Debinding of 3D objects

Patent metadata

Field	Value
Publication number	US-10654102-B2
Application number	US-201916561568-A
Country	US
Kind code	B2
Filing date	Sep 5, 2019
Priority date	Dec 15, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

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

What is claimed is:

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

2. The method of claim 1 , wherein the sphere is a largest sphere capable of being entirely occupied within the internal volume of the printed part or the model of the printed part, and wherein the effective thickness is proportional to a radius of the largest sphere.

3. The method of claim 1 , wherein defining the size of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the printed part comprises:
generating a random sampling of points within a geometry of the printed part or the model of the printed 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 printed part; and
determining a maximum of the calculated distances.

4. The method of claim 3 , wherein the maximum of the calculated distances is proportional to the effective thickness of the printed part or the model of the printed part.

5. The method of claim 3 , 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 printed part.

6. The method of claim 1 , wherein defining the size of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the printed part comprises:
generating a grid of sampling points within a geometry of the printed part or the model of the printed 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 printed part; and
determining a maximum of the calculated distances.

7. The method of claim 6 , wherein the maximum of the calculated distances is proportional to the effective thickness of the printed part or the model of the printed part.

8. The method of claim 6 , 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 printed part.

9. The method of claim 1 , wherein a center of the sphere is a point within the internal volume of the printed part or the model of the printed part that is a maximum distance from any surface of the printed part or the model of the printed part.

10. The method of claim 1 , 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.

11. A method of determining a debinding time of a printed part or a model of a printed part, the method comprising:
receiving data about the printed part or the model of the printed part, wherein the data about the printed part or the model of the printed part includes toolpath instructions for printing the printed part or the model of the printed part;
determining an effective thickness of the printed part or the model of the printed part by defining a size of a sphere having a volume that is occupied within an internal volume of the printed part or the model of the printed part;
calculating the debinding time based on the effective thickness; and
debinding the printed part or a part generated based on the model of the printed part for the debinding time.

12. The method of claim 11 , wherein debinding the printed part or the part generated based on the model of the printed part includes delivering a debinding solution from a storage chamber to a chamber configured to receive the printed part or the part generated based on the model of the printed part.

13. The method of claim 11 , wherein defining the size of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the printed part comprises:
generating a random sampling of points within a geometry of the printed part or the model of the printed 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 printed part; and
determining a maximum of the calculated distances.

14. The method of claim 11 , wherein defining the size of the sphere having the volume that is occupied within the internal volume of the printed part or the model of the printed part comprises:
generating a grid of sampling points within a geometry of the printed part or the model of the printed 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 printed part; and
determining a maximum of the calculated distances.

15. The method of claim 11 , further comprising outputting, via a user interface, one or more of the debinding time, an indication of a debinding completion, or a current progress of the debinding.

16. A method of determining a debinding time of a printed part or a model of a printed part, the method comprising:
receiving data about the printed part or the model of the printed part;
determining an effective thickness of the printed part or the model of the printed part by defining a size of a sphere having a volume that is occupied within an internal volume of the printed part or the model of the printed part;
calculating the debinding time based on the effective thickness; and
debinding the printed part or a part generated based on the model of the printed part for the debinding time; and
outputting one or more of the debinding time, an indication of a debinding completion, or a current progress of the debinding.

17. The method of claim 16 , wherein a center of the sphere coincides with a point interior to the printed part or the model of the printed part that is a maximum distance from any surface of the printed part or the model of the printed part.

18. The method of claim 16 , wherein defining the size of the sphere includes:
generating a sampling of points from the printed part or the model of the printed 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 printed part; and
determining the radius of the sphere as a maximum of the calculated distances.

19. The method of claim 16 , 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
wherein calculating the debinding time includes calculating a time proportional to the effective thickness raised to the exponent.

20. The method of claim 16 , wherein debinding the printed part or the part generated based on the model of the printed part includes delivering a debinding solution from a storage chamber to a chamber configured to receive the printed part or the part generated based on the model of the printed

Assignees

• Desktop Metal Inc

Inventors

• Gibson Michael A
• Barbati Alexander C

Classifications

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• G01B21/08

  for measuring thickness · CPC title

• B29C64/386

  Data acquisition or data processing for 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

• B22F2202/07

  by induction · CPC title