| 摘要 |
<p>Cylindrical radially shrinkable sleeve (10) for enclosing a connection or an end termination of an electrical cable, in particular for a medium voltage cable, having an insulation surrounded by a shielding layer, the sleeve (10) comprising an outer shielding layer (16) of semi-conductive material and at least an insulation layer (14) on the inner side of the shielding layer (16), with the unit of the cylindrical layers made of permanent flexible material adapted to be retained in a radially expanded state by mechanical support means, preferably a support core, wherein the radially innermost layer is of a homogeneous material having a relative dielectric constant which is significantly larger than that of said insulation of said cable. The material is a matrix of dielectric plastic material containing microspheres which are electrically conductive either totally or only at the outer surface thereof and which have a diameter between 10 and 500 νm. The microspheres are uniformly mixed into said matrix material, with the compound having a dielectric constant equal to or larger than 3 and a dielectric strength of at least 5 kV/mm.</p> |
