Line and method for producing a metal strip with cutting on the fly

Abstract

The invention relates to a line for producing a metal strip (4), the production line comprising a plurality of treatment units for carrying out successive treatments of the metal strip travelling through the treatment units along a path of travel, the treatment units including a laser cutting unit (44) configured to cut the metal strip (4) during the travel of the metal strip, the cutting unit (44) comprising at least one laser cutting device (46), each laser cutting device (46) being arranged to generate a laser beam and to direct same so as to cut the metal strip (4).

Description

[0001] Line and process for producing a metal strip with cutting on the run

[0002] The present invention relates to a line and a method for producing a metal strip, made for example of steel, in particular stainless steel.

[0003] It is possible to subject a metal strip to a heat treatment in the flow by continuously running the metal strip in a furnace, and then to a pickling in the flow by continuously running the metal strip in a pickling unit to remove any unwanted oxide layer that may have formed at high temperature in contact with an oxidizing atmosphere such as air, during the heat treatment.

[0004] A production line for implementing such treatments generally includes a cutting unit for cutting the metal strip, for example for cutting edges of the metal strip or slitting the metal strip to then form coils.

[0005] Such a cutting unit includes, for example, knives. It may be necessary to replace the knives in case of wear or to reposition the knives, for example for a production change. This requires temporarily stopping the cutting unit, and therefore the production line, which is costly and can lead to the loss of metal strips.

[0006] Furthermore, in the case of edge cutting, the offcuts can be difficult to handle and can lead to jams or failure of the cutting unit, requiring a stoppage of the production line and therefore possible losses of metal strips.

[0007] One of the aims of the invention is to propose a production line for the treatment of a metal strip allowing efficient treatment of the metal strip and which is simple to implement.

[0008] To this end, the invention proposes a production line for a metal strip, the production line comprising several processing units for carrying out successive treatments of the metal strip as it moves through the processing units along a moving path, the processing units including a laser cutting unit configured for cutting the metal strip as the metal strip moves, the cutting unit comprising at least one laser cutting device, each laser cutting device being arranged to generate a laser beam and direct it to cut the metal strip. Carrying out laser cutting as it moves allows for simple, rapid and efficient processing of the metal strip that can be easily integrated into a production line ensuring the metal strip moves.

[0009] The cutting can be adapted easily and very quickly depending on the metal strip, for example by adapting the parameters of a laser beam or the position of the laser beam to make the desired cut(s).

[0010] According to particular embodiments, the production line comprises one or more of the following optional features, taken individually or in all technically possible combinations:

[0011] - the cutting unit being configured for cutting edges of the metal strip;

[0012] - the cutting unit being configured for cutting offcuts resulting from cutting the edges into fragments;

[0013] - the cutting unit being configured for slitting the metal strip;

[0014] - the cutting unit being configured for cutting the metal strip;

[0015] - the cutting unit being configured for cutting shapes in the metal strip;

[0016] - the cutting unit comprises at least one laser cutting device configured for precise cutting;

[0017] - the production line comprises at least one laser cutting device configured for high-speed cutting;

[0018] - the cutting unit comprises a position detection device configured to detect a position of the metal strip in the cutting unit, in particular a longitudinal position of the metal strip 4 and / or a transverse position of the metal strip, and to transmit a position signal, representative of the position of the metal strip to each laser cutting device, each laser cutting device being configured to position a laser beam according to the position of the metal strip detected by the position detection device;

[0019] - the position detection device comprises one or more position sensors for detecting the position of the metal strip;

[0020] - the position sensor(s) include one or more optical position sensors for optical detection of the position of the metal strip and / or one or more laser position sensors;

[0021] - the position sensor(s) include one or more image sensors, the detection of the position of the metal strip being carried out by processing the images provided by each image sensor, for example by an electrical detection unit; - the processing units comprise a reel unwinding station located at the upstream end of the travel path for unwinding the metal strip from a reel;

[0022] - the processing units comprise a winding station located at a downstream end of the scroll path for winding the metal strip into at least one coil;

[0023] - the laser cutting unit is located along the travel path between the unwinding station and the winding station, the production line comprising at least one additional processing unit, located for example between the unwinding station and the laser cutting unit along the travel path;

[0024] - the treatment units comprise a heat treatment furnace, preferably induction, and / or a stripping unit, preferably laser;

[0025] - the treatment units comprise a unit for removing a layer of organic material covering one or each surface of the metal strip, preferably by laser;

[0026] - the processing units comprise a stripping unit configured to cut one or more ligatures from a coil of metal strip, in particular by cutting each ligature by laser;

[0027] - the processing units comprise a welding unit configured for welding a rear end of the metal strip to a front end of another metal strip.

[0028] The invention also relates to a method for producing a metal strip, comprising running the metal strip through several processing units, following a running path, for carrying out successive treatments of the metal strip in the processing units, the production method comprising laser cutting the metal strip during the running of the metal strip, in one of the processing units defining a laser cutting unit.

[0029] In particular implementation examples, the production method comprises one or more of the following optional features, taken individually or in any technically possible combination:

[0030] - the production method comprises detecting a position of the metal strip in the laser cutting unit, in particular a longitudinal position of the metal strip 4 and / or a transverse position of the metal strip, and adjusting the position of each laser beam generated in the laser cutting unit according to the position of the detected metal strip; - the position of the metal strip is detected optically, by capturing images of the metal strip and processing the images to detect the position of the metal strip, and / or by laser.

[0031] The invention and its advantages will be better understood upon reading the following description, given solely as a non-limiting example, and made with reference to the appended drawings, in which:

[0032] - Figure 1 is a schematic overview of a metal strip production line comprising a laser cutting unit;

[0033] - Figure 2 is a schematic side view of the laser cutting unit of Figure 1;

[0034] - Figure 3 is a schematic top view of the laser cutting unit of Figure 2.

[0035] As illustrated in Figure 1, a production line 2 is configured to process a metal strip 4.

[0036] The production line 2 is preferably a continuous production line configured for continuous production of a metal strip 4.

[0037] The production line 2 comprises a plurality of treatment units, each treatment unit being configured to carry out a treatment on the metal strip 4, the production line 2 being configured so that the metal strip 4 passes successively through the treatment units for the sequential carrying out of the treatments.

[0038] The production line 2 comprises in particular a cutting unit 44 configured to cut the metal strip 4 by laser.

[0039] The cutting unit 44 is configured to perform one or more cuts of the metal strip 4 during the movement, i.e. during the movement of the metal strip 4 through the production line 2 and, in particular, through the cutting unit 44.

