Preventing Powder Contamination in SLS Manufacturing

Powder screening system for metal additive manufacturing equipment that improves efficiency, safety, and automation compared to existing systems. The system has modules for pumping, collecting, filtering, and screening the powder. It uses common pressure feeding to avoid high altitude issues. The filtering module vibrates the screen with ultrasonics and a motor. It has a waste tank for unqualified powder. The collecting module filters exhaust and has sensors for material and pressure levels. The system is controlled by a PLC.

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Closed-loop powder circulation system for additive manufacturing that improves efficiency and reliability compared to existing systems. The closed-loop system has features like filters, cyclones, and observation windows to prevent blocking, improve powder quality, and allow monitoring. The system uses high-pressure fan, vibrating screen, cyclone separators, overflow bucket, and feeding bucket to circulate and filter the powder. This allows continuous powder recirculation between the parts build area, recovery bucket, and feed bucket without manual intervention. The filters prevent blocking, cyclones separate fine powder, and the feed bucket has a window to monitor powder levels.

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3D printer to print implantable bone scaffolds in an aseptic environment. The printer uses a sterile cartridge of biodegradable printing material. A movable sterile receiving plate catches the printed scaffold. A cover with UV light maintains the aseptic environment inside. The cover has a filter and positive airflow to keep out contaminants. The printer also has a heater to melt the printing material for extrusion. The sterile cartridge and receiving plate can be replaced for each print to ensure sterility.

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Device and method to improve cleaning of 3D printer heads to avoid clogs and material deposition issues when changing materials. After printing a layer, the printer head flushes the nozzle by discharging a higher voltage and/or longer duration of fluid to a position outside the printed area. This higher voltage flush reduces clogging and removes powder particles from the nozzle tip.

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A container for storing powders, such as those used in additive manufacturing (AM) processes, that includes sensors to monitor and log parameters like oxygen level, humidity, temperature, pressure, weight, location, etc. The container has a pressure vessel with an outlet valve and contains powder and pressurized gas. The sensors track conditions inside the container to maintain powder quality. A control unit records and communicates the sensor data to a remote station.

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A filament feed system for 3D printers to enable sealed filament pathways to prevent moisture absorption. The system uses detachable filament supplies with connector keys that plug into printer receptacles. The keys have different shapes to fit specific receptacles. They also have guide tubes to enclose the filament path from the supply to the printer. The keys seal the receptacles to prevent air/moisture ingress.

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Depowdering additively manufactured parts containing bound metal powder by immersing the parts in a liquid-filled container, agitating the liquid to dislodge unbound powder from the parts, and filtering the liquid to recover the powder. The agitation may be mechanical vibration, gas jets, or heating to create currents that carry away the loose powder. The filtering separates the powder from the liquid for reuse or disposal.

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Cleaning liquid for post-processing additive-manufactured parts. The cleaning liquid is used to remove excess powder from 3D-printed metal parts without dissolving the binder resin used in the printing process. The cleaning liquid contains a hydrocarbon solvent with a high octanol/water partition coefficient of 4.5 or more. This solvent property allows selective removal of powder while leaving the binder intact.

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Automated fixture for removing loose powder from additively manufactured components like 3D printed parts. The fixture holds the build plate with the printed component and inverts it. Pneumatic knockers strike the inverted plate to shake the loose powder out of the component via gravity and resonance.

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Three-dimensional shaping apparatus and method for 3D printing that allows cleaning the nozzle during printing to prevent material leaks. It has a cleaning mechanism separate from the print area that can be activated mid-print to clean the nozzle. The cleaning process is triggered when pressure in the nozzle exceeds a threshold. The nozzle moves to the cleaning area, is cleaned, and then returns to printing once pressure is normal. This prevents material leaks during printing that can mar the object being printed.

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3D manufacturing technique using reactive powder beds to print objects with cross-linked regions. The method involves depositing layers of powder containing a first component. Then dispense a liquid containing a solvent and a second component that reacts with the first component when cross-linking occurs when the solvent evaporates. The process iterates to form subsequent layers until the object is complete. Unwanted particles are removed. The powder bed holds the particles and print heads dispense the reactive liquid.

