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

Description

1 / 43 “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 managing 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 870250098780, dated 10 / 29 / 2025, page 10 / 111 2 / 43 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 870250098780, dated 10 / 29 / 2025, page 11 / 111 3 / 43

[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 an 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 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 heating device comprising a heating 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 fixed gloss range (Rs) for the gloss of the organic coating, - collect the temperature (T) measurement of the wet film on at least one width portion of the moving strip upstream of the ultraviolet curing device and collect the gloss (G) measurement of the organic coating on at least one width portion downstream of the electron beam curing device, - Correcting a deviation from the measured brightness (G) beyond the defined brightness range (Rs), this correction step comprising a sub-step of calculating the correction (CT) to be applied to the wet film temperature, in at least a portion of the width upstream of the ultraviolet curing device, taking into account (Gs) and the measured brightness (G), with a loop controller. Petition 870250098780, dated 10 / 29 / 2025, page 12 / 111 4 / 43 closed, and a sub-step of adjusting a coil coating line configuration, taking into account the calculated correction (CT).

[010] The method according to the invention may also have the optional features listed below, considered individually or in combination: The closed-loop controller is a proportional-integral-derivative controller. - the correction (CT) is a function of the difference between (Gs) and the measured brightness (G), - The correction (CT) to be applied to the wet film temperature is calculated according to equation 1: CT(t) = Kpe1 (t) + KtJ0e1 (x)dx + 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), the method also includes an initial line setup step where: If a plurality of process parameters and / or strip specifications are collected, at least one initial line condition between the initial power (PW0) of the heating 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 the strip specifications that were collected. The coil coating line also includes an inductor upstream of the paint applicator. - The sub-step of adjusting a coiled coating line configuration comprises adjusting the inductor power so that the Petition 870250098780, dated 10 / 29 / 2025, page 13 / 111 5 / 43 wet film reaches the corrected temperature Tc = T + CT in at least a portion of the width of the moving strip downstream of the heating module and upstream of the ultraviolet curing device, - The sub-step of adjusting a coil coating line configuration comprises adjusting the power of the heating module so that the wet film reaches the corrected temperature Tc = T + CT in at least a portion of the width of the moving strip downstream of the heating module and upstream of the ultraviolet curing device. - the sub-step of adjusting a coiled coating line configuration comprises adjusting the heating module power by a correction (CP) calculated according to equation 2: CP(t) = K'pCT(t) + K\ £CT(r)dT + K'D^-— (2) where K'p is the proportional gain, K'i is the integral gain, K'd is the derivative gain and CT is the correction to be applied to the wet film temperature, The ultraviolet curing device comprises a UV module. The adjustment stage also includes setting a maximum temperature, Tmax, for the ultraviolet curing 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 T + CT exceeds Tmax, • If not, adjust the power of the heating module, • If T + CT exceeds Tmax: - Calculate the correction (CD) to be applied to the UV dose to which the wet film, at least in a portion of its width, must be exposed in the UV module, according to equation 3: Petition 870250098780, dated 10 / 29 / 2025, page 14 / 111 6 / 43 CD = fl (G, Gs) (3) - Adjust a coil coating line setting different from the heating module power, taking into account the calculated correction (CD), - The sub-step of adjusting a coil coating line configuration, other than the heating 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 the path (P), The adjustment step also includes setting a maximum UV dose, Dmax, 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 heating module power, comprises: - Assess whether D + CD is greater than Dmax, 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 to the corrected UV dose Dc = D + CD. - If D + CD is greater than Dmax: • Calculate the correction (CL) to be applied to the length between the UV module and the electron beam curing device, according to equation 4: CL = f2 (G, Gs) (4) • adjustment of a coil coating line configuration different from the heating module power and different from the power of Petition 870250098780, dated 10 / 29 / 2025, page 15 / 111 7 / 43 UV module, taking into account the calculated correction (CL); - The sub-step of adjusting a coil coating line configuration different from the heating 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 = L + CL, so that the gloss value (Gs) is obtained in the organic coating in the portion of at least one width of the moving strip downstream of the electron beam curing device. - The heating module is chosen from among an infrared heater, an induction heater, a convector heater, a forced-air heater, a water spray heater, a water-air mist spray heater, and a heated roller.

[011] A second object of the invention consists of a coil coating line comprising sequentially an ink applicator, a heating device comprising a heating 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 gloss value (Gs) for the organic coating and a gloss range (Rs) for the organic coating, - an acquisition module that collects the temperature (T) measurement of the wet film in at least a portion of the width of the moving strip upstream of the ultraviolet curing device 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, Petition 870250098780, dated 10 / 29 / 2025, page 16 / 111 8 / 43 - a correction module that corrects a deviation of the measured brightness (G) beyond the defined brightness range (Rs), comprising the correction as a sub-step of calculating the correction (CT) to be applied to the wet film temperature, in at least a portion of the upstream width of the ultraviolet curing device, taking into account (Gs) and the measured brightness (G), with a closed-loop controller and a sub-step of adjusting the coil coating line configuration, taking into account the calculated correction (CT).

