R. Keßler
S. Langbein
C. Pelshenke
M. Hudovernik
P. Dültgen
R. Lahdo
C. Hennigs
M. Hustedt
S. Nothdurft
J. Hermsdorf
S. Kaierle

Laser-based tensioning of circular saw blades

Proc. Tooling 2019 Conference
Type: Zeitschriftenaufsatz (non-reviewed)
Disc-shaped tools represent a very important aspect in the processing of solid materials such as concrete, natural stone, wood, composites, food products, paper etc. The cutting efficiency of such tools strongly depends on their diameter and material thickness as well as on the intensity of axial vibrations which occur inside the material when applied to working conditions. A non-optimal design does not only decrease the working efficiency, but also reduces the life span of the tools due to high wear. Thinner saw blades with larger radii cut out less material, but allow deeper cuts. However, very thin saws blades with larger diameters vibrate more intensely compared to thicker ones. Commonly, manufacturers apply additional technological processes, such as annual roll-tensioning, to decrement these effects. In this way, the stiffness of saw blades can be adjusted individually according to their purpose and targeted operating conditions. The distribution of residual stresses in tangential and radial directions plays a key role in increasing the stiffness. Residual stresses tend to shift natural frequencies so that no resonance occurs during full working conditions. To achieve the highest stiffening effect, a concentration of tangential tensile residual stresses in the outer area of the circular saw blade is required. Thermal tensioning processes based on the use of laser technology can be a good alternative to achieve the same effects by inducing tensile residual stresses. This effect is also beneficial during the cutting process for counteracting the developing heat and the associated thermal expansion. The effects of thermal tensioning processes using laser radiation are investigated in this paper