Process and freeform fabrication system for producing a three-dimensional object

• US 20090130449A1
• Filed: 10/24/2008
• Published: 05/21/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Envisiontec GmbH (Desktop Metal, Inc.)
• Original Assignee: Envisiontec GmbH (Desktop Metal, Inc.)
• Inventors: El-Siblani, Ali
• Granted Patent: US 8,110,135 B2
• Time in Patent Office: Days
• US Class Current: 428/409
• CPC Class Codes: A61C 13/0013 using stereolithographic techniques
• CPC Class Codes: B29C 64/129 characterised by the energy source therefor, e.g. by global irradiation combined with a mask
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: Y10T 428/31 Surface property or characteristic of web, sheet or block

Abstract

The present invention describes a process for producing a three-dimensional object, comprising: providing a material to be solidified, the material comprising a filler and a binder; delivering electromagnetic radiation and/or synergistic stimulation in a pattern or an image to a building region for solidifying said material; wherein said delivering of electromagnetic radiation and/or synergistic stimulation is performed selectively to a defined area or volume of said material to be solidified; and wherein an energy density of electromagnetic radiation and/or synergistic stimulation is varied within said pattern or image and/or between patterns or images of different building regions of said material. The present invention may be directed also to a system where different first and second materials are to be solidified. The present invention further provides a freeform fabrication system, and a freeform three-dimensional object having unique properties as well as products derived therefrom, such as sintered products.

Claims

1. A process for producing a three-dimensional object, comprising:

providing a material to be solidified, the material comprising a filler and a binder;

delivering electromagnetic radiation or synergistic stimulation in a pattern or an image to a building region for solidifying said material;

wherein said delivering of electromagnetic radiation and/or synergistic stimulation is performed selectively to a defined area or volume of said material to be solidified; and

wherein an energy density of electromagnetic radiation or synergistic stimulation is at least partially varied within said pattern or image, or varied between patterns or images of different building regions of said material.

2. The process according to claim 1, wherein providing a material includes

providing a first material to be solidified for generating at least a part of a desired three-dimensional object structure, the material comprising a filler and a binder, and

providing a second material, different from said first material, to be solidified as another part of the desired three-dimensional object structure or as an auxiliary support structure;

wherein delivering electromagnetic radiation or synergistic stimulation includes solidifying said first and second materials by means of the electromagnetic radiation or synergistic stimulation delivered selectively to respectively defined areas or volumes of said first and second materials; and

wherein, instead of varying within the pattern or image or varying between patterns or images of different building regions of the same material, energy densities of electromagnetic radiation or synergistic stimulation are at least partially varied between areas or volumes of said respectively defined first and second materials for solidification.

3. The process according to claim 1, wherein said selective delivery of electromagnetic radiation or synergistic stimulation comprises using a mask or a projection unit to deliver the electromagnetic radiation or synergistic stimulation selectively to the defined area or volume of material to be solidified.

4. The process according to claim 1, wherein said variation of intensity of electromagnetic radiation or synergistic stimulation is performed by at least one of:

(a) exposure times varied in XY or in Z;

(b) number of multiple used patterns or images;

(c) gradation of energy intensity in one or more patterns or images;

(d) location of focal plane or focal point within the building region; and

(e) applying a second source or a second delivery of second electromagnetic or synergistic radiation.

5. The process according to claim 1, wherein said selective delivery of electromagnetic radiation or synergistic stimulation is based on an imaging unit comprising a predetermined number of discrete imaging elements or pixels;

and wherein the variation of intensity of energy is performed by controlling a gray value or a color value of at least a part of the pixels.

6. The process according to claim 1, wherein said variation of intensity of electromagnetic radiation or synergistic stimulation is controlled by a control unit depending on at least one of following criteria, respectively applied alone or in combination:

(i) type, size or amount of filler contained in the material to be solidified;

(ii) type or amount of binder contained in the material to be solidified;

(iii) hardening depth;

(iv) presence or absence of underlying solidified, filler-containing material;

(v) size of the defined area or volume of said material to be solidified;

(vi) delivery of electromagnetic radiation or synergistic stimulation to area regions or to boundary regions of the three-dimensional object to be formed;

(vii) viscosity or flowability of the material to be solidified; and

(viii) pressure or strain occurring in or at the building region during solidification of the material.

7. The process according to claim 1, wherein said filler comprises ceramic particles.

8. The process according to claim 7, wherein said ceramic particles are selected from alumina particles or powders or zirconia particles or powders, or a mixture thereof.

