METHOD OF REDUCING THE FORCE REQUIRED TO SEPARATE A SOLIDIFIED OBJECT FROM A SUBSTRATE

• US 20100262272A1
• Filed: 04/14/2009
• Published: 10/14/2010
• Est. Priority Date: 04/14/2009
• Status: Active Grant

• Current Assignee: Gulf Filtration Systems Inc. (Desktop Metal, Inc.)
• Original Assignee: Gulf Filtration Systems Inc. (Desktop Metal, Inc.)
• Inventors: El-Siblani, Ali, Shkolnik, Alexandr
• Granted Patent: US 8,326,024 B2
• Time in Patent Office: Days
• US Class Current: 700/120
• CPC Class Codes: B29C 33/68 Release sheets
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• 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 50/02 for controlling or regulating additive manufacturing processes

Abstract

A method and apparatus for making a three-dimensional object from a solidifiable material such as a photopolymer is shown and described. In accordance with the method, positions relative to a build axis are subdivided into first and second exposure data subsets, and the first and second exposure data subsets are solidified in alternating sequences to reduce the surface area of solidified material in contact with a solidification substrate.

Claims

1. A method of forming a three-dimensional object from an object representation having a build axis dimension, the method comprising:

providing a set of object data corresponding to a plurality of locations in the object, each location corresponding to a position along a build axis dimension and a position relative to the build axis dimension;

subdividing the set of object data into a first exposure data subset and a second exposure data subset, wherein the first exposure data subset defines a first subset of positions relative to the build axis, and the second exposure data subset defines a second subset of positions relative to the build axis;

providing a first exposure surface of a solidifiable material; and

solidifying only the first subset of positions on a first exposed surface of solidification material without solidifying the second subset of positions.

2. The method of claim 1, further comprising:

providing a second exposure surface of the solidifiable material; and

solidifying the second subset of positions on the second exposed surface of solidifiable material without solidifying the first subset of locations on the second exposed surface of solidifiable material.

3. The method of claim 2, further comprising:

providing a third exposure surface of the solidifiable material; and

solidifying the first subset of positions on the third exposure surface without solidifying the second subset of positions on the third exposure surface.

4. The method of claim 1, wherein the set of object data comprises a plurality of voxels.

5. The method of claim 1, wherein the of object data comprises bitmap data.

6. The method of claim 1, further comprising providing a digital light projector, wherein the step of solidifying only the first subset of positions on the first exposed surface of the solidification material comprises projecting light from the digital light projector onto the first subset of positions on the first exposed surface of the solidification material.

7. The method of claim 1, further comprising:

providing a solidification substrate; and

supplying a first volume of the solidifiable material adjacent the solidification substrate to create the first exposed surface of the solidifiable material.

8. The method of claim 7, wherein the solidification substrate comprises a film.

9. The method of claim 7, further comprising providing a solidifiable material container containing the solidifiable material and a build platform disposed within the container, wherein the step of supplying a first volume of the solidifiable material adjacent the solidification substrate comprises moving the build platform away from the solidification substrate.

10. The method of claim 9, further comprising a build platform for supporting or suspending the object as the object is built, wherein during an object build operation, one selected from the solidification substrate and the build platform continuously moves away from the other of the solidification substrate and the build platform.

11. The method of claim 1, wherein the set of object data includes a maximum incremental object thickness along the build axis dimension.

12. The method of claim 11, wherein the step of solidifying only the first subset of positions on the first exposed surface of solidification material comprises solidifying the first subset of positions on the first exposed surface to a depth that is substantially equal to the maximum incremental object thickness.

13. The method of claim 11, wherein the step of solidifying only the first subset of positions on the first exposed surface of solidification material comprises solidifying the first subset of positions on the first exposed surface to a depth greater than the maximum incremental object thickness along the build axis dimension.

14. The method of claim 13, wherein the depth greater than the maximum incremental object thickness is twice the maximum incremental object thickness.

15. The method of claim 1, wherein the first subset of positions relative to the build axis and the second subset of positions relative to the build axis define an alternating sequence of first subset members and second subset members.

