FlexBend – Transverse-force free bending of tubes or bar material


Ref.-No. 4755

Particularly thin-walled and open profile shapes are prone to bending failures as buckling, cracking, formation of wrinkles and cross sectional deformations. In consequence, conventional bending procedures are of limited use for the manufacture of these profiles. FlexBend is a new apparatus for transverse-force free bending of tubes or bar material with an unique system for the stabilization of the cross section against deformation. With FlexBend the profile is completely supported by flexible tool shapes during the entire forming process, avoiding the twisting of asymmetrically loaded profiles and supporting the cross section actively.

Keywords: bending, tubes, profiles, transverse-force free, building of wrinkles, tool

Commercial Opportunities

With FlexBend metals can be bent into complex shapes and variable cross-sections. FlexBend is also especially suitable for the manufacture of lightweight design structures consisting of fiber-reinforced plastics which are normally formed in molten state.

Competitive Advantages

  • Transverse-force free
  • No cross section deformation
  • No buckling or cracking
  • No formation of wrinkles
  • Suitable for metals and plastics
  • One tool for all profiles
  • One tool for all materials

Current Status

A German patent application for this invention has been filed at the end of 2016. A first prototype and experimental data on the invention are available. On behalf of the TU Dortmund, PROvendis is seeking a licensee for the new technology.

Relevant Publications

C. Löbbe und G. Grzancic: „FlexBend – Entwicklung einer Technologie zum querkraftfreien Profilbiegen durch flexible Werkzeugformen, 6. Dortmunder Kolloquium zum Rohr und Profilbiegen, 02. - 03.11.2016.

Institute of Forming Technology and Lightweight Components (IUL), Activity Report 2016, TU Dortmund, 30.03.2017,


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