Process of extrusion-coating the central core with an insulator of high pressure-processed polyethylene
US4078111A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1976 |
| Grant date | Mar 7, 1978 |
| Priority date | — |
| Expiry date | May 20, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/919
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Provided hereinbelow is a process of extrusion-coating the central core, said core being used in a submarine coaxial cable, with an insulator of high pressure-processed polyethylene having a density of from 0.925 to 0.940 g/cm.sup.3 and a melt index of from 0.01 to 0.3 g/10 min with advantages in that said coaxial cable is allowed to be placed on a sea bottom of not less than 500 meters in depth and to effectively transmit alternating current signals with a maximum frequency of not less than 30 MHZ, while attenuation of said signals is reduced, and thus, said coaxial cable has a transmission capacity of not less than 3000 circuits or channels with a frequency band of from 3 to 6 KHz per each circuit or channels, wherein the insulator-covered-core is continuously extruded from an extruder and then is gradually cooled in cooling water troughs to room temperature so that the water content of said insulator, without formation of voids between said central core and said insulator, is reduced by as much as possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.