A three-dimensional part and associated support structure is constructed using an electrophotography-based additive manufacturing system. A support layer is developed using a first electrophotography engine, and a part layer is developed using a second electrophotography engine. The developed support and part layers are transferred to a transfer medium and moved into alignment with a tile region of a layer transfusion assembly, where the transferred part and support layers are transfused to previously-printed layers. This process is repeated for a plurality tile regions and for a plurality of layers to construct a three-dimensional part having a footprint larger than a maximum printable area of the first and second electrophotography engines.

An additive manufacturing method produces a 3D part utilizes electrophotography-based additive manufacturing and molding processes. A layered structure having a cavity is printed on a build platform using at least one electrophotographic (EP) engine to develop imaged layers of powder material, and a transfusion assembly to stack and fuse the imaged layers on the build platform. Molding material is deposited into the cavity as the layered structure is printed, using a deposition unit. The molding material solidifies to form at least a portion of the 3D part, which may also include portions formed from imaged powder material.

3-D printing transfers build material and support from an intermediate transfer belt (ITB) to a platen. The build material is the same as the support material, except that the build material includes a photoinitiator and the support material does not. The platen moves to make contact with the ITB, and the ITB transfers successive layers of build material and support material each time the platen contacts the ITB. The platen and a portion of the ITB that is adjacent the platen are heated prior to the platen contacting the ITB, and the same is exposed so as to crosslink polymers of build material, without crosslinking polymers of support material. The polymers of build material being crosslinked and the polymers of support material not being crosslinked makes the support material selectively soluble in a solvent.

A method for printing a three-dimensional part and a support structure with an electrophotography-based additive manufacturing system. The method includes developing a support layer of the support structure from a soluble support material with a first electrophotography engine, and transferring the developed support layer from the first electrophotography engine to a transfer medium. The method also includes developing a part layer of the three-dimensional part from an ABS part material with a second electrophotography engine, and transferring the developed part layer from the second electrophotography engine to the transfer medium. The method further includes moving the attracted part and support layers to a layer transfusion assembly with the transfer medium, and transfusing the moved part and support layers together to previously-printed layers with the layer transfusion assembly.

A method of printing three-dimensional parts with an electrophotography-based additive manufacturing system, with a part material including a composition having an engineering-grade thermoplastic material and a charge control agent. The part material is provided in a powder form having a controlled particle size, and is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the three-dimensional parts in a layer-by-layer manner.

A support material for printing a support structure with an electrophotography-based additive manufacturing system, the support material including a composition having a charge control agent and a thermoplastic copolymer having aromatic groups, (meth)acrylate-based ester groups, carboxylic acid groups, and anhydride groups, with a high anhydride conversion. The composition is provided in a powder form having a controlled particle size, and the support material is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the support structure in a layer-by-layer manner, and is at least partially soluble in an aqueous solution.

A method for printing a three-dimensional part with an additive manufacturing system includes providing a bitslice stack having a plurality of bitslices and printing a plurality of successive layers of the three-dimensional part with the additive manufacturing system based on the bitslices in the bitslice stack. The method includes measuring density of the three-dimensional part under construction near an intermediate build surface after one or more of the successive layers are printed. The method includes determining differences across the intermediate build surface of the measured density to a targeted density to identify one or more density error regions across the intermediate build surface, wherein the density error regions comprise low density regions, and modifying the bitslice stack to compensate for the one or more density error regions.

A water dispersible sulfopolymer for use as a material in the layer-wise additive manufacture of a 3D part made of a non water dispersible polymer wherein the water dispersible polymer is a reaction product of a metal sulfo monomer, the water dispersible sulfo-polymer being dispersible in water resulting in separation of the water dispersible polymer from the 3D part made of the non water dispersible polymer.

A 3-D printer includes a development station positioned to electrostatically transfer layers of material to an intermediate transfer surface, and a transfuse station adjacent the intermediate transfer surface. The transfuse station is positioned to receive the layers as the intermediate transfer surface moves past the transfuse station. Also, a platen is included that moves relative to the intermediate transfer surface. The intermediate transfer surface transfers a layer of the material to the platen each time the platen contacts one of the layers on the intermediate transfer surface at the transfuse station to successively form a freestanding stack of the layers on the platen. A curing station is positioned to apply ultraviolet light to each layer, after each layer is transferred from the transfuse station to the platen. The curing station selectively applies the ultraviolet light to crosslink polymers only in a portion of the material within the layer.

A part material for printing three-dimensional parts with an electrophotography-based additive manufacturing system, the part material including a composition having a copolymer (including acrylonitrile units, butadiene units, and aromatic units), a charge control agent, and a heat absorber. The part material is provided in a powder form having a controlled particle size, and is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the three-dimensional parts in a layer-by-layer manner.