Rapid-prototyping method and apparatus

• US 6,838,035 B1
• Filed: 10/09/2000
• Issued: 01/04/2005
• Est. Priority Date: 10/08/1999
• Status: Expired due to Fees

• Current Assignee: Voxeljet Technology GMBH (Voxeljet AG)
• Original Assignee: Voxeljet Technology GMBH (Voxeljet AG)
• Inventors: Ederer, Ingo, Hochsmann, Rainer
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US10/110,006
• Time in Patent Office: 1,548 Days
• Field of Search: 264/308, 425/375, 425/449, 347/1, 347/54
• US Class Current: 264/308
• CPC Class Codes: B22C 23/00 Tools; Devices not mentioned before for moulding
• 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

Abstract

A rapid-prototyping production method for producing a structural body by deposition, in several subsequent deposition steps, of subsequent layers of a building material one onto the other. The building material is selectively deposited in each layer in a liquid state in the form of droplets and being caused to solidify when deposited. After deposition, the layer is lowered into a supporting fluid which has a liquid state and has a density which is at least the same as the density of the building material.

Claims

1. A rapid-prototyping method for producing a structural body by a production process of multiple subsequent depositions of layers of a building material, each subsequent layer of the building material being deposited onto a top surface of a next preceding layer of the building material, the building material having a predetermined first density and being selectively deposited for each layer in a liquid state in a form of droplets into selected subareas of a process area and being caused to start to solidify during deposition, after which a supporting fluid having a liquid state is filled into remaining subareas of said process area which adjoin the selected subareas thereof, wherein the supporting fluid is selected to have a second density which is at least equal to the first density of the building material and is selected to remain in its liquid state throughout the production process, end the remaining subareas of each next preceding layer are filled with the supporting fluid substantially up to the top surface of the building material of said each next preceding layer before the building material of the subsequent layer is deposited thereon without wetting the top surface of the building material with supporting fluid.

2. The method according to claim 1, wherein the remaining subareas of the next preceding layer are filled with the supporting fluid by causing the supporting fluid to flow into the remaining subareas.

3. The method according to claim 2, wherein the supporting fluid is caused to flow into the remaining subareas of the next preceding layer out of a reservoir of supporting fluid having a liquid level by lowering the next preceding layer into the reservoir.

4. The method according to claim 3, wherein the liquid level is maintained constant by means of an overflow of the reservoir.

5. The method according to claim 1, wherein the deposition of the building material for the next preceding layer includes forming of supporting structures for supporting a portion of the subsequent layer.

6. The method according to claim 5, wherein the production process is started by deposition of a lowest layer of the building material onto a platform so as to form spaced apart supporting structures on the platform for supporting a next lowest layer of the building material.

7. The method according to claim 5, wherein said portion of the subsequent layer is a tip of a banging portion intended to hang down from a layer above said subsequent layer.

8. The method according to claim 1, wherein the subsequent layer of the building material is intended to include extending portions of building materiel extending from a portion of the top surface of building material of the next preceding layer over portions of the remaining subareas of the next preceding layer, and the extending portions are formed by starting with deposition of building material from said portion of the top surface and proceeding with deposition of building material along the intended extending portion onto the supporting fluid which was filled into the remaining subareas of the next preceding layer.

9. The method according to claim 1, wherein the subsequent layer of the building material is intended to include extending portions of the building material extending from a portion of the top surface of the building material of the next preceding layer over portions of the remaining subareas of the next preceding layer, and the extending portions of the building material are formed by starting with deposition of the building material onto the supporting fluid which were filled into the remaining subareas of the next preceding layer and proceeding with deposition of the building material along the intended extending portion towards said portion of the top surface.

10. The method of claim 2, wherein the subsequent layer is intended to include surrounding wall portions surrounding a recess portion of the remaining subareas, and the surrounding wall portions are formed, by deposition of the building material, with an opening allowing the supporting fluid to flow into the recess portion.

11. The method according to claim 1, wherein the top surface of the preceding layer is leveled to extend in a horizontal plane before the supporting fluid is filled into the remaining subareas of the preceding layer.

12. The method according to claim 1, wherein the supporting fluid has a viscosity in the range approximately from 150 to 400 mPa'"'"'s.

13. The method according to claim 1, wherein the supporting fluid contains an additive for reducing a surface tension of the supporting fluid.

14. The method according to claim 1, wherein the second density of the supporting fluid is higher than the first density of the building material.

15. The method according to claim 14, wherein the second density of the supporting fluid is approximately 1.01 to 2 times, as high as compared to the first density of the building material.

16. The method according to claim 1, wherein the supporting fluid is a glycerine solution.

17. The method according to claim 16, wherein the glycerine solution comprises an aqueous solution containing glycerine in an amount of approximately 85% by weight and propylenglycol 1.2-propandiol or polysorbat 20 as an additive.

18. The method according claim 1, wherein the building material comprises a fusible material and has a viscosity of not more than 20 mPa'"'"'s when in a molten state at a temperature of not more than 130°

C.

