Rubber compounds can be formulated for different electrical properties. Conductive grades use suitable fillers to create electrical pathways through the material. An ordinary cable-protection grommet should not be assumed to be conductive or electrically insulating without a specification.
Filler selection
Graphite, conductive carbon-based fillers and suitable metal-based fillers are examples used in conductive elastomers. Performance depends on the filler type, loading, dispersion and interaction with the polymer. Adding a conductive ingredient does not automatically produce the required resistance in a finished part.
Specify the electrical function
Identify whether the application requires insulation, static dissipation or electrical continuity. Define the relevant resistance measurement and test conditions, including contact geometry where applicable. Mechanical fit, compression and aging can also affect performance in an assembly.
Select a documented compound and verify the finished component under the intended conditions. Do not substitute a conductive grade into an insulation application solely because the dimensions match.
