Continuous Molding of Thermoplastic Laminates

• US 20110206906A1
• Filed: 02/24/2010
• Published: 08/25/2011
• Est. Priority Date: 02/24/2010
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Fox, James R., Wilkerson, Randall D., Rubin, Alexander M.
• Granted Patent: US 10,821,653 B2
• Time in Patent Office: Days
• US Class Current: 428/188
• CPC Class Codes: B29C 53/04 of plates or sheets B29C63/04 takes precedence; bending or folding paper B31F1/0003; folding films B65H45/00
• CPC Class Codes: B29L 2031/003 having a profiled transverse cross-section
• CPC Class Codes: Y10T 156/1007 Running or continuous length work
• CPC Class Codes: Y10T 156/1013 and edge-joining of one piece blank to form tube
• CPC Class Codes: Y10T 428/24 Structurally defined web or sheet [e.g., overall dimension, etc.]
• CPC Class Codes: Y10T 428/24744 Longitudinal or transverse tubular cavity or cell

Abstract

An elongate thermoplastic composite member is fabricated by a continuous molding process. A pre-consolidated thermoplastic laminate is softened by heating it to a temperature below its melting layup, and is fed substantially continuously through multiple sets of tool dies. The tool dies incrementally mold portions of softened laminate over a mandrel to form the laminate into a shape having a closed cross section.

Claims

1. A method of fabricating a composite part, comprising:

producing a pre-consolidated thermoplastic laminate;

feeding the pre-consolidated laminate substantially continuously through a forming zone;

heating the pre-consolidated laminate to a temperature sufficient to allow forming of the laminate but below the melting temperature of the laminate; and

incrementally forming features into sections of the heated laminate as the heated laminate is being fed through the forming zone.

2. The method of claim 1, further comprising:

cooling the laminate after the features have been formed into the laminate.

3. The method of claim 1, wherein producing the pre-consolidated thermoplastic laminate includes:

forming a layup of multiple plies of a reinforced thermoplastic,

molding at least one shape into the layup,

consolidating the shaped layup.

4. The method of claim 2, wherein:

heating the pre-consolidated laminate is performed a section at a time, and

cooling the pre-consolidated laminate is performed a section at a time.

5. The method of claim 1, wherein incrementally forming features into sections of the heated laminate is performed using by a set of individual tool dies to respectively mold portions of the feature into the laminate.

6. The method of claim 1, wherein incrementally forming features into sections of the heated laminate includes forming portions of the heated laminate over a mandrel.

7. The method of claim 1, wherein feeding the pre-consolidated laminate substantially continuously through a forming zone is performed along a curved path;

8. The method of claim 1, wherein incrementally forming features into sections of the heated laminate includes molding a curvature into the laminate along its length.

9. A composite part formed by the method of claim 1.

10. A method of fabricating a composite part, comprising:

laying up a multi-ply thermoplastic laminate;

consolidating the laminate layup;

heating the consolidated laminate to a preselected temperature below its melting point but sufficient to soften the laminate for molding;

feeding the heated laminate substantially continuously through multiple sets of tool dies; and

,

using the tool dies to mold at least one feature into the heated laminate as the laminate is being fed substantially continuously through the tool dies, including using each of the tool dies to partially mold the feature into the heated laminate.

11. The method of claim 10, further comprising:

cooling the laminate after the feature has been molded into the laminate; and

curing the laminate.

12. The method of claim 10, further comprising:

using the tool dies to mold a curvature into the laminate along its length.

13. The method of claim 11, wherein:

heating the laminate is performed a section at a time and includes limiting the time during which each section of the laminate is heated to the preselected temperature for a period that results in maintenance of the structural properties of the consolidated laminate prior to being heated, and

cooling the pre-consolidated laminate is performed a section at a time.

14. The method of claim 10, wherein:

using the tool dies to mold at least one feature into the heated laminate includes forming the heated laminate over a mandrel, and

the laminate is maintained at the preselected temperature during the period that the laminate is being formed over the mandrel.

15. The method of claim 10, further comprising:

forming at least one shape into the consolidated laminate along its length before the feature is molded into the laminate.

16. The method of claim 10, wherein molding the feature includes forming the consolidated laminate into a closed cross sectional shape.

17. A composite part made by the method of claim 10.

18. A method for continuously producing an elongate part having a closed cross section, comprising:

feeding a pre-consolidated thermoplastic laminate substantially continuously through a compression molding machine;

softening the laminate by heating the laminate to a temperature below its melting point; and

molding portions of features into the softened laminate sequentially using differing tool dies in the machine as the laminate is being fed substantially continuously through the machine, including molding portions of the heated laminate around a mandrel to at least partially close the cross section of the molded part.

19. The method of claim 18, further comprising:

cooling the laminate after the features have been molded into the laminate.

20. The method of claim 18, further comprising:

molding at least one shape into the laminate before the laminate is fed into the machine.

21. The method of claim 18, wherein feeding the pre-consolidated laminate substantially continuously through the compression molding machine is performed along a curved path.

22. The method of claim 18, wherein molding portions of features into the softened laminate includes molding a curvature into the laminate along its length.

23. A composite part produced by the method of claim 18.

24. A method of fabricating an elongate composite part having a closed cross sectional shape, comprising:

laying up a length of a multi-ply thermoplastic laminate;

forming a shape into the laid up laminate along its length;

consolidating the shaped laminate, including heating the laminate to at least its melting point and then cooling the laminate;

reheating the consolidated laminate to a temperature below its melting point but sufficient to soften the laminate for molding;

feeding the heated laminate substantially continuously through multiple sets of tool dies; and

,

using the tool dies to mold the softened laminate over a mandrel to form the closed cross section shape as the laminate is being fed substantially continuously through the tool dies, including using each of the tool dies to partially mold the feature into the heated laminate.