Large-area fiber composite with high fiber consistency

• US 20020011300A1
• Filed: 04/12/2001
• Published: 01/31/2002
• Est. Priority Date: 04/12/2000
• Status: Active Grant

• Current Assignee: Richard B. Cass
• Original Assignee: Richard B. Cass
• Inventors: Cass, Richard B.
• Granted Patent: US 6,620,287 B2
• Time in Patent Office: Days
• US Class Current: 156/89.12
• CPC Class Codes: B29C 70/20 oriented in a single direction, e.g. roofing or other parallel fibres B29C70/083, B29C70/226 take precedence
• CPC Class Codes: B29K 2995/0003 having particular electrical or magnetic properties, e.g. piezoelectric
• CPC Class Codes: B29L 2031/3061 Number plates
• CPC Class Codes: B29L 2031/3456 Antennas, e.g. radomes
• CPC Class Codes: B29L 2031/3468 Batteries, accumulators or fuel cells battery cases B29L2031/7146
• CPC Class Codes: H10N 30/092 Forming composite materials
• CPC Class Codes: H10N 30/1061 based on piezoelectric or electrostrictive fibres
• CPC Class Codes: H10N 30/852 Composite materials, e.g. having 1-3 or 2-2 type connectivity
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling

Abstract

A method of manufacturing a fiber assembly, the method comprising: (a) providing a plurality of layers, each layer comprising sintered fibers of piezoelectric material aligned substantially parallel; (b) laminating the plurality of layers; and (c) applying a matrix material to the laminated layers to affix the layers and form a fiber assembly.

Claims

1. A method of manufacturing a fiber assembly, said method comprising:

providing a plurality of layers, each layer comprising sintered fibers of piezoelectric material aligned substantially parallel;

laminating said plurality of layers; and

applying a matrix material to the laminated layers to affix said layers and form a fiber assembly.

2. The method of claim 1, further comprising:

sectioning a portion from said fiber assembly.

3. The method of claim 2, wherein said portion has two opposing surfaces and contains fibers that are substantially normal to said opposing surfaces.

4. The method of claim 2, wherein said portion has two opposing surfaces and contains fiber that are substantially parallel to said opposing surfaces.

5. The method of claim 2, further comprising:

applying at least one electrode to each opposing surface.

6. The method of claim 5, wherein a plurality of interigitized electrodes are applied.

7. The method of claim 1, wherein laminating said planar layers comprises interleaving planar layers of varying fiber characteristics.

8. The method of claim 7, wherein said layers of varying fiber characteristics have different fiber concentrations.

9. The method of claim 7, wherein said layers of varying fiber characteristics have fibers of different average diameters.

10. The method of claim 7, wherein a different set of electrodes is applied to said layers of varying fiber characteristics.

11. The method of claim 1, wherein said layers have substantially similar fiber characteristics.

12. The method of claim 1, further comprising poling said sectioned portion.

14. The method of claim 1, wherein each opposing side of said portion has an area greater than about 1.5 cm².

15. The method of claim 1, wherein the variation of fiber concentration in no greater than about 20%/cm³.

16. A fiber assembly made from the method of claim 1.

17. A portion made from the method of claim 2.

13. The method of claim , wherein said piezoelectric material is at least one of PZT (lead zirconium titanate), lead niobate (PbNbO₆), lead titanate (PbTiO₃), barium titanate (BaTiO₃), sodium bismoth titanate (pure or co-doped), lead-based ceramics doped with lanthanum, tin, or niobium, electrostrictive materials, memory piezoelectric materials, or relaxor materials.

18. A fiber composite comprising:

two opposing surfaces wherein each opposing surface has an area greater than about 1.5 in²;

a plurality of piezoelectric fibers wherein the fiber concentration/cm³ varies no greater than about 20% of the overall fiber concentration of fiber composite; and

a matrix material binding said fibers.

19. The fiber composite of claim 18, wherein said fibers are normal to said opposing surfaces.

20. The fiber composite of claim 18, wherein said area is no less than about 2.5 in²