Techniques for 3D Printing Large Objects

Solid freeform fabrication (SFF) method and apparatus for 3D printing high-resolution parts with improved material properties. The method involves delivering a layer of build material, consisting of powder and binder, to a build surface. The binder density is adjusted by removing some binder or increasing it through evaporation or fluid flow. This allows changing the powder loading and part density without affecting resolution. The method also uses techniques like micropixelation, image shifting, and adhesive layer deposition to further improve resolution and part quality.

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3D printing method and 3D printer that enable efficient use of the build chamber volume by adjusting the build platform height. The method involves starting the printing process with the build platform at a lower position, then raising it as needed during the print to prevent the finished layers from colliding with the nozzle. This allows taller parts to be printed without requiring a taller build chamber. The printer has a height-adjustable build platform accommodated within the side wall structure of the build box. The platform can be raised as the print progresses to prevent collision between the completed layers and the nozzle. This enables printing of taller parts without needing a taller build chamber.

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Method of producing objects with complex shapes using 3D printing followed by post-processing to further deform and shape the 3D printed part. The method involves creating an initial 3D printed part with certain features, then using techniques like heating, masking, deep drawing, or forming to deform and shape the part into the final object shape. This allows more complex shapes with better mechanical properties compared to just 3D printing the final shape.

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A device for lithography-based additive manufacturing of three-dimensional structures on curved surfaces by rolling contact between the surface and a layer coated with photopolymer resin. The device has a light engine projecting patterned light onto the layer as it rolls. The layer feeding rate and light pulse rate synchronize to avoid motion blur. The rolling contact enables 3D printing on curved surfaces with a larger area than the light engine exposure field. It's useful for manufacturing cylindrical objects like bottles or tubes.

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A building unit for large-format additive manufacturing with an inert gas system to allow high-quality prints at scale. The build unit has an energy beam system and an inertization system with supply and return manifolds. The supply manifold includes a downward flow manifold and a crossflow manifold to provide process gas flow through the irradiation chamber. The return manifold evacuates the gas. This prevents contaminants from the powder bed from contacting the energy beam components, allowing clean prints.

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Wall-thickness additive manufacturing device for micro cast-rolling additive manufacturing of large-scale special-shaped pipes, such as those used in nuclear power plants. The device uses a crossed slide assembly and laser cladding assembly on a vertical wall to additively manufacture large irregular steel pipes. It enables near-net-shape manufacturing of complex-shaped pipes with variable wall thicknesses in a single step using laser cladding.

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A method to create large-scale biological tissue containing regulated vascular structures for use in 3D cell culture and tissue engineering applications. The tissue is formed by printing a coaxial scaffold structure containing a thermosensitive material. After curing the outer scaffold material, the inner thermosensitive material is melted away to leave a hollow duct. A cell-laden hydrogel is then poured into the duct to create the tissue. The coaxial printing allows adjustable porosity of the duct walls. The thermosensitive material provides temporary support during hydrogel filling.

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A method of secure and releasable attachment of a build sheet to a print bed in large-scale additive manufacturing without the need for adhesive. The method uses vacuum suction to hold the build sheet in place on the print bed. The print bed has a surface with a plurality of perforations. A vacuum source is connected to the perforations to apply suction through the holes. This pulls the build sheet down and holds it securely to the bed during printing. The vacuum can be released to remove the build sheet after printing easily.

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Additive manufacturing method for 3D printing objects with overhangs using fewer supports compared to conventional methods. The key idea is to construct the overhangs using solidification paths that start and end on adjacent supports, rather than hanging in mid-air. This allows reducing the number of supports needed for overhangs. The method involves defining hardening paths for each layer that start and end on adjacent supports for overhang sections. This ensures the solidification is fully supported and prevents sagging. The supports are arranged perpendicular to the print direction.

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Efficient encoding of 3D printing build data for additive manufacturing that reduces memory and processing requirements compared to voxel-based representation. The method involves processing the 3D model to extract boundary intersection points for rays instead of voxelizing the entire model. This pre-computed ray-based build data is used during printing to determine material deposition at each layer based on the ray height. It enables faster and more memory-efficient printing of complex objects with many material transitions.

