Simulating Dynamic Tension Effects From an Out-of-Round Unwind Roll

Web handling systems maintain a certain amount of tension in the web and a process speed. Non-circular rolls of material are not uncommon in the real world arising from storing the rolls or imprecise control of parameters. Non-circular rolls at the beginning of a web handling system cause tension spikes in the web as they are unwound. Simulating the tension effects of the non-circular unwind roll is the aim of this paper. A review of numerical models, called primitive elements, for web handling systems is included. The parameters required to describe a web handling system are reviewed. A primitive element for modeling a non-circular roll is introduced. The web handling system model, which uses linear and nonlinear elements in simulation, is compared with experimentally measured data.