Patent ID: 7169258

Claim:
A process of treating a fiber stock suspension to produce at least one of paper and cardboard having filled fibers therein, said process comprising the steps of: providing the fiber stock suspension, with a moistened fiber material having fiber surfaces, said stock suspension having a stock pH associated therewith, said stock pH being set in an approximate range of 10 to 13; adding at least one additive to the fiber suspension, including at least CaCO 3 ; treating the fiber suspension and the at least one additive together in a fluffer operated under fiber stock fluffing conditions; separating the fiber material within said fluffer so as to increase a specific surface thereof, thereby optimizing accessibility of educts to the fiber surfaces; filling fibers within the fiber stock suspension with said additive to form filled fibers; and passing the treated fiber stock suspension to a paper machine and forming the at least one of paper and cardboard with the treated fiber stock suspension.