Magnetic compaction blanket for composite structure curing

• US 9,403,328 B1
• Filed: 02/08/2013
• Issued: 08/02/2016
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Hafenrichter, Joseph Lawrence, Hull, John Ralph
• Primary Examiner(s): Gupta, Yogendra
• Assistant Examiner(s): Stewart, Kimberly A
• Application Number:
  US13/762,930
• Time in Patent Office: 1,271 Days
• Field of Search: 264/480
• US Class Current: 1/1
• CPC Class Codes: B25B 11/002 Magnetic work holders
• CPC Class Codes: B29C 37/0075 using release sheets
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/785 using magnetic forces to hold at least one of the parts to be joined magnetic work holders in general B25B11/002
• CPC Class Codes: B29C 73/10 using patches sealing on the surface of the article B29C73/14 takes precedence
• CPC Class Codes: B29C 73/12 Apparatus therefor, e.g. for applying B29C73/30 takes precedence
• CPC Class Codes: B29C 73/30 for local pressing or local heating
• CPC Class Codes: B29L 2031/3076 Aircrafts blades, propellers B29L2031/08
• CPC Class Codes: B32B 2037/1081 using a magnetic force
• CPC Class Codes: B32B 7/025 Electric or magnetic properties
• CPC Class Codes: F16B 2200/83 Use of a magnetic material

Abstract

A method and apparatus for reworking a structure. A compaction blanket comprising a number of magnets is placed on the structure. A heat source is applied on the compaction blanket, wherein the compaction blanket is between the heat source and a rework of the structure and heat is conducted from the heat source through the compaction blanket to heat the rework.

Claims

1. A method for reworking a structure, comprising:

placing a compaction blanket comprising a number of magnets on a first side of the structure;

placing a magnetic compaction structure on a second side of the structure, wherein a rework is between the compaction blanket and the magnetic compaction structure, and wherein magnetic attraction between the compaction blanket and the magnetic compaction structure pulls the compaction blanket and the magnetic compaction structure toward each other to compact the rework between the compaction blanket and the magnetic compaction structure; and

applying a heat source on the compaction blanket, wherein the compaction blanket is between the heat source and the rework of the structure and heat is conducted from the heat source through the compaction blanket to heat the rework.

2. The method of claim 1, wherein the heat is to cure the rework.

3. The method of claim 1, wherein the number of magnets are selected from the group of permanent magnets consisting of rare-earth magnets, iron-boron neodymium magnets, samarium cobalt magnets, and ferrite magnets.

4. The method of claim 1, wherein the compaction blanket comprises the number of magnets attached to a magnetic backplane.

5. The method of claim 4, wherein the magnetic backplane comprises a material selected from the group of magnetic materials comprising a metal sheet, a ferromagnetic metal sheet with slits therein, a metal mesh, steel shot, and ferromagnetic powder.

6. The method of claim 1, wherein the compaction blanket comprises the number of magnets encapsulated in a non-magnetic material.

7. The method of claim 6, wherein the non-magnetic material is flexible and wherein placing the compaction blanket comprises:

placing the compaction blanket on a magnetic holder tool;

placing the compaction blanket on the structure with the magnetic compaction blanket on the magnetic holder tool; and

removing the magnetic holder tool from the compaction blanket after placing the compaction blanket on the structure.

8. The method of claim 1, wherein the compaction blanket is a first magnetic compaction blanket and the number of magnets is a first number of magnets and wherein the magnetic compaction structure is selected from a metal sheet, a metal mesh, and a second magnetic compaction blanket comprising a second number of magnets.

9. The method of claim 1, wherein the heat source is selected from a heat blanket placed on the compaction blanket and a heated gas.

10. The method of claim 1, wherein the heat source is a heat blanket placed on the compaction blanket and further comprising applying a compression to the heat blanket, wherein the heat blanket is between the compression and the compaction blanket.

