The lateral deformations of webs in roll-to-roll (R2R) process machines can affect the quality of the manufacturing process. Webs can enter a cylindrical roller normally if the forces required to sustain normal entry and do not exceed the available friction forces. Webs with simple non-uniform length variation across their width (camber) will steer toward the long side, affecting the steady state lateral deformation and hence registration. Most previous studies have focused on tests and modeling a cambered web span in a free span between two rollers. Often these studies assume some displacement and slope boundary conditions are known and seek the remaining condition(s) that would dictate the steady state lateral deformation of the cambered web in the free span. In many spans in a process machine there may be no known boundary conditions and no steady state deformation of the cambered web. The web may travel toward the long side continually from one web span until the next until a web guide attempts to return the web to an acceptable lateral location in the process machine. The simplest case of multiple span cambered web lateral behavior is that of a cambered web belt transiting two aligned rollers which is themore »
Impact of Large Deformations of Webs Transiting Rollers
Webs are subjected to large out-of-plane deformations when transiting rollers in process machinery. Webs are often treated as membranes in analysis but become subject to significant bending strains when transiting rollers. Anticlastic bending of thick plates is a known phenomenon. The anticlastic effect is often ignored for webs which are thin. The objective of this paper is to demonstrate that the large bending deformations webs are subjected to on rollers influence the internal membrane stresses and deformations in the web. The results will show that the concept of normal entry of a web to a roller has complexity that has previously not been considered. It will be demonstrated that a cross direction tensile membrane stress results from the large deformations that acts to stabilize the web and inhibit wrinkle formation.
- Award ID(s):
- Publication Date:
- NSF-PAR ID:
- Journal Name:
- Proceedings of Fourteenth International Conference on Web Handling
- Sponsoring Org:
- National Science Foundation
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