Additive manufacturing with polyamide consumable materials

• US 9,592,530 B2
• Filed: 03/15/2013
• Issued: 03/14/2017
• Est. Priority Date: 11/21/2012
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Rodgers, Luke M. B.
• Primary Examiner(s): Woodward, Ana
• Application Number:
  US13/833,526
• Publication Number:
  US 20140141166A1
• Time in Patent Office: 1,460 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B05D 3/0218 Pretreatment, e.g. heating the substrate
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 7/06 Elements
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 77/02 Polyamides derived from omega-amino carboxylic acids or from lactams thereof C08L77/10 takes precedence
• CPC Class Codes: C08L 77/06 Polyamides derived from polyamines and polycarboxylic acids C08L77/10 takes precedence

Abstract

A consumable material for use in an additive manufacturing system, the consumable filament comprising a polyamide blend of at least one semi-crystalline polyamide, and at least one amorphous polyamide that is substantially miscible with the at least one semi-crystalline polyamide, 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. The consumable material is preferably capable of printing three-dimensional parts having good part strengths and ductilities, and low curl.

Claims

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 graft semi-crystalline polyamide having one or more impact modifiers grafted to the polyamide backbone and at least one amorphous polyamide having one or more impact modifiers grafted to the polyamide backbone to form a graft amorphous polyamide that is substantially miscible with the at least one graft semi-crystalline polyamide, wherein the consumable material has a solidification temperature and a glass transition temperature, and wherein the consumable material is suitable for printing a three-dimensional part having a curl less than or equal to 0.01 inches pursuant to a Curl Bar Test, and has a relative strength in a conditioned state of at least 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; and

conditioning the three dimensional part to a moisture content in the range of 0.5 wt. % and 2.0 wt. %.

2. The method of claim 1, wherein the at least one amorphous polyamide constitutes from about 30% by weight to about 70% by weight of the polyamide blend.

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 the moisture concentration in the three-dimensional part.

6. The method of claim 1, wherein conditioning the three-dimensional part increases ductility of the three-dimensional part.

7. A consumable material for use in an additive manufacturing system configured to build a three-dimensional part in a layer by layer manner, the consumable material comprising:

a polyamide blend comprising;

at least one graft semi-crystalline polyamide, wherein the at least one graft semi-crystalline polyamide has one or more impact modifiers grafted to the polyamide backbone; and

at least one amorphous polyamide having one or more impact modifiers grafted to the polyamide backbone to form at least one graft amorphous polyamide that is substantially miscible with the at least one graft semi-crystalline polyamide, wherein the consumable material is suitable for printing a three-dimensional part having a curl less than or equal to 0.01 inches pursuant to a Curl Bar Test, and a relative strength of at least 1,600 psi when the moisture content of the three-dimensional part is between 0.5 wt. % and 2.0 wt. %.

8. The consumable material of claim 7, wherein the at least one graft amorphous polyamide constitutes from about 30% by weight to about 70% by weight of the polyamide blend.

9. The consumable material of claim 8, wherein the at least one graft amorphous polyamide constitutes from about 45% by weight to about 55% by weight of the polyamide blend.

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 graft semi-crystalline polyamide comprises an aliphatic polyamide having a formula selected from the group consisting of

12. The consumable material of claim 11, wherein the at least one semi-crystalline polyamide comprises a copolymer of the formulas.

13. The consumable material of claim 7, wherein the at least one graft semi-crystalline polyamide comprises a polycaprolactam (PA6) semi-crystalline polyamide grafted with an impact modifier pendant chain, wherein the at least one amorphous polyamide comprises an amorphous backbone derived from trimethylhexamethylenediamine and terephthalic acid (PA6/3T), and wherein the trimethylhexamethylenediamine and terephthalic acid (PA6/3T) amorphous polyamide constitutes from about 30% by weight to about 70% by weight of the polyamide blend.

14. The consumable material of claim 7, wherein the impact modifier grafted to both the amorphous polyamide and the semi-crystalline polyamide comprises between 5% and 15% by weight of the amorphous polyamide and the semi-crystalline polyamide.

15. A filament for use in an additive manufacturing system configured to build a three-dimensional part in a layer by layer manner, the filament comprising:

a polyamide blend comprising;

a semi-crystalline polyamide component comprising a polycaprolactam (PA6) semi-crystalline polyamide, wherein at least a portion of the polycaprolactam (PA6) semi-crystalline polyamide is grafted with an impact modifier pendant chain wherein the impact modifier comprises from about 1% to about 20% by weight of the grafted 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 polyamide comprises an amorphous backbone derived from trimethylhexamethylenediamine and terephthalic acid (PA6/3T) wherein at least a portion of the trimethylhexamethylenediamine and terephthalic acid (PA6/3T) amorphous polyamide is grafted with an impact modifier pendant chain wherein the impact modifier comprises from about 1% to about 20% by weight of the grafted amorphous polyamide, and wherein the trimethylhexamethylenediamine and terephthalic acid (PA6/3T) amorphous polyamide constitutes from about 40% by weight to about 60% by weight of the polyamide blend, wherein the filament is suitable for printing a three-dimensional part having a curl less than or equal to 0.01 inches pursuant to a Curl Bar Test, and a relative strength of at least 1,600 psi when the moisture content of the three-dimensional part is between 0.5 wt. % and 2.0 wt. %.

16. The filament of claim 15, wherein the polycaprolactam (PA6) semi-crystalline polyamide is grafted with an impact modifier pendant chain wherein the impact modifier comprises from about 5% to about 15% by weight of the grafted semi-crystalline polyamide and wherein the grafted semi-crystalline polyamide comprises from about 80% to about 100% by weight of the semi-crystalline polyamide.

17. The filament of claim 16, wherein the amorphous backbone is derived from trimethylhexamethylenediamine and terephthalic acid (PA6/3T), wherein the trimethylhexamethylenediamine and terephthalic acid (PA6/3T) amorphous polyamide is grafted with an impact modifier pendant chain wherein the impact modifier comprises from about 5% to about 15% by weight of the grafted amorphous polyamide, and wherein the grafted amorphous polyamide comprises from about 80% to about 100% by weight of the amorphous polyamide.

18. The filament of claim 17, wherein the trimethylhexamethylenediamine and terephthalic acid (PA6/3T) amorphous polyamide constitutes from about 45% by weight to about 55% by weight of the polyamide blend.

19. The filament of claim 15 and wherein the polyamide blend has a melt flow index ranging from about 1 gram/10 minutes to about 4 grams/10 minutes pursuant to ASTM D1238-10 with a 2.16 kilogram weight at a temperature of 260°

C.