[0040] The cutting unit 44 is for example configured to cut edges of the metal strip 4 and, optionally, to cut into fragments the offcuts resulting from the cutting of each edge and / or to slit the metal strip 4, i.e. to cut it lengthwise, and / or to section the metal strip 4, i.e. to cut it widthwise, and / or to cut shapes in the metal strip 4.

[0041] Cutting the edges of the metal strip 4 makes it possible, for example, to obtain a suitable finish for the edges of the metal strip 4.

[0042] Cutting the offcuts from the edge cutting process into fragments avoids the hassle of jamming and waste disposal. Cutting into fragments also allows for better material recovery by allowing it to be injected further downstream in the production process than other raw materials, for example for the production and refining of metal.

[0043] Slitting the metal strip 4 makes it possible, for example, to form several narrow metal strips from a wide metal strip. Each narrow metal strip can be wound to form a coil.

[0044] The sectioning of the metal strip 4 makes it possible, for example, to form metal strips 4 of the desired length or to separate, at the output of the production line 2, metal strips 4 previously assembled at the input of the production line 2 for their passage into the production line 2 one after the other.

[0045] Cutting shapes makes it possible to obtain plates or sides of the desired contour directly from production line 2.

[0046] Such a laser cutting unit 44 replaces in particular a mechanical cutting unit configured to cut the metal strip by shearing using knives, the latter having to be replaced regularly, which requires stopping the production line and negatively impacts productivity. Furthermore, in such a mechanical cutting unit, the position of the knives is fixed during operation of the production line and can only be adjusted during a stoppage of the production line. Laser cutting also has the advantage over knife cutting that the burr is much lower or even non-existent and therefore less disruptive for subsequent stages of processing the metal strip 4 or shapes cut from the metal strip 4.

[0047] The cutting unit 44 comprises one or more laser cutting devices 46.

[0048] Each laser cutting device 46 comprises for example a laser 46A for generating a laser beam L, an optical device 46B configured to shape the laser beam L, a positioning device 46C configured to modify the position, and in particular the orientation, of the laser cutting device 46 so as to position the laser beam L relative to the metal strip 4, and an electronic control unit 46D, configured to control the laser 46A, the optical device 46B and the positioning device 46C to generate an appropriate laser beam L, put the laser beam in an appropriate shape and move the laser beam L appropriately to perform a cut of the metal strip 4.

[0049] The parameters of the laser beam L emitted by the laser 46 include, for example, a wavelength of the laser beam, a pulse duration of the laser beam, a frequency of the laser beam, and a power of the laser beam. The parameters of the laser beam L shaped by the optical device of each laser device 46 include, for example, a diameter of the focal spot of the laser beam on the metal strip 4.

[0050] Each positioning device 46C is for example configured to move the laser cutting device 46 in translation.

[0051] Each positioning device 46C is for example a motorized axis configured to move the laser cutting device 46 in translation along a translation axis A.

[0052] The translation axis A of each positioning device 46C is preferably transverse relative to the metal strip 4. The movement of the metal strip 4 causes a longitudinal displacement of each positioning device 46C relative to the metal strip 4.

[0053] The positioning device 46C makes it possible to position the laser beam L dynamically, for example to carry out a longitudinal slitting cut, a transverse sectioning cut or a shape cut in the metal strip 4.

[0054] Preferably, each laser cutting device 46 comprises a gas ejection device 46E configured to emit a flow of cutting gas GC towards the focal spot of the laser beam L on the metal strip 4. The cutting gas GC is for example ejected at a pressure of between 5 bar and 30 bar. The cutting gas GC is for example nitrogen (N2). The cutting gas GC makes it possible to avoid a reaction of the material of the metal strip 4 with the surrounding atmosphere, while this material is heated by the laser beam L to carry out the cutting. The cutting gas GC also helps to evacuate the molten material, in particular the sparks, and therefore participates in the cutting.

[0055] In Figure 3 which represents the cutting unit 44 in top view, the laser beam L of each laser cutting device 46 is symbolized by a point corresponding to the focal spot of the laser beam L on the metal strip 4.

[0056] As illustrated, the cutting unit 44 comprises for example two laser cutting devices 46 arranged for cutting edges 48 of the metal strip 4, each being arranged to cut a respective edge 48 of the metal strip 4.

[0057] Each edge cutting laser device 46 produces an edge cutting line LR extending along the length of the metal strip 4 along an edge thereof. Optionally or alternatively, the cutting unit 44 comprises two edge cutting laser devices 46 arranged for cutting edges 48 into fragments 50, each being arranged to cut a respective edge 48 into fragments 50.

[0058] Optionally or alternatively, the cutting unit 44 comprises one or more laser cutting devices 46 arranged for slitting the metal strip 4, i.e. for cutting the metal strip 4 lengthwise into a plurality of narrow metal strips each less wide than the initial metal strip 4.

[0059] Each laser cutting device 46 arranged to perform slitting performs a cut of the metal strip 4 along a longitudinal cutting line LL extending along the length of the metal strip 4.

[0060] As illustrated in Figure 3, the cutting unit 44 comprises a laser cutting device 46 arranged for slitting the metal strip 4 into two narrow metal strips. In other examples, the cutting unit 44 is configured for slitting the metal strip 4 into more than two narrow metal strips, i.e. into three or more narrow metal strips.

[0061] Optionally or alternatively, the cutting unit 44 comprises one or more laser cutting devices 46 arranged for sectioning the metal strip 4, i.e. for cutting the metal strip 4 perpendicular to the direction of its length.

[0062] Each laser cutting device 46 for sectioning produces a transverse cutting line LT extending along the width of the metal strip 4.

[0063] Optionally or alternatively, the cutting unit 44 comprises one or more laser cutting devices 46 arranged for cutting shapes in the metal strip 4.

[0064] Cutting a shape from the metal strip 4 comprises, for example, cutting the metal strip 4 along longitudinal rectilinear lines, transverse rectilinear lines, oblique rectilinear lines (i.e. neither longitudinal nor transverse) and / or curvilinear lines.

[0065] Offcuts resulting from cutting shapes in the metal strip 4 can be cut into fragments, like offcuts resulting from cutting edges.

[0066] Each laser cutting device 46 is, for example, configured for precise cutting or high-speed cutting.

[0067] A laser cutting device 46 configured for precise cutting is configured for more precise but slower positioning of its laser beam L and each laser cutting device 46 configured for high-speed cutting is configured for less precise but faster positioning of its laser beam L. The accuracy and speed of positioning of the laser beam L of each laser cutting device 46 are a function of the accuracy and speed of its positioning device 46C.

