Abstract: A progressive die for forming a turbulator having multiple rows of axial corrugations. The corrugations are slit and offset such that artificial turbulence is generated as it passes through the corrugations. The device includes a plurality of dies disposed along an axial material direction. A flat strip of material enters the dies and is folded about its longitudinal axis in a relatively wide V-fold. As the strip of material moves forward, it is intermittently stamped in the series of dies. The initial dies create a central V-shaped fold that gradually narrows into a U-shaped channel with straight walls. Once the first corrugation is formed, a series of progressive dies form the remaining corrugations in alternating fashion. Next, the material moves through a slitting station that provides apertures and an axial offset such that adjacent sections of the corrugation are slit and offset in the axial direction.

Abstract: A progressive die for forming a turbulator having multiple rows of axial corrugations. The corrugations are slit and offset such that artificial turbulence is generated as it passes through the corrugations. The device includes a plurality of dies disposed along an axial material direction. A flat strip of material enters the dies and is folded about its longitudinal axis in a relatively wide V-fold. As the strip of material moves forward, it is intermittently stamped in the series of dies. The initial dies create a central V-shaped fold that gradually narrows into a U-shaped channel with straight walls. Once the first corrugation is formed, a series of progressive dies form the remaining corrugations in alternating fashion. Next, the material moves through a slitting station that provides apertures and an axial offset such that adjacent sections of the corrugation are slit and offset in the axial direction.