what is a plastics heat distortion temp
These Charts show the thermal deformation temperature and the softening temperature (called the âVicat softening temperatureâ) of major plastics. The heat distortion temperature is the temperature when the test piece placed in the heat medium with bending load applied reaches a specified deflection as temperature rises. The Vicat softening temperature is defined as the temperature where the needle shaped penetrator sinks into the test piece to a specified depth as temperature of the heating medium rises and specified vertical load is applied to the test piece.