[0068] Each 46C positioning device configured for precise cutting is, for example, a motorized axis with a positioning accuracy equal to or less than 25 pm.

[0069] Each 46C positioning device configured for high-speed cutting is, for example, a motorized axis allowing a movement speed greater than 1 m / s and / or an acceleration equal to or greater than 50 m / s 2 .

[0070] Each cut of the edge cutting, slitting or sectioning type of the metal strip 4 is preferably carried out using one or more laser cutting devices 46 configured for precision cutting.

[0071] One or more of these cuts may optionally be performed using one or more laser cutting devices 46 configured for high-speed cutting, particularly if the cutting precision is sufficient.

[0072] The cutting of the edges 48 into fragments 50 is preferably carried out by one or more laser cutting devices 46 configured for high-speed cutting.

[0073] In examples, the cutting unit 44 is configured to detect the position of the web 4 and to adjust the position of the laser beam L generated by each laser cutting device 46 based on the position of the detected web.

[0074] The cutting unit 44 comprises for example a position detection device 52 configured to detect the position of the metal strip 4 in the cutting unit 44, in particular the longitudinal position of the metal strip 4 (along the direction of movement D) and / or the transverse position of the metal strip 4 (perpendicular to the direction of movement D).

[0075] The position detection device 52 is preferably configured to transmit a position signal, representative of the position of the metal strip 4, to at least one laser cutting device 46, preferably to each laser cutting device 56.

[0076] Each laser cutting device 46, in particular the electrical control unit 46D of each laser cutting device 46, is configured to control the positioning device 46C to position the laser beam L appropriately according to the position of the detected metal strip 4, to perform cutting of the metal strip 4.

[0077] The position detection device 52 comprises one or more position sensors 52A and an electrical detection unit 52B configured to determine the position of the metal strip 4 as a function of the signals provided by each position sensor 52A and to transmit a position signal representative of the position of the metal strip 4 to at least one laser cutting device 46, preferably to each laser cutting device 46.

[0078] Each position sensor 52A is for example an optical position sensor, an image sensor, the position of the metal strip being achieved by processing the images provided by the image sensor, or a laser position sensor.

[0079] The position sensor(s) 52A include one or more optical position sensors, one or more image sensors, and / or one or more laser position sensors.

[0080] Each position sensor 52A (optical position sensor, image sensor or laser position sensor) is arranged for example at the inlet of the cutting unit 44 or in the cutting unit 44.

[0081] In operation, the production line 2 implements a method for producing a metal strip 4 comprising cutting the metal strip 4.

[0082] The cutting is carried out using at least one laser cutting device 46, each laser cutting device 46 being arranged to cut the metal strip 4.

[0083] Each cut is made on the run, i.e. during the running of the metal strip 4 along the running path C, without interruption of the running of the metal strip 4.

[0084] The cutting comprises cutting edges of the metal strip 4, cutting offcuts resulting from cutting each edge into fragments, slitting the metal strip 4, sectioning the metal strip 4 and / or cutting a shape in the metal strip 4.

[0085] Examples of implementation, each laser cutting device 46 is controlled to perform a cut with a power between 50 W and 50 kW.

[0086] Preferably, each laser cutting device 46 is controlled to perform a cut with a focal spot diameter equal to or less than 40 μm.

[0087] Preferably, each laser cutting device 46 is controlled to perform a cut under a cutting gas jet at a pressure of between 5 bar and 30 bar, the cutting gas being in particular nitrogen (N2).

[0088] In an exemplary embodiment, a flow cut is carried out on a metal strip 4 made of 1.4310 steel according to the European standard having a thickness of 0.1 mm running at a speed of 320 m / min with a cutting width of 120 μm. The cutting is obtained without generating a heat-affected zone (HAZ) and without burr. In an exemplary embodiment, a flow cut is carried out on a metal strip 4 made of 1.4307 steel according to the European standard having a thickness of 2.5 mm running at a speed of 24 m / min with a cutting width of 225 μm. The cutting is obtained with a heat-affected zone (HAZ) 14 μm wide and a burr zone 14 μm wide on each side of the cut.

[0089] These examples highlight that laser cutting on the scroll allows to obtain a very good cutting quality on a thin metal strip (first example: no burrs, no HAZ) and that the cutting quality decreases when the thickness of the metal strip 4 is increased (second example: appearance of a burr and a HAZ), but decreases less than with cutting carried out using knives. The scroll speeds indicated are maximum scroll speeds for this level of quality.

[0090] Preferably, the method comprises detecting the position of the metal strip 4 and adjusting the position of each laser beam L according to the position of the detected metal strip 4.

[0091] The detection of the position of the metal strip 4 comprises in particular the longitudinal position of the metal strip 4 and / or the transverse position of the metal strip 4.

[0092] The detection is carried out for example using one or more position sensors, arranged for example at the inlet of the cutting unit 44 or in the cutting unit 44, the position sensors including one or more optical position sensors, one or more image sensors, the position of the metal strip 4 being determined by processing the images provided by each image sensor, and / or one or more laser position sensors.

[0093] Returning to Figure 1, the production line 2 is configured to run the metal strip 4 along a running path C passing through the cutting unit 44.

[0094] The production line 2 comprises, for example, in a known manner, guide rollers 6 distributed along the running path C and making it possible to define the running path C. The metal strip 4 rests on the guide rollers 6. The guide rollers 6 comprise guide rollers 6 arranged to deflect the metal strip 4 and possibly pinching guide rollers 6 which are associated in pairs, the two pinching guide rollers 6 of each pair defining between them a slot through which the metal strip 4 passes. The production line 2 is for example configured to carry out a heat treatment of the metal strip 4, in particular an annealing heat treatment, and a surface pickling treatment 4A of the metal strip 4.

[0095] The treatment units comprise a furnace 8 configured for the heat treatment of the metal strip 4 as it passes (i.e. during the passing of the metal strip 4) and a pickling unit 10 configured for the pickling of at least one surface 4A of the metal strip 4 as it passes. The pickling unit 10 is located downstream of the furnace 8 along the passing path C.

[0096] The furnace 8 is preferably an induction furnace configured to heat the metal strip 4 by electromagnetic induction as the metal strip 4 travels.

[0097] The furnace 8 is configured to generate an electromagnetic field crossed by the metal strip 4 during the movement of the metal strip 4 in the furnace 8, so as to generate induced electric currents circulating in the metal strip 4, the circulation of the induced electric currents generating heat in the metal strip 4 by Joule effect, so that the metal strip 4 is heated.

