# US 11,305,349 B2 · Method and apparatus for forming layers of particles for use in additive manufacturing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,305,349 B2 - Document ID: US11305349B2 - Status: Granted - Kind: B2 - Application number: 16/084,407 - Filed: 2017-03-13 - Published: 2019-03-21 - Granted: 2022-04-19 - Earliest claimed: 2016-03-14 - Assignees: Nanogrande - Applicants: Nanogrande - Inventors: Juan Schneider - Web page: https://patentgrep.com/patent/US11305349B2 ## CPC - B29C 64/165: using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber - B05C 19/04: the particulate material being projected, poured or allowed to flow onto the surface of the work (B05C19/02 takes precedence; involving spraying or electrostatic projection B05B ){(B05C19/005 takes precedence)} - B22F 1/0545: Dispersions or suspensions of nanosized particles - B22F 1/10: Metallic powder containing lubricating or binding agents; Metallic powder containing organic material - B22F 1/14: Treatment of metallic powder (mixing with lubricating or binding agents or with organic material B22F1/10) - B22F 7/02: of composite layers {(B22F7/002 takes precedence)} - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B29C 64/205: Means for applying layers - B29C 64/314: Preparation - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B33Y 40/10: Pre-treatment - B33Y 40/20: Post-treatment, e.g. curing, coating or polishing - B05D 1/20: substances to be applied floating on a fluid - B22F 10/28: Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] - B22F 10/68: Cleaning or washing - B22F 10/73: of powder - B22F 12/49: Scanners - B22F 2203/00: Controlling - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - Y02P 10/25: Process efficiency - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B05C: APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (spraying apparatus, atomising apparatus, nozzles B05B; plant for applying liquids or other fluent materials to objects by electrostatic spraying B05B5/08) - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method and an apparatus for forming a particle layer are provided. The layering method includes injecting particles in an injection zone defined at a gas-liquid interface between a carrier liquid and an ambient gas, and controlling a flow of the carrier liquid along the gas-liquid interface to carry the particles downstream along a particle flow path from the injection zone to a layer formation zone. The method also includes accumulating the particles in the layer formation zone to gradually form the particle layer on the gas-liquid interface, and withdrawing the particle layer from the layer formation zone. The particle layer formed by the layering method and apparatus can be used to fabricate a three-dimensional object by additive manufacturing. ## Claims ### Claim 1 A method for forming a particle layer, the method comprising the steps of: providing an apparatus for forming a particle layer, the apparatus comprising: a vessel for receiving a carrier liquid; an injection assembly; a flow control assembly disposed in the vessel such that, when the carrier liquid is present in the vessel, the flow control assembly is submerged at least partly in the carrier liquid, wherein the flow control assembly comprises at least one flow control device and wherein the at least one flow control device comprises at least one belt conveyor; and a transfer assembly: injecting, using the injection assembly, particles in an injection zone defined at a gas-liquid interface between the carrier liquid received in the vessel and an ambient gas; controlling, using the flow control assembly, a flow of an upper portion of the carrier liquid along the gas-liquid interface to carry the particles downstream along a particle flow path from the injection zone to a layer formation zone, wherein the upper portion of the carrier liquid extends from the gas-liquid interface down to an operating depth below the gas-liquid interface, and wherein each flow control device is located at the operating depth and operated at an operating speed parallel to the gas-liquid interface; accumulating the particles in the layer formation zone to gradually form the particle layer on the gas-liquid interface; and withdrawing, using the transfer assembly, the particle layer from the layer formation zone. ### Claim 2 (depends on 1) The method of claim 1, wherein the injecting step comprises injecting the particles in the injection zone at a single injection point, at a plurality of spaced-apart injection points in the injection zone, or along an injection line. ### Claim 3 (depends on 1) The method of claim 1, wherein the controlling step comprises controlling the flow of the carrier liquid substantially without gravity flow. ### Claim 4 (depends on 1) The method of claim 1, wherein the controlling step of comprises selecting at least one of the operating depth and the operating speed based on a viscosity of the carrier liquid. ### Claim 5 (depends on 1) The method of claim 1, wherein the accumulating step comprises a step of restricting the flow of the carrier liquid in the layer formation zone. ### Claim 6 (depends on 1) The method of claim 1, wherein the withdrawing step comprises a step of removing the particle layer gradually and concurrently with the accumulating step or only once the particle layer or a portion thereof is fully formed. ### Claim 7 (depends on 1) The method of claim 1, wherein the withdrawing step comprises a step of controlling a lateral pressure in the particle layer. ### Claim 8 (depends on 7) The method of claim 7, wherein the step of controlling the lateral pressure in the particle layer comprises adjusting a ratio between the flow of the carrier liquid along the gas-liquid interface and a withdrawal rate of the particle layer from the layer formation zone. ### Claim 9 (depends on 1) The method of claim 1, wherein the particles are between about 1 nanometer and about 100 micrometers in diameter. ### Claim 10 (depends on 1) An additive manufacturing method for fabricating a three-dimensional (3D) object, comprising the steps of: forming a particle layer using the method of claim 1; transferring the particle layer withdrawn from the layer formation zone to a working zone; joining a predetermined portion of the transferred layer together in a selective manner to form, in the working zone, one of a plurality of discrete cross-sectional regions that cumulatively form the 3D object; and repeating the forming, transferring and joining steps a plurality of times to stack the plurality of discrete cross-sectional regions one on top of the other, and build up, layer by layer, the 3D object. ### Claim 11 An apparatus for forming a particle layer, the apparatus comprising: a vessel for receiving a carrier liquid such that, when the carrier liquid is present in the vessel, the carrier liquid defines a gas-liquid interface with an ambient gas; an injection assembly configured