Controlled wrinkles are for very specific applications. In conjunction with elliptical shaped tube groove, it is generally used for making non mandrel bends with high difficulty factors. As it's name suggests, these tools help control wall thinning on the outside and thickening on the inside. This forming of the tube consumes excess material on the inside of the bend in a wrinkle pattern. If a controlled wrinkle operation bends past 160° the tooling must be split to release the tube.
For years Tube Bending Concepts has been the leader in developing this type of specialized tooling for various major manufacturers. Because of our extensive experience with controlled wrinkles, predictable first time results are typical.
Heat exchangers are the primary product for the success of wrinkled tube. The purposefully convoluted shape causes the turbulence desired to dissipate heat. Standard tubing for these applications are stainless steel or aluminized.
Wrinkle tooling is also used in making automotive exhaust. Although not flow efficient, the tooling can provide fast bending.