# US 11,897,187 B2 · Method and system for additive manufacturing of peelable sacrificial structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,897,187 B2 - Document ID: US11897187B2 - Status: Granted - Kind: B2 - Application number: 16/914,392 - Filed: 2020-06-28 - Published: 2020-10-22 - Granted: 2024-02-13 - Earliest claimed: 2017-12-28 - Assignees: Stratasys, Inc. - Applicants: Stratasys Ltd. - Inventors: Mayan Rumbak; Eduardo Napadensky; Gavish Mida - Web page: https://patentgrep.com/patent/US11897187B2 ## CPC - B29C 64/112: using individual droplets, e.g. from jetting heads - B29C 64/106: using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material - B29C 64/209: Heads; Nozzles - B29C 64/40: Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 70/10: Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials - B29K 2033/12: {Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate} - B29K 2509/08: Glass - B29K 2995/0021: Multi-coloured - B29K 2995/0098: Peel strength; Peelability - 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 method of additive manufacturing of a three-dimensional object includes sequentially dispensing and solidifying a plurality of layers. The plurality of layers may be formed with a plurality of different colored model materials, a flexible material arranged in a configured pattern to form a sacrificial structure at least partially encompassing the object, and a soft material. The soft material is arranged in a configured pattern to provide separation between the model material and the sacrificial structure. The plurality of different colored model materials is arranged in a configured pattern corresponding to the shape and color definition of the object. ## Claims ### Claim 1 A method of additive manufacturing of a three-dimensional object comprising: sequentially dispensing and solidifying a plurality of layers, wherein the plurality of layers is formed with (i) a plurality of different colored model materials arranged in a configured pattern corresponding to a shape and a color definition of the object, (ii) a flexible material arranged in a configured pattern to form a sacrificial structure at least partially encompassing the object, and (iii) a soft material arranged in a configured pattern to provide an intermediate structure between the model material and the sacrificial structure; wherein the flexible material is black, wherein the plurality of different color model materials does not include a black model material, and wherein at least one first black portion of the object is formed by digitally mixing the plurality of different colored model materials to create a black color, and at least one second black portion of the object is formed by an amount of said black flexible material. ### Claim 2 (depends on 1) The method of claim 1, wherein the soft material is arranged in a configured pattern to form divisions in the sacrificial structure, to fill holes defined by geometry of the object or both. ### Claim 3 (depends on 1) The method of claim 1, wherein the soft material is configured to encompass features susceptible to breaking if a pulling or peeling force is applied to features adjacent thereto. ### Claim 4 (depends on 1) The method of claim 1, wherein the soft material is formed from a gel that is water soluble. ### Claim 5 (depends on 1) The method of claim 1, wherein a thickness of the intermediate structure between the model material and the sacrificial structure provided by the soft material is 100 microns to 300 microns. ### Claim 6 (depends on 1) The method of claim 1, wherein a minimal thickness of the sacrificial structure is from about 500 microns to about 3 mm. ### Claim 7 (depends on 1) The method of claim 1, wherein a flexural modulus of at least a portion of the model material is 2000 MPa to 4000 MPa. ### Claim 8 (depends on 1) The method of claim 1, wherein the sacrificial structure is characterized, once solidified, by a tear resistance of from about 4 kN per meter to about 8 kN per meter, when measured according to international standard ASTM D-624. ### Claim 9 (depends on 1) The method of claim 1, wherein the sacrificial layer is configured to be peeled and wherein a magnitude of the peeling force is from about 1 N to about 20 N. ### Claim 10 (depends on 1) The method of claim 1, wherein the flexible material is a formulation comprising silica particles, wherein when hardened the formulation is characterized by a tear resistance which is higher by at least 0.5 kN per meter than, a solidified formulation having the same flexible material but devoid of the silica particles, and wherein the silica particles have an average particle size less than 1 micron. ### Claim 11 (depends on 10) The method according to claim 10, wherein at least a portion of the silica particles comprise functionalized silica particles that are functionalized by curable functional groups, wherein the curable functional groups comprise (meth)acrylate groups. ### Claim 12 (depends on 10) The method according to claim 10, wherein the flexible material includes one or more of: a mono-functional elastomeric monomer, a mono-functional elastomeric oligomer, a multi-functional elastomeric monomer, multi-functional elastomeric oligomer. ### Claim 13 (depends on 10) The method according to claim 10, wherein the formulation comprises at least one of an additional curable material, an elastomeric mono-functional curable material, an elastomeric multi-functional curable material, and an additional mono-functional curable material. ### Claim 14 (depends on 1) The method according to claim 1, wherein the flexible material is a UV-curable elastomeric material. ### Claim 15 (depends on 1) The method of claim 1, wherein the flexible material is an acrylic elastomer.