摘要 |
In a group of rolls for a calender for processing material webs, comprising at least two rolls each having a roll body made of a cast or forged iron material, at least one of the roll bodies consists of chilled cast iron or shell-chilled cast iron. One or more rolls may have a cover of a resilient material, such as a polymeric plastic. Although it is possible for the outer diameters of the rolls to differ, the sag of the rolls when they are supported only in their rolling-contact bearings is substantially equal. In order to produce appropriate rolls, following the essential machining steps of the roll bodies, that is to say, for example, following casting, following preliminary turning, following preliminary boring and, if appropriate, following the introduction of peripheral bores, the actual mean modulus of elasticity of the entire roll body is measured and, as a function of this, in particular the inner diameters of the central bores are produced. In addition, methods for influencing the sag of the rolls in a deliberate way, by selecting appropriate materials, the relationships of material structures in the roll body or by means of the deliberate introduction of ballast into the central bore or else into separate peripheral bores in the roll bodies, are described.
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