plate bending machine for ventilation duct

the production of elbow parts for air ducts starts with a rollforming proc-ess. this operation seams the blank and creates one part for the lock. in the second step the internal and outside elbow duct cheeks will be round......the production of elbow parts for air ducts starts with a rollforming proc-ess. this operation seams the blank and creates one part for the lock. in the second step the internal and outside elbow duct cheeks will be rounded on the requested radius. traditional rounding machines use one part rolls. since the part comes with the rollformed seam, traditional rounding machines can offer only some poor and costly compromises. setting the rolls to the seam thickness results in poor radii. stronger settings will damage the seam and in the long term also the rolls. the ras ventirounder for the air duct production rounds sheet metal elbow cheeks with pre-formed snap lock or pittsburgh seams. the result are perfect workpieces without the need of additional spacer parts. after having moved the rounding rings along the working length and set them to the approximate blank width, you can start rounding the blank. the rings round the sheet metal without touching the seams. therefore the seams keep their geometry during the rounding process. a gear-brake motor with variable speed can be operated from a single phase outlet.