Bleaching Eucalyptus grandis kraft pulps using a short TCF sequence

AREA, M.C.; FELISSIA, F.E.

TAPPSA Journal

Technical Association of the Pulp and Paper Industry of Southern Africa

Año: 2007 p. 1 - 7

1029-0109

The objective of this paper is to evaluate the possibility of eliminating conventional acid Q stage with EDTA, in a Totally Chlorine Free (TCF) bleaching sequence. This article studies two short TCF bleaching sequences, applied to industrial Eucalyptus grandis kraft pulps. Results show that it is possible to eliminate the acid Q stage, replacing it by incorporating DTPMPA in brown stock washing, Op and P stages. The optical and mechanical properties of bleached industrial pulps show no significant differences when using both sequences, as final pulp characteristics are independent of the properties of previous stages. DTPMPA addition eliminated the deleterious influence of metals on TCF bleaching, and in some cases, increased mechanical properties.