METHOD FOR MANAGING THE GLOSS OF AN ORGANIC COATING AND COATING LINE ON A COIL

Description

1 / 49 “METHOD FOR MANAGING THE GLOSS OF AN ORGANIC COATING AND COATING LINE ON A COIL” Field of invention

[001] The present invention relates to a method for controlling the gloss of an organic coating applied to a moving strip in a coil coating line. In particular, the moving strip is a steel strip with a metallic coating. Background of the Invention

[002] Coil coating is a continuous, automated process for coating metals prior to manufacturing into finished products. The steel or aluminum substrate is delivered in coil form from the rolling mills. The metal coil is positioned at the beginning of the coil coating line and, in a continuous process, the coil is unwound, pre-cleaned, pre-treated, pre-primed, and pre-painted before being rewound at the other end and packaged for shipment.

[003] The product obtained by this process is a pre-painted metal, also known as coil-coated metal, pre-finished metal, or pre-coated metal. It is commonly used in construction applications as well as in household appliances.

[004] The inks traditionally used for coil coating are solvent-based inks. However, there has been recent interest in radiation curing, which is the curing of materials using ultraviolet (UV processes) or electron beam (EB curing processes). The corresponding inks, known as energy-cured inks, are solvent-free, and the curing process is triggered by exposure to high-energy UV light, possibly in conjunction with suitable photoinitiators, or by exposure to accelerated electrons. The photoinitiators absorb UV light and generate free radicals. These react with double bonds of monomers, Petition 870250099315, dated 10 / 30 / 2025, page 10 / 125 2 / 49 causing a chain reaction and polymerization. For UV-C and electron beam (EB) curing, initiators are not required. The high radiant energy produces enough reactive species (radicals) for polymerization to occur spontaneously.

[005] One of the specificities of energy-cured paints is that they generate organic coatings with high gloss due to the high surface tension of the coating. To reduce this gloss and meet the requirements of pre-painting markets (gloss typically between 15 and 30 GU for the construction market), paint suppliers add matting agents, as is done with solvent-based paints. However, since energy-cured paints are quite viscous due to the absence of solvent, only small amounts of matting agent can be added, which does not allow for low gloss levels. Furthermore, the migration of matting agents to the coating surface to achieve the desired gloss level is also very limited due to the speed of the curing process of energy-cured paints compared to solvent-based paints (12 seconds versus 12-25 seconds).

[006] One way to mitigate this problem is known in document WO81 / 00683, which describes a curing process in which the coating is first irradiated with curing radiation at wavelengths to which the coating responds, but without substantial distribution below about 300 nm (such as UV), and subsequently irradiated with curing radiation at wavelengths to which the coating responds, including substantial radiation at wavelengths below 300 nm (such as EB). This double curing is known as double curing. Gloss control is achieved by adjusting parameters online, including the spectral distribution, the intensity or dose of the initial radiation, or the time interval between the initial and subsequent irradiation steps. Petition 870250099315, dated 10 / 30 / 2025, page 11 / 125 3 / 49

[007] However, it was observed that these online parameters are not sufficient to manage brightness efficiently and reproducibly. Brief Description of the Invention

[008] The objective of the present invention is, therefore, to remedy the disadvantages of the prior art process by providing a method for efficiently and reproducibly managing the gloss of an organic coating formed by applying and curing a wet film of energy-cured ink on a moving strip in a coil coating line.

[009] For this purpose, a first object of the present invention consists of a method for managing the gloss of an organic coating formed by applying and curing a wet film of an energy-cured ink onto a moving strip in a coil coating line comprising, sequentially along the path P of the moving strip, an ink applicator, a cooling device comprising a cooling module, an ultraviolet curing device and an electron beam curing device, the method comprising the steps of: - Define a defined gloss value Gs for the organic coating and a defined gloss range Rs for the organic coating gloss. - Collect the G-gloss measurement of the organic coating on at least a portion of the width downstream of the electron beam curing device. - Correcting a deviation in measured brightness G beyond the defined brightness range Rs, this correction step consisting of a sub-step for calculating the correction CP to be applied to the cooling module power, taking into account Gs and the measured brightness G, with a closed-loop controller, and a sub-step for adjusting a coil coating line configuration, taking into account the calculated correction CP. [ 010] The method according to the invention may also have the Petition 870250099315, dated 10 / 30 / 2025, page 12 / 125 4 / 49 optional features are listed below, considered individually or in combination: The closed-loop controller is a proportional-integral-derivative controller. CP correction is a function of the difference between Gs and the measured brightness G. - The CP correction to be applied to the cooling module power is calculated according to equation 1: CP(t) = Kpei(t) + KtJ0 ei(τ)άτ + Kd^P (1) where Kp is the proportional gain, Ki is the integral gain, Kd is the derivative gain and e1 is the difference between Gs and the measured brightness G, - The data collection stage also includes collecting the temperature measurement T of the wet film in at least one portion of the width of the moving strip upstream of the ultraviolet curing device. - The correction stage also includes a sub-stage for calculating the corrected temperature Tc to be reached by the wet film, in at least a portion of the width downstream of the cooling module and upstream of the ultraviolet curing device. The corrected temperature Tc is calculated according to equation 2: Tc = f1 (T, G, Gs) (2) where f1 is a function of a predefined mathematical relationship between the wet film temperature before ultraviolet curing and the gloss of the organic coating after electron beam curing, The corrected temperature Tc is calculated according to equation 3: Tc = T + K (G - Gs) (3) Petition 870250099315, dated 10 / 30 / 2025, page 13 / 125 5 / 49 The CP correction is a function of the difference between Tc and the measured temperature T. - The CP correction to be applied to the cooling module power is calculated according to equation 4: CP(t) = K'pe2(t) + K'tJ0 β2(τ)άτ + K'di-~- (4) where K'p is the proportional gain, K'i is the integral gain, K'd is the derivative gain and e2 is the difference between Tc and the measured temperature T, The method also includes an initial line adjustment step in which: • A plurality of process parameters and / or strip specifications are collected, • At least one initial line condition between the initial power PW0 of the cooling module, the initial UV dose D0 of the ultraviolet curing device, and the initial length L0 between the ultraviolet curing device and the electron beam curing device is defined, taking into account the process parameters and / or strip specifications that were collected, - The sub-step of adjusting a coil coating line configuration comprises adjusting the cooling module power through CP correction, - The ultraviolet curing device comprises a UV module, The adjustment stage also includes setting a minimum temperature Tmin for the energy-cured ink. - The data collection phase also includes collecting the UV D dose from the UV module. - The sub-step of adjusting a coil coating line configuration comprises: Petition 870250099315, dated 10 / 30 / 2025, page 14 / 125 6 / 49 • Assess whether Tc is less than Tmin, • If not, adjust the cooling module power using the Cp correction, • If Tc is less than Tmin: * Calculate the CD correction to be applied to the UV dose to which the wet film, at least in part of its width, must be exposed in the UV module, according to equation 5: CD = f2 (G, Gs) (5) * Adjust a coil coating line setting different from the cooling module power, taking into account the calculated CD correction, - The sub-step of adjusting a coil coating line configuration other than the cooling module power comprises adjusting the UV module power so that the wet film in at least a portion of the moving strip width is exposed to the corrected UV dose Dc = D + CD, The UV module is mobile along path P. The adjustment step also includes defining a minimum UV dose Dmin to which the wet film can be exposed in the UV module. The collection stage also includes collecting the wavelength L between the UV module and the electron beam curing device. - The sub-step of adjusting a coil coating line configuration, other than the cooling device power, comprises: * Assess whether D + CD is less than Dmin, * If not, adjust the UV module power so that the wet film in at least a portion of the width of the moving strip is exposed with the corrected UV dose Dc = D + CD, Petition 870250099315, dated 10 / 30 / 2025, page 15 / 125 7 / 49 * If D + CD is less than Dmin: • Calculation of the CL correction to be applied to the length between the UV module and the electron beam curing device, according to equation 6: CL = f3 (G, Gs) (6) • adjustment of a coil coating line configuration different from the cooling module power and UV module power, taking into account the calculated CL correction, - The sub-step of adjusting a coil coating line configuration different from the cooling module power and the UV module power comprises adjusting the length between the UV module and the electron beam curing device to the corrected length Lc = L + CL, so that the gloss value Gs is obtained in the organic coating in at least a portion of the width of the moving strip downstream of the electron beam curing device. The cooling module is chosen from a forced-air cooler, a water-spray cooler, a water-air spray cooler, and a roller cooler.