[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, which is provided for explanatory purposes only and is in no way intended to be 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 coating line on coils.

[015] The method according to the invention is intended for strips, such as metal strips. Steel, whether carbon steel or stainless steel, aluminum, copper Petition 870250098780, dated 10 / 29 / 2025, p. 17 / 111 9 / 43 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 containing 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 composed of 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 composed of aluminum, magnesium, silicon, and possibly 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-curing 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. They are therefore substantially solvent-free. Dual-cure 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, in the form Petition 870250098780, dated 10 / 29 / 2025, page 18 / 111 10 / 43 sequential along the path (P) of the moving strip, an ink applicator (2), a heating device (3) comprising a heating module, an ultraviolet curing device (4) and an electron beam curing device (5).

[018] The path (P) is the path followed by the strip (S) from its entry into the coil coating line to its exit. It has width and 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 film of ink to 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. It is an automated machine that coats 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 various paint roller coating designs, depending on the configuration of the coil coating line, the types of paints used and the types of strips to be coated. A person skilled in the art will know which design best suits each case. Generally, the paint coating roller comprises a paint container, a steel or ceramic collection roller and a rubber-coated coating roller. The purpose of the paint container is 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 applicator of Petition 870250098780, dated 10 / 29 / 2025, p. 19 / 111 11 / 43 paint (2) is a curtain coating system. In this case, a curtain of paint is applied to the horizontal strip normally transverse to the curtain. The paint falls from a height under gravity from a curtain or cascade die 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 coater, dip or meniscus coater, groove coater, measuring rod coater, slide coater.

[023] The ink is generally 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. It also further facilitates gloss management as it minimizes energy requirements at the heating module level and thus minimizes heating module inertia. In the case of a paint coating roller, the paint heating device may be a container heater, i.e., a heater positioned inside or around the paint container. It may also be a temperature-controlled roller, in particular a temperature-controlled pickup roller, possibly in combination with the container heater. In the case of a curtain coater, the paint heating device may be a heater positioned upstream of the curtain matrix.It could 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 temperature of the paint and / or Petition 870250098780, dated 10 / 29 / 2025, p. 20 / 111 12 / 43 the temperature of the wet film at the level of the paint applicator. The temperature device can be, for example, a temperature sensor, a pyrometer, or a thermal camera.

[026] The coil coating line (1) further comprises a heating device (3) comprising a heating module, positioned along the path (P) of the moving strip, downstream of the ink applicator (2) and upstream of the ultraviolet (UV) curing device (4). Its purpose is to heat the wet film of the energy-cured ink. The heating device further improves the temperature control of the wet film of the ink before its surface is cured in the UV curing device. As the temperature of the strip exiting the ink applicator decreases at a rate that depends on several parameters (nature of the strip, width of the strip, thickness of the strip, line speed...), the temperature of the wet film entering the UV curing device can vary significantly from time to time, which would negatively affect the gloss. Thanks to the heating device, the temperature of the wet film can be adjusted.

[027] 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 and air 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.

[028] According to one variant, the heating device is made of a heating module that covers the entire width of the path (P) of the moving strip. In this case, the wet film is heated uniformly along its width as it passes (through) the heating device. Petition 870250098780, dated 10 / 29 / 2025, p. 21 / 111 13 / 43

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

[030] 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-air spray heater and a portion of the width of a heated roller. Preferably, the heating modules are infrared heaters.

[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 heating device outlet is less than 1 °C. Improves the homogeneity of the coating gloss across the strip width.

[032] According to another variant, the heating device (3) 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. The base heater can be an infrared heater or an inductor. Thanks to this design, a portion of the energy required to achieve the correct wet film temperature at the output of the heating device is supplied by the base heater. Each heating module of the plurality of heating modules independently supplies the remaining portion of the energy and can adjust it accordingly. Petition 870250098780, dated 10 / 29 / 2025, page 22 / 111 14 / 43 requested.

[033] The heating device (3) is preferably positioned above the path (P) so that the wet film applied to the upper side of the strip is directly heated. The heating device can also be positioned above and below the 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, once the wet film has been fully cured by electron beam.

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

[036] According to another variant, the UV curing device (4) comprises a plurality of UV modules distributed across 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 to each other, but may be physically inseparable from each other. They may be individually controllable portions 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. It helps to correct and minimize brightness variations across the strip width. Consequently, the Petition 870250098780, dated 10 / 29 / 2025, page 23 / 111 15 / 43 The heating device preferably comprises a plurality of heating modules forming a row substantially parallel to the width of the path (P), each heating module being suitable for heating a portion of the width of the strip, 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 heating 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 movable along the path (P) of the moving strip. It allows adjusting the length between the UV curing device and the EB curing device, which can be extended or shortened. In fact, it has been observed that wrinkles or surface roughness initiated during UV curing are developed during the time interval between UV curing and EB curing, which impacts the gloss of the organic coating.

