| 摘要 |
1535840 Electric cable NORTHERN TELECOM Ltd 4 Feb 1976 [26 Feb 1975] 04442/76 Heading H1A A cable 20 comprising conductors 12 and a jacket 14 has the interstices within the jacket and between the conductors at least partially filled with a mixture of a hydrophobic and a hydrophilic powder to protect against water entry into and migration along the cable; the hydrophilic powder forms on contact with the water a viscous, non-swelling material. The hydrophobic powder may be a long-chain fatty acid coated calcium carbonate and make up 8 to 30% by weight of the mixture while the hydrophilic powder may be a high molecular weight polyarylamide making up the remainder. Each conductor may be coated with a hydrophobic oil, e.g. a low viscosity paraffin oil. The cable may have a core wrap 22, a metal sheath 24 and a layer 26 of the powder mixture. |
