Polymer Extrusion: From Control System Design to Product Quality

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• 作者：Zhijun Jiang ; Yi Yang ; Shengyong Mo ; Ke Yao ; Furong Gao
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：November 14, 2012
• 年：2012
• 卷：51
• 期：45
• 页码：14759-14770
• 全文大小：720K
• 年卷期：v.51,no.45(November 14, 2012)
• ISSN：1520-5045

文摘

As a major polymer processing technique, polymer extrusion is a continuous process, during which material properties, machine variables, and process variables interact with each other to determine the final product quality. Precise control of key process variables such as barrel temperatures and melt pressure are crucial to ensure a good product quality in the extrusion process. In this paper, the overall extruder control system is constructed by two independent control loops, a single-input鈥搒ingle-output (SISO) control of the melt pressure at die output, and a multiinput鈥搈ultioutput (MIMO) control of the barrel temperatures. The dynamic behaviors of melt pressure and barrel temperatures were analyzed first. The characteristics of the melt pressure dynamics were as follows: nonlinear and time-varying while the extruder barrel temperatures were nonlinear, slow response, and different zones were highly coupled. Advanced control algorithms were adopted to control these key variables. Experimental results demonstrate the fast response, near-zero overshoot, and precise tracking performance of the proposed control strategies. The robustness of the entire control system was verified through different operating conditions including materials and set points. Ultimately the performance of the entire control system was verified by product quality. The product quality improved significantly with the proposed controller.