Selective deposition modeling build style providing enhanced dimensional accuracy

• US 6,936,212 B1
• Filed: 02/07/2002
• Issued: 08/30/2005
• Est. Priority Date: 02/07/2002
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Crawford, Clark W.
• Primary Examiner(s): Loney, Donald J.
• Application Number:
  US10/068,917
• Time in Patent Office: 1,300 Days
• Field of Search: 264/401, 264/308, 264/496, 264/227, 264/317, 264/497, 700/119, 700/120, 425/375, 425/449
• US Class Current: 264/308
• CPC Class Codes: B28B 1/00 Producing shaped prefabricated articles from the material using presses B28B3/00; shaping on moving conveyors B28B5/00; producing tubular articles B28B21/00 ; producing articles with embedded elements B28B23/00
• CPC Class Codes: B28B 1/001 Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00
• CPC Class Codes: B28B 17/0081 Process control
• CPC Class Codes: B29C 41/36 Feeding the material on to the mould, core or other substrate
• CPC Class Codes: B29C 41/48 Compensating volume change, e.g. retraction
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• 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 40/20 Post-treatment, e.g. curing, coating or polishing

Abstract

A method of forming a three-dimensional object in a layerwise manner is disclosed. The object is formed in a manner-that substantially prevents non-uniform distortion to occur during the layerwise build process as the build material forming the object solidifies and shrinks. The formed object comprises an outer surface defined by a shell structure and an internal lattice structure residing within the internal volume of the object. The object may be formed by any selective deposition modeling apparatus from a wide variety of materials.

Claims

1. A method of forming a three-dimensional object by selective deposition modeling from a solidifiable build material, the three-dimensional object having an outer surface defined by a shell structure of a desired dimensional configuration surrounding an internal volume of the object, the method comprising the steps of:

selectively dispensing the build material from at least one orifice in a flowable state to form layers of the object comprising the shell structure and an internal lattice structure formed in the areas of the layers that reside within the internal volume of the object, the internal lattice structure formed by dispensing the build material along a plurality of continuous segments that attach across the shell structure of the layer being formed for maintaining the desired dimensional configuration of the shell structure as it is formed; and

solidifying the dispensed material to a non-flowable state, the internal lattice structure substantially preventing the shell structure from non-uniformly deforming as the build material solidifies and shrinks.

2. The method of claim 1 wherein the internal lattice structure interconnects the shell structure in a X-direction, in a Y-direction, and in a Z-direction to maintain the desired dimensional configuration in all three-dimensions as the build material solidifies and shrinks.

3. The method of claim 1 wherein the plurality of continuous segments of the internal lattice structure forms a plurality of vertically extending supports.

4. The method of claim 3 wherein at least one of the vertically extending supports is a flat planar element.

5. The method of claim 3 wherein at least one of the vertically extending supports is a curved planar element.

6. The method of claim 3 wherein the vertically extending supports extend between upward facing surfaces and downward facing surfaces of the shell structure of the three-dimensional object and thereby establish a plurality of elongated compartments within the three-dimensional object.

7. The method of claim 6 further comprising the step of:

dispensing the build material to form post supports residing within said elongated compartments to provide support for upward facing surfaces of the shell structure of the three-dimensional object formed over said elongated compartments.

8. The method of claim 6 wherein the horizontal cross-sectional shape of said elongated compartments is polygonal.

9. The method of claim 1 further comprising the steps of:

providing computer data representing the three-dimensional object, the computer data comprising data representing the shell structure; and

processing the computer data to establish layer data for forming the layers of the object comprising the shell structure and internal lattice structure.

10. The method of claim 1 further comprising the step of:

providing the ability to enlarge the computer data with respect to the desired dimensional configuration of the three-dimensional object to account for linear shrinkage of the three-dimensional object as it is formed, the ability to enlarge the computer data provided the step of processing the computer data to establish layer data.

11. The method of claim 1 wherein the build material is a phase change material solidified by lowering the temperature of the build material after it has been dispensed.

