Mold shape deposition manufacturing

• US 6,375,880 B1
• Filed: 09/30/1998
• Issued: 04/23/2002
• Est. Priority Date: 09/30/1997
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Kietzman, John W., Cooper, Alexander G., Prinz, Friedrich B.
• Primary Examiner(s): Kuhns, Allan R.
• Application Number:
  US09/164,415
• Time in Patent Office: 1,301 Days
• Field of Search: 264/219, 264/221, 264/344, 264/313, 264/317, 264/318, 264/138
• US Class Current: 264/138
• CPC Class Codes: B29C 2793/009 after shaping
• CPC Class Codes: B29C 33/3842 Manufacturing moulds, e.g. shaping the mould surface by machining
• CPC Class Codes: B29C 33/52 soluble or fusible in particular used in injection moulding B29C45/4457
• CPC Class Codes: B29C 64/124 using layers of liquid which are selectively solidified
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B29L 2031/757 Moulds, cores, dies
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing

Abstract

A method of making molded parts employing Shape Deposition Manufacturing (SDM) techniques. First, SDM processes are used to make a layered structure having support segments and mold segments. The support segments are made of material which may be removed from the mold segments (e.g. dissolved or melted). The mold segments are made of a material which can function as a mold. The mold and support segments are sequentially deposited (e.g. in layers) and shaped (e.g. machined) to form a mold. The support segments define the shape of the part to be manufactured. The mold segments are removed from the support segments by dissolving or melting away the support segments, leaving an empty mold. Then, part material is cast into the empty mold. The mold is removed, providing a molded part. The part material can be a gelcasting slurry, for example. The present method provides homogeneous or heterogeneous parts having shapes which are accurately defined by the SDM process.

Claims

1. A method of making a complex three-dimensional molded part, comprising the steps of:

a) generating a mold by

(i) sequentially depositing in a predetermined deposition fashion a plurality of mold layers each comprising mold material, at least one of said mold layers comprising a mold segment formed of said mold material and a support segment formed of support material, wherein said mold material being removing resistant against a first removing means and being removable by a second removing means, wherein said support material being removable by said first removing means;

(ii) shaping a mold surface within a previously deposited mold layer of said plurality of mold layers by shaping at least one of said support segment and said mold segment prior to deposition of a subsequent mold layer above said support segment and said mold segment, said shaping including three dimensional material removal in correspondence with a predetermined configuration of said mold surface, said predetermined configuration being independent of said predetermined deposition fashion, and wherein said predetermined deposition fashion and said shaping provide final layers selected from the group consisting of;

A) planar layers;

B) non planar layers;

C) wedge shaped layers;

D) layers having an uneven thickness;

E) layers having an undulating thickness;

F) layers having a curved shape; and

G) layers having different thicknesses;

(iii) removing said support material from said mold by removing said support material by use of said first removing means;

b) casting part material into said mold to produce said part; and

c) removing said mold material by use of a second removing means, said second removing means not removing said part material.

2. The method of claim 1 wherein said part material comprises a gelcasting material.

3. The method of claim 2 wherein said gelcasting material comprises a ceramic gelcasting slurry.

4. The method of claim 2 wherein said gelcasting material comprises a metal gelcasting slurry.

5. The method of claim 1 wherein said part material comprises a polymer.

6. The method of claim 1 wherein step (iii) comprises dissolving said support material.

7. The method of claim 1 wherein step (iii) comprises melting said support material.

8. The method of claim 1 further comprising a step of removing said part by liquefying said mold after step (b).

9. The method of claim 8 wherein said step of removing said part comprises dissolving said mold.

10. The method of claim 8 wherein said step of removing said part comprises melting said mold.

11. The method of claim 1 wherein step (ii) comprises shaping said support segment to define an undercut surface of said mold.

12. The method of claim 11 further comprising a step of shaping said mold segment to define a non-undercut surface of said mold.

13. The method of claim 1 wherein step (ii) comprises shaping said mold segment to define a non-undercut surface of said mold.

