Selective deposition modeling with curable phase change materials

• US 20030083771A1
• Filed: 10/03/2001
• Published: 05/01/2003
• Est. Priority Date: 10/03/2001
• Status: Active Grant

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Schmidt, Kris Alan
• Granted Patent: US 6,841,116 B2
• Time in Patent Office: Days
• US Class Current: 700/119
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B29C 64/188 involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00
• 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 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor

Abstract

A selective deposition modeling method and apparatus for dispensing a curable phase change material. The dispensing temperature of the material is set at or less than a thermally stable temperature value for the material in which the reactive component of the material remains substantially uncured when held at the temperature for a desired time period. The dispensed material is provided with an environment that enables the material to solidify to form layers of the object. The solidified material is normalized to a desired layer thickness and is then cured by exposure to actinic radiation. In a preferred embodiment a UV curable phase change material is dispensed at about 80° C. and has a viscosity of about 13 to about 14 centipoise at this temperature. The cured material provides substantially increased physical properties over thermoplastic phase change materials previously used in selective deposition modeling.

Claims

1. A method of forming a three-dimensional object in a layerwise manner, the method comprising the steps of:

generating computer data corresponding to layers of the object

providing a thermally stable dispensing environment for a radiation curable phase change material having at least one reactive component, the dispensing environment having a dispensing temperature wherein the material can be maintained at the dispensing temperature in a flowable state for a desired time period while the reactive component of the material remains substantially uncured;

dispensing the curable phase change material in a flowable state at the dispensing temperature according to the computer data to form layers of the object;

lowering the temperature of the dispensed material causing the material to solidify to a non-flowable state;

supporting a first dispensed layer of the three-dimensional object and providing a working surface for forming subsequent layers on top of a previous layer; and

curing the solidified material by exposure to radiation.

2. The method of claim 1 wherein the desired time period in which the curable phase change material can be maintained at the dispensing temperature while the reactive component of the material remains substantially uncured is at least 1 hour.

3. The method of claim 2 wherein the curable phase change material can be maintained at the dispensing temperature for at least 1 hour while the viscosity of the material does not increase by more than about 20%.

4. The method of claim 1 wherein the desired time period in which the curable phase change material can be maintained at the dispensing temperature while the reactive component of the material remains substantially uncured is between about 2 to about 8 weeks.

5. The method of claim 4 wherein the curable phase change material can be maintained at the dispensing temperature for about 2 to about 8 weeks while the viscosity of the material does not increase by more than about 20%.

6. The method of claim 1 wherein the dispensing temperature is no greater than about 90°

C. and the phase change material has a viscosity of no greater than about 18 centipoise at the dispensing temperature.

7. The method of claim 1 wherein the dispensing temperature is about 80°

C. and the phase change material has a viscosity of about 13 centipoise at the dispensing temperature.

8. The method of claim 1 wherein the step of dispensing the material comprises using at least one print head having a plurality of dispensing orifices for dispensing the phase change material at a viscosity of between about 10.5 to about 18 centipoise at the dispensing temperature.

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

passing a planarizer over the solidified material to establish a layer thickness for each layer prior to curing the layer.

10. The method of claim 1 wherein the step of curing the material is performed after at least two layers of the object have been formed.

11. The method of claim 1 wherein the step of curing the solidified dispensed material is performed for each layer after each layer is dispensed and prior to dispensing a next layer of material.

12. The method of claim 1 wherein the step of curing the material is performed by providing flood exposure to ultraviolet radiation.

13. The method of claim 1 wherein the step of lowering the temperature of the dispensed material to solidify the material comprises lowering the temperature to between about 40°

C. to about 80°

C.

14. The method of claim 1 wherein the step of lowering the temperature of the dispensed material to solidify the material comprises lowering the temperature to between about 40°

C. to about 55°

C.

15. The method of claim 1 wherein the method is performed by a selective deposition modeling system.

16. A method for forming a three-dimensional object in a layerwise manner, the method comprising the steps of:

generating computer data corresponding to layers of the object;

providing a radiation curable phase change material having at least one reactive component, the material having a thermally stable temperature, the thermally stable temperature being the greatest temperature at which the material can be maintained for a desired time period in which the reactive component in the material remains substantially uncured;

elevating the temperature of the material to a dispensing temperature wherein the material transitions to a flowable state, the dispensing temperature being equal to or less than the thermally stable temperature;

dispensing the material in the flowable state at the dispensing temperature according to the computer data to form a layer of the object;

lowering the temperature of the dispensed material causing the material to solidify to a non-flowable state; and

curing the dispensed material by exposure to radiation.

