TAPPI T 697 cm-12 describes an accelerated laboratory procedure for predicting the relative storage life of aqueous kaolin clay dispersions by measuring low-shear viscosity increases during elevated-temperature storage. The method covers equipment, calibration, sampling assumptions, controlled storage, viscosity measurement, reporting requirements, precision, and relevant considerations such as pH, solids content, sedimentation, and dispersant stability.
It is intended for laboratories and technical professionals involved in paper manufacturing, mineral pigment testing, coating materials, slurry handling, and quality control. The document is provided as a four-page PDF and includes guidance for using rotating spindle viscometers, drying ovens, temperature-controlled storage, and sealed sample containers.
Application Scope: Primarily applicable to aqueous kaolin clay-water suspensions used in paper manufacturing; use with other mineral pigment slurries or coating color formulations may be possible, but precision and reproducibility are not established for those systems.
