Hyde, G.G.HydeUlrich, R.R.Ulrich2022-03-082022-03-081997https://publica.fraunhofer.de/handle/publica/303575WO 9203580 A UPAB: 19931006 In heat treating cylindrical corrugating rolls which are used in the mfr. of corrugated paperboard, a Gaussian output beam from a CO2 laser is reconfigured to a beam with a substantially homogeneous power density. The homogeneous beam is focused onto a flute of the corrugating roll. The roll is moved in relation to the beam in order to harden the flute of the roll. The Gaussian beam is reconfigured to a top hat beam forming a square spot, by an integrator lens. The roll is coated with a light-absorbing coating such as graphite prior to positioning and traversing the beam. The flute is heat treated to a depth of approximately 0.06-0.09 inches to a hardness of 61-66 R. ADVANTAGE - The entire flutes including the tips roots and flanks are heat treated without overheating and otherwise distorting the roll. 1/5de608667621671patent1990-5709361990-575928