Method for controlling coating gloss in a coil coating line

Abstract

The present invention relates to a method for controlling the gloss of an organic coating formed on a moving strip on a coil coating line, the method comprising: 1) a set gloss value G s , setting gloss range R s , and a proportionality constant K for a predefined linear mathematical relationship between the temperature and gloss of the wet film before UV curing; 2) collecting measurements of the temperature T of the wet film and collecting measurements of the gloss G of the wet film at least in a width portion of the moving strip upstream of the UV curing device; 3) R s , which includes a step of correcting the deviation of the measured gloss G beyond a corrected temperature T to be reached by the wet film in the width portion upstream of the UV curing device. c The equation: T c =T+K(GG s )

Description

[Technical Field]

[0001] The present invention relates to a method for controlling the gloss of an organic coating applied to a moving strip on a coil coating line, in particular the moving strip is a metal coated steel strip. [Background technology]

[0002] Coil coating is a continuous, automated process for coating metals before fabrication into a final product. Steel or aluminum substrates are delivered in coil form from a rolling mill. The metal coil is positioned at the beginning of a coil coating line, where it is unwound, pre-cleaned, pre-treated, pre-primed, and pre-painted in a continuous process before being recoiled at the other end and packaged for shipment.

[0003] The product obtained by this process is 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 electrical appliances.

[0004] The coatings traditionally used for coil coatings are solvent-based. Nevertheless, there has been recent interest in radiation curing, which involves curing materials using ultraviolet light (UV process) or electron beam (EB curing process). The corresponding coatings, known as radcure coatings, are solvent-free, and the curing process is triggered by exposure to either high-energy UV light or accelerated electrons, possibly in conjunction with a suitable photoinitiator. The photoinitiator absorbs the UV light and generates free radicals, which react with the double bonds of the monomers, causing a chain reaction and polymerization. In the case of UV-C and electron beam (EB) curing, no initiator is required. The high radiation energy creates enough reactive species (radicals) for polymerization to proceed spontaneously.

[0005] One of the unique features of Radcure paints is that they produce high-gloss organic coatings due to the high tension of the coating surface. To reduce this gloss and meet the requirements of the painted market (typically 15-30 GU for the architectural market), paint suppliers add matting agents, as opposed to solvent-based paints. However, because Radcure paints are quite viscous due to the lack of solvent, only small amounts of matting agent can be added, which does not allow for low gloss levels. In addition, the transport of matting agents to the coating surface to achieve the desired gloss level is also severely limited due to the speed of the Radcure paint curing process compared to solvent-based paints (1-2 seconds vs. 12-25 seconds).

[0006] One way to alleviate this problem is known from WO 81 / 00683, which discloses a curing process in which a coating is first irradiated with curing radiation at a wavelength to which the coating is responsive (such as UV) but has substantially no distribution below about 300 nm, and subsequently irradiated with curing radiation at a wavelength to which the coating is responsive, including substantial radiation at wavelengths below 300 nm (such as EB). This double cure is known as dual cure. Gloss control is obtained by adjusting online parameters, including the spectral distribution, intensity, or dose of the initial radiation, or the time interval between the initial and subsequent irradiation steps.

[0007] Nevertheless, it has been observed that these online parameters are not sufficient to control gloss in an efficient and reproducible manner. Summary of the Invention [Problem to be solved by the invention]

[0008] It is therefore an object of the present invention to remedy the shortcomings of the prior art processes by providing a method for efficiently and reproducibly controlling the gloss of organic coatings formed by the application and curing of a wet film of radcure paint to a moving strip on a coil coating line. [Means for solving the problem]

[0009] To this end, a first aspect of the invention is a method for managing the gloss of an organic coating formed by application and curing of a wet film of radcure paint to a moving strip on a coil coating line comprising, in sequence along a path P of the moving strip, a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the method comprising: - Gloss value G of the organic coating s , setting the gloss range R of the organic coating s and setting a proportionality constant K for a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing; - collecting measurements of the temperature T of the wet film at least in a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and collecting measurements of the gloss G of the organic coating at least in a width portion downstream of the electron beam curing device; - the corrected temperature T to be reached by the wet film at least in a width portion downstream of the infrared heater and upstream of the UV curing device; c ,Equation 1: T c =T+K(GG s ) (1) Set gloss range R by calculating according to s and correcting any deviation in the measured gloss G beyond