[040] In the case of a plurality of UV modules, each UV module is preferentially mobile along the 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 in its entire thickness. It further 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. Petition 870250098780, dated 10 / 29 / 2025, p. 24 / 111 16 / 43

[042] The coil coating line (1) further comprises a wet film temperature measuring device (6) positioned downstream of the heating device (3) and upstream of the UV curing device (4). This wet film temperature measuring device measures the temperature of the wet film before it enters the UV curing device. It can measure the wet film temperature along the entire width (P) of the moving strip or it can measure the temperature only in a portion of the width. Examples of wet film temperature measuring devices are pyrometer, thermal camera and thermocouple. 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 only in a portion of the width, the measurement in this portion can be considered sufficiently relevant to manage the brightness of the entire width of the strip.

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

[045] In order to further increase the temperature control of the wet film in the UV curing device, the wet film temperature measuring device (6) and the UV curing device (4) are not separated by more than 2 meters, preferably not by more than 1 meter, or the Petition 870250098780, dated 10 / 29 / 2025, page 25 / 111 17 / 43 The wet film temperature is not measured more than 4 seconds before the wet film is cured in the UV curing device, preferably no more than 2 seconds. Alternatively or additionally, the portion of the path (P) of the moving strip between the wet film temperature measuring device and the UV curing device can 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 the organic coating along the entire path width (P) of the moving strip or it can measure the gloss only in a portion 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 135232:2021 standards. Preferably, the gloss is measured with a 20° geometry, a 60° geometry or an 85° geometry, i.e., the reflection angle is 20°, 60° or 85°. More preferably, the gloss is measured with a 60° geometry.

[047] In the case where the brightness measuring device measures brightness only in a portion of the width, the measurement in this portion may 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 path width (P) of the moving strip is covered. They form a row substantially parallel to the path width (P). Consequently, Petition 870250098780, dated 10 / 29 / 2025, p. 26 / 111 18 / 43 The heating device preferably comprises a plurality of heating modules forming a row substantially parallel to the path width (P), each heating module being suitable for heating a portion of the strip width, the brightness of which is then measured by a brightness measuring device. Consequently, the UV curing device preferably comprises a plurality of UV modules forming a row substantially parallel to the path width (P), each UV module being suitable for exposing a portion of the strip width to UV radiation, the brightness of which is then measured by a brightness 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 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 hot strip at the paint applicator favors paint application. Furthermore, the temperature reached by the strip at 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 coil coating line can be coupled to a galvanizing line so that the coated strip Petition 870250098780, dated 10 / 29 / 2025, p. 27 / 111 19 / 43 with the metal alloys contained in the galvanizing line bath being coated directly with the organic coating without having to first roll it up and then unroll it.

[053] The coil coating line (1) may further comprise an input accumulator (10) located in the line's input section, downstream of the unwinder, if applicable. The accumulator is equipment that “accumulates” a certain quantity of strip. It 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 separated. The total stored length of metal depends on the line's designed 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 undergoes a surface preparation step. This type of preparation comprises at least one step selected from rinsing, degreasing and conversion treatment. The aim of rinsing is to remove loose dirt particles, possible residues of conversion solutions, soaps that may have formed and to achieve a clean and reactive surface. The aim of degreasing is to clean the surface by removing all traces of organic dirt, metal particles and dust from the surface. Preferably, degreasing is carried out in an alkaline environment. The conversion treatment involves applying a conversion solution to the strip which reacts chemically with the surface and thus allows the formation of Petition 870250098780, dated 10 / 29 / 2025, p. 28 / 111 20 / 43 a conversion layer. This last one increases the paint's 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 layer. The primer section may comprise a primer paint applicator and a curing apparatus. Depending on the nature of the primer, the curing apparatus 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 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 winder (13) for rewinding the strip that has been coated on the line. The rewinder may be combined with a cutout to separate the strip from the next one processed on the line.

[058] 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 an 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 heating device (3) comprising a module of Petition 870250098780, dated 10 / 29 / 2025, page 29 / 111 21 / 43 heating, an ultraviolet curing device (4) and an electron beam curing device (5).

[059] The gloss management tool comprises a configuration module for defining a defined gloss value (Gs) for the organic coating and a gloss range (Rs) for the organic coating.

[060] The gloss management tool further comprises an acquisition module configured to collect the wet film temperature (T) measurement in at least one width portion of the moving strip downstream of the heating module and upstream of the ultraviolet curing device and to collect the organic coating gloss (G) measurement in at least one width portion downstream of the electron beam curing device.

