Abstract: Embodiments herein relate to 3D printing. In an embodiment, a method for printing an article using a selective toner electrophotographic process (“STEP”) includes successively depositing multiple layers of part material and support material, the layers deposited substantially parallel to a first plane; wherein: a) the multiple layers of part material and support material extend in a perpendicular to the first plane; and b) at least some of the layers of part material and support material are separated from each other to form a gap between the layers of part material and layers of support material; application of heat and pressure to the part material and support material such that a portion of the part material and support material flows into and at least partially fills the gap between the part material and support material.

Abstract: Disclosed are selective deposition-based additive manufacturing systems (10) and methods for printing a 3D part (26). Layers of a powder material (22) are developed using one or more electrostatographic engines (12a-d). The layers (22) are transferred for deposition on a part build surface (88). For each of the layers (22), the part build surface (88) is pre-heated by impinging a first heat transfer liquid (74) toward the part build surface (88), for example using a solder fountain. The developed layer (22) is pressed into contact with the heated part build surface (88) to heat the developed layer (22) to a flowable state and form a new part build surface (88) which is fully consolidated. The new part build surface (88) is then rapidly cooled to remove the heat energy added during heating step before repeating the steps for the next developed layer (22).

Abstract: A laser assembly for use with an additive manufacturing system, which includes a base block configured to be moved along a scan direction axis in the additive manufacturing system, a plurality of laser emitters preferably arranged in an array of at least two rows of two or more laser emitters. At least a portion of a heat sink assembly is configured to draw heat away from the base block and/or the laser emitters. The assembly includes a controller assembly a controller assembly configured to control a movement of the base block along the first axis and to independently control at least timing and duration of energy emitted from each laser emitter of the plurality of laser emitters as the base block moves along the first axis.

Abstract: A method of selective deposition-based additive manufacturing includes conveying a layer (28) of material to previously built layers (22) of material. A determination is made as to whether at least one of the conveyed layers (28) of material and a top previously built layer (22) of material contains an unsupported portion (302). When at least one of the conveyed layer (28) of material and the top previously built layer (22) of material contains an unsupported portion, a first set of steps (306, 408, 506) are used to transfer the conveyed layer (28) of material to the top previously built layer (22) of material. When neither of the conveyed layer (28) of material and the top previously built layer (22) of material contains an unsupported portion, a second set of steps (304, 406, 504) are used to transfer the conveyed layer (28) of material to the top previously built layer (22) of material.

Abstract: A method of operating a selective deposition-based additive manufacturing system capable of building a three-dimensional (3D) part includes developing a first layer using at least one electrostatographic engine, conveying the first layer from the at least one EP engine to a transfusion assembly, determining an anticipated transfusion overlay error for the first layer, determining whether the anticipated transfusion overlay error exceeds an overlay error specification, discarding the first layer after determining that the anticipated transfusion overlay error exceeds the overlay error specification, developing a successive layer using the at least one electrostatographic engine, conveying the successive layer from the at least one electrostatographic engine to the transfusion assembly, and transfusing the successive layer on a part build surface using the transfusion assembly to build the 3D part in a layer-by-layer manner on a part build platform.

Abstract: An electrostatic-based layer-wise manufacturing system (e.g., 200; 200-1; 250; 282; 300) decouples a layer imaging process from a layer transfusion process. The layer imaging process is performed in a first batch process that is independent from the layer transfusion process that is performed in a second batch process.

Abstract: An additive manufacturing system comprising a transfer medium configured to receive the layers from a imaging engine, a heater configured to heat the layers on the transfer medium, and a layer transfusion assembly that includes a build platform, and is configured to transfuse the heated layers onto the build platform in a layer-by-layer manner to print a three-dimensional part.

