Three-Dimensional Parts Having Porous Protective Structures

• US 20120018926A1
• Filed: 02/03/2011
• Published: 01/26/2012
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Mannella, Dominic F., Zinniel, Robert L., Crump, S. Scott
• Granted Patent: US 8,221,858 B2
• Time in Patent Office: Days
• US Class Current: 264/500
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29C 64/171 specially adapted for manufacturing multiple 3D objects
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 40/20 Post-treatment, e.g. curing, coating or polishing
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/15 Sheet, web, or layer weakened to permit separation through thickness
• CPC Class Codes: Y10T 428/239 Complete cover or casing

Abstract

Three-dimensional parts having porous protective structures built with powder-based additive manufacturing systems, the porous protective structures being configured to protect the three-dimensional parts from damage during de-powdering processes.

Claims

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

receiving a digital representation of the three-dimensional part;

generating a digital representation of a of a porous structure comprising;

a digital representation of a porous outer frame for the three-dimensional part; and

a digital representation of at least one extension between the porous outer frame and the three-dimensional part, wherein the at least one extension is configured to operably tether the three-dimensional part within the porous outer frame; and

generating layer-based tool paths for building the building the three-dimensional part in a powder-based, additive manufacturing system, the layer-based tool paths being generated based at least in part on the digital representation of the three-dimensional part and the digital representation of the porous structure.

2. The method of claim 1, wherein the digital representation of the at least one extension is configured to rigidly connect the three-dimensional part to the porous outer frame.

3. The method of claim 1, wherein the digital representation of the porous structure further comprises a digital representation of a porous shell that at least partially encases the three-dimensional part, wherein the digital representation of the at least one extension is configured to rigidly connect the porous shell to the porous outer frame.

4. The method of claim 3, wherein generating the digital representation of the porous shell comprises determining at least one offset distance from the three-dimensional part, the at least one offset distance ranging from about 0.01 inches to about 0.10 inches.

5. The method of claim 1, and further comprising:

forming a layer of a powder material in a build chamber of the powder-based additive manufacturing system;

solidifying portions of the powder material based on at least a portion of the generated layer-based tool paths to build the three-dimensional part in a bed of unbound powder material; and

removing at least a portion of the unbound powder material from the three-dimensional part.

6. The method of claim 5, wherein removing the portion of the unbound powder material from the three-dimensional part comprises generating an air flow around the three-dimensional part and the porous structure sufficient to move the porous structure.

7. The method of claim 5, and further comprising removing the porous structure from the three-dimensional object after removing the portion of the unbound powder material from the three-dimensional part.

8. A method for removing unbound powder materials from a three-dimensional part, the method comprising:

providing a chamber containing a three-dimensional part operably tethered to a porous structure, wherein the three-dimensional part and the porous structure are built from a powder-based additive manufacturing system with a powder material; and

generating an air flow around the three-dimensional part and the porous structure that is sufficient to remove substantially all unbound powder materials from the three-dimensional part.

9. The method of claim 8, wherein generating an air flow comprises an action selected from the group consisting of directing compressed air to the three-dimensional part, generating a vacuum, and a combination thereof.

10. The method of claim 8, and further comprising moving the three-dimensional part and the porous structure with the generated air flow at a sufficient velocity to damage at least a portion of the porous structure.

11. The method of claim 8, and further comprising building the three-dimensional and the porous structure in the chamber with the powder-based additive manufacturing system.

12. The method of claim 11, wherein building the three-dimensional and the porous structure comprises:

delivering layer of the powder material to a build chamber of the powder-based additive manufacturing system; and

solidifying portions of the powder material based on layer-based tool paths.

13. The method of claim 8, wherein the porous structure comprises:

a porous outer frame; and

at least one extension connected to the porous outer frame and operably tethering the three-dimensional part within the porous outer frame.

14. A three-dimensional assembly built with a powder-based, digital manufacturing system, the three-dimensional assembly comprising:

a three-dimensional part based at least in part on a digital representation of the three-dimensional part; and

a porous structure configured to protect the three-dimensional part during a de-powdering process, the porous structure comprising;

a porous outer frame; and

at least one extension connected to the porous outer frame and operably tethering the three-dimensional part within the porous outer frame.

15. The three-dimensional assembly of claim 14, wherein the at least one extension is rigidly connected to the three-dimensional part to operably tether the three-dimensional part within the porous outer frame.

16. The method of claim 15, wherein the porous structure further comprises a porous shell that at least partially encases the three-dimensional part, wherein the at least one extension is connected the porous shell to operably tether the three-dimensional part within the porous outer frame.

17. The method of claim 16, wherein the porous shell is offset from the three-dimensional object by an average offset distance ranging from about 0.01 inches to about 0.10 inches.

18. A system for building a three-dimensional part, the system comprising:

a build chamber;

a powder delivery system configured to deliver powder materials to the build chamber;

a tool head configured to solidify portions of the delivered powder materials to form layers of the three-dimensional part and layers of a porous structure; and

an automated powder removal system configured to remove unbound powder materials from the build chamber, wherein the porous structure is configured to protect the three-dimensional part from damage during a de-powdering process.

19. The system of claim 18, wherein the automated powder removal system is configured to generate an air flow around the three-dimensional part and the porous structure that is sufficient to move the three-dimensional part and the porous structure.

20. The system of claim 18, wherein the tool head comprises a jetting head configured to deposit at least one binder material.