[0010] The method according to the invention may also have the optional features listed below, individually or in combination: - corrected temperature T c Calculating .times. ... - The correction step is the calculated correction temperature T c and further comprising the sub-step of adjusting the settings of the coil coating line to take into account: the method further comprises an initial line setting step; Multiple process parameters and / or strip specifications are collected; o At least one initial line condition of the initial power PW0 of the infrared heater, the initial UV dose D0 of the UV curing device, and the initial length L0 between the UV curing device and the electron beam curing device is set taking into account the collected process parameters and / or strip specifications. The correcting step is performed by applying a corrective temperature T c The method further includes adjusting the power of the infrared heater to reach The coil coating line further comprises an inductor upstream of the coating applicator, and the correcting step comprises: causing the wet film to reach a corrected temperature T in at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device. c The method further includes adjusting the power of the inductor to reach The ultraviolet curing device comprises a UV module. - The setting step is the maximum temperature T for Radcure paint. max and further comprising setting: The collecting step further comprises collecting a UV dose D of the UV module. - The correction steps are: 〇 T c T max the sub-step of evaluating whether If not, the wet film reaches the corrected temperature T c adjusting the power of the infrared heater so as to reach 〇 T c T max If it exceeds The corrected UV dose D that at least a certain width of the wet film must be exposed to in the UV module. c , Equation 2: D c =f1(D,G,G s ) (2) and further comprising the sub-step of calculating according to: - The correction step is the calculated corrected UV dose D c and further comprising the substep of adjusting settings of the coil coating line other than the power of the infrared heater, taking into account the above. The correcting step comprises applying a corrective UV dose D to the wet film at least in a width portion of the moving strip. c The method further includes adjusting the power of the UV module so that the UV light is exposed to the UV light. The UV module is movable along a path P. - The setting step determines the maximum UV dose D that the wet film can be exposed to in the UV module. max and further comprising setting: The collecting step further comprises collecting a length L between the UV module and the electron beam curing device. - The correction steps are: 〇 T c T max If it exceeds D c D max the sub-step of evaluating whether If the wet film in at least a certain width portion of the moving strip does not exceed the corrected UV dose D c the substep of adjusting the power of the UV module so that the UV light is exposed to D c D max If greater than , Equation 3: L c =f2(L,G,G s ) (3) According to the corrected length L between the UV module and the electron beam curing device c and further comprising the sub-step of calculating: - The correction step is the calculated corrected length L c The method further includes the substep of adjusting settings of the coil coating line other than the power of the infrared heater and the power of the UV module, taking into account the above. - The correction step is the value G s The length between the UV module and the electron beam curing device is modified to a length L such that a gloss of 0.01% or more is obtained on the organic coating in at least a width portion of the moving strip downstream of the electron beam curing device. c The method further includes adjusting the The heating device comprises a plurality of infrared heaters IR, IR', IR''...IR, which form a row substantially parallel to the width of the path P. i Equipped with. The collecting step collects a plurality of width portions P, P', P''...P of the moving strip downstream of the infrared heater and upstream of the UV curing device. i The temperatures of the wet film at T, T', T''...T i and collecting measurements of a plurality of width portions P, P', P''...P downstream of the electron beam curing device. i Gloss of organic coatings in G, G', G''...G i This includes collecting measurements of: - The correction step is to use the equation: T c i =T i +K(G i -G s ) (1 i ) According to the infrared heater IR i and a width portion P upstream of the UV curing device i The corrected temperature T to be reached by the wet film at c i By calculating i Regarding the setting gloss range R s Measured gloss exceeds G i This includes correcting deviations. - The correction step is the calculated correction temperature T c iand further comprising the sub-step of adjusting the settings of the coil coating line to take into account: - Fixation step: The wet film is heated by an infrared heater. i and the width portion P of the moving strip upstream of the UV curing device. i At the corrected temperature T c Infrared heater IR i The method further includes adjusting the power of the The UV curing device comprises a plurality of UV modules UV, UV', UV''...UV, which are arranged in rows substantially parallel to the width of the path P. i Equipped with. - The setting step is the maximum temperature T for Radcure paint. max and further comprising setting: - The collection step involves measuring the UV doses D, D', D''...D of the UV module. i The method further includes collecting the - The steps to fix it are: 〇 T c i T max the sub-step of evaluating whether If it does not exceed the temperature, the wet film is heated by the infrared heater IR. i and the width portion P of the moving strip upstream of the UV curing device. i At the corrected temperature T c i Infrared heater IR i the sub-step of adjusting the power of 〇 T c i T max If it exceeds ·Width part P i The wet film in the UV module i The corrected UV dose D must be exposed within c i , Equation 2 i : D c i =f1(D i ,G i ,G s ) (2i ) The method further includes the sub-step of calculating according to: - The correction step is the calculated corrected UV dose D c i Taking into account the infrared heater IR i adjusting settings on the coil coating line other than the power. - The correction step is the width portion P of the moving strip i The wet film at the corrected UV dose D c i UV module, so it is exposed to UV i The method further includes adjusting the power of the The UV modules are movable along the path P independently of each other. - The setting step determines the maximum UV dose D that the wet film can be exposed to in the UV module. max and further comprising setting: - The collection step is the length L, L', L''...L between the UV module and the electron beam curing device. i The method further includes collecting the - The correction steps are: 〇 T c i T max If it exceeds D c i D max the sub-step of evaluating whether If not exceeded, the width of the moving strip P i The wet film in the UV module UV i UV dose D c i UV module, so it is exposed to UV i the sub-step of adjusting the power of D c i D max If it exceeds, Equation 3 i : L c i =f2(L i ,Gi ,G s ) (3) According to the UV module UV i and the corrected length L between the electron beam curing device c i and further comprising the sub-step of calculating: - The correction step is the value G s The gloss of the width portion P downstream of the electron beam curing device i As obtained on organic coatings in UV modules UV i and the electron beam curing device.

