Composite polymer fibers

• US 7,356,231 B2
• Filed: 02/28/2005
• Issued: 04/08/2008
• 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., Benson, Olester Jr., Stumo, Roger J., Chou, Yeun-Jong, North, Diane
• Primary Examiner(s): KIANNI, KAVEH C
• Application Number:
  US11/068,158
• Publication Number:
  US 20060193582A1
• Time in Patent Office: 1,135 Days
• Field of Search: 385/123, 385/127, 385/11
• US Class Current: 385/123
• 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. A composite polymer fiber, comprising:

a polymer filler material; and

a plurality of polymer scattering fibers disposed within the filler material, the scattering fibers having longitudinal axes substantially parallel to a longitudinal axis of the composite polymer fiber;

wherein 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 being substantially matched for light incident in a first polarization state on the composite polymer fiber and being substantially unmatched for light incident in a second polarization state orthogonal to the first polarization state.

2. A composite fiber as recited in claim 1, wherein the fiber has a substantially circular cross-section.

3. A composite fiber as recited in claim 1, wherein the fiber has a substantially non-circular cross-section.

4. A composite fiber as recited in claim 1, wherein at least some of the scattering fibers have a substantially circular cross-section.

5. A composite fiber as recited in claim 1, wherein at least some of the scattering fibers have a substantially non-circular cross-section.

6. A composite fiber as recited in claim 1, wherein at least some of the scattering fibers are twisted together.

7. A composite fiber as recited in claim 1, wherein at least some of the scattering fibers are arranged irregularly across a cross-section of the composite fiber.

8. A composite fiber as recited in claim 1, wherein at least some of the scattering fibers are arranged regularly across a cross-section of the composite fiber.

9. A composite fiber as recited in claim 8, wherein at least some of the scattering fibers are arranged at locations of a regular grid pattern across the cross-section of the composite fiber, with at least one location of the regular grid pattern having no scattering fiber.

10. A composite fiber as recited in claim 8, wherein at least some of the scattering fibers are arranged within the composite fiber so that the arrangement of scattering fibers provides spectrally selective properties for light laterally incident on the composite fiber.

11. A composite fiber as recited in claim 1, further comprising cover layers surrounding respective scattering fibers.

12. A composite fiber as recited in claim 11, wherein the scattering fibers are formed of a scattering fiber material and the cover layer is formed of one of the filler material and the scattering fiber material.

13. A composite fiber as recited in claim 1, wherein at least one of the scattering fibers comprises a shell surrounding a core, the shell and core being formed of different materials.

14. A composite fiber as recited in claim 1, wherein at least one of the scattering fibers comprises a disperse phase of a first polymer material in a continuous phase of a second polymer material.