# US 11,993,722 B2 · Twice recycled polymer powder composition for additive manufacturing including PEKK, siloxane and carbon fiber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,722 B2 - Document ID: US11993722B2 - Status: Granted - Kind: B2 - Application number: 16/422,283 - Filed: 2019-05-24 - Published: 2020-11-26 - Granted: 2024-05-28 - Earliest claimed: 2019-05-24 - Assignees: Hexcel Corporation - Applicants: Hexcel Corporation - Inventors: Whitney Kline; Alden Winn; Lawrence Varholak - Web page: https://patentgrep.com/patent/US11993722B2 ## CPC - C09D 11/102: containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B33Y 10/00: Processes of additive manufacturing - 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 - C09D 11/037: characterised by the pigment - B29C 64/20: Apparatus for additive manufacturing; Details thereof or accessories therefor - B29K 2071/00: Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - 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 - 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 powder composition suitable for use in selective laser sintering for printing an object. The powder composition includes a first fraction having a polyetherketoneketone (PEKK) powder having a plurality of particles. The powder composition includes a second fraction having a plurality of siloxane particles that is dry blended with the PEKK powder prior to selective laser sintering of the powder. In some embodiments, the powder composition includes a third fraction of carbon fiber. The powder composition when used in selective laser sintering results in parts with more consistent results and improves process economics. ## Claims ### Claim 1 A powder composition suitable for use in selective laser sintering for printing a three-dimensional object, the powder composition comprising: a first fraction comprising a recycled polyetherketoneketone (PEKK) powder having a plurality of PEKK particles, the plurality of PEKK particles having a mean diameter between 30 μm to 90 μm; a second fraction comprising a siloxane powder having a plurality of siloxane particles; a third fraction comprising carbon fiber, the third fraction is between 5% and 25% of the composition by weight; wherein the recycled PEKK powder has been previously used in a first SLS build having a bed temperature between an upper melting point of the PEKK before the first SLS build (TM1) and 20° C. less than TM1; wherein the recycled PEKK powder has been previously used in a second SLS build having a bed temperature between an upper melting point of the PEKK after the first SLS build and before the second SLS build (TM2) and 20° C. less than TM2; wherein the plurality of siloxane particles having a mean diameter between 30 μm to 60 μm; wherein the second fraction is between 0.5% and 1.5% of the composition by weight. ### Claim 2 (depends on 1) The powder composition of claim 1 wherein the third fraction is 15% of the composition by weight. ### Claim 3 (depends on 2) The composition of claim 2 wherein the plurality of siloxane particles having a mean diameter between 40 μm to 50 μm. ### Claim 4 (depends on 3) The composition of claim 3, wherein the second fraction is 1.0% of the composition by weight. ### Claim 5 (depends on 1) A method for a layer-wise manufacturing of a three-dimensional object from the powder composition according to claim 1, comprising the steps of: applying a layer of a powder composition on a bed of a laser sintering machine, the powder composition is the powder of claim 1; solidifying selected points of the applied layer of powder by irradiation; successively repeating the step of applying the powder and the step of solidifying the applied layer of recycled powder until all cross sections of a three-dimensional object are solidified. ### Claim 6 (depends on 5) The method of claim 5, wherein the object formed has a strain to failure of at least 2.0%. ### Claim 7 (depends on 5) The method of claim 5, wherein the object formed has a strain to failure greater than a strain to failure of an object made from a PEKK powder composition excluding siloxane powder. ### Claim 8 A method of preparing a powder composition suitable for use in laser sintering for printing a three-dimensional object, the method including the steps of: providing a first fraction comprising a polyetherketoneketone (PEKK) powder having a plurality of PEKK particles; providing a third faction comprising carbon fiber; mixing the first fraction and the third fraction to form a mixture; preparing recycled PEKK from the mixture by the following steps: heating the mixture in a first SLS build having a bed temperature between an upper melting point of the PEKK before the first SLS build (TM1) and 20° C. less than TM1; heating the mixture in a second SLS build having a bed temperature between an upper melting point of the PEKK after the first SLS build and before the second SLS build (TM2) and 20° C. less than TM2; providing a second fraction comprising a siloxane powder having a plurality of siloxane particles, the plurality of siloxane particles having a mean diameter between 30 μm to 90 μm; mixing the recycled PEKK powder with the siloxane powder to obtain a powder composition suitable for use in selective laser sintering; wherein the third fraction is between 5% and 25% of the composition by weight; wherein the second fraction is between 0.5% and 1.5% of the composition by weight. ### Claim 9 (depends on 8) The method of claim 8 wherein the mixing of the PEKK powder and the siloxane powder comprises dry blending. ### Claim 10 (depends on 8) The method of claim 8, wherein the third fraction is 15% of the composition by weight, the plurality of siloxane particles having a mean diameter between 40 μm to 50 μm, and the second fraction is 1.0% of the composition by weight.