Fabrication of 3d objects via multiple build platforms

Abstract

A method is disclosed for improving the productivity of digitally fabricated 3D objects with the same or different shape and material composition. The improved productivity is enabled by the incorporation of multiple build platforms and multiple objects per build platform within a 3D object fabrication apparatus. Some 3D manufacturing processes such as those based on electrophotography require a wait time to condition the build object before the next layer of build and support material can be applied. Under these fabrication conditions, the utilization of multiple build platforms in the 3D object manufacturing process effectively minimizes the wait time between layer deposition so that the productivity for fabricating 3D objects is improved. Furthermore, the incorporation of an additional adjacent set of multiple platforms enables rapid changeover when the fabrication of one set of 3D objects is completed on an adjacent set of build platforms.

We claim: 
     
         1 . A method of fabricating a plurality of objects, the method comprising:
 a) depositing a first powder layer on a surface of a first object substrate on a first build platform located at a material transfer station;   b) consolidating the first powder layer on the first object substrate to form a first solid layer of a first object on the first object substrate;   c) locating a second object substrate on a second build platform at the material transfer station following removal of the first build platform with the first object substrate from the material transfer station;   d) depositing a first powder layer on the surface of the second object substrate;   e) consolidating the first powder layer on the second object substrate to form a first solid layer of a second object on the second object substrate; and   f) removing the second build platform with the second object substrate from the material transfer station.   
     
     
         2 . The method of  claim 1 , wherein consolidating the first powder layer on the first object substrate to form the first solid layer of the first object on the first object substrate is performed after the removing the first build platform with the first object substrate from the material transfer station, and consolidating the first powder layer on the second object substrate to form the first solid layer of the second object on the second object substrate is performed after removing the second build platform with the second object substrate from the material transfer station. 
     
     
         3 . The method of  claim 1 , wherein consolidating the first powder layer on the first object substrate to form the first solid layer of the first object on the first object substrate and consolidating the first powder layer on the second object substrate to form the first solid layer of the second object on the second object substrate are performed at the material transfer station. 
     
     
         4 . The method of  claim 3 , wherein consolidating the first powder layer on the first object substrate is performed during depositing the first powder layer on the surface of the first object substrate, and consolidating the first powder layer on the second object substrate is performed during depositing the first powder layer on the surface of the second object substrate. 
     
     
         5 . The method of  claim 1 , wherein consolidating the first powder layer on the first object substrate and consolidating the first powder layer on the second object substrate are performed after depositing the first powder layer on the surface of the first object substrate and depositing the first powder layer on the surface of the second object substrate. 
     
     
         6 . The method of  claim 1 , further comprising first depositing the first powder layer deposited on the surface of the first object substrate on a surface of an intermediate substrate, moving that first powder layer on the surface of the first intermediate substrate to the first build platform located at the material transfer station prior to depositing the first powder layer on the surface of the first object substrate; and first depositing the first powder layer deposited on the surface of the second object substrate on the surface of the intermediate substrate, moving that first powder layer on the surface of the intermediate substrate to the second build platform located at the material transfer station prior to depositing that first powder layer on the surface of the second object substrate. 
     
     
         7 . The method of  claim 6 , wherein the intermediate substrate is a belt substrate. 
     
     
         8 . The method of  claim 6 , wherein the intermediate substrate is a drum substrate. 
     
     
         9 . The method of  claim 6 , wherein the first powder layer deposited on the surface of the first object substrate and the first powder layer deposited on the surface of the second object substrate are first deposited on the surface of the intermediate substrate by an electrophotographic process. 
     
     
         10 . The method of  claim 6 , further comprising pre-conditioning, on the surface of the intermediate substrate, the first powder layer deposited on the surface of the first object substrate and the first powder layer deposited on the surface of the second object substrate prior to depositing the first powder layer on the surface of the first object substrate and depositing the first powder layer on the surface of the second object substrate. 
     
     
         11 . The method of  claim 1 , further comprising post-conditioning the first solid layer of the first object on the first object substrate and the first solid layer of the second object on the second object substrate. 
     
     
         12 . The method of  claim 1 , further comprising pre-conditioning the first solid layer of the first object on the first object substrate and the first solid layer of the second object on the second object substrate. 
     