[0011] A second subject of the invention is a coil coating line comprising a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the coil coating line further comprising a gloss control tool for controlling the gloss of the organic coating formed by the application and curing of a wet film of radcure paint to a moving strip on the coil coating line, the gloss control tool comprising: - Gloss value G of the organic coating s , setting the gloss range R of the organic coating s and a setting module configured to set a proportionality constant K of a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing; - an acquisition module configured to collect measurements of the temperature T of the wet film in at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and to collect measurements of the gloss G of the organic coating in at least a width portion downstream of the electron beam curing device; - the corrected temperature T to be reached by the wet film at least in a width portion downstream of the infrared heater and upstream of the UV curing device; c ,Equation 1: T c =T+K(GG s ) (1) Set gloss range R by calculating according to s and a correction module configured to correct deviations of the measured gloss G beyond

[0012] Other features and advantages of the present invention will be explained in more detail in the following description.

[0013] The invention will be better understood by reading the following description, which is given solely for illustrative purposes and is not intended to be limiting in any way, with reference to the figures, in which: [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of a coil coating line. [Figure 2] 1 is a flowchart of a first embodiment of the method according to the invention; [Figure 3] 4 is a flow chart of a second embodiment of the method according to the invention; [Figure 4] 4 is a flowchart of a third embodiment of the method according to the invention. [Figure 5] 4 is a flowchart of a fourth embodiment of the method according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] It should be noted that, as used in this application, spatially related terms such as "upstream," "downstream," "below," "upper," "above," "below," "front," "rear," etc., refer to the location and orientation of different components of a coil coating line.

[0016] The method according to the invention is directed to strips such as metal strips. Steel, either carbon steel or stainless steel, aluminum, copper are examples of metal strips. In particular, steel strips can be bare or coated with a metal coating on either one or both sides of the strip. Examples of potential metal-coated steels include galvanized steel, steel coated with a zinc alloy (Galfan®) containing 5% aluminum by weight, steel coated with a zinc alloy (Aluzinc®, Galvalume®) containing 55% aluminum by weight, about 1.5% silicon by weight, with the remainder consisting of zinc and unavoidable impurities resulting from processing, steel coated with an aluminum alloy (Alusi®) containing 8-11% silicon and 2-4% iron by weight, with the remainder consisting of aluminum and unavoidable impurities resulting from processing, steel coated with a layer of aluminum (Alupur®), steel coated with a zinc alloy containing 0.5-20% aluminum, 0.5-10% magnesium, with the remainder consisting of zinc and unavoidable impurities resulting from processing, and steel coated with an alloy containing aluminum, magnesium, silicon, and possibly additional elements, with the remainder consisting of zinc and unavoidable impurities resulting from processing.

[0017] The method according to the present invention is also directed to radiative cure coatings. The term "radiative cure coatings" refers to radiation-curable compositions that are "cured" or dried using short-wavelength ultraviolet (UV) light or high-energy electrons from an electron beam (EB) source. They typically contain liquid monomers and oligomers in which pigments, fillers, additives, and photoinitiators can be dispersed, generally without the need for either solvents or water. They are therefore substantially solvent-free.

[0018] Referring to FIG. 1, the coil coating line 1 according to the present invention mainly comprises, in order along the path P of the moving strip, a paint applicator 2, a heating device 3 having an infrared heater, an ultraviolet curing device 4, and an electron beam curing device 5.

[0019] Path P is the path taken by strip S from its entrance to its exit in the coil coating line. It has a width and a length. Several pieces of equipment are positioned along this path to perform operations on the strip.

[0020] The paint applicator 2 is a device that applies a wet film of paint to one or both sides of the strip with a set thickness of paint. In particular, its purpose is to apply a wet film of radcure paint. In the context of the present invention, the technology of the paint applicator is not limited.