[0098] The furnace 8 comprises electromagnetic inductors 12. Each electromagnetic inductor 12 is capable of generating an electromagnetic field crossed by the metal strip 4 when the metal strip 4 passes through the furnace 8. Each electromagnetic inductor 12 is for example an electromagnet.

[0099] In exemplary embodiments, the furnace 8 comprises one or more electromagnetic inductors 12 which are each configured to generate a variable electromagnetic field during the movement of the metal strip 4.

[0100] Thus, the metal strip 4 passes through the variable electromagnetic field of each of these electromagnetic inductors 12, which generates the circulation of induced electric currents in the metal strip 4 and causes the heating of the metal strip 4.

[0101] Alternatively or optionally, the furnace 8 comprises several electromagnetic inductors 12 distributed along the travel path C, being configured to generate identical and / or different electromagnetic fields from one electromagnetic inductor 12 to another during the travel of the metal strip 4.

[0102] Thus, the metal strip 4 moving opposite these electromagnetic inductors 12 is exposed to an electromagnetic field of variable intensity, which generates the circulation of induced electric currents in the metal strip 4 and causes the heating of the metal strip 4.

[0103] An example of an induction furnace for heating a metal strip as this metal strip travels is described in FR2808163A1. The pickling unit 10 is configured to be traversed by the metal strip 4 as the metal strip 4 travels along the travel path C.

[0104] The stripping unit 10 is preferably configured for laser stripping each surface 4A to be stripped of the metal strip 4.

[0105] The stripping unit 10 comprises at least one laser device 14, and preferably several laser devices 14, each laser device 14 being configured to strip a surface 4A of the metal strip 4 moving in the stripping unit 10.

[0106] A unit for stripping a moving metal strip is disclosed for example in WO2018096382.

[0107] In exemplary embodiments, the stripping unit 10 comprises several laser devices 14 distributed along the travel path C so as to strip the two opposite surfaces 4A of the metal strip 4.

[0108] In exemplary embodiments, the stripping unit 10 comprises several laser devices 14 distributed along the travel path C to strip each surface 4A of the metal strip 4.

[0109] The provision of several laser stripping devices 14 distributed along the travel path C for stripping the same surface 4A of the metal strip 4 makes it possible to strip this surface 4A in several passes.

[0110] Optionally, the stripping unit 10 comprises support rollers 16 arranged to guide the metal strip 4 in the stripping unit 10, each stripping laser device 14 being arranged to strip a portion of the metal strip 4 resting on a support roller 16. This makes it possible to control the flatness of the surface to be stripped opposite each stripping laser device 14, and thus to guarantee the quality of the stripping.

[0111] In exemplary embodiments, as illustrated in Figure 1, the support rollers 16 are arranged for a zig-zag movement of the metal strip 4 in the stripping unit 10, with an alternation of left turns and right turns in which the metal strip 4 is curved, stripping laser devices 14 being distributed along the movement path alternately on one side and the other of the movement path C, each stripping laser device 14 pointing at a portion of the metal strip 4 resting on a support roller 16.

[0112] Preferably, the production line 2 has an oxide measuring unit 72 arranged along the travel path between the furnace 8 and the pickling unit 10, the oxide measuring unit 72 being configured to measure one or more oxidation parameters of one or more surfaces of the metal strip 4, the pickling unit 10 being configured to adjust the laser pickling parameters as a function of the oxidation parameter(s) measured for said surface(s) of the metal strip 4.

[0113] Oxidation parameters include, for example, oxide composition, ablation threshold (laser energy density), oxide thickness, and / or emissivity.

[0114] The laser stripping parameters adjusted according to the oxidation parameters comprise, for example, one or more of the following parameters: a wavelength of the laser beam emitted by each stripping laser device 14, the frequency of the laser beam emitted by each stripping laser device 14, the power of the laser beam emitted by each stripping laser device 14, the pulse duration of the laser beam emitted by each stripping laser device 14 (in the case of a pulsed stripping laser device 14), the pulse energy of the laser beam emitted by each stripping laser device 14 (in the case of a pulsed stripping laser device 14), the scanning speed of the laser beam emitted by each stripping laser device 14, the overlap rate between the laser beams emitted by adjacent stripping laser devices 14,the laser-material interaction time of the laser beam emitted by each stripping laser device 14 and / or the overlap parameters between the laser impacts of the laser beam emitted by each stripping laser device 14,

[0115] The oxide measuring unit 72 comprises for example a characterization device for characterizing the oxide layer, for example a sensor for measuring one or more oxidation parameters of each surface of the metal strip 4 stripped by the stripping unit 10.

[0116] In particular, the oxide measurement unit 72 comprises for example a characterization device which is an oxidation measurement sensor 74 for measuring one or more oxidation parameters of each of the two opposite surfaces of the metal strip 4.

[0117] Each oxidation measurement sensor 74 comprises for example a camera arranged to take images of an associated surface 4A of the metal strip 4, the oxide measurement unit 72 being configured for the automatic analysis of the images captured by each camera to determine the oxidation parameters.

[0118] Preferably, the furnace 8 and the pickling unit 10 are arranged vertically, that is to say so that the metal strip 4 runs vertically through the furnace 8 and the pickling unit 10. This makes it possible to limit the horizontal size of the production line 2.

[0119] The vertical scrolling of the metal strip 4 in the furnace 8 also makes it possible to limit the number of guide rollers 6 required in the furnace 8 and thus to limit the risk of marking the metal strip 4 with the guide rollers 6 in the furnace 8 or at the outlet of the furnace 8, when the metal strip 4 is hot and sensitive to marking.

[0120] The vertical scrolling of the metal strip 4 in the furnace 8 still allows good control of the position of the metal strip 4 relative to the electromagnetic inductors 12, which makes it possible to arrange the electromagnetic inductors 12 close to the metal strip 4 for good efficiency of induction heating.

[0121] Advantageously, the oven 8 and the pickling unit 10 are arranged side by side. This makes it possible to limit the horizontal space requirement of the production line 2.

[0122] Preferably, the furnace 8 and the pickling unit 10 are arranged one on an ascending section of the scroll path C, in which the metal strip 4 rises vertically, and the other on a descending section of the scroll path C, in which the metal strip 4 descends vertically.

[0123] In exemplary embodiments, the oven 8 is arranged on an upward section C1 of the scroll path C, and the stripping unit 10 is arranged on a downward section C2 of the scroll path C.

[0124] If necessary, intermediate guide rollers 6 are arranged between the furnace 8 and the stripping unit 10 to effect a change in direction of the scroll path between the furnace 8 and the stripping unit 10.