[061] The gloss management tool further comprises a correction module configured to correct a deviation from the measured gloss (G) beyond the defined gloss range (Rs), the correction comprising a sub-step of calculating the correction (CT) to be applied to the wet film temperature, in at least a portion of the width downstream of the heating module and upstream of the ultraviolet curing device, taking into account (Gs) and the measured gloss (G), with a closed-loop controller and a sub-step of adjusting a coil coating line configuration, taking into account the calculated correction (CT).

[062] 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.

[063] The coil coating line is preferably Petition 870250098780, dated 10 / 29 / 2025, page 30 / 111 22 / 43 equipped with a gloss management tool to facilitate gloss management on the coil coating line.

[064] From a process standpoint, gloss management of an organic coating line formed by applying and curing a wet film of radical-curing ink on a moving strip in the coil coating 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 may be a relationship between the wet film temperature before UV curing and the gloss of the organic coating after EB curing. Consequently, any gloss deviation after EB curing can be efficiently and reproducibly corrected by adjusting the wet film temperature before UV curing.

[065] The method is applied to a moving strip. The strip may be a single coil that is 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 output of the coil coating line vary over time. The strip is moved along the path (P) of the coil coating line so that the wet film of the energy-cured ink is applied, preferably heated, and doubly cured. In particular, the strip is moved along the path (P) of the coil coating line so that the wet film of the energy-cured ink is first applied to the strip by the ink applicator, then heated by the heating module and then exposed to UV in the ultraviolet curing device and finally cured in the electron beam curing device.Optionally, the strip can be preheated with an inductor (8) positioned upstream of the ink applicator (2). Optionally, the ink can be cured by power. Petition 870250098780, dated 10 / 29 / 2025, page 31 / 111 23 / 43 can be heated in the paint applicator.

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

[067] The first step (100) of the brightness management method is to establish some defined values ​​necessary for correct regulation.

[068] The defined gloss value (Gs) of the organic coating is first 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 from the scheduling tool.

[069] As slight deviations in gloss along the length of the strip are generally acceptable from a quality standpoint, a defined gloss range (Rs) for the organic coating gloss is also defined. It can be entered as a range, with a minimum and a maximum gloss, or it can be entered as a standard deviation of the defined gloss value (Gs). Naturally, if for some reason it is necessary to avoid small deviations, 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 point of view, 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. Petition 870250098780, dated 10 / 29 / 2025, page 32 / 111 24 / 43

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

[071] Preferably, the temperature is measured with a wet-film temperature measuring device as described above and the brightness is measured with a brightness measuring device as described above.

[072] Preferably, both measurements are taken at sufficiently short time intervals to allow for adequate brightness management. Examples of time intervals are less than 30 seconds, less than 20 seconds, less than 10 seconds, less than 5 seconds, less than 2 seconds, less than 2 seconds. More preferably, both measurements are substantially continuous or continuous. Preferably, both measurements are collected at time intervals short enough to allow for adequate brightness management. Examples of time intervals are less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, less than every second. More preferably, both measurements are 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.

[073] 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 a plurality. Consequently, the wet film and the organic coating may also be conceptually divided into the same width portions. By “at least Petition 870250098780, dated 10 / 29 / 2025, p. 33 / 111 25 / 43 a width portion”, it is understood that the method is implemented on a width portion or on a plurality of width portions or on the entire width of the moving strip. In the case where it is not implemented on the entire width, it is thus possible to measure and collect: - the temperature (T) of the wet film in a single width portion if the measurement in this width portion is considered sufficiently representative of the average temperature along 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.

[074] Similarly, it is possible to measure and collect: - the gloss (G) of the organic coating in a single width portion if the measurement in this 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.

[075] In one variant, the collection step is performed after the definition step.

[076] In another variant, particularly during continuous coil coating line operation, the collection step can be performed in parallel with the settling 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 collection 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 specified gloss. Petition 870250098780, dated 10 / 29 / 2025, page 34 / 111 26 / 43 or a change in the energy-cured ink. Consequently, the setting step is performed.

[077] Preferably, in this second stage (120) of the brightness management method, the power (PW) of the heating module is also collected.

[078] In a third step (130) of the method for managing brightness, a possible deviation of the measured brightness (G) beyond the defined brightness range (Rs) is corrected. Initially, 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 will be maintained. If the measured brightness G has deviated beyond the defined brightness range (Rs), the correction (CT) to be applied to the wet film temperature in the portion of at least one width downstream of the heating module and upstream of the ultraviolet curing device is calculated, taking into account (Gs) and the measured brightness (G), with a closed-loop controller.

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

[080] The calculation of the correction (CT) to be applied to the wet film temperature 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 it. Petition 870250098780, dated 10 / 29 / 2025, page 35 / 111 27 / 43 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.

[081] Consequently, he can calculate the correction (CT) according to a general formula equation: CT(t) = ^pe(t) + Kt / 0 β(τ)άτ + Kd(5) or CT(t) = K... (e(t) +1· / β(τ)άτ + TrlU(2.) (6) 1 ί UL 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.

