Historical
ISO 306:1994
Plastics - Thermoplastic materials - Determination of Vicat softening temperature (VST)
Specifies four methods for the determination: method A50 using a force of 10 N and a heating rate of 50 °C/h, method B50 using a force of 50 N and a heating rate of 50 °C/h, method A120 using a force of 10 N and a heating rate of 120 °C/h, method B120 using a force of 50 N and a heating rate of 120 °C/h. The principle is determining the temperature at which a standard indenter penetrates 1 mm into the surface. The methods are applicable only to thermoplastics, for which they give a measure of the temperature at which the thermoplastics start to soften rapidly.
Content Provider
International Organization for Standardization [iso]