Methods for forming thermoplastic parts with freeform tooling

• US 10,493,689 B1
• Filed: 09/02/2010
• Issued: 12/03/2019
• Est. Priority Date: 09/02/2010
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Lyons, Brett I., Bartel, Aaron W., Gideon, David Eric
• Primary Examiner(s): Huson, Monica A
• Assistant Examiner(s): Butler, Patrick
• Application Number:
  US12/875,124
• Time in Patent Office: 3,379 Days
• Field of Search: 264308
• CPC Class Codes: B29C 64/10 Processes of additive manufacturing
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

In an embodiment of the disclosure, there is provided a method of prototyping a thermoplastic composite part. The method comprises fabricating one or more discardable freeform tooling elements via a rapid manufacturing process. The method further comprises forming thermoplastic composite materials into a thermoplastic composite prototype part using the one or more discardable freeform tooling elements. The method further comprises separating the thermoplastic composite prototype part from the one or more discardable freeform tooling elements.

Claims

1. A method of prototyping a thermoplastic composite part, the method comprising:

three-dimensional printing (3DP) discardable freeform tooling elements consisting of a soluble mold comprised of a first portion and a second portion, and a soluble core, wherein the soluble mold and the soluble core are solid and consist of a soluble ceramic material, the soluble ceramic material consisting of powdered aluminous silica with silicate and polymer binder;

heating a first prepreg sheet and a second prepreg sheet in a heating element, until the first prepreg sheet and the second prepreg sheet are pliable;

forming a stamp form part assembly comprising, in succession, the first portion of the soluble mold, the first prepreg sheet that is pliable, the soluble core, the second prepreg sheet that is pliable, and the second portion of the soluble mold, wherein the first prepreg sheet forms around contours of a first molded side of the first portion of the soluble mold and around a bottom portion of the soluble core, and further wherein the second prepreg sheet forms around contours of a first molded side of the second portion of the soluble mold and around a top portion of the soluble core;

stamp forming the stamp form part assembly in a stamp forming apparatus using a thermoplastic part forming process comprising a thermoplastic stamp forming process to form thermoplastic composite materials into the thermoplastic composite part, the soluble core being internal to the thermoplastic composite part; and

separating the thermoplastic composite part from the soluble mold, and removing the soluble core from the thermoplastic composite part through dissolution.

2. The method of claim 1, further comprising finishing one or more surfaces of the thermoplastic composite part to obtain desired surface characteristics.

3. The method of claim 1, further comprising after three-dimensional printing (3DP) the discardable freeform tooling elements, finishing one or more surfaces of the discardable freeform tooling elements to obtain desired surface characteristics.

4. The method of claim 1, wherein the three-dimensional printing (3DP) of the discardable freeform tooling elements is based on a digital data file that represents a three-dimensional model of the discardable freeform tooling elements.

6. The method of claim 1, wherein the discardable freeform tooling elements allow for the creation of an interior three-dimensional volume within the thermoplastic composite part.

7. The method of claim 1, wherein the method reduces inventory and inventory storage space for the discardable freeform tooling elements.

8. The method of claim 1, wherein the thermoplastic composite materials and thermoplastic composite part are fiber-reinforced.

9. The method of claim 1, wherein the soluble ceramic material of the soluble mold and the soluble core is soluble in water.

10. The method of claim 1, wherein operating the thermoplastic part forming process further comprises heating the thermoplastic composite materials so that the thermoplastic composite materials are pliable around contours of the mold and the core.