14. The method of claim 1 wherein the support material is ultraviolet-curable, water-soluble polymer.

69. The method of claim 1, 15, 28, 35 or 51, wherein said predetermined deposition fashion includes:

a) deposition of a first of said mold layers with a first thickness that is predetermined equal to at least one other of said mold layer, and wherein said first thickness being constant within said layer;

b) deposition of a second of said deposition layers with a second thickness varying relative to at least one other of said mold layer;

c) deposition of a third of said mold layers having a planar bottom surface and a top surface shaped in correspondence with a feature contour of said mold shape;

d) deposition of a fourth of said mold layers having a planar top surface and a bottom surface shaped in correspondence with a feature contour of said mold shape; and

e) deposition of a fifth of said mold layers having a top surface and a bottom surface shaped in correspondence with feature contours of said mold shape.

70. The method of claim 1 or 15, wherein said first removing means is a thermal removing means providing melting.

71. The method of claim 1 or 15, wherein said first removing means is a non-thermal dissolving means providing dissolving.

72. The method of claim 71, wherein said non-thermal dissolving means is water based.

73. The method of claim 71, wherein said non-thermal dissolving means is an organic solvent.

74. The method of claim 1 or 15, wherein said second removing means is a thermal removing means providing melting.

75. The method of claim 1 or 15, wherein said second removing means is a non-thermal dissolving means providing dissolving.

76. The method of claim 75, wherein said non-thermal dissolving means is water based.

77. The method of claim 75, wherein said non-thermal dissolving means is an organic solvent.

82. The method of claim 1, 15, 28, 35, or 51, wherein said shaping is selected from the group consisting of three to five axis milling, turning and electrical discharge machining.

15. A method of making a complex three-dimensional molded part, comprising the steps of:

a) depositing a mold segment formed of mold material in a predetermined deposition fashion, wherein said mold material being removing resistant against a first removing means and being removable by a second removing means;

b) primary shaping said mold segment within a deposition height of said mold segment, wherein said primary shaping includes three dimensional material removal in correspondence with a predetermined configuration of said mold surface, said predetermined configuration being independent of said predetermined deposition fashion,;

c) depositing a support segment formed of support material in said predetermined deposition fashion, wherein said support material being removable by said first removing means;

d) secondary shaping said support segment within a deposition height of said support segment, wherein said secondary shaping includes three dimensional material removal in correspondence with at least one of said predetermined configuration and a predetermined support for at least one of a consecutively deposited mold segment and a consecutively deposited support segment;

e) sequentially repeating steps (a), (b), (c), and (d) to generate a plurality of mold layers forming said mold, wherein said predetermined deposition fashion, said primary shaping and said secondary shaping provide final layers selected from the group consisting of;

A) planar layers;

B) non planar layers;

C) wedge shaped layers;

D) layers having an uneven thickness;

E) layers having an undulating thickness;

F) layers having a curved shape; and

G) layers having different thicknesses;

f) after forming said mold, removing said support material from said mold by removing said support material with said first removing means;

g) after step (f), casting part material into said mold;

h) after step (g), solidifying said part material to form said part; and

i) after step (h), removing said part by removing said mold with said second removing means.

16. The method of claim 15 wherein said part material comprises a gelcasting material.

17. The method of claim 16 wherein said gelcasting material comprises a ceramic gelcasting slurry.

18. The method of claim 16 wherein said gelcasting material comprises a metal gelcasting slurry.

19. The method of claim 15 wherein said part material comprises a polymer.

20. The method of claim 15 wherein step (f) comprises dissolving said support material.

21. The method of claim 15 wherein step (f) comprises melting said support material.

22. The method of claim 15 wherein step (i) comprises dissolving said mold.

23. The method of claim 15 wherein step (i) comprises melting said mold.

24. The method of claim 15 wherein step (d) comprises shaping said support segment to define an undercut surface of said mold.

25. The method of claim 24 wherein step (b) comprises the step of shaping said mold segment to define a non-undercut surface of said mold.

