Thermal stability tests (essai de stabilité thermique, essai de stabilité thermique, prova di stabilità termica) are conducted on PVC, EVA etc. based materials to obtain the behavior of thermal degradation at high temperatures.
During extrusion process many times the changeover takes longer than expected and the previous batch of raw material stays in the screw getting heated by the hot heaters up to a mx temp of 170 deg cel sometimes. As a result of this, cable manufacturers find burnt particles or fish eyes, or contamination on insulation/jacket after the extrusion of cable. This is actually caused by the quick degradation of the compound that was left in side the extrusion screw.
