Polymer Lubrication Review

Polymer Lubrication Review

Polymer Lubrication: The low thermal conductivity of polymers inhibits heat dissipation, which causes premature failure due to melting. This condition is exacerbated if the counterface material has the same or similar thermal conductivity. Two polymers in sliding contact will normally operate at significantly reduced speeds than a polymer against a metal surface. The wear rate of polymer composites is highly dependent upon the surface roughness of the metal counterfaces. In the initial operating stages, wear is significant but can be reduced by providing smooth counterfaces. As the run-in period is completed, the wear rate is reduced due to polymer film transfer or by polishing action between the sliding surfaces. Environmental factors also influence wear rate. Increased relative humidity inhibits transfer film formation in polymer composites such as PTFE, which rely on transfer film formation on counterfaces. The presence of hydrocarbon lubricants may also produce similar effects. Composites such as nylons and acetals, which do not rely on transfer film formation, experience reduced wear in the presence of small amounts of hydrocarbon lubricants.