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.

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.

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.

A Nonlinear Tension Control Scheme for Web Transport Through Heating Processes

2015 ◽  
Author(s):  
Youwei Lu ◽  
Prabhakar R. Pagilla
Keyword(s):  
Heat Transfer ◽  
Thermal Effects ◽  
Tension Control ◽  
Web Based ◽  
Transfer Processes ◽  
Roll To Roll ◽  
Flexible Material ◽  
Control Scheme ◽  
The Web ◽  
Web Tension

In this paper we develop a model-based nonlinear tension control scheme for transport of flexible materials (webs) through heating processes. Heat transfer processes are widely employed in Roll-to-Roll (R2R) process machines that are used to perform processing operations on a moving web on rollers. Heat transfer processes induce thermal expansion/contraction of the flexible material during transport. Because web strain and elastic modulus are functions of temperature distribution in the web, web tension resulting from elastic strain is affected by heating/cooling of the web. Based on a web tension governing equation that includes both elastic and thermal effects, a nonlinear tension control scheme is developed for control of tension in each tension zone of an R2R system. The control scheme is implemented on an R2R experimental platform containing two heat transfer rollers, one for heating the web and one for subsequently cooling the web prior to winding of the web. Experimental results are presented and discussed.

scholarly journals Modeling and Analysis of Web Span Tension Dynamics Considering Thermal and Viscoelastic Effects in Roll-to-Roll Manufacturing

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Kadhim A. Jabbar ◽  
Prabhakar R. Pagilla
Keyword(s):  
Temperature Change ◽  
Governing Equation ◽  
Thermal Strain ◽  
Measured Data ◽  
Material Behavior ◽  
Closed Form Expression ◽  
Roll To Roll ◽  
Viscoelastic Effects ◽  
The Web ◽  
Web Tension

A governing equation for web tension in a span considering thermal and viscoelastic effects is developed in this paper. The governing equation includes thermal strain induced by web temperature change and assumes viscoelastic material behavior. A closed-form expression for temperature distribution in the moving web is derived, which is utilized to obtain thermal strain. A model for web tension in a multispan roll-to-roll system can be developed using this governing equation. To evaluate the governing equation, measured data from an industrial web process line are compared with data from model simulations. Since the viscoelastic behavior of web materials is affected by the web temperature change, elevated temperature creep, and stress-relaxation experiments are conducted to determine the temperature-dependent viscoelastic parameters of the utilized viscoelastic model. Comparisons of the measured data with model simulation data are presented and discussed. An analysis of the web tension disturbance propagation behavior is also provided to compare transport behavior of elastic and viscoelastic materials.

Advanced Motion Control Design for Longitudinal Web Dynamics in Roll-to-Roll Systems: Velocity or Position Control?

2013 ◽  
Author(s):  
Y. Martz ◽  
J. Frechard ◽  
D. Knittel
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Tension Control ◽  
Web Handling ◽  
Reference Tracking ◽  
External Loop ◽  
Roll To Roll ◽  
Processing Line ◽  
The Web ◽  
Web Tension

Roll-to-Roll systems handling web material such as papers, polymers, textiles or metals are very common in the industry. One of the main objectives in web handling plant is to reach an expected web speed while maintaining the web tension within an acceptable range around the tension reference in the entire processing line. In the recent years, several works have focused on the topic of web tension control using H∞ approaches. In the traditional way, each motor driven roller is controlled in speed and the web tension control is ensured by an external loop. This paper proposes to compare, for the first time, the traditional control strategy with a control strategy including position control rather than speed control. In fact, position control is commonly used in printing industry. The comparison will be ensured in frequency and time domain and take into account the reference tracking performances and the robustness to web elasticity variations.