[082] Preferably, the correction (CT) is a function of the difference between (Gs) and the measured brightness. More preferably, the correction (CT) to be applied to the wet film temperature can be calculated according to equation 1: CT(t) = Kpei(t) + Kt£ei(T)dr + 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).

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

[084] 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 manually entered into Petition 870250098780, dated 10 / 29 / 2025, page 36 / 111 28 / 43 brightness management tool, particularly in the configuration module. They can be set during the configuration step.

[085] Alternatively, the correction (CT) to be applied to the wet film temperature can be calculated according to the following equation: CT(t) = Kp(e 1 (t) +1 / „' e 1 (τ)άτ + Td) (7) ij UL 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).

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

[087] 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.

[088] Once the correction (CT) to be applied to the wet film temperature has been calculated, a line adjustment is made taking into account the correction (CT), so that the measured brightness deviation is corrected.

[089] In a first variant illustrated in Figure 2, once the correction (CT) is calculated, the power of the heating module is adjusted so that the wet film reaches the corrected temperature Tc = T + CT in at least a portion of the width of the moving strip downstream of the heating module and upstream of the ultraviolet curing device. Adjusting the power of the heating module involves switching it on or off. Thanks to the adjustment of the heating module, the temperature of the wet film in the portion of the width downstream of the heating module and upstream of the ultraviolet curing device is corrected and a gloss value (Gs) is obtained in the organic coating in the portion Petition 870250098780, dated 10 / 29 / 2025, page 37 / 111 29 / 43 of the width downstream of the electron beam curing device. The power adjustment of the heating module can be done manually by an operator or automatically with the help of the brightness management tool, in particular the correction module.

[090] In a second variant, the correction (CP) to be applied to the heating module power is calculated 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.

[091] Consequently, the correction (CP) is a function of the correction (CT), which corresponds to a difference between the desired temperature of the wet film and the measured temperature. Preferably, the correction (CP) to be applied to the power of the heating module is calculated according to equation 2: CP(t) = K'pCT(t) + K't f*CT(rtdT + K'd^ ((2)) where K'p is the proportional gain, K'i is the integral gain, K'd is the derivative gain, and CT is the correction to be applied to the wet film temperature.

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

[093] Alternatively, the correction (CP) to be applied to the heating module power can be calculated according to the following equation: CP(t) = K'p (cT(t) +1 f0 Cr(T)dT + T·d^) (8) \ ij UL J Petition 870250098780, dated 10 / 29 / 2025, p. 38 / 111 30 / 43 where K'p is the proportional gain, T'i is the integration time, T'd is the derivation time, and CT is the correction to be applied to the wet film temperature.

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

[095] In a third variant, in the case where the coil coating line is equipped with an inductor upstream of the paint applicator, once the correction (CT) has been 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 = T + CT in at least a portion of the width of the moving strip downstream of the heating module and upstream of the ultraviolet curing device. This alternative way of correcting gloss is particularly useful in the case where the heating module is already at maximum capacity and the wet film temperature upstream of the ultraviolet curing device needs to be increased further. By further heating the strip in the inductor, the overheating to be provided by the heating module is reduced.

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

[097] In another variant, particularly during continuous coil coating line operation, the correction step can be performed in parallel with the collection 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. These can deviate the gloss. While the collection step is in progress, the correction step is performed to correct the measured gloss.

[098] Optionally, the method also includes a step (110) during which the initial conditions of the line are defined. This step is Petition 870250098780, dated 10 / 29 / 2025, page 39 / 111 31 / 43 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 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 from the appropriate line conditions to achieve the defined gloss value (Gs). In this case, the heating module may not heat adequately and / or may need 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.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 heating module needs to compensate for the altered UV dose, possibly by heating 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 the coated strip that is out of specification, it is advantageous to define 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 a process parameter is the initial line speed LS0. This is preferably the one recommended for the next roll to be coated on the roll 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 the one that corresponds to the thickness of the organic coating specified for the next roll to be coated on the Petition 870250098780, dated 10 / 29 / 2025, page 40 / 111 32 / 43 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 (S)Wd0, and the ink color. Preferably, the initial line speed LS0, the initial thickness FTh0, the initial strip thickness (S)Th0, the initial strip width (S)Wd0, and the ink color are collected. From a practical point of view, the process parameters and / or specifications can be entered manually into the gloss management tool, in particular in the configuration module. Alternatively, they can be obtained automatically from the coil coating line order book, in particular in the scheduling 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 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 heating 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 capacity of the strip, and the heating efficiency. The initial UV dose (D0) can be defined with Petition 870250098780, dated 10 / 29 / 2025, page 41 / 111 33 / 43 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.

