Method for managing the gloss of an organic coating and coating line on coils

Description

1 / 45 “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 870250098786, dated 10 / 29 / 2025, page 10 / 115 2 / 45 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 the pre-painting market (gloss typically between 15 and 30 GU for the construction market), paint suppliers add matting agents, as is the case 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 from 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 870250098786, dated 10 / 29 / 2025, page 11 / 115 3 / 45

[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] To that end, 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 energy-cured ink on 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 fixed brightness value Gs for the organic coating, a fixed brightness range Rs for the brightness of the organic coating, and a proportionality constant K based on a predefined linear mathematical relationship between the wet film temperature before ultraviolet curing and the brightness of the organic coating after electron beam curing. - collection of the wet film temperature (T) measurement in at least one portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device, and collection of the organic coating gloss (G) measurement in at least one portion of the width downstream of the electron beam curing device, - correction of a deviation in measured brightness G beyond the defined brightness range Rs, this correction step being composed of a sub-step of Petition 870250098786, dated 10 / 29 / 2025, page 12 / 115 4 / 45 Calculation of 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, according to equation 1: Tc = T + K (G - Gs) (1) and a sub-step of adjusting the coil coating line configuration, taking into account the calculated corrected temperature Tc.

[010] The method according to the invention may also have the optional features listed below, considered individually or in combination: The cooling device is chosen from among a forced-air cooler, a water spray cooler, a water-air mist spray cooler, and a roller cooler. The coil coating line also includes a heating device positioned between the ink applicator and the ultraviolet curing device. The method also includes an initial line adjustment step in which: If a plurality of process parameters and / or strip specifications are collected, at least one initial condition of the line 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 involves adjusting the cooling module power so that the wet film reaches the corrected temperature Tc. Petition 870250098786, dated 10 / 29 / 2025, page 13 / 115 5 / 45 minus a portion of the width of the movable strip downstream of the cooling module and upstream of the ultraviolet curing device, - The ultraviolet curing device comprises a UV module, The adjustment stage also includes setting a minimum temperature Tmin for the energy-cured ink. - The collection phase also includes collecting the UV D dose from the UV module, - The sub-step of adjusting a coil coating line configuration comprises: • Assess whether Tc is less than Tmin, • If not, adjust the cooling module power 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 and upstream of the ultraviolet curing device, • If Tc is less than Tmin: * Calculate the UV-corrected dose Dc to which the wet film, at least partly in width, must be exposed in the UV module, according to equation 2: Dc = f1 (D, G, Gs) (2) * adjust a coil coating line setting different from the cooling module power, taking into account the calculated corrected UV dose Dc, - 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, - the UV module is mobile along path P, Petition 870250098786, dated 10 / 29 / 2025, page 14 / 115 6 / 45 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 L-length between the UV module and the electron beam curing device. - a sub-step for adjusting a coil coating line configuration different from the cooling power. The module comprises: * Assess whether Dc is less than Dmin, * otherwise, 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, * if Dc is less than Dmin: • Calculate the corrected length Lc between the UV module and the electron beam curing device according to equation 3: Lc = f2 (L, G, Gs) (3) • adjust a coil coating line configuration different from the cooling module power and different from the UV module power, taking into account the calculated corrected length Lc, - The sub-step of adjusting a coil coating line configuration different from the cooling module power and different from the UV module power comprises adjusting the length between the UV module and the electron beam curing device to the corrected length Lc, so that the gloss value Gs is obtained in the organic coating in at least a portion of the width of the moving track downstream of the electron beam curing device. [ 011] A second object of the invention consists of a coil coating line comprising sequentially an ink applicator, a cooling device comprising a module of Petition 870250098786, dated 10 / 29 / 2025, page 15 / 115 7 / 45 cooling, 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 track in the coil coating line, the gloss management tool comprising: - an adjustment module that defines a defined brightness value Gs for the organic coating, a defined brightness range Rs for the brightness of the organic coating, and a proportionality constant K of a predefined linear mathematical relationship between the wet film temperature before ultraviolet curing and the brightness of the organic coating after electron beam curing, - an acquisition module that collects the wet film temperature (T) measurement in at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device, and collects the organic coating gloss (G) measurement 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 the calculation of 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, according to equation 1: Tc = T + K (G - Gs) (1) and adjust a coating line adjustment on coils, taking into account the calculated corrected temperature Tc.

