Modeling of Web Slip on a Roller and Its Effect on Web Tension Dynamics

2005 ◽  
Author(s):  
Ramamurthy V. Dwivedula ◽  
Prabhakar R. Pagilla
Keyword(s):  
Numerical Computation ◽  
Dynamic Models ◽  
Simple Approach ◽  
Roller Surface ◽  
Perfect Adhesion ◽  
The Web ◽  
Web Tension

This paper considers the effect of web slip over the rollers on the span tension dynamics. In classical development of the web span tension dynamics, it is assumed that there is strict adhesion between the web and the surface of the roller and thus, there is no slip-page between the web and the roller. As a result of this assumption, effect of tension disturbances in downstream spans on the upstream span tension is precluded. However, in practice, perfect adhesion between the web and roller surface is seldom achieved and tension disturbances propagate upstream also. Though web span tension dynamic models that include slippage between web and roller are proposed, these models rely to a great extent on numerical computation of slip arc angles and are prohibitively complex to be of practical use. This paper proposes an alternative, simple approach for developing web span tension dynamics to include the effect of web slip.

Advanced Optimization of Industrial Large-Scale Roll-to-Roll Systems Under Parametric Uncertainties

2012 ◽  
Author(s):  
J. Frechard ◽  
D. Knittel
Keyword(s):  
Young’S Modulus ◽  
Large Scale ◽  
Young's Modulus ◽  
Robust Design Optimization ◽  
Parametric Uncertainties ◽  
Optimization Approach ◽  
Roll To Roll ◽  
Polymer Metal ◽  
The Web ◽  
Web Tension

In industrial plants some parameters can not be evaluated properly or they are varying with time. These parametric uncertainties has to be taken into account during the design process of industrial systems. In this work, the developped optimization approach is applied on an industrial roll-to-roll sytem. Such systems are commonly used to handle materials as polymer, metal, paper and textile. The key challenge is to move the web at the expected speed while maintaining the web tension in an acceptable range around its reference. Moreover, the Young’s modulus of the web is difficult to evaluate and it is varying with time due to temperature and moisture variations. This paper deals with the web tension controller synthesis on a large-scale roll-to-roll system with uncertain Young’s modulus. To synthesize web tension controllers, an H∞ approach is applied and adapted to the system with parametric uncertainties using multi-objective robust design optimization.

Longitudinal and Out-of-Plane Stiffness of a Web in an Air-Flotation Oven

1999 ◽  
Author(s):  
Young B. Chang ◽  
Ronald P. Swanson ◽  
Peter M. Moretti
Keyword(s):  
Analytical Model ◽  
Experimental Results ◽  
Photographic Film ◽  
Longitudinal Stiffness ◽  
Out Of Plane ◽  
Air Cushion ◽  
Air Flotation ◽  
Low Tension ◽  
The Web ◽  
Web Tension

Abstract Air-flotation ovens are used for non-contact drying of coated web materials such as photographic film, magnetic media, and paper. In a typical air-flotation oven, the air bars are arranged in such a way that the path of web is nearly sinusoidal. When web tension fluctuates, the distance between the web and the air bars also changes. This phenomenon affects the longitudinal dynamics and tension control of an air-floated web. In some cases, tension fluctuations can cause the web to touch the air bars, resulting in damage to the coating and the web. This paper discusses an analytical model of the extensional resiliency of an air-floated web. The analysis shows that at low tension the longitudinal stiffness of an air-floated web is small, being dominated by the air cushion effects. At higher web tension, however, the effects of material deformation become more important than the air cushion effects. The analysis is compared with the experimental results obtained in a pilot air-flotation oven. The analytical and experimental results show the same trends, though the analytical model tends to underpredict the longitudinal stiffness of air-supported webs.

Bahnzugkraftregelung in der Batteriezellfertigung*/Web tension control in battery cell production

2018 ◽  
Vol 108 (07-08) ◽  
pp. 519-524
Author(s):  
H. Weinmann ◽  
F. Lang ◽  
J. Hofmann ◽  
J. Fleischer
Keyword(s):  
Dimensional Accuracy ◽  
Tension Control ◽  
Selection Function ◽  
Battery Cell ◽  
Cell Production ◽  
Material Parameters ◽  
Single Sheet ◽  
The Web ◽  
Web Tension