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An automated dust and particle removal system for preventing contamination of downstream processing steps during manufacturing of tablets, capsules, pills, etc. The system uses oblique feed pipes and angled powder suppression plates to cause material to naturally fall into dust catchers installed in the pipe. The catchers have chambers with inlets that collect dust and residue as the material passes. This prevents contamination by automatically screening out dust and particles as the material is transferred between steps. The oblique feed pipes and suppression plates prevent dust and residue from flying or splashing into the downstream process.

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A container that can determine if the powder inside has acclimated to ambient conditions before opening compares the inside temperature/humidity to outside readings and provides an indication if the powder is ready to use. The container has sensors inside and outside and a lock that prevents flow until acclimated, preventing moisture issues from temperature changes.

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Compact vibratory feeding mechanism for cleaning powders from contamination in a compact dust removal mechanism. The mechanism uses vibration and airflow to clean powders without adding dust. It has a housing with a vibrating infeed mechanism, a venturi chamber for airflow, and a replaceable carryover deflector. The deflector aligns with the infeed structure to control powder flow into the venturi and deflects entrained powder back towards the discharge opening. The venturi removes contaminants with airflow as the powder exits. The deflector prevents carryover of cleaned powder into the discharge.

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Automatic powder feeding system for SLM additive manufacturing that ensures powder quality and operator safety by enclosing the powder handling process in a sealed loop. The system recovers, sifts, dries, and feeds the powder without exposing it to air. It has mechanisms like powder supply, recovery, feeding, sieving, and drying that are connected by pipelines and valves to form a closed loop. This allows fully automated powder handling without manual intervention or open exposure to the environment.

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Automated system for processing metal powder used in 3D printers. The system encloses the powder feeding, spreading, and recovery steps in a sealed container with integrated gas filtration. It uses cyclones and filters to clean and recirculate the inert gas used during printing. Powder is also recovered, screened, and returned to the printer. The enclosed system prevents dust escape and allows reuse of powder and gas.

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Air escape chamber for positive pressure conveying with integrated dust removal to prevent dust escaping during powder transportation. It uses a sequence of stations like bag opening, winnowing, cyclones, screw conveyors, and dust collectors. The chambers are sealed and connected by pipes with flanges. The seals prevent dust leakage. The cyclones have sealed bearings and flanges. The screw conveyors have sealed bearings and sealing flanges on the pulse tube feeding. This prevents dust escaping during conveyance. The sealed flanges on the pulse tube also allow customizing tube lengths.

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Three-dimensional additive manufacturing apparatus with a powder capture device to prevent powder from entering the vacuum pump and affecting its operation. The device has multiple flow path sections that connect the vacuum chamber to the pump. These sections have capturing sections to collide and trap powder sucked from the pump. This prevents powder from entering the pump and fouling the components. The capturing sections are spaced apart to allow continuous gas flow through the device without significant pressure drop. This avoids the issues of mesh filters blocking flow or powder clogging the pump.

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A polyolefin powder feeding system to prevent large lumps from blocking feeders and causing issues in downstream equipment like extrusion devices. The system uses a multi-stage screening, crushing, and degassing process to break down and remove lumps. The polyolefin powder enters an expansion bag filter to separate large lumps. The filtered powder goes to a vibrating screen with two outputs. Powder that passes the screen goes directly to the degassing chamber, while powder that doesn't pass goes to a pulverizer to break up lumps before degassing. This multi-stage screening and crushing process breaks down lumps before feeding downstream equipment.

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Atmosphere protection device for additive manufacturing that allows complete dust recovery and prevents gas from reclaiming with the dust. The device has a sealing box connected to an operating platform. The box has a filter with a sliding body inside. The sliding body has an exhaust channel and powder discharge channel. An exhaust fan and powder pump are in the discharge channel. The sliding body moves up and down to suck dust off the filter. The gas is exhausted separately. This allows full dust recovery without gas mixed in. The cold air inlet pumps inert gas to cool the chamber and product. The gas is then reclaimed by the pump and cooled before reintroduction. This prevents oxidation and cools the product.

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