First of all, the choice of raw materials is very important. The length, uniformity and impurity content of fiber will affect the effect of vortex spinning. If the fiber is too short or uneven, it is easy to disperse unevenly during transportation, resulting in yarn details. Therefore, the selection and treatment of fibers should be emphasized.
Then comes the opening and combing process. If these two steps are not sufficient, there are fibers that are not completely separated in the fiber bundle, or there are impurities, details will be formed during subsequent twisting. It is necessary to ensure that the fibers are fully loosened, combed evenly, and impurities are eliminated. The process parameter setting of vortex spinning itself is also very important. Such as airflow speed, spinning tension, nozzle structure and so on. If the high-speed air flow is not properly controlled, it may lead to uneven distribution of fibers, and the tension instability will also affect the evenness of yarn formation. The appropriate parameters need to be adjusted to ensure stable twisting of the fiber in the vortex field.
Temperature and humidity control is also a factor. The textile shop usually needs to control temperature and humidity, because the physical properties of the fiber are affected by the environment. Low humidity may cause static electricity of fibers, which is difficult to control. Too high may affect the fluidity of the fiber. Maintaining the right temperature and humidity will help reduce details.
Equipment maintenance is equally important. The wear of nozzles, leakage of air flow and other problems will affect the spinning effect. Regular inspection and maintenance of equipment to ensure that the components are in top condition can reduce yarn defects caused by equipment problems.
In addition, the monitoring and detection system functions. On-line monitoring can detect yarn problems in real time, adjust process parameters in time, and avoid batch quality problems. It is necessary to recommend the use of advanced monitoring technology to improve the accuracy of process control.
Finally, the comprehensive application of these measures is summarized, emphasizing the systematic optimization rather than the adjustment of a single factor. As an expert, you need to give structured and well-organized advice covering raw materials, processes, equipment, environment and many other aspects to ensure that the answer is both professional and practical. In vortex spinning process, to reduce yarn details (such as hair, thick knots, details, cotton knots, etc.), it is necessary to systematically control from multiple aspects such as raw material selection, process optimization and equipment regulation. The following are the key points from the perspective of textile engineering
Measures: 1. Pretreatment of fiber raw materials Fiber length and uniformity: The raw materials with regular fiber length (such as CV≤28%) and low short pile rate (≤10%) are preferred to reduce the weak yarn ring caused by uneven fiber dispersion. Impurities and dust control: Through fine cotton opening and efficient dust removal (such as multi-bin cotton mixing + metal/dust separator), to ensure the cleanliness of the fiber (containing impurities ≤0.8%), to avoid impurities interfering with the stability of the vortex field. 2. Pre-spinning process reinforcement carding machine high-precision carding: using tin - cover plate spacing 5-7‰ inch, needling roller - tin speed ratio ≥2.2, to ensure single fibrosis rate > 85%, reduce fiber entanglement caused by details. Parallel quantitative gradient design: the final parallel quantitative is 8-12% lower than the head, maintaining the range of 6.0-6.5ktex, and improving the dry uniformity of the strip (U%≤3.2%) through three merging steps. 3. Vortex spinning core parameters optimization nozzle pressure gradient control: the pressure of the main nozzle is set at 0.45-0.55MPa, and the pressure gradient of the auxiliary nozzle is decreased by 10-15% to ensure that the fiber bundle is evenly spread in the vortex chamber.
Spinning negative pressure dynamic regulation: Adjust the negative pressure value according to the yarn count (such as 40Ne yarn count corresponding to -650Pa), maintain ±2% pressure fluctuation through the PID closed-loop system, and suppress the airflow turbulence. Guide needle geometry parameter matching: the guide needle cone Angle is selected to be 60°±2°, and the needle tip is 0.3-0.5mm away from the inlet of the spindle, so that the fiber can accurately lead into the vortex field. 4. Online monitoring and intelligent regulation CCD yarn defect real-time detection: Deploy 8-channel HD camera (resolution ≥5μm/pixel), combined with AI algorithm for the diameter deviation > ±30% of the details of real-time alarm and link to adjust the draft multiple. Eddy current field temperature compensation: the infrared temperature control module is installed to maintain the temperature of the spinning area at 28±1℃ and the humidity at 65±3%RH to eliminate the fluctuation of fiber static electricity and holding force caused by temperature change. 5. Equipment maintenance standardized eddy current chamber periodic cleaning: every 48h using ultrasonic + compressed air (0.3MPa) dual-mode cleaning, control chamber volume dust < 0.1g/m³. Spindle concentricity calibration: The laser alignment instrument is used every week to ensure that the radial runout of the spindle is less than 0.005mm, to prevent the eccentric vibration caused by the periodic uneven yarn. Through the system integration of the above technical means, the detail incidence rate (IPI value) of vortex spinning yarn can be reduced to less than 5% of Uster level, and the strength and elongation of yarn can be significantly improved (such as breaking strength CV≤8%, detail-50% cross section /km≤15). It should be noted that different fiber types (such as polyester/viscose blend) should be targeted to adjust the eddy current field parameters, and it is recommended to establish a process response surface model through DoE experimental design to achieve dynamic optimization.