088] Infrared spectral unit: Equipped with a Fourier transform infrared spectrometer (FTIR), with a detection band of 4000–400 cm⁻¹. -1 The sampling frequency was 500 Hz, and the fiber molecular chain orientation (≥85%) and crystallinity (≥80%) were analyzed.

[0089] Tension sensor: A strain gauge sensor with an accuracy of ±0.1cN is used to monitor the fiber tension and feed it back to the winding machine, controlling the winding speed error to ≤±0.5m / min;

[0090] Control module: Integrated PLC controller, after receiving signals from each unit, adjusts the solidification bath temperature, stretching hot roller speed or winding machine traction force within 0.5s;

[0091] During use, the stretched fibers in step five are monitored in real time by an online defect detection system for their physical properties (including diameter unevenness, crystallinity, and tension), and the process parameters from step one to step five are adjusted accordingly. Finally, the fibers are stably wound into a cylinder.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A continuous spinning process for preparing highly uniform aramid fibers, characterized in that, Includes the following steps: Step 1: First, dissolve the aramid polymer in an amide solvent containing inorganic salts to form a homogeneous spinning solution. Then, subject the spinning solution to a three-stage gradient degassing treatment, including vacuum degassing, ultrasonic degassing, and static degassing. Step 2: The deaerated spinning solution is delivered to the spinning assembly at constant pressure through a metering pump. The spinning assembly includes a spinneret, an air layer channel and a three-stage gradient coagulation bath along the spinning direction. Step 3: The spinning solution is extruded through the spinneret to form a stream of nascent fibers; Step 4: The nascent fiber streams first pass through the air layer channel with a built-in micro-airflow disturbance device for pre-evaporation, and then enter the three-stage gradient coagulation bath for staged coagulation. The three-stage gradient coagulation bath adopts a counter-current circulation system. Step 5: The fibers exported from the three-level gradient coagulation bath enter the multi-level stretching module for synchronous hot stretching. The multi-level stretching module includes a pre-stretching zone, a main stretching zone, and a shaping zone in sequence along the fiber travel direction. Step Six: Monitor the physical properties of the stretched fiber in real time through an online defect detection system, and adjust the process parameters of Steps One to Five accordingly. Finally, the fiber is stably wound into a cylinder.

2. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: In step one, the inorganic salt is selected from calcium chloride and lithium chloride, and the amide solvent is selected from N-methylpyrrolidone and dimethylacetamide.

3. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: In step one, the vacuum degree of vacuum degassing is -0.095MPa to -0.090MPa, the processing time is 20 to 40 min, the frequency of ultrasonic degassing is 20 to 40 kHz, the power density is 0.5 to 2 W / cm², the processing time is 5 to 10 min, and the static degassing is matured at a constant temperature of 30 to 50℃ and a stirring speed of 5 to 10 rpm for 2 to 4 hours.

4. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: In step four, the micro-airflow disturbance device includes a symmetrically arranged nozzle array, with the spray direction at an angle of 45 to 90° to the fiber axis. In the countercurrent circulation system, the solvent concentration of each bath is monitored by an online conductivity meter.

5. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: In step five, the pre-stretching zone is heated by CO2 laser radiation with a wavelength of 10.6 μm, the main stretching zone includes 3 to 5 sets of hot rollers, and the shaping zone is a hot air circulating oven.

6. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: In step six, the online defect detection system includes a laser scanning unit for real-time monitoring of fiber diameter fluctuations, an infrared spectroscopy unit for analyzing fiber molecular chain orientation and crystallinity, a tension sensor for monitoring fiber running tension and feeding it back to the winding machine, and a control module for adjusting the coagulation bath temperature, the speed of the stretching hot roller, and the winding machine traction force.

7. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: The airflow of the micro-airflow disturbance device is provided by a blower with a power of 5 to 15 kW and an outlet air pressure of 0.2 to 0.5 MPa. 0.1 to 0.5 vol% dry nitrogen is added to the airflow.

8. The continuous spinning process for preparing highly uniform aramid fibers according to claim 1, characterized in that: The three-stage gradient coagulation bath linkage solvent recovery system includes a multi-effect evaporator, a molecular sieve adsorption tower, and a condensation recirculation device.

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