Ventilation duct machine The air duct production line V is composed of feeding frame, leveling and beading, hydraulic punching point and square mouth, hydraulic shearer, movable pittsburgh forming machine,feeding platform, duplex flange machine, duplex angle iron flange machine (or double snap lock machine), servo feeding platform and TDF hydraulic folding. The computer control part adopts full computer control, bending with servo feeding, accurate positioning, especially when processing the bigger air duct, to ensure the bending accuracy.