26. The method of claim 15 wherein step (b) comprises shaping said mold segment to define a non-undercut surface of said mold.

27. The method of claim 15 wherein the support material is ultraviolet-curable, water-soluble polymer.

28. A method of rapid-prototyping a mold for a complex three-dimensional part, comprising the steps of:

a) sequentially depositing in a predetermined deposition fashion a plurality of mold layers each comprising mold material, at least one of said mold layers comprising a mold segment formed of said mold material and a support segment formed of support material, wherein said mold material being removing resistant against a removing means and wherein said support material being removable by said removing means;

b) shaping a mold surface within a previously deposited mold layer of said plurality of mold layers by shaping at least one of said support segment and said mold segment prior to deposition of a subsequent mold layer above said support segment and said mold segment, to define a surface of said mold, said shaping including three dimensional material removal in correspondence with a predetermined configuration of said mold surface, said predetermined configuration being independent of said predetermined deposition fashion, and wherein said predetermined deposition fashion and said shaping provide final layers selected from the group consisting of;

A) planar layers;

B) non planar layers;

C) wedge shaped layers;

D) layers having an uneven thickness;

E) layers having an undulating thickness;

F) layers having a curved shape; and

G) layers having different thicknesses; and

c) removing said support material from said mold by removing said support material with said removing means.

29. The method of claim 28 wherein step (c) comprises dissolving said support material.

30. The method of claim 28 wherein step (c) comprises melting said support material.

31. The method of claim 28 wherein step (b) comprises shaping said support segment to define an undercut surface of said mold.

32. The method of claim 31 further comprising a step of shaping said mold segment to define a non-undercut surface of said mold.

33. The method of claim 28 wherein step (b) comprises shaping said mold segment to define a non-undercut surface of said mold.

34. The method of claim 28 wherein the support material is ultraviolet-curable, water-soluble polymer.

78. The method of claim 28, 35 or 51, wherein said removing means is a thermal removing means providing melting.

79. The method of claim 28, 35 or 51, wherein said removing means is a non-thermal dissolving means providing dissolving.

80. The method of claim 79, wherein said non-thermal dissolving means is water based.

81. The method of claim 79, wherein said non-thermal dissolving means is an organic solvent.

35. A rapid-prototyping method comprising the steps of:

a) generating a mold by

(i) sequentially depositing in a predetermined deposition fashion a plurality of mold layers each comprising mold material, at least one of said mold layers comprising a mold segment formed of said mold material and a support segment formed of support material, such that said support material forms a plurality of distinct support sections enclosed by said mold material, said plurality of support sections defining a corresponding plurality of distinct cavities in said mold, wherein said mold material being removing resistant against a removing means;

(ii) shaping a mold surface within a previously deposited mold layer of said plurality of mold layers by shaping at least one of said support segment and said mold segment prior to deposition of a subsequent mold layer above said support segment and said mold segment, to define said mold surface, said shaping including three dimensional material removal in correspondence with a predetermined configuration of said mold surface, said predetermined configuration being independent of said predetermined deposition fashion, and wherein said predetermined deposition fashion and said shaping provide final layers selected from the group consisting of;

A) planar layers;

B) non planar layers;

C) wedge shaped layers;

D) layers having an uneven thickness;

E) layers having an undulating thickness;

F) layers having a curved shape; and

G) layers having different thicknesses;

(iii) removing said support material from said mold by removing said support material with said removing means, thereby providing said plurality of cavities in said mold;

b) casting part material into said plurality of cavities to form a part comprising a plurality of part sections corresponding to said plurality of cavities; and

c) solidifying said part material.

36. The method of claim 35 wherein said plurality of support sections are interlocked, whereby said plurality of part sections are interlocked.

