COMPOSITE POLYMER FIBERS

• US 20080152282A1
• Filed: 03/05/2008
• Published: 06/26/2008
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Breister, James C., Ouderkirk, Andrew J., Thunhorst, Kristin L., Fleming, Patrick R., Kopecky, William J., Brott, Robert L., Wilson, Bruce B., Stumo, Roger J., Chou, Yeun-Jong, North, Diane, Benson, Olester
• Granted Patent: US 7,738,763 B2
• Time in Patent Office: Days
• US Class Current: 385/36
• CPC Class Codes: D01D 5/36 Matrix structure; Spinnerette packs therefor
• CPC Class Codes: D01F 8/14 with at least one polyester as constituent
• CPC Class Codes: G02B 1/045 Light guides
• CPC Class Codes: G02B 5/3008 comprising dielectric particles, e.g. birefringent crystals embedded in a matrix
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/02347 Longitudinal structures arranged to form a regular periodic lattice, e.g. triangular, square, honeycomb unit cell repeated throughout cladding
• CPC Class Codes: G02B 6/02352 Complex periodic lattices or multiple interpenetrating periodic lattices, e.g. unit cell having more than two materials, partially internally coated holes, for multiple bandgaps
• CPC Class Codes: G02B 6/02357 Property of longitudinal structures or background material varies radially and/or azimuthally in the cladding, e.g. size, spacing, periodicity, shape, refractive index, graded index, quasiperiodic, quasicrystals
• CPC Class Codes: G02B 6/02361 Longitudinal structures forming multiple layers around the core, e.g. arranged in multiple rings with each ring having longitudinal elements at substantially the same radial distance from the core, having rotational symmetry about the fibre axis
• CPC Class Codes: G02B 6/02371 Cross section of longitudinal structures is non-circular
• CPC Class Codes: G02B 6/024 with polarisation maintaining properties
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence

Abstract

A composite polymer fiber comprises a polymer filler material and a plurality of polymer scattering fibers disposed within the filler material. At least one of the filler material and the scattering fibers is formed of a birefringent material. The refractive indices of the filler material and the scattering fibers can be substantially matched for light incident in a first polarization state on the composite polymer fiber and unmatched for light incident in an orthogonal polarization state. The scattering fibers may be arranged to form a photonic crystal within the composite fiber. The composite fibers may be extruded and may be formed into a yarn, a weave or the like. If the filler material is soluble, it may be washed out of the yarn or weave, and the scattering fibers may then be infiltrated with a resin that is subsequently cured.

Claims

1. An optical body, comprising:

a polymer matrix; and

a plurality of polymer composite fibers disposed within the polymer matrix, at least one of the polymer composite fibers comprising a plurality of scattering fibers of a first polymer material within a filler of a second polymer material different from the first polymer material, the polymer composite fibers being arranged substantially parallel in the polymer matrix, at least one of the polymer matrix, the first polymer material and the second polymer material being birefringent.

2. An optical body as recited in claim 1, wherein at least one of the first and second polymer materials is birefringent.

3. An optical body as recited in claim 1, wherein the polymer matrix comprises one of the first polymer material and the second polymer material.

4. An optical body as recited in claim 1, wherein the polymer matrix comprises a matrix material different from the first and second polymer materials.

5. An optical body as recited in claim 1, wherein at least one of the scattering fibers comprises a disperse phase scattering fiber comprising a disperse phase in a continuous phase.

6. An optical body as recited in claim 1, further comprising a fiber weave disposed within the polymer matrix, the fiber weave comprising the plurality of polymer composite fibers.

7. An optical body as recited in claim 6, wherein the plurality of polymer fibers comprise one of the warp and the weft of the fiber weave.

8. An optical body as recited in claim 7, wherein the other of the warp and the weft of the fiber weave comprises at least one of optically isotropic polymer fibers, optically isotropic natural fibers, glass fibers, glass-ceramic fibers and ceramic fibers.

9. An optical body as recited in claim 7, wherein the other of the warp and the weft of the fiber weave comprises isotropic fibers having a refractive index substantially similar to the refractive index of the polymer matrix.

10. An optical body as recited in claim 1, wherein the composite fibers of the plurality of composite fibers are arranged in a random pattern in a cross-section through the polymer matrix.

11. An optical body as recited in claim 1, wherein the polymer matrix is formed as a layer having at least one structured surface.

12. An optical body as recited in claim 11, wherein the at least one structured surface comprises an array of prismatic structures.

13. A method of producing an optical body, comprising:

extruding composite fibers, each composite fiber containing a plurality of scattering fibers, made of a first polymer, dispersed in a filler, made of a second polymer, the second polymer being soluble;

orienting the first polymer so that the first polymer becomes birefringent;

forming a yarn containing the oriented composite fibers;

washing the yarn in a solvent to remove the second polymer;

forming an array of yarn where the array of yarn has a preferred orientation;

saturating the array of yarn with a resin; and

hardening the resin.

14. The method for producing the optical body recited in claim 13, further comprising orienting the first polymer before forming the yarn.

15. The method for producing the optical body recited in claim 13, further comprising orienting the first polymer after forming the yarn.

16. A method of producing an optical body, comprising:

extruding composite fibers, each composite fiber containing a plurality of scattering fibers, made of a first polymer, dispersed in a filler, made of a second polymer, at least one of the first and second polymers being orientable;

arranging the composite fibers together; and

fusing the composite fibers to form a fused optical body.

17. The method as recited in claim 16, further stretching the composite fibers to as to orient the at least one of the first and second polymers that is orientable.

18. The method as recited in claim 16, further comprising stretching the composite fibers before fusing the composite fibers.

19. The method as recited in claim 16, further comprising stretching the composite fibers after fusing the composite fibers.

20. The method as recited in claim 16, wherein arranging the composite fibers together comprises arranging the composite fibers to be substantially parallel to each other.

21. The method as recited in claim 16, wherein arranging the composite fibers together comprises forming the composite fibers into at least one tow.

22. The method as recited in claim 16, wherein arranging the composite fibers together comprises forming the composite fibers into at least one fiber weave.