[0125] Optionally, such intermediate guide rollers 6 are cooled, for example by air and / or water. This makes it possible to cool the metal strip 4 guided by these intermediate guide rollers 6.

[0126] In exemplary embodiments, the production line 2 comprises a cooling unit 18 configured to actively cool the metal strip 4 as the metal strip 4 travels.

[0127] The cooling unit 18 is for example configured to force air circulation along the metal strip 4 to cool the metal strip 4.

[0128] Optionally or alternatively, the cooling unit 18 is for example configured to cool the metal strip 4 by water, for example by spraying water onto the metal strip 4, in particular atomized or non-atomized water.

[0129] The cooling unit 18 is arranged along the scroll path C downstream of the furnace 8 and, preferably, upstream of the pickling unit 10.

[0130] In exemplary embodiments, the cooling unit 18 is arranged on the same ascending or descending section of the scroll path C on which the oven 8 is arranged.

[0131] In particular, and as illustrated in Figure 1, the cooling unit 18 is arranged on an upward section C1 of the scroll path C on which the furnace 8 is arranged, before a change of direction towards a downward section C2 of the scroll path C on which the pickling unit 10 is arranged.

[0132] Air cooling is more suitable than water cooling when the cooling unit 18 is located on the same vertical section of the scroll path as the furnace 8.

[0133] The provision of cooled intermediate guide rollers 6 as mentioned above makes it possible to limit the length or the cooling capacity of the cooling unit 18.

[0134] Optionally, the production line 2 comprises a defect correction unit 80 arranged along the travel path C downstream of the pickling unit 10 and configured to detect and treat surface defects of one or more surfaces of the metal strip 4, in particular oxidation points not pickled or insufficiently pickled by the pickling unit 10.

[0135] The defect correction unit 80 is for example configured to detect and process surface defects on each surface 4A of the metal strip 4.

[0136] The defect correction unit 80 comprises, for example, for each surface 4A of the metal strip 4, one or more defect sensors 82 and one or more correction laser devices 84, each correction laser device 84 being configured to emit a laser beam towards the surface of the metal strip 4 to remove a possible surface defect, for example to remove one or more oxidation points present on the surface of the metal strip 4.

[0137] Each defect sensor 82 is for example a camera configured to take images of the associated surface of the metal strip 4, the defect correction unit 80 being configured to automatically analyze the images taken by each defect sensor 82 to determine the possible presence of surface defects to be treated.

[0138] In exemplary embodiments, the production line 2 comprises an unwinding station 20 located at the upstream end of the scroll path C for unwinding the metal strip 4 from an input reel 22.

[0139] In exemplary embodiments, the production line 2 comprises a winding station 24 located at a downstream end of the scroll path C for winding the metal strip 4 to form one or more output coils 26.

[0140] In exemplary embodiments, the production line 2 comprises a welding unit 28 configured to weld a rear end of the metal strip 4 of a previous input coil 22 to a front end of another metal strip 4 of a subsequent input coil 22. This allows the production of metal coils 4 continuously from several successive input coils 22 by connecting the input coils 22 to each other.

[0141] Preferably, the production line 2 comprises a cutting unit 30 configured for cutting a rear end of a previous input reel 22 and / or cutting a front end of a subsequent input reel 22.

[0142] The cutting unit 30 is located along the scroll path C upstream of the welding unit 28.

[0143] Cutting a trailing end of a previous input coil 22 and / or cutting a leading end of a subsequent input coil 22 allows for clean welding of the two coils 22.

[0144] The treatment units advantageously comprise a removal unit 32 configured to remove a layer of organic material from one or each surface 4A of the metal strip 4.

[0145] The removal unit 32 is for example located along the scroll path C upstream of the furnace 8, and, where appropriate, downstream of a welding unit 28 and / or a cutting unit 30.

[0146] Organic material such as oil may be applied to one or each surface 4A of the metal strip 4 to protect the surface 4A and / or for performing treatments on the metal strip 4.

[0147] The removal unit 32 is configured to remove organic matter by laser.

[0148] The removal unit 32 comprises one or more laser removal devices 34 arranged to remove organic matter from at least a portion of each surface 4A to be treated of the metal strip 4.

[0149] The removal unit 32 is for example configured for the removal of organic material from the two opposite surfaces 4A of the metal strip 4. The removal unit 32 comprises laser removal devices 34 arranged on either side of the metal strip 4 received in the removal unit 32.

[0150] Each laser removal device 34 is configured to generate a laser beam and project the laser beam onto a surface 4A of the metal strip 4 to remove a layer of organic material H covering this surface 4A.

[0151] Each laser removal device 34 is for example configured to generate a laser beam having the effect of evaporating the layer of organic matter H covering the surface 4A.

[0152] In addition or as a variant, each laser removal device 34 is for example configured to generate a laser beam having the effect of pushing or scraping a layer of organic material H covering this surface 4A due to a movement of the metal strip 4 relative to the laser beam generated by the laser removal device 34.

[0153] The pushing or scraping of the layer of organic matter H is in particular obtained using a laser beam configured to pass through the oil layer, strike the surface 4A of the metal strip 4 and heat said surface 4A of the metal strip 4 in such a way as to cause local evaporation of the organic matter at the interface with the surface 4A of the metal strip 4 and generate an overpressure which lifts and pushes the layer of organic matter H along the metal strip 4 due to the movement of the metal strip 4 relative to the laser beam generated by the laser removal device 34. This can be obtained without damaging the metal strip 4, and in particular without damaging the surface 4A of the metal strip 4.

[0154] Adjustable parameters of the laser beam of each removal device 34 include, for example, a wavelength of the laser beam emitted by the removal laser device 34, the frequency of the laser beam emitted by the removal laser device 34, the power of the laser beam emitted by the removal laser device 34, the pulse duration of the laser beam emitted by the removal laser device 34 (in the case of a laser pulsed removal laser device 34), the pulse energy of the laser beam emitted by the removal laser device 34 (in the case of a laser pulsed removal laser device 34), the scanning speed of the laser beam emitted by the removal laser device 34, the overlap rate between the laser beams emitted by adjacent removal laser devices 34, the laser-material interaction time of the laser beam emitted by the removal laser device 34,the overlap parameters between the laser impacts of the laser beam emitted by the laser removal device 34.,

[0155] As illustrated in Figure 1, the removal unit 32 is configured for gravity flow of the organic material removed from one or each surface 4A of the metal strip 4. This allows for efficient removal and facilitates recovery of the organic material removed from the surface 4A.

