Abstract: In a process and a material for producing an electrically insulating sheathing around a junction between electrically conductive elements, the material comprises first and second layers which have different melting points and which are disposed around the junction in such a way that the layer having the lower melting point constitutes an inner layer around the junction while the layer having the higher melting point is disposed on the outside of the inner layer. The material is pressed around the junction by means of ultrasound welding, with the inner layer softening at least to such an extent that, under the pressure applied thereto by the outer layer, the inner layer fills any spaces between the junction and the outer layer, and the outer layer forming a sealing enclosure around the inner layer and the junction.