The length of web in a wound roll is one mark of roll quality. The available web length in a roll is a concern for many who process webs and those who convert webs. There are algorithms that estimate the length of web and layers in a wound roll based on simple geometry and inputs of inside and outside radius and web thickness. If webs were infinitely stiff in the machine and out-of-plane directions such calculations could be accurate but this is not the case. Webs deform as the result of winder operating conditions such as winding tension and the contact pressures and stresses due to winding. Length calculations based on geometry will err as a result of web deformation in the length and radial directions. Webs are generally subject to tension during transport through process machines, the apparent deformed web length will vary with transport tension. The mission of this paper is to describe means by which the available deformed web length and the number of layers in a wound roll can be accurately predicted. The accuracy of the predictions will be verified by winding trials in the laboratory. The winding trials will demonstrate the levels of accuracy that can be realized on laboratory and production machines.
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Mechanics of Cambered Web Belts on Aligned Rollers
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 the focus of the current work. Dynamic simulation (Abaqus/Standard) has been used to better understand the response of cambered webs under tension that has been witnessed in tests.
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- Award ID(s):
- 1635636
- NSF-PAR ID:
- 10110752
- Date Published:
- Journal Name:
- Proceedings of the Fifteenth International Conference on Web Handling
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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