[012] Other features and advantages of the invention will be described in greater detail in the following description. Petition 870250098786, dated 10 / 29 / 2025, page 16 / 115 8 / 45 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 coating line on coils, 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, after... as used in this application, refer to the positions and orientations of the different constituent elements of the coil sheathing 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 Petition 870250098786, dated 10 / 29 / 2025, p. 17 / 115 9 / 45 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, possible additional elements, the remainder consisting of zinc and unavoidable impurities due to processing.

[016] The method according to the invention also applies to dual-cure inks. The term dual-cure 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. Therefore, they are substantially solvent-free. Dual-cure 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 taken by the 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 film Petition 870250098786, dated 10 / 29 / 2025, page 18 / 115 10 / 45 wet ink on one or both sides of a strip with a defined ink thickness. In particular, its purpose is to apply the wet film of energy-cured ink. 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 coating to one or both sides of a strip with 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 specialist 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 is intended to contain, circulate and preferably heat the paint.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 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, slit applicator, metric rod applicator and slide applicator.

[023] The ink is usually applied with the ink applicator in Petition 870250098786, dated 10 / 29 / 2025, p. 19 / 115 11 / 45 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.

[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 UV-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 improves the temperature control of the wet paint film before Petition 870250098786, dated 10 / 29 / 2025, page 20 / 115 12 / 45 that its surface is cured in the UV curing device, alleviating temperature variations of the wet film entering the UV curing device, which would otherwise occur as a result of line variations. In fact, as 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...), the temperature of the wet film entering the UV 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 back of the 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, that is, 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] Cooling modules are preferably Petition 870250098786, dated 10 / 29 / 2025, page 21 / 115 13 / 45 chosen from a forced air cooler, a water spray cooler, a water-air spray cooler, and a roller cooler.

[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 outlet of the 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 adjust it 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 Petition 870250098786, dated 10 / 29 / 2025, page 22 / 115 14 / 45 for the gloss of the organic coating after complete curing of the wet film by electron beam.

[035] According to one variant, the UV 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 UV curing device (4) comprises a plurality of UV modules distributed along the width of the path P. In other words, the plurality of UV modules forms a row substantially parallel to the width of the path P, that is, 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 UV curing device.

[037] Thanks to this design, different portions of the path / strip width can be exposed to different doses of UV. 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 preferred. 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 UV curing device (4) is preferably mobile Petition 870250098786, dated 10 / 29 / 2025, page 23 / 115 15 / 45 along the P path of the moving strip. It allows the length between the UV 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, which is at its full thickness. It also freezes the surface roughness that appears on the surface of the wet film during UV curing and that develops during the time interval 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] 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 UV curing device (4). This wet film temperature measuring device measures the wet film temperature before it enters the UV 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 temperature measuring device of Petition 870250098786, dated 10 / 29 / 2025, page 24 / 115 16 / 45 wet film measures the temperature in only a portion of the width; the measurement in that portion can be considered relevant enough to control the brightness across 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 UV 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, the temperature of which is then measured by a wet film temperature measuring device.

[045] To further enhance control of the wet film temperature in the UV curing device, the wet film temperature measuring device (6) and the UV curing device (4) should not be separated by more than 2 meters, preferably not more than 1 meter, or the wet film temperature should not be measured for more than 4 seconds before curing the wet film in the UV 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 UV curing device may be thermally insulated to maintain the wet film at the measured temperature before being cured in the UV 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 Petition 870250098786, dated 10 / 29 / 2025, page 25 / 115 17 / 45 organic coating along the entire width of the P path of the moving strip or can measure gloss on only a portion of the width. Examples of gloss measuring devices are gloss meters. The measured gloss is preferably expressed in GU (Gloss Units). Gloss is preferably measured according to ISO 2813:2014 and EN 13523-2:2021 standards. Preferably, gloss is measured with a geometry of 20°, 60° or 85°, i.e., the angle of reflection is 20°, 60° or 85°. More preferably, 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 gloss measuring devices is positioned downstream of the EB curing device so that the entire width of the P path of the moving strip is covered. They form a row substantially parallel to the width of the P path. Consequently, the cooling device preferably comprises a plurality of cooling modules forming a row substantially parallel to the width of the P path, each cooling module being suitable for cooling a portion of the strip width, whose gloss is then measured by a gloss measuring device. Consequently, the UV curing device preferably comprises a plurality of UV modules forming a row substantially parallel to the width of the P path, each UV module being suitable for exposing a portion of the strip width to UV radiation, whose gloss is then measured by a gloss measuring device.

