Optical fiber cable having buffer coupled to armor using water-block adhesive and method

Patent metadata

Field	Value
Publication number	US-12050353-B2
Application number	US-202117315550-A
Country	US
Kind code	B2
Filing date	May 10, 2021
Priority date	Nov 21, 2018
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

Embodiments of the disclosure relate to an optical fiber cable. The optical fiber cable includes a cable jacket having a first inner surface and a first outer surface. The first inner surface defines a central bore along a longitudinal axis of the optical fiber cable. The optical fiber cable also includes optical fibers disposed within the central bore and a buffer tube surrounding the optical fibers. The buffer tube has a second inner surface and a second outer surface. The optical fiber cable also includes an armor layer disposed between the first inner surface of the cable jacket and the second outer surface of the buffer tube and a water-blocking adhesive disposed between the armor layer and the first outer surface of the buffer tube. The water-blocking adhesive extends along the longitudinal axis of the optical fiber cable and around a circumference of the buffer tube.

First claim

What is claimed is:

1. An optical fiber cable comprising:
a cable jacket comprising a jacket inner surface and a jacket outer surface, the jacket inner surface defining a central bore along a longitudinal axis of the optical fiber cable and the jacket outer surface defining an outermost surface of the optical fiber cable;
at least one optical fiber disposed within the central bore;
a buffer tube disposed within the central bore and surrounding the at least one optical fiber along the longitudinal axis, the buffer tube comprising a buffer tube inner surface and a buffer tube outer surface;
an armor layer disposed between the jacket inner surface and the buffer tube outer surface; and
a water-blocking adhesive disposed between and bonding the armor layer to the buffer tube outer surface, the water-blocking adhesive being a substantially uniform mixture comprising:
a water-insoluble component; and
a water-swellable component;

wherein the water-blocking adhesive extends along at least a portion of the longitudinal axis of the optical fiber cable and at least partially around a circumference of the buffer tube such that the water-blocking adhesive extends between the armor layer and the buffer tube outer surface with n additional layers disposed therebetween.

2. The optical fiber cable of claim 1 , wherein the armor layer comprises a plurality of corrugations.

3. The optical fiber cable of claim 2 , wherein the water-blocking adhesive adheres to the armor layer and to the buffer tube outer surface and wherein the water-blocking adhesive fills and adheres to the plurality of the corrugations to create a mechanical interlock between the buffer tube and the armor layer.

4. The optical fiber cable of claim 3 , wherein the mechanical interlock and adherence of the water-blocking adhesive to the armor layer and to the buffer tube outer surface constrains at least 12.8 MPa of contractive force.

5. The optical fiber cable of claim 1 , wherein the water-blocking adhesive is continuous around the entire circumference of the buffer tube and along the longitudinal axis of the optical fiber cable.

6. The optical fiber cable of claim 1 , wherein the water-blocking adhesive is discontinuous along the portion of the longitudinal axis along which the water-blocking adhesive extends.

7. The optical fiber cable of claim 1 , wherein the water-blocking adhesive comprises one or more gaps between sections of water-blocking adhesive that are less than 3 meters in length.

8. The optical fiber cable of claim 1 , wherein the buffer tube experiences a shrinkage of less than 75 millimeters after exposure to temperature cycling within the range of −40° C. and 70° C.

9. The optical fiber cable of claim 1 , wherein the water-blocking adhesive comprises a thickness of up to 0.8 millimeters.

10. A method of preparing an optical fiber cable comprising the steps of:
providing an optical fiber cable core comprising a buffer tube having an inner surface and an outer surface, the inner surface defining a central bore along a longitudinal axis of the optical fiber cable core, and at least one optical fiber disposed within the central bore;
forming an armor layer partially around the optical fiber cable core;
depositing, as a liquid, a water-blocking adhesive on at least one of the cable core or the armor layer; and
closing the armor layer around the optical fiber cable core such that the armor layer is bonded to the optical fiber cable core by way of the water-blocking adhesive such that at least a portion of the water-blocking adhesive extends between the armor layer and the optical fiber cable core with no tape or film disposed in between.

11. The method of claim 10 , further comprising the step of extruding a cable jacket around the armor layer after the closing step, wherein the cable jacket defines the outermost surface of the optical fiber cable.

12. The method of claim 10 , wherein the depositing the water-blocking adhesive on at least one of the cable core or the armor layer comprises depositing the water-blocking adhesive on the armor layer prior to the forming step.

13. The method of claim 10 , wherein depositing the water-blocking adhesive comprises depositing the water-blocking adhesive discontinuously on at least one of the cable core or the armor layer.

14. The method of claim 10 , wherein the armor layer comprises a plurality of corrugations, and wherein further the water-blocking adhesive is deposited on the armor layer such that the water-blocking adhesive conforms to the corrugations.

15. The method of claim 10 , wherein the forming step further comprises forming the armor layer into a U-shape at least partially around the optical fiber cable core.

16. The method of claim 10 , wherein the water-blocking adhesive is a substantially uniform mixture that comprises a water-swellable component and a water-insoluble component.

17. An optical fiber cable comprising:
a jacket structure comprising a cable jacket and optionally an armor layer surrounded by the cable jacket, the jacket structure defining a central bore along a longitudinal axis of the optical fiber cable;
at least one optical fiber disposed within the central bore;
a first layer disposed between the at least one optical fiber and the jacket structure, the first layer comprising at least one of a buffer tube or a foamed thermoplastic elastomer layer that surrounds the at least one optical fiber;
a second layer disposed between the first layer and the jacket structure;
wherein the second layer is bonded to and in contact with the first layer and one of the cable jacket or the armor layer such that the second layer adheres the first layer to the jacket structure; and
wherein the second layer is formed of a substantially uniform mixture that comprises a water-swellable component and that is configured to absorb water that enters through the jacket structure.

18. The optical fiber cable of claim 17 , wherein the cable jacket comprises an inner surface and an outer surface and wherein the jacket structure further comprises the armor layer disposed on the inner surface of the cable jacket.

19. The optical fiber cable of claim 18 , wherein the second layer adheres the first layer to the armor layer such that the first layer adheres to the jacket structure by way of the armor layer.

20. The optical fiber cable of claim 19 , wherein the armor layer comprises a plurality of corrugations, wherein further the second layer is applied to the armor layer such that the second layer is substantially conformal to the plurality of corrugations.

Assignees

• Corning Res & Dev Corp
• Corning Res And Development Corporation

Inventors

• Blazer Bradley Jerome
• Chen Yangbin
• Miller Allen Michael
• Quinn Christopher Mark
• Smith Randy Curtis

Classifications

• G02B6/4486

  Protective covering · CPC title

• G02B6/4488

  using metallic tubes · CPC title

• G02B6/4435

  Corrugated mantle · CPC title

• G02B6/44384 Primary

  the means comprising water blocking or hydrophobic materials (G02B6/4439, G02B6/4479 take precedence) · CPC title