A model powder system comprising corn starch has been subjected to
compaction agglomeration in presence of different binders like sugar
(0-20%), pre-gelatinised starch (PGS) powder (0-20%) and vegetable oil
(0-5%). The compacted masses are examined for density and different
textural parameters (linear limit of deformation and modulus of
deformability, and failure properties like failure stress/energy/strain)
employing uniaxial compression. An increase in sugar and PGS markedly
increases the failure stress, energy for failure and modulus of
deformability while showing a reverse trend for oil added samples. The
strain at failure increases with the addition of PGS and oil (6.9-14.5 and
6.9-24.4%, respectively) whereas marginal effect (6.9-8.1%) occurs with
sugar. Compacted mass having 20% PGS behaves as the toughest sample.
Cluster analysis among the textural parameters indicates a high similarity
of 85% between failure stress and energy for failure. A mechanism of
failure has been proposed for compacted mass during compression that has
been supported by microstructures.
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