Register control of roll-to-roll gravure-offset printing equipment considering time difference between measurement and actuation

2012 ◽  
Vol 226 (11) ◽  
pp. 2726-2738 ◽  
Author(s):  
Chung Hwan Kim ◽  
Ha-Il You ◽  
Seung-Hyun Lee
Keyword(s):  
Measurement System ◽  
Position Control ◽  
Printed Electronics ◽  
Control Method ◽  
Axial Direction ◽  
Time Difference ◽  
Offset Printing ◽  
Drying Time ◽  
Roll To Roll ◽  
The Web

The manufacture of printed electronics by roll-to-roll printing machine requires more accurate register performance than conventional media printing technology. Moreover, high drying temperature and long drying time to sinter the inks can induce the substantial changes in the length of the substrate and consequently register errors. Among the roll-to-roll printing methods, the gravure one, despite its relatively fast productivity and fine-line printing capacity, has difficulty in achieving the required register specifications for printed electronics because of the dependence of the register control on web dynamics. This study proposes a roll-to-roll gravure-offset printing equipment, including the register measurement system designed to enhance register performance and the related register control method for the application of printed electronics. Each cylinder constituting the printing unit is driven independently by an individual servomotor. Moreover, the printing patterns of the plate cylinder can move in the axial direction by position control, as well as in the web transport direction by a phase shift of the plate cylinder, without affecting the dynamics of the web. The time difference between the measurement and the actual control action is considered and modeled. The register measurement system, including selections of sensors and marks is also proposed to consider the effect of the time difference. The simulation results and the experiments of the register control are shown to verify the effect of the time difference on the control performances. It is found that a proper estimation of time difference should be obtained in order to guarantee more accurate and stable control performances.

Category-Based Interfaces for Mobile Search

2015 ◽  
pp. 75-104
Author(s):  
Tomi Heimonen
Keyword(s):  
User Study ◽  
Information Access ◽  
Future Research ◽  
Information Need ◽  
Research Directions ◽  
Search Results ◽  
Future Research Directions ◽  
Mobile Context ◽  
The Web

One of the challenges with designing effective mobile search interfaces is how to present and explore the search results. Category-based result organization and presentation techniques have been suggested in literature as a complement to the traditional ranked result list. In the mobile context categories can facilitate information access by providing an overview of the result set, by reducing the need for keyword entry and by providing means to filter the results. This chapter includes a review of recent research on category-based interfaces for mobile search. The chapter also addresses the challenges of evaluating mobile search in situ and presents a longitudinal user study that investigated how a mobile clustering interface is used to search the Web. Results from the study show that category-based interaction can be situationally useful, for example when users have problems describing their information need or wish to retrieve a subset of results. In summary, the chapter proposes future research directions for category-based mobile search interfaces.

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.

Modeling of Temperature Distribution in Moving Webs in Roll-to-Roll Manufacturing

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Youwei Lu ◽  
Prabhakar R. Pagilla
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Thermal Strain ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Transfer Model ◽  
Roll To Roll ◽  
Flexible Material ◽  
Process Line ◽  
The Web

A heat transfer model that can predict the temperature distribution in moving flexible composite materials (webs) for various heating/cooling conditions is developed in this paper. Heat transfer processes are widely employed in roll-to-roll (R2R) machines that are used to perform processing operations, such as printing, coating, embossing, and lamination, on a moving flexible material. The goal is to efficiently transport the webs over heating/cooling rollers and ovens within such processes. One of the key controlled variables in R2R transport is web tension. When webs are heated or cooled during transport, the temperature distribution in the web causes changes in the mechanical and physical material properties and induces thermal strain. Tension behavior is affected by these changes and thermal strain. To determine thermal strain and material property changes, one requires the distribution of temperature in moving webs. A multilayer heat transfer model for composite webs is developed in this paper. Based on this model, temperature distribution in the moving web is obtained for the web transported on a heat transfer roller and in a web span between two adjacent rollers. Boundary conditions that reflect many types of heating/cooling of webs are considered and discussed. Thermal contact resistance between the moving web and heat transfer roller surfaces is considered in the derivation of the heat transfer model. Model simulations are conducted for a section of a production R2R coating and fusion process line, and temperature data from these simulations are compared with measured data obtained at key locations within the process line. In addition to determining thermal strain in moving webs, the model is valuable in the design of heating/cooling sources required to obtain a certain desired temperature at a specific location within the process line. Further, the model can be used in determining temperature dependent parameters and the selection of operating conditions such as web speed.

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