17. The method of claim 16 wherein the desired time period is at least 1 hour.

18. The method of claim 17 wherein during the desired time period the viscosity of the material does not increase by more than about 20%.

19. The method of claim 16 wherein the desired time period is between about 2 to about 8 weeks.

20. The method of claim 19 wherein during the desired time period the viscosity of the material does not increase by more than about 20%.

21. The method of claim 16 wherein the dispensing temperature is not greater than 90°

C. and the phase change material has a viscosity of no greater than about 18 centipoise at the dispensing temperature.

22. The method of claim 16 wherein the dispensing temperature is about 80°

C. and the curable phase change material has a viscosity of about 13 centipoise at the dispensing temperature.

23. The method of claim 16 wherein the thermally stable temperature is no greater than about 90°

C.

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

passing a planarizer over the solidified material to establish a layer thickness for each layer prior to curing the layer.

25. The method of claim 16 wherein the step of curing the material is performed after at least two layers of the object have been formed.

26. The method of claim 16 wherein the step of curing the solidified dispensed material is performed for each layer after each layer is dispensed and solidified.

27. The method of claim 16 wherein the step of curing the material is performed by providing flood exposure to ultraviolet radiation.

28. The method of claim 16 wherein the step of lowering the temperature of the dispensed material to solidify the material comprises lowering the temperature to between about 40°

C. to about 80°

C.

29. The method of claim 16 wherein the step of lowering the temperature of the dispensed material to solidify the material comprises lowering the temperature to between about 40°

C. to about 55°

C.

30. The method of claim 16 wherein the method is performed by a selective deposition modeling system.

31. A method for forming a three-dimensional object in a layerwise manner by solid freeform fabrication, the method comprising the steps of:

generating computer data corresponding to layers of the object;

providing a radiation curable phase change material having at least one reactive component, the curable phase change material having a thermally stable temperature and a melting point, the melting point being no greater than about 80°

C., the thermally stable temperature being the greatest temperature at which the material can be maintained for a desired time period in which the reactive component in the material remains substantially uncured;

elevating the temperature of the material to a dispensing temperature, the dispensing temperature being at least equal to or greater than the melting point of the material and at least equal to or less than the thermally stable temperature value of the material;

dispensing the material in a flowable state at the dispensing temperature according to the computer data to form layers of the object;

lowering the temperature of the dispensed material causing the material to solidify to a non-flowable state;

exposing the solidified dispensed material to radiation to cure the reactive component in the material.

32. The method of claim 31 wherein the desired time period is at least 1 hour.

33. The method of claim 32 wherein during the desired time period the viscosity of the material does not increase by more than about 20%.

34. The method of claim 31 wherein the desired time period is between about 2 to about 8 weeks.

35. The method of claim 34 wherein during the desired time period the viscosity of the material does not increase by more than about 20%.

36. The method of claim 31 wherein the dispensing temperature is no greater than about 90°

C. and the phase change material has a viscosity of no greater than about 18 centipoise at the dispensing temperature.

37. The method of claim 31 wherein the dispensing temperature is about 80°

C. and the curable phase change material has a viscosity of about 13 centipoise at the dispensing temperature.

38. The method of claim 31 wherein the thermally stable temperature is no greater than about 90°

C.

39. The method of claim 31 further comprising the step of:

passing a planarizer over the solidified material to establish a layer thickness for each layer prior to curing the layer.

40. The method of claim 31 wherein the step of curing the material is performed after all the layers of the object have been formed.

41. The method of claim 31 wherein the step of curing the solidified dispensed material is performed for each layer after each layer is dispensed and solidified.

42. The method of claim 31 wherein the step of curing the material is performed by providing flood exposure to ultraviolet radiation.

43. The method of claim 31 wherein the step of lowering the temperature of the dispensed material to solidify the material comprises lowering the temperature to between about 40°

C. to about 80°

C.

44. The method of claim 31 wherein the step of lowering the temperature of the dispensed material to solidify the material comprises lowering the temperature to between about 40°

C. to about 55°

C.

