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: A method of delivering charge to a remote target includes pressurizing a reservoir of metallic conductor initially at a temperature below its melting point. The method includes flowing the metallic conductor through an orifice to form a continuous thread with axial velocity, so that a user might direct the axial velocity of the thread to intercept the remote target. The method further includes applying a potential differential along the thread so that electrical current flows between the reservoir and the remote target.

Abstract: Disclosed are selective deposition based additive manufacturing systems (10) and methods for printing a 3D part. Layers of a powder material (22) are developed using one or more electrostatography-based engines (12). The layers (22) are transferred for deposition on a part build surface. For each of the layers (22), the part build surface is heated to a temperature within a range between a flowable temperature and a thermal oxidation threshold to form a flowable part build surface, and the developed layer (22) is pressed into contact with the flowable build surface (88) to heat the developed layers (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 cooled to remove the heat energy added during heating step before repeating the steps for the next developed layer.

Abstract: A method for 3D printing a part in a layer-wise manner includes providing a pool of polymerizable liquid in a vessel over a build window and positioning a downward-facing build platform in the pool, thereby defining a build region above the build window. The method includes selectively curing a volume of polymerizable liquid in the build region by imparting electromagnetic radiation through the build window to form a printed layer of the part adhered to the build platform and scanning at least a portion of the build window with monochromatic, polarized light along a plane of incidence. The method includes measuring a change in intensity and polarity of the light to obtain information about the printed layer. The method includes raising the build platform to a height of a next layer to be printed and modifying the electromagnetic energy imparted into the next layer based upon the obtained information to print a next layer.

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: 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 method for 3D printing a part in a layer-wise manner includes providing a pool of polymerizable liquid in a vessel over a build window and positioning a downward-facing build platform in the pool, thereby defining a build region above the build window. The method includes selectively curing a volume of polymerizable liquid in the build region by imparting electromagnetic radiation through the build window to form a printed layer of the part adhered to the build platform and scanning at least a portion of the build window with monochromatic, polarized light along a plane of incidence. The method includes measuring a change in intensity and polarity of the light to obtain information about the printed layer. The method includes raising the build platform to a height of a next layer to be printed and modifying the electromagnetic energy imparted into the next layer based upon the obtained information to print a next layer.

Abstract: Methods and systems for additive manufacturing are disclosed, the methods and systems comprising reducing the amount of support material used, by one or more methods, including inclusion of part material voxels and air voxels within the support regions, using a lattice of part material within support regions, printing one or more skin layers and boundary layers to support the part geometry and surface, and printing support layers in a drafted manner to reduce support material.

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 cooling assembly, and method, for an article being printed using a selective toner electrophotographic printing system is disclosed. The assembly includes a surface for delivering and returning cooling gas, the surface containing first plurality of elongate openings in communication with a cooling gas supply; and a second plurality elongate openings in communication with a cooling gas return; wherein the first plurality of elongate openings and second plurality of elongate openings are substantially parallel to one another and alternate with one another.

Abstract: Disclosed are selective layer deposition based additive manufacturing systems and methods for printing a 3D part. Layers of a powder material are developed using one or more electrostatography-based engines. The layers are transferred for deposition on a part build surface. One or more lasers are used to heat a region of the part build surface and a developed layer near the nip roller entrance. The developed layer is then pressed into the part build surface.

Abstract: In a method of printing a 3D part in accordance with a selective deposition additive manufacturing process a first image portion of a flowable material is developed using a first electrophotographic engine. A second image portion of a resilient material is developed using a second electrophotographic engine. The first image portion is registered with respect to the second image portion to form a combined image layer comprising the first and second image portions on a transfer medium. The combined image layer is transfused from the transfer medium to a part build surface of a 3D part. The viscosity (Vr) of the resilient material is greater than or equal to three times the viscosity (Vf) of the flowable material, and/or the storage modulus (Er) of the resilient material is greater than or equal to three times the storage modulus (Ef) of the flowable material.

Abstract: A print assembly 18 for use in an additive manufacturing system 10 to print three-dimensional parts 12, which includes a coarse positioner 40, a fine positioner 42, and a liquefier assembly 20, where a portion of the liquefier assembly 20 is operably mounted to the fine positioner 42 such that the fine positioner 42 is configured to move the portion of the liquefier assembly 20 relative to the coarse positioner 40.

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: A print assembly for use in an additive manufacturing system to print three-dimensional parts, which includes a coarse positioner, a fine positioner, and a liquefier assembly, where a portion of the liquefier assembly is operably mounted to the fine positioner such that the fine positioner is configured to move the portion of the liquefier assembly relative to the coarse positioner.

Abstract: A method for making a three-dimensional (3D) part with an electrostatographic based additive manufacturing system includes establishing first and second control parameter profiles, establishing a transfusion sequence, and transfusing n+m layers on a bonding region of previously accumulated layers of the 3D part according to the transfusion sequence. The first and second control parameter profiles each include a different combination of temperature and pressure parameters usable to transfuse a single layer of the 3D part. The transfusion sequence specifies the use of each of the first and second control parameter profiles in a specified order. A total thickness of the n+m layers is less than a thermal diffusion depth. The transfusion step includes transfusing n layers according to the first control parameter profile, and, after transfusing then layers, transfusing m layers according to the second control parameter profile.

Abstract: A method of delivering an electric charge to a remote target with a CEW includes using one or more sensors in communication with the CEW to determine a threat level of a situation and contacting the target with at least one electrode wire discharged from the CEW. The method further includes applying an electric charge along the at least one electrode wire so that electrical charge flows between the CEW and the remote target based upon the determined threat level of the situation.

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: A selective deposition-based additive manufacturing system capable of building a three-dimensional (3D) part utilizing a semi-crystalline polymeric material includes at least one electrostatographic engine configured to develop one or more layers of particles of semi-crystalline polymeric material corresponding to one or more slices of a 3D model of a 3D part. The system includes a transfer medium configured to receive the one or more layers of particles of the semi-crystalline polymeric material on a front side from the at least one electrostatographic engine and to move the one or more layers away from the electrostatographic engine and a platen configured to carry the 3D part or support being printed. The system includes a gantry coupled to the platen and configured to move the platen into registration with the one or more layers, and a heater configured to heat a top surface of the 3D part being printed to a transfuse temperature.

Abstract: A method for 3D printing a part in a layer-wise manner includes providing a pool of polymerizable liquid in a vessel over a build window and positioning a downward-facing build platform in the pool, thereby defining a build region above the build window. The method includes selectively curing a volume of polymerizable liquid in the build region by imparting electromagnetic radiation through the build window to form a printed layer of the part adhered to the build platform and scanning at least a portion of the build window with monochromatic, polarized light along a plane of incidence. The method includes measuring a change in intensity and polarity of the light to obtain information about the printed layer. The method includes raising the build platform to a height of a next layer to be printed and modifying the electromagnetic energy imparted into the next layer based upon the obtained information to print a next layer.