Modeling of Temperature Distribution in a Moving Web Transported Over a Heat Transfer Roller

A model for thermal behavior of a moving web transported over a heat transfer roller is developed in this paper. Heat transfer rollers are employed widely in roll-to-roll systems that contain processes such as printing, coating, lamination, etc., which require heating/cooling of the moving web material. The web is either cooled or heated by wrapping the moving web around the rotating heat transfer roller. The goal in such roll-to-roll processes is to transport the web over heating/cooling rollers at a specified web tension and transport velocity, and web tension in the material is affected by mechanical strain and thermal strain in the web. Temperature distribution in the moving web is needed to determine thermal strain. A general one-dimensional heat transfer model is used for describing the heat transfer process in the moving web material and the outer shell of the heat transfer roller. Based on this model, the temperature distribution in the web in the region of wrap on the heat transfer roller and in the free span are obtained by considering appropriate boundary conditions and initial conditions. Model simulations are conducted to determine the temperature profile in the web wrapped on a heat transfer roller; simulations are also conducted for a portion of an embossing line which contains heat transfer rollers. The model simulation results are compared with a limited amount of measured data available on a production embossing line.