Process forces

Straightening forces and tensile forces are the process forces of relevance during straightening. Straightening forces are understood to be the forces of reaction arising at the interface between the straightening roll and the product to be straightened and owed to the bending moments existing in the process material during forming. Straightening forces act in various directions and magnitudes according to the geometrical boundary conditions. Of the many proposals for calculating the straightening forces (Zeilkow, Geleji and others), the approach proposed by Guericke has proven expedient in practice. As his central instrument Guericke uses the bending moment / curvature hysteresis, which incorporates all the relevant factors affecting the straightening process. The straightening forces correlate with the tensile forces which, affected by the boundary conditions, arise as forward tensile force or pull-off force and reverse tensile force.

The work of plastic deformation performed in the specific case has to be determined in order to calculate the forward tensile force or pull-off force needed to transport a process material relative to the straightening system.

If further technological operations are positioned upstream and/or downstream from the straightening process, the tensile force fractions during the individual operations have to be taken into account when determining the total pull-off force. It is an advantage to ensure as constant a tensile force as possible in the direct vicinity of the processing in order to achieve a final product of high quality on a processing line. This can be promoted by using a decoil-straightener.