12. The method of claim 1 wherein the build material is a powder and is solidified by selectively dispensing a binder that reacts with the powder to cure the powder to form the shell structure and the internal lattice structure.

25. The method of claim 1 further comprising dispensing the build material from an print head or a nozzle.

13. A method of forming a three-dimensional object by selective deposition modeling from a build material curable upon exposure to actinic radiation, the three-dimensional object having an outer surface defined by a shell structure of a desired dimensional configuration, the method comprising the steps of:

selectively dispensing the curable build material from at least one orifice in a flowable state to form layers of the object comprising the shell structure and an internal lattice structure in the areas of the layers that reside within the internal volume of the object, the internal lattice structure formed by dispensing the build material along a plurality of continuous segments that attach across the shell structure of the layer being formed for maintaining the desired dimensional configuration of the shell structure as it is formed;

solidifying the dispensed material to a non-flowable state, the internal lattice structure substantially preventing the shell structure from non-uniformly deforming as the build material solidifies and shrinks; and

curing the dispensed layers of build material after the dispensed build material has solidified.

14. The method of claim 13 wherein the internal lattice structure interconnects the shell structure in a X-direction, in a Y-direction, and in a Z-direction to maintain the desired dimensional configuration in all three dimensions as the build material solidifies and shrinks.

15. The method of claim 13 further comprising the steps of:

providing computer data representing the three-dimensional object, the computer data comprising data representing the shell structure; and

processing the computer data to establish layer data for forming the layers of the object comprising the shell structure and internal lattice structure.

16. The method of claim 15 further comprising the step of:

providing the ability to enlarge the computer data with respect to the desired dimensional configuration of the three-dimensional object to account for linear shrinkage of the three-dimensional object as it is formed, the ability to enlarge the computer data provided before the step of processing the computer data to establish layer data.

17. The method of claim 13 further comprising the steps of:

dispensing a support material in a flowable state to support the shell structure of the three-dimensional object;

solidifying the dispensed support material to a non-flowable state; and

removing at least some of the support material from the three-dimensional object after the three-dimensional object has been formed.

18. The method of claim 17 wherein the plurality of continuous segments of the internal lattice structure form a plurality of vertically extending supports.

19. The method of claim 18 wherein at least one of the vertically extending supports is a flat planar element.

20. The method of claim 18 wherein at least one of the vertically extending supports is a curved planar element.

21. The method of claim 18 wherein the vertically extending supports extend between upward facing surfaces and downward facing surfaces of the shell structure of the three-dimensional object and thereby establish a plurality of elongated compartments within the three-dimensional object.

22. The method of claim 21 wherein the support material is dispensed into each elongated compartment to provide support for upward facing surfaces of the shell structure of the three-dimensional object formed over said elongated compartments.

23. The method of claim 21 wherein the horizontal cross-sectional shape of said elongated compartments is polygonal.

24. The method of claim 21 wherein the elongated compartments are interconnected and the method further comprising the steps of:

providing a drainage opening in the shell structure; and

removing the support material from the elongated compartments after three-dimensional object has been formed.

26. The method of claim 13 further comprising dispensing the build material from an print head or a nozzle.

27. A method of forming a three-dimensional object by selective deposition modeling from a solidifiable build material, the three dimensional object having an outer surface defined by a shell structure of a desired dimensional configuration, the method comprising the steps of:

selectively dispensing the build material in a flowable stale to form layers of the object comprising the shell structure and an internal lattice structure in the areas of the layers that reside within the internal volume of the object, the internal lattice structure formed by dispensing the build material along a plurality of continuous segments that attach across the shell structure of the layer being formed for maintaining the desired dimensional configuration of the shell structure as it is formed and forming a plurality of vertically extending supports at least one which is a curved planar element; and

solidifying the dispensed material to a non-flowable state, the internal lattice structure substantially preventing the shell structure from non-uniformly deforming as the build material solidifies and shrinks.

28. The method of claim 27 wherein the build material is curable upon exposure to actinic radiation.