Patent ID: 6588332
Filing Date: 2003-07-08
Classification: D21G

Abstract:
A group of rolls for processing material webs, the group of rolls including at least two equally flexible rolls comprising:a reference roll comprising a reference roll body, at least one bolted-on journal, and a central bore; and a second roll comprising a second roll body, at least one bolted-on journal, and a central bore, wherein: the group of rolls are mounted in rolling-contact bearings in the region of the journals, the reference roll comprises a first cast iron material and the second roll comprises a second cast iron material, each of the reference roll body and the second roll body has a diameter that is greater than 500 millimeters, each of the reference roll and the second roll has a ratio between a web length and a diameter that is greater than seven, the central bore of the reference roll has a diameter such that the wall thickness of the reference roll is between approximately 100 millimeters and 300 millimeters, a first vertical sag fref is defined as comprising a vertical deflection of an axis of the reference roll under the influence of gravity, wherein the first vertical sag is between 0.1 millimeters and 0.2 millimeters per meter of the web length when the reference roll body is supported in the rolling-contact bearings, a second vertical sag f is defined as comprising a vertical deflection of an axis of the second roll, and the central bore of the second roll has a diameter determined on the basis of a dead weight of the second roll in the region of the web length and a mean modulus of elasticity of the second roll such that the sag f of the second roll is approximately equal to the sag fref of the reference roll.