[049] The coil coating line (1) is preferably equipped with a strip speed measuring device, most preferably positioned at the level of a guide roller. An example of Petition 870250098786, dated 10 / 29 / 2025, p. 26 / 115 The 18 / 45 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 previous strip.

[052] Alternatively, the coiled 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 at 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 are moved apart. The total length of metal stored depends on the line's design speed, generally 60 seconds of steady-state metal processing time. When the input section Petition 870250098786, dated 10 / 29 / 2025, p. 27 / 115 19 / 45 of the coil coating line stops, the roller banks move towards each other, and the metal stored in the accumulator continues to feed the rest of the coil coating line.

[054] The coil coating line (1) may also 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 undergoes 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. Preferably, degreasing is carried out in an alkaline environment. The conversion treatment includes the application to the strip of a conversion solution that reacts chemically with the surface, enabling the formation of a conversion layer.This last step 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 to the strip to form a primer coating. The primer section may comprise 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, a UV curing device and / or a Petition 870250098786, dated 10 / 29 / 2025, p. 28 / 115 20 / 45 EB healing 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 cutting device to separate the strip from the next one to be processed on the line. The coil coating line (1) may further comprise a heating device, positioned along the P path of the moving strip, adjacent to the cooling device.

[058] The heating device can be positioned upstream or downstream of the cooling device. Its function is to replace the cooling device when the wet paint film is not sufficiently heated before its surface is cured in the UV 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 sprinkler heater, a water-air mist sprinkler 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 Petition 870250098786, dated 10 / 29 / 2025, p. 29 / 115 21 / 45 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] The heating modules are preferably chosen from among an infrared heater, an induction heater, a convector, a forced air heater, a water spray heater, a water and air spray heater and a portion of the width of a heated roll. 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 strip a base heater covering 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 temperature of the wet film at the outlet of the heating device is supplied by the base heater. Each module Petition 870250098786, dated 10 / 29 / 2025, page 30 / 115 The 22 / 45 heating module, among its various heating modules, independently supplies the remaining portion of the energy and can be adjusted as needed.

[065] The heating device is preferably positioned above path P, so that the wet film applied to the top 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 cooling module, an ultraviolet curing device (4) and an electron beam curing device (5).

[067] The gloss management tool comprises an adjustment module to define a gloss value Gs for the organic coating, a gloss range Rs for the gloss of the organic coating and a proportionality constant K of a predefined linear mathematical relationship between the wet film temperature before ultraviolet curing and the gloss of the organic coating after electron beam curing.

[068] The gloss management tool further comprises an acquisition module configured to collect the wet film temperature T measurement in at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device and to collect the organic coating gloss G measurement in at least a portion of the width downstream of the electron beam curing device. Petition 870250098786, dated 10 / 29 / 2025, page 31 / 115 23 / 45

[069] The gloss management tool further comprises a correction module configured to correct a deviation of the measured gloss G beyond the defined gloss range Rs, the correction comprising the calculation of 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, according to equation 1: Tc = T + K (G - Gs) (1) and the adjustment of the coil coating line configuration, taking into account the calculated corrected temperature Tc.

[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 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 radical-curing 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 linear 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 corrected efficiently and reproducibly. Petition 870250098786, dated 10 / 29 / 2025, page 32 / 115 24 / 45 adjusting 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.

[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 regulation.