[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 setting step (110) is performed before the setting step (100). This helps to start production with line conditions that are already optimized for the first coil of the production campaign, as well as an initial combination of defined gloss value (Gs) and defined gloss range (Rs). During production, the collection step and the correction step can be performed to manage gloss. When any of the defined parameters, in particular any of the defined gloss values ​​(Gs) and / or the defined gloss range (Rs), has to be modified for some reason, such as a change in the specified gloss or a change in the energy-cured ink, then it relies on the performance of the collection step (120) and the correction step (130) to keep the measured gloss within the defined gloss range (Rs).

[0104] In another variant, the initial line adjustment step (110) is performed after the definition step (100), as illustrated in Figure 2. In this way, the adjustment of the initial line conditions can be done taking into account the defined brightness value (Gs). The line conditions are thus better optimized for the first coil 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 brightness range Petition 870250098780, dated 10 / 29 / 2025, page 42 / 111 If the 34 / 43 defined (Rs) 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 setup 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 coil coating line operation, the initial line settling step can be performed in parallel with the collection step. In this continuous operation case, since the strip is composed of different coils connected 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 because the correction step includes additional sub-steps for: - ensure that the temperature of the wet film upstream of the UV curing device does not exceed a maximum temperature Tmax that would degrade the energy-cured ink, and - Correct the deviation of the measured brightness (G) accordingly.

[0109] Thanks to this configuration, the method also avoids thermal degradation of the wet film when heated in the heating module.

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

[0111] The definition stage (100) also includes the adjustment of Petition 870250098780, dated 10 / 29 / 2025, page 43 / 111 35 / 43 a maximum temperature (Tmax) for energy-cured ink. This temperature may be that recommended by the ink supplier. Alternatively, it may be identified by the roll coating line operator, namely by measuring the ink monomer emissions as a function of temperature, this measurement being done offline or possibly online at the heating module level. From a practical point of view, the maximum temperature (Tmax) 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 different maximum temperatures entered into the gloss management tool with the ink reference from the roll coating line order book, in particular from 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 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 UV module power and line speed and collected. The line speed itself is generally 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 calculated the Petition 870250098780, dated 10 / 29 / 2025, page 44 / 111 36 / 43 correction (CT), the sum of (T) and (CT) (referred to below as Tc) is compared to the maximum temperature Tmax. If Tc is less than Tmax, the power of the heating module is adjusted as detailed in the first embodiment.

[0115] If Tc is greater than Tmax, the gloss must be corrected without further increasing the power of the heating module or the power of the inductor, if applicable. One way to do this is to adjust the power of the UV module. In fact, it has been observed that this affects the gloss of the organic coating. The more the UV dose on the wet film increases, the more the gloss decreases. Consequently, the correction step (130) further comprises the calculation of the correction (CD) 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 3: CD = f1 (G, Gs) (3)

[0116] Equation 3 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 (f1) can therefore be derived 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. Alternatively, the function (f1) can be a PID function of the difference between (Gs) and the measured gloss (G).

[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 setting step. By “predefined” it is understood that a calibration step, preferably as described above, has been performed beforehand. Petition 870250098780, dated 10 / 29 / 2025, page 45 / 111 37 / 43 of the method implementation in the coil coating line. The function (f1) can be entered manually in the gloss management tool, especially in the configuration module. Alternatively, it can be obtained automatically by crossing the predefined mathematical relationships entered in the gloss management tool with the ink reference from the coil coating line order book, in particular from the scheduling tool.

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

[0119] Once the correction (CD) to be applied to the UV dose has been calculated, a line configuration different from the heating module power and, if applicable, the inductor power, is adjusted taking into account the calculated correction (CD), so that the measured brightness deviation is corrected.

[0120] In the variant illustrated in Figure 3, once the correction (CD) to be applied to the UV dose has been calculated, the power of the UV module is adjusted, in particular increased, 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 width portion in 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.

[0121] A third embodiment of the method is now described with reference to Figure 4.

[0122] This embodiment differs primarily from the second Petition 870250098780, dated 10 / 29 / 2025, page 46 / 111 38 / 43 because the correction phase includes additional sub-steps for: - ensure that the UV dose does not exceed the maximum UV dose Dmax to which the wet film can be exposed, - Correct the deviation of the measured brightness (G) accordingly.

[0123] Thanks to this configuration, the method also avoids over-curing of the wet film in the UV curing device, which can negatively affect the gloss.

[0124] The details provided in describing the first and second embodiments apply to the third embodiment. The additional steps and corresponding resources are described in detail now.

[0125] In this embodiment, the UV module of the coil coating line ultraviolet curing device is movable along the path (P). Consequently, the length (L) between the UV module and the electron beam curing device can be adjusted.

[0126] The definition step (100) also includes setting a maximum UV dose (Dmax) 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 maximum UV dose (Dmax) 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 maximum UV doses entered in the gloss management tool with the ink reference from the roll coating line order book, in particular from the scheduling tool.

