Some plastics that could be considered are:-
Polyurethane
Cross linkable Polyethylene or XLPE
Ultra High Molecular Weight Polyethylene UHMWPE
Low Density Polyethylene LDPE
High Density Polyethylene HDPE
Nylon or Nylatron or Zytel or PA6 or PA66
Acetal or Delrin or Celcon or POM
They are listed from the most compliant to the hardest.
Durability ranking will be dependant on the mode of failure. If they fail by pounding out, the hardest ones will most probably be the most durable, unless the suspension operates in a bind, and then the extra compliance of the softer ones will help to reduce the point pressures.
If they fail by melting, the nylon will be the most durable.
If they wear due to inclusion of dirt, the softest ones will be the most durable.
The softest ones will give the quietest most isolated ride, but the hardest ones will give the most accurate suspension control.
The final choice will depend on a complex compromise considering bearing area vs load, surface speed, compliance required, compliance (or lack thereof) desired, environment of operation, life expectancy.
Regards
pat pprimmer@acay.com.au
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