Research And Development Of Extrude Based On PLC Control System

Producing a plastics silk with good function, not only want the right usage raw material, but also need the process equipments and the craft parameters to choose to use very key. In fact, the produce is subjected to the screw stem electrical motor, the degree of humidity, machine tube temperature, the characteristic of the material process, export the pressure etc. Because of the influence of many factors, unsteadies of the plastics product exists in the quantity.What this system adopts is the machine system of a single screw stem to extrude. In regard to process equipments and parameters to choose, the single screw stem machine to extrude is simple most. The parameter regulate also is the most convenient to set, and simple and easy to reform, is wide in adaptability of operation, so the equipment will get the most extensive application.The plastics extruding system is the control system that takes PLC as to control the control system of the core. After the compare between the PLC control system and relay control system, computer control system, DCS control system deeply, and according to actual request, the control system is decided to adopt to take the PLC as control core, which makes the control centralized management, maintain and maintenance convenience, and the price is lower.The system's temperature control is adopted the PID fuzzy control. During produce procedure, the time constant of the plastics extruding is big, pure delay is long and the coupling is strong. The highly nonlinear of the temperature control process, dynamic state mutability, multi time dimensions, information complexities, the dispersion of sensing component and execution unit and the layering dispersion of the decision agency decide it is hard to use the precise mathematics model token to characterize. The adoption of PID the fuzzy control can adjust controlled variable, according to the pervious setting control regulation, without intermission and automatically, to make control system to transit to the setting balanced state during control process. This system samples four points to control the temperature in heat process. The control accuracy is in 3℃, which strengthen the credibility and the anti- interference abilities of the system and can satisfy the demand of the production nicely.Synthesizing above contents, this text analyzed control system design and the development trends currently on the domestic and international single screw stem extruding machine, and made sure the system constitute: taking PLC as the core, to make temperature and the electrical motor speed concentrated control; with the mutual machine of the touch panel monitoring temperature motor speed. The temperature control adopts the fuzzy calculate PID.