[011] A second object of the invention consists of a coil coating line comprising sequentially an ink applicator, a cooling device comprising a cooling module, an ultraviolet curing device and an electron beam curing device, the coil coating line further comprising a gloss management tool for managing the gloss of an organic coating formed by applying and curing a wet film of an energy-cured ink on a moving strip in the coil coating line, the gloss management tool comprising: - an adjustment module that defines a defined brightness value Gs of Petition 870250099315, dated 10 / 30 / 2025, page 16 / 125 8 / 49 organic coating and a defined gloss range Rs of the organic coating gloss, - an acquisition module that collects the G-gloss measurement of the organic coating in at least a portion of the width downstream of the electron beam curing device, - a correction module that corrects a deviation of the measured brightness G beyond the defined brightness range Rs, the correction comprising a sub-step of calculating the correction CP to be applied to the cooling module power, taking into account Gs and the measured brightness G, with a closed-loop controller and a sub-step of adjusting the coil coating line taking into account the calculated correction CP. [ 012] Other features and advantages of the invention will be described in more detail in the following description. Brief Description of the Figures [ 013] The invention will be better understood by reading the following description, provided for explanatory purposes only and without the intention of being restrictive, with reference to: Figure 1, which is a schematic representation of a coil coating line, Figure 2, which is a flowchart of a first embodiment of the method according to the invention, Figure 3, which is a flowchart of a second embodiment of the method according to the invention, Figure 4, which is a flowchart of a third embodiment of the method according to the invention. Detailed Description of the Invention

[014] It should be noted that spatially relative terms such as upstream, downstream, lower, upper, above, below, before, Petition 870250099315, dated 10 / 30 / 2025, p. 17 / 125 9 / 49 later... as used in this application, they refer to the positions and orientations of the different constituent elements of the coil coating line.

[015] The method according to the invention is intended for strips, such as metal strips. Steel, whether carbon steel or stainless steel, aluminum and copper are examples of metal strips. In particular, steel strips can be bare or coated with a metallic coating on one or both sides of the strip. Examples of possible steels with metallic coating are galvanized steel, steels coated with a zinc alloy comprising 5% by weight of aluminum (Galfan®), steels coated with a zinc alloy comprising 55% by weight of aluminum, about 1.5% by weight of silicon, the remainder consisting of zinc and unavoidable impurities due to processing (Aluzinc®, Galvalume®), steels coated with an aluminum alloy comprising 8 to 11% by weight of silicon and 2 to 4% by weight of iron, the remainder consisting of aluminum and unavoidable impurities due to processing (Alusi®), steels coated with a layer of aluminum (Alupur®), steels coated with a zinc alloy comprising 0,5 to 20% aluminum, 0.5 to 10% magnesium, the remainder consisting of zinc and unavoidable impurities due to processing; steels coated with an alloy comprising aluminum, magnesium, silicon, and possible additional elements, the remainder consisting of zinc and unavoidable impurities due to processing.

[016] The method according to the invention is also intended for energy-cured inks. The term energy-cured inks refers to radiation-curable compositions that are cured, or dried, using short-wavelength ultraviolet (UV) light and / or high-energy electrons from electron beam (EB) sources. They generally comprise liquid monomers and oligomers in which pigments, fillers, additives, and photoinitiators can be dispersed, generally without the need for solvent or water. Petition 870250099315, dated 10 / 30 / 2025, page 18 / 125 10 / 49 Therefore, they are substantially solvent-free. Energy-cured inks preferably comprise acrylate or methacrylate monomers and photoinitiators.

[017] With reference to Figure 1, the coil coating line (1), according to the invention, comprises mainly, sequentially along the path P of the moving strip, an ink applicator (2), a cooling device (3) comprising a cooling module, an ultraviolet curing device (4) and an electron beam curing device (5).

[018] Path P is the path followed by strip S from its entry into the coil coating line to its exit. It has a width and a length. Equipment is positioned along this path to perform operations on the strip.

[019] An ink applicator (2) is a device that applies a wet ink film to one or both sides of a strip with a defined ink thickness. In particular, its purpose is to apply the energy-cured wet ink film. In the context of the invention, the ink applicator technology is not limited.

[020] According to a variant of the invention, the paint applicator (2) is a paint roller applicator. This is an automated machine that applies paint to one or both sides of a strip using rotating rollers. It is designed so that the strip passes through the machine, which applies a layer of paint to one or both sides of the strip. There are several models of paint rollers, depending on the configuration of the coil coating line, the types of paint used, and the types of strips to be coated. The expert in the field will know which model is most suitable for each case. In general terms, the paint roller comprises a paint tray, a steel or ceramic collection roller, and a rubber-coated coating roller. The paint tray Petition 870250099315, dated 10 / 30 / 2025, p. 19 / 125 The 11 / 49 roller is designed to contain, circulate, and preferably heat the ink. The pickup roller can be partially immersed in the ink and can rotate clockwise or counterclockwise to collect the ink and transfer it to the coating roller. The latter then transfers the ink to the strip.

[021] According to another variant of the invention, the ink applicator (2) is a curtain applicator. In this case, an ink curtain is applied to the horizontal strip, normally transverse to the curtain. The ink falls from a height by gravity from a curtain or cascade matrix while the strip is supported on a support roller. This method is capable of achieving high line speeds and multilayer coatings.

[022] Examples of other paint applicators are: knife applicator, dip or meniscus applicator, slot applicator, rod applicator and slide applicator.

[023] The ink is usually applied with the ink applicator across the entire width of the strip. By default, the width of the wet ink film and, consequently, of the organic coating, is equal to the width of the strip.

[024] The paint applicator (2) is preferably equipped with at least one paint heating device suitable for heating and maintaining the paint at a defined temperature. Heating the paint facilitates its application. In the case of a paint roller applicator, the paint heating device may be a pan heater, i.e., a heater positioned inside or around the paint pan. It may also be a temperature-controlled roller, in particular a temperature-controlled pickup roller, possibly in combination with the pan heater. In the case of a curtain applicator, the paint heating device may be a heater positioned upstream of the curtain matrix. It may also be a temperature-controlled support roller, possibly in combination with the heater. Petition 870250099315, dated 10 / 30 / 2025, p. 20 / 125 12 / 49

[025] The paint applicator (2) is preferably equipped with a temperature measuring device to measure the paint temperature and / or the wet film temperature at the paint applicator level. The temperature device may be, for example, a temperature sensor, a pyrometer or a thermal camera.

[026] The coil coating line (1) further comprises a cooling device (3), which comprises a cooling module, positioned along the P path of the moving strip, downstream of the paint applicator (2) and upstream of the ultraviolet (UV) curing device (4). Its purpose is to cool the wet film of the energy-cured paint, particularly when the wet film is applied over a strip that is still hot from the previous step (e.g., oven curing of a primer or electroplating) or when the ambient temperature is high, e.g., in summer. The cooling device further improves the temperature control of the wet paint film before its surface is cured in the ultraviolet curing device, alleviating temperature variations of the wet film entering the ultraviolet curing device, which would otherwise occur as a result of variations in the line.In fact, since the temperature of the strip exiting the ink applicator decreases at a rate that depends on several parameters (strip type, strip width, strip thickness, line speed, ambient temperature, etc.), the temperature of the wet film entering the ultraviolet curing device can vary significantly from time to time, which would impair gloss. Thanks to the cooling device, the temperature of the wet film can be adjusted.

[027] The cooling device is preferably chosen from among a forced air cooler, a water spray cooler, a water-air spray cooler and a cooled roller. In the case of water-based coolers, as the wet film of the energy-cured ink is applied to the top of the strip, the water is preferably placed in contact only with the part Petition 870250099315, dated 10 / 30 / 2025, p. 21 / 125 13 / 49 rear strip. The cooling device is not a water tank.

[028] According to one variant, the cooling device consists of a cooling module that covers the entire width of the P-path of the moving strip. In this case, the wet film is cooled uniformly along its width as it passes (through) the cooling device.

[029] According to another variant, the cooling device (3) comprises a plurality of cooling modules distributed along the width of the path P. In other words, the plurality of cooling modules forms a row substantially parallel to the width of the path P, i.e., perpendicular to the direction of movement of the strip. For clarity, the cooling modules described here are independent of each other and positioned adjacent, but may be physically inseparable. They may be individually controllable parts of a single cooling device.

[030] The cooling modules are preferably chosen from a forced air cooler, a water spray cooler, a water-air spray cooler and a cooled roller.

[031] Thanks to this design, temperature variations across the strip width can be corrected and minimized. Preferably, the temperature variation of the wet film across the strip width at the cooling device outlet is less than 1 °C. This improves the homogeneity of the coating gloss across the strip width.

[032] According to another variant, the cooling device (3) comprises, sequentially along the path of the moving strip, a base cooler covering the entire width of the path P and the plurality of cooling modules described above. The base cooler can be a forced air cooler, a water spray cooler, a water and air spray cooler, and a cooled roll. Thanks to this design, part of the cooling required to achieve the correct temperature of the wet film at the exit of the Petition 870250099315, dated 10 / 30 / 2025, page 22 / 125 14 / 49 cooling device is provided by the base cooler. Each cooling module of the plurality of cooling modules independently provides the remaining part of the cooling and can be adjusted as needed.

[033] The cooling device (3) is preferably positioned above path P, so that the wet film applied to the top of the strip is cooled directly. The cooling device can also be positioned above and below path P to minimize thermal gradients.

[034] The coil coating line (1) further comprises an ultraviolet (UV) curing device (4). The purpose of this equipment is to cure the surface of the wet film of the energy-cured ink. It has been observed that this surface curing generates a very fine texture on the surface of the film which, combined with coupling agents and possible other fillers, contributes to the gloss of the organic coating after complete curing of the wet film by the electron beam.

[035] According to one variant, the ultraviolet curing device (4) covers the entire width of the P path of the moving strip. In this case, the wet film surface is cured uniformly along the width of the strip when exposed to UV radiation.

