APPARATUS AND METHOD FOR FORMING THREE-DIMENSIONAL OBJECTS USING A TILTING SOLIDIFICATION SUBSTRATE

• US 20150231831A1
• Filed: 02/19/2015
• Published: 08/20/2015
• Est. Priority Date: 02/20/2014
• Status: Active Grant

• Current Assignee: Gulf Filtration Systems Inc. (Desktop Metal, Inc.)
• Original Assignee: Gulf Filtration Systems Inc. (Desktop Metal, Inc.)
• Inventors: El-Siblani, Ali
• Granted Patent: US 10,144,205 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 64/241 for rotary motion
• CPC Class Codes: B29C 64/255 Enclosures for the building material, e.g. powder containers
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B29K 2105/0002 monomers or prepolymers
• CPC Class Codes: B29K 2827/12 containing fluorine
• CPC Class Codes: B29K 2995/0026 Transparent
• 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

An apparatus and method for making a three-dimensional object from a solidifiable material using a linear solidification device is shown and described. The apparatus includes a solidification substrate that is tiltable relative to a film about a tilting axis. Layers of the solidifiable material solidify in contact with a film located between the most recently solidified object layer and a solidification substrate that comprises the solidification substrate assembly. The tilting of the solidification substrate relative to the film allows the substrate to be used to squeeze excess solidifiable material from between the film and the most recently solidified object surface while minimizing or eliminating the formation of bubbles in the solidifiable material which can prolong object build times. In addition, tilting the solidification substrate before separating an adhered object surface from the film breaks any vacuum formed between the substrate and the film which reduces the forces involved in separating the object form the film.

Claims

1. An apparatus for making a three-dimensional object from a solidifiable material, comprising:

a build platform movable along a first axis;

a solidification energy source;

a film assembly;

a solidification substrate assembly comprising a rigid or semi-rigid solidification substrate that is transparent and/or translucent;

an actuator operatively connected to the solidification substrate assembly; and

at least one controller operatively connected to the actuator, wherein the at least one controller comprises a processor and a non-transitory computer readable medium having computer executable instructions stored thereon, and when the computer executable instructions are executed by the processor, the at least one controller generates an actuator activation signal;

wherein the film assembly includes at least one frame, and a film disposed in the at least one frame, the solidification substrate is located between the solidification energy source and the film along the first axis, and the solidification substrate assembly is tiltable relative to the film assembly about a second axis perpendicular to the first axis when the actuator receives the actuator activation signal.

2. The apparatus of claim 1, wherein the solidifiable material has a viscosity at 25°

C. that is at least about 200 cP.

3. The apparatus of claim 1, wherein the solidification energy source is movable along a third axis perpendicular to the first axis and the second axis.

4. The apparatus of claim 1, wherein the film is located between the build platform and the solidification energy source along the first axis.

5. The apparatus of claim 1, further comprising a load frame, wherein the rigid or semi-rigid solidification substrate is disposed in a substrate frame, and the substrate frame is hingedly connected to the load frame.

6. The apparatus of claim 5, further comprising a work table, wherein the load frame is connected to the work table, and the at least one frame of the film assembly is connected to the load frame.

7. The apparatus of claim 5, wherein the substrate frame is hingedly connected to the load frame at a first substrate frame location, the actuator is connected to the substrate frame at a second substrate frame location, and the first substrate frame location and the second substrate frame location are spaced apart along a third axis.

8. The apparatus of claim 1, wherein the actuator has a shaft with a distal end that is operatively connected to the solidification substrate assembly, the actuator shaft is extendable to a first position along the first axis and retractable to a second position along the first axis to tilt the solidification substrate assembly about the second axis.

9. The apparatus of claim 8, wherein the actuator is a pneumatic actuator.

10. The apparatus of claim 1, wherein the second axis is spaced apart from the film assembly in a direction along a third axis.

11. The apparatus of claim 8, wherein the actuator activation signal causes the actuator shaft distal end to extend from the second position to the first position after solidifying a layer of the solidifiable material and prior to solidifying a next layer of the solidifiable material.

12. The apparatus of claim 11, wherein the actuator activation signal causes the actuator shaft distal end to extend from the second position to the first position before the build platform moves away from the solidification substrate assembly along the first axis.

13. The apparatus of claim 8, wherein the actuator activation signal causes the actuator shaft distal end to retract from the first position to the second position after solidifying a layer of the solidifiable material and prior to solidifying a next layer of the solidifiable material.

