Patent ID: 8281489

Claim:
A method of forming a heat exchanger tube, the method comprising: providing a first sheet of material extending along a first longitudinal direction; providing a second sheet of material extending along a second longitudinal direction; transporting the first sheet of material along a first path using a first drive; transporting the second sheet of material along a second path using a second drive; shaping a longitudinal edge of the first sheet of material while transporting the first sheet of material; shaping a plurality of longitudinally-extending peaks and valleys into the second sheet of material while transporting the second sheet of material to produce an insert for the heat exchanger tube; perforating a first location at which the first sheet of material will be separated; perforating a second location at which the second sheet of material will be separated; after perforating the first and second locations, adjusting at least one of a speed of the first drive to adjust a speed of the first sheet of material with respect to the second sheet of material and a speed of the second drive to adjust a speed of the second sheet of material with respect to the first sheet of material to longitudinally align the first and second locations to desired positions relative to one another during transport; inserting a longitudinal edge of the second sheet of material into the shaped longitudinal edge of the first sheet of material; enclosing the insert within walls of the tube defined at least in part by the first sheet of material; and separating the walls of the tube with the enclosed insert from upstream portions of the first and second sheets of material at the first and second locations during transport of the first and second sheets of material.