Cut & chip wear of rubbers in a range from low up to high severity conditions

The development of cut and chip (CC) resistant rubber articles, composed of rubber blends, requires a detailed understanding and a controlled estimation of the CC behavior of each separate rubber component within the blend in a wide range of severity conditions. This study is focused on comparative CC investigations of NR, SBR and NR/SBR (50:50) rubber blends using an Instrumented Chip and Cut Analyser (ICCA, Coesfeld GmbH, Germany) in a broad range of loading conditions. We show the results for the CC effects dependant on the applied normal forces from 90 to 200 N during cyclic impact damaging and the evolution of the temperature on the surface of the damaged specimen. We find significant differences between the used rubbers regarding dependence on the damage parameters and temperature on the normal load which determines the severity to which the rubber is exposed. In the case of NR evolving the CC damage and temperature goes through a maximum at critical values of the impacting normal load. This effect is briefly discussed in the context of the appearance of strain-induced crystallization (SIC) in the NR during cyclic impacts above a critical level. The results impressively explain the empirical preference for NR or NR-blends in practice when it comes to minimizing CC wear.