[0156] Optionally, the removal unit 32 comprises one or more tanks 36 for recovering the grease removed from the metal strip 4, in particular by gravity flow.

[0157] In exemplary embodiments, as illustrated in Figure 1, the removal unit 32 comprises several guide rollers 35 arranged to deflect the metal strip 4, each removal laser device 34 being arranged opposite a guide roller 35 to project a beam onto a surface 4A of the metal strip 4 opposite the guide rollers 35 and inclined relative to a horizontal plane and preferably substantially parallel to a vertical plane. A recovery tank 36 is preferably arranged under the guide roller 35 to recover the organic material removed from the other surface 4A and flowing by gravity into the recovery tank 36.

[0158] In exemplary embodiments, the production line 2 comprises a planing unit 38 located along the scroll path C downstream of the stripping unit 10.

[0159] The planing unit 38 is configured to flatten the metal strip 4, in particular to flatten deformations which could have been caused by the passage of the metal strip 4 along the running path C.

[0160] The planing unit 38 comprises, for example, in a known manner, planing rollers 40 arranged to reduce the deformations of the metal strip 4, for example thanks to a particular arrangement and / or rollers with external diameters that vary from one planing roller 40 to another.

[0161] Alternatively, the planishing unit 38 is a skin pass mill comprising a pair of skin pass rolls arranged for the metal strip 4 to pass between the two skin pass rolls while being pressed between the two skin pass rolls.

[0162] In exemplary embodiments, the production line 2 comprises an inspection unit 42 configured for the inspection of the metal strip 4.

[0163] The inspection unit 42 is for example configured for an optical inspection of the metal strip 4.

[0164] The inspection unit 42 comprises for example one or more image capture devices arranged to capture images of the metal strip 4 and a data processing unit (not shown) configured to automatically analyze the captured images.

[0165] The inspection unit 42 is arranged along the scroll path C downstream of the stripping unit 10, and, where appropriate, downstream of the planing unit 38.

[0166] The production line 2 comprises the cutting unit 44 arranged for example along the scroll path C downstream of the stripping unit 10, and, where appropriate, downstream of the leveling unit 38 and / or downstream of the inspection unit 42.

[0167] The production line 2 optionally comprises a position adjustment device 54 configured to adjust the position of a length portion of the metal strip 4 in an adjustment section of the travel path C, the metal strip 4 remaining stationary along the travel path C upstream and downstream of the adjustment section.

[0168] The position adjustment device 54 is in particular configured to advance or retreat said portion of length of the metal strip 4 in the adjustment section, the movement of the remainder of the metal strip 4 being interrupted upstream and downstream of the adjustment section.

[0169] The adjustment section comprises, for example, the furnace 8 and the pickling unit 10. The position adjustment device 54 makes it possible to adjust the position of the length portion of the metal strip 4 located in the furnace 8 and the pickling unit 10. The adjustment section here comprises the first section C1 and the second section C2.

[0170] The adjustment of the position of said portion of the metal strip 4 makes it possible, for example, when an unplanned interruption in the running of the metal strip 4 occurs, to move said portion of length of the metal strip 4 back several meters in the adjustment section, to reposition it relative to the furnace 8 and to the pickling unit 10, so as to resume production without having to reject the metal strip 4.

[0171] The inclusion of the furnace 8 and the pickling unit 10 in the adjustment section makes it possible to ensure the resumption of the treatment of said portion of length by including heating and pickling.

[0172] If necessary, the cooling unit 18 arranged between the furnace 8 and the pickling unit 10 is preferably included in the adjustment section.

[0173] Where appropriate, the defect correction unit 80 arranged downstream of the stripping unit 10 is preferably included in the position adjustment section in which the position adjustment device 54 makes it possible to advance or retreat the metal product 4 along the travel path C.

[0174] This makes it possible to correct the defects of a portion of the length of the metal product 4 which has been moved back in the position adjustment section and then moved forward again for treatment in the furnace 8 and the pickling unit 10.

[0175] In exemplary embodiments, the furnace 8, the pickling unit 10 and, where appropriate, the cooling unit 18 and / or the defect correction unit, are the only units of the production line 2 included in the position adjustment section of the position adjustment device 8.

[0176] The position adjustment device 54 preferably makes it possible to move the length portion of the metal strip 4 located in the adjustment section with a maximum amplitude of movement at least equal to the length of the furnace 8.

[0177] The position adjustment device 54 is for example configured to jointly modify the length of the scrolling path in an upstream section C3 located upstream of the adjustment section and a downstream section C4 located downstream of the adjustment section, an elongation of the upstream section C3 causing a shortening of the downstream section C4 and, conversely, a shortening of the upstream section C3 causing an elongation of the downstream section C4.

[0178] Preferably, the position adjustment device 54 is configured in such a way that an elongation of the upstream section C3 by a certain length causes a shortening of the downstream section C4 by the same length and, conversely, that a shortening of the upstream section C3 by a certain length causes an elongation of the downstream section C4 by the same length.

[0179] A joint lengthening of the upstream section C3 and shortening of the downstream section C4 makes it possible to pull the metal strip 4 backwards in the adjustment section, and therefore to move the metal strip 4 back in the adjustment section, the metal strip 4 remaining stationary upstream and downstream of the adjustment section.

[0180] A joint shortening of the upstream section C3 and lengthening of the downstream section C4 makes it possible to pull the metal strip forward in the adjustment section, and therefore to advance the metal strip 4 in the adjustment section, the metal strip 4 remaining stationary upstream and downstream of the adjustment section.

[0181] The length adjustment device 54 comprises for example a mobile assembly 56 carrying a first roller 58 for guiding the metal strip 4 in the upstream section C3 and a second roller 56 for guiding the metal strip 4 in the downstream section C4, a first movement of the mobile assembly 56 (Arrow F1 in Figure 1) jointly causing an elongation of the upstream section C3 and a shortening of the downstream section C4, and a second movement of the mobile assembly 56 (Arrow F2 in Figure 1) jointly causing a shortening of the upstream section C3 and an elongation of the downstream section C3.

[0182] The mobile assembly 56 is for example mobile along a trajectory, the first movement and the second movement being movements of the mobile assembly 56 along the trajectory in a first direction of movement and a second opposite direction of movement.

[0183] The moving assembly 56 is for example movable in translation along a direction of movement. The trajectory of the moving assembly 56 is then rectilinear. The direction of movement is for example vertical.

