Debinding of 3D Printed Objects

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.

1 - 20 . (canceled) 
     
     
         21 . A method of determining a debinding time of a printed part or a part to be printed, the method comprising:
 receiving data about the printed part or the part to be printed, wherein the printed part or the part to be printed includes a build material and a binding agent;   determining an effective thickness of the printed part or the part to be printed;   raising the effective thickness to a power having an exponent greater than 1; and   calculating a time proportional to the effective thickness raised to the exponent.   
     
     
         22 . The method of  claim 21 , wherein the effective thickness corresponds to a distance from a deepest point to a nearest exterior surface of the printed part or the part to be printed from the deepest point, the deepest point being a point interior to the printed part or the part to be printed that is a maximum distance from any exterior surface of the printed part or the part to be printed. 
     
     
         23 . The method of  claim 21 , wherein determining the effective thickness includes identifying a point interior to the printed part or the part to be printed that is a maximum distance from any exterior surface of the printed part or the part to be printed, the effective thickness being a linear function of the maximum distance. 
     
     
         24 . The method of  claim 21 , wherein determining the effective thickness includes:
 defining a geometry of a sphere, the sphere having a volume that is entirely encompassed by an internal volume of the printed part or the part to be printed,   wherein the effective thickness is a radius of the sphere.   
     
     
         25 . The method of  claim 24 , wherein the sphere is a largest sphere that can be entirely encompassed by the internal volume of the printed part or the part to be printed. 
     
     
         26 . The method of  claim 24 , wherein defining the geometry of the sphere includes:
 producing a sampling of points from the printed part or the part to be printed;   calculating, for each of the points, a distance from the point to a closest exterior surface of the printed part or the part to be printed; and   determining the radius of the sphere as a maximum of the calculated distances.   
     
     
         27 . The method of  claim 24 , wherein defining the geometry of the sphere includes:
 generating a uniform grid sampling of points in the printed part or the part to be printed;   calculating, for each of the points, a distance from the point to a closest exterior surface of the printed part or the part to be printed; and   determining the radius of the sphere as a maximum of the calculated distances for each of the points.   
     
     
         28 . The method of  claim 24 , wherein a center of the sphere coincides with a point interior to the printed part or the part to be printed that is a maximum distance from any exterior surface of the printed part or the part to be printed. 
     
     
         29 . The method of  claim 21 , wherein determining the effective thickness of the printed part or the part to be printed includes:
 defining a geometry of a series of reduced parts within the printed part or the part to be printed, wherein defining the geometry of each of the reduced parts includes 1) occupying an internal volume of the printed part or the part to be printed and 2) producing a geometry corresponding to a displacement of an exterior surface inward along a local normal vector of the exterior surface relative to a geometry of a preceding reduced part;   identifying a distance from an exterior surface of the part or the part to be printed to an exterior surface of one of the reduced parts; and   determining the effective thickness based on the distance.   
     
     
         30 . The method of  claim 21 , wherein the exponent is greater than or equal to 1 and less than or equal to 2.4,
 wherein the build material includes a powdered material, and   wherein the binding agent includes a polymer that is at least partially dissolvable when immersed in a solvent.   
     
     
         31 . The method of  claim 21 , further including grouping a plurality of printed parts or parts to be printed for debinding based at least in part on one or more properties of the plurality of printed parts or parts to be printed. 
     
     
         32 . A method of determining a debinding time for a printed part or a part to be printed, the method comprising:
 receiving data about the printed part or the part to be printed, wherein the printed part or the part to be printed includes a build material and a binding agent, and wherein the printed part or the part to be printed 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;   raising the length of the longest cell of the plurality of cells to an exponential power; and   calculating a time proportional to the length of the longest cell raised to the exponential power.   
     
     
         33 . The method of  claim 32 , wherein the exponential power is greater than or equal to 1 and less than or equal to 2.4. 
     
     
         34 . The method of  claim 32 , wherein determining the debinding time further includes a proportional scaling relative to an inverse of a thickness of the outer shell. 
     
     
         35 . The method of  claim 32 , 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. 
     
     
         36 . A method of determining a debinding time of a printed part or a part to be printed, the method comprising:
 receiving data about the printed part or the part to be printed, wherein the printed part or the part to be printed includes a build material and a binding agent;   determining an effective thickness of the printed part or the part to be printed by defining a geometry of a sphere having a volume that is entirely encompassed by an internal volume of the printed part or the part to be printed;   raising the effective thickness to a power having an exponent greater than 1; and   calculating a time proportional to the effective thickness raised to the exponent.   
     
     
         37 . The method of  claim 36 , wherein the sphere is a largest sphere that can be entirely encompassed by the internal volume of the printed part or the part to be printed, and wherein a center of the sphere coincides with a point interior to the printed part or the part to be printed that is a maximum distance from any exterior surface of the printed part or the part to be printed. 
     
     
         38 . The method of  claim 36 , wherein defining the geometry of the sphere includes:
 producing a sampling of points from the printed part or the part to be printed;   calculating, for each of the points, a distance from the point to a closest exterior surface of the printed part or the part to be printed; and   determining the radius of the sphere as a maximum of the calculated distances.   
     
     
         39 . The method of  claim 36 , wherein defining the geometry of the sphere includes:
 generating a uniform grid sampling of points in the printed part or the part to be printed;   calculating, for each of the points, a distance from the point to a closest exterior surface; and   determining the radius of the sphere as a maximum of the calculated distances.   
     
     
         40 . The method of  claim 36 , wherein the exponent is greater than or equal to 1 and less than or equal to 2.4.