Composite film for a fiber optic cable

Patent metadata

Field	Value
Publication number	US-2016306128-A1
Application number	US-201615190767-A
Country	US
Kind code	A1
Filing date	Jun 23, 2016
Priority date	Dec 30, 2013
Publication date	Oct 20, 2016
Grant date	—

Abstract

A fiber optic cable includes core elements, a composite film surrounding the core elements, and a jacket surrounding the composite film. The core elements include one or more optical fibers and at least one tube surrounding the one or more optical fibers. The composite film includes a first layer adjoining a second layer, where the composition of the second layer differs from the first. The composite film is relatively thin, having an average thickness over a 10-meter length of the cable that is less than half an average thickness of the jacket over the 10-meter length.

First claim

What is claimed is:

1 . A fiber optic cable, comprising:
(A) core elements comprising:
(i) an optical fiber; and
(ii) a tube surrounding the optical fiber;
(B) a composite film surrounding the core elements, wherein the composite film comprises:
(i) a first layer comprising a first extrudable polymer, wherein the first layer has an average thickness over a 10-meter length of the cable that is less than 500 micrometers, and
(ii) a second layer comprising a second extrudable polymer, wherein the composition of the second layer differs from the composition of the first layer, and wherein the first layer has an average thickness over the 10-meter length of the cable that is less than 500 micrometers, and
wherein the first layer adjoins the second layer; and
(C) a jacket surrounding the composite film, wherein the composite film is relatively thin, having an average thickness over the 10-meter length of the cable that is less than half an average thickness of the jacket over the 10-meter length.

2 . The fiber optic cable of claim 1 , wherein more than half of the first layer by weight is formed from the first extrudable polymer, and wherein more than half of the second layer by weight is formed from the second extrudable polymer.

3 . The fiber optic cable of claim 2 , wherein the composite film directly contacts the tube, and wherein the composite film directly contacts the jacket.

4 . The fiber optic cable of claim 3 , wherein the first layer of the composite film contacts the tube and wherein the second layer of the composite film contacts the jacket, whereby the jacket is separated from the first layer by the second layer.

5 . The fiber optic cable of claim 4 , wherein at least 20% of the jacket by weight is formed from the first extrudable polymer, and wherein the second layer of the composite film fully envelops the first layer such that at least the second layer blocks cohesive bonding between the first extrudable polymer of the jacket and the first extrudable polymer of the first layer.

6 . The fiber optic cable of claim 5 , wherein the first extrudable polymer is a polyethylene.

7 . The fiber optic cable of claim 6 , wherein the second extrudable polymer is a polypropylene.

8 . The fiber optic cable of claim 7 , wherein at least 20% of the tube by weight is formed from the second extrudable polymer.

9 . The fiber optic cable of claim 4 , wherein the average thickness of the composite film over the 10-meter length of the cable that is less than a fifth the average thickness of the jacket over the 10-meter length.

10 . The fiber optic cable of claim 4 , wherein each layer of the composite film has an average thickness over the 10-meter length that is less than 500 micrometers.

11 . The fiber optic cable of claim 10 , wherein the combination of the first and second layers has an average thickness over the 10-meter length that is less than 500 micrometers.

12 . The fiber optic cable of claim 11 , wherein the composite film has an average thickness over the 10-meter length that is less than 500 micrometers.

13 . The fiber optic cable of claim 4 , wherein, around the cross-sectional periphery of the composite film, the composite film takes the shape of core elements adjoining the composite film and extends in generally concave arcs over interstices between the core elements.

14 . The fiber optic cable of claim 1 , wherein the first and second layers of the composite film are bonded to one another.

15 . A fiber optic cable, comprising:
(A) core elements comprising:
(i) optical fibers,
(ii) a first tube surrounding at least one of the optical fibers,
(iii) a second tube surrounding at least another of the optical fibers,
(B) a composite film surrounding the core elements, wherein the composite film is a binder for the core elements, opposing outwardly transverse deflection of one or more of the core elements, and wherein the composite film comprises:
(i) a first layer comprising a first extrudable polymer, and
(ii) a second layer comprising a second extrudable polymer, wherein the composition of the second layer differs from the composition of the first layer, and wherein the first and second extrudable polymers are co-extrudable with one another,
wherein the first layer adjoins the second layer, and
wherein each of the first and second layers has an average thickness over a 10-meter length of the cable that is less than 500 micrometers.

16 . The fiber optic cable of claim 15 , further comprising a central strength member, wherein the core elements are stranded around the central strength member in a pattern of stranding including reversals in lay direction of the core elements, wherein the composite film loads the core elements normally to the central strength member such that contact between the core elements and central strength member provides coupling therebetween, limiting axial migration of the core elements relative to the central strength member.

17 . A fiber optic cable, comprising:
(A) core elements comprising an optical fiber; (B) a composite film surrounding the core elements, wherein the composite film comprises:
(i) a first layer comprising a first polymer, and
(ii) a second layer comprising a second polymer, wherein the composition of the second layer differs from the composition of the first layer,
(iii) powder particles partially embedded in the composite film such that the powder particles have a portion thereof submerged in the composite film passing partly through a surface plane of the composite film and another portion thereof exposed partially projecting away from the surface plane of the composite film, and
wherein the first layer adjoins the second layer, and
wherein at least some of the powder particles are positioned on an inside surface of the composite film between the composite film and the core elements; and
(C) a jacket surrounding the composite film, wherein the composite film is thin, having an average thickness over a 10-meter length of the cable that is less than half an average thickness of the jacket over the 10-meter length.

18 . The fiber optic cable of claim 17 , wherein the powder particles partially embedded in the composite film comprise super-absorbent polymer particles.

19 . The fiber optic cable of claim 18 , wherein, when dry, the super-absorbent polymer particles have an average maximum cross-sectional dimension of 500 micrometers or less.

20 . The fiber optic cable of claim 18 , wherein the amount of super-absorbent polymer particles attached to the composite film is less than 100 grams per square meter of surface area of the inside surface of the composite film.

Assignees

• Corning Optical Communications LLC

Inventors

• Chiasson David Wesley
• Mcalpine Warren Welborn
• Parker Joel Laine

Classifications

• G02B6/4433 Primary

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

• G02B6/4431 Primary

  with provision in the protective covering, e.g. weak line, for gaining access to one or more fibres, e.g. for branching or tapping (break-out terminations G02B6/4471) · CPC title

• G02B6/4434 Primary

  Central member to take up tensile loads · CPC title

• G02B6/4494

  Physics · mapped topic

• G02B6/4436

  Heat resistant · CPC title