Controlled fiber-matrix adhesion in polymer fiber composites

Patent metadata

Field	Value
Publication number	US-9857148-B2
Application number	US-96851410-A
Country	US
Kind code	B2
Filing date	Dec 15, 2010
Priority date	Dec 15, 2010
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A composite article includes a plurality of fibers at least partially embedded within a matrix. The fibers may be adhered to the matrix at a level of adhesion. The adhesion level between the fibers and the matrix may be varied spatially within the composite article. For example, the adhesion level may vary along a length of one of the fibers. The adhesion level may also vary among the fibers of a given layer. Furthermore, the adhesion level may vary between the layers of the composite article.

First claim

What is claimed is:

1. A composite article, comprising:
a plurality of fibers at least partially embedded within a matrix and forming a plurality of layers arranged in a layer stack of the composite article;
the fibers in one of the layers being oriented at an angle that is different than the fibers in another one of the layers;
the fibers adhering to the matrix at a level of adhesion;
at least one of the layers having fibers oriented parallel to one another and arranged in a plurality of fiber groups, each fiber group including a plurality of adjacent fibers;
wherein the fibers in at least one of the fiber groups in a layer have:
an adhesion level along a lengthwise portion of the fibers of the fiber group being greater than the adhesion level along an entire length of the fibers of another fiber group in the same layer; and
the adhesion level along the lengthwise portion of the fibers of the fiber group being less than the adhesion level at another lengthwise portion of the same fiber group.

2. The composite article of claim 1 wherein the adhesion level along the length of at least one of the fibers in at least one of the layers varies in at least one of the following manners:
generally uniform increases and decreases in adhesion levels along the fiber length;
gradual increases and decreases in adhesion levels along the fiber length;
sinusoidally changing increases and decreases in adhesion levels along the fiber length.

3. The composite article of claim 1 wherein:
at least a portion of one of the fibers having a release agent reducing the adhesion level of the fiber.

4. The composite article of claim 1 wherein:
at least a portion of one of the fibers having a bonding agent increasing the adhesion level of the fiber.

5. The composite article of claim 1 wherein:
at least a portion of one of the fibers having a different surface roughness relative to a remaining portion of the fiber and resulting in a higher adhesion level.

6. The composite article of claim 1 wherein:
the fiber comprises a substantially optically transparent fiber;
the matrix comprises a substantially optically transparent polymeric matrix; and
the fiber and the matrix define an interface being substantially optically transparent.

7. The composite article of claim 1 wherein at least one of the matrix and the fiber is formed from at least one of the following:
a thermoplastic material comprising at least one of the following: fluorocarbons, polyamides, polyethylenes, polyesters, polypropylenes, polycarbonates, polyurethanes, polyetheretherketone, polyetherketoneketone;
a thermoset comprising at least one of the following: polyurethanes, phenolics, polyimides, bismaleimides, polyesters, epoxy; and
glass.

8. The composite article of claim 1 wherein:
the adhesion level progressively increases and/or changes in a stepwise manner across the layer stack from the outermost layer on one side of the layer stack to the outermost layer on the opposite side of the layer stack.

9. The composite article of claim 1 wherein:
the composite article is configured as a ballistic panel having a strike face and a back face;
the strike face configured to receive an impact from an object.

10. The composite article of claim 9 further including:
at least one additional layer formed of glass or ceramic and bonded to the strike face.

11. The composite article of claim 1 wherein:
one or more of the fibers has a different composition than the remaining fibers in the composite article;
the different composition of the one or more of the fibers resulting in a different adhesion level relative to the adhesion level of the remaining fibers.

12. The composite article of claim 1 wherein:
at least one pair of layers of the layer stack are bonded together with a low adhesion level relative to the adhesion level bonding the remaining layers of the layer stack.

13. A composite article, comprising:
a plurality of fibers at least partially embedded within a matrix and forming a plurality of layers arranged in a layer stack of the composite article;
the fibers in one of the layers being oriented at an angle that is different than the fibers in another one of the layers;
the fibers and the matrix adhering to one another and having adhesion properties of an adhesive bond at an interface between the fibers and the matrix;
the adhesion properties of the adhesive bond at the interface comprising at least one of stiffness, ductility, and strain-to-failure;
at least one of the layers having fibers oriented parallel to one another and arranged in a plurality of fiber groups, each group including a plurality of adjacent fibers;
wherein the fibers in at least one of the fiber in a layer have:
an adhesion property along a lengthwise portion of the fibers of the fiber group being greater than the adhesion property along an entire length of the fibers of another fiber group in the same layer; and
the adhesion property along the lengthwise portion of the fibers of the fiber group being less than the adhesion property at another lengthwise portion of the same fiber group.

14. A method of manufacturing a composite article, comprising the steps of:
providing a plurality of layers in a layer stack, each layer including a plurality of fibers at least partially embedded within a matrix and adhering to the matrix at a level of adhesion, the fibers in one of the layers being oriented at an angle that is different than the fibers in another one of the layers, at least one of the layers having fibers oriented parallel to one another and arranged in a plurality of fiber groups, each fiber group including a plurality of adjacent fibers;
providing an adhesion level along a lengthwise portion of the fibers of at least one of the fiber groups that is greater than the adhesion level along an entire length of the fibers of another fiber group in the same layer; and
providing the adhesion level along the lengthwise portion of the fibers of the at least one fiber group to be less than the adhesion level at another lengthwise portion of the same fiber group.

15. The method of claim 14 further including:
varying the adhesion level along the the lengthwise portion of at least one of the fibers in at least one of the layers in at least one of the following manners:
generally uniform increases and decreases in the adhesion level along the lengthwise portion;
gradual increases and decreases in the adhesion level along the lengthwise portion; and
sinusoidally changing increases and decreases in the adhesion level along the lengthwise portion.

16. The method of claim 14 wherein:
at least a portion of one of the fibers has a release agent decreasing the adhesion level of the fiber.

17. The method of claim 14 wherein:
at least a lengthwise portion of at least one of the fibers has a bonding agent increasing the adhesion level of the fiber.

18. The method of claim 14 wherein:
at least a lengthwise portion of at least one of the fibers has a different surface roughness relative to a remaining lengthwise portion of the at least one of the fibers and resulting in a higher adhesion level.

19. The method of claim 14 wherein:
the fibers comprise substantially optically transparent fibers;
the matrix comprises a substantially optically transparent polymeric matrix; and
the fibers and the matrix define an interface being substantially optically transparent.

20. The method of claim 14 wherein at least one of the matrix and the fibers is formed

Assignees

• Wilenski Mark S
• Kozar Michael P
• Boeing Co

Inventors

• Wilenski Mark S
• Kozar Michael P

Classifications

• Y02T50/433

  Cross-Sectional Technologies · mapped topic

• B32B5/26

  another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)} · CPC title

• B32B2260/023

  Two or more layers · CPC title

• Y10T428/249921

  Web or sheet containing structurally defined element or component · CPC title

• B32B2571/02

  defensive, e.g. armour plates or anti-ballistic clothing · CPC title