[0184] Advantageously, the mobile assembly 56 is vertically movable with a displacement amplitude at least equal to the length of the first section C1 and / or the length of the second section C2. This allows a displacement of the portion of length of the metal strip 4 located in the adjustment section by a length at least equal to that of the furnace 8. When adjusting the position of the metal strip 4 in the adjustment section when the running of the metal strip 4 in the production line 2 is interrupted, the metal strip 4 remains stationary in an input section C5 located between the upstream end of the running path C and the upstream section C3 and in an output section C6 located between the downstream section C4 and the downstream end of the running path C.

[0185] It is possible to carry out a position adjustment of the metal strip 4 during a run of the metal strip 4 in the production line 2, for example during a restart of the production line 2, the position adjustment device 54 being for example used to move back the length portion of the metal strip 4 present in the adjustment section.

[0186] In a manner similar to what has already been indicated for the laser cutting device(s) 46, each laser device, whether it is a stripping laser device 14, a degreasing laser device 34, a correction laser device 84 or a stripping laser device, comprises for example, in a known manner, a laser for generating a laser beam, an optical device configured to shape and direct the laser beam towards a surface to be treated of the metal strip 4, and an electronic control unit configured to control the laser and the optical device to generate an appropriate laser beam, put the beam in an appropriate shape and direct the beam in an appropriate manner.

[0187] In operation, the production line 2 implements a method for producing a metal strip 4 in which the metal strip 4 is scrolled along the scroll path C.

[0188] In exemplary embodiments, the production method comprises induction heat treatment of the metal strip 4 in the furnace 8 and then laser stripping at least one surface of the metal strip 4 in the stripping unit 10.

[0189] The production method advantageously comprises the detection of surface defects, in particular oxidation points, downstream of the pickling unit 10, for example by capturing and analyzing images of each pickled surface on the metal strip 4, and the laser treatment of each detected surface defect, for example in a laser defect correction unit 80.

[0190] The production method preferably comprises unwinding the metal strip 4 from an input coil 22 upstream of the running path C, for example in an unwinding station 20, possibly after unstrapping the input coil 22 in a unstrapping unit, preferably a laser unstrapping unit, and / or winding the metal strip 4 to form an output coil 26 downstream of the running path C, for example in a winding station 24.

[0191] The production method preferably comprises cutting a rear end of the metal strip 4 and / or welding a rear end of the metal strip 4 to a front end of a subsequent metal strip 4.

[0192] The production process includes, for example, the removal of organic material from the metal strip 4.

[0193] The removal of organic material is carried out using at least one laser removal device 34.

[0194] The production method advantageously comprises the active cooling of the metal strip 4 between the induction heat treatment and the laser stripping, for example by passing through a cooling unit 18 located along the travel path C between the furnace 8 and the stripping unit 10.

[0195] The production method preferably comprises the planing of the metal strip 4 downstream of the pickling unit 10 along the running path C. The planing is carried out in a planing unit 38, which is for example a finishing rolling mill (or “skin pass” rolling mill) or a planer.

[0196] The production method comprises cutting the metal strip 4, the cutting including one or more cutting operations, chosen for example from cutting edges 48, with optionally cutting into fragments 50 each cut edge 48, slitting the metal strip 4, sectioning the metal strip 4 and cutting shapes in the metal strip 4.

[0197] The production method advantageously comprises adjusting the position of a portion of the length of the metal strip 4 in the furnace 8 and the pickling unit 10 by jointly adjusting the length of an upstream section C3 of the travel path C located upstream of the furnace 8 and the length of a downstream section C4 of the travel path C located downstream of the pickling unit 10, an elongation of the upstream section C3 being accompanied by a shortening of the downstream section C4 and vice versa.

[0198] The adjustment is carried out using the mobile assembly 56 carrying a roller 58 for guiding the metal strip 4 in the upstream section C3 and a roller 58 for guiding the metal strip 4 in the downstream section C4, a movement of the mobile assembly 56 in a first direction jointly causing an elongation of the upstream section C3 and a shortening of the downstream section C4, a movement of the mobile assembly 56 in a second direction jointly causing a shortening of the upstream section C3 and an elongation of the downstream section C4. The production line 2 combining an induction furnace 8 and a laser stripping unit 10 allows efficient production with a reduced footprint.

[0199] The induction furnace 8 has low inertia, particularly lower than that of a gas furnace. An induction furnace 8 allows the heating temperature of the metal strip 4 to be changed quickly and can be stopped and started quickly.

[0200] A laser stripping unit 10 also has the advantage of being able to be stopped and started quickly, unlike a stripping unit by passing through one or more stripping baths, requiring the metal strip 4 to be kept in each stripping bath for a given time.

[0201] Thus, for the welding of a following coil of metal strip to a preceding coil of metal, it is possible to stop the production line 2, in particular by stopping the furnace 8, the pickling unit 10 and the running of the metal strip 4 during the welding of the following metal strip, then to restart the production line 2 once the welding has been carried out.

[0202] Production line 2, combining an induction furnace 8 and a laser stripping unit 10, eliminates the need for accumulators, or at least limits the range of length adjustments.

[0203] Preferably, the production line 2 is devoid of an accumulator for accumulating a length of the metal strip 4.

[0204] The absence of an accumulator allows for a compact production line 2, and limits maintenance of production line 2.

[0205] The speed of modification of the settings of the induction furnace 8 and the laser pickling unit 10 and their fine adjustment make it possible to use the production line 2 to treat different metal strips by connecting them one behind the other for their passages in the production line 2 or to carry out different heat treatments and / or pickling on two separate sections of the same metal strip.

[0206] Production line 2 allows 4 different metal strips to be processed one after the other, with very rapid adaptation of the operating parameters of furnace 8 and pickling unit 10.

[0207] It is not necessary to carry out production campaigns of the same metal strip 4 by operating the production line 2 for a long period of time with the same settings, as may be the case with a gas furnace or a dip-pickling unit.

[0208] Since production can be changed quickly, there is no need to have a large stock of the same metal strip to carry out a long production campaign. There is also no need to provide transition metal strips to carry out production campaign changes.

[0209] It is also possible to limit losses around a welding zone of a metal strip 4 and another metal strip 4 processed one after the other in the production line.

[0210] The stop and restart capacity of production line 2 makes it possible to limit the waste produced, for example, such as that produced during the shutdown of a gas furnace whose cooling inertia is very high.

[0211] Furthermore, the induction furnace 8 and the pickling unit 10 use electricity as an energy source, which makes it possible to have a production line 2 powered exclusively by electricity, without the need for a gas supply, for example.

