Frictional heating calculations for polymers

Abstract

In a previous study, the authors highlighted the importance of estimating flash temperature at the contact surface of a polymer rubbing against steel. Subsequently a calculation method based on experimental tests was developed. The aim of this work is the validation of such method on different kinds of polymers, such as Nitrile-Butadiene Rubber (NBR), Thermoplastic Polyurethane (TPU) and Polytetrafluoroethylene (PTFE). The characteristics of the materials are analyzed by means of Thermo Gravimetric (TGA) and Differential Scanning Calorimetry (DSC) analyses. Frictional tests are performed on an Optimol SRV tribometer in high frequency reciprocating motion. The viability of the calculation method and its limits are herein explained.

Thermal analysis and tribological investigation on TPU and NBR elastomers applied to sealing applications

“…thermal equilibrium will be reached faster in the NBR. In the previous research on PTFE, the authors highlighted the importance of taking into account the variation of thermal properties along temperature [14,15]. In this case, it was seen that such variations along the temperature working range have negligible effect on the calculations.…”

“…Even if the contact area significantly affects the results obtained, there are no standard criterion and each model uses different approaches [9]. In the case of polymers, contact temperature estimations are even more complex as their thermo-mechanical properties are strongly influenced by temperature [10][11][12][13][14][15][16]. The importance of considering the evolution of material properties in the case of Polytetrafluoroethylene (PTFE) polymers has been already demonstrated [14,15].…”

“…In the case of polymers, contact temperature estimations are even more complex as their thermo-mechanical properties are strongly influenced by temperature [10][11][12][13][14][15][16]. The importance of considering the evolution of material properties in the case of Polytetrafluoroethylene (PTFE) polymers has been already demonstrated [14,15]. In particular, Tzanakis et al [12] studied the effect of roughness, friction coefficient, contact pressure and velocity on the flash temperatures generated on a PTFE composite elastomer tip seal in contact with a high carbon steel plate under dry sliding conditions.…”