[076] The defined gloss value Gs of the organic coating is defined first. 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. Petition 870250098786, dated 10 / 29 / 2025, p. 33 / 115 25 / 45

[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 from the coil coating line management tool or the coil coating line order book, in particular from the scheduling tool. The defined gloss range (Rs) of the gloss can also be obtained from standards such as EN10169:2013.

[078] Furthermore, since gloss management depends on the linear mathematical relationship between the wet film temperature before ultraviolet curing and the gloss of the organic coating after electron beam curing, the proportionality constant K of this linear mathematical relationship must be defined for the regulation to be correct.

[079] The proportionality constant K can be obtained in a calibration step performed before the setup step. During this calibration step, wet films of the reverse-curing ink to be used in the roll 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 Petition 870250098786, dated 10 / 29 / 2025, page 34 / 115 26 / 45 can be performed all at once and does not need to be performed every time the method according to the invention is implemented.

[080] From a practical point of view, 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. In particular, K is the proportionality constant of the linear mathematical relationship T = T0 - K G. 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 in the gloss management tool, in particular in the configuration module.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.

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

[082] In a second step (120) of the method for gloss management, the temperature T of the wet film is measured in at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device, and the gloss G of the organic coating is measured in at least a portion of the width downstream of the electron beam curing device.

[083] Preferably, the temperature is measured with a device Petition 870250098786, dated 10 / 29 / 2025, page 35 / 115 27 / 45 wet film temperature measurement, as described above, and gloss is measured with a gloss measuring device, as described above.

[084] Preferably, both measurements are taken 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 s, less than 2 seconds. More preferably, both measurements are substantially continuous or continuous. Preferably, both measurements are collected at time intervals short enough 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, both measurements are collected substantially continuously or continuously. Preferably, the measurements are collected in the brightness management tool, in particular in the acquisition module, more preferably automatically with the appropriate interface.

[085] 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 a single width portion, on several width portions, or across the entire width of the moving strip. If not implemented across the entire width, it is 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 various width portions, so that the temperature in each width portion can be adjusted Petition 870250098786, dated 10 / 29 / 2025, p. 36 / 115 28 / 45 regardless of the other portions.

[086] Similarly, it is possible to measure and collect: - the gloss G of the organic coating in a single width portion, if the measurement in that width portion is considered relevant enough to manage the gloss of the entire width of the strip, or - the sheens of the organic coating in a plurality of width portions, so that the sheen in each width portion can be managed independently of the other portions.

[087] In one variant, the collection stage is carried out after the prey stage.

[088] In another variant, particularly during continuous coil coating line operation, the take-up step can be performed in parallel with the setting step. In this continuous operation case, as the strip is composed of different coils connected 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, the defined gloss range Rs and / or the constant K, 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 setting step is performed.

[089] 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 corrected temperature Tc is to be Petition 870250098786, dated 10 / 29 / 2025, page 37 / 115 The 29 / 45 area reached by 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 is calculated according to equation 1: Tc = T + K (G - Gs) (1)

[090] 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 s, less than 2 seconds. More preferably, the assessment is substantially continuous or continuous.

[091] Once the corrected temperature has been calculated, the result of the calculation, i.e., the corrected temperature Tc, is preferably made available to a line operator. The latter can then make the necessary corrections.

[092] In general, a line adjustment is adjusted taking into account the calculated corrected temperature Tc, 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. In particular, a line adjustment 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 and upstream of the ultraviolet curing device.

[093] In a first variant illustrated in Figure 2, once the corrected temperature is calculated, the power of the cooling 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 and upstream of the ultraviolet curing device. Adjusting the power of the cooling module involves switching the cooling module on or off. Thanks to the adjustment of the cooling module, the temperature of the wet film in the width portion downstream of the cooling module and upstream of the curing device Petition 870250098786, dated 10 / 29 / 2025, page 38 / 115 30 / 45 by ultraviolet is corrected, obtaining a gloss value of Gs in the organic coating 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.

[094] 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 corrected temperature has been calculated, the heating module is switched on and its power 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 way of correcting gloss is particularly useful in cases where the cooling module is already at its minimum capacity or switched off and the wet film temperature upstream of the ultraviolet curing device needs to be increased further.

