Application of In-situ CaCO3 Formation Method for Better Utilization of Recycled Fibers (1)

Abstract

ABSTRACT In-situ CaCO 3 formation on recycled wood pulp was studied to improve optical property and filler attach-ment to the fiber furnish in papermaking. We tried to attach calcium oxide (CaO) to the recycled fibers, old newspaper (ONP) in this case, by using selected polymers before in-situ CaCO 3 formation reaction on fibers, and then, CO 2 was injected to the furnish until all the CaO on fiber surfaces was consumed. It was found that the attachment of newly formed CaCO 3 to recycled fibers became stronger by attaching CaO to the fibers before in-situ CaCO 3 formation reaction. It was expected that the polymers used for the attachment of calcium source to the fiber furnishes helped to keep the newly formed CaCO 3 strongly attached to the fiber surface as well as to retain the impurities associated with calcium source and recycled fibers, if any. In-situ CaCO 3 formation gave higher brightness and much less ERIC value in ONP sheet than the case when the equivalent amount of GCC was added to the furnish.