Viele Maschinen- und Materialparameter sind für die Qualität eines Elektroden-Einzelblattes verantwortlich. Relevant für Vereinzelung und Stapelbildung ist etwa die Bahnzugkraft, mit der die Elektrodenbahn während des Stanzvorgangs beaufschlagt wird. Diese wurde in der Versuchsanlage des wbk Institut für Produktionstechnik regelbar ausgeführt, um Zusammenhänge bei der Einzelblattstapelbildung zu untersuchen. Dieser Artikel stellt Auswahl und Funktion sowie die Integration der Lösung in die Versuchsanlage und die Auswirkung verschiedener Bahnzugkräfte auf die Maßhaltigkeit der gestanzten Einzelblätter vor.   The quality of an electrode single-sheet is affected by a multitude of machine and material parameters, such as the web tension force for separating and stacking applied to the electrode web during die cutting. As an adjustable force it was analyzed in a demonstrator at the wbk Institute of Production Science to identify interdependencies during single-sheet-stacking. This article presents the selection, function and integration of the solution into a demonstrator and how different web tension forces affect the dimensional accuracy of die-cut sheets.

scholarly journals Roll-to-roll infrared and hot-air sintering of gravure-printed Ag layer based on in situ tension measuring and analysis

2016 ◽  
Vol 4 (38) ◽  
pp. 8884-8888 ◽  
Author(s):  
Janghoon Park ◽  
Hyi Jae Kang ◽  
Hyogeun Gil ◽  
Kee-Hyun Shin ◽  
Hyunkyoo Kang
Keyword(s):  
Hot Air ◽  
Roll To Roll ◽  
The Web ◽  
Web Tension

The sintering energy was quantified and evaluated based on theoretical and experimental calculations. Moreover, the effect of the sintering energy on the web tension was simultaneously considered.

Improvement of Web Spacing and Friction Characteristics by Two Types of Stationary Guides

2000 ◽  
Vol 123 (3) ◽  
pp. 509-516 ◽  
Author(s):  
Hiromu Hashimoto ◽  
Haruyasu Nakagawa
Keyword(s):  
Hydrostatic Pressure ◽  
Friction Coefficient ◽  
Hydrodynamic Pressure ◽  
Back Surface ◽  
Gaussian Distributions ◽  
Reflected Light ◽  
Experimental Apparatus ◽  
Entrained Air ◽  
The Web ◽  
Web Tension

In this paper, two types of stationary guides are presented to improve the web spacing characteristics; hybrid hollow porous guide for maintaining the sufficient web spacing and grooved guide for removing the entrained air. In the hybrid hollow porous guide, the pressurized air is added to the lubrication air flow between web and guide from inside the guide. Then, the web spacing characteristics are improved by the hybrid effects of hydrodynamic pressure due to web movements and hydrostatic pressure due to pressurized added air through the guide. The relations between web spacing and web velocity are measured under various supply pressures. Moreover, the relations between web spacing and web tension are examined. The contactless optical sensor, which can measure the variation of the quantities of reflected light from the back surface of web according to the variation of web spacing, is used to obtain the web spacing under various conditions. In the grooved guide, the method for the estimation of web spacing by using the concept of equivalent spacing between web and guide is presented, and the web spacing is measured by the same experimental apparatus used in the case of hollow porous guide. From the calculated and measured results obtained, the effectiveness of two types of guides on the web spacing is clarified. Finally, based on the assumptions of Gaussian distributions of asperities, the simple relations to predict the friction coefficient between web and guide surfaces are formulated, and the variation of friction coefficient with velocity is shown for various values of web tension.

System for Automatic Web Guiding for Roll-to-Roll Machine Working in a Start-Stop Mode

2014 ◽  
Vol 223 ◽  
pp. 374-382
Author(s):  
Mirosław Neska ◽  
Andrzej Majcher
Keyword(s):  
Material Processing ◽  
Control System ◽  
Processing Machine ◽  
Processing Machinery ◽  
Roll To Roll ◽  
Transport Velocity ◽  
The Web ◽  
Selection Of ◽  
Web Tension ◽  
Hardware Structure

Web guiding used in roll-to-roll material processing machinery is connected with a number of issues including the maintenance of the web tension, the precision of the lateral web displacement, the accuracy of transport positioning of the web, and the selection of web transport velocity. The article presents the precision of the lateral web displacement issue during the start-stop work mode of the web transport. A model of a system for automatic web guiding is shown. The requirements of the lateral web guiding for transporting material over rollers in a processing machine working in a start-stop mode are presented. The control system is discussed, particularly its hardware structure and behaviour. The obtained functionality of the control system enables its application in roll-to-roll material processing machines, working either in the start-stop mode or continuously.