Abstract: A method of producing a 3D part using a selective deposition based additive manufacturing system can include developing a first layer using at least one electrostatography engine, determining a first cross-track offset distance between an average cross-track symmetry line of the first layer and a centerline of a transfer medium, transferring the first layer to the transfer medium such that the average cross-track symmetry line of the first layer is aligned with the centerline of the transfer medium, moving a build platform relative to the transfer medium in the cross-track direction to align the first layer on a part build surface, and transfusing the first layer on the build platform using a transfusion assembly to build the part in a layer-by-layer manner. The first layer comprises at least one of a part material and a support material. The first cross-track offset distance is measured in a cross-track direction perpendicular to an in-track direction of movement of the transfer medium.

Abstract: A method for printing a three-dimensional part with an electrophotography-based additive manufacturing system having an electrophotography engine, a transfer medium, and a layer transfusion assembly includes providing a part material to the electrophotography-based additive manufacturing system, the part material compositionally comprising a charge control agent, and a thermoplastic material having a heat deflection temperature greater than about 150° C., and has a powder form. The method includes triboelectrically charging the part material to a Q/M ratio having a negative charge or a positive charge, and a magnitude ranging from about 5 micro-Coulombs/gram to about 50 micro-Coulombs/gram and developing layers of the three-dimensional part from the charged part material with the electrophotography engine.

Abstract: A method of operating a selective deposition based additive manufacturing system capable of producing a three-dimensional (3D) part includes developing a first layer using at least one electrostatography engine, transfusing the first layer on a part build surface using a transfusion assembly to build the 3D part in a layer-by-layer manner on a part build platform such that a portion of the first layer further builds a fiducial structure in a layer-by-layer manner on the part build platform, measuring a height of the fiducial structure, computing an error between the measured height of the fiducial structure and a target height, adjusting a parameter of the at least one electrostatography engine as a function of the error, developing a second layer using the at least one electrostatography engine in accordance with the adjusted parameter, and transfusing the second layer using the transfusion assembly to further build the 3D part.

Abstract: A method of printing a part in an electrophotographic additive manufacturing system includes printing a part and associated support structure in a layer by layer manner, and providing a chamber in which printing is performed. The chamber is supported by a movable platform and the chamber is positioned about a movable platen. The movable platen is supported by the movable build platform. The movable platen is movable within the chamber on the movable build platform. An electrophotography-based additive manufacturing system for printing a three-dimensional part includes a transfer medium configured to receive and transfer imaged layers of a three-dimensional part, and a support from one or more imaging engines. The system includes a heater configured to heat the imaged layers on the transfer medium to at least a fusion temperature, and a layer transfusion assembly configured to transfuse the imaged layers to the build platen or a previously printed layer.

Abstract: In a method of producing a 3D part using an electrophotography-based additive manufacturing system, a plurality of layers of a powder-based material are developed using at least one electrophotography (EP) engine. The developed layers are transferred to a transfer medium. The layers on the transfer medium are dried by heating the layers without fully fusing the powder-based material to itself using a dryer. This reduces a water content of the layers. The dried layers are heated on the transfer medium to at least a fusion temperature, at which the power-based material fuses together, using a pre-transfusion heater. The dried layers are then transfused together on a build platform using a transfusion assembly to build the part in a layer-by-layer manner.

Abstract: A part material for printing three-dimensional parts with an electrophotography-based additive manufacturing system, the part material including a composition having a grafted copolymer (including acrylonitrile units, butadiene units, aromatic units modified with polycarbonate and poly(styrene-co-maleimide)), 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.

Abstract: A method of printing a part using an additive manufacturing system includes identifying a part or parts to print and orienting a digital representation of the part(s) in a build volume. A digital representation of porous support structures for the part(s) is generated to form a digital representation of a part block of the part(s) to be printed. In the part block, a porosity of the support structure increases as a distance from an outer surface of the part increases within the print volume. The digital representation of the part block, including the part(s) and porous support structures, is sliced for printing.

Abstract: An additive manufacturing system and process for printing a three-dimensional part, which includes one or more electrophotography engines configured to develop layers of the three-dimensional part, a printing assembly configured to print the three-dimensional part from the developed layers, and a planarizer configured to conduct solvent-assisted planarizations on intermediate build surfaces of the three-dimensional part after one or more of the developed layers are printed.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.