[036] According to another variant, the ultraviolet curing device (4) comprises a plurality of UV modules distributed along the path width P. In other words, the plurality of UV modules forms a row substantially parallel to the path width P, i.e., perpendicular to the direction of movement of the strip. For clarity, the UV modules described here are independent of each other and positioned adjacent, but may be physically inseparable. They may be individually controllable parts of a single ultraviolet curing device. Petition 870250099315, dated 10 / 30 / 2025, page 23 / 125 15 / 49

[037] Thanks to this design, different portions of the path / strip width can be exposed to different UV doses. This helps to correct and minimize brightness variations across the strip width. Consequently, the cooling device preferably comprises a plurality of cooling modules forming a row substantially parallel to the path width P, each cooling module being suitable for cooling a portion of the strip width, which is then exposed to UV radiation from a UV module. In other words, each portion of the width covered by a given UV module corresponds to the portion of the width covered by a corresponding cooling module.

[038] UVA and UVB are preferable. UVA is long-range UV radiation, between 320 and 400 nm. UVB is short-wave UV radiation, between 280 and 320 nm. They can be obtained with conventional UV arc lamps.

[039] The ultraviolet curing device (4) is preferably mobile along the P path of the moving strip. It allows the length between the ultraviolet curing device and the EB curing device to be adjusted, i.e., extended or shortened. In fact, it has been observed that surface wrinkles or roughness initiated during UV curing develop further during the time interval between UV curing and EB curing, which affects the gloss of the organic coating.

[040] In the case of a plurality of UV modules, each UV module is preferentially mobile along path P, independently of the others.

[041] The coil coating line (1) further comprises an electron beam curing device (5). The purpose of this equipment is to cure the wet film of the energy-cured ink, i.e., in its full thickness. It also freezes the surface roughness that appears on the surface of the wet film during UV curing and that develops further during the interval of Petition 870250099315, dated 10 / 30 / 2025, p. 24 / 125 16 / 49 time between UV curing and EB curing. The EB device is generally operated under the following conditions: 100-200 kV, 20-50 kGy, inerting with nitrogen below 200 ppm O2.

[042] Preferably, the coil coating line (1) further comprises a wet film temperature measuring device (6) positioned downstream of the cooling device (3) and upstream of the ultraviolet curing device (4). This wet film temperature measuring device measures the wet film temperature before it enters the ultraviolet curing device. It can measure the wet film temperature along the entire width of the moving strip path P or it can measure the temperature in only a portion of the width. Examples of wet film temperature measuring devices are pyrometers, thermal cameras, and thermocouples. The measured temperature can be expressed in °C, °F, or K.

[043] In the case where the wet film temperature measuring device measures the temperature in only a part of the width, the measurement in that part can be considered relevant enough to control the brightness of the entire width of the strip.

[044] Alternatively, a plurality of wet film temperature measuring devices is positioned downstream of the cooling device (3) and upstream of the ultraviolet curing device, so that the entire path width P of the moving strip is covered. They form a row substantially parallel to the path width P. Consequently, the cooling device preferably comprises a plurality of cooling modules forming a row substantially parallel to the path width P, each cooling module being suitable for cooling a portion of the strip width whose temperature is then measured by a wet film temperature measuring device.

[045] To further increase temperature control of Petition 870250099315, dated 10 / 30 / 2025, page 25 / 125 17 / 49 wet film in the ultraviolet curing device, the wet film temperature measuring device (6) and the ultraviolet curing device (4) must not be separated by more than 2 meters, preferably not more than 1 meter, or the wet film temperature must not be measured for more than 4 seconds before curing the wet film in the ultraviolet curing device, preferably not more than 2 seconds. Alternatively, or additionally, the portion of the P path of the moving strip between the wet film temperature measuring device and the ultraviolet curing device may be thermally insulated to maintain the wet film at the measured temperature before being cured in the ultraviolet curing device.

[046] The coil coating line (1) further comprises a gloss measuring device (7) positioned downstream of the electron beam curing device (5). This gloss measuring device measures the gloss of the organic coating after EB curing. It can measure the gloss of the organic coating along the entire width of the moving strip path P or it can measure the gloss in only a part of the width. Examples of gloss measuring devices are gloss meters. The measured gloss is preferably expressed in GU (Gloss Units). The gloss is preferably measured in accordance with ISO 2813:2014 and EN 13523-2:2021 standards. Preferably, the gloss is measured with a geometry of 20°, 60° or 85°, i.e., the reflection angle is 20°, 60° or 85°. More preferably, the gloss is measured with a geometry of 60°.

[047] In the case where the brightness measuring device measures brightness in only a part of the width, the measurement in that part can be considered relevant enough to manage the brightness of the entire width of the strip.

[048] Alternatively, a plurality of brightness measuring devices is positioned downstream of the EB curing device so that Petition 870250099315, dated 10 / 30 / 2025, page 26 / 125 18 / 49 that the entire width of the path P of the moving strip is covered. They form a row substantially parallel to the width of the path P. Consequently, the cooling device preferably comprises a plurality of cooling modules forming a row substantially parallel to the width of the path P, each cooling module being suitable for cooling a portion of the width of the strip, whose brightness is then measured by a brightness measuring device. Consequently, the ultraviolet curing device preferably comprises a plurality of UV modules forming a row substantially parallel to the width of the path P, each UV module being suitable for exposing a portion of the width of the strip to UV radiation, whose brightness is then measured by a brightness measuring device.

[049] The coil coating line (1) is preferably equipped with a strip speed measuring device, more preferably positioned at the level of a guide roller. An example of a strip speed measuring device is a tachometer integrated into the roller shaft.

[050] The coil coating line (1) may further comprise an inductor (8) upstream of the paint applicator (2). It may heat the strip before it reaches the paint applicator. Having a heated strip in the paint applicator favors paint application. Furthermore, the temperature reached by the strip in the inductor may be adjusted to correct possible gloss deviations, as will be described in detail later.

[051] The coil coating line (1) may further comprise an entry section with an unwinder (9) for unwinding the strip to be coated onto the line. The unwinder may be combined with a welding machine or a sewing machine, so that the front end of the strip to be coated can be fixed to the rear end of the strip. Petition 870250099315, dated 10 / 30 / 2025, p. 27 / 125 19 / 49 previous.

[052] Alternatively, the coil coating line can be coupled to a galvanizing line, so that the strip coated with the metal alloys contained in the galvanizing line bath is directly coated with the organic coating, without the need to first wind it up and then unwind it.

[053] The coil coating line (1) may further comprise an input accumulator (10) located in the line's input section, downstream of the uncoiler, if applicable. The accumulator is equipment that accumulates a certain quantity of strip. This is a set of upper and lower banks of rollers, through which the metal strip is threaded in a serpentine shape, and stores pieces of metal as the two banks of rollers move apart. The total length of stored metal depends on the line's design speed, generally 60 seconds of steady-state metal processing time. When the input section of the coil coating line stops, the roller banks move towards each other, and the metal stored in the accumulator continues to feed the remainder of the coil coating line.

[054] The coil coating line (1) may further comprise a cleaning section (11), positioned downstream of the inlet section, in particular downstream of the inlet accumulator, if applicable. In this section, the strip is subjected to a surface preparation step. This type of preparation comprises at least one step selected from rinsing, degreasing and a conversion treatment. The aim of rinsing is to remove loose dirt particles, possible residues of conversion solutions, soaps that may have formed and to obtain a clean and reactive surface. The aim of degreasing is to clean the surface, removing all traces of organic dirt, metallic particles and dust from Petition 870250099315, dated 10 / 30 / 2025, page 28 / 125 20 / 49 surface. Preferably, degreasing is carried out in an alkaline environment. The conversion treatment includes applying a conversion solution to the strip that reacts chemically with the surface, enabling the formation of a conversion layer. This layer increases paint adhesion and corrosion resistance. The conversion treatment is preferably an acidic solution that does not contain chromium. More preferably, the conversion treatment is based on hexafluorotitanic acid or hexafluorozirconic acid.

[055] The coil coating line (1) may further comprise a primer section, upstream of the paint applicator (2) and downstream of the cleaning section, if applicable. In this section, a first coat of paint may be applied over the strip to form a primer coating. The primer section may include a primer paint applicator and curing equipment. Depending on the nature of the primer, the curing equipment may be an oven, such as a convection oven, an infrared (or near-infrared) oven or an induction oven, an ultraviolet curing device and / or an EB curing device.

[056] The coil coating line (1) may further comprise an output accumulator (12) located in the line's output section, downstream of the EB curing device. The output accumulator is similar to the input accumulator described above.

[057] The coil coating line (1) may further comprise a rewinder (13) for rewinding the strip that has been coated on the line. The rewinder may be combined with a cutter to separate the strip from the next one processed on the line.

[058] The coil coating line (1) may further comprise a heating device, positioned along the path P of the moving strip, adjacent to the cooling device. The heating device may be positioned upstream or downstream of the device. Petition 870250099315, dated 10 / 30 / 2025, p. 29 / 125 21 / 49 Cooling. Its purpose is to replace the cooling device when the wet paint film is not hot enough before its surface is cured in the ultraviolet curing device, even if the cooling device is at minimum or switched off. Thanks to the heating device, the temperature of the wet film can be adjusted more precisely than with the cooling device alone.