14. The apparatus of claim 13, wherein the actuator activation signal causes the actuator shaft distal end to retract from the second position to the first position before the build platform moves away from the solidification substrate assembly along the build axis.

15. The apparatus of claim 1, wherein the actuator has a proximal end that is operatively connected to the solidification substrate assembly, and the actuator proximal end is extendable to a first position along the first axis and retractable to a second position along the first axis to tilt the solidification substrate assembly about the second axis.

16. The apparatus of claim 15, wherein the actuator activation signal causes the actuator proximal end to extend from the second position to the first position after solidifying a layer of the solidifiable material and prior to solidifying a next layer of the solidifiable material.

17. The apparatus of claim 16, wherein the actuator activation signal causes the actuator proximal end to extend from the first position to the second position before the build platform moves away from the solidification substrate assembly along the build axis.

18. The apparatus of claim 1, further comprising a tilting parameter database, wherein the tilting parameter database comprises a plurality of solidifiable material identifiers and a plurality of sets of tilting parameters, each solidifiable material identifier is associated with a set of tilting parameters from the plurality of sets of tilting parameters, and each set of tilting parameters comprises at least one tilting parameter.

19. The apparatus of claim 18, wherein the at least one tilting parameter is selected from the group consisting of an actuator tilting distance, a build platform velocity, and an actuator velocity.

20. The apparatus of claim 1, wherein the at least one controller is operatively connected to the source of solidification energy, and when the computer executable instructions are executed by the processor, the at least one controller generates a plurality of solidification energy signals that selectively activate the source of solidification energy to solidify a layer of the solidifiable material in a pattern corresponding to the three-dimensional object, and the at least one controller generates the actuator activation signal after the cessation of a final solidification energy signal for the layer and before the generation of an initial solidification energy signal for a next layer.

21. The apparatus of claim 1, wherein the actuator activation signal causes the actuator to tilt the solidification substrate assembly about the second axis in a direction away from the build platform.

22. The apparatus of claim 21, wherein the actuator activation signal is a first actuator activation signal, and when the computer executable instructions are executed by the processor, the at least one controller generates a second actuator activation signal that causes the actuator to tilt the solidification substrate assembly about the second axis in a direction toward the build platform.

23. The apparatus of any claim 1, wherein the actuator has one selected from a distal shaft end with an end of travel location along the first axis and a proximal housing end with an end of travel along the proximal axis, the apparatus further comprises a switch positioned to generate an end of travel signal when the one selected from the actuator distal shaft end and the actuator proximal housing end reaches the end of travel location, the switch is connected to the at least one controller, and when the computer executable instructions are executed by the processor, the at least one controller generates the actuator activation signal in response to receiving the end of travel signal.

24. The apparatus of claim 1, wherein the actuator activation signal causes the actuator to tilt the solidification substrate assembly about the second axis in a direction toward the build platform.

25. The apparatus of claim 1, further comprising a solidifiable material container having a closed bottom, an open top, and a volume of the solidifiable material, wherein the at least one frame in the film assembly is located at a first distance from the bottom of the solidifiable material container, and the solidifiable material has an exposed surface spaced apart from the bottom of the solidifiable material container by a second distance along the first axis, and the second distance is greater than the first distance.

26. The apparatus of claim 1, further comprising a sensor configured to provide a value indicative of a force or a pressure applied by the solidifiable material to the film.

27. The apparatus of claim 1, further comprising a database, wherein the database comprises a plurality of solidifiable material identifiers and a plurality of leveling wait times, and each solidifiable material identifier in the plurality of solidifiable material identifiers corresponds to a leveling wait time in the plurality of leveling wait times, and the computer readable medium has computer executable instructions stored thereon which, when executed by the processor, select a leveling wait time from among the plurality of leveling wait times based on a user-input solidifiable material identifier.

28. The apparatus of claim 1, further comprising a database, where in the database comprises a plurality of solidifiable material identifiers and a plurality of correlations between leveling wait times and surface areas for a most recently formed object layer, each solidifiable material identifier in the plurality of solidifiable material identifiers corresponds to a correlation from among the plurality of correlations, and the computer readable medium has computer executable instructions stored thereon which, when executed by the processor, calculate a surface area of a most recently formed object layer, select a correlation from among the plurality of correlations based on a user-input solidifiable material identifier, and determine a leveling wait time from the selected correlation based on the calculated surface area of the most recently formed object layer.

