Effects of Compatibilizer and Airflow Field on the Formation of Helical Microfibers via Melt Blowing

2019 ◽  
Vol 57 (21) ◽  
pp. 1423-1433
Author(s):  
Hui Li ◽  
Hui Huang ◽  
Yongchun Zeng
Keyword(s):  
Melt Blowing ◽  
Airflow Field

Study on airflow field and fiber motion with new melt blowing die

2019 ◽  
Vol 59 (6) ◽  
pp. 1182-1189 ◽  
Author(s):  
Wanli Han ◽  
Sheng Xie ◽  
Jing Shi ◽  
Xinhou Wang
Keyword(s):  
Melt Blowing ◽  
Fiber Motion ◽  
Airflow Field

Turbulence of melt-blowing airflow field: Comparison of a convergent jet and a typical free jet

2021 ◽  
Vol 33 (7) ◽  
pp. 075107
Author(s):  
Ying Yang ◽  
Hui Huang ◽  
Yongchun Zeng
Keyword(s):  
Melt Blowing ◽  
Free Jet ◽  
Airflow Field

Effect of slot end faces on the three-dimensional airflow field from the melt-blowing die

2020 ◽  
Vol 40 (7) ◽  
pp. 607-613
Author(s):  
Yudong Wang ◽  
Jianping Zhou
Keyword(s):  
Numerical Calculation ◽  
Flow Field ◽  
Field Distribution ◽  
Three Dimensional ◽  
Central Area ◽  
Computational Domain ◽  
Melt Blowing ◽  
Slot Die ◽  
Calculation Results ◽  
Airflow Field

AbstractIn order to investigate the effect of the slot ends of the melt-blowing die on the three-dimensional airflow field distribution and the fiber draft, the numerical calculation was carried out. The computational domain of the slot die was established with Gambit, and the flow field was calculated using FLUENT. Compared with the experimental data collected by a hot-wire anemometer, the numerical calculation results are credible. The results show that the slot end face has a certain influence on the three-dimensional flow field distribution under the melt-blowing die. The air velocity and temperature in the center region are quite different from those near the slot-end face. As the distance from the center of the flow field increases, the velocity and temperature on the spinning line begin to decrease. The velocity and temperature distributions of the spinning lines in the central area and nearby areas are almost the same; the temperature and velocity values on the spinning lines near the slot end are the lowest. The distribution characteristics of the three-dimensional airflow field could affect the uniformity of the fiber diameter and the meltblowing products.

scholarly journals Measurement and Comparison of Melt-Blowing Airflow Fields: Nozzle Modifications to Reduce Turbulence and Fibre Whipping

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 719
Author(s):  
Ying Yang ◽  
Yongchun Zeng
Keyword(s):  
Turbulence Intensity ◽  
Temperature Fluctuation ◽  
High Speed ◽  
Aerodynamic Force ◽  
High Speed Photography ◽  
Melt Blowing ◽  
Fluctuation Intensity ◽  
Slot Die ◽  
Turbulent Airflow ◽  
Airflow Field

In the melt-blowing process, micro/nanofibrous nonwovens are attenuated and formed through aerodynamic force in a turbulent airflow field. In this work, two types of airflow-directors were added under a common melt-blowing slot-die nozzle to obtain modified airflow fields. The effect of airflow-directors on time-averaged characteristics, turbulence intensity, and temperature fluctuation intensity are achieved through the simultaneous measurement of fluctuating velocity and fluctuating temperature using a two-wire probe hot-wire anemometer. Moreover, the influence of airflow-directors on fibre oscillations are also investigated through high-speed photography. The distribution of turbulence intensity and temperature fluctuation intensity reveals the characteristics of fluctuating airflow fields formed by different melt-blowing slot-die nozzles. Through the analyses of airflow characteristics and fibre oscillations, we can find that the arrangement of airflow-directors has a great impact on both turbulence distribution and fibre oscillation.