[095] Alternatively, in the case where the coil coating line is equipped with an inductor upstream of the paint applicator, once the corrected temperature is calculated, the inductor power is adjusted so that the strip temperature at the paint applicator level 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 and upstream of the ultraviolet curing device. This alternative way of correcting gloss is particularly useful in cases where the cooling module is already at its minimum capacity or switched off and the wet film temperature upstream of the ultraviolet curing device needs to be increased further.

[096] In one variant, the correction step (130) is performed after Petition 870250098786, dated 10 / 29 / 2025, page 39 / 115 31 / 45 the collection stage (120).

[097] 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 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.

[098] Optionally, the method also comprises a step (110) during which the initial line conditions are defined. This step is called the initial line setup 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 roll 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 conditions suitable for achieving the defined gloss value, Gs. In this case, the cooling module may not cool adequately and / or may take some time to reach the power corresponding to the corrected temperature, Tc, and / or may not be powerful enough to allow the wet film to reach the corrected temperature, Tc.Consequently, a portion of the coated strip may have to be discarded because the gloss is out of specification. Additionally, the UV dose to which the wet film must be exposed to initiate the surface roughness that will result in the defined gloss value may not be adequate. In this case, the cooling module needs to compensate for the shifted UV dose, possibly through intense cooling, which takes time. Again, a portion of the coated strip may have to be discarded. Petition 870250098786, dated 10 / 29 / 2025, p. 40 / 115 32 / 45 because the gloss is out of specification. To minimize the length of the coated strip being out of specification, it is advantageous to set the initial conditions of the line.

[099] To this end, in a first sub-step, a plurality of process parameters and / or specifications of the coated strip are collected. An example of process parameters is the initial line speed LS0. Preferably, it 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 programming tool, and / or deduced from the order book. For example, the initial film thickness FTh0 can be deduced from the organic coating thickness specified in the order book.

[0100] Once the process parameters and / or specifications have been collected, in a second sub-step, the initial conditions of the line are defined taking into account the collected process parameters and / or specifications. In particular, they are calculated from the parameters Petition 870250098786, dated 10 / 29 / 2025, page 41 / 115 33 / 45 and / or collected process 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.

[0101] 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 adjustment step. The initial length L0 can be defined based on data obtained in a calibration step performed before the initial line adjustment step.

[0102] 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.

[0103] In one variant, the initial line definition step (110) is performed before the definition step (100). This helps to start production with line conditions already optimized for the first reel of the production campaign, as well as an initial combination of the defined brightness value Gs, the defined brightness range Rs, and the constant K. During production, the collection step and the correction step can be performed to manage brightness. When any of the defined parameters, in particular any of the defined brightness values ​​Gs, the defined brightness range Rs, and / or the constant K, needs to be modified for some reason, such as a change in brightness. Petition 870250098786, dated 10 / 29 / 2025, page 42 / 115 34 / 45 specified or a change in the energy-cured ink, depends on the performance of the collection step (120) and the correction step (130) to maintain the measured gloss within the defined gloss range Rs.

[0104] 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 the defined brightness value Gs, the defined brightness range Rs and / or the constant K, needs to be modified for any reason, the initial line settings can be reset to help minimize the transition period.

[0105] 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.

[0106] 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. Resetting the line conditions when one of these changes occurs helps to achieve the defined gloss value as quickly as possible.

[0107] A second embodiment of the method is now described with reference to Figure 3.

[0108] This implementation differs primarily from the first, as the correction stage includes additional sub-stages for: Petition 870250098786, dated 10 / 29 / 2025, page 43 / 115 35 / 45 - ensure that the calculated corrected temperature Tc is not below a minimum temperature Tmin that would block diffusion and / or mobility phenomena, and - Correct the deviation of the measured brightness G accordingly.

[0109] Thanks to this configuration, it is more guaranteed that the wet film will react properly to UV exposure.

[0110] The details provided in describing the first embodiment apply to the second embodiment. The additional steps and corresponding features are described in detail now.

