A web is continuous, flexible materials such as paper, plastic film, metal foil, textiles, etc Web wrinkle is a problem which plagues the process industries Most webs are very thin and prone to buckle or wrinkle The effects of wrinkling can range from compromised product quality to down time of a processing operation, leading to less profitability in the manufacturing operation The web wrinkles which will be treated in this paper are those that can be affected by roller misalignment and friction characteristics between web and roller In this paper, observation method is presented for paper-web wrinkling and the prediction model of wrinkling is proposed with experimental verifications

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Prediction model of paper-web wrinkling and some numerical calculation examples with experimental verifications

Roll-to-roll systems handling web material such as papers, polymers, textiles or metals are very common in the industry Web handling systems are recently used to produce new technologies such as printed semi-conductors, thin solar panels, printed electronics, etc In web handling systems, one of the main objectives is to reach a good accuracy of web tension and web speed For the tuning of machineries, one-dimensional models are commonly used and they do not take into account several three-dimensional mechanical phenomena initiated by lateral components of the elastic web dynamics It is necessary to develop new models in order to optimize roll-to-roll systems This paper presents for the first time robust control applied to web dynamics modeled in 3D Moreover, for the first time, 1D and 3D modeled roll-to-roll systems (including controllers) are compared

Robust control in industrial roll-to-roll systems: New approaches using finite element modeling of the web

Published roller alignment guidelines are almost nonexistent in the web industries and are largely confined to internal publications of very few machine builders. Furthermore, those standards were based on what these builders could do rather than necessarily what they should do; sometimes resulting in excessive maintenance costs. Worse yet, almost all builders are silent on the subject of alignment; at times causing excessive waste and delay due to problems such as mis-registration, web breaks and wrinkling. What this article seeks to do is to define maximum allowable misalignment tolerances based on web handling models and principles.

Roller Alignment - Standards

Roll-to-roll systems handling web material such as papers, polymers, textiles or metals are very common in the industry. Web handling systems are recently used to produce new technologies such as printed semi-conductors, thin solar panels, printed electronics, etc. In web handling systems, one of the main objectives is to reach a good accuracy of web tension and web speed. For the tuning of machineries, one-dimensional models are commonly used and they do not take into account several three-dimensional mechanical phenomena initiated by lateral components of the elastic web dynamics. It is necessary to develop new models in order to optimize roll-to-roll systems. This paper presents for the first time robust control applied to web dynamics modeled in 3D, including web tension decoupling between consecutive web spans.

Robust industrial control with optimized decoupling in roll-to-roll systems: New approaches using finite element modeling of the Web

Micro- and nanofabrication on polymer substrate is integral to the development of flexible electronic devices, including touch screens, transparent conductive electrodes, organic photovoltaics, batteries, and wearable devices. The demand for flexible and wearable devices has spurred interest in large-area, high-throughput production methods. Roll-to-roll (R2R) nanoimprint lithography (NIL) is a promising technique for producing nano-scale patterns rapidly and continuously. However, bending in a large-scale R2R system can result in non-uniform force distribution during the imprinting process, which reduces pattern quality. This study investigates the effects of R2R imprinting module geometry parameters on force distribution via simulation, using grey relational analysis to identify optimal parameter levels and ANOVA to determine the percentage of each parameter contribution. The study also investigates the length and force ratio on a backup roller used for bending compensation. The simulation results and the artificial neural network (ANN) model enable the prediction of nip pressure and force distribution non-uniformity along the roller, allowing the selection of the optimal roller geometry and force ratio for minimal non-uniformity on a specific R2R system. An experiment was conducted to validate the simulation results and ANN model.

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Multi-Geometry Parameters Optimization of Large-Area Roll-to-Roll Nanoimprint Module Using Grey Relational Analysis and Artificial Neural Network

In modelling web handling system as controlled dynamic system the model of the web selected can effect system behavior. Webs are membranes capable of resisting tensile stresses but incapable of resisting compressive stresses due to buckling or `wrinkling'. This allows at least two unique web models tobe formed. The first model assumes that the web line tension is large enough that bending of a web, due to a controller or roll misalignment, does not produce compressive stresses. Thus the web can be modeled as a beam in bending. The second model assumes that the web has wrinkled and now must be modeled as a series of ribbons between wrinkles. Results of an experimental investigation are presented to help determine which web model is valid such that an appropriate control strategy can be implemented.

L. S. Gehlbach

Papers

Web Wrinkling Effects on Web Modeling