VICAT / HDT 3-station Test Equipment – VHDT-30
Determination of Vicat softening temperature and heat deformability temperature
Thermoplastics do not have a specific melting point that defines the transit from solid to liquid with accuracy. It is rather a gradual softening with the increase in temperature.
For this reason, the Vicat softening temperature was introduced as a substitute value for the melting point in the measurement sector. This value describes the temperature at which a circular indenter of 1 mm² in section, under a standardized load of 10 N or 50 N, penetrates exactly 1 mm into the specimen. The Vicat softening temperature is standardized in ISO 306 and ASTM D 1525.
Another magnitude to be measured is the temperature of deformability by heat at which a prismatic specimen is subjected to bending and heated with a certain temperature increase. When reaching the deformability temperature, the specimen has reached a deflection determined by the norm. Since this result given by the temperature depends on the load selected, the geometry of the specimen, the heating speed and the flexure chosen, the bending temperature under load represents an applicable value for comparing different materials with each other. The measurement of the deformability of plastics at temperature may be overlapped by internal material stresses. The procedure is defined in ISO 75 and ASTM D 648 standards.
Computerized with software that represents in DEFLEXION / TEMPERATURE Graph
DEFORMATION measurement using precision LVDT sensors
INDIVIDUAL TEMPERATURE probes placed next to the samples
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