Composite fabrication system with alternating air pressure control

Patent metadata

Field	Value
Publication number	US-11660828-B2
Application number	US-201816056766-A
Country	US
Kind code	B2
Filing date	Aug 7, 2018
Priority date	Aug 7, 2018
Publication date	May 30, 2023
Grant date	May 30, 2023

Abstract

A method and system for fabricating a composite structure is provided. A first vacuum bag is laid down on a surface of a tool. A composite material is positioned on top of the first vacuum bag on the tool. A second vacuum bag covers the composite material. Vacuum pressure is applied to the first vacuum bag and the second vacuum bag. The composite material is cured to form the composite structure. The first vacuum bag is inflated with compressed air to lift the composite structure from the tool.

First claim

What is claimed is:

1. A method for fabricating a composite structure, the method comprising:
laying down a first vacuum bag on a surface of a tool;
positioning a composite material on top of the first vacuum bag on the tool;
covering the composite material with a second vacuum bag;
applying a first vacuum pressure to the first vacuum bag through a first supply line;
applying a second vacuum pressure to the second vacuum bag through a second supply line to form the composite material to a shape of the tool before curing the composite material;
curing the composite material to form the composite structure; and
inflating the first vacuum bag with compressed air through the first supply line and releasing the second vacuum pressure through the second supply line to form a gap between the first vacuum bag and the second vacuum bag and to create a space between the first vacuum bag and the tool, wherein the compressed air in the space lifts the composite structure from the tool.

2. The method of claim 1 , wherein the composite material comprises a composite preform and a resin, and further comprising:
positioning a composite preform on top of the first vacuum bag on the tool; and
infusing the composite preform with the resin prior to curing.

3. The method of claim 2 further comprising:
switching an air pressure control system associated with the first vacuum bag from the first vacuum pressure to the compressed air.

4. The method of claim 1 further comprising:
removing the composite structure from the tool.

5. The method of claim 1 , wherein inflating the first vacuum bag with the compressed air lifts a web of the composite structure along a length of the composite structure.

6. The method of claim 5 , wherein inflating the first vacuum bag with the compressed air comprises:
inflating the first vacuum bag at a desired rate along the length of the composite structure.

7. The method of claim 6 further comprising:
determining a desired pressure for the compressed air corresponding to the desired rate for inflating the first vacuum bag.

8. The method of claim 1 further comprising:
filling a cavity between the tool and the first vacuum bag with the compressed air before the compressed air in the space lifts the composite structure from the tool.

9. A method for fabricating a composite structure for an aircraft, the method comprising:
laying down a first vacuum bag on a surface of a tool;
positioning a composite preform on top of the first vacuum bag on the tool;
covering the composite preform with a second vacuum bag;
infusing the composite preform with resin;
applying a first vacuum pressure to the first vacuum bag through a first supply line and a second vacuum pressure to the second vacuum bag through a second supply line to form the composite preform to a shape of the tool before curing the composite preform;
curing the composite preform and the resin to form the composite structure; and
inflating the first vacuum bag with compressed air through the first supply line and releasing the second vacuum pressure through the second supply line forming a gap between the first vacuum bag and the second vacuum bag and creating a space between the first vacuum bag and the tool, wherein the compressed air in the space lifts the composite structure from the tool.

10. The method of claim 9 further comprising:
switching an air pressure control system from the first vacuum pressure to the compressed air.

11. The method of claim 9 further comprising:
removing the composite structure from the tool.

12. The method of claim 9 , wherein inflating the first vacuum bag with the compressed air lifts a web of the composite structure along a length of the composite structure.

13. The method of claim 12 , wherein inflating the first vacuum bag with the compressed air comprises:
inflating the first vacuum bag at a desired rate along the length of the composite structure.

14. The method of claim 13 further comprising:
determining a desired pressure for the compressed air corresponding to the desired rate of inflating the first vacuum bag.

15. The method of claim 9 further comprising:
releasing the second vacuum pressure in the second vacuum bag as the first vacuum bag inflates.

16. The method of claim 9 , wherein the composite preform is infused with the resin prior to curing.

17. The method of claim 9 , further comprising:
filling a cavity between the tool and the first vacuum bag with the compressed air before the compressed air in the space lifts the composite structure from the tool.

18. The method of claim 9 , further comprising:
switching an air pressure control system associated with the first vacuum bag from the first vacuum pressure to the compressed air.

19. The method of claim 1 further comprising:
releasing the second vacuum pressure in the second vacuum bag as the first vacuum bag inflates.

20. The method of claim 1 , further comprising:
switching an air pressure control system associated with the first vacuum bag from the first vacuum pressure to the compressed air.

Assignees

• Boeing Co

Inventors

• Dostal Juergen

Classifications

• B29C70/541

  Positioning reinforcements in a mould, e.g. using clamping means for the reinforcement (positioning inserts in moulds B29C33/12; lay-up on a mould B29C70/30) · CPC title

• B29C51/00

  Shaping by thermoforming {, i.e. shaping sheets or sheet like preforms after heating}, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor {(blow moulding of tubular preforms B29C49/00, deforming of tubular or hollow preforms B29C67/0014)} · CPC title

• B29C37/0003 Primary

  Discharging moulded articles from the mould (constructions for removing the articles B29C33/44) · CPC title

• B29C2043/5053

  using pressurised gas, e.g. air · CPC title

• 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