Laurent Tribut and Virginie Renavant, Schneider Electric, France, presented the company’s requirements regarding flame retarded polymers for low voltage electrical equipments such as contactors and circuit breakers. These applications involve both demanding electrical and mechanical performance criteria, in parallel to high level of fire resistance because of the risk of ignition by overheating or arcing.
At present, the best solution for polyamide based polymers is organophosphorus flame retardants. Various combinations of phosphorus FRs with synergists (melamine polyphosphate, zinc borate…) were tested and demonstrated challenges in term of corrosion and abrasion during polymer injection molding, contact pollution and product ageing (especially under UV and water spraying).