Method and apparatus for manufacturing carbon fibers

Patent metadata

Field	Value
Publication number	US-11525193-B2
Application number	US-202017004399-A
Country	US
Kind code	B2
Filing date	Aug 27, 2020
Priority date	Jun 5, 2017
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A method and apparatus for manufacturing a carbon fiber. Pressure is applied to a filament to change a cross-sectional shape of the filament and create a plurality of distinct surfaces on the filament. The filament is converted into a graphitic carbon fiber having the plurality of distinct surfaces. A plurality of sizings is applied to the plurality of distinct surfaces of the graphitic carbon fiber in which the plurality of sizings includes at least two different sizings.

First claim

What is claimed is:

1. An apparatus comprising:
a roller system for applying pressure to a filament to change a cross-sectional shape of the filament and create a plurality of distinct surfaces;
a heat system for converting the filament into a graphitic carbon fiber; and
a plurality of surface sizing applicators for applying a plurality of sizings to the plurality of distinct surfaces of the graphitic carbon fiber, the plurality of surface sizing applicators comprising at least:
a first sizing applicator configured to apply a first sizing of the plurality of sizings to a first surface of the plurality of distinct surfaces of the graphitic carbon fiber, and
a second sizing applicator configured to apply a second sizing of the plurality of sizings to a second surface of the plurality of distinct surfaces of the graphitic carbon fiber, the second sizing being different from the first sizing.

2. The apparatus of claim 1 , wherein a surface sizing applicator in the plurality of surface sizing applicators includes at least one of a sizing application roller, a sizing application spray, a sizing application brush, a chemical bath.

3. The apparatus of claim 1 further comprising:
a tension system for tensioning the filament at least one of prior to heating the filament, while heating the filament, or after heating the filament.

4. The apparatus of claim 1 , wherein the first and second surface sizing applicators are configured to apply the first and second sizings to the first and second surfaces of the graphitic carbon fiber simultaneously.

5. The apparatus of claim 1 , wherein:
the first surface sizing applicator is configured to apply the first sizing on a top surface of the graphitic carbon fiber; and
the second surface sizing applicator is configured to apply the second sizing on a bottom surface of the graphitic carbon fiber.

6. The apparatus of claim 1 , wherein the heat system uses a first level of heat to convert the filament into an amorphous carbon fiber and a second level of heat to convert the filament into a graphitic carbon fiber.

7. The apparatus of claim 6 , wherein the amorphous carbon fiber has a gray color and wherein the graphitic carbon fiber has a black color.

8. The apparatus of claim 6 , wherein a middle interior portion of the graphitic carbon fiber remains amorphous.

9. The apparatus of claim 1 , wherein the filament is comprised of a polyacrylonitrile polymer.

10. The apparatus of claim 1 , wherein the roller system comprises at least one roller having a powder coating to protect the filament and to prevent the filament from sticking to the roller system.

11. The apparatus of claim 1 , wherein the heat system comprises:
a first oven for heating the filament at a first level of heat to form an amorphous carbon fiber; and
a second oven for heating the filament at a second level of heat to form the graphitic carbon fiber.

12. The apparatus of claim 1 further comprising:
an output system having an opening through which a polymer is extruded to form the filament.

13. The apparatus of claim 1 , wherein the first and second surface sizing applicators are sizing application rollers.

14. The apparatus of claim 1 , wherein:
the first surface sizing applicator comprises a first chemical bath for holding the first sizing and contacting the first surface of the graphitic carbon fiber with the first sizing; and
the second surface sizing applicator comprises a second chemical bath for holding the second sizing and contacting the second surface of the graphitic carbon fiber with the second sizing.

15. The apparatus of claim 14 , wherein the first sizing and the second sizing are mutually attractive to prevent undesired twisting of the graphitic carbon fiber.

16. The apparatus of claim 1 , wherein the first and second sizings include respective two different epoxy resins and wherein using the two different epoxy resins enables chemical alignment of tetra-functional epoxy molecules in the two different epoxy resins to improve a uniformity of the graphitic carbon fiber.

17. An apparatus comprising:
a roller system for applying pressure to a filament to change a cross-sectional shape of the filament and create a plurality of distinct surfaces;
a heat system for converting the filament into a graphitic carbon fiber; and
a plurality of surface sizing applicators for applying a plurality of sizings to the plurality of distinct surfaces of the graphitic carbon fiber such that each sizing of the at least two different sizings contacts a respective distinct surface of the plurality of distinct surfaces of the graphitic carbon fiber;
wherein the plurality of surface sizing applicators comprises:
a first sizing applicator configured to apply a first sizing of the at least two different sizings to a respective first distinct surface of the plurality of distinct surfaces, and
a second sizing applicator configured to apply a second sizing of the at least two different sizings to a respective second distinct surface of the plurality of distinct surfaces, the second sizing being different from the first sizing.

18. The apparatus of claim 17 , wherein the at least two different sizings include two different epoxy resins and wherein using the two different epoxy resins enables chemical alignment of tetra-functional epoxy molecules in the two different epoxy resins to improve a uniformity of the graphitic carbon fiber.

19. The apparatus of claim 17 , wherein the first sizing and the second sizing are mutually attractive to prevent undesired twisting of the graphitic carbon fiber.

20. A fiber processing system comprising:
a first chemical bath that includes a first sizing;
a second chemical bath that includes a second sizing that is different from the first sizing;
a first surface sizing applicator for picking up the first sizing from the first chemical bath to apply the first sizing to a first surface but not a second surface of a graphitic carbon fiber; and
a second surface sizing applicator for picking up the second sizing from the second chemical bath to apply the second sizing to the second surface of the graphitic carbon fiber.

Assignees

• Boeing Co

Inventors

• Humfeld Keith Daniel
• Hartshorn Scott

Classifications

• D01D10/00

  Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected (finishing D02J) · CPC title

• D01F9/32

  Apparatus therefor · CPC title

• D01F9/22 Primary

  from polyacrylonitriles · CPC title

• D01D5/16 Primary

  using rollers, or like mechanical devices, e.g. snubbing pins · CPC title

• D01F9/12

  Carbon filaments; Apparatus specially adapted for the manufacture thereof · CPC title