Particle Image Velocimetry (PIV) Investigation of the Turbulent Airflow in Slot-Die Melt Blowing.

Sheng Xie,Guojun Jiang,Baoqing Shentu,Baolin Ye

doi:10.3390/polym12020279

Abstract

In order to explore the forming mechanism of the fiber whipping motion in slot-die melt blowing, the turbulent airflow in slot-die melt blowing was measured online with the approach of the Particle Image Velocimetry (PIV) technique. The PIV results visualized the structure of the turbulent airflow and provided the distributions of air velocity components (vx, vy, and vz). Moreover, the PIV results also demonstrated the evolutive process of turbulent airflow at successive time instants. By comparing the characteristics of the turbulent airflow with the fiber whipping path, the PIV results provide a preliminary explanation for the specific fiber whipping motion in slot-die melt blowing.

Highlights

Melt-blown microfibers with a mean diameter of several micrometers are obtained by attenuating the polymeric melt jets with the help of a high-speed air stream [1], and the melt-blown micro-fibrous materials are widely used in areas of filtration and oil/water separation [2,3]
The present work focused on experimental exploring of the turbulent airflow in slot-die melt blowing, and the ultimate goal of this work is to explain the discovered fiber whipping motion [25]
The turbulent airflow in slot-die melt blowing was measured with the approach of Particle Image Velocimetry (PIV)

Summary

Introduction

Melt-blown microfibers with a mean diameter of several micrometers are obtained by attenuating the polymeric melt jets with the help of a high-speed air stream [1], and the melt-blown micro-fibrous materials are widely used in areas of filtration and oil/water separation [2,3]. The second generation of equipment measuring the melt-blown airflow are the laser doppler velocimeter and hot-wire anemometer [12,13]. These two pieces of equipment could measure the airflow with a higher air velocity. The diffusion angle of the airflow in slot-die melt blowing was tentatively measured using a dual-probe hot-wire anemometer, and the results showed that the lateral velocity component was significant for initiating fiber whipping [16]

Objectives

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Results

Conclusion