Vicat Softening Point

Vicat Softening Point a good way to compare the heat softening characteristics of polyethylenes. Also, it may be used with other thermoplastics.

The apparatus for testing Vicat softening point consists of a temperature regulated oil bath with a flat ended needle penetrator so mounted as to register degree of penetration on a gauge. A specimen is placed with the needle resting on it. The temperature of the bath (preheated to about 50 °C lower than anticipated Vicat softening point) is raised at the rate of 50 °C/hr. or 120 °C/hr. The temperature at which the needle penetrates 1 mm. is the Vicat Softening Point. ASTM D-1525.