Pre-consolidated charges of chopped fiber for composite part fabrication

Patent metadata

Field	Value
Publication number	US-11628632-B2
Application number	US-201916363943-A
Country	US
Kind code	B2
Filing date	Mar 25, 2019
Priority date	Mar 25, 2019
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

Systems and methods are provided for fabricating composite parts. One embodiment is a method for fabricating a composite part, the method comprising: reducing a bulk factor of chips of chopped fiber while forming the chips into a pre-consolidated charge; shaping portions of the pre-consolidated charge into shaped volumetric charges that fit within a die; and compression molding the shaped volumetric charges within the die.

First claim

What is claimed is:

1. A method for fabricating a composite part, the method comprising:
reducing a bulk factor of chips comprising chopped fiber while heating, to a temperature between six hundred and eight hundred degrees Fahrenheit, and forming the chips into a pre-consolidated charge;
separating portions from the pre-consolidated charge;
placing a portion of the portions into a receptacle within a die, wherein the portion has a mass equal to the composite part;
melting the portion within the receptacle and flowing the chopped fiber within the receptacle within the die; and
compression molding the portion into the composite part.

2. The method of claim 1 wherein:
the pre-consolidated charge has a bulk factor between one and two.

3. The method of claim 1 wherein:
reducing the bulk factor comprises placing the chips comprising chopped fiber into a mold.

4. The method of claim 3 wherein:
reducing the bulk factor further comprises applying heat and pressure that plastically deforms the chips into the pre-consolidated charge that conforms with the mold.

5. The method of claim 4 wherein:
reducing the bulk factor further comprises removing the pre-consolidated charge from the mold.

6. The method of claim 1 wherein:
compression molding comprises disposing each of the portions at a corresponding receptacle of the die.

7. The method of claim 6 wherein:
disposing the each of the portions at a corresponding receptacle comprises placing the each of the portions flush against walls of a corresponding receptacle.

8. The method of claim 6 wherein:
compression molding further comprises melting the portions into molten chopped fiber comprising discontinuous fibers and thermoplastic.

9. The method of claim 8 wherein:
The portions each comprise a volume equal to a volume of a composite part that they will be compression molded to form.

10. The method of claim 8 further comprising:
compression molding the molten chopped fiber into shapes defined by corresponding receptacles; and
cooling the molten chopped fiber into composite parts.

11. The method of claim 1 further comprising:
placing a shaped volumetric charge flush against at least one wall of the die.

12. The method of claim 1 wherein:
the reducing the bulk factor is performed at a pressure between twenty and five hundred pounds per square inch.

13. The method of claim 1 wherein:
the chips comprise a thermoplastic; and
the reducing the bulk factor is performed at a temperature above a melting point of the thermoplastic and below a degradation temperature of the thermoplastic.

14. The method of claim 1 wherein:
the separating comprises stamping.

15. The method of claim 1 wherein:
the separating comprises trimming.

16. The method of claim 1 wherein:
the portion does not protrude from the receptacle within the die.

17. The method of claim 1 wherein:
the chips comprise a thermoplastic; and
the compression molding is performed at a temperature above a melting point of the thermoplastic and below a degradation temperature of the thermoplastic.

18. The method of claim 1 wherein:
the compression molding is performed at a pressure between twenty and five thousand pounds per square inch.

19. A method of fabricating a portion of an aircraft, the method comprising:
reducing a bulk factor of chips comprising chopped fiber while heating, to a temperature between six hundred and eight hundred degrees Fahrenheit, and forming the chips into a pre-consolidated charge;
separating shaped volumetric charges from the pre-consolidated charge;
placing a shaped volumetric charge of the shaped volumetric charges into a receptacle within a die, wherein the shaped volumetric charge has a mass equal to the portion of the aircraft;
melting the shaped volumetric charge within the receptacle and flowing the chopped fiber within the receptacle within the die; and
compression molding the shaped volumetric charge into the portion of the aircraft.

20. A non-transitory computer readable medium embodying programmed instructions controlling, when executed by a processor, a method for fabricating a composite part, the method comprising:
reducing a bulk factor of chips comprising chopped fiber while heating, to a temperature between six hundred and eight hundred degrees Fahrenheit, and forming the chips into a pre-consolidated charge;
separating portions from the pre-consolidated charge;
placing a portion of the portions into a receptacle within a die, wherein the portion has a mass equal to the composite part;
melting the portion within the receptacle and flowing the chopped fiber within the receptacle within the die; and
compression molding the portion into the composite part.

Assignees

• Boeing Co

Inventors

• Blom-Schieber Adriana Willempje

Classifications

• B29C70/465 Primary

  and impregnating by melting a solid material, e.g. sheets, powders of fibres · CPC title

• B29C70/545

  Perforating, cutting or machining during or after moulding · CPC title

• B29C2793/0081

  before shaping · CPC title

• B29C70/54

  Component parts, details or accessories; Auxiliary operations {, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing} · CPC title

• B29K2105/12

  of short lengths, e.g. chopped filaments, staple fibres or bristles · CPC title