# US 2017/0282452 A1 · System and method for additive manufacturing of an object > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0282452 A1 - Document ID: US20170282452A1 - Status: Published application - Kind: A1 - Application number: 15/626,219 - Filed: 2017-06-19 - Published: 2017-10-05 - Earliest claimed: 2010-11-28 - Assignees: Stratasys, Inc. - Applicants: Stratasys Ltd. - Inventors: Diana RAVICH; Eduardo NAPADENSKY - Web page: https://patentgrep.com/patent/US20170282452A1 ## CPC - B29C 64/393: for controlling or regulating additive manufacturing processes - B29C 64/112: using individual droplets, e.g. from jetting heads - B33Y 10/00: Processes of additive manufacturing - B33Y 50/02: for controlling or regulating additive manufacturing processes - 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 ## Abstract A method of additive manufacturing of a three-dimensional object is disclosed. The method comprises sequentially forming a plurality of layers in a configured pattern corresponding to the shape of the object. Each layer is formed by dispensing at least one modeling material to form an uncured layer, and curing the uncured layer by radiation. In various exemplary embodiments of the invention the method comprises, for at least one layer, forming a stack of sacrificial radiation-protective layers to cover an exposed portion of the layer, such that an upper layer of the stack remains exposed during formation of any subsequent layer of the plurality of layers. ## Claims ### Claim 1 A system for additive manufacturing of a three-dimensional object, comprising; a dispensing unit configured for dispensing at least one type of modeling material to form an uncured layer; a curing unit configured for curing said uncured layer by radiation; and a controller configured for operating said dispensing unit and said curing unit to sequentially form a plurality of layers in a configured pattern corresponding to the shape of the three-dimensional object, and a stack of sacrificial radiation-protective layers covering an exposed portion of at least one layer, such that an upper layer of said stack remains exposed during formation of any subsequent layer of said plurality of layers. ### Claim 2 (depends on 1) The system according to claim 1, wherein a number of layers in said stack is selected so as to block at least 90% of said radiation. ### Claim 3 (depends on 1) The system according to claim 1, wherein each stack has at least 10 layers. ### Claim 4 (depends on 1) The system according to claim 1, wherein each stack has at least 30 layers. ### Claim 5 (depends on 1) The system according to claim 1, wherein each stack has at least 60 layers. ### Claim 6 (depends on 1) The system according to claim 1, wherein each stack has at least 90 layers. ### Claim 7 (depends on 1) The system according to claim 1, wherein each layer in said stack is at least 5 microns in thickness. ### Claim 8 (depends on 1) The system according to claim 1, wherein each layer in said stack is at least 10 microns in thickness. ### Claim 9 (depends on 1) The system according to claim 1, wherein each layer in said stack is at least 15 microns in thickness. ### Claim 10 (depends on 1) The system according to claim 1, wherein each layer in said stack is at least 30 microns in thickness. ### Claim 11 (depends on 1) The system according to claim 1, wherein said controller is configured for operating said dispensing unit and said curing unit to form a plurality of stacks of sacrificial radiation-protective layers. ### Claim 12 (depends on 1) The system according to claim 1, wherein said sacrificial radiation-protective layers are made, at least in part, from a three-dimensional printing support material. ### Claim 13 (depends on 1) The system according to claim 1, wherein said sacrificial radiation-protective layers are made, at least in part, from a water soluble material. ### Claim 14 (depends on 1) The system according to claim 1, wherein said sacrificial radiation-protective layers are characterized by a modulus of elasticity which is lower than a modulus of elasticity characterizing said modeling material once cured. ### Claim 15 (depends on 1) The system according to claim 1, wherein said sacrificial radiation-protective layers comprise unpolymerizable material. ### Claim 16 (depends on 1) The system according to claim 1, wherein said stack is selected such as to form an object which is generally uniform in color. ### Claim 17 (depends on 1) The system according to claim 1, wherein said stack is selected such as to form an object which is generally uniform in lack of color. ### Claim 18 (depends on 1) The system according to claim 1, wherein said controller is configured for calculating a thickness of said stack based on a type of a radiation-protective material used for forming said stack. ### Claim 19 (depends on 1) The system according to claim 1, wherein said controller is configured for calculating a number of layers in said stack based on a type of a radiation-protective material used for forming said stack. ### Claim 20 A computer software product, comprising a computer-readable medium in which program instructions are stored, which instructions, when read by a computerized controller of an additive manufacturing system having a dispensing unit and a curing unit, cause said controller to operating said dispensing and curing units to sequentially form a plurality of layers in a configured pattern corresponding to the shape of a three-dimensional object, and a stack of sacrificial radiation-protective layers covering an exposed portion of at least one layer, such that an upper layer of said stack remains exposed during formation of any subsequent layer of said plurality of layers.