[0111] The definition step (100) also includes setting a minimum temperature Tmin for the energy-cured ink. This temperature may be that recommended by the ink supplier. Alternatively, it may be identified during a calibration step performed before the adjustment 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 gloss management tool with the ink reference from the roll coating line order book, specifically in the scheduling tool.

[0112] 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 coil coating line management tool, but, for a given power, the UV dose Petition 870250098786, dated 10 / 29 / 2025, page 44 / 115 The actual UV dose to which the wet film is exposed varies with the speed of the LS line. Consequently, the UV dose is calculated based on the UV module power and line speed and collected. The line speed itself is usually known to the operator, possibly by the roll coating line management tool.

[0113] 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.

[0114] During the correction step (130), once the corrected temperature Tc has been calculated, it is compared with the minimum temperature Tmin. If Tc is greater than Tmin, the power of the cooling 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 and upstream of the ultraviolet curing device, as in the first embodiment. Alternatively, in the case where the coil coating line is equipped with a heating device comprising a heating module and adjacent to the cooling device, once the corrected temperature has been calculated, 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.Adjusting the heating module's power involves switching it on. Alternatively, if the coil coating line is equipped with an inductor upstream of the paint applicator, once the corrected temperature is calculated, the inductor's power is adjusted so that the strip temperature is at the correct level. Petition 870250098786, dated 10 / 29 / 2025, p. 45 / 115 37 / 45 The ink applicator should be 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 and upstream of the ultraviolet curing device.

[0115] If Tc 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 corrected UV dose Dc 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 2: Dc = f1 (D, G, Gs) (2)

[0116] Equation (2) can be obtained in a calibration step performed before the correction step, preferably before the adjustment 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 f1 can therefore be deduced for each energy-cured ink. This calibration step can be performed once and for all and does not need to be performed every time the method according to the invention is implemented.

[0117] Preferably, the function f1 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 is defined during the configuration step. By predefined, it is understood that a calibration step, preferably as described above, was performed before the implementation of the method on the coil coating line. The function f1 can be manually entered in the tool. Petition 870250098786, dated 10 / 29 / 2025, page 46 / 115 38 / 45 gloss management, particularly 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, particularly in the programming tool.

[0118] For example, it has been observed that, for commercially available energy-cured paints for coating steel coils, f1 is generally related to a decreasing gloss curve towards an asymptote as the UV dose increases.

[0119] Once the corrected UV dose has been calculated, the result of the calculation, i.e., the corrected UV dose Dc, is preferably made available to a line operator. The latter can then make the necessary corrections.

[0120] In general terms, a line adjustment 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 corrected UV dose Dc, so that the brightness value Gs is obtained on the organic coating in the portion of at least one width of the moving strip downstream of the electron beam curing device.

[0121] In the variant illustrated in Figure 3, once the corrected UV dose has been calculated, the UV module power is adjusted, in particular reduced, so that the wet film in at least one width portion 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 width portion of the UV module is corrected and the brightness value Gs is obtained in the organic coating in the width portion 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 help of the brightness management tool.

[0122] A third way of implementing the method is now Petition 870250098786, dated 10 / 29 / 2025, page 47 / 115 39 / 45 described with reference to Figure 4.

[0123] This implementation differs primarily from the second, as the correction stage includes additional sub-stages for: - ensure that the calculated corrected UV dose Dc is not less than a minimum UV dose Dmin to which the wet film can be exposed, - Correct the deviation of the measured brightness G accordingly.

[0124] Thanks to this configuration, the method further prevents under-curing of the wet film in the UV curing device, which can impair gloss.

[0125] The details provided in the description of the first and second embodiments apply to the third embodiment. The additional steps and corresponding resources are described in detail below.

[0126] 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.

[0127] The definition step (100) also includes setting 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 from the programming tool. Petition 870250098786, dated 10 / 29 / 2025, page 48 / 115 40 / 45

[0128] 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.

[0129] During the correction step (130), once the corrected UV dose Dc has been calculated, it 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.

