Flame-retardant optical cable for air-blown installation

Patent metadata

Field	Value
Publication number	US-9658418-B2
Application number	US-201214420185-A
Country	US
Kind code	B2
Filing date	Aug 8, 2012
Priority date	Aug 8, 2012
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An optical cable has a cable core including at least one tube loosely accommodating optical fibers, the at least one tube being accommodated within a jacket embedding at least two strength members, the cable core and the jacket comprising combustible material. A ratio of core combustible material/jacket combustible material is lower than 60 vol %. The jacket is made of a composition having hardness of at least 60 Shore D and a LOI higher than 35%.

First claim

The invention claimed is:

1. An optical cable for air-blown installation, comprising:
a cable core comprising at least one tube loosely accommodating optical fibers; and
a single outermost jacket embedding at least two strength members and surrounding the at least one tube in a central-loose-tube configuration, wherein:
the cable core and the jacket comprise combustible material, and a ratio of core combustible material/jacket combustible material is lower than 60 vol %;
the cable has an outer diameter in a range from 6.0 mm to 10.5 mm and contains optical fibers in a range from 24 to 288; and
the jacket is made of a low smoke zero halogen material having hardness of at least 60 Shore D and a LCI higher than 35% and at most 45%.

2. The optical cable according to claim 1 , wherein each tube loosely accommodates from 1 to 48 optical fibers.

3. The optical cable according to claim 1 , comprising from 1-72 tubes.

4. The optical cable according to claim 1 , wherein the tube has a wall thickness of from 0.030 mm to 0.125 mm.

5. The optical cable according to claim 1 , wherein a ratio of core combustible material/jacket combustible material is equal to or higher than 10 vol %.

6. The optical cable according to claim 1 , wherein the cable jacket is made of a composition having hardness of 75 shore D at most.

7. The optical cable according to claim 1 , wherein the cable jacket is made of a composition having a LOI of at least 40%.

8. The optical cable according to claim 1 , wherein the cable jacket has a wall thickness of from 1.0 mm to 2.0 mm.

9. The optical cable according to claim 1 , wherein the cable jacket is made of a polymeric composition which is a mixture comprising from 70 wt % to 90 wt % with respect to the total mixture weight of one or more polymers: and from 10 phr to 40 phr of one or more flame retardant inorganic fillers.

10. The optical cable according to claim 1 , wherein the cable jacket is made of a polymeric composition which is a mixture comprising at least one polyethylene polymer.

11. The optical cable according to claim 1 , wherein the cable jacket is made of a polymeric composition which is a mixture comprising at least one inorganic hydroxide flame retardant filler.

12. The optical cable according to claim 1 , wherein the optical fibers are between 24 and 72 in number and the outer diameter is about 6.0 mm.

13. The optical cable according to claim 1 , wherein the optical fibers are 96 in number and the outer diameter is about 6.5 mm.

14. The optical cable according to claim 1 , wherein the optical fibers are 144 in number and the outer diameter is about 8.0 mm.

15. The optical cable according to claim 1 , wherein the optical fibers are 192 in number and the outer diameter is about 8.5 mm.

16. The optical cable according to claim 1 , wherein the optical fibers are 288 in number and the outer diameter is about 10.5 mm.

Assignees

• Ceschiat Davide
• Maritano Mauro
• Prysmian Spa

Inventors

• Ceschiat Davide
• Maritano Mauro

Classifications

• G02B6/4438 Primary

  for facilitating insertion by fluid drag in ducts or capillaries · CPC title

• G02B6/4433

  Double reinforcement laying in straight line with optical transmission element · CPC title

• G02B6/4436 Primary

  Heat resistant · CPC title

• G02B6/46

  Processes or apparatus adapted for installing {or repairing} optical fibres or optical cables (installation of cables containing electric conductors and optical fibres H02G) · CPC title