Shape determines the quality
During cold rolling, the shape of the strips is today one of the most important distinguishing features when assessing strip quality. With different measuring rolls Vollmer covers the whole spectrum of strip shape measurement technology.
Vollmer uses the results from all the systems for the optional Automatic Flatness Control (AFC).
The BFI shapemeter roll that we produce under licence from the VDEh-Betriebsforschungsinstitut (BFI) and the segment roll for stretch bend levellers developed by us cover the whole spectrum of tactile strip shape measurement technology.
Strip shape control
Our detailed know-how of the rolling process makes us one of the few manufacturers to also offer complete control systems for the strip shape – from the sensor through to the control of the adjusting elements.
Excursion: Flat or level?
Unflatness results from tension in the strip which varies over the strip width. It expresses itself among other things by waviness at the strip edges or in the middle of the strip. The tension is relieved during slitting – and the individual strips are different in length.
The flatness is defined in I-units One I-unit corresponds to a difference in length of 10 µm per metre of strip length.
The levelness describes the topography of the strip surface, i.e. the deviations in height observed when the strip lies on a level surface.
The measuring rollers and the VIP08 optical system from Vollmer measure the flatness.