Extrusion-based additive manufacturing process with part annealing

• US 8,460,755 B2
• Filed: 04/07/2011
• Issued: 06/11/2013
• Est. Priority Date: 04/07/2011
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Rodgers, Luke M. B.
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US13/081,956
• Publication Number:
  US 20120258250A1
• Time in Patent Office: 796 Days
• Field of Search: None
• US Class Current: 427/256
• 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 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 40/20 Post-treatment, e.g. curing, coating or polishing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing

Abstract

A method for building a three-dimensional part, the method comprising providing a printed three-dimensional part and support structure, where the support structure comprises at least two polymers having different glass transition temperatures. The method also comprises annealing the three-dimensional part.

Claims

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

printing a support structure from a support material with the extrusion-based additive manufacturing system using a layer-based additive manufacturing technique, wherein the support material comprises at least two polymers comprising a first polymer having a first glass transition temperature, and a second polymer that is substantially immiscible with the first polymer, the second polymer having a second glass transition temperature that is greater than the first glass transition temperature of the first polymer by at least about 10°

C.;

in coordination with the printing of the support structure, printing the three-dimensional part from a part material with the extrusion-based additive manufacturing system using the layer-based additive manufacturing technique;

heating the printed support structure and the printed three-dimensional part to at least one temperature that is above a glass transition temperature of the part material, and that is below a glass transition temperature of at least one of the polymers of the support material; and

cooling the heated support structure and the heated three-dimensional part.

2. The method of claim 1, wherein the second glass transition temperature of the second polymer is at least about 20°

C. greater than the first glass transition temperature of the first polymer.

3. The method of claim 2, wherein the second glass transition temperature of the second polymer ranges from about 25°

C. to about 50°

C. greater than the first glass transition temperature of the first polymer.

4. The method of claim 1, wherein the support structure is printed to have a sprue hole;

and wherein the method further comprises depositing additional part material through the sprue hole after at least a portion of the three-dimensional part is cooled.

5. The method of claim 1, wherein the at least two polymers comprise a copolymer polymerized from monomers selected from the group consisting of acrylic acid, ionic salts of acrylic acid, methacrylic acid, ionic salts of methacrylic acid, alkyl acrylates, alkyl methacrylates, and combinations thereof.

6. The method of claim 1, wherein the printing of the support structure using the layer-based additive manufacturing technique and the printing of the three-dimensional part using the layer-based additive manufacturing technique are performed to provide layers for the support structure and the three-dimensional part having substantially the same layer thicknesses.

7. The method of claim 1, wherein the printing of the support structure and the printing of the three-dimensional part are performed in a build chamber of the extrusion-based additive manufacturing system, and wherein heating the printed support structure and the printed three-dimensional part is performed in the build chamber.

8. A method for building a three-dimensional part, the method comprising:

providing a three-dimensional part and a support structure, wherein the three-dimensional part is printed from a part material using a layer-based additive manufacturing technique, and wherein the support structure is printed from a support material in coordination with the three-dimensional part using the layer-based additive manufacturing technique, the support material comprising;

a first polymer having a first glass transition temperature; and

a second polymer that is substantially immiscible with the first polymer, the second polymer having a second glass transition temperature that is greater than the first glass transition temperature of the first polymer by at least about 10°

C.;

heating the provided three-dimensional part and the support structure to at least one temperature that is above a glass transition temperature of the part material, that is above the first glass transition temperature of the first polymer of the support material, and that is below the second glass transition temperature of the second polymer of the support material; and

cooling the heated three-dimensional part and the heated support structure.

9. The method of claim 8, wherein the second glass transition temperature of the second polymer is greater than the first glass transition temperature of the first polymer by at least about 20°

C.

10. The method of claim 9, wherein the second glass transition temperature of the second polymer ranges from about 25°

C. to about 50°

C. greater than the first glass transition temperature of the first polymer.

11. The method of claim 8, and further comprising maintaining the heating for a duration ranging from about 2 hours to about 5 hours.

12. The method of claim 8, wherein the second polymer comprises a copolymer polymerized from monomers selected from the group consisting of acrylic acid, ionic salts of acrylic acid, methacrylic acid, ionic salts of methacrylic acid, alkyl acrylates, alkyl methacrylates, and combinations thereof.

13. The method of claim 8, wherein the first polymer comprises a terpolymer having a plurality of carboxyl groups, a plurality of phenyl groups, and a plurality of carboxylate ester groups.

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

providing a support material to the extrusion-based additive manufacturing system, the support material comprising a first polymer having a first glass transition temperature and a second polymer that is substantially immiscible with the first polymer, and having a second glass transition temperature that is greater than the first glass transition temperature of the first polymer by at least about 10°

C.;

providing a part material to the extrusion-based additive manufacturing system, the part material having a glass transition temperature that is less than the second glass transition temperature of the second polymer of the support material;

heating a build environment of the extrusion-based additive manufacturing system to at least one temperature that is above the glass transition temperature of the part material, that is above the first glass transition temperature of the first polymer of the support material, and that is below the second glass transition temperature of the second polymer of the support material;

printing a support structure in the heated build environment from the support material in coordination with printing the three-dimensional part in the heated build environment from the part material; and

cooling the printed support structure and the printed three-dimensional part.

15. The method of claim 14, wherein the second glass transition temperature of the second polymer is greater than the first glass transition temperature of the first polymer by at least about 20°

C.

16. The method of claim 15, wherein the second glass transition temperature of the second polymer ranges from about 25°

C. to about 50°

C. greater than the first glass transition temperature of the first polymer.

17. The method of claim 14, and further comprising at least partially dissolving the cooled support structure in an aqueous alkaline solution.

18. The method of claim 14, wherein the second polymer comprises a copolymer polymerized from monomers selected from the group consisting of acrylic acid, ionic salts of acrylic acid, methacrylic acid, ionic salts of methacrylic acid, alkyl acrylates, alkyl methacrylates, and combinations thereof.