# US 12,214,421 B2 · Three-dimensional (3D) printing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,421 B2 - Document ID: US12214421B2 - Status: Granted - Kind: B2 - Application number: 17/838,050 - Filed: 2022-06-10 - Published: 2022-09-22 - Granted: 2025-02-04 - Earliest claimed: 2022-06-10 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Vladek Kasperchik; Mohammed S. Shaarawi; Michael G. Monroe; David Michael Ingle - Web page: https://patentgrep.com/patent/US12214421B2 ## CPC - B22F 10/14: by jetting of binder onto a bed of metal powder - B22F 1/05: Metallic powder characterised by the size or surface area of the particles - B22F 1/10: Metallic powder containing lubricating or binding agents; Metallic powder containing organic material - B22F 3/1021: {Removal of binder or filler (removal of binder from ceramics C04B35/638)} - B22F 10/10: Formation of a green body - B22F 10/16: by embedding the binder within the powder bed - B22F 10/32: of the atmosphere, e.g. composition or pressure in a building chamber - B22F 10/34: of powder characteristics, e.g. density, oxidation or flowability - B22F 10/50: Treatment of workpieces or articles during build-up, e.g. treatments applied to fused layers during build-up - B22F 12/10: Auxiliary heating means - 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 - B29C 64/209: Heads; Nozzles - B29C 64/295: Heating elements - B29C 64/371: using an environment other than air, e.g. inert gas - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 40/20: Post-treatment, e.g. curing, coating or polishing - B33Y 70/00: Materials specially adapted for additive manufacturing - B33Y 70/10: Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials - C08L 13/02: Latex - B22F 1/103: containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent - B22F 3/10: Sintering only - B22F 3/1007: {Atmosphere (B22F3/1021 takes precedence)} - B22F 5/08: of toothed articles, e.g. gear wheels; of cam discs - B22F 12/53: Nozzles - B22F 12/63: Rollers - B22F 2201/013: Hydrogen - B22F 2201/02: Nitrogen - B22F 2201/04: CO or CO2 - B22F 2201/20: Use of vacuum - B22F 2304/10: Micron size particles, i.e. above 1 micrometer up to 500 micrometer - B22F 2998/10: Processes characterised by the sequence of their steps - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - C08K 5/053: Polyhydroxylic alcohols - Y02P 10/25: Process efficiency - 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 - 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) - 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 - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract In a three-dimensional (3D) printing method example, a metallic build material is applied. A binder fluid is selectively applied on at least a portion of the metallic build material. The binder fluid includes a liquid vehicle and polymer particles dispersed in the liquid vehicle. The application of the metallic build material and the selective application of the binder fluid are repeated to create a patterned green part. The patterned green part is heated to at about a melting point of the polymer particles to activate the binder fluid and create a cured green part. The cured green part is heated to a thermal decomposition temperature of the polymer particles to create an at least substantially polymer-free gray part. The at least substantially polymer-free gray part is heated to a sintering temperature to form a metallic part. ## Claims ### Claim 1 A three-dimensional (3D) printing system, comprising: a container containing a supply of metallic build material; a build material distributor; an inkjet applicator containing a supply of a binder fluid and to selectively apply the binder fluid, the binder fluid including a liquid vehicle and polymer particles dispersed in the liquid vehicle, the polymer particles including a hydrophobic component and a hydrophilic component having a glass transition temperature (Tg) that is higher than the hydrophobic component, and each of the polymer particles containing one of: (i) polymerized hydrophobic monomers that form the hydrophobic component, polymerized hydrophilic monomers that form the hydrophilic component, and the hydrophilic component attached to a surface of the hydrophobic component; (ii) a ratio of polymerized hydrophobic monomers to polymerized hydrophilic monomers ranging from 5:95 to 30:70; (iii) a higher concentration of polymerized hydrophilic monomers at or near a surface of the hydrophobic component; and (iv) a core-shell structure with copolymerized hydrophobic and hydrophilic monomers at a core of the core-shell structure and a higher concentration of copolymerized hydrophilic monomers at a shell of the core-shell structure; at least one heat source; a controller; and a non-transitory computer readable medium having stored thereon computer executable instructions to cause the controller to: utilize the build material distributor and the inkjet applicator to iteratively form multiple layers of the metallic build material which are applied by the build material distributor and have received the binder fluid, thereby creating a patterned green part; and utilize the at least one heat source to: heat the patterned green part to about a melting point of the polymer particles for a curing time period ranging from about 1 minute to about 360 minutes, thereby activating the binder fluid and creating a cured green part; heat the cured green part to a thermal decomposition temperature of the polymer particles for a thermal decomposition time period ranging from about 10 minutes to about 72 hours, thereby creating an at least substantially polymer-free gray part; and heat the at least substantially polymer-free gray part to a sintering temperature for a sintering time period ranging from about 20 minutes to about 15 hours to form a metallic part. ### Claim 2 (depends on 1) The system as defined in claim 1 wherein: the polymer particles have a glass transition temperature (Tg) ranging from about 25° C. to about 125° C.; the melting point ranges from about 125° C. to about 200° C.; the thermal decomposition temperature ranges from about 250° C. to about 600° C.; and the sintering temperature ranges from about 850° C. to about 1400° C. ### Claim 3 (depends on 1) The system as defined in claim 1 wherein the heating of the cured green part to the thermal decomposition temperature and the heating of the at least substantially