# US 10,245,677 B2 · Laser decoating of coated metal sheets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,677 B2 - Document ID: US10245677B2 - Status: Granted - Kind: B2 - Application number: 14/450,419 - Filed: 2014-08-04 - Published: 2015-02-05 - Granted: 2019-04-02 - Earliest claimed: 2013-08-05 - Assignees: TRUMPF Laser- und Systemtechnik GmbH - Applicants: TRUMPF Laser- und Systemtechnik GmbH - Inventors: Severin Luzius; Florian Kiefer - Web page: https://patentgrep.com/patent/US10245677B2 ## CPC - B23K 26/0876: {in at least two axial directions} - B23K 26/142: for the removal of by-products - B23K 26/26: of rectilinear seams - B23K 26/352: for surface treatment - B23K 26/354: by melting - B23K 26/60: Preliminary treatment - B23K 37/0235: {the guide member forming part of a portal} - B23K 37/0408: {for planar work} - B23K 2101/185: {Tailored blanks} - B23K 2101/34: Coated articles {; Surface treated articles} - B23K 2103/04: Steel {or steel} alloys - B23K 2103/08: Non-ferrous metals or alloys - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM ## Abstract Methods, devices and systems for laser decoating of coated metal sheets, in particular for removing a metal protective layer from a metal sheet by a laser beam. The laser beam is directed onto a surface of a metal sheet coated with a metal protective layer, such that the laser beam strikes the surface of the metal sheet at a laser spot and melts material of the metal protective layer. A gas is directed by a plurality of nozzles at a pressure of at least 3 bar and at an acute angle with respect to the laser beam onto the laser spot. The nozzles are arranged around the laser beam such that the gas directed from the nozzles blows away the melted material of the metal protective layer from the metal sheet. ## Claims ### Claim 1 A method of laser decoating a coated metal sheet, the method comprising: directing a laser beam onto a surface of a metal sheet coated with a metal protective layer, such that the laser beam strikes the surface of the metal sheet at a laser spot and melts material of the metal protective layer; and directing multiple gas flows, from a plurality of nozzles at a pressure of at least 3 bar and at an acute angle with respect to the laser beam onto the laser spot, the nozzles being arranged around the laser beam such that the gas flows directed from the nozzles intersect with each other on the surface of the workpiece at the laser spot and blow away the melted material of the metal protective layer from the metal sheet. ### Claim 2 (depends on 1) The method of claim 1, further comprising: moving the laser beam relative to the metal sheet in an advance direction and at an advance speed over the metal sheet, to remove material of the metal protective layer from the metal sheet along the advance direction. ### Claim 3 (depends on 2) The method of claim 2, wherein at least one of the nozzles directs the gas onto the laser spot exclusively with flow components in the direction of the laser beam and in the advance direction. ### Claim 4 (depends on 2) The method of claim 2, wherein directing the gas comprises directing the gas onto the laser spot from at least three nozzles, the gas from each nozzle exiting from a pressure of at least 3 bar and at an acute angle with respect to the laser beam, and wherein only a central nozzle of the nozzles directs the gas onto the laser spot exclusively with flow components in the direction of the laser beam and in the advance direction of the laser beam. ### Claim 5 (depends on 4) The method of claim 4, wherein two outer nozzles of the nozzles each direct the gas onto the laser spot symmetrically with respect to a plane defined by the laser beam and the advance direction. ### Claim 6 (depends on 5) The method of claim 5, wherein the two outer nozzles each direct the gas onto the laser spot in an angularly offset manner through approximately 45 degrees with respect to the gas flowing out of the central nozzle. ### Claim 7 (depends on 2) The method of claim 2, further comprising: adjusting the advance speed of moving the laser beam to control a depth of melt of the protective layer. ### Claim 8 (depends on 7) The method of claim 7, further comprising: determining, based on a thickness of the metal protection layer after the melted material has been blown away, whether an intermetallic phase between a coating material and a carrier material of the metal protective layer has been removed. ### Claim 9 (depends on 1) The method of claim 1, further comprising: drawing the gas by a suction device connected to a suction channel located below a workpiece support for the coated metal sheet. ### Claim 10 (depends on 1) The method of claim 1, wherein the nozzles are each spaced from the surface of the metal sheet no more than about 5 to 8 mm. ### Claim 11 (depends on 1) The method of claim 1, wherein the laser beam strikes the surface of the metal sheet perpendicularly. ### Claim 12 (depends on 1) The method of claim 1, wherein the metal protective layer includes at least one of aluminum/silicon protective coating and zinc protective coating. ### Claim 13 (depends on 1) The method of claim 1, wherein the gas is either compressed air or an inert gas. ### Claim 14 (depends on 1) The method of claim 1, wherein the nozzles have an opening diameter of no more than about 2.5 mm, from which the gas is discharged at the pressure of at least 3 bar. ### Claim 15 A laser decoating device, comprising: a laser beam generation unit for generating a laser beam; and a laser processing head, from which the laser beam is emitted, wherein the laser processing head has a plurality of nozzles arranged around the emitted laser beam and whose nozzle axes are each directed at an acute angle with respect to the laser beam and configured to direct a gas to intersect with the emitted laser beam at a surface of a workpiece coated with a protective layer, wherein the laser processing head is configured to direct the laser beam to strike the surface of the workpiece at a laser spot and melts material of the protective layer, and wherein the plurality of nozzles is configured to direct the gas at a pressure of at least 3 bar onto the laser spot such that the gas directed from the nozzles blows away the melted material of the protective layer from the workpiece. ### Claim 16 (depends on 15) The laser decoating device of claim 15, wherein the plurality of nozzles are arranged on a common nozzle member. ### Claim 17 (depends on 15) The laser decoating device of claim 15, wherein the laser processing head has at least three nozzles, the two outer nozzles being arranged in a mirror-symmetrical manner relative to each other with respect to a plane defined by the laser beam and the nozzle axis of the central nozzle. ### Claim 18 (depends on 17) The laser decoating device of claim 17, wherein the two outer nozzles are each arranged in a manner offset through an angle of approximately 45° with respect to the central nozzle. ### Claim 19 (depends on 15) The laser decoating device of claim 15, wherein an opening diameter of the nozzles is a maximum of about 2.5 mm. ### Claim 20 (depends on 15) The laser decoating device of claim 15, further comprising a suction device connected to a suction channel located below a workpiece support for a coated metal sheet, the suction device configured to draw the gas through the suction channel during operation of the laser decoating device.