[059] The heating device is preferably chosen from among an infrared heater, an induction heater, a convector, a forced-air heater, a water spray heater, a water-air mist spray heater, and a heated roller. Preferably, the heating device is an infrared heater. In the case of water-based heaters, as the wet film of energy-cured ink is applied to the top of the strip, the water is preferably placed in contact only with the back of the strip.

[060] According to one variant, the heating device consists of a heating module that covers the entire width of the P-path of the moving strip. In this case, the wet film is heated uniformly along its width as it passes (through) the heating device.

[061] According to another variant, the heating device comprises a plurality of heating modules distributed along the width of the path P. In other words, the plurality of heating modules forms a row substantially parallel to the width of the path P, i.e., perpendicular to the direction of movement of the strip. For clarity, the heating modules described here are independent of each other and positioned adjacent, but may be physically inseparable. They may be individually controllable parts of a single heating device.

[062] Heating modules are preferably chosen from among an infrared heater, an induction heater, a Petition 870250099315, dated 10 / 30 / 2025, page 30 / 125 22 / 49 convector, a forced-air heater, a water spray heater, a water-air spray heater, and a portion of the width of a heated roller. More preferably, the heating modules are infrared heaters.

[063] Thanks to this design, temperature variations across the strip width can be corrected and minimized. Preferably, the temperature variation of the wet film across the strip width at the heating device outlet is less than 1 °C. This improves the homogeneity of the coating gloss across the strip width.

[064] According to another variant, the heating device comprises, sequentially along the path of the moving track, a base heater that covers the entire width of the path P and the plurality of heating modules described above. Thanks to this design, part of the energy required to achieve the correct wet film temperature at the outlet of the heating device is supplied by the base heater. Each heating module of the plurality of heating modules independently supplies the remaining part of the energy and can adjust it as needed.

[065] The heating device is preferably positioned above path P, so that the wet film applied to the upper part of the strip is heated directly. The heating device can also be positioned above and below path P to minimize thermal gradients.

[066] The invention also relates to a gloss management tool for managing the gloss of an organic coating formed by applying and curing a wet film of energy-cured ink on a moving strip in a coil coating line (1), comprising, sequentially along the path P of the moving strip S, an ink applicator (2), a cooling device (3) comprising a module of Petition 870250099315, dated 10 / 30 / 2025, page 31 / 125 23 / 49 cooling, an ultraviolet curing device (4) and an electron beam curing device (5).

[067] The gloss management tool comprises an adjustment module to define a defined gloss value Gs for the organic coating and a defined gloss range Rs for the gloss of the organic coating.

[068] The gloss management tool further comprises an acquisition module configured to collect the gloss measurement G of the organic coating in at least a portion of the width downstream of the electron beam curing device. Preferably, the acquisition module is further configured to collect the temperature measurement T of the wet film in at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device.

[069] The brightness management tool further comprises a correction module configured to correct a deviation of the measured brightness G beyond the defined brightness range Rs, the correction comprising a sub-step of calculating the correction CP to be applied to the cooling module power, taking into account Gs and the measured brightness G, with a closed-loop controller and a sub-step of adjusting a coil coating line configuration, taking into account the calculated correction CP.

[070] The brightness management tool may include a processing unit consisting, for example, of a memory and a processor coupled to the memory. The electronic monitoring device may also include a display screen and input / output means, such as a keyboard and a mouse, each connected to the processing unit. Each configuration module, acquisition module, and correction module may be implemented as executable software by the processor.

[071] The coil coating line is preferably equipped with a gloss management tool to facilitate the Petition 870250099315, dated 10 / 30 / 2025, page 32 / 125 24 / 49 gloss management on the coil coating line.

[072] From a process standpoint, gloss management of an organic coating formed by applying and curing a wet film of energy-cured ink on a moving strip in the coil coating line described above is primarily based on the finding that the wet film temperature before UV curing is critical. In particular, the inventors observed that, in double curing for coil coating, there is a relationship between the wet film temperature before UV curing and the gloss of the organic coating after EB curing. Consequently, any deviation in gloss after EB curing can be efficiently and reproducibly corrected by adjusting the power of the cooling module and, therefore, the wet film temperature before UV curing.

[073] The method is applied to a moving strip. The strip may be a single coil unwound at the entrance of the coil coating line. More generally, the strip is composed of different coils connected to each other end-to-end. The coils form an essentially continuous strip, whose characteristics and technical specifications to be achieved at the exit of the coil coating line vary over time. The strip is moved along the P-path of the coil coating line so that the wet film of energy-cured ink is applied, preferably cooled, and double-cured. In particular, the strip is moved along the P-path of the coil coating line so that the wet film of energy-cured ink is first applied to the strip by the ink applicator, then cooled by the cooling module, exposed to UV radiation in the ultraviolet curing device, and finally cured in the electron beam device.Optionally, the strip can be preheated with an inductor (8) positioned upstream of the ink applicator (2). Optionally, the energy-cured ink can be heated in the ink applicator. Petition 870250099315, dated 10 / 30 / 2025, page 33 / 125 25 / 49

[074] A first embodiment of the method is described with reference to Figure 2.

[075] The first step (100) of the method for brightness management is the definition of some values ​​necessary for correct adjustment.

[076] The gloss value Gs of the organic coating is initially defined. This value corresponds to the gloss requested by the customer or the coil coating line operator. From a practical point of view, it can be entered manually in the gloss management tool, in particular in the configuration module. Alternatively, it can be obtained automatically from the coil coating line order book, in particular in the scheduling tool.

[077] Since small deviations in gloss along the length of the strip are generally acceptable from a quality standpoint, a defined gloss range Rs of the organic coating gloss is also defined. It can be entered as a range proper, with a minimum and a maximum gloss, or it can be entered as a standard deviation of the defined gloss value Gs. Obviously, if, for some reason, small deviations need to be avoided, the defined gloss value Gs can be entered as the minimum and maximum gloss, or the standard deviation can be set to zero. From a practical standpoint, the defined gloss range Rs can be entered manually in the gloss management tool, in particular in the configuration module. Alternatively, it can be obtained automatically in the coil coating line management tool or in the coil coating line order book, in particular in the scheduling tool.The defined gloss range Rs of the gloss can also be obtained from standards such as EN10169: 2013.

[078] In a second stage (120) of the method for gloss management, the gloss G measurement of the organic coating in hair Petition 870250099315, dated 10 / 30 / 2025, page 34 / 125 26 / 49 minus a downstream width portion of the electron beam curing device is collected.

[079] Preferably, the wet film temperature T measurement is also collected on at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device. More preferably, the temperature is measured with a wet film temperature measuring device as described above, and the gloss is measured with a gloss measuring device as described above.

[080] Preferably, the measurement is taken at time intervals short enough to allow for adequate brightness management. Examples of time intervals are: less than 30 s, less than 20 s, less than 10 s, less than 5 s, less than 2 s, less than 2 seconds. More preferably, the measurement is substantially continuous or continuous. Preferably, the measurement is collected at time intervals short enough to allow for adequate brightness management. Examples of time intervals are: less than 10 s, less than 5 s, less than 2 s, less than 2 seconds. More preferably, the measurement is collected substantially continuously or continuous. Preferably, the measurements are collected in the brightness management tool, in particular in the acquisition module, more preferably automatically with the appropriate interface.

[081] By width portion, it is understood that the moving strip is conceptually divided into adjacent portions across the width of the strip. There may be a single width portion or several. Consequently, the wet film and the organic coating may also be conceptually divided into the same width portions. By at least one width portion, it is understood that the method is implemented on one width portion, on several width portions, or across the entire width of the moving strip. If it is not implemented across the entire width, it is possible to measure and collect: Petition 870250099315, dated 10 / 30 / 2025, page 35 / 125 27 / 49 - the glossiness G of the organic coating in a single width portion, if the measurement in that width portion is considered relevant enough to manage the glossiness of the entire width of the strip, or - the glossiness of the organic coating in various width portions, so that the glossiness in each width portion can be managed independently of the other portions.

[082] Similarly, it is optionally possible to measure and collect: - the temperature T of the wet film in a single width portion, if the measurement in that width portion is considered sufficiently representative of the average temperature across the entire width of the strip or, - the temperatures of the wet film in a plurality of width portions, so that the temperature in each width portion can be adjusted independently of the other portions.

[083] In one variant, the collection step is performed after the adjustment step.

[084] In another variant, particularly during continuous operation of the coil coating line, the take-up step can be performed in parallel with the adjustment step. In this case of continuous operation, as the strip is composed of different coils connected to each other end-to-end, changes in the strip characteristics and technical specifications frequently occur. While the take-up step is in progress, any of the defined parameters, in particular any of the defined gloss values ​​Gs and / or the defined gloss range Rs, may have to be modified for some reason, such as a change in the specified gloss or a change in the energy-cured ink. Consequently, the adjustment step is performed.

[085] Preferably, in this second stage (120) of the brightness management method, the PW power of the cooling module is also Petition 870250099315, dated 10 / 30 / 2025, page 36 / 125 28 / 49 collected.

[086] In a third step (130) of the brightness management method, a possible deviation of the measured brightness G beyond the defined brightness range Rs is corrected. First, a possible brightness deviation is evaluated by comparing the measured brightness G with the defined brightness value Gs and / or with the defined brightness range Rs. If the measured brightness G is still within the defined brightness range Rs, the settings are maintained. If the measured brightness G has deviated beyond the defined brightness range Rs, the CP correction to be applied to the cooling module power is calculated, taking into account Gs and the measured brightness G, with a closed-loop controller.

