Duct production line Ⅳ composed of a decoiler, leveler grooving unit, “V” and “口” notching unit, cutting unit, bending unit，reciprocating lock former unit, feed extraman unit, duplex flange (angle iron & TDF) composition, The entire production process is controlled by the servo system is completed. 

      The production line has a cover an area of small, low energy consumption, easy to move, and high efficiency, can produce a variety of rectangular duct. Control part with a separate console; the control system has a closed-loop feedback system, significantly improved accuracy and stability. Duct automated production lines feed rate of 15m / min, length tolerance is ± 0.5mm, diagonal tolerance is ± 0.8mm;