Polymer compositions for extrusion and additive manufacturing processes
A polymer composition capable of being additively manufactured includes a polymer matrix and a magnetically receptive additive. The polymer composition may be additively manufactured or extruded to form a tool which may be used to form a composite part.
1. A method of making a composite part, the method comprising:
additively manufacturing or extruding a polymer composition to form a tool, the polymer composition being capable of induction heating and comprising a polymer matrix and a magnetically receptive additive;
applying a composite part composition or composite part laminate on or to the tool; and
exposing the tool to a magnetic field to thereby induce eddy currents in the magnetically receptive additive, the eddy currents generating sufficient heat in the magnetically receptive additive in the tool to cure the composite part composition or composite part laminate.
2. The method of claim 1 , wherein the magnetically receptive additive comprises a powder or particulate having an average particle size of about 50 μm or smaller.
3. The method of claim 1 , wherein the magnetically receptive additive comprises a plurality of fibers having an average fiber length of about 10 mm or smaller.
4. The method of claim 1 , wherein the magnetically receptive additive comprises a material selected from the group consisting of: iron; cobalt; nickel; naturally occurring minerals; rare earth metals; ferromagnetic materials; alloys thereof; oxides thereof; combinations thereof; hybrids thereof; and mixtures thereof.
5. The method of claim 1 , wherein the magnetically receptive additive comprises a substrate coated with a magnetically receptive coating material.
6. The method of claim 5 , wherein the substrate comprises a non-magnetically receptive substrate material.
7. The method of claim 6 , wherein the non-magnetically receptive substrate material comprises graphite, fiberglass, aramids, combinations thereof, or mixtures thereof.
8. The method of claim 5 , wherein the magnetically receptive coating material comprises a material selected from the group consisting of: iron; cobalt; nickel; naturally occurring minerals; rare earth metals; ferromagnetic materials; alloys thereof; oxides thereof; combinations thereof; hybrids thereof; and mixtures thereof.
9. The method of claim 1 , wherein the polymer composition further comprises one or more auxiliary additives.
10. The method of claim 9 , wherein the one or more auxiliary additives comprises one or more strengtheners, one or more thermal expansion modifiers, or one or more colorants.
11. The method of claim 10 , wherein the one or more strengtheners comprises a material selected from the group consisting of carbon fibers, glass fibers, aramid fibers, metal fibers, metal coated fibers, and combinations thereof.
12. The method of claim 1 , wherein the magnetically receptive additive is present in the polymer composition in an amount of about 1 to about 60 vol % based on 100 vol % of the polymer composition.
13. The method of claim 1 , wherein the additively manufacturing or extruding the polymer composition comprises extruding the polymer composition to form the tool, and the tool has a constant cross-section.
14. The method of claim 1 , wherein the additively manufacturing or extruding the polymer composition comprises additively manufacturing the polymer composition to form the tool, and the tool comprises a net shape.
15. The method of claim 1 , further comprising monitoring a temperature of the tool with one or more thermocouples in contact with or embedded in the tool.
16. The method of claim 15 , further comprising adjusting the temperature of the tool using a controller configured to turn the magnetic field on or off in response to temperature data from the one or more thermocouples.
17. The method of claim 16 , wherein the one or more thermocouples and the controller define a continuous feedback loop in which the controller receives temperature data regarding the temperature of the tool at regular intervals from the one or more thermocouples, and the controller automatically cycles the magnetic field on and off in response to the temperature data when the temperature of the tool reaches or exceeds a predetermined threshold temperature.