11. The method of claim 10, wherein the thermoplastic composite materials comprise pre-consolidated laminates heated up to about 120°

C. (Celsius) above a glass transition temperature (T_g) of a polymer matrix of the pre-consolidated laminates.

5. A method of prototyping a thermoplastic composite part, the method comprising:

three-dimensional printing (3DP) discardable freeform tooling elements comprising a soluble mold comprised of a first portion and a second portion, and a soluble core, wherein the soluble mold and the soluble core are solid and consist of a soluble ceramic material, the soluble ceramic material consisting of powdered aluminous silica with silicate and polymer binder;

heating a first prepreg sheet and a second prepreg sheet in a heating element, until the first prepreg sheet and the second prepreg sheet are pliable;

forming a stamp form part assembly comprising, in succession, the first portion of the soluble mold, the first prepreg sheet that is pliable, the soluble core, the second prepreg sheet that is pliable, and the second portion of the soluble mold, wherein the first prepreg sheet forms around contours of a first molded side of the first portion of the soluble mold and around a bottom portion of the soluble core, and further wherein the second prepreg sheet forms around contours of a first molded side of the second portion of the soluble mold and around a top portion of the soluble core;

stamp forming the stamp form part assembly in a stamp forming apparatus using a thermoplastic part forming process comprising a thermoplastic stamp forming process to form thermoplastic composite materials into the thermoplastic composite part, the soluble core being internal to the thermoplastic composite part, and the stamp forming apparatus applying a pressure to the stamp form part assembly in a range of from 100 psi (pounds per square inch) to 900 psi; and

separating the thermoplastic composite part from the mold and removing the soluble core from the thermoplastic composite part through dissolution.

12. A method of prototyping a fiber-reinforced thermoplastic composite part, the method comprising:

generating a three-dimensional computer-aided design (3D CAD) model of discardable tooling elements for a prototype part;

three-dimensional printing (3DP) discardable freeform tooling elements based on the 3D CAD model, the discardable freeform tooling elements consisting of a soluble mold comprised of a first portion and a second portion, and a soluble core, wherein the soluble mold and the soluble core are solid and consist of a soluble ceramic material, the soluble ceramic material consisting of powdered aluminous silica with silicate and polymer binder;

heating a first prepreg sheet and a second prepreg sheet in a heating element, until the first prepreg sheet and the second prepreg sheet are pliable;

forming a stamp form part assembly comprising, in succession, the first portion of the soluble mold, the first prepreg sheet that is pliable, the soluble core, the second prepreg sheet that is pliable, and the second portion of the soluble mold, wherein the first prepreg sheet forms around contours of a first molded side of the first portion of the soluble mold and around a bottom portion of the soluble core, and further wherein the second prepreg sheet forms around contours of a first molded side of the second portion of the soluble mold and around a top portion of the soluble core;

stamp forming the stamp form part assembly in a stamp forming apparatus using a thermoplastic part forming process comprising a thermoplastic stamp forming process, to form fiber-reinforced thermoplastic composite materials into the fiber-reinforced thermoplastic composite part;

separating the fiber-reinforced thermoplastic composite part from the soluble mold and removing the soluble core from the fiber-reinforced thermoplastic composite part through dissolution; and

discarding the discardable freeform tooling elements.

13. The method of claim 12, further comprising after separating the fiber-reinforced thermoplastic composite part, finishing one or more surfaces of the fiber-reinforced thermoplastic composite part to obtain desired surface characteristics.

14. The method of claim 12, further comprising after three-dimensional printing (3DP) the discardable freeform tooling elements, finishing one or more surfaces of the discardable freeform tooling elements to obtain desired surface characteristics.

15. The method of claim 12, wherein the soluble core is in a form of a tube.

16. The method of claim 12, wherein the thermoplastic part forming process is the thermoplastic stamp forming process.

17. The method of claim 12, wherein the discardable freeform tooling elements allow for the creation of an interior three-dimensional volume within the fiber-reinforced thermoplastic composite part.

18. The method of claim 12, wherein the soluble ceramic material of the soluble mold and the soluble core is soluble in water.

19. The method of claim 12, wherein operating the thermoplastic part forming process further comprises heating the fiber-reinforced thermoplastic composite materials so that the fiber-reinforced thermoplastic composite materials are pliable around contours of the mold and the core.

20. The method of claim 19, wherein the fiber-reinforced thermoplastic composite materials comprise pre-consolidated laminates heated up to about 120°

C. (Celsius) above a glass transition temperature (T_g) of a polymer matrix of the pre-consolidated laminates.