Bubble-free cross-sections for use in solid imaging

• US 20060249884A1
• Filed: 03/15/2006
• Published: 11/09/2006
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: McNamara, Dennis F. Jr., Hull, Charles W., Partanen, Jouni P., Soliz, Raymond M., Sperry, Charles R.
• Granted Patent: US 7,906,061 B2
• Time in Patent Office: Days
• US Class Current: 264/401
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• 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 50/00 Data acquisition or data processing for additive manufacturing

Abstract

A solid imaging apparatus and method employing build material transfer means effective to transfer solidifiable liquid build material from a first side of a radiation transparent build material carrier to a receiving substrate without entrapping air bubbles in layers of transferred solidifiable liquid build material and to cleanly separate the solidified build material from the radiation transparent build material carrier as each layer is formed during the layerwise building of a three-dimensional object. An expandable membrane forming an arcuate dome and a reciprocatible flexible film are employed to effect transfer of the solidifiable liquid build material.

Claims

1. A method for forming a three-dimensional object layer-by-layer comprising the steps of:

a. receiving three-dimensional CAD data of an object to be built;

b. processing the three-dimensional CAD data to receive slice data representative of cross-sectional layers of the object;

c. converting the slice data into bit-map data;

d. delivering a solidifiable liquid build material to an imaging area via a radiation transparent build material carrier having a first side and an opposing second side;

e. transferring the solidifiable liquid build material from the radiation transparent build material carrier to a receiving substrate sequentially in each layer in a manner that avoids entrapment of air bubbles in the transferred solidifiable liquid build material; and

f. projecting an image representative of cross-sectional image data from a radiation source through the radiation transparent build material carrier to selectively illuminate pixels in an image plane in a first exposure to selectively solidify the liquid build material.

2. The method according to claim 1 further comprising repeating steps d-f multiple times until a complete three-dimensional object is formed.

3. The method according to claim 1 further comprising using an endless belt as the radiation transparent build material carrier.

4. The method according to claim 1 further comprising using a flexible film as the radiation transparent build material carrier.

5. The method according to claim 3 further comprising using an expandable membrane to contact the radiation transparent build material carrier, the membrane expanding to form an arcuate dome with a high point and lower points on the dome.

6. The method according to claim 5 further comprising the expandable membrane contacting the radiation transparent build material carrier initially at the high point and then sequentially at the lower points to cause the solidifiable liquid build material to transfer from the first side to the receiving substrate.

7. The method according to claim 5 further comprising the expandable membrane contacting the radiation transparent build material carrier initially at the lowest points and then sequentially at higher points to cause the selectively solidified liquid build material to separate from the radiation transparent build material carrier and remain connected to the receiving substrate as the three-dimensional object is built layer-by-layer.

8. The method according to claim 6 further comprising the receiving substrate being on a support platform moveable between a raised position in contact with the solidifiable liquid build material on the first side and a lowered position, the support platform supporting the three-dimensional object as it is built layer-by-layer.

9. The method according to claim 7 further comprising the receiving substrate being on a support platform moveable between a raised position in contact with the solidifiable liquid build material on the first side and a lowered position, the support platform supporting the three-dimensional object as it is built layer-by-layer.

10. The method according to claim 8 further comprising the expandable membrane being retained in a frame connectable to a source of gas selectively flowable into and out of the frame between the frame and the membrane effective to expand the frame upon inflow and to permit the membrane to flatten upon the support platform contacting the first side of the radiation transparent build material carrier and the solidifiable liquid build material during delivery of the solidifiable liquid build material to the receiving substrate.

11. The method according to claim 10 further comprising the gas flowing through passageways in the frame so air flows into the frame between the frame and the expandable membrane.

12. The method according to claim 8 further comprising the transparent build material carrier peeling away from solidified build material in a formed layer of the three-dimensional object upon expansion of the expandable membrane and lowering of the support platform.

13. The method according to claim 4 further comprising using a reciprocatible carriage to which is reciprocatingly mounted the radiation transparent build material carrier.

14. The method according to claim 13 further comprising the radiation transparent build material carrier contacting the receiving substrate sequentially to transfer the solidifable liquid build material from the first side to the receiving substrate.

15. The method according to claim 14 further comprising the transparent build material carrier being reciprocatibly mounted about a plurality of guides in a geometric pattern, the transparent build material carrier moving reciprocatibly across an image plane.

16. The method according to claim 15 further comprising having at least one guide being a driver guide to reciprocatibly move the transparent build material carrier across the image plane.

17. The method according to claim 16 further comprising the plurality of guides being three rollers in a triangular pattern.

18. The method according to claim 17 further comprising having the transparent build material carrier communicating with a source of solidifiable liquid build material after each pass across the image plane to receive additional solidifiable liquid build material.

19. The method according to claim 14 further comprising transferring the solidifiable liquid build material to the receiving substrate with no relative motion between the radiation transparent build material carrier and the receiving substrate.