     
         13 . The method of  claim 1 , further comprising:
 a) moving the first build platform with the first object substrate and first solid layer of the first object to the material transfer station;   b) depositing a second powder layer on the first solid layer of the first object;   c) consolidating the second powder layer with the first solid layer of the first object;   d) locating the second build platform with the second object substrate and first solid layer of the second object at the material transfer station following removal of the first build platform with the first object substrate from the material transfer station;   e) depositing a second powder layer on the first solid layer of the second object;   f) consolidating the second powder layer deposited on the first solid layer of the second object with the first solid layer of the second object; and   g) removing the second build platform with the second object substrate from the material transfer station.   
     
     
         14 . The method of  claim 13 , wherein the first object and second object are each comprised of h consolidated layers, the method further comprising repeating h−2 times:
 a) moving the first build platform with the first object substrate and consolidated solid layers of the first object to the material transfer station; 
 b) depositing an additional powder layer on the consolidated solid layers of the first object; 
 c) consolidating the additional powder layer with the consolidated solid layers of the first object; 
 d) locating the second build platform with the second object substrate and consolidated solid layers of the second object at the material transfer station following removal of the first build platform with the first object substrate and consolidated solid layers of the first object from the material transfer station; 
 e) depositing an additional powder layer on the consolidated solid layers of the second object; 
 f) consolidating the additional powder layer with the consolidated solid layers of the second object; and 
 g) removing the second build platform with the second object substrate from the material transfer station. 
 
     
     
         15 . The method of  claim 13 , wherein the movings and removings of the first build platform to and from the material transfer station, and movings and removings of the second build platform to and from the material transfer station are performed using linear pathways. 
     
     
         16 . The method of  claim 13  wherein the movings and removings of the first build platform, and movings and removings of the second build platform are performed along a first cyclic loop pathway in communication with the material transfer station in a first loop direction. 
     
     
         17 . The method of  claim 1 , further comprising providing a third build platform and a fourth build platform adjacent to the first build platform and the second build platform, the third and fourth build platforms movable relative to the material transfer station along a second cyclic loop pathway. 
     
     
         18 . The method of  claim 17 , wherein the second cyclic loop pathway is in a second loop direction that is opposite the first loop direction. 
     
     
         19 . The method of  claim 17 , further comprising:
 a) disposing a third object substrate on the third build platform;   b) disposing a fourth object substrate on the fourth build platform;   c) moving the first build platform and first object substrate and first solid layer of the first object and the second build platform and second object substrate and first solid layer of the second object relative to the material transfer station to a distal location wherein the first cyclic loop pathway is not in communication with the material transfer station;   d) moving the third build platform and third object substrate and moving the fourth build platform and fourth substrate relative to the material transfer station to a proximal location wherein the second loop pathway is in communication with the material transfer station;   e) locating the third build platform and third object substrate at the material transfer station, depositing a first powder layer on the surface of the third object substrate and consolidating the first powder layer on the third object substrate to form a first solid layer of the third object on the third object substrate; and   f) locating the fourth build platform and fourth object substrate at the material transfer station following removal of the third build platform with the third object substrate from the material transfer station, depositing a first powder layer on the surface of the fourth object substrate and consolidating the first powder layer on the fourth object substrate to form a first solid layer of the fourth object on the fourth object substrate.   
     
     
         20 . The method of  claim 1 , wherein the first and second build platforms are joined to an outer surface of a cylinder having an axis of rotation equidistant from all points on the outer surface, and the method further comprises rotating the cylinder about its axis of rotation to cause the locating of the first build platform, first object substrate and first powder layer of the first object at the material transfer station, and to cause the removal of the first build platform with the first object substrate and first solid layer of the first object from the material transfer station, and to cause the locating of the second build platform, second object substrate and first powder layer of the second object at the material transfer station, and to cause the removal of the second build platform with the second object substrate and first solid layer of the second object from the material transfer station. 
     
     
         21 . The method of  claim 20 , wherein n build platforms are joined to the surface of the cylinder, the method comprising:
 a) for each of the n−2 additional object build platforms, rotating the cylinder about its axis of rotation to cause the locating of the build platform, the object substrate and the powder layer of the object on that build platform at the material transfer station;   b) consolidating the powder layer on the object substrate to form a first solid layer of the object on the object substrate on that build platform; and   c) rotating the cylinder about its axis of rotation to cause the removal of that build platform with the object substrate and solid layer of the object on that build platform from the material transfer station.   
     