9. The process according to claim 7, wherein said ceramic particles are powders of yttria stabilized tetragonal zirconia (YTZP), with or without a sintering additive or dispersion agent.

10. The process according to claim 1, wherein said filler is a powder or particles having a mean particle size in the range of about 0.1 nm to about 100 μ

m.

11. The process according to claim 1, wherein said binder is selected from the group consisting of photopolymers and adhesives.

12. The process according to claims 1, wherein said filler is contained in an amount of about 10% by weight to about 99% by weight of the total material to be solidified.

13. The process according to claim 1, wherein the binder of said material to be solidified comprises an adhesive which allows two or more layers, or other multiple structural parts of filler containing composite material to be successively attached together.

14. The process according to claim 1, wherein the three-dimensional object as produced is subjected to a post-treatment selected from post-hardening, de-binding, or sintering.

15. The process according to claim 1, wherein the three-dimensional object after solidifying the material has a first circumferential size in an untreated state and has a second circumferential size in a post-treated state, in particular in a sintered state, wherein said first circumferential size is larger than said second circumferential size.

16. The process according to claim 1, wherein the produced three-dimensional object is a dental product or a part of a dental product.

17. The process according to claim 1, wherein the three-dimensional object is built on an object carrier or support, wherein said object carrier or support is moved upward as the built three-dimensional object grows.

18. The process according to claim 1, wherein the material to be solidified is provided in the building region on a transparent film at the stage of delivering electromagnetic radiation or synergistic stimulation.

19. The process according to claim 1, wherein the material to be solidified comprises a photocurable resin as said binder.

20. The process according to claim 1, wherein the binder comprises a first binder substance and a second binder substance, and the first binder substance comprises a photocurable resin.

21. The process according to claim 1, wherein the material to be solidified is conveyed from a resin source to the building region on a movable film.

22. The process according to claim 21, wherein a mask projector is disposed below the film to project an image through the film.

23. The process according to claim 22, wherein the mask projector is a digital light projector.

24. The process according to claim 1, wherein the three-dimensional object is built on a object carrier or support placed above a device for delivering electromagnetic radiation or synergistic stimulation, and a transparent plate is disposed between said transparent object carrier or support and said radiation or synergistic stimulation delivery device.

51. A freeform three-dimensional object formed from a solidifiable material comprising a filler and a binder by electromagnetic radiation or synergistic stimulation, the object being obtained by a process according to claim 1.

52. The freeform three-dimensional object according to claim 51, which is in a sintered form.

25. A process for producing a three-dimensional object, comprising:

providing a material to be solidified, the material comprising a filler and a photocurable resin as a binder;

delivering electromagnetic radiation or synergistic stimulation in a pattern or an image to a building region for solidifying said material;

wherein said delivering of electromagnetic radiation or synergistic stimulation is performed selectively to a defined area or volume of said material to be solidified by using a mask projector; and

wherein the three-dimensional object is built on an object carrier or support, and wherein said object carrier or support is moved upward as the built three-dimensional object grows; and

wherein the material to be solidified is conveyed from a resin source to the building region on a movable film.

26. The process according to claim 25, wherein said mask projector is a digital light projector.

27. The process according to claim 25, wherein said movable film is transparent.

28. A freeform fabrication system, comprising:

a material to be solidified, the material comprising a filler and a binder;

a electromagnetic radiation or synergistic stimulation delivery device capable of delivering electromagnetic radiation or synergistic stimulation in a pattern or an image to a building region for solidifying said material;

wherein said electromagnetic radiation or synergistic stimulation delivery device is designed to selectively deliver electromagnetic radiation or synergistic stimulation to a defined area or volume of said material to be solidified; and

wherein an energy density of electromagnetic radiation or synergistic stimulation is at least partially varied within said pattern or image, or varied between patterns or images of different building regions of said material.

29. The freeform fabrication system according to claim 28, further comprising an object carrier or support, which is movable upward or downward, or movable both upward and downward.

30. The freeform fabrication system according to claim 28, further comprising a film transparent to the delivery of electromagnetic radiation or synergistic stimulation, wherein said material to be solidified is disposed on said transparent film.

31. The freeform fabrication system according to claim 28, wherein the material to be solidified comprises a photocurable resin as said binder.

32. The freeform fabrication system according to claim 28, wherein the binder comprises a first binder substance and a second binder substance, and the first binder substance comprises a photocurable resin.