16. The method of claim 15, wherein the alternating sequence comprises a first alternating sequence in a first direction and a second alternating sequence in a second direction.

17. The method of claim 15, wherein the alternating sequence comprises rows of first exposure data subset members adjacent to rows of second exposure data subset members.

18. The method of claim 1, wherein the step of solidifying only the first subset of positions on the first exposed surface of solidification material comprises partially solidifying the first exposed surface in contact with the solidification substrate, and the method further comprises separating the partially solidified first exposed surface from the solidification substrate.

19. The method of claim 18, further comprising supplying the solidification material between the partially solidified, separated first exposed surface of the solidification material and the solidification substrate.

20. The method of claim 1, further comprising:

providing a second exposed surface of solidifiable material;

solidifying the second subset of positions on the second exposed surface to a first depth, and solidifying the first subset of positions to a second depth.

21. The method of claim 20, wherein the first depth is substantially twice the second depth.

22. The method of claim 1, wherein the solidification material comprises a photopolymer.

23. The method of claim 1, wherein the solidification substrate comprises a translucent glass layer.

24. The method of claim 1, wherein the solidification substrate comprises a translucent, resilient layer.

25. The method of claim 23, wherein the solidification material comprises a protective film.

26. An apparatus for producing a three-dimensional object from a solidifiable material, comprising:

a pattern generator having an energy projection region;

a build platform movable along the direction of a build axis and positioned in the energy projection region; and

at least one computer having a processor and a computer-readable memory with instructions programmed thereon for performing the following steps;

subdividing a set of object data into a first exposure data subset and a second exposure data subset, wherein the first exposure data subset defines a first subset of positions relative to the build axis, and the second exposure data subset defines a second subset of positions relative to the build axis;

determining a solidification depth from an exposed surface of the solidifiable material for the first exposure data subset; and

directing the supply of solidification energy from the pattern generator to solidify the first subset of positions on a first exposed surface to the solidification depth without solidifying the second subset of positions.

27. The apparatus of claim 26, wherein the at least one computer is further programmed to receive a maximum incremental object thickness of an object representation, and the solidification depth is greater than the maximum incremental object thickness.

28. The apparatus of claim 26, wherein the at least one computer comprises a control computer configured to communicate the first exposure data subset to the pattern generator.

29. The apparatus of claim 26, further comprising a translucent solidification substrate disposed between the pattern generator and the build platform.

30. The apparatus of claim 26, wherein the pattern generator is a digital light projector.

31. The apparatus of claim 26, further comprising a moving film and a source of the solidifiable material, wherein when the film advances, a volume of the solidifiable material is applied to the film and enters the energy projection region of the pattern generator.

32. The apparatus of claim 26, further comprising a solidifiable material container, wherein the solidifiable material is disposed in the solidifiable material container.

33. The apparatus of claim 32, wherein the build platform is disposed in the solidifiable material container.

34. The apparatus of claim 26, wherein the exposure data is voxel data.

35. A method of forming a three-dimensional object from an object representation by solidifying a solidifiable material along a build axis to define a build axis dimension in the three-dimensional object, the method comprising:

solidifying a first set of regions on a first exposed surface of a solidifiable material without solidifying a second set of regions of the solidifiable material; and

solidifying the second set of regions on a second exposed surface of the solidifiable material without solidifying the first set of regions, wherein the first set of regions define a first set of positions relative to the build axis dimension, and the second set of regions define a second set of positions relative to the build axis dimension.

36. The method of claim 35, wherein the first set of regions is solidified to a first depth from the first exposed surface, the second set of regions is solidified to a second depth from the second exposed surface, and the second depth is greater than the first depth.

37. The method of claim 36, wherein the second depth is twice the first depth.

38. The method of claim 35, wherein the object representation comprises voxel data.

39. The method of claim 35, further comprising providing a build platform that is movable along the build axis during an object building operation, wherein the first exposed surface defines a first distance from the build platform, and the second exposed surface defines a second distance from the build platform.