[087] The assessment of brightness deviation can be done at any time. Preferably, it is done at time intervals short enough for adequate brightness management. Examples of time intervals are: less than 30 s, less than 20 s, less than 10 s, less than 5 s, less than 2 and less than 2 seconds. More preferably, the assessment is substantially continuous or continuous.

[088] The calculation of the CP correction to be applied to the cooling module power is performed with a closed-loop controller. Preferably, this controller is a proportional-integral-derivative controller. Since, in some cases, only one or two terms of the controller may provide adequate control, some controller parameters may be zeroed to disable some terms. In particular, at least one of the integral and derivative terms of the proportional-integral-derivative controller is active. By active, it is understood that the term is not zeroed / that it is used for the calculation. In other words, the proportional-integral-derivative controller is preferably a PI controller, a PD controller, an I controller, a D controller, or a PID controller.

[089] Thus, the CP correction can be remarkably calculated. Petition 870250099315, dated 10 / 30 / 2025, page 37 / 125 29 / 49 according to a general formula equation: CP(t) = Kpe(t) + Ktj0te(r)dr + Kd^· (7) or CP(t) = Kp(e(t)+ -1 £β(τ)άτ + Τά^) (8) ![ wt where e is the error, i.e., the difference between a desired setpoint and a measured process variable, t is the time or instantaneous time, and τ is the integration variable. Other control functions are well known to experts in the field and can be used to control the gloss of the organic coating.

[090] In a first variant of the CP correction calculation, the closed-loop control is based directly on the gloss of the organic coating. In other words, the measured process variable is the measured gloss and the desired setpoint is Gs. In this case, the CP correction is a function of the difference between Gs and the measured gloss G.

[091] In particular, the CP correction to be applied to the cooling module power can be calculated according to equation 1: CP(t) = Kpei(t) + KtJ0 e 1 (τ)άτ + Kd^ (1) where Kp is the proportional gain, Ki is the integral gain, Kd is the derivative gain and e1 is the difference between Gs and the measured brightness G.

[092] In particular, Ki > 0 and / or Kd > 0.

[093] The rules of good practice for the initial selections of Kp, Ki and Kd and their adjustment are well known to experts in the field. Kp, Ki and Kd can therefore be easily selected and adjusted as needed. The initial gains Kp, Ki and Kd can be entered manually in the brightness management tool, in particular in the configuration module. They can be set during the configuration step.

[094] Alternatively, the CP correction to be applied to Petition 870250099315, dated 10 / 30 / 2025, page 38 / 125 The 30 / 49 cooling module power can be calculated according to the following equation: CP(t) = Kp(e , (t) +1£e,(τ)άτ + Td) (9) ij LvL where Kp is the proportional gain, Ti is the integration time, Td is the derivation time and e1 is the difference between Gs and the measured brightness G.

[095] In particular, 1 / Ti > 0 and / or Td > 0.

[096] The rules of good practice for the initial selections of Kp, Ti and Td and their adjustment are well known to experts in the field. Kp, Ti and Td can therefore be easily selected and adjusted as needed. The initial terms Kp, Ti and Td can be entered manually into the brightness management tool, in particular in the configuration module. They can be set during the configuration step.

[097] In a second variant, where the collection step also includes collecting the temperature measurement T of the wet film in at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device, as it was observed that there is a relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after EB curing, the closed-loop control of the cooling module power is based on the temperature of the wet film in at least a portion of the width downstream of the cooling module and upstream of the ultraviolet curing device. In other words, the measured process variable is the measured temperature and the desired setpoint is the corrected temperature Tc to be reached by the wet film, in at least a portion of the width downstream of the cooling module and upstream of the ultraviolet curing device, to obtain the defined gloss value Gs.

[098] Thus, in a first sub-step of the correction step, the corrected temperature Tc to be reached by the wet film in the portion is calculated Petition 870250099315, dated 10 / 30 / 2025, page 39 / 125 31 / 49 of at least one width downstream of the cooling module and upstream of the ultraviolet curing device.

[099] In general, the corrected temperature Tc is calculated according to equation 2: Tc = f1 (T, G, Gs) (2) where the function f1 is a predefined mathematical relationship between the wet film temperature before Ultraviolet curing and the gloss of the organic coating after Electron Beam curing. By predefined, it is understood that a calibration step, preferably as described below, was performed before implementing the method on the coil coating line.

[0100] The function f1 can be obtained in a calibration step performed before the configuration step. During this calibration step, wet films of the energy-cured ink to be used in the coil coating line are heated to different temperatures, double-cured under standard curing conditions, and the gloss of the organic coatings is measured. The function f1 can therefore be deduced. This calibration step can be performed once and does not need to be performed every time the method according to the invention is implemented. The function f1 can be manually entered into the gloss management tool, in particular in the configuration module.Alternatively, it can be obtained automatically by cross-referencing the predefined mathematical relationships entered in the gloss management tool, possibly in the form of a table, with the ink reference from the coil coating line order book, specifically in the scheduling tool. The f1 function can be defined during the setup step.

[0101] In particular, it has been observed that, for some commercially available energy-cured paints for coating steel coils, Petition 870250099315, dated 10 / 30 / 2025, page 40 / 125 32 / 49 There is a linear mathematical relationship between the temperature of the wet film before ultraviolet curing and the gloss of the organic coating after electron beam curing, as expressed by the following equation: T = T0 - KG (10) Where K is the constant of proportionality.

[0102] In this case, the corrected temperature Tc is calculated according to equation 3: Tc = T + K (G - Gs) (3)

[0103] The proportionality constant K can be obtained in a calibration step performed before the setting step. During this calibration step, wet films of the energy-cured ink to be used in the coil coating line are heated to different temperatures, double-cured under standard curing conditions, and the gloss of the organic coatings is measured. The proportionality constant K can therefore be deduced. It is preferably expressed in °C / GU, °F / GU, or K / GU, depending on the temperature unit. This calibration step can be performed once and does not need to be performed every time the method according to the invention is implemented.

[0104] From a practical point of view, during the correction step, the proportionality constant K is obtained from a predefined linear mathematical relationship between the wet film temperature before ultraviolet curing and the gloss of the organic coating after electron beam curing, with the predefined linear mathematical relationship available to the coil coating line operator. By predefined, it is understood that a calibration step, preferably as described above, has been performed before the implementation of the method on the coil coating line. The proportionality constant K can be manually entered into the gloss management tool, in particular in the module of Petition 870250099315, dated 10 / 30 / 2025, page 41 / 125 33 / 49 configuration. Alternatively, it can be obtained automatically by cross-referencing the predefined linear mathematical relationships entered in the gloss management tool, possibly in the form of a table, with the ink reference from the coil coating line order book, in particular in the scheduling tool.

[0105] For example, it has been observed that, for some commercially available energy-cured paints for coating steel coils, K is generally between 0.3 and 1.2. More generally, K > 0.

[0106] Once the corrected temperature Tc has been calculated, the correction CP to be applied to the cooling module power is calculated as a function of the difference between Tc and the measured temperature T.

[0107] In particular, in the case of a proportional-integral-derivative controller in parallel form, the CP correction can be calculated according to equation 4: CP(t) = K'pe2(t) + K'tJ0 β2(τ)άτ + K'di-~- (4) where K'p is the proportional gain, K'i is the integral gain, K'd is the derivative gain and e2 is the difference between Tc and the measured temperature T.

[0108] In particular, K'i > 0 and / or K'd > 0.

[0109] The rules of good practice for the initial selections of K'p, K'i and K'd and their adjustment are well known to experts in the field. K'p, K'i and K'd can therefore be easily selected and adjusted as needed. The initial gains K'p, K'i and K'd can be entered manually in the brightness management tool, in particular in the configuration module. They can be set during the configuration step.

[0110] Alternatively, in the case of a proportional-integral-derivative controller in standard form, the CP correction to be applied to the cooling module power can be calculated according to the Petition 870250099315, dated 10 / 30 / 2025, page 42 / 125 34 / 49 following equation: CP(t) = K1pfa(t) +1 tf e2(τ)άτ + T'd^~-) (11) where K'p is the proportional gain, T'i is the integration time, T'd is the derivation time and e2 is the difference between Tc and the measured temperature T.

[0111] In particular, 1 / T'i > 0 and / or T'd > 0.

[0112] The best practice rules for the initial selections of K'p, T'i and T'd and their adjustment are well known to experts in the field. K'p, T'i and T'd can therefore be easily selected and adjusted as needed. The initial terms K'p, T'i and T'd can be entered manually into the brightness management tool, in particular in the configuration module. They can be set during the configuration step.

[0113] This second variant of the CP correction calculation is very convenient for avoiding the juxtaposition of interdependent closed-loop controls and for controlling that the wet film temperature does not fall below a minimum temperature Tmin, which would prevent the energy-cured ink from reacting when exposed to UV radiation, as will be described in detail later.

[0114] After calculating the correction CP to be applied to the cooling module power, a line configuration is adjusted taking into account the correction CP, so that the measured brightness deviation is corrected.

