Application Of Servo System In Tension Control Of Unwinder Machine

Today, with the industrial production development, tension control is a very important process during the production. Good tension control can ensure good productivity and improve production efficiency. The thesis focuses on the tension control study and discussion for laminating unwinding machine during the BEF(Brightness Enhancement Film) manufacturing industry.Laminating unwinding machine is a non-line system with many sources of disturbance. It includes many sub process, so, it has many unpredictable factors. Unstable tension control will cause subsequent unstable cutting accuracy. With the different film diameter, the material tension changes every time during laminating machine film unwinding process. When it comes to a flexibility film, it will go into a too tie and too slack process if we cannot keep a stable unwinding tension. This status will cause product defect directly.With the development of AC variable frequency technology, it's comprehensive control ability also improved continuously. Application of this technology in laminating unwinding control system can hit the target with high accuracy as well as high stability.This thesis provides a dynamic tension control method through building the tension unwinding model, and discusses the online adjustment with incremental PID controller to meet the actual requirement of high tension control accuracy.This system uses normal Mitsubishi Q series PLC Q02CPU,combined with necessary outside and magnetic powder circuit, collects the signals from tension sensor, compares with setting values. Then, it control the actuating mechanism via amplification link after data processing which followed certain control method. Finally, it can achieve the target of tension control for film unwinding process.