In recent years, with the rapid development of China's infrastructure, there is also a huge demand for spunbond non woven fabric. At present, it still occupies most of the market share in China and has a broad prospect. However, there are still some problems of technological lag and product quality defects in the specific production. This paper introduces how to optimize the electrical control of spunbond non woven production line.
In order to ensure the single fiber strength index of spunbond non woven fabric, it is necessary to accurately control the drying temperature, crystallization temperature and melting temperature of sliced pet. The PLC integrated temperature module is selected to collect the temperature in real time, and the PLC output module outputs high-frequency pulse to control the solid-state relay to achieve the purpose of accurate temperature control, which can greatly prolong the service life of electrical components, avoid serious temperature lag, significantly improve the temperature stability and accuracy, and control the temperature deviation within ± 0.1 ℃.
Fiber drafting is an important link in the production of spunbond non woven fabric, which directly affects the breaking strength, elongation at break and shrinkage of polyester filament. Polyester filament is air draft, so the precise control of air pressure determines the quality of draft. Collect the real-time air pressure signal and send it to PLC. Through PLC programming PID automatic adjustment, output analog signal to control the pneumatic diaphragm valve. The control pressure is more than 5 bar. The air pressure control is accurately and effectively completed. The control accuracy is less than ± 1%, and the product quality is greatly improved.
At present, the key difficulty in the production of spunbond non woven fabric lies in the smooth feeding of reinforcing materials, which requires controlling the speed between each roll, so as to control the tension and reduce the wire breakage rate. The feeding part is selected as multiple sets of servo control yarn guide rollers. The control hardware mainly includes: programmable logic controller (PLC), servo driver and servo motor. No sensor is required, which effectively avoids the serious lag of the system. In addition, a series of parameters such as acceleration and deceleration time and torque curve of servo motor are set by using special software, and the relevant parameters of parameter servo driver are optimized. Through the real-time adjustment of the torque of the servo motor, the speed between the rollers is accurately controlled, so that the yarn is uniform and stable, and the average fiber tension is 60-66cn. Finally, the key problem of thread breaking is solved.
Considering the economy, control accuracy and other aspects, the stepper motor is selected to achieve accurate position control. In order to improve the market competitiveness of spunbond non woven fabric production line, we should not blindly pursue high-precision and high-stability control, but also consider economic factors and practicality.
Better control system communication can carry out data transmission quickly and accurately, successfully avoid the impact of external factors on system stability, and control the stable operation of equipment, so as to produce high-quality spunbond non woven fabric. Taking Siemens PLC PLC as an example, the signal transmission is completed by using high anti-interference Ethernet communication, which not only makes the transmission data and signals not easy to interfere, but also reduces the wiring, greatly simplifies the programming, and improves the transmission rate from Kbps to Mbps. In addition, the system is controlled by the touch screen. Through configuration, the real-time torque parameters and real-time speed parameters of the three main yarn rollers can be set and fed back. The operation main touch screen also includes protection functions such as interlock protection and safety emergency stop, which greatly facilitates the process personnel to adjust the process parameters. At the same time, DCS decentralized control is adopted, the signals are uniformly connected to the industrial route, and the remote monitoring and field state adjustment are realized through the Internet, Greatly reduce the later maintenance cost.
Of course, when optimizing the electrical control of the spunbond non woven fabric production line, we should also consider the accuracy of mechanical design and the rationality of process parameters, so that all disciplines can cooperate with each other to create a continuously improved non-woven fabric production line, so that the spunbond non woven fabric can be better developed.