Additive manufacturing with polyamide consumable materials

1. A method for printing a three-dimensional part with an additive manufacturing system, the method comprising:

providing a consumable material comprising a polyamide blend having at least one semi-crystalline polyamide and at least one amorphous polyamide that is substantially miscible with the at least one semi-crystalline polyamide, wherein the at least one amorphous polyamide constitutes from about 50% by weight to about 85% by weight of the polyamide blend and wherein the consumable material has a solidification temperature and a glass transition temperature, and wherein the consumable material is capable of printing a three-dimensional part having a curl less than about 0.01 inches pursuant to a Curl Bar Test, and has a relative strength in a conditioned state of at least about 1,600 psi;

heating a chamber of the additive manufacturing system or locally heating a deposition region of the additive manufacturing system to a temperature between the solidification temperature and the glass transition temperature of the consumable material;

feeding the consumable material to a liquefier assembly retained by the additive manufacturing system;

melting the consumable material in the liquefier assembly; and

extruding the molten consumable material from the liquefier assembly as a series of roads in the heated chamber or the locally-heated deposition region to print the three-dimensional part in a layer-by-layer manner.

2. The method of claim 1 , wherein the at least one semi-crystalline polyamide comprises a graft semi-crystalline polyamide having impact modifiers grafted to a polyamide backbone.

3. The method of claim 1 , and further comprising printing a support structure in a layer-by-layer manner from a support material comprising acid groups, alcohol groups, or combinations thereof, wherein extruding the molten consumable material from the liquefier assembly as the series of roads in the heated chamber or the locally-heated deposition region comprises depositing the roads on the support structure.

4. The method of claim 3 , and further comprising generating hydrogen bonding between the three-dimensional part and the support structure.

5. The method of claim 3 , and further comprising immersing the three-dimensional part and the support structure in an aqueous solution, which at least partially dissolves the support structure and increases a moisture concentration in the three-dimensional part.

6. The method of claim 1 , and further comprising conditioning the three-dimensional part to increase ductility of the three-dimensional part.

7. A consumable material for use in an additive manufacturing system, the consumable material comprising:

a polyamide blend comprising:

at least one semi-crystalline polyamide; and

at least one amorphous polyamide that is substantially miscible with the at least one semi-crystalline polyamide, wherein the at least one amorphous polyamide constitutes from about 50% by weight to about 85% by weight of the polyamide blend and wherein the consumable material is capable of printing a three-dimensional part having a curl less than about 0.01 inches pursuant to a Curl Bar Test, and a relative strength in a conditioned state of at least about 1,600 psi; and

a physical geometry configured to be received by the additive manufacturing system for printing a three-dimensional part from the consumable material in a layer-by-layer manner using an additive manufacturing technique.

8. The consumable material of claim 7 , wherein the at least one amorphous polyamide constitutes from about 60% by weight to about 80% by weight of the polyamide blend.

9. The consumable material of claim 7 , wherein the at least one semi-crystalline polyamide comprises a graft semi-crystalline polyamide having impact modifiers grafted to a polyamide backbone.

10. The consumable material of claim 7 , wherein the curl of the three-dimensional part is less than 0.008 inches.

11. The consumable material of claim 7 , wherein the at least one semi-crystalline polyamide comprises an aliphatic polyamide having a formula selected from the group consisting of

graft copolymers thereof, and combinations thereof, wherein R 1 , R 2 , and R 3 are each a hydrocarbon chain having 3-12 carbon atoms, and wherein n is a whole number.

12. The consumable material of claim 7 , wherein the at least one semi-crystalline polyamide comprises a PA12 semi-crystalline polyamide having a backbone grafted with an impact modifier pendant chain, wherein the at least one amorphous polyamide comprises a PA12 amorphous polyamide having an amorphous backbone, and wherein the PA12 amorphous polyamide constitutes from about 65% by weight to about 75% by weight of the polyamide blend.

13. A consumable assembly for use in an extrusion-based additive manufacturing system, the consumable assembly comprising:

a container portion;

a consumable filament at least partially retained by the container portion, the consumable filament comprising:

a polyamide blend comprising:

at least one semi-crystalline polyamide; and

at least one amorphous polyamide that is substantially miscible with the at least one semi-crystalline polyamide, wherein the at least one amorphous polyamide constitutes from about 50% by weight to about 85% by weight of the polyamide blend and wherein the consumable material is capable of printing a three-dimensional part having a curl less than about 0.01 inches pursuant to a Curl Bar Test, and a relative strength in a conditioned state of at least about 1,600 psi; and

a filament geometry configured to be received by the extrusion-based additive manufacturing system for printing a three-dimensional part from the consumable filament in a layer-by-layer manner using an additive manufacturing technique.

14. The consumable assembly of claim 13 , wherein the at least one amorphous polyamide constitutes from about 60% by weight to about 80% by weight of the polyamide blend.

15. The consumable assembly of claim 14 , wherein the at least one amorphous polyamide constitutes from about 65% by weight to about 75% by weight of the polyamide blend.

16. The consumable assembly of claim 13 , wherein the at least one semi-crystalline polyamide comprises a graft semi-crystalline polyamide having impact modifiers grafted to a polyamide backbone.

17. The consumable assembly of claim 13 , wherein the at least one amorphous polyamide comprises an aromatic polyamide, a cycloaliphatic polyamide, or combinations thereof.

18. The consumable assembly of claim 13 , wherein the relative strength of the three-dimensional part in the conditioned state is at least about 2,000 psi.