Abstract
Flowability parameters of powders measured by a shear cell is expected to depend on shear cell size, but details of that effect are lacking. In this work, we have systematically evaluated this using a number of powders under three preshear normal stresses using a ring shear tester. The flowability index (ffc) of a limestone powder (BCR 116) exhibited relatively small differences when measured on three shear cells of different sizes, S (~9.5 cm3) < M (~30 cm3) < L (~70 cm3). However, significant differences in measured ffc of common pharmaceutical powders were observed, where ffc of powders with a median particle size >22 μm was more than 15% higher using S than M. Large differences between data from M and L were found for powders with a median particle size >125 μm. Therefore, one must exercise caution when comparing flow properties of powders characterized using different shear cells.
Original language | English (US) |
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Pages (from-to) | 555-564 |
Number of pages | 10 |
Journal | Powder Technology |
Volume | 396 |
DOIs | |
State | Published - Jan 2022 |
Bibliographical note
Funding Information:A portion of this work was conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under Award ECCS-1542202.
Publisher Copyright:
© 2021 Elsevier B.V.
Keywords
- Limestone
- Mannitol
- Microcrystalline cellulose
- Powder flowability
- Shear cell testing