polymer-free gray part to the sintering temperature are accomplished in an environment containing an inert gas, nitrogen gas, a reducing gas, or a combination thereof. ### Claim 4 (depends on 3) The system as defined in claim 3 wherein the environment further contains carbon. ### Claim 5 (depends on 1) The system as defined in claim 1 wherein the binder fluid further includes a coalescing solvent selected from the group consisting of 2-pyrrolidinone, 1-(2-hydroxyethyl)-2-pyrrolidone, tripropylene glycol mono methyl ether, dipropylene glycol mono methyl ether, dipropylene glycol mono propyl ether, tripropylene glycol mono n-butyl ether, propylene glycol phenyl ether, dipropylene glycol methyl ether acetate, diethylene glycol mono butyl ether, diethylene glycol mono hexyl ether, ethylene glycol phenyl ether, diethylene glycol mono n-butyl ether acetate, ethylene glycol mono n-butyl ether acetate, 2-methyl-1,3-propanediol, and a combination thereof. ### Claim 6 (depends on 5) The system as defined in claim 5 wherein: the polymer particles are present in the binder fluid in an amount ranging from about 2 wt % to about 30 wt %; and the coalescing solvent is present in the binder fluid in an amount ranging from about 0.1 wt % to about 50 wt %. ### Claim 7 (depends on 1) The system as defined in claim 1 wherein: the hydrophobic monomers of the polymerized hydrophobic monomers are selected from the group consisting of C4 to C8 alkyl acrylate monomers, C4 to C8 alkyl methacrylate monomers, styrene monomers, substituted methyl styrene monomers, vinyl monomers, vinyl ester monomers, and combinations thereof; and the hydrophilic monomers of the polymerized hydrophilic monomers are selected from the group consisting of acidic monomers, unsubstituted amide monomers, alcoholic acrylate monomers, alcoholic methacrylate monomers, C1 to C2 alkyl acrylate monomers, C1 to C2 alkyl methacrylate monomers, and combinations thereof. ### Claim 8 (depends on 1) The system as defined in claim 1 wherein: the metallic build material is a powder with an average particle size ranging from about 10 μm to about 150 μm; the metallic build material is to sinter into a continuous body to form the metallic part when heated to the sintering temperature; and the sintering temperature is below a melting point, a solidus temperature, a eutectic temperature, or a peritectic temperature of the metallic build material. ### Claim 9 (depends on 1) The system as defined in claim 1 wherein each of the multiple layers of the metallic build material has a thickness ranging from about 30 μm to about 300 μm. ### Claim 10 A three-dimensional (3D) printing method, the method utilizing a controller including a non-transitory computer readable medium having stored thereon computer executable instructions to cause at least one step of the method, the method comprising: using a build material distributor, applying a metallic build material from a container containing a supply of the metallic build material; using an inkjet applicator, selectively applying a binder fluid on at least a portion of the metallic build material, the binder fluid including a liquid vehicle and polymer particles dispersed in the liquid vehicle, the polymer particles including a hydrophobic component and a hydrophilic component having a glass transition temperature (Tg) that is higher than the hydrophobic component, and each of the polymer particles containing one of: (i) polymerized hydrophobic monomers that form the hydrophobic component, polymerized hydrophilic monomers that form the hydrophilic component, and the hydrophilic component attached to a surface of the hydrophobic component; (ii) a ratio of polymerized hydrophobic monomers to polymerized hydrophilic monomers ranging from 5:95 to 30:70; (iii) a higher concentration of polymerized hydrophilic monomers at or near a surface of the hydrophobic component; and (iv) a core-shell structure with copolymerized hydrophobic and hydrophilic monomers at a core of the core-shell structure and a higher concentration of copolymerized hydrophilic monomers at a shell of the core-shell structure; repeating the applying of the metallic build material and the selectively applying of the binder fluid to create a patterned green part; using at least one heat source, heating the patterned green part to about a melting point of the polymer particles for a curing time period ranging from about 1 minute to about 360 minutes, thereby activating the binder fluid and creating a cured green part; using the at least one heat source, heating the cured green part to a thermal decomposition temperature of the polymer particles for a thermal decomposition time period ranging from about 10 minutes to about 72 hours, thereby creating an at least substantially polymer-free gray part; and using the at least one heat source, heating the at least substantially polymer-free gray part to a sintering temperature for a sintering time period ranging from about 20 minutes to about 15 hours to form a metallic part. ### Claim 11 (depends on 10) The method as defined in claim 10 wherein the heating of the cured green part to the thermal decomposition temperature is performed for a thermal decomposition time period ranging from about 30 minutes to about 72 hours. ### Claim 12 (depends on 10) The method as defined in claim 10 wherein: the heating of the cured green part up to the thermal decomposition temperature is accomplished at a rate ranging from about 0.5° C./minute to about 10° C./minute; and the heating of the at least substantially polymer-free gray part up to the sintering temperature is accomplished at a rate ranging from about 1° C./minute to about 20° C./minute. ### Claim 13 (depends on 10) The method as defined in claim 10 wherein: the applying of the metallic build material, the selectively applying of the binder fluid, the repeating of the applying and the selectively applying, and the heating of the patterned green part to about the melting point are accomplished on a build area platform; and after the heating of the patterned green part to about the melting point, the method further comprises: removing the cured green part from the build area platform; and placing the cured green part in a heating mechanism. ### Claim 14 (depends on 10) The method as defined in claim 10 wherein the selectively applying of the binder fluid is accomplished by thermal inkjet printing or piezo electric inkjet printing.