Author(s)

B. Pinedo, M. Hadfield, M. Conte, A. Igartua

Abstract

The main limitation of polymers and subsequently of seals is their thermal resistance. Temperature rise on surfaces of bodies in contact due to frictional heating phenomena may influence considerably the tribological response and failure mechanisms of components. Moreover, high temperatures may cause structural changes of materials, as well as chemical reactions, oxidation and material degradation or melting. An experimental study of surface temperature rise of elastomers sliding against steel parts is herein presented. In this work, two of the most common polymers used in the sealing industry have been considered: NBR (Nitrile-Butadiene Rubber) and TPU (Thermoplastic Polyurethane). Surface temperatures and their evolution were measured during sliding of polymeric samples against steel cylinders by means of a high precision infrared thermo-camera. Friction coefficients were also acquired in order to study the effect of friction in relation to temperature rise. Moreover, steel cylinders with two different roughness and surface conditions were tested. Tests were carried out in absence of lubricant for an improved visualization of the temperature field. Test conditions and surface properties were selected so that they are inside the range of conditions recommended by seal manufacturers.

Keywords

frictional heating, polymer, contact temperature, roughness