Dynamic on-line sensing of sheet modulus of elasticity

This paper proposes and evaluates a methodology for robust, on-line estimation of the modulus of elasticity of an elastic strip transported through a multi-span system. The estimation algorithm is based on a previously developed robust sensorless sheet tension estimation, and the computation of speed draws using 1024-pulse encoders operating in 4x mode. The evaluation of the proposed algorithm was performed in the dry end of a LWC (lightweight coated) paper machine. Results confirm the robustness of the on-line estimation and its ability of detecting rapid changes that may occur in the modulus of elasticity. The proposed algorithm will open new and interesting options for further improvements of the paper-making process.