Chemical composition of filler rods for use in optical fiber cables

Patent metadata

Field	Value
Publication number	US-9411116-B2
Application number	US-201314011292-A
Country	US
Kind code	B2
Filing date	Aug 27, 2013
Priority date	Aug 29, 2012
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

The present disclosure provides optical fiber cable having one or more filler rods. The filler rods have higher melting temperature than conventional filler rods. For some embodiments, the filler rods are made from a blend of polyethylene and polypropylene.

First claim

What is claimed is:

1. An optical fiber cable comprising:
an elongated buffer tube;
an optical fiber in the buffer tube;
an elongated filler rod comprising:
a blend of polyethylene (PE) and polypropylene (PP)
wherein the blend is thermodynamically unstable; and

a cable jacket covering the buffer tube and the filler rod.

2. The optical fiber cable of claim 1 , wherein the PE comprises at least 20 wt. % of the filler rod.

3. The optical fiber cable of claim 2 , wherein the PE comprises at least 50 wt. % of the filler rod.

4. The optical fiber cable of claim 1 , wherein the PE is high density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE) or medium density polyethylene (HDPE).

5. The optical fiber cable of claim 1 , wherein the PP is an impact-modified PP copolymer or unmodified PP.

6. The optical fiber cable of claim 1 , wherein the PE and PP in the blend are not covalently bonded to each other.

7. The optical fiber cable of claim 1 , wherein the blend is a macroscopically homogenous mixture of the PE and PP.

8. The optical fiber cable of claim 1 , wherein the filler rod is a foamed filler rod.

9. The optical fiber cable of claim 1 , wherein the filler rod does not adhere to a molten cable jacket when the filler rod is covered by the molten cable jacket.

10. The optical fiber cable of claim 9 , wherein temperature of the molten cable jacket is approximately between 185° C. and 220° C. when the filler rod is directly in contact with the molten cable jacket.

11. The optical fiber cable of claim 1 , wherein the filler rod sustains its shape when the filler rod is covered by a molten cable jacket.

12. The optical fiber cable of claim 1 , wherein a cross sectional area of the filler rod is approximately the same as a cross sectional area of the buffer tube.

Assignees

• Ofs Fitel Llc

Inventors

• Weimann Peter A

Classifications

• G02B6/4483

  Injection or filling devices · CPC title

• G02B6/441 Primary

  built up from sub-bundles (G02B6/4429, G02B6/4439, G02B6/4479 take precedence) · CPC title

• G02B6/4436 Primary

  Heat resistant · CPC title

• G02B6/4479

  Manufacturing methods of optical cables · CPC title