[0115] In particular, after the correction CP calculation, the cooling module power is adjusted by the correction CP. Adjusting the cooling module power includes switching it on or off. Thanks to the adjustment of the cooling module, the wet film temperature in the width portion downstream of the cooling module and upstream of the ultraviolet curing device is corrected, and a gloss value of Gs is obtained in the organic coating. Petition 870250099315, dated 10 / 30 / 2025, page 43 / 125 35 / 49 in the downstream width portion of the electron beam curing device. The cooling module power adjustment can be done manually by an operator or automatically with the aid of the gloss management tool, in particular the correction module.

[0116] Alternatively, in the case where the coil coating line is equipped with a heating device consisting of a heating module and adjacent to the cooling device, once the Cp correction has been calculated, the heating module is switched on and its power is adjusted so that the brightness value Gs is obtained in the organic coating in at least a portion of the width of the moving stream downstream of the electron beam curing device. If the corrected temperature Tc has been calculated before the calculation of the Cp correction, the power of the heating module is adjusted so that the wet film reaches the corrected temperature Tc in at least a portion of the width of the moving strip downstream of the cooling module / heating module and upstream of the ultraviolet curing device.This alternative method of correcting gloss is particularly useful when the cooling module is already at minimum capacity or switched off, and the temperature of the wet film upstream of the ultraviolet curing device needs to be increased even further.

[0117] Alternatively, if the coil coating line is equipped with an inductor upstream of the paint applicator, once the Cp correction has been calculated, the inductor power is adjusted so that the strip temperature at the paint applicator level is adjusted so that the gloss value Gs is obtained in the organic coating in at least a portion of the width of the moving current downstream of the electron beam curing device. If the corrected temperature Tc has been calculated before the Cp correction calculation, the inductor power is adjusted so that the wet film reaches the corrected temperature Tc in at least a portion of the Petition 870250099315, dated 10 / 30 / 2025, page 44 / 125 36 / 49 width of the moving strip downstream of the cooling / heating module and upstream of the ultraviolet curing device. This alternative way of correcting gloss is particularly useful when the cooling module is already at minimum capacity or switched off and the temperature of the wet film upstream of the ultraviolet curing device needs to be increased further.

[0118] In one variant, the correction step (130) is performed after the collection step (120).

[0119] In another variant, particularly during continuous operation of the coil coating line, the correction step can be performed in parallel with the collection step. In this case of continuous operation, as the strip is composed of different coils connected to each other end-to-end, changes in the strip's characteristics and technical specifications frequently occur. These changes can cause deviations in gloss. While the collection step is in progress, the correction step is performed to correct the measured gloss.

[0120] Optionally, the method further comprises a step (110) during which the initial line conditions are defined. This step is called the initial line adjustment step. As explained above, the method is such that any deviation of the measured gloss beyond the defined gloss range Rs is corrected. That said, at the start of a production campaign on the coil coating line or after a significant change, for example, in strip format, ink thickness, ink color or line speed, the line conditions may change relative to the appropriate line conditions to achieve the defined gloss value Gs. In this case, the cooling module may not cool adequately and / or may need some time to reach the power corresponding to the correction Cp and / or may not be powerful enough to allow the wet film to reach the Petition 870250099315, dated 10 / 30 / 2025, page 45 / 125 37 / 49 corrected temperature Tc. Consequently, a portion of the coated strip may have to be discarded because the gloss is out of specification. Furthermore, the UV dose to which the wet film must be exposed to initiate surface roughness that will bring the defined gloss value may not be appropriate. In this case, the cooling module needs to compensate for the altered UV dose, possibly by cooling strongly, which takes time. Here again, a portion of the coated strip may have to be discarded because the gloss is out of specification. To minimize the length of coated strip that is out of specification, it is advantageous to define initial line conditions.

[0121] To this end, in a first sub-step, several process parameters and / or specifications of the coated strip are collected. An example of a process parameter is the initial line speed LS0. Preferably, this is the speed recommended for the next coil to be coated on the coil coating line. Another example is the initial thickness FTh0 of the wet film applied to the strip by the ink applicator. The initial film thickness is preferably that which corresponds to the thickness of the organic coating specified for the next coil to be coated on the coil coating line. Another example is the temperature of the moving strip before the ink applicator, preferably before the inductor. Examples of specifications are the initial strip thickness STh0, the initial strip width SWd0, and the ink color.Ideally, the initial line speed LS0, initial thickness FTh0, initial strip thickness STh0, initial strip width SWd0, and ink color are collected. From a practical standpoint, the process parameters and / or specifications can be manually entered into the gloss management tool, particularly in the configuration module. Alternatively, they can be automatically obtained from the order book of the coil coating line, particularly from the scheduling tool, and / or deduced from the order book. For example, the initial film thickness FTh0. Petition 870250099315, dated 10 / 30 / 2025, page 46 / 125 38 / 49 can be deduced from the thickness of the organic coating specified in the order book.

[0122] Once the process parameters and / or specifications have been collected, in a second sub-step, the initial line conditions are defined taking into account the collected process parameters and / or specifications. In particular, they are calculated from the collected process parameters and / or specifications. The following initial line conditions can be defined: - the initial power PW0 of the cooling module, - the initial UV dose D0 of the ultraviolet curing device, or UV module, if applicable, - the initial length L0 between the ultraviolet curing device, or the UV module if applicable, and the electron beam curing device.

[0123] The initial power PW0 can be defined by knowing the mass flow rate of the moving strip, the specific heat of the strip, and the cooling efficiency. The initial UV dose D0 can be defined based on data obtained in a calibration step performed before the initial line setup step. The initial length L0 can be defined based on data obtained in a calibration step performed before the initial line setup step.

[0124] From a practical standpoint, the initial line conditions can be manually entered into the coil coating line management tool. Alternatively, they can be automatically injected by the gloss management tool into the coil coating line management tool.

[0125] In one variant, the initial line definition step (110) is performed before the definition step (100). It assists in the start of production. Petition 870250099315, dated 10 / 30 / 2025, page 47 / 125 39 / 49 with line conditions already optimized for the first reel of the production campaign, in addition to an initial combination of the defined gloss value Gs and the defined gloss range Rs. During production, the collection step and the correction step can be performed to manage the gloss. When any of the defined parameters, in particular any of the defined gloss values ​​Gs and / or the defined gloss range Rs, needs to be modified for some reason, such as a change in the specified gloss or a change in the energy-cured ink, the performance of the collection step (120) and the correction step (130) is relied upon to maintain the measured gloss within the defined gloss range Rs.

[0126] In another variant, the initial line definition step (110) is performed after the definition step (100), as illustrated in Figure 2. In this way, the configuration of the initial line conditions can be done taking into account the defined brightness value Gs. The line conditions are therefore better optimized for the first reel of the production campaign. Furthermore, during production, when any of the defined parameters, in particular any of the defined brightness values ​​Gs and / or the defined brightness range Rs, needs to be modified for any reason, the initial line settings can be reset to help minimize the transition period.

[0127] In another variant, the initial line definition step (110) is performed before and after the definition step (100) to take advantage of both variants described above.

[0128] In another variant, particularly during continuous operation of the coil coating line, the initial line setup step can be performed in parallel with the take-up step. In this case of continuous operation, since the strip is composed of different coils connected to each other end-to-end, changes in the strip characteristics and technical specifications frequently occur. The reset of Petition 870250099315, dated 10 / 30 / 2025, page 48 / 125 40 / 49 line conditions when one of these changes occurs helps to achieve the defined brightness value as quickly as possible.

[0129] A second embodiment of the method is now described with reference to Figure 3.

[0130] This method differs primarily from the first, as the correction stage includes additional sub-stages for: - ensure that the temperature of the wet film upstream of the ultraviolet curing device does not fall below a minimum temperature Tmin that would block diffusion and / or mobility phenomena, and - Correct the deviation of the measured brightness G accordingly.

[0131] Thanks to this configuration, it is more guaranteed that the wet film will react properly to UV exposure.

[0132] The details provided in the description of the first modality apply to the second modality. The additional steps and corresponding resources are described in detail below.

[0133] The definition step (100) also includes setting a minimum temperature Tmin for the energy-cured ink. This temperature may be the one recommended by the ink supplier. Alternatively, it may be identified during a calibration step performed before the configuration step. During this calibration step, wet films of the energy-cured ink to be used in the roll coating line are cooled to different temperatures, double-cured under standard curing conditions, and the gloss of the organic coatings is measured. The temperature at which the wet film does not react to UV exposure can be set as Tmin. From a practical point of view, the minimum temperature Tmin can be entered manually in the gloss management tool, in particular in the configuration module. Alternatively, it can be obtained automatically by cross-referencing the different minimum temperatures entered in the Petition 870250099315, dated 10 / 30 / 2025, page 49 / 125 41 / 49 gloss management tool with ink reference from the coil coating line order book, particularly in the scheduling tool.

[0134] The collection step (120) comprises collecting the temperature measurement T of the wet film in at least one portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device.

[0135] The collection stage (120) also includes collecting the UV dose D from the UV module. The power of the UV module is generally known to the operator, possibly by the roll coating line management tool, but, for a given power, the actual UV dose to which the wet film is exposed varies with the LS line speed. Consequently, the UV dose is calculated based on the power of the UV module and the line speed and collected. The line speed itself is generally known to the operator, possibly by the roll coating line management tool.

