Computer Controlled Flow Manipulation For Vacuum Infusion Processes

• US 20110046771A1
• Filed: 08/18/2010
• Published: 02/24/2011
• Est. Priority Date: 08/18/2009
• Status: Active Grant

• Current Assignee: University of Delaware
• Original Assignee: University of Delaware
• Inventors: Glancey, James L., Advani, Suresh G., Alms, Justin B.
• Granted Patent: US 8,808,612 B2
• Time in Patent Office: Days
• US Class Current: 700/114
• 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

Methods and apparatus for vacuum infusing resin into a fabric preform within a mold. The methods comprise increasing permeability in a selected region, such as by deploying a VIPR chamber in a location corresponding to the resin injection port corresponding to the resin flow front furthest from the mold vent or a location identified by predictive modeling as best to achieve a desired flow front geometry. Suitable apparatus comprise a VIPR chamber, an image detector for detecting resin flow fronts, a processor programmed to identify a desired location to deploy the VIPR chamber, and an automatic positioner for moving the VIPR chamber to the identified location.

Claims

1. A method for vacuum infusing resin into a fabric preform within a mold, the mold comprising a tool surface, a plurality of resin injection ports, at least one vent, and a flexible film covering the preform and sealed to the tool surface, the method comprising the steps of:

(a) injecting resin through the plurality of resin injection ports;

(b) detecting a plurality of resin flow fronts emanating from the resin injection ports;

(c) determining a distance between each resin flow front and the at least one vent;

(d) identifying the resin flow front that is furthest from the vent; and

(e) deploying a VIPR chamber in a sealed relationship with the flexible film in a location corresponding to the flow front furthest from the vent and introducing vacuum into the VIPR chamber.

2. The method of claim 1, comprising periodically repeating steps (b)-(e).

3. The method of claim 2, comprising moving the VIPR chamber from a first location corresponding to a first flow front dictated by one performance of step (d) to a second location corresponding to a second flow front dictated by a later performance of step (d).

4. The method of claim 3, wherein each of the first location and the second location comprises a location in which the VIPR chamber is juxtaposed over one of the injection ports.

5. The method of claim 1, wherein the step of detecting the plurality of resin flow fronts comprises creating an image of the plurality of flow fronts relative to the injection ports and the at least one vent using an image detector connected to a computer processor.

10. The method of claim 1, wherein the step of detecting the plurality of resin flow fronts comprises creating an image of the plurality of flow fronts relative to the injection ports and the at least one vent using an image detector connected to a computer processor.

6. A method of vacuum infusing resin into a fabric preform within a mold, the mold comprising a tool surface, a plurality of resin injection ports, at least one vent, and a flexible film covering the preform and sealed to the tool surface, the method comprising the steps of:

(a) injecting resin through the plurality of resin injection ports;

(b) detecting a plurality of resin flow fronts emanating from the resin injection ports;

(c) determining a distance between each resin flow front and the at least one vent;

(d) using a processor programmed with a predictive model to evaluate the impact of sealing a VIPR chamber over the flexible film in each of a plurality of locations, and selecting a best location based on results of the evaluation; and

(e) deploying the VIPR chamber in the identified best location and introducing a vacuum into the VIPR chamber.

7. The method of claim 6, comprising periodically repeating steps (b)-(e).

8. The method of claim 7, comprising moving the VIPR chamber from a first best location dictated by one performance of step (d) to a second location dictated by a later performance of step (d).

9. The method of claim 8, wherein each of the first location and the second location comprises a location in which the VIPR chamber is juxtaposed over one of the injection ports.

11. Apparatus for infusing resin into a fabric preform within a mold, the mold comprising a tool surface, a plurality of resin injection ports, at least one vent, and a flexible film covering the preform and sealed to the tool surface, the apparatus comprising:

a VIPR chamber adapted to be sealingly coupled to the flexible film;

an image detector mounted above the mold for identifying a plurality of resin flow fronts emanating from the resin injection ports relative to the at least one vent;

a processor connected to the image detector and programmed to determine a distance between each resin flow front and the at least one vent, identify the resin flow front furthest from the vent, and instruct placement of the VIPR chamber in an identified location where increased permeability is desired; and

an automatic positioner attached to the VIPR chamber for receiving instructions from the processor and moving the VIPR chamber to the location identified by the processor.

12. The apparatus of claim 11, wherein the processor comprises instructions for identifying the location for placement of the VIPR chamber based upon which resin flow front is furthest from the vent.

13. The apparatus of claim 11, wherein the processor is programmed with a predictive model and instructions to run the predictive model to evaluate the impact of placing the VIPR chamber in each of a plurality of locations and to identify the location for placement of the VIPR chamber based upon results of the predictive model evaluation.

14. The apparatus of claim 11, wherein the image detector comprises a digital camera for visibly detecting the plurality of resin flow fronts.

15. The apparatus of claim 11, wherein the positioner comprises a gantry system comprising:

one or more actuators for moving the VIPR chamber along a set of linear or planar coordinates corresponding to planar coordinates of the tool surface; and

a piston operable in a direction perpendicular to the tool surface for moving the VIPR chamber in and out of a sealingly coupled relationship with the flexible film.

16. The apparatus of claim 11, wherein:

the mold further comprises;

a top plate comprising the plurality of injection ports and the at least one vent;

a bottom plate spaced from the top plate and having a plurality of piston apertures aligned with the injection ports in the top plate;

a membrane disposed over the bottom plate;

at least one resin channel defined between the top plate and the membrane in fluid communication with one or more of the plurality of resin inlets;

at least one vacuum channel defined between the top plate and the membrane in fluid communication with the at least one vent outlet; and

the apparatus further comprises;

a piston vacuum chamber sealed to the bottom plate of the mold;

a plurality of pistons mounted below the bottom plate within the piston vacuum chamber, each piston aligned with one of the piston apertures in the bottom plate, each piston extendable between a closed port position in which the piston urges the membrane into a position blocking the corresponding injection port or vent and an open port position that permits resin flow from the resin channel into the injection port or communication of vacuum between the vent and the vacuum channel; and

a vacuum regulator attached to the piston vacuum chamber for equalizing pressure on opposite sides of the membrane when the mold is under vacuum.

17. A method for vacuum infusing resin into a preform within a mold, the mold comprising a tool surface, a plurality of resin injection ports, at least one vent, and a flexible film covering the preform and sealed to the tool surface, the method comprising the steps of:

(a) injecting resin through the plurality of resin injection ports;

(b) detecting a plurality of resin flow fronts emanating from the resin injection ports;

(c) identifying a region of the mold in need of increased resin permeability;

(e) locally increasing resin permeability in the identified region.

18. The method of claim 17, wherein the detecting step comprises using an image capture device and the step of locally increasing resin permeability comprises moving a VIPR chamber to the identified region, sealing the VIPR chamber to the flexible film in the identified region, and introducing vacuum into the VIPR chamber.

19. The method of claim 17, wherein the identifying step comprises determining a distance between each resin flow front and the at least one vent;

identifying the resin flow front that is furthest from the vent, and selecting the identified region to include a region overlying the resin injection port corresponding to the resin flow front furthest from the vent.

20. The method of claim 17, wherein the identifying step comprises using a processor programmed with a predictive model to evaluate the impact of increasing permeability in each of a plurality of locations, and selecting the identified region based on results of the evaluation.