[0130] 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 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 corrected length Lc between the UV module and the electron beam curing device, according to equation 3: Lc = f2 (L, G, Gs) (3)

[0131] Equation (3) can be obtained in a calibration step performed before the correction step, preferably before the step of Petition 870250098786, dated 10 / 29 / 2025, page 49 / 115 41 / 45 press. 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 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.

[0132] Preferably, the function f2 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 configuration 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 f2 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.

[0133] For example, it has been observed that, for commercially available radical cure paints for coating steel coils, f2 is generally related to a gloss curve that decreases towards an asymptote as L increases.

[0134] Once the corrected length has been calculated, the result of the calculation, i.e., the corrected length Lc, is preferably made available to a line operator. The latter can then make the necessary corrections.

[0135] In general terms, a line configuration different from the cooling module power, different from the cooling module power Petition 870250098786, dated 10 / 29 / 2025, p. 50 / 115 42 / 45 heating, if applicable, different from the inductor power, if applicable, and different from the UV module power is adjusted taking into account the calculated corrected length Lc, so that the brightness 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.

[0136] In the variant illustrated in Figure 4, once the corrected length has been calculated, the length between the UV module and the electron beam curing device is adjusted, in particular shortened, to the corrected length Lc, 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.

[0137] 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, to 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.

[0138] The invention also relates to a method for forming an organic coating on 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: Petition 870250098786, dated 10 / 29 / 2025, page 51 / 115 43 / 45 - Apply a wet film of energy-cured ink to the moving strip using the ink 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 controlled by: - Define a fixed brightness value Gs for the organic coating, a fixed brightness range Rs for the brightness of the organic coating, and a proportionality constant K based on a predefined linear mathematical relationship between the wet film temperature before ultraviolet curing and the brightness of the organic coating after electron beam curing. - collect the wet film temperature (T) measurement along at least one portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device, and collect the organic coating brightness (G) measurement along at least one portion of the width downstream of the electron beam curing device. - correct a deviation in the measured brightness G beyond the fixed brightness range Rs, this correction step comprising 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 ultraviolet curing device, according to equation 1: Tc = T + K (G - Gs) (1) and a Substep of adjusting the coil coating line, considering the calculated corrected temperature Tc.

[0139] All details provided regarding the method of Petition 870250098786, dated 10 / 29 / 2025, page 52 / 115 44 / 45 gloss management and all details provided regarding the coil coating line apply to the organic coating formation method.

[0140] 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 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 metal strip using the ink 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, a gloss range Rs for the gloss of the organic coating, and a proportionality constant K from a predefined linear mathematical relationship between the wet film temperature before ultraviolet radiation, the curing temperature, and the gloss of the organic coating after electron beam curing. - Collection of the wet film temperature (T) measurement along at least a portion of the width of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device, and collection of the organic coating gloss (G) measurement along at least a portion of the width downstream of the Petition 870250098786, dated 10 / 29 / 2025, page 53 / 115 45 / 45 electron beam curing device, - corrects a deviation in the measured brightness G beyond the defined brightness range Rs, this correction step consisting of a sub-step 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, according to equation 1: Tc = T + K (G - Gs) (1) and a sub-step of adjusting the coil coating line configuration, taking into account the calculated corrected temperature Tc.

[0141] Optionally, the metal strip can be heated before applying the wet film of energy-cured paint.

[0142] All details provided regarding the gloss management method and all details provided regarding the coil coating line apply to the prepainted metal manufacturing method. Petition 870250098786, dated 10 / 29 / 2025, page 54 / 115

Claims

1 / 5 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 gloss value (Gs) for the organic coating, a gloss range (Rs) for the gloss of the organic coating and a proportionality constant (K) of a predefined linear mathematical relationship between the temperature of the wet film before ultraviolet curing and the gloss of the organic coating after electron beam curing,- collect (120) the wet film temperature (T) measurement 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 collect the organic coating gloss (G) measurement in at least one portion of the width downstream of the electron beam curing device (5), - correct (130) a deviation of the measured gloss (G) beyond the defined gloss range (Rs), this correction step comprising 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), according to equation 1: Tc = T + K (G - Gs) (1) and a sub-step of adjusting a coil coating line configuration (1), taking into account the calculated corrected temperature (Tc). Petition 870250098786, dated 10 / 29 / 2025, page 55 / 115 2 / 5, 2. METHOD, according to claim 1, characterized in that the cooling device (3) is chosen from among a forced air cooler, a water spray cooler, a water and air spray cooler and a cooled roller.