45. The method of claim 31 wherein the method is performed by a selective deposition modeling system.

46. A method of forming a three-dimensional object in a layerwise manner by solid freeform fabrication, the method comprising the steps of:

generating computer data corresponding to layers of the object;

providing a thermally stable dispensing environment for a radiation curable phase change material having at least one reactive component and a melting point;

the thermally stable dispensing environment having a dispensing temperature greater than the melting point and being no greater than about 90°

C.;

dispensing the curable phase change material in a flowable state at the dispensing temperature according to the computer data, the phase change material having a viscosity no greater than about 18 centipoise at the dispensing temperature;

lowering the temperature of the dispensed material below a freezing point to cause the material to solidify to a non-flowable state to form layers of the object;

supporting a first dispensed layer of the three-dimensional object and providing a working surface for forming subsequent layers on top of a previous layer; and

curing the material by exposure to radiation.

47. The method of claim 46 wherein the dispensing temperature is about 80°

C. and the phase change material has a viscosity of about 13 centipoise at the dispensing temperature.

48. The method of claim 47 wherein the curable phase change material has a melting point between about 50°

C. to about 80°

C. and a freezing point between about 40°

C. to about 80°

C. and wherein the step of lowering the temperature of the material to solidify the material to the non-flowable state lowers the temperature below the freezing point of the material.

49. The method of claim 48 wherein the melting point is between about 50°

C. to about 60°

C. and the freezing point is between about 40°

C. to about 60°

C.

50. The method of claim 47 further comprising the step of:

generating support data corresponding to supports needed for the object;

dispensing a non-curable phase change material in a flowable state according to the support data to form a support structure for the three dimensional object;

lowering the temperature of the dispensed non-curable material causing the material to solidify to a non-flowable state to form portions of the support structure for the object.

51. The method of claim 50 further comprising the step of:

passing a planarizer over the solidified material to establish a layer thickness for each layer prior to curing the layer.

52. The method of claim 51 wherein the steps are repeated until the three-dimensional object is formed and cured, the method comprising the step of:

removing the support structure from the object.

53. The method of claim 52 wherein the support structure is removed by melting away the non-curable material.

54. The method of claim 53 wherein the support structure is removed by application of a solvent that dissolves the non-curable material.

55. A selective deposition modeling apparatus for forming a three-dimensional object on a layer-by-layer basis by dispensing a curable phase change material having at least one reactive component, comprising:

a computer system for processing data corresponding to layers of the object;

a means for dispensing the curable phase change material in a flowable state at a dispensing temperature according to the data processed by the computer system to form a layer, the dispensing temperature not exceeding a thermally stable temperature of the material, the thermally stable temperature being the greatest temperature that the material can be maintained at for a desired time period in which the reactive component in the material remains substantially uncured;

a means for supporting the dispensed material as the material solidifies to a non-flowable state to form the layers of the object;

a means for normalizing the surface of the layers to establish a uniform layer thickness;

a means for exposing the solidified material to radiation to cure the reactive component of the material.

56. The apparatus of claim 55 wherein:

the means for dispensing the curable phase change material comprises at least one print head operated at a dispensing temperature no greater than about 90°

C.

57. The apparatus of claim 56 wherein:

the computer system processes data corresponding to support regions for the object; and

means for dispensing a non-curable phase change material according to the data processed by the computer system to form supports for the object.

58. The apparatus of claim 57 wherein the print head dispenses both the curable phase change material and the non-curable phase change material.

59. The apparatus of claim 58 comprising a plurality of print heads wherein some of the print heads are dedicated to dispensing the curable phase change material and the others are dedicated to dispensing the non-curable phase change material.

60. The apparatus of claim 55 further comprising:

a means for cooling the dispensed layers to remove heat from the object to allow the dispensed material to solidify.

61. The apparatus of claim 55 wherein the means for normalizing the surface of the layers comprises a planarizer that is passed over the solidified material to establish a layer thickness for each layer prior to curing the layer.

62. The apparatus of claim 61 wherein the planarizer accumulates waste material when normalizing the layers, and the apparatus further comprises:

a means for removing the waste material from the planarizer.

63. A method of forming a three-dimensional object in a layerwise manner by dispensing an actinic radiation curable build material from a dispenser, the improvement comprising:

dispensing the build material from a dispenser at a temperature of from about 60°

C. to about 90°

C.; and

curing the dispensed material by exposure to actinic radiation.

64. The method of claim 63 wherein the build material is dispensed from an ink jet print head.

65. The method of claim 63 wherein the build material is dispensed at a temperature of from about 60°

C. to about 80°

C.

66. The method of claim 63 wherein the build material is dispensed at a viscosity of from about 10.5 to about 18 centipoise.

67. The method of claim 63 wherein the build material is dispensed at a viscosity of from about 13 to about 14 centipoise.