What are reasons why the PTFE or Graphite pads peel off the backing plates?

In the majority of cases, bond between the material and its backing plate would become degraded in the presence of high temperatures. With PTFE, if the heat reaches to 350˚ F, the glue becomes weaker. For Graphite Slide Plates, the maximum temperature should be approximately 775˚ F.

Slide Plates On A Big Ton Spring Assembly
Slide plates on a Big Ton Spring Assembly