Optimal Design and Numerical Simulation of High Reliability Meltblown Die

Abstract

Abstract Double-slit nozzles are widely used in meltblown equipment. During the production process, two streams of high speed, high temperature hot air are ejected from two slits on both sides of the spinneret and converge to stretch and refine the polymer melt extruded from the spinneret. If we know the changes of airflow temperature and velocity in the flow field, we can simulate the fiber stretching and refinement process and predict the fiber properties to understand the fiber stretching mechanism, so as to guide the optimization design of meltblown process and improve the product quality and cost saving. In this thesis, a new meltblown die nozzle flow field model is developed based on the existing meltblown double-slot nozzle structure, which was improved from the theoretical model of meltblown double-slot nozzle developed by Ting Chen et al. In this thesis, the calculation area is determined and divided into meshes, and the Reynolds stress model is selected to simulate the flow field numerically, and the velocity and temperature distribution of the flow field along the axis of the spinneret is obtained.