Thermo-mechanical and impact properties of polymeric foams used for snow sports protective equipment

The thermo-mechanical and impact properties of materials used for hard-shell and soft-shell back protectors have been analysed in order to understand the mechanism of action of the foams used for protective equipment. Dynamical mechanical analysis has shown that materials used for soft-shell protectors present frequency-sensitive properties that permit to have a soft response when stressed at low speed and a hard response when subjected to a high-speed impact. Furthermore, by means of drop weight impact tests, the shock absorbing characteristics of the materials have been investigated at two temperatures pointing out the differences between soft and hard-shell protectors; in addition it has been demonstrated that the materials used for soft-shell protectors maintain their protective properties after multi-impacts on the same point.