Research And Exploit The Paper Drying Line Of Horizontal Two-stage Impregnation Based On Programmable Logic Controller

With the development of impregnated paper industry, the traditional paper drying line of horizontal impregnation, which is low degree of automation, using backward control technology, low efficiency, complex operation, and no enough coordination of the roller speed transmission system. The cutting precision is low. Now these shortcomings have become the bottlenecks of the impregnated paper industry of China. It is very necessary to achieve the paper drying line of horizontal impregnation online adjustment and automatic control.The paper goes deeply into analysising the theory and the process of the automatic control system of paper drying line of horizontal two-stage impregnation with the current domestic and abroad situation. This production line is using in some decoration materials Co., Ltd. of Changzhou. And we finds out much problems in equipment movement process, such as:(1) corresponding to the drive motors of the rollers coordination is not high, leading to inconsistent speed transmission of the rollers, and can not see the real-time speed of every roller. It is fully rely on the experience of workers to adjust the drive motors. (2) The cutting mechanism is controlled by the induction motors, and the induction motors are controlled by the inverter. The cutting knife is driven by its induction motor through a chain drive. The precision of the cutting is low. Location (color office) cutting can not be achieved. (3) Low efficiency of adjustment institutions, high failure rate, and big noise. (4) The operating of the production lines is complicated, and the workers work in a high labor intensity. Then we take a new design of the adjustment institutions, and the control system of the product line. Improved as follows :(1) The PLC takes precise control of each inverter through RS485 communications module. The roller speed is real-time displayed in the human machine interface, and adjustable. So that ensures coordination of the operation of rollers. (2) The cutting knife is driven by a servo motor. The PLC controls servo unit by positioning module, and improved the cutting precision. With the color sensors, the cutting knife completes the of the localization cutting. (3) Improved the adjustment institution. The adjustment institution is driven by the low-power machine permanent magnet synchronous motor. The adjustment power transmitted to the adjustment roller through the ball screw. Improved the efficiency and accuracy of the adjustment institution, reduced the failure rate, and eliminated the noise. (4) Add a human machine interface, display and set various parameters through the human machine interface. The recipe of the fans'frequency parameters is added, which is greatly reduced the labor intensity.The paper synthetically makes use of modern control elements such as programmable controller (PLC), servo module, frequency converter, encoder, human machine interface and etc. It achieves the automatic production of the paper drying line of two-stage impregnation process by a core PLC for the control, solutes the existing problems and shortcomings of the original production line, and improves the operability of the system. Compared to the original electricity control system, it is not only simplified control system and the programmable work of the customer, but also raised the accuracy, the stability, and the automatic degree of the system. It is made the scope of the production line adapt more breadth and more wide, and discarding rate is lower. It is raised the process accuracy and the product quality, bringing considerable economic performance for the enterprise, raising the market competition ability of the products, satisfying the need of different customers.