| 摘要 |
<p>Longitudinal sealing device for use in electrical power cables as in the Parent Patent consists of a substance which swells in the presence of water (I). It is arranged as rings between the metal screen and the semiconducting layer. The rings are pref. bonded to the screen using a heat-fusible compsn. (II). (I) is pref. a cellulose deriv. or a starch-acrylonitrile copolymer. (II) pref. comprises 40-70% of ethylene/vinyl acetate copolymer, 15-30% of hydrogenated collophany, 5-20% collophany resin, and up to 40% graphite.</p> |