Modeling Web Tension Dynamics Considering Thermal and Viscoelastic Effects: Simulations and Experiments

2014 ◽  
Author(s):  
Kadhim A. Jabbar ◽  
Prabhakar R. Pagilla
Keyword(s):  
Thermal Strain ◽  
Viscoelastic Model ◽  
Model Simulations ◽  
Viscoelastic Parameters ◽  
Viscoelastic Effects ◽  
Processing Line ◽  
Materials Used ◽  
Creep And Stress Relaxation ◽  
The Web ◽  
Web Tension

In this paper, a governing equation for web tension considering thermal and viscoelastic effects in a multi-span system is developed. The thermal effect is included in the web tension dynamics by considering the thermal strain induced by temperature distribution in the web span. The viscoelastic effect is introduced by using a standard linear solid (SLS) model from which a relationship between the applied stress and the resulting strain is obtained. Elevated temperature creep and stress relaxation experiments are conducted on several web materials used in an industrial web processing line to determine the viscoelastic parameters of the utilized viscoelastic model. Model simulations are conducted with the same control systems as those used in an industrial web processing line. Data from model simulations are compared with measured data obtained from the industrial web processing line.

scholarly journals Symposium 20 - PABMB: Teaching biochemistry in a connected world: KEEPING 3D RESOURCES IN THE WEB TO LEARN ON PROTEIN STRUCTURE

2015 ◽  
Vol 13 ◽  
pp. 41
Author(s):  
Raul Herrera ◽  
M. A. Moya-León
Keyword(s):  
Protein Structure ◽  
Undergraduate Students ◽  
Dynamic Models ◽  
Protein Structures ◽  
Practical Experience ◽  
Dimensional Structure ◽  
New Paradigm ◽  
Ligand Interaction ◽  
Motivation For Learning ◽  
The Web

Symposium 20 - PABMB: Teaching biochemistry in a connected world Chair: Miguel Castanho, Universidade de Lisboa, PortugalAbstract:The new paradigm of higher education requires new teaching strategies to meet the learning objectives of biochemistry courses. Teaching biochemistry in the current state of science and society requires a special motivation for learning, especially for students of degrees other than Biochemistry. The traditional way of teaching, based on the teacher-student relationship, mostly unidirectional, does not fulfil the needs imposed in this era. Considering the current situation universities students require new abilities in their training and the use of computers can constitute a place for discovery and research, enabling the experience of new and diverse situations. The design of teaching material for undergraduate students who take biochemistry courses as complementary subject on their careers should be seen as an opportunity to complement theoretical aspects on the current courses. Three different approaches could be used: (I) a description of the basic concepts, like in a book but using dynamics figures. (II) Modelling proteins highlighting key motifs at the three-dimensional structure and residues where inhibitors can be attached. And (III) elaborating active quizzes where students can be driven on their learning. Building knowledge based on practical experience can improve student competences on basic science and the learning process can be complemented in the use of dynamics models. On the other hand, exploring protein structures from the web could give students a better comprehension of residues interaction and non-covalent forces involved in protein-protein or protein-ligand interaction. The use of dynamic models improves the comprehension of protein structure and their special link to amino acids residues or ligands. This work was supported by Anillo ACT1110 project. Key Words: protein structure, 3D source, learning activities.

Governing Equations for Web Tension and Web Velocity in the Presence of Nonideal Rollers

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Carlo Branca ◽  
Prabhakar R. Pagilla ◽  
Karl N. Reid
Keyword(s):  
Exit Point ◽  
Entry And Exit ◽  
Governing Equations ◽  
Periodic Oscillations ◽  
Transport Velocity ◽  
Almost All ◽  
Tension Regulation ◽  
Web Platform ◽  
The Web ◽  
Web Tension

Since rotating machinery is used to transport flexible materials (commonly known as webs) on rollers, it is common to observe periodic oscillations in measured signals such as web tension and web transport velocity. These periodic oscillations are more prevalent in the presence of nonideal elements such as eccentric rollers and out-of-round material rolls. One of the critical needs in efficient transport of webs is to maintain web tension at a prescribed value. Tension regulation affects almost all key processes involved during web transport including printing, registration, lamination, winding, etc. Governing equations for web tension and transport velocity that can accurately predict measured behavior in the presence of nonideal rollers are beneficial in understanding web transport behavior under various dynamic conditions and the design of suitable web tension and speed control systems. The focus of this paper is on modeling the effect of eccentric rollers and out-of-round material rolls on web tension and web transport velocity. The new governing equations for web velocity on an eccentric roller and web tension in spans adjacent to the eccentric roller are presented and discussed; a web span is the free web between two consecutive rollers. To solve these governing equations, the location of the entry and exit point of the web on the eccentric roller as it rotates and the length of the web spans adjacent to the eccentric roller are required; a procedure for obtaining this information is described. To corroborate the models and the developed approach, data from experiments on a large experimental web platform are compared with data from model simulations, and a representative sample of the results are presented and discussed.

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