Mass-balance based soft sensor for monitoring ash content at two-ply paperboard manufacturing

Continuous and robust measurements are needed for the high end-product quality and efficient and eco-friendly process in paperboard manufacturing. As the online measurements enable the optimization of the manufacturing process making it more cost effective and environmentally friendly, these measurements must be validated carefully and continuously. This paper presents the development of a mass-balance based soft sensor for online estimation of a two-ply paperboard ash content. The developed soft sensor considers the basis weight, moisture and fiber measurements to derive the ash content of the paperboard at the reel. The development of the soft sensor was success (Mean Absolute Percentage Error was 11.80) and during the long-term simulation with measured data, this robust online estimator showed the level and changes in ash content accurately, enabling also the continuous validation of the hardware sensor.