Research And Design On Compound Winding Control System For PET Coated Film

PET(Poly Ethylene Terephthalate)coater is a production equipment which is responsible for compounding the coated PET and PE(Poly Ethylene). In the PET coated film production progress, the tension control effects the quality of PET coated film directly. Tension changes will reduce film quality and even the scrap, and affect the production efficiency. In order to get high quality and high efficiency production of PET coated products, it’s necessary to optimize the tension control and speed control to guarantee dynamic performance in PET coating compounding winding process.The paper started with the production process of coater to study the key factors in the process of unwinding and rewinding unit of PET coater, and to determine final design scheme by means of analysing its characteristics, performance and production. According the different control requirements of each production process, adopted the means of independent adjustment and subsection control, combination direct tension control with sensorless indirect tension control to achieve the best combination result by taking the appropriate control model towards each process period.To overcome the shortcomings of complex structures, different film elongation and poor drying effect, this paper designed a tension control system without sensor to achieve precision control of the compound section tension. Through studying the dynamic mechanical analysis of compound technology, estimating the tension model, and realizing indirectly tension control by controlling vacuum adsorption motor’s output speed and torque. The coated compound machine’s vacuum adsorption and compound sections were driven by high-performance AC vector inverter drive to achieve high accuracy tension control. Unwinding unit adopted high-performance AC vector inverter and bearing type tension detector to achieve constant tension control, while rewinding unit adopted high-performance AC vector inverter, electromagnetic proportional valve and floating roller to achieve taper tension control. Parameters online modifying and real-time monitoring of the entire production process parameters by using humanized human-computer interface.Finally, according to the technological requirements, a practical PET coated film compound winding control system was designed, the system is suitable for the thickness of 25 microns PET film and 10 microns PE film, and the width is 2 m. The maximum compound speed is 120 m/min.