| 摘要 |
1,208,410. Cable insulation. KABEL UND METALLWERKE GUTEHOFFNUNGS HUTTE A.G. 26 Sept., 1969 [27 Sept., 1968], No. 47452/69. Heading H1A. A longitudinally watertight electric cable has an open-pored foamed plastics material filling the cavities between the sheath and core or within the core in which pores are present a water-swellable material, e.g. a cellulose, methyl cellulose or carboxymethyl cyllulose. A method of making the cable includes introducing a plastics, e.g. polyurethane, foam-forming mixture, before or during the application of the sheath, on to or into the cable sheath or core in which the water-swellable material is added, before the application of the sheath to a component such as a polyol of the mixture which will not cause swelling. Typically, an isocyanate component and a polyol component of the polyurethane foam forming mixture are mixed in a proportion between 1:1 and 1: 3 and between 10 and 20% of cellulose is added to the polyol component. Alternatively a previously-prepared foamed plastics material mixed with a water-swellable material is used. |
