Development of Computer-Aided Control Systems for Polymer Extrusion and Spinning Processes

塑化挤出机在聚合物加工工业中有着广泛的应用。这对稳定挤出速率是非常重要的，即：例如，为了保证挤出机的生产率，以达到高质量的产品和高生产率，挤出机的生产率是不可缺少的。然而，在生产线上，挤出速率无法在线测量。为了控制挤出速率并生产出高质量的产品，需要一种估计器，该估计器可以通过二次测量变量（如螺杆转速、料筒温度、料筒压力等）来预测挤出速率，而目前在工业上还没有，本研究的主题之一是估计器的开发。通过对实验数据的多元统计分析和时间序列分析，明确了挤出速率与挤出机其它变量之间的关系，建立了挤出速率的静态/动态预测模型。估计器由两部分组成。第一个是稳态单元，可以计算挤出速率的平均值;另一个是动态单元，可以预测挤出速率的动态行为，其在稳态单元的值附近波动。通过模拟实验验证了该估计器的预测性。另一个主题是分析了氟碳树脂在挤出过程中可以观察到的几种现象：在氟碳树脂的挤出过程中，挤出材料的表面在一定的生产量范围内是光滑的。这种现象被称为超剪切。通过多次实验，找到了在超剪切条件下实现稳定加工的重要因素。

Plasticating extruder has a wide range of applications in the polymer processing industry. It is very important in stabilizing the extrusion rate, i. e., to maintain the throughput rate of extruder in order to achieve high quality products and high productivity.On the production line, however, extrusion rate can not be measured on-line. In order to control the extrusion rate and to produce high quality products, it is necessary to have an estimator, currently unavailable in the industry, that can predict the extrusion rate by secondary measured variables, such as the rotation rate of the screw, the temperature of the cylinder, the pressure of the cylinder and so on.One of topics in this research is the development of the estimator. By applying the melhods of multivariate statistical analysis and time series analysis to experimentally obtained data, relationships between the extrusion rate and the other variables of the extrude have been made clear and a static/dynamic model for estimating the extrusion rate has been developed. The estimator consists of two parts. The first is a steady element that can calculate the average value of extrusion rate ; the other is a dynamic element that can predict the dynamic behavior of the extrusion rate, which fluctuates around the value from the steady element. Some simulation has been performed to validate the predictability of the estimator.Another topic is the analysis of several phenomena that one can observe when the fluorocarbon resins are processed by the extruder.In the extrusion process of the fluorocarbon resins, the surface of the extruded material is smooth at certain region of throughput. That phenomena is called super-shear. We find important factors of realizing stable processing in the super-shear condition, by conducting the several experiments.