Abstract: A plurality of press devices 2 are arranged in a plastic working system. The plastic working system includes: a loop correction sensor 13 for watching a slack of a coil material C intermittently delivered from a preceding first press device 2a; and a second slack watching means 19 for watching a slack of the coil material C generated at the time of sending the coil material C to a succeeding second press device 2b. According to the slack generated by intermittent feeding of the coil material C sent from the first press device 2a, intermittent feeding is converted to continuous feeding by the feeding means 15. At the same time, the continuous feeding speed is subjected to speed increasing/decreasing control. On the other hand, by the second slack watching means 19, a slack of the coil material C is watched at the time of feeding the coil material C to the second press device 2b and the preceding first press device 2a is subjected to speed increasing/decreasing control.

Abstract: A plurality of press devices 2 are arranged in a plastic working system. The plastic working system includes: a loop correction sensor 13 for watching a slack of a coil material C intermittently delivered from a preceding first press device 2a; and a second slack watching means 19 for watching a slack of the coil material C generated at the time of sending the coil material C to a succeeding second press device 2b. According to the slack generated by intermittent feeding of the coil material C sent from the first press device 2a, intermittent feeding is converted to continuous feeding by the feeding means 15. At the same time, the continuous feeding speed is subjected to speed increasing/decreasing control. On the other hand, by the second slack watching means 19, a slack of the coil material C is watched at the time of feeding the coil material C to the second press device 2b and the preceding first press device 2a is subjected to speed increasing/decreasing control.