Three dimensional printing
Various embodiments related to three dimensional printers, and reinforced filaments, and their methods of use are described. In one embodiment, a void free reinforced filament is fed into an extrusion nozzle. The reinforced filament includes a core, which may be continuous or semi-continuous, and a matrix material surrounding the core. The reinforced filament is heated to a temperature greater than a melting temperature of the matrix material and less than a melting temperature of the core prior to extruding the filament from the extrusion nozzle.
1. A method for manufacturing a part, the method comprising:
supplying a reinforced filament comprising a matrix material impregnating fiber strands of a multistranded fiber core;
feeding the reinforced filament through an interior channel in a nozzle to exit a distal end of the nozzle to an exterior rounded lip;
guiding the reinforced filament to drag along the exterior rounded lip to transition a direction of the reinforced filament to parallel a deposition surface;
applying heat with the exterior rounded lip to the reinforced filament to soften the matrix material below a melting temperature of the fiber strands; and
applying a downward force toward the deposition surface with the exterior rounded lip to spread the fiber strands within the reinforced filament between the exterior rounded lip and the deposition surface to form the part.
2. The method of claim 1 wherein the matrix material comprises a thermoplastic resin.
3. The method of claim 1 , further comprising forming a shell of the part with the reinforced filament at least partially surrounding a radially inward portion of the part formed from a fill material.
4. The method of claim 1 , further comprising cutting the reinforced filament at or upstream from the exterior rounded lip of the nozzle.
5. The method of claim 4 , further comprising cutting the reinforced filament between the exterior rounded lip of the nozzle and a feeding mechanism.
6. The method of claim 1 , wherein the multistranded fiber core includes continuous fiber strands.
7. The method of claim 1 , wherein the multistranded fiber core includes semi-continuous fiber strands.
8. The method of claim 1 , further comprising pulling the reinforced filament out of the nozzle when a dragging force applied to the reinforced filament is greater than a force threshold of an associated feeding mechanism.
9. A method for manufacturing a part, the method comprising:
feeding a fiber reinforced filament through an interior channel within a heated nozzle to a heated exterior lip;
guiding the fiber reinforced filament to bend from the interior channel and pass between the heated exterior lip and a deposition surface; and
applying a spreading force to the fiber reinforced filament between the heated exterior lip of the heated nozzle and the deposition surface to iron the fiber reinforced filament down into the deposition surface.
10. The method of claim 9 , wherein the spreading force is a compressive force applied downward toward a plane of the deposition surface that is horizontal relative to a direction of the interior channel.
11. The method of claim 9 , wherein a matrix material of the fiber reinforced filament is substantially solid when fed into the interior channel of the nozzle.
12. The method of claim 11 , wherein the matrix material comprises a thermoplastic resin.
13. The method of claim 11 , further comprising applying the heated exterior lip to soften the matrix material below a melting temperature of fiber strands of a multistranded fiber core in the fiber reinforced filament.
14. The method of claim 13 , wherein the multistranded fiber core includes continuous fiber strands.
15. The method of claim 13 , wherein the multistranded fiber core includes semi-continuous fiber strands.
16. The method according to claim 1 , wherein the reinforced filament is supplied as a preimpregnated filament to the interior channel of the nozzle.
17. The method according to claim 1 , wherein the reinforced filament is guided along a smooth transition from the interior channel, along the exterior rounded lip, to a plane of the deposition surface that is horizontal relative to a direction of the interior channel.
18. The method according to claim 1 , wherein the downward force creates a compaction pressure that compresses a first cross-sectional shape of the reinforced filament into a second, flattened cross-sectional shape of the reinforced filament.
19. The method according to claim 1 , wherein the downward force is provided by positioning the exterior rounded lip at a distance less than a cross-sectional diameter of the reinforced filament sufficient to spread the fiber strands within the reinforced filament.
20. The method according to claim 1 , wherein the interior channel of the nozzle is non-divergent, and a diameter of an outlet of the nozzle is equal to or larger than a diameter of an inlet of the nozzle.
21. The method according to claim 9 , wherein the fiber reinforced filament is fed as a preimpregnated filament to the interior channel of the heated nozzle.
22. The method according to claim 9 , wherein the fiber reinforced filament is guided along a smooth transition from the interior channel, along the heated exterior lip, to a plane of the deposition surface that is horizontal relative to a direction of the interior channel.
23. The method according to claim 9 , wherein the spreading force creates a compaction pressure that compresses a first cross-sectional shape of the fiber reinforced filament into a second, flattened cross-sectional shape of the fiber reinforced filament.
24. The method according to claim 9 , wherein the spreading force is provided by positioning the heated exterior lip at a distance less than a cross-sectional diameter of the fiber reinforced filament sufficient to spread the fiber strands within the fiber reinforced filament.
25. The method according to claim 9 , wherein the interior channel of the heated nozzle is non-divergent, and a diameter of an outlet of the heated nozzle is equal to or larger than a diameter of an inlet of the heated nozzle.
26. The method according to claim 9 , wherein the heated exterior lip is an exterior rounded lip.
27. The method according to claim 26 , wherein guiding the fiber reinforced filament includes guiding the fiber reinforced filament to drag along the exterior rounded lip to transition a direction of the fiber reinforced filament to parallel the deposition surface.
28. The method of claim 9 , further comprising forming a shell of the part with the fiber reinforced filament at least partially surrounding a radially inward portion of the part formed from a fill material.
29. The method of claim 9 , further comprising cutting the fiber reinforced filament at or upstream from the heated exterior lip of the heated nozzle.
30. The method of claim 29 , further comprising cutting the fiber reinforced filament between the heated exterior lip of the heated nozzle and a feeding mechanism.
31. The method of claim 9 , further comprising pulling the fiber reinforced filament out of the heated nozzle when a dragging force applied to the fiber reinforced filament is greater than a force threshold of an associated feeding mechanism.