The sensitive dependence of sealing elastomers on lubricants

<m:p>The design of elastomer seals for bearings and pumps requires the selection of the friction partner and lubricant. This study investigates the influence of swelling and spreading behavior on the tribological behavior of NBR systems. Interaction tendencies are described by the energies of interaction and spreading, which are determined by means of contact angle measurements. Intensive swelling was observed in elastomers with a high tendency to solve or interact. The elasticity and spreading energy are decisive for the formation of the elastic length of the adhesive contact. Highly deformable elastomers form an adhesive contact whose length influences the friction. If the elasticity of swollen elastomers is low, friction and wear increase. For elastomers with low lubricant absorption, the spreading tendency determines the friction. A characteristic speed shows at which a transition to forced wetting occurs. Polar lubricants as well as water-based lubricants show similar dependencies to dry systems, which still needs to be verified. For greases, the tendency to spreading and loosening was calculated for base oils, with non-spreading contacts predominating. In thermoplastic systems, the swelling tendency is dominant.</m:p>