[0136] Preferably, the UV dose is recalculated and collected each time the UV module power and / or line speed are adjusted. More preferably, the UV dose collection is substantially continuous. Preferably, the UV dose is collected in the brightness management tool, in particular in the acquisition module, more preferably automatically with the appropriate interface.

[0137] During the correction step (130), if the corrected temperature Tc has been calculated before the calculation of the correction Cp, it is compared with the minimum temperature Tmin. Otherwise, the correction step may include a sub-step of calculating the corrected temperature Tc to be reached by the wet film, in at least a portion of the width downstream of the cooling module and upstream of the curing device by Petition 870250099315, dated 10 / 30 / 2025, page 50 / 125 42 / 49 ultraviolet. This substep can be performed after calculating the Cp correction or at any other appropriate time. Once this substep is completed, Tc can be compared with the minimum temperature Tmin. Alternatively, T can be compared with the minimum temperature Tmin.

[0138] If Tc (or T) is greater than Tmin, the cooling module power is adjusted as detailed in the first mode.

[0139] If Tc (or T) is less than Tmin, the gloss must be corrected without further increasing the power of the cooling module. One way to do this is to adjust, in particular to decrease, the power of the UV module. In fact, it has been observed that this affects the gloss of the organic coating. The lower the UV dose on the wet film, the higher the gloss. Consequently, the correction step (130) further comprises the calculation of the CD correction to be applied to the UV dose to which the wet film in at least a portion of the width of the moving strip must be exposed in the UV module, according to equation 5: CD = f2 (G, Gs) (5)

[0140] Equation (5) can be obtained in a calibration step performed before the correction step, preferably before the setting step. During this calibration step, wet films of the energy-cured ink to be used in the roll coating line are exposed to different UV doses, cured by EB under standard curing conditions, and the gloss of the organic coating is measured. The function f2 can therefore be deduced for each energy-cured ink. This calibration step can be performed once and does not need to be performed every time the method according to the invention is implemented. Alternatively, the function f2 can be a PID function of the difference between Gs and the measured gloss G.

[0141] Preferably, the function f2 of the predefined mathematical relationship between the UV dose to which the wet film of the energy-cured ink is exposed and the gloss of the organic coating after electron beam curing Petition 870250099315, dated 10 / 30 / 2025, page 51 / 125 43 / 49 is defined during the setting stage. By default, it is understood that a calibration step, preferably as described above, has been performed before the method is implemented on the coil coating line. The f2 function can be manually entered in the gloss management tool, in particular in the configuration module. Alternatively, it can be obtained automatically by cross-referencing the predefined mathematical relationships entered in the gloss management tool with the ink reference from the coil coating line order book, in particular in the programming tool.

[0142] For example, it has been observed that, for commercially available energy-cured paints for coating steel coils, f2 is generally related to a gloss curve that decreases towards an asymptote as the UV dose increases.

[0143] Once the CD correction to be applied to the UV dose has been calculated, a line configuration different from the cooling module power, different from the heating module power, if applicable, and different from the inductor power, if applicable, is adjusted taking into account the calculated CD correction, so that the deviation of the measured brightness is corrected.

[0144] In the variant illustrated in Figure 3, once the CD correction to be applied to the UV dose has been calculated, the UV module power is adjusted, in particular reduced, so that the wet film in at least a portion of the width of the moving strip is exposed to the UV dose Dc = D + CD in the UV module. Thanks to the adjustment of the UV module, the UV dose to which the wet film is exposed in the portion of the width of the UV module is corrected and a brightness of value Gs is obtained in the organic coating in the portion of the width downstream of the electron beam curing device. The adjustment of the UV module power can be done manually by an operator or automatically with the aid of the brightness management tool. Petition 870250099315, dated 10 / 30 / 2025, page 52 / 125 44 / 49

[0145] A third embodiment of the method is now described with reference to Figure 4.

[0146] This method differs primarily from the second one, as the correction stage includes additional sub-stages for: - ensure that the UV dose does not fall below a minimum UV dose Dmin to which the wet film can be exposed, - Correct the deviation of the measured brightness G appropriately.

[0147] Thanks to this configuration, the method further prevents under-curing of the wet film in the ultraviolet curing device, which can impair gloss.

[0148] The details provided in the description of the first and second modes apply to the third mode. The additional steps and corresponding resources are described in detail below.

[0149] In this embodiment, the UV module of the coil coating line ultraviolet curing device is movable along path P. Consequently, the length L between the UV module and the electron beam curing device can be adjusted.

[0150] The definition step (100) also includes adjusting a minimum UV dose Dmin to which the wet film can be exposed in the UV module. This UV dose may be that recommended by the ink supplier. Alternatively, it may be identified by the roll coating line operator, particularly during a calibration step. From a practical point of view, the minimum UV dose Dmin can be entered manually in the gloss management tool, in particular in the configuration module. Alternatively, it can be obtained automatically by cross-referencing the different minimum UV doses entered in the gloss management tool with the ink reference from the roll coating line order book, in particular in the programming tool. Petition 870250099315, dated 10 / 30 / 2025, page 53 / 125 45 / 49

[0151] The collection step (120) further comprises collecting the length L between the UV module and the electron beam curing device. This length is generally known to the operator, possibly by the coil coating line management tool. It can be collected manually. Preferably, it is collected in the gloss management tool, more preferably automatically with the appropriate interface. Preferably, it is collected only when the length L is modified.

[0152] During the correction step (130), once the correction CD to be applied to the UV dose has been calculated, the sum D + CD (referred to below as Dc) is compared with the minimum UV dose Dmin. If Dc is greater than Dmin, the power / setting of the UV module is adjusted so that the wet film in at least a portion of the width of the moving strip is exposed to the UV dose Dc in the UV module. Thanks to the adjustment of the UV module, the UV dose to which the wet film is exposed in the portion of the width of the UV module is corrected and a brightness of value Gs is obtained in the organic coating in the portion of the width downstream of the electron beam curing device, as in the second embodiment.

[0153] If Dc is less than Dmin, the gloss must be corrected without further decreasing the UV dose of the UV module. One way to do this is to adjust, in particular to shorten, the length between the UV module and the electron beam curing device. Indeed, it has been observed that this affects the gloss of the organic coating. The shorter the time between UV curing and EB curing, the greater the gloss. Consequently, the correction step (130) further comprises the calculation of the CL correction to be applied to the length L between the UV module and the electron beam curing device according to equation 6: CL = f3 (G, Gs) (6)

[0154] Equation (6) can be obtained in a calibration step Petition 870250099315, dated 10 / 30 / 2025, page 54 / 125 46 / 49 performed before the correction step, preferably before the setting step. During this calibration step, wet films of the energy-cured ink to be used in the roll coating line are sequentially exposed to UV curing and EB curing under standard curing conditions, with varying times between the two cures, and the gloss of the organic coating is measured. The function f3 can therefore be deduced for each energy-cured ink. This calibration step can be performed once and does not need to be performed every time the method according to the invention is implemented. Alternatively, the function f3 can be a PID function of the difference between Gs and the measured gloss G.

[0155] Preferably, the function f3 of the predefined mathematical relationship between the length between the UV module and the electron beam curing device and the gloss of the organic coating after electron beam curing is defined during the setting step. By predefined, it is understood that a calibration step, preferably as described above, has been performed before the implementation of the method on the coil coating line. The function f3 can be entered manually in the gloss management tool, in particular in the configuration module. Alternatively, it can be obtained automatically by cross-referencing the predefined mathematical relationships entered in the gloss management tool with the ink reference from the coil coating line order book, in particular in the programming tool.

[0156] For example, it has been observed that, for commercially available energy-cured paints for coating steel coils, f3 is generally related to a decreasing gloss curve towards an asymptote as L increases.

[0157] Once the CL correction to be applied to the length between the UV module and the electron beam curing device has been calculated, Petition 870250099315, dated 10 / 30 / 2025, page 55 / 125 47 / 49 a line configuration different from the cooling module power, different from the heating module power, if applicable, different from the inductor power, if applicable, and different from the UV module power is adjusted taking into account the calculated CL correction, so that the measured brightness deviation is corrected.

[0158] In the variant illustrated in Figure 4, once the CL correction is calculated, the length between the UV module and the electron beam curing device is adjusted, in particular shortened, to the corrected length Lc = L + CL, so that the gloss value Gs is obtained on the organic coating in at least a portion of the width of the moving strip downstream of the electron beam curing device. The length adjustment can be done manually by an operator or automatically with the aid of the gloss management tool.

[0159] Alternatively, especially if the length between the UV module and the electron beam curing device cannot be extended or shortened, the line speed can be adjusted. In this case, the initial line configuration can be performed again to adjust the new line speed, the initial power PW0 of the cooling module, the initial UV dose D0 of the ultraviolet curing device, and the initial length L0 between the ultraviolet curing device and the electron beam curing device.