20. The method according to claim 19 further comprising the transparent build material carrier peeling away from solidified build material in a formed layer of the three-dimensional object with no relative motion therebetween.

21. The method according to claim 1 further comprising a radiation source being selected from the group consisting of a UV radiation source and a visible light source.

22. An apparatus for forming a three-dimensional object layer-by-layer by solid imaging comprising in combination:

a. a frame;

b. a radiation transparent build material carrier moveably mounted to the frame, the radiation transparent build material carrier having a first side and an opposing second side;

c. a radiation source mounted to the frame for projecting through the transparent build material carrier a full image one cross-section at a time of a three-dimensional object to be built;

d. a source of solidifiable liquid build material in fluid transfer communication with the radiation transparent build material carrier effective to apply the solidifiable liquid build material to the first side of the radiation transparent build material carrier;

e. a support platform moveably mounted to the frame to support the three-dimensional object as it is built in cross-sections layer-by-layer;

f. control means mounted to the frame effective to control movement of the radiation transparent build material carrier and the support platform and to control illumination of selected pixels by the radiation source in an image exposure of a cross-section of the three-dimensional object on the solidifiable liquid build material to thereby form a solidified cross-section;

g. processing means in data flow communication with the control means to receive CAD data and convert the CAD data into sliced data representative of cross-sections of the three-dimensional object; and

h. build material transfer means connected to the frame effective to transfer solidifiable liquid build material from the first side of the radiation transparent build material carrier to a receiving substrate without entrapping air bubbles in layers of transferred solidifiable liquid build material.

23. The apparatus according to claim 22 further comprising the radiation source being selected one from the group consisting of a UV radiation source and a visible light source.

24. The apparatus according to claim 22 further comprising the radiation source being a digital light projector.

25. The apparatus according to claim 22 further comprising the radiation transparent build material carrier being an endless belt.

26. The apparatus according to claim 22 further comprising the radiation transparent build material carrier further being a flexible film.

27. The apparatus according to claim 25 further comprising the build material transfer means including an expandable membrane, the membrane forming an arcuate dome with a high point and lower points on a domed surface upon expansion that is contactable with the opposing second side of the radiation transparent build material carrier initially at the high point and then sequentially at lower points about the domed surface in a manner effective to transfer the solidifiable liquid build material from the first side to the receiving substrate.

28. The apparatus according to claim 25 further comprising the build material transfer means including an expandable membrane, the membrane forming an arcuate dome with a high point and lower points on a domed surface upon expansion that is separable from the opposing second side of the radiation transparent build material carrier initially at lower points and then sequentially at higher points about the domed surface in a manner effective to cause solidified liquid build material in the exposed cross-section of the three-dimensional object to separate from the radiation transparent build material carrier and remain connected to the receiving substrate.

29. The apparatus according to claim 27 further comprising the expandable membrane being retained in a frame, the frame being connected to a source of gas selectively flowable into and out of the frame between the frame and the expandable membrane effective to expand the membrane upon inflow and to permit the membrane to flatten upon the support platform contacting the first side of the radiation transparent build material carrier during delivery of the solidifiable build material to the receiving substrate.

30. The apparatus according to claim 28 further comprising the expandable membrane being retained in a frame, the frame being connected to a source of gas selectively flowable into and out of the frame between the frame and the expandable membrane effective to expand the membrane upon inflow and to permit the membrane to flatten upon outflow.

31. The apparatus according to claim 29 further comprising the frame having passageways for gas to flow into the frame between the frame and the expandable membrane.

32. The apparatus according to claim 30 further comprising the frame having passageways for gas to flow into and out of the frame between the frame and the expandable membrane.

33. The apparatus according to claim 26 further comprising the build material transfer means including a reciprocatable carriage to which is reciprocatibly mounted the radiation transparent build material carrier.

34. The apparatus according to claim 33 further comprising the radiation transparent build material carrier sequentially being contactable with the receiving substrate to transfer the solidifiable liquid build material from the first side to the receiving substrate.

35. The apparatus according to claim 34 further comprising the radiation transparent build material carrier being reciprocatibly mounted about a plurality of guides in a geometric pattern, the radiation transparent build material carrier moving reciprocatibly across an image plane.

36. The apparatus according to claim 35 further comprising at least one guide being a driver guide to reciprocatibly move the radiation transparent build material carrier across the image plane.

37. The apparatus according to claim 36 further comprising the radiation transparent build material carrier communicating with the source of solidifiable liquid build material after each pass across the image plane to receive additional solidifiable liquid build material.

38. The apparatus according to claim 36 further comprising the plurality of guides being three rollers in a triangular pattern.

39. The apparatus according to claim 34 further comprising the radiation transparent build material carrier means transferring the solidifiable liquid build material to the receiving substrate with no relative motion between the radiation transparent build material carrier and the receiving substrate.

40. The apparatus according to claim 39 further comprising the radiation transparent build material carrier peeling away from the solidified build material in the solidified cross-section of the three-dimensional object with no relative motion therebetween.