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Additive manufacturing of large parts using a linear laser beam increases efficiency and reduces costs compared to point laser beams. The method involves using a laser-generating unit that projects a linear light spot onto the material and drives the laser, platform, or material feed to move during manufacturing.

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Additive manufacturing method to produce large components using 3D printers that can't fit entirely in the printer's build area. The method involves building an enclosure around the partially printed component as it grows. This allows the component to extend beyond the printer's build volume without exposing the unfinished part to the environment. The enclosure is printed layer by layer around the component in a horizontal direction to completely enclose it. This prevents feedstock and gases from escaping and contaminating the unfinished part. The enclosed component can then be further printed to completion using the 3D printer.

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Additively manufacturing customized minimum surface structures for 3D printed parts to optimize performance and reduce stress by generating a digital minimal surface model based on local physical parameter requirements. The method involves creating a density field representing required parameter values, generating an adaptive Voronoi tessellation from it, and extracting skeletons to create a digital minimal surface model. This allows designing minimum surfaces that adapt to specific boundary conditions and parameters.

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Printing 3D objects with improved quality, reduced defects, and increased design flexibility compared to conventional 3D printing methods. The technique involves using two energy sources, like lasers, to print overhangs with curved surfaces. One energy source forms the overhang, and the other reshapes it by impinging the overhang, hard material, or both. This prevents warping and deformation during printing. The technique also involves monitoring melt pool dynamics, comparing real-time signals to targets, and adjusting print parameters accordingly. It allows printing complex 3D objects with high accuracy, low surface roughness, and low porosity overhangs.

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3D printing composite parts with hybrid structures using a specialized print head on a robot arm. The method involves 2D printing the core of the part first, then 3D printing a directional fiber-reinforced layer on the exterior. The print head has multiple connections and power inputs for mounting on the robot arm. The dual-step process allows creating composite parts with high stiffness in specific directions while minimizing weight. It avoids the need for molds and enables complex shapes with customized fiber orientations.

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Additively manufacturing thermoplastic composite parts with reinforced interlaminar strength. The method involves using a 3D printing machine to build the part layer by layer, then inserting Z-pins through the layers to reinforce the part in the Z-direction. The pins are inserted using thermal, mechanical, ultrasonic, or chemical energy to penetrate the hardened material. This provides reinforcement directly in the part instead of relying solely on adhesive bonding between layers. The pins are inserted during or after printing, and can be staggered and varying in length.

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Additive manufacturing of 3D objects using removable sacrificial structures to enable easy removal of printed objects. The process involves overlaying objects with a flexible sacrificial material, followed by an intermediate layer of support material. This allows the objects to be separated from the sacrificial structure by pushing them out. The flexible sacrificial material can have a predetermined combination of modeling and support materials. Multiple objects can also be printed within a shared sacrificial structure with destructible skirt connections between them.

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3D printing method and device for producing objects with improved strength and reduced support requirements compared to traditional layer-by-layer printing. The method involves creating a digital 3D model of the object and separating it into flat and curved layers. The curved layers are printed on a vertical receiving surface, while the flat layers are printed on a horizontal surface. This allows the object to be built vertically without interlayer binding issues. The vertical surface is rotated between curved and flat layer printing to create the object. The device has a print head, motors for motion, and a rotating receiving surface. The method avoids the need for support structures and allows printing objects with complex shapes.

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A 3D printing system with an extruder head having multiple nozzles and actuators to improve the strength of 3D printed objects in the Z direction. The system alternates the deposition direction of successive layers to create interlocking connections between layers. An actuator moves the extruder head in XY planes parallel to the build platform, rotates it around an axis perpendicular to XY, and varies the distance between head and platform. Modified instructions tell the head to deposit connecting swaths in adjacent layers during object formation. This interlocking structure improves Z-axis adhesion compared to traditional single-extrusion printing.

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Large-format 3D printing uses separated components with tracking to increase print size beyond the printer's build volume. The method involves using a 3D printer made of movable components, each with a tracker. The trackers provide local coordinate systems, which a processing unit combines into a global coordinate system. Printing instructions are generated based on the global coordinates to print larger objects accurately. The tracking system also allows scanning a large object in sections and combining the scans.

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