Debinding of 3d objects

Patent metadata

Field	Value
Publication number	US-2020001363-A1
Application number	US-201916561568-A
Country	US
Kind code	A1
Filing date	Sep 5, 2019
Priority date	Dec 15, 2017
Publication date	Jan 2, 2020
Grant date	—

Abstract

3D-printed parts may include binding agents to be removed following an additive manufacturing process. A debinding process removes the binding agents by immersing the part in a solvent bath causing chemical dissolution of the binding agents. The time of exposure of the 3D-printed part to the solvent is determined based on the geometry of the part, wherein the geometry is applied to predict the diffusion of the solvent through the 3D-printed part. The 3D-printed part is then immersed in the solvent bath to remove the binding agent, and is removed from the solvent bath after the time of exposure.

First claim

1 - 20 . (canceled)

21 . A method of determining a debinding time of a printed part or a model of a part, the method comprising:
receiving data about the printed part or the model of the part; determining an effective thickness of the printed part or the model of the part by defining a geometry of a sphere having a volume that is occupied within an internal volume of the printed part or the model of the part; and calculating a debinding time based on the effective thickness.

22 . The method of claim 21 , wherein the sphere is a largest sphere capable of being entirely encompassed by the internal volume of the printed part or the model of the part, and wherein the effective thickness is proportional to a radius of the largest sphere.

23 . The method of claim 21 , wherein defining the geometry of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the part comprises:
generating a random sampling of points within a geometry of the printed part or the model of the part; calculating, for each of the points, a distance from the point to a closest surface of the printed part or the model of the part; and determining a maximum of the calculated distances.

24 . The method of claim 23 , wherein the maximum of the calculated distances is proportional to the effective thickness of the printed part or the model of the part.

25 . The method of claim 23 , wherein a point of the random sampling of points that corresponds to the maximum of the calculated distances is used as the center point of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the part.

26 . The method of claim 21 , wherein defining the geometry of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the part comprises:
generating a grid of sampling points within a geometry of the printed part or the model of the part; calculating, for each of the points, a distance from the point to a closest surface of the printed part or the model of the part; and determining a maximum of the calculated distances.

27 . The method of claim 26 , wherein the maximum of the calculated distances is proportional to the effective thickness of the printed part or the model of the part.

28 . The method of claim 26 , wherein a point of the grid of sampling points that corresponds to the maximum of the calculated distances is used as the center point of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the part.

29 . The method of claim 21 , wherein a center of the sphere is a point within the internal volume of the printed part or the model of the part that is a maximum distance from any surface of the printed part or the model of the part.

30 . The method of claim 21 , wherein calculating the debinding time proportional to the effective thickness includes raising the effective thickness to an exponent greater than or equal to 1 and less than or equal to 2.4.

31 . A system for debinding a printed part, the system comprising:
a chamber configured to receive the printed part; a storage chamber fluidly connected to the chamber and configured to store a debinding solution; and a controller configured to calculate a debinding time for the printed part or a model of a printed part, wherein calculating the debinding time includes: determining an effective thickness of the printed part or the model of the part by defining a geometry of a sphere having a volume that is encompassed by an internal volume of the printed part or the model of the part, wherein the effective thickness is proportional to a radius of the sphere; and calculating a debinding time based on the effective thickness.

32 . The system of claim 31 , wherein defining the geometry of the sphere having the volume that is encompassed by the internal volume of the printed part or the model of the part comprises:
generating a random sampling of points within a geometry of the printed part or the model of the part; and calculating, for each of the points, a distance from the point to a closest exterior surface of the printed part or the model of the part; and determining a maximum of the calculated distances.

33 . The system of claim 31 , wherein defining the geometry of the sphere having the volume that is encompassed by the internal volume of the printed part or the model of the part comprises:
generating a grid of sampling points within a geometry of the printed part or the model of the part; and calculating, for each of the points, a distance from the point to a closest surface of the printed part or the model of the part; and determining a maximum of the calculated distances.

34 . The system of claim 31 , wherein the controller is configured to calculate the debinding time for a plurality of printed parts or a plurality of models of parts, and wherein the controller is configured to determine the debinding time by determining a longest debinding time of the debinding times calculated for each of the plurality of printed parts or each of the plurality of models of parts.

35 . The system of claim 31 , further comprising:
a user interface operably coupled to the controller and configured to display one or more indications of the debinding.

36 . The system of claim 31 , further comprising:
a distill chamber fluidly connected to the process chamber; a waste chamber fluidly connected to the distill chamber; and a condenser fluidly connected to both the distill chamber and the storage chamber.

37 . A non-transitory computer readable medium for use on a computer system containing computer-executable programming instructions for performing a method of determining a debinding time of a printed part or a model of a part, the method comprising:
receiving data about the printed part or the model of the part; determining an effective thickness of the printed part or the model of the part by defining a geometry of a sphere having a volume that is encompassed by an internal volume of the printed part or the model of the part; and calculating a debinding time based on the effective thickness.

38 . The non-transitory computer readable medium of claim 37 , wherein a center of the sphere coincides with a point interior to the printed part or the model of the part that is a maximum distance from any surface of the printed part or the model of the part.

39 . The non-transitory computer readable medium of claim 37 , wherein defining the geometry of the sphere includes:
generating a sampling of points from the printed part or the model of the part; calculating, for each of the points, a distance from the point to a closest surface of the printed part or the model of the part; and determining the radius of the sphere as a maximum of the calculated distances.

40 . The non-transitory computer readable medium of claim 37 , further comprising:
raising the effective thickness to a power having an exponent greater than or equal to 1 and less than or equal to 2.4; and calculating a time proportional to the effective thickness raised to the exponent.

Assignees

• Desktop Metal Inc

Inventors

• Gibson Michael A
• Barbati Alexander C

Classifications

• B22F2202/01

  Use of vibrations · CPC title

• B29C64/40

  Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B22F2203/00

  Controlling · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title