Achieving Uniform Powder Distribution in Selective Laser Sintering (SLS)

A loading system for 3D printers that reduces mounding and increases the uniformity of powder layers. The system has a loading chamber positioned over the supply container. Powder is dispensed into the chamber and compacted to increase uniformity. The chamber floor is then lowered into the supply container, transferring the compacted powder. This loading process helps distribute the powder more evenly throughout the container than directly filling it.

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A process to make polyolefin powders for 3D printing that have a small size, narrow size distribution, spherical shape, high density, and good flowability. The process starts with the aqueous dispersion of polyolefin particles containing a high-melting ethylene-based polymer, a polyolefin wax, and an acrylic dispersant. The dispersion is diluted, the solid particles collected, washed to remove excess dispersant, and dried to form the powder.

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Additive manufacturing using a powder bed with powder distributed on a build surface includes a nozzle configured to direct and control the flow of gas over the powder bed. The nozzle may include a peripheral duct wall defining a channel with an inlet and an outlet. The channel directs the flow. The duct wall may diverge from the inlet to the outlet of the duct wall to slow the velocity of the gas flow. A number of vanes are distributed across the channel and may be configured as symmetric airfoils to reduce turbulence of the flow. A number of guides extend between the vanes. Each guide is disposed at an angle tuned to direct the gas over the powder bed without blowing the deposited powder off the build surface.

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Apparatus and method for preconditioning powder before calendering in 3D printing. The powder is dispensed on a substrate, and then a conditioning agent is applied to increase powder cohesiveness before compacting. This ensures uniform compaction and prevents powder from sticking and splitting during calendering. The conditioning agent can be steam to avoid damage.

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A 3D printer that removes powder build-up from the powder dispensing system to maintain uniform layer thickness. The printer has a vibrating powder coater that scans over the build plate and dispenses powder for each layer. After a set number of layers, the coater is moved to an overflow chamber and vibrated to shake off the accumulated powder. This prevents excess powder from affecting subsequent layers. The printer uses a controller to automate the powder removal process.

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Improved recoating and dust collection systems for powder-based 3D printers that enable more efficient and controlled 3D printing using fine powders. The recoating system uses ultrasonic vibrations applied to a perforated screen to dispense the powder in uniform layers. This prevents the pluming of the fine powder particles during dispensing. The dust collection system captures any powder particles that become airborne during printing to prevent contamination and loss of material. The combination of the recoater and dust collection systems allows fine powders to be used with powder-based 3D printers without issues like pluming and excess powder.

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Powder delivery mechanism for 3D printers that uses a rotating doser with a recess to move a consistent amount of powder from a hopper to a trough for each layer.

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An additive manufacturing method that uses impulses to settle and fluidize powder in a build chamber to improve part consistency and efficiency. The method involves delivering impulses to the build chamber to settle fresh and loose powder, then selectively jetting the binder onto the settled powder. This allows for the consistent part formation and gross depowdering.

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A method for forming three-dimensional articles by fusing powder layers layer-by-layer using an electron beam. The method involves distributing a layer of powder on a work table, applying an electron beam to fuse the powder in selected locations corresponding to cross sections of the 3D article, and detecting x-rays or secondary electrons emitted from the sensor attached to the powder distributor. The sensor is a metal plate with an opening facing the electron beam. The detection allows calibrating/verifying the electron beam size and shape compared to the desired cross-section of the 3D article.

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Additive manufacturing system that uses a powder distribution system to build objects on a stage. The system has a powder buffer that stores powder and distributes it over the stage using a roller. The buffer has two reservoirs that dispense powder through holes in the roller. The roller flattens the powder as it distributes it to create a uniform layer. The system can control the powder flow rate and layer thickness by adjusting the roller speed and hole size.

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3D printing method and apparatus that enables high speed printing of objects by depositing multiple layers of powder simultaneously onto the operative surface. The powder layers are deposited in a staggered manner such that the topmost surface of each layer is exposed and not covered by an overlying layer. The energy source emits energy beams onto the exposed surfaces of the powder layers to melt and form part of the 3D object.

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Using thicker powder layers in additive manufacturing to accelerate the construction rate of complex components. The thicker layers are created by depositing multiple thin layers of powder and then melting them together. This allows for faster deposition of larger amounts of powder without sacrificing accuracy.

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A device and method for manufacturing three-dimensional objects using laser sintering or 3D printing. The device has an application device that applies layers of powder to the building surface. The application device has a fluidization mechanism to improve powder flowability and homogeneity. The fluidization mechanism uses a gas like nitrogen to fluidize the powder. The gas is introduced into the application device and escapes through openings in the walls. This improves powder flow and homogeneity. The device also has a heating mechanism to preheat the powder before application.

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A three-dimensional additive manufacturing device that can construct a shaped object by using a plurality of types of metal powder. The device has a stage for spreading the metal powder, a powder supply unit to hold and dispense the powder, and an electron beam irradiation system to melt the powder. The irradiation system has a beam emitting portion that scans the beam across the stage. The device stores beam control data for each type of metal powder that specifies the irradiation position and intensity. The control system reads the data and directs the beam to the correct position for each powder type.

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Method for improving powder distribution in additive manufacturing to increase density and improve material properties. The method involves applying a first layer of powder with a first particle size distribution, then removing a portion of the layer to increase density. A second layer of powder with a different particle size distribution is then applied on top. This process is repeated to build up the 3D object layer by layer. The first layer has a larger particle size distribution than the second layer, so removing a portion of the first layer increases density without affecting the second layer.

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