An air-jet flow field model of the dual slot die in the melt blowing nonwoven process is proposed and solved numerically with the finite difference method. The effects of dual slot dic design parameters on velocity and temperature distributions in the melt blowing flow field are investigated. The computation results of the distributions of the x-components of air velocity and air temperature coincide well with our experimental data. The results show that a smaller angle α, a larger slot width e, and a narrower head width f will all result in higher x-components of air velocity and higher e air temperatures, which are beneficial to the air drawing of the polymer melt and thus to reduced fiber diameter. The results show the great potential of this research for computer-assisted design in the melt blowing nonwoven technology.

A three-dimenslonal finite element model is developed to deal with the polymeric liquid flow in coat-hanger die. This model Is used to predict the flow behavior of the 2% CMC/watsr solution in the coat-hanger die with linearly taper manifolds and Its validity Is experimentally verified quantitatively and qualitatively by using Laser Doppler Veloclmetry and Particle Image Veloclmetry respectively.

本文基于对熔喷衣架型模头中聚合物熔体流动的三维有限元分析，给出了一种数学模型化的“试差”设计方法：以一特定的线性衣架型模头作为初始设计对象，通过不断改变其几何参数，如歧管倾斜角度和成型面高度，使之最终达到熔体横向分配均匀的设计要求。另外，本文还讨论了幂律指数对出口流率分布均匀性的影响。

将纷繁多样的衣架型模头设计理论归结为解析方法和数值方法两大类，综述了不同设计方法的设计原理以及各种设计的优点和局限性。