Numerical evaluation of contaminants mixing uniformity in a full-scale test chamber with mixing fan

2020 ◽  
pp. 1420326X2097902
Author(s):  
Hai-Xia Xu ◽  
Yu-Tong Mu ◽  
Yin-Ping Zhang ◽  
Wen-Quan Tao
Keyword(s):  
Concentration Distribution ◽  
Test Chamber ◽  
Full Scale ◽  
Numerical Results ◽  
Test Method ◽  
Test Accuracy ◽  
Full Scale Test ◽  
Concentration Region ◽  
Airflow Field ◽  
Scale Test

Most existing models and standards for volatile organic compounds emission assume that contaminants are uniform in the testing devices. In this study, a three-dimensional transient numerical model was proposed to simulate the mass transport process based on a full-scale test chamber with a mixing fan, and the airflow field and contaminants concentration distribution were obtained within the chamber under airtight and ventilated conditions. The model was validated by comparing the numerical results with experimental data. The numerical results show that the contaminant source position and the airflow field characteristics have significant impact on the contaminant mixing, and the fan rotation has an important role in accelerating mixing. In the initial mixing stage, the concentration distribution is obviously uneven; as the mixing progresses, it gradually reaches acceptable uniformity except for some sensitive regions, such as high concentration region at the injection point of the contaminants and low concentration region at the air inlet. To ensure test accuracy, the monitor should avoid above sensitive regions; and some special regions are recommended where contaminant concentration uniformity can be reached sooner. The ventilated chamber results indicate that the mixture of contaminants in the chamber is actually better than the results shown by conventional test method.

Effect of position of the fiber transport channel on fiber motion in the high-speed rotor

2021 ◽  
pp. 004051752110018
Author(s):  
Rui Hua Yang ◽  
Chuang He ◽  
Bo Pan ◽  
Hongxiu Zhong ◽  
Cundong Xu
Keyword(s):  
High Speed ◽  
Channel Model ◽  
Three Dimensional ◽  
Discrete Phase Model ◽  
Transport Channel ◽  
Rotor Spinning ◽  
Fiber Motion ◽  
Discrete Phase ◽  
Airflow Field ◽  
Fiber Transport

The task of the fiber transport channel (FTC) is to transport the fibers from the carding roller to the rotor. Its geometric position in the spinning machine has a strong influence on the characteristics of the airflow field and the trajectory of the fiber motion in both the rotor and the FTC. In this paper, a three-dimensional pumping rotor spinning channel model was established using ANSYS-ICEM-CFD software with three different positions of the FTC (positions a–c). Further, the simulations of air distribution were performed using Fluent software. In addition, the discrete phase model was used to fit the fiber motion trajectory in the rotor. The simulation results showed that among the three types of FTC, position b is the optimal condition. The gradients of airflow velocity in the channel at position b were greater than those of the other two positions, which is conducive to straightening of the fiber.

Numerical investigation on a melt-blowing die with internal stabilizers

2019 ◽  
pp. 152808371986693 ◽  
Author(s):  
Changchun Ji ◽  
Yudong Wang ◽  
Yafeng Sun
Keyword(s):  
Average Velocity ◽  
Fiber Diameter ◽  
Measurement Data ◽  
Melt Blowing ◽  
One Dimensional ◽  
Temperature Decay ◽  
Slot Die ◽  
The Common ◽  
The One ◽  
Peak Value

In order to decrease the fiber diameter and reduce the energy consumption in the melt-blowing process, a new slot die with internal stabilizers was designed. Using computational fluid dynamics technology, the new slot die was investigated. In the numerical simulation, the calculation data were validated with the laboratory measurement data. This work shows that the new slot die could increase the average velocity on the centerline of the air-flow field by 6.9%, compared with the common slot die. Simultaneously, the new slot die could decrease the back-flow velocity and the rate of temperature decay in the region close to the die head. The new slot die could reduce the peak value of the turbulent kinetic energy and make the fiber movements more gradual. With the one-dimensional drawing model, it proves that the new slot die has more edge on the decrease of fiber diameter than the common slot die.

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