29. A method of making a three-dimensional object from a solidifiable material, comprising:

solidifying a first layer of the solidifiable material in a first pattern corresponding to a first portion of the three-dimensional object to form a first solidified exposed object surface in contact with a film disposed between the first layer of the solidifiable material and a rigid or semi-rigid solidification substrate that is transparent and/or translucent, wherein the first layer of the solidifiable material is located between a build platform and the film along a build axis;

first tilting the rigid or semi-rigid solidification substrate relative to the film about a tilting axis in a direction away from the build platform to separate the solidification substrate from the film;

moving the build platform away from the rigid or semi-rigid solidification substrate, thereby separating the film from the first solidified exposed object surface;

providing a second layer of the solidifiable material between the first solidified exposed object surface and the film;

second tilting the solidification substrate relative to the film about the tilting axis in a direction toward the build platform; and

solidifying the second layer of the solidifiable material in a second pattern corresponding to a second portion of the three-dimensional object.

30. The method of claim 29, wherein the step of providing a second layer of the solidifiable material between the first solidified exposed object surface and the film comprises moving the build platform toward the film.

31. The method of claim 29, wherein the step of moving the build platform toward the film is carried out before the step of second tilting the solidification substrate relative to the film about the tiling axis in a direction toward the build platform.

32. The method of claim 29, further comprising providing an actuator operatively connected to the solidification substrate, wherein the actuator has an extended configuration and a retracted configuration, and the step of first tilting the solidification substrate about the tilting axis comprises adjusting the actuator from the retracted configuration to the extended configuration.

33. The method of claim 29, further comprising providing an actuator operatively connected to the solidification substrate, wherein the actuator has an extended configuration and a retracted configuration, and the step of second tilting the solidification substrate about the tilting axis comprises adjusting the actuator from the extended configuration to the retracted configuration.

34. The method of claim 29, further comprising providing an actuator operatively connected to the solidification substrate, wherein the actuator has an extended configuration and a retracted configuration, and the step of first tilting the solidification substrate about the tilting axis comprises adjusting the actuator from the extended configuration to the retracted configuration.

35. The method of claim 29, further comprising providing an actuator operatively connected to the solidification substrate, wherein the actuator has an extended configuration and a retracted configuration, and the step of second tilting the solidification substrate about the tilting axis comprises adjusting the actuator from the retracted configuration to the extended configuration.

36. The method of claim 29, further comprising the step of waiting until the expiration of a leveling wait time after completing the step of second tilting the solidification substrate relative to the film about the tilting axis in a direction toward the build platform and before the step of solidifying the second layer of the solidifiable material in a second pattern corresponding to a second portion of the three-dimensional object.

37. The method of claim 36, further comprising the step of selecting the leveling wait time based on the identity of the solidifiable material.

38. The method of claim 36, further comprising the step of selecting the leveling wait time based on the viscosity of the solidifiable material.

39. The method of claim 36, further comprising the step of calculating the surface area of a most recently formed layer of the three-dimensional object, and selecting the leveling wait time based on a selected correlation between leveling wait times and surface areas of most recently formed object layers.

40. The method of claim 39, further comprising selecting a correlation between leveling wait times and surface areas of most recently formed object layers from among a plurality of correlations between leveling wait times and surface areas of most recently formed object layers based on the identity of the solidifiable material.

41. The method of claim 39, further comprising selecting a correlation between leveling wait times and surface areas of most recently formed object layers from among a plurality of correlations between leveling wait time and surface areas of most recently formed object layers based on the viscosity of the solidifiable material

42. The method of claim 29 further comprising the step of waiting until a pressure or force sensor measurement value reaches a setpoint value after completing the step of second tilting the solidification substrate relative to the film about the tilting axis in a direction toward the build platform and before the step of solidifying the second layer of the solidifiable material in a second pattern corresponding to a second portion of the three-dimensional object.

43. The method of claim 29 further comprising the step of waiting until a pressure or force rate of change value reaches a setpoint value after completing the step of second tilting the solidification substrate relative to the film about the tilting axis in a direction toward the build platform and before the step of solidifying the second layer of the solidifiable material in a second pattern corresponding to a second portion of the three-dimensional object.

44. The method of claim 29, further comprising the step of providing a volume of the solidifiable material having an exposed surface and locating the film beneath the exposed surface.

45. The method of claim 29, wherein the step of first tilting the rigid or semi-rigid solidification substrate relative to the film about a tilting axis in a direction away from the build platform is carried out before the step of moving the build platform away from the rigid or semi-rigid solidification substrate.