Synthetic materials as wire insulation

Preceded by a historical outline of the use of synthetic materials for insulating electric conductors, this article reviews in some detail the use of these materials on magnet wire, with particular reference to the recent introduction of the new insulating coating called “Formex” which is a synthetic resin embodying polyvinyl formal and is applied to wires by the floating die method. Comparative tests show this new material to be markedly superior to former enamel insulating coatings.