3. METHOD, according to any one of claims 1 to 2, characterized in that the coil coating line (1) further comprises a heating device positioned between the ink applicator (2) and the ultraviolet curing device (4).

4. METHOD, according to any one of claims 1 to 3, characterized in the substep of adjusting the coil coating line (1) comprising adjusting the power of the cooling module so that the wet film reaches the corrected temperature (Tc) in at least a portion of the width of the moving strip (S) downstream of the cooling module and upstream of the ultraviolet curing device (4).

5. METHOD, according to any one of claims 1 to 3, 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 power of the cooling module so that the wet film reaches the corrected temperature (Tc) in at least a portion of the width of the moving strip (S) downstream of the cooling module and Petition 870250098786, 10 / 29 / 2025, p.56 / 115 3 / 5 upstream of the ultraviolet curing device (4), • if Tc is less than Tmin: * calculate the corrected UV dose (Dc) to which the wet film in at least a portion of the width must be exposed in the UV module according to equation 2: Dc = f1 (D, G, Gs) (2) * adjust a different coil coating line setting (1) of cooling module power, taking into account the calculated corrected UV dose (Dc).

6. METHOD, according to claim 5, characterized by the substep of adjusting a coating line configuration on coils (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).

7. METHOD, according to claim 5, characterized by: - ​​the UV module being mobile along the path (P), - the setting step (100) further comprising the adjustment of a minimum UV dose (Dmin) to which the wet film is exposed in the UV module, - the collection step (120) further comprising the collection of 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 module power comprising: * evaluating whether Dc is less than Dmin, * otherwise, adjusting the UV module power so that the Petition 870250098786, of 10 / 29 / 2025, p.57 / 115 4 / 5 wet film in at least a portion of the width of the moving strip (S) is exposed with the corrected UV dose (Dc), * if Dc is less than Dmin: • calculate the corrected length (Lc) between the UV module and the electron beam curing device (5) according to equation 3: Lc = f2 (L, G, Gs) (3) • adjust a coil coating line setting (1) different from the cooling module power and different from the UV module power, taking into account the calculated corrected length (Lc).

8. METHOD, according to claim 7, characterized by the substep of adjusting a coil coating line configuration (1), different from the cooling module power and different from the UV module power, comprising adjusting the length between the UV module and the electron beam curing device (5) to the corrected length (Lc), so that the gloss value (Gs) is obtained on the organic coating in at least a portion of the width of the moving strip (S) downstream of the electron beam curing device (5).

9. 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 track in the coil coating line (1), the gloss management tool comprising: - an adjustment module that defines a defined gloss value (Gs) of the organic coating, a defined gloss range (Rs) of the gloss of the Petition 870250098786, dated 29 / 10 / 2025,pg. 58 / 115 5 / 5 organic coating and a proportionality constant (K) of a predefined linear mathematical relationship between the temperature of the wet film before ultraviolet curing and the gloss of the organic coating after electron beam curing, - an acquisition module that collects the temperature (T) measurement of the wet film in at least a portion of the width of the moving track downstream of the cooling module and upstream of the ultraviolet curing device (4) and collects the gloss (G) measurement of the organic coating in at least a portion of the width downstream of the electron beam curing device (5), - a correction module that corrects a deviation of the measured gloss (G) beyond the defined gloss range (Rs), the correction comprising the calculation of 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 (4),according to equation 1: Tc = T + K (G - Gs) (1) and adjust a coating line configuration on coils (1), taking into account the calculated corrected temperature (Tc)., 10. COIL COATING LINE (1), according to claim 9, characterized in that the cooling device (3) is chosen from a forced air cooler, a water spray cooler, a water and air spray cooler and a cooled roll. Petition 870250098786, dated 10 / 29 / 2025, p. 59 / 115

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