This review provides the current state of knowledge of steady-state modeling of the extrusion cast film process used to produce flat polymer films, as well as related experimental research with a particular focus on the flow instability neck-in. All kinematic models used (i.e., 1-, 1.5-, 2-, and 3-dimensional models) together with the utilized constitutive equations, boundary conditions, simplified assumptions, and numerical methods are carefully summarized. The effect of draw ratio, Deborah number (i.e., melt relaxation time related to experimental time), film cooling, second to first normal stress difference ratio at the die exit, uniaxial extensional strain hardening, and planar-to-uniaxial extensional viscosity ratio on the neck-in is discussed.

中文翻译：

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挤出流延薄膜工艺的稳态建模、颈缩现象及相关实验研究：综述

本综述提供了用于生产扁平聚合物薄膜的挤出流延薄膜工艺稳态建模的当前知识状态，以及相关的实验研究，特别关注流动不稳定性缩窄。所有使用的运动学模型（即 1 维、1.5 维、2 维和 3 维模型）以及所使用的本构方程、边界条件、简化假设和数值方法都经过仔细总结。拉伸比、Deborah 数（即与实验时间相关的熔体松弛时间）、薄膜冷却、模具出口处的第二与第一法向应力差比、单轴拉伸应变硬化和平面与单轴拉伸粘度比的影响讨论了缩进。