11. The method of claim 10, wherein the compaction blanket is a first magnetic compaction blanket and the number of magnets is a first number of magnets and wherein applying the compression to the heat blanket is selected from:

placing a magnetic sheet such that the heat blanket is between the magnetic sheet and the first magnetic compaction blanket and magnetic attraction between the magnetic sheet and the first magnetic compaction blanket pulls the magnetic sheet toward the first magnetic compaction blanket to compress the heat blanket between the magnetic sheet and the first magnetic compaction blanket;

placing compression wrap such that the heat blanket is between the compression wrap and the first magnetic compaction blanket; and

placing a second magnetic compaction blanket comprising a second number of magnets such that the heat blanket is between the second magnetic compaction blanket and the first magnetic compaction blanket and the magnetic attraction between the second magnetic compaction blanket and the first magnetic compaction blanket pulls the second magnetic compaction blanket toward the first magnetic compaction blanket to compress the heat blanket between the second magnetic compaction blanket and the first magnetic compaction blanket.

12. The method of claim 1, wherein the structure is a structure on an aircraft.

13. The method of claim 1, wherein the structure is a composite structure.

14. The method of claim 13, wherein the heat is to cure the rework on the composite structure.

15. The method of claim 13, wherein the structure is a composite structure on an aircraft.

16. A method for reworking a structure, comprising:

placing a first magnetic compaction blanket comprising a first number of magnets on a first side of the structure;

applying a heat blanket on the first magnetic compaction blanket, wherein the compaction blanket is between the heat blanket and a rework of the structure and heat is conducted from the heat blanket through the first magnetic compaction blanket to heat the rework; and

applying a compression to the heat blanket, wherein the heat blanket is between the compression and the first magnetic compaction blanket, wherein applying the compression to the heat blanket is selected from;

placing a magnetic sheet such that the heat blanket is between the magnetic sheet and the first magnetic compaction blanket and magnetic attraction between the magnetic sheet and the first magnetic compaction blanket pulls the magnetic sheet toward the first magnetic compaction blanket to compress the heat blanket between the magnetic sheet and the first magnetic compaction blanket;

placing compression wrap such that the heat blanket is between the compression wrap and the first magnetic compaction blanket; and

placing a second magnetic compaction blanket comprising a second number of magnets such that the heat blanket is between the second magnetic compaction blanket and the first magnetic compaction blanket and the magnetic attraction between the second magnetic compaction blanket and the first magnetic compaction blanket pulls the second magnetic compaction blanket toward the first magnetic compaction blanket to compress the heat blanket between the second magnetic compaction blanket and the first magnetic compaction blanket.

17. The method of claim 16, wherein the heat is to cure the rework.

18. The method of claim 16, wherein the number of magnets are selected from the group of permanent magnets consisting of rare-earth magnets, iron-boron neodymium magnets, samarium cobalt magnets, and ferrite magnets.

19. The method of claim 16, wherein the first magnetic compaction blanket comprises the number of magnets attached to a magnetic backplane.

20. The method of claim 19, wherein the magnetic backplane comprises a material selected from the group of magnetic materials comprising a metal sheet, a ferromagnetic metal sheet with slits therein, a metal mesh, steel shot, and ferromagnetic powder.

21. The method of claim 16, wherein the first magnetic compaction blanket comprises the number of magnets encapsulated in a non-magnetic material.

22. The method of claim 21, wherein the non-magnetic material is flexible and wherein placing the first magnetic compaction blanket comprises:

placing the first magnetic compaction blanket on a magnetic holder tool;

placing the first magnetic compaction blanket on the structure with the first magnetic compaction blanket on the magnetic holder tool; and

removing the magnetic holder tool from the first magnetic compaction blanket after placing the first magnetic compaction blanket on the structure.

23. The method of claim 16, wherein the magnetic compaction structure is selected from a metal sheet, a metal mesh, and a second magnetic compaction blanket comprising a second number of magnets.

24. The method of claim 16, wherein the structure is a structure on an aircraft.