Systems and methods for controlling permeability in vacuum infusion processes

• US 9,079,367 B2
• Filed: 08/25/2011
• Issued: 07/14/2015
• Est. Priority Date: 08/25/2010
• Status: Expired due to Fees

• Current Assignee: University of Delaware
• Original Assignee: University of Delaware
• Inventors: Alms, Justin B., Advani, Suresh G., Glancey, James L.
• Primary Examiner(s): Johnson, Christina
• Assistant Examiner(s): Schmerfeld, David
• Application Number:
  US13/217,641
• Publication Number:
  US 20120068382A1
• Time in Patent Office: 1,419 Days
• US Class Current: 1/1
• CPC Class Codes: B29C 2791/007 Using fluid under pressure
• CPC Class Codes: B29C 33/32 using magnetic means
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29C 70/443 and impregnating by vacuum or injection
• CPC Class Codes: B29C 70/546 Measures for feeding or distributing the matrix material in the reinforcing structure

Abstract

Systems and methods for controlling permeability in vacuum infusion processes are disclosed. A system includes a tool surface, a flexible film, a preform, a magnetic field source, and a magnetic element. The flexible film has a periphery sealingly coupled to the tool surface to define a volume. The preform is disposed within the volume. The magnetic field source is configured to generate a magnetic field. The magnetic element is positioned to receive the magnetic field generate by the magnetic field source. The magnetic element is configured to move the flexible film away from the upper side of the tool surface under application of the magnetic field. A method includes generating a magnetic field with the magnetic field source and receiving the magnetic field with the magnetic element to move the flexible film away from the upper side of the tool surface, thereby increasing permeability of the preform.

Claims

1. A method for controlling permeability in a vacuum infusion process comprising:

sealing a periphery of a flexible film to a tool surface to define a volume between a lower side of the flexible film and an upper side of the tool surface;

disposing a preform within the volume;

providing a plurality of magnetic elements, each of the plurality of magnetic elements configured to move a portion of the flexible film away from the upper side of the tool surface under the application of a magnetic field, each of the plurality of magnetic elements moveable relative to one another in an attraction or repulsion direction of the magnetic field, and each of the plurality of magnetic elements having a relative size smaller than the flexible film overlying the preform, wherein the plurality of magnetic elements comprise a first subset consisting of one or more but fewer than all of the plurality of magnetic elements and a second subset consisting of one or more but fewer than all of the plurality of magnetic elements, and wherein the first subset is different than the second subset; and

further comprising the sequential steps of;

generating a first magnetic field with one or more magnetic field sources;

receiving the first magnetic field with the first subset, thereby increasing permeability of at least a portion of the preform corresponding to an area of the flexible film moved by the first subset;

moving the one or more magnetic field sources, thereby relocating the one or more magnetic field sources in a direction parallel to the tool surface;

generating a second magnetic field with the one or more magnetic field sources; and

receiving the second magnetic field with the second subset, thereby increasing permeability of at least a portion of the preform corresponding to an area of the flexible film moved by the second subset.

2. The method of claim 1, wherein the receiving the first magnetic field step comprises:

attracting the first subset toward the one or more magnetic field sources under the application of the first magnetic field.

3. The method of claim 2, wherein the receiving the first magnetic field step comprises:

attracting the first subset toward the one or more magnetic field sources to contact the one or more magnetic field sources with the first subset or the flexible film when moving under the application of the first magnetic field.

4. The method of claim 3, further comprising the step of:

moving the one or more magnetic field sources in a direction away from the upper side of the tool surface.

5. The method of claim 1, wherein the receiving the first magnetic field step comprises:

repelling the first subset away from the one or more magnetic field sources under the application of the first magnetic field.

6. The method of claim 1, further comprising the step of:

injecting a polymer resin into the volume when the area of the flexible film is moved away from the upper side of the tool surface by the first subset.

7. The method of claim 1, wherein the receiving the first magnetic field step comprises increasing the permeability of at least a portion of the preform by increasing a space between layers of the preform.

8. The method of claim 1, wherein the portion of the flexible film moved by the first subset is smaller in relative dimension than the flexible film overlying the preform.

9. The method of claim 1, wherein each of the plurality of magnetic elements comprises a metal sheet.

10. The method of claim 1, wherein each of the plurality of magnetic elements comprises a portion of metal wire mesh.

11. The method of claim 10, wherein the portion of metal wire mesh is a connected portion of a larger metal wire mesh overlying the preform.

12. The method of claim 10, wherein the portion of metal wire mesh comprises one or more of a plurality of discrete metal wire mesh elements, wherein each discrete metal wire mesh element has a relative size smaller than the flexible film overlying the preform.

13. The method of claim 10, wherein each of the plurality of magnetic elements comprises a component magnet.

14. The method of claim 1, wherein each of the one or more magnetic field sources is configured to generate a corresponding magnetic field received by fewer than all of the plurality of magnetic elements.

15. The method of claim 14, wherein each of the one or more magnetic field sources comprises an electromagnetic magnetic field source connected to a source of power,

wherein the receiving the first magnetic field step comprises applying the first magnetic field to the first subset by providing power to the one or more magnetic field sources, and

wherein the receiving the second magnetic field step comprises applying the second magnetic field to the second subset by providing power to the one or more magnetic field sources.

16. The method of claim 1, further comprising the step of:

identifying an area of the preform in need of increased permeability,

wherein the receiving the first magnetic field step comprises applying the first magnetic field to the first subset to increase permeability in the identified area.