Abstract: A viscous sealing material is applied to a communications cable by being forced out of a container by means of a heatable pressure plate having a bore and a pump adjacent to the bore; the sealing material is conveyed by the pump through a conduit to a chamber, in which the sealing material is introduced under pressure into and around an already stranded cable core; the pressure plate includes a plurality of preferably helically coil electrical heating elements separated from each other and projecting therefrom for penetrating into the sealing material in the container when the pressure plate applies pressure to the sealing material so that it is progressively liquified and can be pumped out of the container.