Paper Wrapped Wire

Kraft paper insulation is most commonly used in oil-filled transformers. The plain kraft papers are wrapped in a number of layers around conductors, to acquire the needed insulation strength. However, plain kraft paper has limitations of the flexibility and leads to breakage of insulation in tight shaping of the coils. For this purpose, kraft papers are fabricated or creped. The folds made in creping process, increases the elasticity and flexibility during shaping of coils. It also enlarges the surface area of insulation and absorbs insulating oils resulting in better insulation and heat dissipation during operation.