PULP-BLEACHING OF DEINKED PULP-CONTAINING CRAFT PULP

摘要

PURPOSE:To carry out the subject bleaching of high whiteness and low undeinked fiber content in a condition where pollution load of bleaching waste water is low by adding a specified amount of deinked pulp of unbleached pulp- containing waste paper to unbleached craft pulp and subsequently carrying out multi-step bleaching. CONSTITUTION:Deinked pulp of unbleached pulp-containing waste paper is added to unbleached craft pulp containing a cocking waste liquid of pH12 and 60 deg.C so that kappa number after mixing may be =60. Enzymatic delignification is carried out and multi-step bleaching is further carried out, thus obtaining the objective pulp bleaching.