Effect of a Wet-End Additive on the Components of Formation of Tissue, 2001 Papermakers Conference Proceedings

Jean-Philippe Bernié, W.J. Murray Douglas--Although papermaking parameters strongly affect formation, satisfactory relationships have not been established because of the difficulty of quantifying formation. Formation test instruments which have been available provide some single-number formation index which is blind to scale of formation. In a new technique the intensity of local nonuniformity of formation is partitioned into its components as a function of scale of formation over the 0.6mm-37mm range of scale. With this technique it can now be determined which papermaking parameters affect specific components of formation, and by how much.

This "components of formation - scale of formation" method was used to characterize the effect on napkin formation of a wet-end tissue softening additive. The evolution of these formation components as a function of the dosage of additive was determined, along with the stability of the CD profile of formation under these conditions. There is no general CD profile of formation, as this profile changes completely with scale of formation. There is an optimum dosage of the additive for formation, but formation is improved only over a limited range of scale of formation. At higher dosage of the softening additive the quality of formation is significantly degraded, for which strength properties would be correspondingly degraded.

Wet-end additives used to improve specific aspects of product quality may have unintended negative effects on some components of formation and thereby on formation dependant strength properties. Only by partitioning formation nonuniformity into its components using this new technique can these unintended effects of additives be correctly determined.