# US 7,611,756 B2 · Process for coating particles for generative rapid prototyping > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,611,756 B2 - Document ID: US7611756B2 - Status: Granted - Kind: B2 - Application number: 10/545,979 - Filed: 2004-02-13 - Published: 2006-11-09 - Granted: 2009-11-03 - Earliest claimed: 2003-02-18 - Assignees: Daimler AG - Inventors: Rolf Pfeifer; Jialin Shen - Web page: https://patentgrep.com/patent/US7611756B2 ## CPC - B01J 2/006: {Coating of the granules without description of the process or the device by which the granules are obtained (to prevent the granules sticking together B01J2/30)} - B01J 2/16: by suspending the powder material in a gas, e.g. in fluidised beds or as a falling curtain - B22F 1/10: Metallic powder containing lubricating or binding agents; Metallic powder containing organic material - B22F 1/102: Metallic powder coated with organic material - B22F 10/14: by jetting of binder onto a bed of metal powder - B22F 10/20: Direct sintering or melting - B22F 10/34: of powder characteristics, e.g. density, oxidation or flowability - 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 - B33Y 10/00: Processes of additive manufacturing - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B33Y 70/10: Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials - B22F 10/38: to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures - B22F 2998/00: Supplementary information concerning processes or compositions relating to powder metallurgy - Y02P 10/25: Process efficiency - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - 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 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The invention relates to a method for coating particles of a plastic, metal and/or ceramic powder material for producing an adhesive-containing coating material, in particular for producing appropriate particles by compressing a 3D binder. Said coating is applied to fluidized particles in a gaseous phase by means of a coating solution, at least the particles and/or coated particles being exposed to ionized particles. A method for producing bodies or sintered bodies from organic liquid binders by compressing the 3D binder and the use thereof are also disclosed. ## Claims ### Claim 1 A method for coating a plastic, metal and/or ceramic powder material with a coating containing a binder liquid activatable or laser light activatable organic or organo-meteallic adhesive, the method comprising: providing particles of the powder material to be coated in a fluidized form in a gas phase; and depositing the organic or organo-meteallic adhesive from a solution onto the particles of the powder material to form coated particles wherein the particles, the coated particles or the gas space in which the particles are present in fluidized form are exposed to sufficient ionized particles to reduce the electrostatic charging of the powder material and/or the coated powder material. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein at least the gas phase coming into contact with the coated particles is substantially water-free. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein granules which comprise the adhesive as a binding phase are formed during the coating. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the layer thickness of the coating containing the adhesive lies in the range from 40 nm to 5 μm. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein the amount of the coating lies at 0.3 to 8% by weight of the powder material. ### Claim 6 (depends on 1) The method as claimed in claim 1, the coated particles being used for producing a body, comprising the repeated sequence of the steps of: discharging a layer of powder of coated particles on an underlying surface, melting or sintering the adhesive, at least of the discharged layer of powder, by laser irradiation, wherein the energy of the laser light is substantially insufficient to melt or sinter the powder particles of the layer of powder. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein, in addition to the adhesive, further active substances are deposited onto the surface of the powder material. ### Claim 8 (depends on 7) The method as claimed in claim 7, wherein the active substances comprise polymeric, metallic or ceramic nanoparticles and/or microparticles with an average grain size below 5 μm. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the adhesive is composed of an adhesive of organic and/or organo-metallic polymers. ### Claim 10 (depends on 9) The method as claimed in claim 9, wherein the water content of the solution of the adhesive lies below 5% by weight. ### Claim 11 (depends on 1) The method as claimed in claim 1, the coated particles being used for producing a body, comprising the repeated sequence of the steps of: discharging a layer of powder of coated particles on an underlying surface, moistening defined regions of the layer of powder with a binder liquid, wherein one of the layers of powder has a thickness below 250 μm, and the binder liquid is substantially formed by organic solvents and has a water content below 45% by weight. ### Claim 12 (depends on 11) The method as claimed in claim 11, wherein the proportion of insoluble constituents in the binder liquid lies below 5% by weight. ### Claim 13 (depends on 11) The method as claimed in claim 11, wherein the amount of binder liquid used for moistening the powder lies in the range from 5 to 70% by volume of the powder volume to be coated. ### Claim 14 (depends on 11) The method as claimed in claim 11, further comprising sintering the produced body. ### Claim 15 (depends on 14) The method as claimed in claim 14, further comprising using the sintered body in foundry practice, in mold making or in tool making.