Powder dispensing in binder jetting for additive manufacturing

Patent metadata

Field	Value
Publication number	US-2018304358-A1
Application number	US-201815959096-A
Country	US
Kind code	A1
Filing date	Apr 20, 2018
Priority date	Apr 21, 2017
Publication date	Oct 25, 2018
Grant date	—

Abstract

The devices, systems, and methods of the present disclosure are directed to dispensing powder for rapid and accurate layer-by-layer fabrication of three-dimensional objects formed through binder jetting. More specifically, a powder may be dispensed from a hopper movable over a volume defined by a powder box to facilitate, for example, rapidly delivering powder in front of a spreader movable across the volume to spread the powder into a layer. The hopper may include a plurality of dispensing rollers along a dispensing region of the hopper. The dispensing rollers may be rotatable relative to one another to control dispensing the powder from the hopper to an area in front of the spreader, reducing wasted motion associated with moving a spreader to retrieve powder from a stationary powder supply and reducing the likelihood of inadvertently delivering powder from the hopper to unintended areas.

First claim

What is claimed is:

1 . An additive manufacturing system comprising:
a print box defining a volume; a print carriage movable over the volume, the print carriage defining at least one ejection orifice directed toward the volume as the print carriage moves over the volume; a spreader movable over the volume in advance of the print carriage; and a hopper movable over the volume in advance of the spreader, the hopper defining a dispensing region, the hopper including a plurality of dispensing rollers along the dispensing region, and the plurality of dispensing rollers rotatable relative to one another to move a powder through the dispensing region and toward the volume in advance of the spreader as the spreader moves toward a position over the volume to form a layer of the powder, onto which a binder is deliverable from the at least one ejection orifice of the print carriage trailing the spreader over the volume.

2 . The system of claim 1 , wherein dispensing rollers of the plurality of dispensing rollers are spaced apart from one another to define a gap, and the plurality of dispensing rollers are rotatable relative to one another to move the powder through the gap and toward the volume.

3 . The system of claim 2 , wherein the dispensing region of the hopper spans a dimension of the volume substantially parallel to the gap as the hopper moves over the volume.

4 . The system of claim 3 , wherein the plurality of dispensing rollers span the dimension of the volume as the hopper moves over the volume.

5 . The system of claim 1 , wherein each dispensing roller of the plurality of dispensing rollers has a substantially similar diameter.

6 . The system of claim 1 , further comprising at least one motor mechanically coupled to one or more dispensing rollers of the plurality of dispensing rollers, the at least one motor actuatable to rotate the plurality of dispensing rollers relative to one another.

7 . The system of claim 6 , wherein the at least one motor is actuatable to rotate the plurality of dispensing rollers in a counter-rotating direction relative to one another.

8 . The system of claim 6 , further comprising a controller in electrical communication with the at least one motor, the controller configured to actuate the at least one motor based on movement of the hopper over the volume.

9 . The system of claim 8 , wherein the controller is configured to actuate the at least one motor in a first direction of movement of the hopper over the volume and to pause actuation of the at least one motor in a second direction of movement of the hopper over the volume, the second direction of movement different from the first direction of movement.

10 . The system of claim 8 , wherein the controller is configured to actuate the at least one motor based on speed of movement of the hopper over the volume.

11 . The system of claim 8 , wherein the controller is configured to actuate the at least one motor to rotate the plurality of dispensing rollers at substantially the same rotation speed.

12 . The system of claim 6 , wherein the hopper includes a storage region in fluid communication with the dispensing region, the powder movable from the storage region toward the dispensing region through force of gravity as the hopper moves over the volume.

13 . The system of claim 6 , wherein the hopper includes a shutter selectively movable between a first position away from the dispensing region to a second position below the dispensing region to interrupt movement of powder exiting the hopper via the dispensing region.

14 . The system of claim 13 , wherein the shutter is selectively movable between the first position and the second position based on rotation of dispensing rollers of the plurality of dispensing rollers.

15 . A method of additive manufacturing of an object, the method comprising:
moving a hopper over a volume defined by a print box; as the hopper moves over the volume, rotating a plurality of dispensing rollers disposed along a dispensing region defined by the hopper, the rotation of the plurality of dispensing rollers moving a powder toward the volume from the dispensing region; spreading the powder along the volume to form a layer of the powder; and in a controlled two-dimensional pattern, ejecting a binder from at least one ejection orifice of a print carriage to the layer of the powder to form a portion of the object.

16 . The method of claim 15 , wherein rotation of the plurality of dispensing rollers moves the powder toward the volume through a gap defined between the plurality of dispensing rollers.

17 . The method of claim 16 , wherein the gap and the dispensing region span a dimension of the volume substantially perpendicular to a direction of movement of the hopper over the volume.

18 . The method of claim 15 , wherein rotating the plurality of dispensing rollers includes counter-rotating dispensing rollers of the plurality of dispensing rollers.

19 . The method of claim 15 , wherein rotating the plurality of dispensing rollers includes controlling a rotation speed of at least one dispensing roller of the plurality of dispensing rollers based on a speed of movement of the hopper over the volume.

20 . The method of claim 15 , wherein rotating the plurality of dispensing rollers includes controlling a rotation speed of at least one dispensing roller of the plurality of dispensing rollers based on position of the hopper over the volume.

21 . The method of claim 20 , wherein controlling the rotation speed of the at least one dispensing roller includes reducing the rotation speed of the at least one dispensing roller as the hopper moves from a first side of the volume to a second side of the volume, the second side of the volume opposite the first side of the volume.

22 . The method of claim 15 , wherein rotating the plurality of dispensing rollers includes rotating each dispensing roller of the plurality of dispensing rollers at substantially the same rotation speed.

23 . The method of claim 15 , wherein rotating the plurality of dispensing rollers includes controlling a rotation speed of each dispensing roller of the plurality of dispensing rollers based on a direction of movement of the hopper over the volume.

Assignees

• Desktop Metal Inc

Inventors

• Myerberg Jonah Samuel
• Fulop Ricardo
• Hoisington Paul A
• Sachs Emanuel Michael
• Hart Anastasios John
• Vaillancourt Keith
• Garrant Steven
• SCHUSTER Brett
• Hudelson George

Classifications

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B22F2202/01

  Use of vibrations · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• B22F2998/00

  Supplementary information concerning processes or compositions relating to powder metallurgy · CPC title