Practical selection of elastomer materials for vacuum seals

Proper selection of polymer seal materials must consider restraints imposed by the application and the properties of available materials. Data and concepts presented enable the working vacuum technician to make an educated selection considering chemical and mechanical properties, outgassing, permeation, and nuclear radiation damage. Early reports on the new perfluoroelastomer Kalrez have shown problems with compression set and adhesion, but these difficulties may have resulted from improper groove design.