Continuous retention monitoring system as a tool for the optimization of wet end operation

In this paper a continuous retention monitoring system based on low-consistency sensors is introduced. This measurement system was applied in testing retention agents and optimizing their dosages at a papermill producing several grades of wood-containing and wood-free printing papers. The effects of two different retention aids, varying beating degrees, and different alum concentrations on retention are illustrated, and the relationship between ash retention and first-pass retention of total solids is discussed. The impacts of these two retention agents on paper properties and process variables are also compared.