| Plasticity is t 11e most important though least understood
property of clays. Because of this property, it is possible to
shape moistened clay into wares. In certain processes, like
the dry pressing, this property is not used to its full extent but
ware m1de by such processes is very limited. Plasticity is
the susceptibility to and retentivity of deformation of a mass
formed by a slight force. The first aspect of plasticity refers
to softness and the second to permanent set. Plasticity is
the property of being m0uldable under pressure, and retaining
the shape when the pressure is relieved. It is the property,
which enables a material to be deformed · continuously and
permanently without rupture during the application of a
force which exceeds the yield value of the material, The term
workability is sometimes used to indicate the case with which
a clay can be made to spre,td or otherwise change shape, but
it is not identical with plasticity. |
