With the increasing use of plastic parts in many areas of modern manufacturing, it has become mandatory for o-rings to effectively seal against an ever-widening variety of plastic as well as metal surfaces.
The problem encountered with o-ring contact with plastics is the adverse effect of compound ingredients, such as plasticizers, inducing surface cracking (“crazing”) in plastics. This crazing may eventually lead to physical weakness and/or failure of the plastic structure.
Best Choices
Ethylene-Propylene, Fluorocarbon and Silicones; special formulated Nitriles can be used. Normal Nitriles use the same plasticizers that soften most plastics. It is very important to identify when a seal material is going to be used with plastics.
NOTE: The above listed information is intended to be used as a general guide only. Please contact us for specific application information.