High rate fabrication of compression molded components

Patent metadata

Field	Value
Publication number	US-9314975-B1
Application number	US-201313870111-A
Country	US
Kind code	B1
Filing date	Apr 25, 2013
Priority date	Apr 25, 2013
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A method for fabricating a thermoplastic composite component comprises inductively heating a thermoplastic pre-form with a first induction coil by inducing current to flow in susceptor wires disposed throughout the pre-form, inductively heating smart susceptors in a molding tool to a leveling temperature with a second induction coil by applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors, shaping the magnetic flux that passes through surfaces of the smart susceptors to flow substantially parallel to a molding surface of the smart susceptors, placing the heated pre-form between the heated smart susceptors; and applying molding pressure to the pre-form to form the composite component.

First claim

We claim:

1. A method for fabricating a thermoplastic composite component, the method comprising:
inductively heating a thermoplastic pre-form with a first induction coil to a processing temperature by inducing current to flow in susceptor wires removably disposed throughout the pre-form;
inductively heating smart susceptors in a molding tool to a leveling temperature with a second induction coil;
placing the heated pre-form between the heated smart susceptors;
removing the susceptor wires by pulling or sliding out of the heated pre-form; and
applying molding pressure to the heated pre-form to form the composite component.

2. The method of claim 1 , wherein the susceptor wires are arranged throughout the pre-form in the shape of a pitchfork.

3. The method of claim 1 , wherein the susceptor wires are inductively heated with the first induction coil to the leveling temperature.

4. The method of claim 3 , wherein the leveling temperature is roughly equal to or up to 20° F. greater than the processing temperature.

5. The method of claim 1 , wherein the pre-form is inductively heated to the processing temperature in less than 20 seconds.

6. The method of claim 1 , wherein the current is induced in the susceptor wires by applying a magnetic field having a strength of about 500 to 10,000 amps per meter.

7. The method of claim 1 , wherein the molding pressure is in a range of 100 to 500 pounds per square inch.

8. The method of claim 1 , wherein inductively heating the smart susceptors in the molding tool comprises applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors and shaping the magnetic flux to flow substantially parallel to a molding surface of the smart susceptors.

9. The method of claim 8 , wherein shaping the magnetic flux comprises placing a flux guidance shell over the smart susceptors while the smart susceptors are inductively heated.

10. The method of claim 9 , wherein the flux guidance shell comprises a material selected from the group consisting of conductive materials, ferromagnetic materials, materials that are conductive and ferromagnetic, and ferrite materials.

11. The method of claim 9 , further comprising removing the flux guidance shell from the smart susceptors prior to placing the heated pre-form between the smart susceptors.

12. The method of claim 8 , wherein the strength of the high-strength magnetic field applied to the smart susceptors is in the range of 5,000 to 50,000 amps per meter.

13. A method for fabricating a thermoplastic composite component, the method comprising:
pre-heating a thermoplastic pre-form to a processing temperature by induction heating of susceptor wires removably disposed throughout the pre-form;
pre-heating smart susceptors in a molding tool to a leveling temperature by applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors and shaping the magnetic flux to flow substantially parallel to a molding surface of the smart susceptors;
placing the pre-heated pre-form between the pre-heated smart susceptors;
removing the susceptor wires by pulling or sliding out of the pre-heated pre-form; and
applying molding pressure to the pre-heated pre-form to form the composite component.

14. The method of claim 13 , wherein shaping the magnetic flux comprises placing a flux guidance shell over the smart susceptors while the smart susceptors are pre-heated.

15. The method of claim 14 , wherein the flux guidance shell comprises a material selected from the group consisting of conductive materials, ferromagnetic materials, materials that are conductive and ferromagnetic, and ferrite materials.

16. The method of claim 14 , further comprising removing the flux guidance shell from the molding tool prior to placing the heated pre-form between the smart susceptors.

17. The method of claim 14 , wherein the smart susceptors are pre-heated to the leveling temperature in about 10-15 seconds.

18. The method of claim 14 , wherein the molding pressure is in a range of 100 to 500 pounds per square inch.

19. The method of claim 13 , wherein the strength of the high-strength magnetic field applied to the smart susceptors is in the range of 5,000 to 50,000 amps per meter.

20. A method for fabricating a thermoplastic composite component, the method comprising:
forming a thermoplastic composite pre-form with susceptor wires removably disposed throughout the pre-form;
positioning the pre-form in a first induction coil to induce current in the susceptor wires and inductively pre-heating the pre-form;
positioning first and second flux guidance shells in an induction molding tool comprising a first tooling die having a first die surface and a second tooling die having a second die surface, a first susceptor positioned on the first die surface, a second susceptor positioned on the second die surface, and an integrated induction coil, the flux guidance shells positioned over the first susceptor and the second susceptor;
inductively pre-heating the first susceptor and the second susceptor to a leveling temperature with the first and second flux guidance shells positioned over the first susceptor and the second susceptor;
removing the first and second flux guidance shells from the induction molding tool;
placing the pre-heated pre-form between the pre-heated first susceptor and second susceptor;
removing the susceptor wires by pulling or sliding out of the pre-heated pre-form; and
applying molding pressure to the pre-heated pre-form to form the composite component.

Assignees

• Boeing Co

Inventors

• Matsen Marc R
• Negley Mark A
• Dykstra William C
• Smith Glen L
• Miller Robert J

Classifications

• B29C43/52

  Heating or cooling · CPC title

• B29C51/421

  of preforms, specially adapted for thermoforming (preheating sheets in general B29B13/023; B29C51/427 takes precedence) · CPC title

• B29C33/06

  using radiation {, e.g. electro-magnetic waves, induction heating} · CPC title

• B29C2035/0811

  using induction · CPC title

• B29C2043/5816

  temperature · CPC title