Study On Control System Of PTFE Fiber Paste Preparation Technology By Extrusion

Polytetrafluoroethylene fiber has excellent physical and chemical properties.At present,the preparation methods of polytetrafluoroethylene fiber include paste extrusion,membrane splitting,carrier spinning,etc.the paste extrusion method is the main method to prepare polytetrafluoroethylene fiber with mature and excellent fiber properties,which can be used to prepare polytetrafluoroethylene solid fiber and hollow fiber membrane.The paste extrusion method has higher requirements for the control of production process parameters,especially the extrusion pressure directly affects the fiber fineness uniformity,which is one of the most important parameters.However,the current paste extrusion method for the production of polytetrafluoroethylene fiber has low degree of automation and poor control of process parameters,which restricts the improvement of product quality.Focusing on the key technology of preparing polytetrafluoroethylene fiber by paste extrusion,this paper designs an automatic control system with self-tuning extrusion pressure from the innovative design and optimization of the control system.The production process of polytetrafluoroethylene fiber by paste extrusion method is studied,the specific content and control deficiencies of the existing process are analyzed,and the automation improvement scheme is proposed,which provides the basis for the design of the overall electrical automation control.In order to improve the control accuracy of extrusion pressure,this paper proposes to use direct drive pump to control the electro-hydraulic servo system to provide thrust for extruder,and establish a mathematical model for the extrusion system.The control theory of classical PID control and fuzzy control is analyzed.The extrusion pressure is controlled by the fuzzy self-tuning PID control algorithm which combines fuzzy control with PID control.Simulation is carried out on Simulink platform of MATLAB software.The simulation results show that the control strategy has excellent response speed and dynamic response performance compared with classical PID control,It is an ideal control strategy.The automatic control system is designed for the whole production line of paste extrusion method.The Kunlun touch screen is used as the upper computer,and the MCGS configuration software is used to configure the whole production line;Mitsubishi FX series PLC is used as the central processor,and the ladder diagram is written by gxworks2,which realizes the information interaction with the upper computer and the control of hardware.The program of upper computer and PLC is programmed step by step according to the sequence of process flow,including batching system,mixing system,billet making system,extrusion system,drawing sintering system and cutting head self stop system.The design of the automatic control system debugging,system operation stability,pressure control to achieve the desired goal,product quality and production efficiency has increased significantly.The system has a high degree of automation,simple operation and high practical value.