Slotted-plate apparatus to measure yield stress of suspensions

Autor: K. D. Papadopoulos, L. Zhu, D. De Kee
Rok vydání: 2004
Předmět:
Zdroj: Review of Scientific Instruments. 75:737-740
ISSN: 1089-7623
0034-6748
DOI: 10.1063/1.1645634
Popis: A procedure is described to build a slotted-plate device to directly measure the static yield stress of a suspension. The technique involves a balance as well as a linear motion platform. A slotted plate is suspended from the balance and is vertically positioned in a suspension sample which stands on the platform. The yield stress is determined from the point where initially constant slope of the force versus platform travel distance changes. Wall effects associated with the original plate yield-stress instrument were minimized by opening a series of slots on the plates. Yield-stress values of both high-concentration (40, 50, 60, and 70 wt % TiO2) and low-concentration (2, 3, and 5 wt % bentonite) aqueous suspensions were measured. Very small yield-stress values (down to ∼10−4 Pa) could be determined with our slotted-plate device. Other methods, such as the popular vane technique, could not measure yield-stress values of the bentonite suspensions for concentrations less than 7 wt %, corresponding to a yie...
Databáze: OpenAIRE