Debinding of 3d objects

Patent metadata

Field	Value
Publication number	US-2020061706-A1
Application number	US-201916561689-A
Country	US
Kind code	A1
Filing date	Sep 5, 2019
Priority date	Dec 15, 2017
Publication date	Feb 27, 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, wherein the printed part or the model of the part includes an outer shell and an interior structure having a plurality of cells forming a honeycomb structure having an axis of symmetry; determining a length of a longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure; and calculating a debinding time based on the length of the longest cell.

22 . The method of claim 21 , wherein determining the debinding time further includes a proportional scaling relative to an inverse of a thickness of the outer shell.

23 . The method of claim 21 , wherein determining the debinding time further includes a proportional scaling relative to an area of solid material in a plane of symmetry of the honeycomb structure.

24 . The method of claim 21 , wherein determining the length of the longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure includes calculating a distance field in a geometry of the printed part or the model of the part.

25 . The method of claim 24 , wherein calculating the distance field in the geometry of the printed part or the model of the part includes calculating a vertical distance field in the geometry by:
calculating distances in a vertically downward direction between all upward facing surfaces to another surface of the printed part or the model of the part; and determining a maximum distance of the calculated distances.

26 . The method of claim 25 , wherein calculating the length of the longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure further includes subtracting thicknesses of top and bottom layers of the plurality of cells.

27 . The method of claim 21 , wherein each of the cells forming the honeycomb structure include cellular walls with a uniform size or a uniform shape.

28 . The method of claim 21 , wherein the plurality of cells each include a hexagonal cell shape in a plane.

29 . The method of claim 21 , wherein calculating the debinding time based on the length of the longest cell includes raising the length of the longest cell to an exponential power that is greater than or equal to 1 and less than or equal to 2.4, and calculating the debinding time proportional to the length of the longest cell raised to the exponential power.

30 . The method of claim 21 , comprising receiving data about a plurality of printed parts or a plurality of models of parts, and wherein calculating the debinding time is based on the length of the longest cell of the plurality of printed parts or the plurality of models of parts.

31 . A system for debinding a printed part, comprising:
a chamber configured to receive the printed part; a storage chamber fluidly connected to the process 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 part, wherein the printed part or the model of the part includes an outer shell and an interior structure having a plurality of cells forming a honeycomb structure having an axis of symmetry, wherein calculating the debinding time includes:
determining a length of a longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure; and
calculating a debinding time based on the length of the longest cell.

32 . The system of claim 31 , wherein determining the length of the longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure includes calculating a distance field in a geometry of the printed part or the model of the part by:
calculating distances in a vertically downward direction between all upward facing surfaces to another surface of the printed part or the model of the part and subtracting thicknesses of top and bottom layers of the plurality of cells; and determining a maximum distance of the calculated distances.

33 . The system of claim 31 , wherein determining the debinding time further includes a proportional scaling relative to an inverse of a thickness of the outer shell.

34 . The system of claim 31 , wherein determining the debinding time further includes a proportional scaling relative to an area of solid material in a plane of symmetry of the honeycomb structure.

35 . The system of claim 31 , wherein the controller is configured to calculate a 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 for each of the plurality of printed parts or the plurality of models of parts.

36 . The system of claim 31 , further comprising:
a user interface, wherein the controller is configured to signal the user interface to display one or more indications of the debinding.

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, wherein the printed part or the model of the part includes an outer shell and an interior structure having a plurality of cells forming a honeycomb structure having an axis of symmetry; determining a length of a longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure; and calculating a debinding time based on the length of the longest cell.

38 . The non-transitory computer readable medium of claim 37 , wherein determining the debinding time further includes a proportional scaling relative to an inverse of a thickness of the outer shell and a proportional scaling relative to an area of solid material in a plane of symmetry of the honeycomb structure.

39 . The non-transitory computer readable medium of claim 37 , wherein determining the length of the longest cell of the plurality of cells along the axis of symmetry of the honeycomb structure includes calculating a distance field in a geometry of the printed part or the model of the part by:
calculating distances in a vertically downward direction between all upward facing surfaces to another surface of the printed part or the part to be printed and subtracting thicknesses of top and bottom layers of the plurality of cells; and determining a maximum distance of the calculated distances.

40 . The non-transitory computer readable medium of claim 37 , further comprising:
raising the length of the longest cell 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 length of the longest cell raised to the exponent.

Assignees

• Desktop Metal Inc

Inventors

• Gibson Michael A
• Barbati Alexander C

Classifications

• B29C64/357

  Recycling · CPC title

• B08B3/08

  the liquid having chemical or dissolving effect · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C71/0009

  using liquids, e.g. solvents, swelling agents (spectacle cases, e.g. for cleaning contact lenses A45C11/04; disinfecting or sterilising contact lenses A61L12/00, using liquid substances A61L2/20; cleaning involving the use of liquid in general B08B3/00; for hydrating contact lenses B29D11/00067) · CPC title

• B22F2203/00

  Controlling · CPC title