[0160] The invention also relates to a method for forming an organic coating on a moving strip in a coil coating line, comprising, sequentially along path P of the moving strip, an ink applicator, a cooling device comprising a cooling module, an ultraviolet curing device and an electron beam curing device, the method comprising the steps of: - Apply a wet film of energy-cured ink to the moving strip. Petition 870250099315, dated 10 / 30 / 2025, page 56 / 125 48 / 49 with the paint applicator, - Cooling the wet, energy-cured ink film in the cooling module. - Exposing the wet, energy-cured ink film to UV radiation in the ultraviolet curing device, - Curing the wet film of energy-cured ink in the electron beam device to form the organic coating, the gloss of the organic coating being managed by: - Define a gloss value Gs for the organic coating and a gloss range Rs for the organic coating. - collect the G-gloss measurement of the organic coating in at least a portion of the width downstream of the electron beam curing device, - Correcting a deviation of the measured brightness G beyond the defined brightness range Rs, this correction step comprises a sub-step of calculating the correction CP to be applied to the cooling module power, taking into account Gs and the measured brightness G, with a closed-loop controller, and a sub-step of adjusting the coil coating line, taking into account the calculated correction CP.

[0161] All details provided regarding the method for gloss management and all details provided regarding the coil coating line apply to the method for forming the organic coating.

[0162] The invention also relates to a method for manufacturing a pre-painted metal, comprising a metal strip and an organic coating, in a coil coating line comprising, sequentially along the path P of the moving metal strip, a paint applicator, a cooling device comprising a module of Petition 870250099315, dated 10 / 30 / 2025, page 57 / 125 49 / 49 cooling, an ultraviolet curing device and an electron beam curing device, the method comprising the steps of: - Apply a wet film of energy-cured paint to the movable metal strip using the paint applicator. - Cooling the wet, energy-cured ink film in the cooling module. - Exposing the wet, energy-cured ink film to UV radiation in the ultraviolet curing device, - Curing the wet film of energy-cured ink in the electron beam device to form the organic coating, the gloss of the organic coating being managed by: - Define a defined gloss value Gs for the organic coating and a defined gloss range Rs for the gloss of the organic coating. - collect the G-gloss measurement of the organic coating in at least a portion of the width downstream of the electron beam curing device, - To correct a deviation in measured brightness G beyond the defined brightness range Rs, this correction step comprising a sub-step of calculating the correction CP to be applied to the cooling module power, taking into account Gs and the measured brightness G, with a closed-loop controller, and a sub-step of adjusting a coil coating line configuration, taking into account the calculated correction CP.

[0163] Optionally, the metal strip can be heated before applying the wet film of energy-cured paint.

[0164] All details provided regarding the gloss management method and all details provided regarding the coil coating line apply to the pre-painted metal manufacturing method. Petition 870250099315, dated 10 / 30 / 2025, page 58 / 125

Claims

1 / 6 Claims 1. METHOD FOR MANAGING THE GLOSS OF AN ORGANIC COATING formed by applying and curing a wet film of energy-cured ink on a moving strip (S) in a coil coating line (1), comprising, sequentially along the path (P) of the moving strip (S), an ink applicator (2), a cooling device (3) comprising a cooling module, an ultraviolet curing device (4) and an electron beam curing device (5), the method characterized by comprising the steps of: - defining (100) a defined gloss value (Gs) for the organic coating and a defined gloss range (Rs) for the gloss of the organic coating, - collecting (120) the gloss measurement (G) of the organic coating in at least a width portion downstream of the electron beam curing device (5), - correcting (130) a deviation of the measured gloss (G) beyond the defined gloss range (Rs),This correction step comprises a sub-step for calculating the correction (CP) to be applied to the cooling module power, taking into account (Gs) and the measured brightness (G), with a closed-loop controller, and a sub-step for adjusting a coil coating line configuration (1), taking into account the calculated correction (CP).

2. METHOD, according to claim 1, characterized in that the closed-loop controller is a proportional-integral-derivative controller.

3. METHOD, according to any one of claims 1 to 2, characterized in that the correction (CP) is a function of the difference between (Gs) and the measured brightness (G). Petition 870250099315, dated 10 / 30 / 2025, page 59 / 125 2 / 6 4. METHOD, according to any one of claims 1 to 3, characterized in that the correction (CP) to be applied to the cooling module power is calculated according to equation 1: CP(t) = Kpei(t) + Kt J0 ei(τ)άτ + Kd^P (1) where Kp is the proportional gain, Ki is the integral gain, Kd is the derivative gain and e1 is the difference between (Gs) and the measured brightness (G).

5. METHOD, according to any one of claims 1 to 2, characterized in that the collection step (120) further comprises collecting the temperature measurement (T) of the wet film in at least one portion of the width of the moving strip (S) downstream of the cooling module and upstream of the ultraviolet curing device (4), and in that the correction step (130) further comprises a sub-step of calculating the corrected temperature (Tc) to be reached by the wet film, in at least one portion of the width downstream of the cooling module and upstream of the ultraviolet curing device (4).

6. METHOD, according to claim 5, characterized in that the corrected temperature (Tc) is calculated according to equation 2: Tc = f1 (T, G, Gs) (2) wherein the function f1 is a predefined mathematical relationship between the wet film temperature before ultraviolet curing and the gloss of the organic coating after electron beam curing.

7. METHOD, according to claim 5, characterized in that the corrected temperature (Tc) is calculated according to equation 3: Tc = T + K (G - Gs) (3).

8. METHOD, according to any one of claims 5 to 7, characterized in that the correction (CP) is a function of the difference between (Tc) and the measured temperature (T).

9. METHOD, according to any of the claims Petition 870250099315, of 10 / 30 / 2025, page 60 / 125 3 / 6 5 to 7, characterized by the correction (CP) to be applied to the cooling module power being calculated according to equation 4: CP(t) = K'pe2(t) + K't J0 β2(τ)άτ + K'di-~- (4) where K'p is the proportional gain, K'i is the integral gain, K'd is the derivative gain and e2 is the difference between (Tc) and the measured temperature (T).

10. METHOD, according to any one of claims 1 to 9, characterized in the substep of adjusting a coil coating line configuration (1) comprising adjusting the cooling module power by correction (CP).

11. METHOD, according to any one of claims 5 to 9, characterized by: - ​​the ultraviolet curing device (4) comprising a UV module, - the setting step (100) further comprising setting a minimum temperature (Tmin) for the energy-cured ink, - the collection step (120) further comprising collecting the UV dose (D) from the UV module, - the sub-step of setting a coil coating line configuration (1) comprising: • assessing whether Tc is less than Tmin, • otherwise, adjusting the cooling module power by the CP correction, • if Tc is less than Tmin: * calculating the correction (CD) to be applied to the UV dose to which the wet film in at least a portion of the width must be exposed in the UV module, according to equation 5: CD = f2 (G, Gs) (5) Petition 870250099315, 10 / 30 / 2025, p.61 / 125 4 / 6 * adjust a coil coating line setting (1) different from the cooling module power, taking into account the calculated correction (CD).

12. METHOD, according to claim 11, characterized by the substep of adjusting a coil coating line configuration (1) different from the cooling module power comprising adjusting the UV module power so that the wet film in at least a portion of the moving strip width (S) is exposed to the corrected UV dose Dc = D + CD.

13. METHOD, according to claim 11, characterized by: - ​​the UV module being mobile along the path (P), - the setting step (100) further comprising adjusting a minimum UV dose (Dmin) to which the wet film is exposed in the UV module, - the collection step (120) further comprising collecting the length (L) between the UV module and the electron beam curing device (5), - the sub-step of adjusting a coil coating line configuration (1), different from the cooling device power (3), comprising: * evaluating whether D + CD is less than Dmin, * otherwise, adjusting the UV module power so that the wet film in at least a portion of the width of the mobile strip (S) is exposed with the corrected UV dose Dc = D + CD, * if D + CD is less than Dmin: • calculating the correction CL to be applied to the length between the UV module and the electron beam curing device (5) according to equation 6: Petition 870250099315, dated 10 / 30 / 2025, page.62 / 125 5 / 6 CL = f3 (G, Gs) (6) • adjust a coil coating line setting (1) in addition to the cooling module and UV module power, taking into account the calculated CL correction.

14. METHOD, according to claim 13, characterized by the substep of adjusting a coil coating line configuration (1), different from the power of the cooling module and the UV module, comprising adjusting the length between the UV module and the electron beam curing device (5) to the corrected length Lc = L + CL, so that the gloss value (Gs) is obtained in the organic coating in at least a portion of the width of the moving strip (S) downstream of the electron beam curing device (5).

15. COIL COATING LINE (1), characterized by sequentially comprising an ink applicator (2), a cooling device (3) comprising a cooling module, an ultraviolet curing device (4) and an electron beam curing device (5), the coil coating line (1) further comprising a gloss management tool for managing the gloss of an organic coating formed by applying and curing a wet film of an energy-cured ink on a moving strip (S) in the coil coating line (1), the gloss management tool comprising: - a configuration module that defines a defined gloss value (Gs) of the organic coating and a defined gloss range (Rs) of the organic coating gloss, - an acquisition module that collects the gloss measurement (G) of the organic coating in at least a downstream width portion of the electron beam curing device (5),- a correction module that corrects a deviation of the measured brightness (G) beyond the defined brightness range (Rs), the correction comprising a sub-step of Petition 870250099315, dated 10 / 30 / 2025, page 63 / 125 6 / 6 calculation of the correction (CP) to be applied to the cooling module power, taking into account (Gs) and the measured brightness (G), with a closed-loop controller and a sub-step of adjusting a coil coating line configuration (1) taking into account the calculated correction (CP). Petition 870250099315, dated 10 / 30 / 2025, page 64 / 125,

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