Description

TAPPI T697 – Accelerated test for viscosity stability of clay slurries

This method describes a procedure for predicting the relative storage life of aqueous kaolin clay dispersions by measuring viscosity increase during storage at an elevated temperature.

Viscosity is measured by a low-shear rotating spindle apparatus as described in Appendix A of TAPPI T648 Viscosity of Coating Clay Slurry. This procedure does not describe methods for determining dispersant requirements of clays, nor does it describe dry clay slurrying procedures. It describes only the testing procedures for a given clay slurry.

This procedure does not describe a method for determining the viscosity stability of other pigmentslurries or for coating colors; however, this method may be useful for such systems.