electrical cable which includes one or more individually insulated conductors within a sheath of insulating material and an insulating filler innanfor cloak at the cable no acidic gases is developed.

摘要

1480090 Electric cable PIRELLI GENERAL CABLE WORKS Ltd 26 Nov 1975 [5 Dec 1974] 52717/74 Heading H1A An electric cable comprises at least one individually insulated conductor 10, 11, 12 within a sheath 20 of flame retardant insulating material and an insulating, flame retarding, filling material 18 between the conductors and the sheath, the materials of the conductor insulation, filling material and sheath being such that upon combustion no acidic gases are evolved and little smoke is formed. The conductor insulation may comprise non- sulphur cured ethylene-propylene rubber, crosslinked polyethylene, non-sulphur cured butyl rubber, thermoplastic rubber or thermoplastic polyethylene or flame retardent silicone rubber, flame retardent cross-linked polyethylene or thermoplastic polyethylene containing an inorganic flame retardant. The sheath may be flame retardant silicone rubber, flame retardant cross-linked polyethylene or thermoplastic polyethylene containing an inorganic flame retardant. The filling material comprises ethylenepropylene rubber and/or butyl rubber, a filler and a flame retardant; the filler is preferably ground whiting and hydrated alumina. The insulation, filling material and sheath may all be applied by extrusion. A layer of silicone rubbercoated glass tape may be provided around the sheath.