F. Carrasco et al., CONTROL OF RETENTION IN PAPER-MAKING BY COLLOID TITRATION AND ZETA-POTENTIAL TECHNIQUES, Wood Science and Technology, 32(2), 1998, pp. 145-155
The concentration influence of some commercial polyethylenimines, used
as retention agents, on the retention efficiency during the sheet for
mation is studied in this paper The conditions of an industrial wire e
nd have been simulated by means of a dynamic jar of exclusive design.
Measurements of the zeta potential have been taken to quantify the sur
face charge of particles and the colloid titration ratio (quotient bet
ween the cationic demand and the anionic demand of pulp slurries) has
been evaluated. Both techniques have proved convenient to monitor the
retention level; therefore, they are efficient methods to control the
retention level in the sheet formation. The univocal relation existing
between zeta potential and the logarithm of the colloid titration rat
io has been demonstrated. Finally, the variation of the level of turbu
lence has proved the importance of the hydrodynamics factors in the re
tention.