IN-SITU POLYMERIZATION OF POLYAMIDES FOR COMPOSITE PART REPAIR

• US 20170203524A1
• Filed: 01/03/2017
• Published: 07/20/2017
• Est. Priority Date: 01/15/2016
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company), Teijin Limited
• Original Assignee: GM Global Technology Operations LLC (General Motors Company), Teijin Limited
• Inventors: Ryutani, Tomohiro, Goto, Takashi, Huang, Xiaosong
• Granted Patent: US 10,695,993 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 73/02 using liquid or paste-like material B29C73/16 takes precedence
• CPC Class Codes: B29C 73/06 using plugs sealing in the hole
• CPC Class Codes: B29C 73/10 using patches sealing on the surface of the article B29C73/14 takes precedence
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0002 monomers or prepolymers
• CPC Class Codes: B29K 2105/0005 containing compounding ingredients releasing, lubricating or separating agents B29C33/56, fibers B29K2105/08, B29K2105/12; fillers B29K2105/16, recycled material B29K2105/26
• CPC Class Codes: C08J 2377/02 Polyamides derived from omega-amino carboxylic acids or from lactams thereof C08J2377/10 takes precedence
• CPC Class Codes: C08J 5/04 Reinforcing macromolecular compounds with loose or coherent fibrous material

Abstract

Methods of repairing defects in polymeric composite structures are provided. The methods include filling or bonding defects with a pre-polymerization solution and polymerizing the pre-polymerization solution in situ. Patches or support structures can be disposed at the site of the defect to increase the strength of the repair or to make the repair cosmetically pleasing, respectively. Such a method of repairing a defect may include applying a pre-polymer solution having a reinforcing material and a monomer to the defect in a polymeric composite structure; disposing a support structure on a surface of the polymeric composite structure over at least a portion of the defect having the applied pre-polymer solution; and polymerizing the monomer in the pre-polymer solution to form a repaired region in the polymeric composite structure including a polymer having the reinforcing material distributed therein.

Claims

1. A method of repairing a defect in a polymeric composite structure, the method comprising:

applying a pre-polymer solution comprising a reinforcing material and a monomer to the defect in the polymeric composite structure;

disposing a support structure on a first surface of the polymeric composite structure over at least a portion of the defect having the applied pre-polymer solution; and

polymerizing the monomer in the pre-polymer solution to form a repaired region in the polymeric composite structure comprising a polymer having the reinforcing material distributed therein.

2. The method according to claim 1, wherein the pre-polymer solution further comprises at least one of an initiator or an activator.

3. The method according to claim 2, wherein the pre-polymer solution comprises an initiator and an activator, and wherein the monomer is caprolactam, the activator is hexamethylene diisocyanate, and the initiator is caprolactam magnesium bromide.

4. The method according to claim 1, wherein the polymeric composite structure has a corrugated surface, and disposing a support structure on the first surface of the polymeric composite structure comprises disposing a rigid support structure having a corrugated surface that matches the corrugated surface of the polymeric composite structure.

5. The method according to claim 1, further comprising:

applying pressure to the support structure prior to and during the polymerizing of the monomer in the pre-polymer solution.

6. The method according to claim 1, wherein the polymerizing of the monomer in the pre-polymer solution comprises applying heat or light to the pre-polymer solution.

7. The method according to claim 1, wherein the polymerizing of the monomer in the pre-polymer solution comprises disposing a heat blanket on an exposed surface of the support structure and applying heat generated from the heat blanket to the pre-polymer solution through the support structure.

8. The method according to claim 1, wherein the polymeric composite structure comprises a polyamide-based polymer composite and the polymerizing of the monomer in the pre-polymer solution generates a polymer comprising polyamide 6 in situ.

9. The method according to claim 1, further comprising:

disposing at least one polymeric composite sheet on a surface of the polymeric composite structure opposite the surface on which the support structure is disposed.

10. The method according to claim 1, wherein the reinforcing material is selected from the group consisting of carbon fibers, glass fibers, chopped fibers, continuous fibers, fabrics, mesh, powder, and combinations thereof.

11. The method according to claim 1, further comprising:

removing the support structure from the first surface of the polymeric composite structure after the repair region is formed.

12. The method according to claim 1, further comprising, prior to the polymerizing, disposing a first patch onto a second surface of the polymeric composite structure that spans the defect, the second surface being opposite the first surface.

13. The method according to claim 12, further comprising, prior to the disposing a support structure on the first surface, disposing a second patch to the first surface of the polymeric composite structure that spans the defect.

14. The method according to claim 12, wherein the defect is a hole and the method further comprises:

disposing a piece of a polymeric composite material within the hole such that a channel is defined between a first edge of the piece of a polymeric composite material and a second edge of the polymeric composite structure that defines the hole,

wherein the channel is filled with the pre-polymer solution after the applying.

15. The method according to claim 12, wherein polymeric composite structure is corrugated, and the disposing a support structure on the first surface of the polymeric composite structure comprises disposing a support structure having a corrugated surface that matches the corrugated polymeric composite structure.

16. A method of repairing a defect in a polymeric composite structure, the method comprising:

exposing a portion of a first polymeric composite panel located immediately adjacent to a section of the polymeric composite structure having the defect;

removing the section of the polymeric composite structure having the defect;

applying a pre-polymer solution comprising a reinforcing material and a monomer to the portion of the first polymeric composite panel;

disposing a surface of a second polymeric composite panel on the portion of the first polymeric composite, wherein the second polymeric composite panel replaces the section of the polymeric composite structure having the defect; and

polymerizing the monomer in the pre-polymer solution to generate a third polymeric composite in situ that bonds the second polymeric composite panel to the first polymeric composite panel.

17. The method according to claim 16, further comprising:

applying pressure to the second polymeric composite panel and the first polymeric composite panel prior to and during the polymerizing.

18. The method according to claim 17, wherein the applying pressure comprises sealing the second polymeric composite panel and the first polymeric composite panel in vacuum bagging and applying a negative pressure until polymerizing is completed.

19. The method according to claim 16, wherein the pre-polymer solution further comprises an activator and an initiator and the reinforcing material is selected from the group consisting of carbon fibers, glass fibers, chopped fibers, continuous fibers, fabrics, mesh, powder, and combinations thereof, such that the polymerizing of the monomer in the pre-polymer solution occurs in situ.

20. A polymer composite structure, comprising:

a polymeric composite panel having a repaired region, the repaired region comprising a defect filled with a polymer comprising a reinforcing material selected from the group consisting of carbon fibers, glass fibers, chopped fibers, continuous fibers, fabrics, mesh, powder, and combinations thereof,

wherein the repaired region has an exposed surface having a grain or pattern that matches a grain or pattern in an exposed surface of the polymeric composite structure.