A Network-Theory-Based Comparative Study of Melt-Conveying Models in Single-Screw Extrusion: A. Isothermal Flow
A Network-Theory-Based Comparative Study of Melt-Conveying Models in Single-Screw Extrusion: A. Isothermal Flow
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DOI：
10.3390/polym10080929
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发表时间：
2018-08-01
期刊：
影响因子：
5
通讯作者：
Miethlinger, Juergen
中科院分区：
文献类型：
--
作者：
Marschik, Christian;Roland, Wolfgang;Miethlinger, Juergen
在许多挤出过程中，计量部分是螺杆的速率控制部分。在这个功能区，聚合物熔体被加压，并准备好通过口模泵送。我们最近提出了一套启发式模型来预测幂定律流体在二维和三维计量通道中的流动行为。这些新颖的理论消除了对数值模拟的需要，并且易于在实践中实现。在这里，我们提出了一个对比研究，旨在验证这些新方法与实验数据。在一台仪器齐全的实验室单螺杆挤出机上进行了广泛的实验，使用了不同的材料、螺杆设计和工艺条件。用MatLab编写了基于网络理论的模拟程序，模拟了硅胶计量段的流动情况。三维启发式熔体输送模型对螺杆轴向压力分布的预测与实验数据吻合较好。为了证明新的熔体流动理论的有效性，我们还将这些模型与文献中已知的修正的牛顿泵送模型进行了比较。
In many extrusion processes, the metering section is the rate-controlling part of the screw. In this functional zone, the polymer melt is pressurized and readied to be pumped through the die. We have recently proposed a set of heuristic models for predicting the flow behavior of power-law fluids in two- and three-dimensional metering channels. These novel theories remove the need for numerical simulations and can be implemented easily in practice. Here we present a comparative study designed to validate these new methods against experimental data. Extensive experiments were performed on a well-instrumented laboratory single-screw extruder, using various materials, screw designs, and processing conditions. A network-theory-based simulation routine was written in MATLAB to replicate the flow in the metering zones in silico. The predictions of the three-dimensional heuristic melt-conveying model for the axial pressure profile along the screw are in excellent agreement with the experimental extrusion data. To demonstrate the usefulness of the novel melt-flow theories, we additionally compared the models to a modified Newtonian pumping model known from the literature.