19. The method according to claim 1, wherein the building material comprises at least one liquid resin material which solidifies by reaction with a chemical reaction agent contained in a chemical reaction atmosphere surrounding the building material during deposition.

20. The method according to claim 1, wherein the building material comprises at least one thermosettable resin material and during deposition, the building material is subjected to heat for starting solidification thereof by thermosetting.

22. The method according to claim 14, wherein the second density of the supporting fluid is approximately 1.05 to 1.5 times as high us compared to the first density of the building-material.

23. The method according to claim 18, wherein the building material comprises a wax material or a thermoplastic material.

21. A rapid-prototyping method for producing a structural body by a production process of multiple subsequent depositions of layers of a building material, each subsequent layer of the building material being deposited onto a top surface of a next preceding layer of the building material, the building material having a predetermined first density and being selectively deposited for each layer in a liquid state in a form of droplets into selected subareas of a process area and being caused to start to solidify dining deposition, after which a supporting fluid having a liquid state is filled into remaining subareas of said process area which adjoin the selected subareas thereof, wherein the supporting fluid is selected to have a second density which is at least equal to the first density of the building material and is selected to remain in its liquid state throughout the production process, and the remaining subareas of each next preceding layer are filled with the supporting fluid substantially up to the top surface of the building material of said each next preceding layer before the building material of the subsequent layer is deposited thereon, and the building material comprises at least one liquid main material which is solidified by a reaction with a chemical reaction agent which is contained in the supporting liquid.

24. The method according to claim 21, wherein the remaining subareas of the next preceding layer are filled with the supporting fluid by causing the supporting fluid to flow into the remaining subareas.

25. The method according to claim 24, wherein the supporting fluid is caused to flow into the remaining subareas of the next preceding layer out of a reservoir of supporting fluid having a liquid level by lowering the next preceding layer into the reservoir.

26. The method according to claim 25, wherein the liquid level is maintained constant by means of an overflow of the reservoir.

27. The method according to claim 21, wherein the deposition of the building material for the next preceding layer includes forming of supporting structures for supporting a portion of the subsequent layer.

28. The method according to claim 27, wherein the production process is started by deposition of a lowest layer of the building material onto a platform so as to form spaced apart supporting structures on the platform for supporting a next lowest layer of the building material.

29. The method according to claim 27, wherein said portion of the subsequent layer is a tip of a hanging portion intended to hang down from a layer above said subsequent layer.

30. The method according to claim 21, wherein the subsequent layer of the building material is intended to include extending portions of building material extending from a portion of the top surface of building material of the next preceding layer over portions of the remaining subareas of the next preceding layer, and the extending portions are formed by starting with deposition of building material from said portion of the top surface and preceding with deposition of building material along the intended extending portion of the supporting fluid which was filled into the remaining subareas of the next preceding layer.

31. The method according to claim 21, wherein the subsequent layer of the building material is intended to include extending portions of the building material extending from a portion of the top surface of the building material of the next preceding layer over portions of the remaining subareas of the next preceding layer, and the extending portions of the building material are formed by starting with deposition of the building material onto the supporting fluid which were filled into the remaining subareas of the next preceding layer and proceeding with deposition of the building material along the intended extending portion towards said portion of the top surface.

32. The method of claim 24, wherein the subsequent layer is intended to include surrounding wall portions surrounding a recess pardon of the remaining subareas, and the surrounding wall portions are formed, by deposition of the building material, with an opening allowing the supporting fluid to flow into the recess portion.

33. The method according to claim 21, wherein the top surface of the preceding layer is leveled to extend in a horizontal plane before the supporting fluid is filled into the remaining subareas of the preceding layer.

34. The method according to claim 21, wherein the supporting fluid has a viscosity in the range approximately from 150 to 400 mPa'"'"'s.

35. The method according to claim 21, wherein the supporting fluid contains an additive for reducing a surface tension of the supporting fluid.

36. The method according to claim 21, wherein the second density of the supporting fluid is higher than the first density of the building material.

37. The method according to claim 36, wherein the second density of the supporting fluid is approximately 1.01 to 2 times, as high as compared to the first density of the building material.

38. The method according to claim 36, wherein the second density of the supporting fluid is approximately 1.05 to 1.5 times as high as compared to the first density of the building-material.

39. The method according to claim 21, wherein the supporting fluid is a glycerine solution.

40. The method according to claim 39, wherein the glycerine solution comprises an aqueous solution containing glycerine in an amount of approximately 85% by weight and propylenglycol 1.2-propandiol or polysorbat 20 as an additive.

41. The method according to claim 21, wherein the budding material comprises a fusible material and has a viscosity of not more than 20 mPa'"'"'s when in a molten state at a temperature of not more than 130°

C.

42. The method according to claim 41, wherein the building material comprises a wax material or a thermoplastic material.

43. The method according to claim 21, wherein the building material comprises at least one liquid resin material which solidifies by reaction with a chemical suction agent contained in a chemical reaction atmosphere surrounding the building material during deposition.