CONTINUOUS LIQUID INTERFACE PRODUCTION SYSTEM WITH VISCOSITY PUMP

• US 20170129169A1
• Filed: 11/04/2016
• Published: 05/11/2017
• Est. Priority Date: 11/06/2015
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Batchelder, J. Samuel, Hopkins, Paul E., Chillscyzn, Steven A., Hedlund, Jonathan B.
• Granted Patent: US 10,384,439 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 64/124 using layers of liquid which are selectively solidified
• CPC Class Codes: B29C 64/129 characterised by the energy source therefor, e.g. by global irradiation combined with a mask
• CPC Class Codes: B29C 64/245 Platforms or substrates support structures intended to be sacrificed after manufacture B29C64/40
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• 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 50/02 for controlling or regulating additive manufacturing processes

Abstract

A continuous liquid interface production system includes a source of optical stimulation. The system includes a vessel configured to retain a pool or film of optically sensitive monomer and a substantially optically transparent plate retained by the vessel. The optical stimulation is directed through the plate and into the pool or the film based upon a sliced 3D model of the part. The system includes source of reaction inhibitor wherein the substantially optically transparent plate allows the reaction inhibitor to permeate through the plate and into the pool or the film such that a sufficient amount of reaction inhibitor is within the pool or the film to create a zone proximate the plate that prevents polymerization therein. A build platen is configured to be at least partially immersed into the pool or the film and above the zone as a part is initially being built, wherein a build platen actuator moves the build platen away from the pool or the film in a direction substantially normal to a top surface of the plate. A relative movement actuator provides relative movement between the plate and the part in a direction substantially parallel to the top surface of the plate such that a viscosity pump effect is created that forces monomer between the part being built and the plate.

Claims

1. A continuous liquid interface production system for building a three dimensional part, the system comprising:

a source of optical stimulation, the source configured to form a planar programmably structured image;

a vessel configured to retain a pool or film of an optically sensitive monomer within the vessel;

a substantially optically transparent plate retained by the vessel wherein the substantially optically transparent plate is configured to be positioned below the pool or a film of optically sensitive monomer, wherein the optical stimulation is configured to be directed through the plate and into the pool or film of the optically sensitive monomer;

a source of reaction inhibitor proximate to the substantially optically transparent plate, wherein the substantially optically transparent plate is configured to allow the reaction inhibitor to permeate through the plate and into the pool or the film such that when the system is in use a sufficient concentration of the reaction inhibitor is in the pool or the film proximate the plate to create a zone that prevents polymerization therein;

a build platen configured to be at least partially immersed into the pool or the film and above the zone at least at a beginning of a building process of the three dimensional part;

a build platen actuator configured to move the build platen in a direction substantially normal to a top surface of the plate;

a relative movement actuator configured to provide relative movement between the plate and the part being built in a direction substantially parallel to the top surface of the plate such that a viscosity pump effect is created that forces monomer between the part being built and the top surface of the plate; and

a controller configured to cause the source to project the optical stimulation based upon a sliced 3D model of the part based upon sensed variables comprising at least a height of the build platen.

2. The system of claim 1 and wherein the relative movement actuator is configured to cause angular movement of the build platen relative to the plate.

3. The system of claim 2 and wherein the movement is a rotation in a back and forth motion.

4. The system of claim 2 and wherein the plate comprises a plurality of spiral shaped grooves within the top surface.

5. The system of claim 4 and wherein the plate further comprises an opaque coating below the plurality of grooves wherein the opaque coating is configured to prevent the transmission of light into the pool or the film through the plurality of grooves.

6. The system of claim 4 and wherein the plate comprises a plurality of conduits within the plate wherein the plurality of conduits are located below the plurality of grooves, wherein the plurality of conduits are configured to transport a cooling fluid.

7. The system of claim 6 and wherein each of the plurality of conduits comprises:

a supply portion of the conduit having an inlet proximate a perimeter of the plate; and

a return portion of the conduit having an outlet proximate the perimeter of the plate wherein the supply portion and the return portion are in fluid communication.

8. The system of claim 2 and further comprising:

an angular position sensor configured to sense an angular position of the build platen or the output shaft wherein the angular position sensor is configured to send a signal regarding the sensed angular position to the controller wherein the controller is configured to send a signal to the source of optical stimulation to cause a rotational orientation of the optical stimulation to correlate to that of the sensed rotational position of the build platen or the output shaft.

9. The system of claim 1 and wherein the relative movement actuator comprises:

a driver; and

a drive mechanism engaging the driver and the vessel wherein the driver causes the drive mechanism to move which results in movement of the vessel relative to the part being built.

10. The system of claim 9 and further comprising:

an angular position sensor configured to sense an angular position of the vessel wherein the angular position sensor is configured to send a signal to the controller to monitor the angular speed of the vessel relative to the part being printed.

11. The system of claim 9 and wherein the plate comprises a plurality of spiral shaped grooves.

12. The system of claim 11 and wherein the plate further comprises an opaque coating below the plurality of grooves wherein the opaque coating is configured to prevent the transmission of light into the pool or the film through the plurality of grooves.

13. The system of claim 11 and wherein the plate comprises a plurality of conduits within the plate located below the plurality of grooves, wherein the plurality of conduits are configured to transport a cooling fluid.

14. The system of claim 1 wherein the relative movement actuator comprises a linear actuator configured to move the vessel in a linear direction relative to the part in an oscillating movement between the top surface of the plate and a bottom surface of the part.

15. The system of claim 14 and wherein the plate comprises a plurality of spaced apart and substantially parallel grooves and wherein the grooves are at an angle between about 5 degrees and about 90 degrees relative to the linear direction of the vessel.

16. The system of claim 15 and wherein the plate further comprises an opaque coating below the plurality of grooves wherein the opaque coating is configured to prevent the transmission of light into the pool or the film through the plurality of grooves.

17. The system of claim 15 and wherein the plate comprises a plurality of conduits within the plate located below the plurality of grooves, wherein the plurality of conduits are configured to transport a cooling fluid.

18. The system of claim 1 and wherein the light emitting device comprises a digital light projector.

19. The system of claim 1 and wherein the light emitting device comprises an array of lasers.

20. A method of manufacturing a part with an additive manufacturing process, the method comprising:

providing a continuous liquid interface production system comprising a substantially optically transparent plate within a vessel containing a pool or film of optically sensitive monomer, a source of optical stimulation configured to direct the optical stimulation through the optically transparent plate, a build platen configured to provide a bonding surface for the part being built, an actuator configured to raise the build platen and a controller configured to monitor a height of the build platen and to send a signal to cause the source to send optical stimulation through the plate and into the pool or the film to cause a layer of the part to be polymerized;

raising the build platen and the part being built in a direction substantially normal to a top surface of the plate while causing successive patterns of optical stimulation to be sent through the plate and into the pool or the film to build a portion of the part;

causing relative movement between the part and the plate in a direction substantially parallel to the top surface of the plate while raising the build platen, such that a viscosity pump effect is created between the part and the plate; and

causing a series of optical stimulations from the source to be emitted into the pool or the film through the plate to form additional layers of the part until the part is built.

21. The method of claim 20 and wherein the relative movement between the part and the plate is rotational movement of the part relative to a plate.

22. The method of claim 20 and wherein the relative movement between the part and the plate is linear movement of the plate relative to the part.