Optical fiber coating die with reduced wetted length

Patent metadata

Field	Value
Publication number	US-11524920-B2
Application number	US-202017112192-A
Country	US
Kind code	B2
Filing date	Dec 4, 2020
Priority date	Jan 24, 2017
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

An optical fiber coating apparatus that provides increased gyre stability and reduced gyre strength, thereby providing a more reliable coating application process during fiber drawing includes a cone-only coating die having a conical entrance portion with a tapered wall angled at a half angle α, wherein 2°≤α≤25°, and a cone height L1 less than 2.2 mm, and a cylindrical portion having an inner diameter of d2, wherein 0.1 mm≤d2≤0.5 mm and a cylindrical height of L2, wherein 0.05 mm≤L2≤1.25 mm; a guide die having an optical fiber exit, the guide die disposed adjacent the cone-only coating die such that a wetted length (L5) between the optical fiber exit of the guide die and the entrance of the cone-only coating die is from 1 mm to 5 mm; and a holder for holding the cone-only coating die and the guide die in a fixed relationship defining a coating chamber between the guide die and the cone-only coating die, the coating chamber having an inner radius L6 from the optical fiber axis to an inner wall of the holder that is from 3 mm to 10 mm.

First claim

What is claimed is:

1. An optical fiber coating apparatus comprising:
a cone-only coating die having a conical entrance portion with a tapered wall angled at a half angle α, wherein 2°≤α≤25°, and a cone height L 1 less than 2.2 mm, and a cylindrical portion having an inner diameter of d 2 , wherein 0.1 mm≤d 2 ≤0.5 mm and a cylindrical height of L 2 , wherein 0.05 mm≤L 2 ≤1.25 mm;
a guide die having an optical fiber exit, the guide die disposed adjacent the cone-only coating die such that a wetted length L 5 between the optical fiber exit of the guide die and a cone portion of the cone-only coating die is between 1 mm and 5 mm; and
a holder for holding the cone-only coating die and the guide die in a fixed relationship defining a coating chamber between the guide die and the cone-only coating die, the coating chamber having an inner radius L 6 from the optical fiber axis to an inner wall of the holder that is from 6 mm to 10 mm.

2. The apparatus of claim 1 , wherein the inner radius L 6 is from 6 mm to 9.5 mm.

3. The apparatus of claim 2 , wherein the inner radius L 6 is from 7 mm to 9 mm.

4. The apparatus of claim 1 , wherein the wetted length L 5 is less than 4.5 mm.

5. The apparatus of claim 1 , wherein the wetted length L 5 is less than 3.5 mm.

6. The apparatus of claim 1 , wherein the cone height L 1 is between 0.25 mm and 2.0 mm.

7. The apparatus of claim 1 , wherein the cone-only coating die is configured to have a lubrication pressure that is less than 500 psi.

8. The apparatus of claim 1 , wherein a gyre that is formed in the coating chamber is configured to have a maximum temperature that is less than 175° C.

9. The apparatus of claim 8 , wherein the gyre is configured to have a maximum temperature that is less than 100° C.

Assignees

• Corning Inc

Inventors

• De Sumitava
• Moore Robert Clark
• Neilson Douglas Gregg
• Tandon Pushkar

Classifications

• C03C25/18 Primary

  Extrusion · CPC title

• C03C25/105 Primary

  Organic claddings · CPC title

• C03C25/1065

  Multiple coatings · CPC title

• C03C25/285

  Acrylic resins · CPC title