Expandable bladders as tooling for composite parts

Patent metadata

Field	Value
Publication number	US-11426951-B2
Application number	US-201916237912-A
Country	US
Kind code	B2
Filing date	Jan 2, 2019
Priority date	Jan 2, 2019
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

Systems and methods are provided for utilizing pellet-loaded bladders to consolidate and/or harden composite parts. One embodiment is a method for fabricating a composite part. The method includes laying up a preform that is made of fiber reinforced material and that includes a cavity, inserting one or more bladders that are loaded with expandable pellets into the cavity, inflating the bladders in response to a triggering condition, consolidating the preform while the bladders are inflated, deflating the bladders, and removing the bladders from the cavity.

First claim

What is claimed is:

1. A method for fabricating a composite part, the method comprising:
laying up a preform that is made of fiber reinforced material and that includes a cavity;
inserting one or more bladders that are loaded with expandable pellets into the cavity;
inserting filler pellets into the cavity that are external to the one or more bladders;
inflating the one or more bladders in response to a triggering condition that increases volumes of the expandable pellets and causes the pellets to force flexible casings of the one or more bladders outward;
consolidating the preform while the one or more bladders are inflated;
deflating the one or more bladders by cooling the one or more bladders; and
removing the one or more bladders from the cavity.

2. The method of claim 1 further comprising:
hardening the preform into a composite part while the one or more bladders are inflated.

3. The method of claim 1 further comprising:
increasing volumes of the expandable pellets is performed via a foaming agent within the pellets, wherein:
inflation of the one or more bladders is caused by the volumes of the pellets increasing, and wherein:
deflating the one or more bladders comprises cooling the expandable pellets below a foaming temperature of the foaming agent.

4. The method of claim 1 wherein:
the filler pellets comprise additional expandable pellets.

5. The method of claim 1 further comprising:
inserting an additional bladder that is loaded with additional expandable pellets into the cavity.

6. The method of claim 1 further comprising:
arranging the one or more bladders within the cavity based on a cross-sectional shape of the cavity.

7. The method of claim 1 further comprising:
selecting shapes of the one or more bladders based on a cross-sectional shape of the cavity.

8. The method of claim 1 further comprising:
laying the preform up against a mandrel prior to inflating the one or more bladders.

9. The method of claim 1 wherein:
increasing the volumes of the pellets via releasing gas by triggering a foaming agent.

10. The method of claim 1 wherein:
the triggering condition is selected from the group consisting of: temperature triggered reactions, depressurization, ultraviolet triggered chemical reactions, and mixing of additional parts.

11. The method of claim 1 further comprising:
hardening the preform to form a portion of an aircraft.

12. The method of claim 1 wherein:
laying up the preform that is made of fiber reinforced material comprises laying up a preform that is made of Carbon Fiber Reinforced Polymer (CFRP).

13. The method of claim 1 wherein:
inserting the one or more bladders that are loaded with expandable pellets comprises inserting one or more bladders that are loaded with pellets that each comprise a matrix of flexible material having airtight pockets.

14. The method of claim 1 wherein:
inflating the one or more bladders comprises activating a foaming agent.

15. The method of claim 14 wherein:
activating the foaming agent causes the expandable pellets increase in size.

16. The method of claim 1 wherein:
inflating the one or more bladders applies forces to an elastically deformable material of the flexible casings of the one or more bladders.

17. The method of claim 1 wherein:
deflating the one or more bladders comprises piercing the one or more bladders.

18. The method of claim 1 wherein:
deflating the one or more bladders comprises operating a port at the one or more bladders.

19. The method of claim 1 further comprising:
including one or more bars of rigid material within the one or more bladders.

20. The method of claim 19 wherein:
including the one or more bars of rigid material comprises inserting one or more bars that are hollow.

21. A non-transitory computer readable medium embodying programmed instructions which, when executed by a processor, are operable for performing a method for fabricating a composite part, the method comprising:
laying up a preform that is made of fiber reinforced material and that includes a cavity;
inserting one or more bladders that are loaded with expandable pellets into the cavity;
inserting filler pellets into the cavity that are external to the one or more bladders;
inflating the one or more bladders in response to a triggering condition that increases volumes of the expandable pellets and causes the pellets to force flexible casings of the one or more bladders outward;
consolidating the preform while the one or more bladders are inflated;
deflating the one or more bladders by cooling the one or more bladders; and
removing the one or more bladders from the cavity.

22. The non-transitory computer readable medium of claim 21 wherein:
the method further comprises hardening the preform to form a portion of an aircraft.

Assignees

• Boeing Co

Inventors

• Wang Xiaoxi
• Georgeson Gary E

Classifications

• B29C2043/3652

  Elastic moulds or mould parts, e.g. cores or inserts · CPC title

• B29L2022/00

  Hollow articles (tubular articles B29L2023/00; pneumatic tyres B29L2030/00) · CPC title

• B29C2043/3657

  additional materials, e.g. permeable bleeder or breather sheets, cloths, blankets · CPC title

• B29C70/54 Primary

  Component parts, details or accessories; Auxiliary operations {, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing} · CPC title

• B29K2105/06

  containing reinforcements, fillers or inserts · CPC title