[0127] The collection step (120) also includes collecting the length (L) between the UV module and the electron beam curing device. This length is generally known to the operator, possibly by Petition 870250098780, dated 10 / 29 / 2025, page 47 / 111 39 / 43 coating line management tool for coils. Can be collected manually. Preferably, it is collected in the gloss management tool, preferably automatically with the appropriate interface. Preferably, it is collected only when the length (L) is modified.

[0128] 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 maximum UV dose (Dmax). If Dc is less than Dmax, then 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 width portion in the UV module is corrected and a brightness value (Gs) is obtained in the organic coating in the width portion downstream of the electron beam curing device, as in the second embodiment.

[0129] If Dc is greater than Dmax, then the glossiness must be corrected without further increasing the UV dose of the UV module. One way to do this is to adjust, in particular extend, the length between the UV module and the electron beam curing device. Indeed, it has been observed that this affects the glossiness of the organic coating. The longer the time between UV curing and EB curing, the lower the glossiness. 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 4: CL = f2 (G, Gs) (4)

[0130] Equation 4 can be obtained in a calibration step performed before the correction step, preferably before the definition step. During this calibration step, the wet films of the energy-cured ink to be used in the roll coating line are exposed to Petition 870250098780, dated 10 / 29 / 2025, p. 48 / 111 40 / 43 sequential form to UV curing and EB curing under standard curing conditions with variable time between the two cures and the gloss of the organic coating is measured. The function (f2) can thus be deduced for each energy-cured ink. This calibration step can be performed once and for all and does not need to be performed each 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).

[0131] 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 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 (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 from the scheduling tool.

[0132] For example, it has been observed that for commercially available energy-curing paints for coating steel coils, f2 is generally related to a gloss curve decreasing towards an asymptote as L increases.

[0133] Once the CL correction to be applied to the length between the UV module and the electron beam curing device has been calculated, a line configuration different from the power of the heating module, different from the power of the inductor, if applicable, and different from the power of the UV module is adjusted taking into account the calculated CL correction, so that Petition 870250098780, dated 10 / 29 / 2025, page 49 / 111 41 / 43 the deviation of the measured brightness is corrected.

[0134] 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 extended, 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.

[0135] Alternatively, especially if the length between the UV module and the electron beam curing device cannot be extended or shortened further, 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 heating 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.

[0136] 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 heating device comprising a heating 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 using the ink applicator. - heating the wet film of the cured ink using energy in the heating module, - exposing the wet film of energy-cured ink to UV rays Petition 870250098780, dated 10 / 29 / 2025, page 50 / 111 42 / 43 ultraviolet curing device, - Curing the wet film of the energy-cured ink in the electron beam curing device to form the organic coating; the gloss of the organic coating is controlled by: - Define a gloss value (Gs) for the organic coating and a gloss range (Rs) for the organic coating. - collect the temperature (T) measurement of the wet film in at least one portion of the width of the moving strip upstream of the ultraviolet curing device and collect the gloss (G) measurement of the organic coating in at least one portion of the width downstream of the electron beam curing device, - Correcting a deviation from the measured gloss (G) beyond the defined gloss range (Rs), this correction step comprising a sub-step of calculating the correction (CT) to be applied to the wet film temperature, in at least a portion of the width upstream of the ultraviolet curing device, taking into account (Gs) and the measured gloss (G), with a closed-loop controller, and a sub-step of adjusting a coil coating line configuration, taking into account the calculated correction (CT).

[0137] All details provided regarding the gloss management method and all details provided regarding the coating line on coils apply to the organic coating formation method.

[0138] 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 heating device comprising a heating module, an ultraviolet curing device and a curing device. Petition 870250098780, dated 10 / 29 / 2025, page 51 / 111 43 / 43 electron beam, the method comprising the steps of: - Apply a wet film of energy-cured ink to the moving metal strip using the ink applicator. - heating the wet film of the cured ink using energy in the heating module, - Exposing the wet film of energy-cured ink to UV rays in the ultraviolet curing device, - Curing the wet film of the energy-cured ink in the electron beam curing device to form the organic coating; the gloss of the organic coating is controlled by: - Define a gloss value (Gs) for the organic coating and a gloss range (Rs) for the gloss of the organic coating. - Collect the temperature (T) measurement of the wet film on at least one portion of the width of the moving strip upstream of the ultraviolet curing device and collect the gloss (G) measurement of the organic coating on at least one portion of the width downstream of the electron beam curing device. - correct a deviation of the measured brightness (G) beyond the brightness range (Rs), this correction step being composed of a sub-step of calculating the correction (CT) to be applied to the wet film temperature, in at least a portion of the width upstream of the ultraviolet curing device, taking into account (Gs) and the measured brightness (G), with a closed-loop controller and a sub-step of adjusting the coating line in a coil, considering the calculated correction (CT). [ 0139] All details provided regarding the gloss management method and all details provided regarding the coating line on coils apply to the pre-painted metal manufacturing method. Petition 870250098780, dated 10 / 29 / 2025, page 52 / 111

Claims

1 / 5 Claims 1. METHOD 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 a coil coating line (1) comprising, sequentially along the path (P) of the moving strip, an ink applicator (2), a heating device (3) comprising a heating 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,- collect (120) the wet film temperature (T) measurement in at least one portion of the width of the moving strip 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 correction (CT) to be applied to the wet film temperature, in at least one portion of the width upstream of the ultraviolet curing device (4), considering (Gs) and the measured gloss (G), with a closed-loop controller and a sub-step of adjusting a coil coating line configuration (1), considering the calculated correction (CT)., 2. METHOD, according to claim 1, characterized in that the closed-loop controller is a proportional-integral-derivative controller.

