# US 11,111,359 B2 · Method for printing low-density polymer structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,111,359 B2 - Document ID: US11111359B2 - Status: Granted - Kind: B2 - Application number: 16/403,995 - Filed: 2019-05-06 - Published: 2019-11-07 - Granted: 2021-09-07 - Earliest claimed: 2018-05-05 - Assignees: UT-Battelle, LLC - Applicants: Ut-Battelle, LLC - Inventors: Vlastimil Kunc; John M. Lindahl; Lonnie J. Love; Brian K. Post; Ahmed Hassen; Peng Liu; Thomas Zeke Sudbury - Web page: https://patentgrep.com/patent/US11111359B2 ## CPC - B33Y 80/00: Products made by additive manufacturing - C08K 7/28: Glass - B29C 64/118: using filamentary material being melted, e.g. fused deposition modelling [FDM] - 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 70/10: Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials - C08J 3/201: {Pre-melted polymers} - C08K 7/06: Elements - B29C 64/112: using individual droplets, e.g. from jetting heads - B29K 2055/02: ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers - B29K 2077/00: Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material - B29K 2105/16: Fillers - B29K 2105/165: {Hollow fillers, e.g. microballoons or expanded particles} - B29K 2507/04: Carbon - B29K 2509/08: Glass - B29K 2995/0063: Density - B29K 2995/0064: Non-uniform density - B33Y 10/00: Processes of additive manufacturing - C08K 2201/003: Additives being defined by their diameter - 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 - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - 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) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract A method of forming a low-density three-dimensional article is provided. The method includes printing a low-density composition on a substrate to form at least one layer comprising the low-density composition. The low-density composition includes a (P) polymer component and (M) a microsphere component in a ratio by volume (P):(M). The method also includes selectively controlling a density of the low-density composition during printing to give the at least one layer on the substrate. Selectively controlling the density of the low-density composition includes varying the ratio (P):(M) during printing. The method further includes repeating the printing and selectively controlling the density of the low-density composition to form additional layer(s), thereby forming the low-density three-dimensional article. A low-density three-dimensional article prepared in accordance with the method is also provided. ## Claims ### Claim 1 A method of forming a low-density three-dimensional article, said method comprising: A) printing a low-density composition on a substrate via extrusion deposition to form at least one layer comprising the low-density composition, wherein the low-density composition is a thermoplastic comprising a polymer component (P) and a microsphere component (M) in a ratio by volume (P):(M); B) selectively controlling a density of the low-density composition during printing A) by varying the ratio (P):(M) during extrusion deposition of the low-density composition to give the at least one layer on the substrate; and C) repeating A) and B) to form additional layer(s). ### Claim 2 (depends on 1) The method of claim 1, wherein the polymer component (P) comprises an acrylonitrile-butadiene-styrene (ABS) resin. ### Claim 3 (depends on 1) The method of claim 1, wherein the polymer component (P) comprises a polyamide resin. ### Claim 4 (depends on 1) The method of claim 1, wherein the microsphere component (M) comprises hollow glass microspheres. ### Claim 5 (depends on 4) The method of claim 4, wherein the low-density composition comprises the hollow glass microspheres of the microsphere component (M) in an amount of from 10 to 50 vol. %, based on the total volume of the low-density composition. ### Claim 6 (depends on 4) The method of claim 4, wherein the hollow glass microspheres comprise soda-lime-borosilicate glass. ### Claim 7 (depends on 4) The method of claim 4, wherein the hollow glass microspheres comprise an average diameter of from 10 to 50 μm. ### Claim 8 (depends on 1) The method of claim 1, wherein the microsphere component (M) comprises expandable microspheres. ### Claim 9 (depends on 8) The method of claim 8, wherein the expandable microspheres comprise an average diameter of from 10 to 15 μm at room temperature and an average diameter of from 35 to 45 μm during printing. ### Claim 10 (depends on 8) The method of claim 8, wherein the expandable microspheres are further defined as expandable thermoplastic microspheres. ### Claim 11 (depends on 10) The method of claim 10, wherein the expandable thermoplastic microspheres each comprise a thermoplastic shell disposed about a hydrocarbon composition. ### Claim 12 (depends on 10) The method of claim 10, wherein the low-density composition comprises the expandable thermoplastic microspheres of the microsphere component (M) in an amount of from 2 to 5 wt. %, based on the total weight of the low-density composition. ### Claim 13 (depends on 1) The method of claim 1, wherein the low-density composition further comprises a carbon fiber filler. ### Claim 14 (depends on 13) The method of claim 13, wherein the low-density composition comprises the carbon fiber filler in an amount of from greater than 0 to 30 wt. % based on the weight of the polymer component (P). ### Claim 15 (depends on 1) The method of claim 1, further comprising preparing the low-density composition prior to deposition, wherein preparing the low-density composition comprises combining the polymer component (P) and the microsphere component (M) at a preparation temperature greater than a melting temperature of the polymer component (P), such that the low-density composition is flowable at the preparation temperature. ### Claim 16 (depends on 15) The method of claim 15, wherein the preparation temperature is from 190 to 260° C. ### Claim 17 (depends on 15) The method of claim 15, wherein printing A) comprises depositing the low-density composition at a printing temperature to form the at least one layer, and wherein the printing temperature is equal to or greater than the preparation temperature.