Compatibility of wire enamels with epoxy encapsulants

Epoxy impregnants are being used in many applications for the environmental protection of magnet coils in motors, transformers, solenoids and reactors, and even for completed electronic circuit functional blocks. The physical properties of the epoxy resin compounds used are ideally suited, in most cases, for this purpose. These properties may be varied from rigid to flexible, transparent to opaque, and from high to low impregnating viscosity. They may also be formulated to specific degrees of toughness, impact resistance, low shrinkage, high moisture resistance, and superior resistance to a host of solvents and chemicals, notably alkalies. With a proper formulation, it is possible to apply an epoxy compound by molding, casting, dipping, vacuum impregnating or even spraying. Thus, their properties may be tailored to fit a greater variety of applications than the more widely used and less expensive impregnating varnishes.