PROCESS IN ORDER TO IMPROVE OR MAINTAIN THE BRIGHTNESS OF PAPER CONTAINING MECHANICAL PULP

摘要

The invention relates to a process to improve or maintain the brightness of paper made of a bleached mechanical pulp containing an inorganic filler where a suspension of the filler is treated with a chelating agent and/or an inorganic ion exchange product to thereby form complexes of and/or inactivate the undesirable metal ions present in the suspension.