33. The freeform fabrication system according to claim 28, further comprising a conveyor system for conveying the material to be solidified from a material source to the building region on a movable film.

34. The freeform fabrication system according to claim 28, wherein said electromagnetic radiation or synergistic stimulation delivery device comprises a mask projector.

35. The freeform fabrication system according to claim 34, wherein said mask projector is disposed below a film to project an image through the film, wherein said material to be solidified is provided on said film.

36. The freeform fabrication system according to claim 34, wherein the mask projector is a digital light projector.

37. The freeform fabrication system according to claim 28, further comprising:

an object carrier or support on which a three-dimensional object is built;

said object carrier or support being disposed above said radiation or synergistic stimulation delivery device; and

a transparent plate disposed between said object carrier or support and said radiation or synergistic stimulation delivery device.

38. The freeform fabrication system according to claim 28,

wherein said material to be solidified includes a first material to be solidified for generating at least a part of a desired three-dimensional object structure, the material comprising a filler and a binder;

and a second material, different from said first material, to be solidified as another part of the desired three-dimensional object structure or as an auxiliary support structure;

wherein said electromagnetic radiation or synergistic stimulation delivery device is capable of delivering electromagnetic radiation or synergistic stimulation selectively to defined areas or volumes of said first and second materials, respectively; and

wherein, instead of varying within the pattern or image or between patterns or images of different building regions of the same material, energy densities of electromagnetic radiation or synergistic stimulation is at least partially varied between said respectively defined areas or volumes of said first and second materials for solidification.

39. A freeform fabrication system, comprising:

a material to be solidified, the material comprising a filler and a binder;

a electromagnetic radiation or synergistic stimulation delivery device capable of delivering electromagnetic radiation or synergistic stimulation which allows an additive generation of a three-dimensional object by successive solidification of said material;

wherein said electromagnetic radiation or synergistic stimulation delivery device is based on a mask exposure system or a projection system.

40. The freeform fabrication system according to claim 39, wherein said electromagnetic radiation or synergistic stimulation delivery device is respectively set or controlled by a previous setting or by a control unit depending on at least one of following criteria, respectively applied alone or in combination:

(i) type, size or amount of filler contained in the material to be solidified;

(ii) type or amount of binder contained in the material to be solidified;

(iii) hardening depth;

(iv) presence or absence of underlying solidified, filler-containing material;

(v) size of the defined area or volume of said material to be solidified;

(vi) delivery of electromagnetic radiation or synergistic stimulation to area regions or to boundary regions of the three-dimensional object to be formed;

(vii) viscosity or flowability of the material to be solidified; and

(viii) pressure or strain occurring in or at the building region during solidification of the material.

41. The freeform fabrication system according to claim 39, further comprising

an object carrier or support, which is movable upward or downward, or movable both upward and downward.

42. The freeform fabrication system according to claim 39, further comprising a film transparent to the delivery of electromagnetic radiation or synergistic stimulation, wherein said material to be solidified is disposed on said transparent film.

43. The freeform fabrication system according to claim 39, wherein the material to be solidified comprises a photocurable resin as said binder.

44. The freeform fabrication system according to claim 39, wherein the binder comprises a first binder substance and a second binder substance, and the first binder substance comprises a photocurable resin.

45. The freeform fabrication system according to claim 39, further comprising a conveyor system for conveying the material to be solidified from a material source to a building region in a manner supported by a film.

46. The freeform fabrication system according to claim 39, wherein said electromagnetic radiation or synergistic stimulation delivery device comprises a mask projector.

47. The freeform fabrication system according to claim 46, wherein said mask projector is disposed below a film to project an image through the film, wherein said material to be solidified is provided on said film.

48. The freeform fabrication system according to claim 46, wherein the mask projector is a digital light projector.

49. The freeform fabrication system according to claim 39, further comprising:

an object carrier or support on which a three-dimensional object is built;

said object carrier or support being disposed above said radiation or synergistic stimulation delivery device; and

a transparent plate disposed between said object carrier or support and said radiation or synergistic stimulation delivery device.

50. A freeform fabrication system, comprising:

a material to be solidified, the material comprising a filler and a photopolymer resin;

a electromagnetic radiation or synergistic stimulation delivery device based on a mask exposure system or a projection system, capable of selectively delivering electromagnetic radiation or synergistic stimulation in a pattern or an image to a building region for solidifying said material;

an object carrier or support movable upward or downward; and

a conveyor system for conveying the material to be solidified from a material source to the building region on a movable film.