light industry

First, the foreword
Coater needs to glue or ink material uniformly adhesion on the surface of aluminum foil and plastic film or cloth textiles, on coating process requirements is relatively high, not only the requirements of coating highly uniform and be able to achieve high-speed non-stop roll changing in order to improve the production efficiency.
Two, coating machine control requirements
Coating machine steps are generally divided into: constant tension roll, coating process of multi synchronous control, constant tension winding several links. In the normal production process, the base material tension is constant, the line speed is constant, the start and stop process is smooth. So in the control of the mechanical and electrical properties of the coating machine, the key is to control the tension of the coating machine system. Because of the size of the tension directly affects the quality and quantity of products, tension is too large, will destroy the physical properties of the coated paper, and quality of life of the paper influence; tension is too small, are too loose, paper is not smooth, will affect the follow-up process, and the quality of products. In the whole process, regardless of starting and accelerating, downtime reduction, any line speed constant speed operation are required to roll coating, composite roller and traction and keep the line running speed synchronization, otherwise there will be a paper breaking, winding displacement, aluminum foil folds or printing fault patterns, such as abnormal. In this process, it is required that the compound coating motor speed control is fast, the speed control is accurate, the tension fluctuation is small.

1, the traditional program
The tension control of the system is to control the tension stability by controlling the speed of the system. The industry is use high grade PLC to constant line speed control and the folded volume traction and winding and unwinding device of pendulum and potentiometer feedback signals sent to the PLC, by PLC and PID control coil diameter calculation, the results through analog to vector converter. Inverter in the entire control system is just an actuator. The PLC operation speed fast and needs to be extended to more of a / D and D / a module, and because of the effects of the PLC operation speed and signal transduction, making dynamic system response slow, so can only use the vector frequency converter in the high-end brand, requirements inverter simulation input mouth has a high resolution, frequency dynamic response fast and high precision of steady speed, to compensate for the delay caused due to lack of program.
2, Yi chuangfei inverter scheme:
(1) the brief introduction of a Yi chuangfei vector converter
David chuangfei vector control inverter is a new domestic high-end inverter in recent years. ECF500 universal vector transducer and ECF300 tension control special vector transducer. ECF500 powerful, and can achieve closed-loop vector control, to meet the current requirements of most of the industry on the function and performance of the inverter. ECF300 is a tension transducer controller, which is mainly used in the calculation of roll diameter, tension taper and other tension control. Torque mode and speed mode of tension control of ECF300. The tension control accuracy requirements of the high speed mode, the tension control accuracy requirements of the occasion, you can use the torque mode, the system structure is simple and easy to debug.
(2) control points
Each section of the line at a constant speed, but due to the winding and rewinding process in roll diameter changes constantly, PID regulation must consider velocity variations due to changes in the volume size, otherwise it will destroy the physical properties of the coated paper, and quality of life of the influence of paper, such a requirement in steady speed precision, and the system dynamic response speed.
Three, program advantages
1, constant tension control, synchronous control is completed by the inverter, do not need an external controller, the control system using PLC control, simple structure.
2, constant tension control, production process tension is very constant, high control precision, the substrate will not be damaged, the coating effect is even, the product quality is good.
3, through the rolling taper compensation adjustment, the finished product to close the tension constant, completely avoid the condition of the inside tight loose.
4, technology is mature, debugging, operation, maintenance is very convenient.

  

Four, structure
1, the substrate volume phase need a ECF500 series power retractable line converter, mainly to substrate constant tension as the goal by closed-loop PID automatic control, line speed followed by leading change speed change; when a loose line, the line speed follow breathe linear velocity changes and changes; when a break occurs, line dish immediately stop operation, due to the wire disc brake and parking at the inverter to set for free parking, the whole volume of the process run independently.
2, coating and drying stage need more open loop vector control inverter, using proportional control, in the coating machine production process of the main signal and fine adjustment signal according to the superposition operation. Method for the realization of linear speed synchronization: multi stage synchronous control of multi stage coating process for example, in order to achieve the line speed to keep synchronization, using the frequency of the auxiliary frequency phase superposition method. Synchronous control in the first inverter frequency rate through the RS485 communication transmission to the second, and so on, until the last one, through the communication mode of operation frequency transmission, can avoid the attenuation of the analog signal in the transmission process, each one inverter aided frequency for each inverter frequency trimming, by inverter rising / falling operating frequency. Fine tuning frequency accuracy up to 0.01Hz.
3, the finished product winding volume phase requires a ECF300 tension control special inverter, mainly to finished product constant tension as the goal, the open loop control automatically taper calculation, coil diameter calculation, without tension is applied to the device, the coating machine production of finished products are volume phase tracking operation.