to inject particles in an injection zone defined at the gas-liquid interface; a flow control assembly disposed in the vessel such that, when the carrier liquid is present in the vessel, the flow control assembly is submerged at least partly in the carrier liquid and configured to control a flow of the carrier liquid along the gas-liquid interface, the flow of the carrier liquid carrying the particles downstream along a particle flow path from the injection zone to a layer formation zone where the particles accumulate and gradually form the particle layer on the gas-liquid interface; and a transfer assembly configured to withdraw the formed particle layer from the layer formation zone wherein the flow control assembly is configured to control a flow of an up per portion of the carrier liquid extending from the gas-liquid interface down to an operating depth below the gas-liquid interface, wherein the flow control assembly comprises at least one flow control device, each flow control device being located at the operating depth and being operated at an operating speed parallel to the gas-liquid interface, and wherein the at least one flow control device comprises at least one belt conveyor. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the injection assembly comprises a single injector. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein the injection assembly comprises a plurality of injectors. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein the flow control assembly is configured to control the flow of the carrier liquid along the gas-liquid interface substantially without gravity flow. ### Claim 15 (depends on 11) The apparatus of claim 11, wherein the at least one flow control device consists of a plurality of flow control devices. ### Claim 16 (depends on 11) The apparatus of claim 11, wherein the flow control assembly comprises a fixed substrate submerged in the carrier liquid and a pump submerged at least partly in the carrier liquid upstream of the injection zone. ### Claim 17 (depends on 11) The apparatus of claim 11, wherein the transfer assembly comprises a barrier against which the particles accumulate particles and gradually form the particle layer on the gas-liquid interface. ### Claim 18 (depends on 11) The apparatus of claim 11, wherein the transfer assembly comprises a rotating cylinder having a peripheral surface, the rotating cylinder being located at a downstream end of the layer formation zone and configured to convey the particle layer out of the layer formation zone along the peripheral surface thereof. ### Claim 19 (depends on 11) The apparatus of claim 11, wherein the transfer assembly comprises a belt conveyor including a conveyor belt, the belt conveyor being located at a downstream end of the layer formation zone and configured to convey the particle layer out of the layer formation zone along the conveyor belt. ### Claim 20 (depends on 11) The apparatus of claim 11, further comprising a barrier located at least partly upstream of the injection zone and configured to promote the flow of the particles downstream along the particle flow path. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the barrier is movable and configured to move downstream along the particle flow path to push the particle layer toward and onto the transfer assembly for withdrawal of the same. ### Claim 22 (depends on 11) The apparatus of claim 11, wherein the transfer assembly is configured to form a capillary bridge between the transfer assembly and a working zone to deposit the particle layer onto the working zone. ### Claim 23 A method for forming a particle layer, the method comprising the steps of: providing an apparatus for forming a particle layer, the apparatus comprising: a vessel for receiving a carrier liquid; an injection assembly; a flow control assembly disposed in the vessel such that, when the carrier liquid is present in the vessel, the flow control assembly is submerged at least partly in the carrier liquid; a transfer assembly; and a movable barrier; injecting, using the injection assembly, particles in an injection zone defined at a gas-liquid interface between the carrier liquid received in the vessel and an ambient gas; controlling, using the flow control assembly, a flow of the carrier liquid along the gas-liquid interface to carry the particles downstream along a particle flow path from the injection zone to a layer formation zone; accumulating the particles in the layer formation zone to gradually form the particle layer on the gas-liquid interface; moving, from a location at least partly upstream of the injection zone, the movable barrier downstream along the particle flow path to promote the flow of the particles downstream along the particle flow path and push the particle layer toward and onto the transfer assembly for withdrawal of the same; and withdrawing, using the transfer assembly, the particle layer from the layer formation zone. ### Claim 24 (depends on 23) An additive manufacturing method for fabricating a three-dimensional (3D) object, comprising the steps of: forming a particle layer using the method of claim 23; transferring the particle layer withdrawn from the layer formation zone to a working zone; joining a predetermined portion of the transferred layer together in a selective manner to form, in the working zone, one of a plurality of discrete cross-sectional regions that cumulatively form the 3D object; and repeating the forming, transferring and joining steps a plurality of times to stack the plurality of discrete cross-sectional regions one on top of the other, and build up, layer by layer, the 3D object. ### Claim 25 An apparatus for forming a particle layer, the apparatus comprising: a vessel for receiving a carrier liquid such that, when the carrier liquid is present in the vessel, the carrier liquid defines a gas-liquid interface with an ambient gas; an injection assembly configured to inject particles in an injection zone defined at the gas-liquid interface; a flow control assembly disposed in the vessel such that, when the carrier liquid is present in the vessel, the flow control assembly is submerged at least partly in the carrier liquid and configured to control a flow of the carrier liquid along the gas-liquid interface, the flow of the carrier liquid carrying the particles downstream along a particle flow path from the injection zone to a layer formation zone where the particles accumulate and gradually form the particle layer on the gas-liquid interface; a transfer assembly configured to withdraw the formed particle layer from the layer formation zone; and a barrier located at least partly upstream of the injection zone and configured to promote the flow of the particles downstream along the particle flow path, wherein the barrier is movable and configured to move downstream along the particle flow path to push the particle layer toward and onto the transfer assembly for withdrawal of the same.