Vicat softening point
Encyclopedia
Vicat softening point or Vicat hardness is the determination of the softening point
for materials that have no definite melting point
, such as plastics. It is taken as the temperature at which the specimen is penetrated to a depth of 1 mm by a flat-ended needle with a 1 square mm circular or square cross-section. For the Vicat A test, a load of 10 N is used. For the Vicat B test, the load is 50 N.
Standards to determine Vicat softening point include ASTM D 1525 and ISO 306, which are largely equivalent.
Softening point
The softening point is the temperature at which a material softens beyond some arbitrary softness. It can be determined, for example, by the Vicat method , Heat Deflection Test or a ring and ball method ....
for materials that have no definite melting point
Melting point
The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...
, such as plastics. It is taken as the temperature at which the specimen is penetrated to a depth of 1 mm by a flat-ended needle with a 1 square mm circular or square cross-section. For the Vicat A test, a load of 10 N is used. For the Vicat B test, the load is 50 N.
Standards to determine Vicat softening point include ASTM D 1525 and ISO 306, which are largely equivalent.