Abstract:

Based on the programmable logic controller （PLC）and the MODBUS industrial communication network techonlogy, an automatic control system is developed which can add functional masterbatch for the spinning raw materials flow. Different measured signals from production field transmitters are sent to the PLC through the MODBUS network. According to technological process and requirements of the dynamic mixer equipment, the PLC calculates appropriate control signals using some modern control algorithms. And the signals are sent to the inverters or other control equipments through the MODBUS network as well. The system is a part of the spinning process control system, having changed the situation that the functional masterbatch only can be added evenly in unit capacity, realized real-time dynamic evenly adding. The system also can automatically change the injection rate and injection ratio in real time constant according with spinning equipment states. Moreover, the system has solved the response lag problem of the original instrument control system. Practical application effects show the quality and stability of the spinning process improved.