Reading a roll
Abstract
Web or winder defects often leave a visible record of themselves in the wound roll that can be read much like the rings of a tree. Varying strains in each layer as it is wound will cause changes in geometry that can be observed visually or with simple tools. These cylindricity deviations are a fingerprint of the cause of the defect. This paper shows how to read a roll's history by diametral variations across its width, by radial variances around the periphery, and by variations in width or CD position. Additionally, the winding mechanics that produced the cylindricity deviations will be discussed. Defects covered include corrugations, dishing, ridges, starring, telescoping, and many others.
Citation
Roisum, D. R. (1997, June). Reading a roll. Paper presented at the Fourth International Conference on Web Handling (IWEB), Stillwater, OK.