Consolidated composite pre-form

Patent metadata

Field	Value
Publication number	US-8986487-B2
Application number	US-98988909-A
Country	US
Kind code	B2
Filing date	Apr 29, 2009
Priority date	Apr 30, 2008
Publication date	Mar 24, 2015
Grant date	Mar 24, 2015

Abstract

The present invention relates to a consolidated composite pre-form for reinforcing a composite structure, said pre-form comprising fibers and a binding agent, said pre-form having a sheet-like structure with an upper major surface and a lower major surface, and said pre-form being provided with recesses on at least a portion of at least one of said major surfaces.

First claim

The invention claimed is:

1. A method of producing a pre-form, comprising:
providing a layer of a binding agent;
providing a fibre layer of fibres or fibre tows on the layer of a binding agent to produce a delimited longitudinal sheet-like pre-form of fibres and a binding agent, the pre-form having an upper major surface and a lower major surface;
applying a vacuum to consolidate the pre-form by removing air from the pre-form, and imprinting recesses into at least one of the major surfaces of the pre-form by application of pressure to the at least one of the major surfaces during the consolidation, the binding agent remaining uncured or only partially cured after consolidation, and
wherein at least one of the recesses extends at least from a longitudinal centreline to a longitudinal edge of the pre-form, and
wherein the uncured or only partially cured binding agent in the consolidated pre-form is adapted to enable additional bending and shaping of the pre-form during placement and fitting into a composite structure to be reinforced by the pre-form.

2. The method according to claim 1 , wherein the pre-form comprises at least two layers of fibres, separated by a layer of a binding agent.

3. The method according to claim 1 , wherein the fibres are impregnated with a binding agent.

4. The method according to claim 1 , wherein all of the recesses extend at least from the longitudinal centreline to the longitudinal edge of the pre-form.

5. The method according to claim 1 , wherein at least one of said recesses extends at an angle between 30 and 90 degrees in relation to the longitudinal centreline of the pre-form.

6. The method according to claim 1 , wherein at least one of said recesses is wider at the edge of the pre-form than at the centreline of the pre-form.

7. The method according to claim 1 , wherein said fibres comprise carbon fibres.

8. The method according to claim 1 , wherein the binding agent is a thermosetting resin.

9. The method according to claim 8 , wherein the thermosetting resin is an epoxy resin.

10. The method according to claim 1 , wherein the pre-form has a tapered shape.

11. The method according to claim 1 , wherein the imprinted recesses in the pre-form include a plurality of elongated channels separated and spaced apart from one another, with each of the elongated channels extending from an outer edge of the pre-form towards the longitudinal centreline.

12. The method according to claim 1 , wherein the pre-form is arranged on a mandrel together with additional fibres in order to form a composite laminate.

13. The method according to claim 1 , wherein binding agent is infused into the pre-form.

14. The method according to claim 1 , wherein the pre-form is heated during the consolidation.

15. The method according to claim 1 , further comprising:
fitting the pre-form into a composite structure to be reinforced, the pre-form being bent and shaped to match the composite structure; and
fully curing the binding agent in the pre-form, after fitting, at an elevated temperature.

16. The method according to claim 1 , wherein the binding agent of the pre-form is cured, after consolidation, at an elevated temperature of at least 100° C.

17. A method of producing a reinforced composite structure, comprising:
providing a first longitudinal reinforcing pre-form comprising fibres and a binding agent;
providing a second longitudinal reinforcing pre-form, comprising fibres and a binding agent, overlapping the first pre-form in an overlap area;
applying a vacuum to consolidate the first and second pre-forms and imprinting recesses into a major surface of at least one of the first and second pre-forms by application of pressure to the major surface during the consolidation, which recesses form channels in an interface between the first and second pre-forms in the overlap area, wherein at least one of the recesses extends at least between a longitudinal centreline and a longitudinal edge of the pre-form; and
applying a vacuum to consolidate the first and second pre-forms together to become the structure, such that air trapped between the first and second pre-forms in the overlap area may be evacuated from the overlap area through the channels, the binding agent in the first and second pre-forms remaining uncured or only partially cured after consolidation,
wherein the uncured or only partially cured binding agent in the first and second pre-forms is adapted to enable additional bending and shaping of the pre-forms during placement and fitting into the composite structure to be reinforced by the pre-forms.

18. The method according to claim 17 , further comprising providing additional pre-forms, forming further overlap areas comprising channels, before consolidating the structure.

19. The method according to claim 17 , wherein the first reinforcing pre-form is arranged on a mandrel together with additional fibres in order to form a composite laminate.

20. The method according to claim 17 , wherein binding agent is infused into the structure.

21. The method according to claim 17 , wherein the channels are arranged to collapse during the consolidation.

22. The method according to claim 17 , wherein the structure is heated during the consolidation.

23. The method according to claim 17 , further comprising:
fitting the first and second pre-forms into the composite structure to be reinforced, the first and second pre-forms being bent and shaped to match the composite structure; and
fully curing the binding agent in the first and second pre-forms, after fitting, at an elevated temperature.

24. The method according to claim 17 , wherein the binding agent of the structure is cured, after consolidation, at an elevated temperature of at least 100° C.

25. The method according to claim 17 , wherein the second longitudinal reinforcing pre-form partially overlaps the first pre-form in the overlap area.

Assignees

• Stenbaek Nielsen Knud
• Schroder Henning
• Vestas Wind Sys As

Inventors

• Stenbaek Nielsen Knud
• Schroder Henning

Classifications

• Y10T156/10

  Methods of surface bonding and/or assembly therefor · CPC title

• Y10T156/107

  Punching and bonding pressure application by punch · CPC title

• B29C70/547

  using channels or porous distribution layers incorporated in or associated with the product · CPC title

• B29C70/342 Primary

  using isostatic pressure · CPC title

• Y10T428/2457

  Parallel ribs and/or grooves · CPC title