A Friction Model for Laminator Nips

Abstract: The main objective for the thesis project is to find a suitable mathematical model of the velocity dependent friction force that arises between the nip roller and the carton material in the laminator at slip, in order to enable realistic simulations of the nip in the laminator. Theoretically, the LuGre model is found to contain the necessary physical properties for the actual situation. Experiments are conducted measuring friction between a rubber sample and carton samples in order to find an expansion and validation of the model. The model is found to produce a satisfactory low-magnitude residual in relation to the experiments for the range that varies with velocity. During the low velocities high-amplitude friction induced oscillations appear making the measurements highly inaccurate. It is known, however, that the slip will never reach these low velocities so this source of error is disregarded. Also, the measurement instrument is found not to be entirely ideal for this project. An instrument that can continuously change the velocity would be better. This model is good for most of the nip cases. However, further investigations are needed for the boundary effects that arise due to the cylindrical shape of the rollers and also a way to identify the dynamical parameters and thus expand from a steady-state model to a dynamical model.