37. The method of claim 35 wherein said part material comprises a gelcasting material.

38. The method of claim 37 wherein said gelcasting material comprises a ceramic gelcasting slurry.

39. The method of claim 37 wherein said gelcasting material comprises a metal gelcasting slurry.

40. The method of claim 35 wherein said part material comprises a polymer.

41. The method of claim 35 wherein step (iii) comprises dissolving said support material.

42. The method of claim 35 wherein step (iii) comprises melting said support material.

43. The method of claim 35 further comprising a step of removing said part by liquefying said mold after step (c).

44. The method of claim 43 wherein said step of removing said part comprises dissolving said mold.

45. The method of claim 43 wherein said step of removing said part comprises melting said mold.

46. The method of claim 35 wherein step (ii) comprises shaping said support segment to define an undercut surface of said mold.

47. The method of claim 46 further comprising a step of shaping said mold segment to define a non-undercut surface of said mold.

48. The method of claim 35 wherein step (ii) comprises shaping said mold segment to define a non-undercut surface of said mold.

49. The method of claim 35 wherein said part material comprises different materials in different cavities.

50. The method of claim 35 wherein the support material is ultraviolet-curable, water-soluble polymer.

51. A rapid-prototyping method comprising the steps of:

a) generating a mold by

(i) sequentially depositing in a predetermined deposition fashion a plurality of mold layers each comprising mold material, at least one of said mold layers comprising a mold segment formed of said mold material and a support segment formed of support material, such that said support material forms a first support section and a second support section, said first support section being distinct from said second support section, said support sections being enclosed by said mold material, wherein said mold material being removing resistant against a first removing means and being removable by a second removing means, and wherein said support material being removable by said first removing means;

(ii) shaping a mold surface within a previously deposited mold layer of said plurality of mold layers by shaping at least one of said support segment and said mold segment prior to deposition of a subsequent mold layer above said support segment and said mold segment, to define a surface of said mold, said shaping including three dimensional material removal in correspondence with a predetermined configuration of said mold surface, said predetermined configuration being independent of said predetermined deposition fashion, and wherein said predetermined deposition fashion and said shaping provide final layers selected from the group consisting of;

G) planar layers;

H) non planar layers;

I) wedge shaped layers;

J) layers having an uneven thickness;

K) layers having an undulating thickness;

L) layers having a curved shape; and

M) layers having different thicknesses;

b) removing with said first removing means said first support section to open said first mold cavity;

c) casting said first part-forming material into said first mold cavity to form a first part section;

d) solidifying said first part-forming material in said first mold cavity;

e) secondarily shaping an access aperture connecting said first part section and said second mold cavity defined by said second support section enclosed by said mold;

f) removing with said first removing means said second support section through said access aperture to open said second mold cavity;

g) casting a second part-forming material into said second mold cavity and said access aperture to form a second part section connected to said first part section; and

h) solidifying said second part-forming material.

52. The method of claim 51 wherein said first part-forming material and said second part-forming material consist of different materials.

53. The method of claim 51 wherein said first part-forming material comprises a gelcasting material.

54. The method of claim 53 wherein said gelcasting material comprises a ceramic gelcasting slurry.

55. The method of claim 53 wherein said gelcasting material comprises a metal gelcasting slurry.

56. The method of claim 51 wherein said first part-forming material comprises a polymer.

57. The method of claim 51 wherein said second part-forming material comprises a gelcasting material.

58. The method of claim 57 wherein said gelcasting material comprises a ceramic gelcasting slurry.

59. The method of claim 57 wherein said gelcasting material comprises a metal gelcasting slurry.

60. The method of claim 51 wherein said second part-forming material comprises a polymer.

61. The method of claim 51 wherein step (b) comprises dissolving said first support section.

62. The method of claim 51 wherein step (b) comprises melting said first support section.

63. The method of claim 51 wherein step (e) comprises dissolving said second support section.

64. The method of claim 51 wherein step (e) comprises melting said second support section.

65. The method of claim 51 further comprising a step of liquefying said mold after step (g).

66. The method of claim 65 wherein said step of liquefying comprises dissolving said mold.

67. The method of claim 65 wherein said step of liquefying comprises melting said mold.

68. The method of claim 51 wherein the support material is ultraviolet-curable, water-soluble polymer.

83. The method of claim 51, wherein said first part-forming material and said second part-forming material are identical.