Method of moulding a charge

Patent metadata

Field	Value
Publication number	US-10016949-B2
Application number	US-73344308-A
Country	US
Kind code	B2
Filing date	Sep 29, 2008
Priority date	Oct 4, 2007
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A method of molding a charge ( 12 ) during the manufacture of a composite part. The method comprises: placing the charge and a diaphragm ( 4 ) on a male tool, the charge having a first part ( 12 a ) which is positioned above a top of the male tool ( 2 ) and a second part ( 12 b, 12 c ) which projects to one side of the maletool; and progressively deforming the second part of the charge against a side of the male tool by applying a pressure difference across the diaphragm and stretching the diaphragm over the male tool as the pressure difference is applied. The diaphragm has a tensile modulus in the plane of the diaphragm which is greater than 5 MPa. Optionally a support membrane may be positioned on a opposite sides of the charge. In the case where a support membrane is used, then the diaphragm has a stiffness in the planeof the diaphragm which is higher than the stiffness of the support membrane in the plane of the support membrane.

First claim

The invention claimed is:

1. A method of moulding a charge during the manufacture of a composite part, the method comprising:
placing the charge, a support membrane, and a diaphragm on a male tool having at least one convex corner between a top of said mold and at least one side of said mold, the support membrane and diaphragm being positioned on opposite sides of the charge, the charge having a first part which is positioned above said top of the male tool and a second part which projects to said at least one side of the male tool;
supporting the weight of the second part of the charge with the support membrane;
placing the diaphragm in tension, wherein the diaphragm is under tension while the support membrane supports the weight of the second part of the charge and before a vacuum is applied;
applying the vacuum between the support membrane and the diaphragm;
stretching the diaphragm over the top of the male tool as the vacuum is applied, and
progressively deforming the support membrane and the second part of the charge against said at least one side of the male tool by applying a pressure difference across the diaphragm and stretching the diaphragm over the male tool as the pressure difference is applied, wherein the diaphragm has a stiffness in the plane of the diaphragm which is higher than the stiffness of the support membrane in the plane of the support membrane.

2. The method of claim 1 wherein the charge comprises a stack of plies of composite material.

3. The method of claim 2 wherein each ply contains a set of fibres which are substantially aligned with each other.

4. The method of claim 1 wherein the diaphragm is stretched over the male tool by bridging it over a channel next to the male tool whereby the pressure difference draws the diaphragm into the channel.

5. The method of claim 1 further comprising removing the deformed charge from the male tool; and curing it on a female tool.

6. The method of claim 1 wherein the top of the male tool meets the side of the male tool at said convex corner, said corner having a relatively high curvature.

7. The method of claim 1 wherein the diaphragm has a tensile modulus in the plane of the diaphragm which is greater than 6 MPa.

8. The method of claim 1 wherein the diaphragm has a tensile modulus in the plane of the diaphragm which is greater than 7 MPa.

9. The method of claim 1 wherein the diaphragm has a tensile modulus in the plane of the diaphragm which is greater than 8 MPa.

10. The method of claim 1 wherein the diaphragm is a multi-layer diaphragm.

11. A composite part manufactured by the method of claim 1 .

12. The composite part of claim 11 , wherein the composite part is an aircraft part.

13. The method of claim 1 wherein the diaphragm comprises two diaphragm layers, and the two diaphragm layers are each laid up in tension prior to the vacuum being applied.

14. The method of claim 1 wherein the diaphragm comprises a first diaphragm layer and a second diaphragm layer, and the first diaphragm layer and the second diaphragm layer have different stiffnesses.

15. The method of claim 14 wherein the second diaphragm layer is laid up on top of the first diaphragm layer, and the stiffness of the first diaphragm layer is greater than the stiffness of the second diaphragm layer.

16. The method of claim 1 further comprising placing a caul plate between the charge and the diaphragm.

17. The method of claim 1 wherein the male tool is mounted on a table; applying the pressure difference across the diaphragm comprises applying a vacuum between the support membrane and the table; the diaphragm is laid up in tension prior to the vacuum between the support membrane and the diaphragm being applied; and the diaphragm is laid up in tension prior to the vacuum between the support membrane and the table being applied.

18. The method of claim 1 further comprising placing the diaphragm over edge bars arranged on opposite sides of the male tool prior to the application of the vacuum, wherein the diaphragm is stretched due to the diaphragm bridging between the edge bars.

19. The method of claim 1 wherein the stretching of the diaphragm occurs at least partially prior to the application of the vacuum.

20. The method of claim 19 wherein the stretching of the diaphragm prior to the application of the vacuum is caused by the diaphragm bridging over the male tool by being supported on support structures on opposite sides of the male tool.

Assignees

• Pridie Jago
• Airbus Operations Ltd

Inventors

• Pridie Jago

Classifications

• B29C70/542

  Placing or positioning the reinforcement in a covering or packaging element before or during moulding, e.g. drawing in a sleeve · CPC title

• Y10T428/24132

  including grain, strips, or filamentary elements in different layers or components parallel · CPC title

• B29C2043/3644

  Vacuum bags; Details thereof, e.g. fixing or clamping · CPC title

• B29C43/3642

  Bags, bleeder sheets or cauls for isostatic pressing · CPC title

• B29C70/44 Primary

  using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding · CPC title