High speed armature impregnating varnishes

An armature varnish is a special type of impregnating varnish. It gives outstanding bond strength to the windings of the wire around the iron core as the armature rotates at speeds of 20,000 to 30,000 revolutions per minute. This paper suggests how this type of varnish can be formulated, tested and applied to armatures that are used for small, high speed motors, such as vacuum cleaners and hand tools. It is based on the co-operation of the varnish supplier and representatives of motor manufacturers.