[0212] Each of the additional processing units performing laser processing (removal unit 32, correction unit 80, cutting unit 40) allows great flexibility and ease of use, with the possibility of interrupting and resuming the operation of production line 2 or modifying the production carried out using production line 2, and easy maintenance.

[0213] In particular, a laser removal unit 32 makes it possible to remove a layer of organic material easily, by quickly adapting the operating parameters of the laser removal unit 32 according to the metal strip 4 being treated.

[0214] A laser cutting unit 44 allows various cuts to be made, for example with the possibility of slitting the metal strip 4, sectioning the metal strip 4 or cutting shapes in the metal strip 4.

[0215] Cutting is easily adjusted and maintenance is easy, especially compared to a shear cutting unit using knives that make a predetermined cut and wear out and need to be changed regularly.

Claims

AMENDED CLAIMS received by the International Bureau on June 11, 2025 (11.06.2025) CLAIMS 1. Production line for a metal strip (4), the production line comprising several processing units for carrying out successive treatments of the metal strip as it moves through the processing units along a moving path, the processing units including a laser cutting unit (44) configured for cutting the metal strip (4) as the metal strip (4) moves, the cutting unit comprising at least one laser cutting device (46), each laser cutting device (46) being arranged to generate a laser beam and direct it to cut the metal strip (4), each laser cutting device (46) comprising a positioning device (46C), the positioning device (46C) being a motorized axis having a positioning accuracy equal to or less than 25 gm, and / or allowing a movement speed greater than 1 m / s and / or an acceleration equal to or greater than 50 m / s2 .

2. Production line according to claim 1, the cutting unit (44) being configured for cutting edges of the metal strip (4).

3. Production line according to claim 2, the cutting unit (44) being configured for cutting offcuts resulting from cutting the edges into fragments.

4. Production line according to any one of the preceding claims, the cutting unit (44) being configured for slitting the metal strip (4).

5. Production line according to any one of the preceding claims, the cutting unit (44) being configured for cutting the metal strip (4).

6. Production line according to any one of the preceding claims, the cutting unit (44) being configured for cutting shapes in the metal strip (4).

7. Production line according to any one of the preceding claims, wherein the cutting unit (44) comprises a position detection device (52) configured to detect a position of the metal strip (4) in the cutting unit (44), in particular a longitudinal position of the metal strip 4 and / or a transverse position of the metal strip (4), and to transmit a position signal, representative of the position of the metal strip (4) to each laser cutting device (46), each laser cutting device (46) being configured to position a laser beam (L) as a function of the position of the metal strip (4) detected by the position detection device (52).

8. Production line according to claim 7, wherein the position detection device (52) comprises one or more optical position sensors and / or one or more laser position sensors for optical detection of the position of the metal strip (4).

9. Production line according to claim 7 or 8, wherein the position detection device (52) comprises one or more image sensors for detecting the position of the metal strip (4) by capturing an image of the metal strip (4) and processing the images for optical detection of the position of the metal strip (4).

10. A production line according to any preceding claim, wherein the processing units comprise a coil unwinding station (20) located at the upstream end of the travel path for unwinding the metal strip from a coil.

11. Production line according to any one of the preceding claims, wherein the processing units comprise a winding station (24) located at a downstream end of the scroll path for winding the metal strip (4) into at least one coil.

12. Production line according to claims 7 and 8, wherein the laser cutting unit (44) is located along the travel path between the unwinding station (20) and the winding station (24), the production line comprising at least one additional processing unit, located for example between the unwinding station (20) and the laser cutting unit (44) along the travel path (C).

13. Production line according to any one of the preceding claims, in which the treatment units comprise a heat treatment furnace (8), preferably induction, and / or a pickling unit (10), preferably laser.

14. Production line according to any one of the preceding claims, in which the treatment units comprise a unit (32) for removing a layer of organic material covering one or each surface of the metal strip (4), preferably by laser.

15. Production line according to any one of the preceding claims, wherein the processing units comprise a stripping unit configured to cut one or more ligatures from a coil of metal strip, in particular by cutting each ligature by laser.

16. Production line according to any one of the preceding claims, wherein the processing units comprise a welding unit (28) configured for welding a rear end of the metal strip (4) to a front end of another metal strip.

17. Production line according to any one of the preceding claims, in which each laser cutting device (46) is controlled to carry out cutting with a power of between 50 W and 50 kW.

18. Production line according to any one of the preceding claims, in which each laser cutting device (46) is controlled to perform a cut with a focal spot diameter equal to or less than 40 μm.

19. Production line according to any one of the preceding claims, in which each laser cutting device (46) is controlled to carry out cutting under a jet of cutting gas at a pressure of between 5 bar and 30 bar, the cutting gas being in particular nitrogen.

20. A method of producing a metal strip (4), comprising running the metal strip (4) through a plurality of processing units, along a running path, for carrying out successive treatments of the metal strip (4) in the processing units, the production method comprising laser cutting the metal strip (4) during the running of the metal strip (4), in one of the processing units defining a laser cutting unit (44).

21. Production method according to claim 20, wherein, the cutting unit (44) comprising at least one laser cutting device (46), arranged to cut the metal strip, each laser cutting device (46) generates a laser beam and directs it to cut the metal strip (4).

22. Production method according to claim 21, comprising detecting a position of the metal strip (4) in the laser cutting unit (44), in particular a longitudinal position of the metal strip 4 and / or a transverse position of the metal strip (4), and adjusting the position of each laser beam (L) generated in the laser cutting unit (44) depending on the position of the detected metal strip (4).

23. Production method according to claim 22, wherein the position of the metal strip (4) is detected using one or more optical position sensors and / or using one or more laser position sensors.

24. A production method according to claim 22 or 23, wherein the position of the metal strip (4) is detected by capturing images of the metal strip (4) and processing the images to detect the position of the metal strip (4).

25. A production method according to any one of claims 21 to 24, wherein each laser cutting device (46) comprises a positioning device (46C), the positioning device (46C) being a motorized axis having a positioning accuracy equal to or less than 25 pm, and / or allowing a movement speed greater than 1 m / s and / or an acceleration equal to or greater than 50 m / s 2 .

26. Production method according to any one of claims 21 to 25, wherein each laser cutting device (46) is controlled to perform cutting with a power of between 50 W and 50 kW.

27. A production method according to any one of claims 21 to 26, wherein each laser cutting device (46) is controlled to perform a cut with a focal spot diameter equal to or less than 40 pm.

28. Production method according to any one of claims 21 to 27, in which each laser cutting device (46) is controlled to carry out cutting under a jet of cutting gas at a pressure of between 5 bar and 30 bar, the cutting gas being in particular nitrogen.

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