Composite materials

Patent metadata

Field	Value
Publication number	US-10688752-B2
Application number	US-201816047779-A
Country	US
Kind code	B2
Filing date	Jul 27, 2018
Priority date	Feb 2, 2004
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

Light weight composites with high flexural strength comprise epoxy foam sandwiched between two layers of facing material have high strength and low weight and can be used to replace steel structures. The facing layer may be fibrous material especially glass or carbon fibres, the facing material is preferably embedded into the epoxy matrix. Alternatively they may be matching box structures or concentric metal tubes. The sandwich structures may be prepared by laying up the fibre; coating and/or impregnating the layer with epoxy resin, laying a layer of heat activatable foamable epoxy material, providing a further layer of the fibrous material optionally coated and/or impregnated with epoxy resin on the foamable material and heating to foam and cure the epoxy materials. Alternatively they may be formed by extrusion of the foamable material between the surface layers.

First claim

The invention claimed is:

1. A composite comprising a sandwich structure comprising at least two carbon fiber surface layers attached to a central layer of rigid foam including a thermosetting epoxy resin, a thermoplastic resin additive and a polymerizable monomer wherein the layer of foam is at least 1.5 times the combined thickness of the two surface layers and the composite has a density of from 0.1 to 2.0 gram/cc.

2. A composite according to claim 1 in which the foam has a density of between 0.2 and 1.5 gram/cc.

3. A composite according to claim 1 in which the foam has a density of 0.3 to 0.6 gram/cc.

4. A composite according to claim 1 , wherein the at least two surface layers each have a thickness of from 0.2 to 10 millimeters and the layer of foam having a thickness of from 2 to 200 millimeters.

5. A composite according to claim 4 , in which the foam has a density of between 0.2 and 1.5 gram/cc.

6. A composite according to claim 4 , wherein the at least two surface layers each have a thickness of from 0.2 to 10 millimeters and the layer of foam having a thickness of from 2 to 200 millimeters.

7. A composite according to claim 4 , in which the composite includes inserts or layers selected from metal foil such as aluminum or steel foil, plastic film or sheeting such as polypropylene or polyethylene film or polyethylene terephthalate film.

8. A composite according to claim 1 , having a flexural modulus as measured by ASTM D790/ISO 178 from 200 mPa to 700 mPa.

9. A composite according to claim 8 in which the surface layers are fibrous and porous.

10. A composite according to claim 1 , in which the composite includes inserts or layers selected from metal foil such as aluminum or steel foil, plastic film or sheeting such as polypropylene or polyethylene film or polyethylene terephthalate film.

11. A composite according to claim 10 , in which the foam has a density of between 0.2 and 1.5 gram/cc.

12. A composite according to claim 10 , wherein the at least two surface layers each have a thickness of from 0.2 to 10 millimeters and the layer of foam having a thickness of from 2 to 200 millimeters.

13. A composite according to claim 1 , in which the surface layers are porous.

14. A composite according to claim 1 , in which the surface layers are matching internal and external structures.

15. A composite according to claim 14 , in which the foam has a density of between 0.2 and 1.5 gram/cc.

16. A composite according to claim 14 , wherein the at least two surface layers each have a thickness of from 0.2 to 10 millimeters and the layer of foam having a thickness of from 2 to 200 millimeters.

17. A composite according to claim 14 , in which the composite includes inserts or layers selected from metal foil such as aluminum or steel foil, plastic film or sheeting such as polypropylene or polyethylene film or polyethylene terephthalate film.

18. A composite according to claim 1 , in which the composites form hollow box sections.

19. A composite according to claim 1 , in which the composites form tubes.

20. A composite according to claim 1 , wherein the polymerizable monomer comprises a methacrylate based material.

Assignees

• Zephyros Inc

Inventors

• Le Gall Eric
• Ostrowsky Frederic
• Souvay Denis

Classifications

• B32B2038/0084

  Foaming · CPC title

• B29C44/1228

  Joining preformed parts by the expanding material · CPC title

• B32B5/245

  another layer next to it being a foam layer · CPC title

• B32B2607/00

  Walls, panels · CPC title

• B32B5/18 Primary

  characterised by features of a layer {of} foamed material · CPC title