Inorganic ionic support materials for digital manufacturing systems

• US 8,245,757 B2
• Filed: 02/02/2010
• Issued: 08/21/2012
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Crump, S. Scott, Batchelder, J. Samuel, Sampson, Timothy, Barnett, John
• Primary Examiner(s): Gupta, Yogendra
• Assistant Examiner(s): HINDENLANG, ALISON L
• Application Number:
  US12/698,528
• Publication Number:
  US 20100193998A1
• Time in Patent Office: 931 Days
• Field of Search: 106/286.6, 106/286.7, 164/15
• US Class Current: 164/15
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/385 Overhang structures
• CPC Class Codes: B22F 10/47 characterised by structural features
• CPC Class Codes: B22F 12/222 for motion along a direction orthogonal to the plane of a layer
• CPC Class Codes: B22F 12/224 for motion along a direction within the plane of a layer
• CPC Class Codes: B22F 12/38 Housings, e.g. machine housings
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• 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
• CPC Class Codes: C23C 26/02 applying molten material to the substrate
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A support material for use with a digital manufacturing system, the support material comprising at least one inorganic ionic compound and is configured to be deposited with the digital manufacturing system using a layer-based additive technique to form a support structure for supporting at least one overhanging region of a three-dimensional model built with the digital manufacturing system.

Claims

1. A method for building a three-dimensional model with a digital manufacturing system, the method comprising:

heating a build chamber of the digital manufacturing system to maintain one or more temperatures of at least about 200°

C.;

melting a support material in an extrusion head of the digital manufacturing system to an extrudable state, wherein the support material comprises a non-eutectic blend of a first inorganic alkali-metal salt and a second inorganic alkali-metal salt;

extruding the molten support material from the extrusion head;

depositing the extruded support material into the heated build chamber using a first layer-based additive technique to form a support structure; and

depositing a modeling material into the heated build chamber using a second layer-based additive technique to form the three-dimensional model, wherein the three-dimensional model comprises at least one overhanging region supported by the support structure.

2. The method of claim 1, wherein the first inorganic alkali-metal salt comprises lithium chloride.

3. The method of claim 1, wherein heating the build chamber comprises heating the build chamber to maintain one or more temperatures ranging from about 400°

C. to about 700°

C.

4. The method of claim 1, wherein the support material has an average creep relaxation temperature that is within about 30°

C. of a creep relaxation temperature of the modeling material.

5. The method of claim 1, and further comprising removing at least a portion of the support structure from the three-dimensional model by dissolving the portion of the support structure in a liquid.

6. The method of claim 1, and further comprising substantially purging the build chamber of oxidizing gases.

7. The method of claim 1, wherein the second inorganic alkali-metal salt comprises potassium chloride.

8. The method of claim 1, wherein the non-eutectic blend constitutes from about 75% by weight to 100% by weight of the support material.

9. The method of claim 1, and further comprising recycling at least a portion of the deposited support material.

10. A method for building a three-dimensional model with a digital manufacturing system, the method comprising:

heating a build chamber of the digital manufacturing system to maintain one or more temperatures of at least about 200°

C.;

melting a support material in an extrusion head of the digital manufacturing system to an extrudable state, wherein the support material comprises a non-eutectic blend of a first alkali-metal salt and a second alkali-metal salt, and wherein the support material is substantially free of organic compounds;

extruding the molten support material from the extrusion head;

depositing the extruded support material into the heated build chamber using a first layer-based additive technique to form a support structure; and

depositing a modeling material into the heated build chamber using a second layer-based additive technique to form the three-dimensional model, wherein the three-dimensional model comprises at least one overhanging region supported by the support structure.

11. The method of claim 10, wherein the first alkali-metal salt comprises lithium chloride.

12. The method of claim 10, wherein heating the build chamber comprises heating the build chamber to maintain one or more temperatures ranging from about 400°

C. to about 700°

C.

13. The method of claim 10, wherein the second alkali-metal salt comprises potassium chloride.

14. The method of claim 10, wherein the non-eutectic blend constitutes from about 75% by weight to 100% by weight of the support material.

15. A method for building a three-dimensional model with a digital manufacturing system, the method comprising:

heating a build chamber of the digital manufacturing system to maintain one or more temperatures ranging from about 400°

C. to about 700°

C.;

melting a support material in an extrusion head of the digital manufacturing system to an extrudable state, wherein the support material comprises a non-eutectic blend of potassium chloride and lithium chloride;

extruding the molten support material from the extrusion head;

depositing the extruded support material into the heated build chamber using a first layer-based additive technique to form a support structure; and

depositing a modeling material into the heated build chamber using a second layer-based additive technique to form the three-dimensional model, wherein the three-dimensional model comprises at least one overhanging region supported by the support structure, and wherein the modeling material comprises a metal-based material.

16. The method of claim 15, wherein the potassium chloride constitutes from about 60% by weight to about 99% by weight of the non-eutectic blend.

17. The method of claim 16, wherein the potassium chloride constitutes from about 70% by weight to about 95% by weight of the non-eutectic blend.

18. The method of claim 15, wherein the metal-based material of the modeling material comprises a non-eutectic, metal-based alloy.

19. The method of claim 15, wherein the lithium chloride constitutes from about 50% to about 99% of the non-eutectic blend.

20. The method of claim 15, wherein the lithium chloride constitutes from about 65% to about 90% of the non-eutectic blend.