3. METHOD, according to any of the claims Petition 870250098780, dated 10 / 29 / 2025, p. 53 / 111 2 / 5 1 to 2, characterized by the correction (CT) being a function of the difference between (Gs) and the measured brightness (G).

4. METHOD, according to any one of claims 1 to 3, characterized by the correction (CT) to be applied to the wet film temperature being calculated according to equation 1: CT(t) = Kpe1 (t) + Kt J0e1 (x)dx -1(,.-- (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 4, characterized by the substep of adjusting a coil coating line configuration (1) comprising adjusting the power of the heating module so that the wet film reaches the corrected temperature (Tc) = T + CT in at least a portion of the width of the moving strip downstream of the heating module and upstream of the ultraviolet curing device (4).

6. METHOD, according to any one of claims 1 to 4, characterized by the substep of adjusting a coil coating line configuration (1) comprising adjusting the power of the heating module by a correction (CP) calculated according to equation 2: CP(t) = K'pCT(t) + K\ J0f €T(τ)άτ + K'D ^-— (2) where K'p is the proportional gain, K'i is the integral gain, K'd is the derivative gain and (CT) is the correction to be applied to the wet film temperature.

7. METHOD, according to any one of claims 1 to 6, characterized by: - ​​the ultraviolet curing device (4) comprising a UV module, - the setting step (100) further comprising the setting of a maximum temperature (Tmax) for the energy-cured ink, - the collection step (120) further comprising the collection of the dose of Petition 870250098780, of 10 / 29 / 2025, page. 54 / 111 3 / 5 UV (D) of the UV module, - the sub-step of adjusting a coil coating line setting (1) comprises: • assessing whether T + CT is greater than Tmax, • otherwise, adjusting the power of the heating module, • if T + CT is greater than Tmax: - calculating the correction (CD) to be applied to the UV dose (D) to which the wet film in at least a portion of the width must be exposed in the UV module, according to equation 3: CD = f1 (G, Gs) (3) - adjusting a coil coating line setting (1) different from the power of the heating module, taking into account the calculated correction (CD).

8. METHOD, according to claim 7, characterized by the substep of adjusting a coil coating line configuration (1) different from the heating module power comprising 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 (D) Dc = D + CD.

9. METHOD, according to claim 7, characterized by: - ​​the UV module being mobile along the path (P), - the setting step (100) further comprising the setting of a maximum UV dose (D) (Dmax) to which the wet film can be 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 Petition 870250098780, of 10 / 29 / 2025, p.55 / 111 4 / 5 (5), - the sub-step of adjusting a coil coating line configuration (1) different from the heating module power comprises: - assessing whether D + CD is greater than Dmax, - otherwise, adjusting the UV module power so that the wet film in at least a portion of the moving strip width is exposed with the corrected UV dose (D) Dc = D + CD, - if D + CD is greater than Dmax: • calculate the correction (CL) to be applied to the length between the UV module and the electron beam curing device (5) according to equation 4: CL = f2 (G, Gs) (4) • adjust a coil coating line configuration (1) different from the heating module power and different from the UV module power, taking into account the calculated correction (CL).

10. METHOD, according to claim 9, characterized by the substep of adjusting a coil coating line configuration (1) different from the power of the heating module and different from the power of 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 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 (5).

11. METHOD, according to any one of claims 1 to 10, characterized in that the heating module is chosen from among an infrared heater, an induction heater, a convector heater, a forced-air heater, a water spray heater, a water-air mist spray heater and a heated roller.

12. COIL COATING LINE (1), characterized by sequentially comprising an ink applicator (2), a heating device (3) comprising a heating 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 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 and a defined gloss range (Rs) of the organic coating gloss,- an acquisition module that collects the wet film temperature (T) measurement in at least one width portion of the moving strip downstream of the heating module and upstream of the ultraviolet curing device (4) and collects the organic coating gloss (G) measurement in at least one width portion 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 a sub-step of calculating the correction (CT) to be applied to the wet film temperature, in at least one width portion upstream of the ultraviolet curing device (4), taking into account (Gs) and the measured gloss (G), with a closed-loop controller and a sub-step of adjusting a coil coating line configuration (1), taking into account the calculated correction (CT). Petition 870250098780, dated 10 / 29 / 2025, p. 57 / 111,

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