Modeling and simulation of web-tension mechanism in a filling machine

Abstract: When carton packages are formed in a filling machine, there have to be a certain tension in the material package to keep it stretched, however not so much that the material is damaged. In the Tetra Pak A1 filling machine this is achieved through a \emph{web tension-mechanism} consisting of a number of rollers and a pneumatic cylinder. The aim of the master thesis is to get a simulation model for this web-tension mechanism, with the end goal of being able to predict how the mechanism will work under different pneumatic pressures and with different package shapes. To have the needed parameters for the simulation, the pneumatic cylinder was tested in a load testing equipment, and the parameters were extracted from test results. The simulation model was split in two parts, with one being a Dymola logical model of the pneumatic subsystem (consisting of the cylinder, a regulator and a connecting tube). This model was built using the Modelon library package \texttt{Pneumatics}. The other part was a Finite Element model of the rollers and the package material, which was done in Abaqus Explicit. The two models were cosimulated and the total force at the end of the moving web was logged. The simulated force variations were compared to variations that had been measured during actual production runs with the machine that was modelled. The ultimate goal of the project is to have a small rheological Abaqus model containing dynamics of all parts, including a simplified version of the pneumatics. This could then be connected to the models of other parts of the machine that have earlier been modelled.