     
         22 . The method of  claim 1 , wherein the number of object build platforms is n, the method comprising for each of the n−2 additional object build platforms:
 a) depositing a powder layer on a surface of an additional object substrate on an additional build platform located at the material transfer station; 
 b) consolidating the powder layer on the additional object substrate to form a first solid layer of the additional object on the additional object substrate; and 
 c) removing the additional build platform with the additional object substrate from the material transfer station. 
 
     
     
         23 . The method of  claim 22 , wherein the first object, the second object, and the n−2 additional objects are each comprised of h consolidated layers, the method further comprising, for each of the first build platform, second build platform, and additional build platforms, repeating h−1 times:
 a) selecting a chosen build platform from one of the first build platform, second build platform, and additional build platforms, and moving the chosen build platform with object substrate and consolidated solid layers of the object on the chosen build platform to the material transfer station; 
 b) depositing an additional powder layer on the consolidated solid layers of the object on the chosen build platform; 
 c) consolidating the additional powder layer with the consolidated solid layers of the object on the chosen build platform; and 
 d) removing the chosen build platform from the material transfer station. 
 
     
     
         24 . An apparatus for making a plurality of objects, the apparatus comprising:
 a) a plurality of object substrates, each of the substrates comprising a powder receiving surface;   b) a plurality of build platforms, each of the build platforms engageable with any one of the object substrates;   c) a material transfer station comprised of a fixture engageable with any one of the build platforms;   d) a transporting device engaged with each of the build platforms and operable to repeatedly transport each of the build platforms to and from the material transfer station; and   e) a powder layering device operable to dispense a layer of powder onto one of the powder receiving surface or a consolidated layer of powder on the powder receiving surface of any one of the object substrates when that object substrate is located at the material transfer station.   
     
     
         25 . The apparatus of  claim 24 , wherein the powder layering device is comprised of a powder layer generating device operable to dispense a powder layer onto a powder layer transfer device comprising a transfer substrate having a surface movable between the powder layer generating device and the material transfer station. 
     
     
         26 . The apparatus of  claim 25 , wherein the powder layer transfer device substrate is comprised of a belt substrate. 
     
     
         27 . The apparatus of  claim 25 , wherein the powder layer transfer device substrate is a drum substrate. 
     
     
         28 . The apparatus of  claim 25 , wherein the powder layer generating device is an electrophotographic imaging engine. 
     
     
         29 . The apparatus of  claim 24 , wherein the transporting device transports the build platforms to and from the material transfer station in linear pathways. 
     
     
         30 . The apparatus of  claim 24 , wherein the transporting device transports the build platforms to and from the material transfer station in cyclic loop pathways. 
     
     
         31 . The apparatus of  claim 30 , wherein the transporting device is comprised of:
 a) a first conveyor engaged with a first portion of the build platforms and operable to transport the first portion of the build platforms to and from the material transfer station in a first cyclic loop pathway; and   b) a second conveyor adjacent to the first conveyor and engaged with a second portion of the build platforms and operable to transport the second portion of the build platforms to and from the material transfer station in a second cyclic loop pathway.   
     
     
         32 . The apparatus of  claim 24 , wherein the transporting device is a cylinder comprising an outer surface and having an axis of rotation equidistant from all points on the outer surface, and each of the build platforms are joined to the outer surface of the cylinder, and wherein the cylinder is rotatable around its axis of rotation to transport each of the build platforms to and from the material transfer station. 
     
     
         33 . The apparatus of  claim 24 , wherein:
 a) the transporting device is comprised of a first cylinder and a second cylinder, each of the first and second cylinders comprising an outer surface and having an axis of rotation equidistant from all points on the outer surface of that cylinder;   b) a first portion of the build platforms are joined to the outer surface of the first cylinder, and the first cylinder is movable to a location proximate to the material transfer station and rotatable around its axis of rotation to transport each of the build platforms of the first portion of the build platforms to and from the material transfer station; and   c) a second portion of the second cylinder is movable to the location proximate to the material transfer station and rotatable around its axis of rotation to transport each of the build platforms of the second portion of the build platforms to and from the material transfer station.