The mill was put into production in Huaxi Cold Strip Steel Plant in May, 2001.and has the following features:

• A hydraulic screw down system for each stand. The system is composed of an accurate closed loop position control (APC) and an accurate closed loop rolling force control (AFC) carried out by a Siemens S7-400 PLC

• Position sensing with Balluff micropulse transducers

• AGC system reaches the accuracy of the strip thickness by 0.003mm

• Rolling speed is 5m/s
• APC and AFC is automatically switched on line without any impact

The mill was put into production in the Aluminum Industrial Company in Henan province, July, 2001.

The system adopts a Siemens 6RA70 drives and S7-400 series PLCs, Balluff micropulse transducer for position measuring of the hydraulic screw down, an isotope gauge meter to detect thickness of the foil. Rolling parameters can be set up and displayed on the operating screen OP270

Electrical control cabinet of tension roller control system

With rapid respond speed and control precision of the hydraulic screw down, s7-400 high capacity PLC and software gained Ihroug many years research, the company has developed a series of AGC equipments used in rolling mills und closed loop elongation control equipments used for temper mill.

AGC system has severed kinds of control modes such as pre-control, monitor, flow veloity control, tension AGC and so on. The closed loop thickness control can be realized through affecting the parameter of hydraulic screw down, including roller gap. rolling force, reel tension and so on. The target precise can reach ±I%.