# US 7,402,273 B2 · Flash curing in selective deposition modeling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,402,273 B2 - Document ID: US7402273B2 - Status: Granted - Kind: B2 - Application number: 11/133,060 - Filed: 2005-05-19 - Published: 2005-11-17 - Granted: 2008-07-22 - Earliest claimed: 2002-05-07 - Assignees: 3D Systems, Inc. - Inventors: Michael Thomas Sherwood - Web page: https://patentgrep.com/patent/US7402273B2 ## CPC - G03F 7/0037: {Production of three-dimensional images} - B29C 35/0805: {using electromagnetic radiation} - B29C 64/112: using individual droplets, e.g. from jetting heads - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 50/02: for controlling or regulating additive manufacturing processes - B29C 2035/0827: {using UV radiation} - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - 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 flash curing system for solid freeform fabrication which generates a plurality of radiation emitting pulses that forms a planar flash. The planar flash initiates curing of a curable material dispensed by a solid freeform fabrication apparatus. The radiation emitting pulses have a high peak power value that releases a sufficient quantity of free radicals from the photoinitiator to initiate curing and overcome the problem of oxygen inhibition. Substantially less power is consumed and less heat generated by the flash curing system compared to conventional continuous emission curing systems. ## Claims ### Claim 1 A method of forming a three-dimensional object in a layerwise manner in a build environment, the method comprising the steps of: generating computer data corresponding to layers of the object; selectively dispensing a curable build material and a non-curable support material from a jetting print head in the build environment according to the computer data to form layers of the object; supporting the dispensed material in the build environment; exposing the dispensed material to at least one planar flash of radiation to cure the dispensed material, the planar flash comprising a plurality of radiation emitting high peak power pulses to release an effective amount of free radicals to overcome oxygen inhibition and to initiate curing of the dispensed material; and consuming less than about 500 watts of power when exposing the dispensed material to the at least one planar flash. ### Claim 2 (depends on 1) The method of claim 1 further comprising providing between about 1 joule to about 15 joules of input energy for generating each radiation emitting pulse. ### Claim 3 (depends on 1) The method of claim 1 further comprising providing between about 1 to about 5 joules of input energy for generating each radiation emitting pulse. ### Claim 4 (depends on 1) The method of claim 1 further comprising providing about 3.5 to about 4.5 joules of input energy for generating each radiation emitting pulse. ### Claim 5 (depends on 1) The method of claim 1 further comprising emitting an average energy density of between about 400 J/s cm2 to about 6,000 J/s cm2 from the pulses on a per second basis within the wavelength band of between about 200 nm to about 400 nm. ### Claim 6 (depends on 1) The method of claim 1 further comprising emitting radiation emitted from the pulses between the wavelengths of between about 200 to about 400 nanometers to initiate curing of the dispensed material. ### Claim 7 (depends on 1) The method of claim 1 further comprising the radiation emitting pulses each having a pulse width of between about 10 microseconds to about 4 milliseconds. ### Claim 8 (depends on 1) The method of claim 1 further comprising the radiation emitting pulses each having a pulse width of between about 20 to about 200 microseconds. ### Claim 9 (depends on 1) The method of claim 1 further comprising the radiation emitting pulses each having a pulse width of between about 70 to about 150 microseconds. ### Claim 10 (depends on 1) The method of claim 1 further comprising the radiation emitting pulses each having a pulse width of between about 90 to about 100 microseconds. ### Claim 11 (depends on 1) The method of claim 1 further comprising applying the at least one planar flash for a duration having a duty cycle of less than 100%. ### Claim 12 (depends on 1) The method of claim 1 further comprising applying the at least one planar flash for a duration having a duty cycle between about 4.1% and about 25%. ### Claim 13 (depends on 1) The method of claim 1 further comprising providing the at least one planar flash with a duration of between about 0.01 to about 2.0 seconds. ### Claim 14 (depends on 1) The method of claim 1 further comprising providing the at least one planar flash with a duration of between about 0.5 to about 1.5 seconds. ### Claim 15 (depends on 1) The method of claim 1 further comprising providing the at least one planar flash with a duration of about 1 second. ### Claim 16 (depends on 6) The method of claim 6 further comprising using a lamp to expose a planar area of at least about 10 square inches in the build environment. ### Claim 17 A method of forming a three-dimensional object in a layerwise manner in a build environment, the method comprising the steps of: generating computer data corresponding to layers of the object; selectively dispensing a curable build material and a non-curable support material from a jetting print head in the build environment according to the computer data to form layers of the object; supporting the dispensed material in the build environment; exposing the dispensed material to at least one planar flash of radiation to cure the dispensed material, the planar flash comprising a plurality of radiation emitting high peak power pulses to release an effective amount of free radicals to overcome oxygen inhibition and to initiate curing of the dispensed material; and providing between about 1 joule to about 15 joules of input energy for generating each radiation emitting pulse. ### Claim 18 (depends on 17) The method of claim 17 further comprising providing between about 1 to about 5 joules of input energy for generating each radiation emitting pulse. ### Claim 19 (depends on 17) The method of claim 17 further comprising providing about 3.5 to about 4.5 joules of input energy for generating each radiation emitting pulse. ### Claim 20 (depends on 17) The method of claim 17 further comprising emitting an average energy density of between about 400 J/s cm2 to about 6,000 J/s cm2 from the pulses on a per second basis within the wavelength band of between about 200 nm to about 400 nm. ### Claim 21 (depends on 17) The method of claim 17 further comprising emitting radiation from the pulses between the wavelengths of between about 200 to about 400 nanometers to initiate curing of the dispensed material. ### Claim 22 (depends on 17) The method of claim 17 further comprising the radiation emitting pulses each having a pulse width of between about 10 microseconds to about 4 milliseconds. ### Claim 23 (depends on 17) The method of claim 17 further comprising the radiation emitting pulses each having a pulse width of between about 20 to about 200 microseconds. ### Claim 24 (depends on 17) The method of claim 17 further comprising the radiation emitting pulses each having a pulse width of between about 70 to about 150 microseconds. ### Claim 25 (depends on 17) The method of claim 17 further comprising the radiation emitting pulses each having a pulse width of between about 90 to about 100 microseconds. ### Claim 26 (depends on 17) The method of claim 17 further comprising applying the at least one planar flash for a duration having a duty cycle of less than 100%. ### Claim 27 (depends on 17) The method of claim 17 further comprising applying the at least one planar flash for a duration having a duty cycle between about 4.1% and about 25%. ### Claim 28 (depends on 17) The method of claim 17 further comprising providing the at least one planar flash with a duration of between about 0.01 to about 2.0 seconds. ### Claim 29 (depends on 17) The method of claim 17 further comprising providing the at least one planar flash with a duration of between about 0.5 to about 1.5 seconds. ### Claim 30 (depends on 17) The method of claim 17 further comprising providing the at least one planar flash with a duration of about 1 second. ### Claim 31 (depends on 17) The method of claim 17 further comprising using a lamp to expose a planar area of at least about 10 square inches in the build environment.