[0021] According to a variant of the present invention, the paint applicator 2 is a paint roll coater. It is an automatic machine that coats one or both sides of a strip using a rotating roll. 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. Numerous designs of paint roll coaters exist, depending on the configuration of the coil coating line, the type of paint used, and the type of strip to be coated. Those skilled in the art will know which design best applies to each case. Generally speaking, a paint roll coater comprises a paint pan, a steel or ceramic pick-up roll, and a rubber-coated coating roll. The purpose of the paint pan is to contain, circulate, and preferably heat the paint. The pick-up roll may be partially immersed in the paint and may rotate either clockwise or counterclockwise to pick up the paint and transfer it to the coating roll. The coating roll transfers the paint to the strip.

[0022] According to another variant of the invention, the paint applicator 2 is a curtain coater. In this case, a curtain of paint is applied in a horizontal strip that typically crosses the curtain. The paint falls from a height by gravity from a curtain die or cascade while the strip is supported on a backing roller. This method makes it possible to achieve high line speeds and multi-layer coatings.

[0023] Examples of other coating applicators include knife coaters, dip or meniscus coaters, slot coaters, meter rod coaters, and slide coaters.

[0024] The paint is typically applied to the entire width of the strip using a paint applicator: by default, the width of the wet film of the paint, and consequently the width of the organic coating, is the same as the strip width.

[0025] The paint applicator 2 is preferably equipped with at least one paint heating device suitable for heating and maintaining the paint at a set temperature. Heating the paint facilitates its application. It also minimizes the energy requirements at the level of the infrared heater, thus minimizing the inertia of the infrared heater, further facilitating gloss control. In the case of a paint roll coater, the paint heating device can be a pan heater, i.e., a heater positioned in or around the paint pan. It can also be a temperature-controlled roll, in particular a temperature-controlled pick-up roll, possibly combined with a pan heater. In the case of a curtain coater, the paint heating device can be a heater positioned upstream of the curtain die. It can also be a temperature-controlled backing roll, possibly combined with a heater.

[0026] The paint applicator 2 is preferably equipped with a temperature measuring device for measuring the paint temperature and / or the wet film temperature at the level of the paint applicator. The temperature device can be, for example, a temperature sensor, a pyrometer, a thermal camera.

[0027] The coil coating line 1 further includes a heating device 3 equipped with an infrared heater positioned along the moving strip path P, downstream of the coating applicator 2 and upstream of the ultraviolet (UV) curing device 4. Its purpose is to heat the radcure coating wet film. The heating device further improves temperature control of the coating wet film before its surface is cured in the UV curing device. Because the temperature of the strip exiting the coating applicator decreases at a rate that depends on several parameters (strip properties, strip width, strip thickness, line speed, etc.), the temperature of the wet film entering the UV curing device can vary significantly, sometimes significantly, which adversely affects gloss. Thanks to the infrared radiation directly heating the wet film, the temperature of the wet film can be adjusted very quickly.

[0028] According to one variant, the infrared heater covers the entire width of the path P of the moving strip, in which case the wet film is heated uniformly along its width as it passes over the infrared heater.

[0029] According to another variant, the heating device 3 comprises a plurality of infrared heaters distributed within the width of the path P. In other words, the infrared heaters form a row substantially parallel to the width of the path P, i.e. perpendicular to the direction of movement of the strip. For the sake of clarity, the infrared heaters described herein are independent of each other and positioned adjacent to each other, but they may be physically inseparable from each other. They may be individually controllable parts of a single heating device.

[0030] Thanks to this design, the temperature variation across the strip width can be corrected and minimized. Preferably, the temperature variation across the strip width of the wet film at the exit of the heating device is less than 1°C, which improves the gloss uniformity of the coating across the strip width.

[0031] According to another variant, the heating device 3 comprises a base heater and a plurality of infrared heaters as described above, which are arranged in sequence along the path of the moving strip and cover the entire width of the path P. The base heater can be an infrared heater or an inductor. Thanks to this design, part of the energy required to reach the correct temperature of the wet film at the outlet of the heating device is provided by the base heater. Each infrared heater of the plurality of infrared heaters provides the remaining part of the energy independently and can adjust it as needed.

[0032] 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 heated directly. The heating device may also be positioned above or below the path P to minimize thermal gradients.

[0033] 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 Radcure paint wet film. This surface cure has been observed to produce a very fine texturing on the film surface, which, in combination with intercalants and possible other additives, contributes to the gloss of the organic coating once the wet film is fully cured by the electron beam.

[0034] According to one variant, the UV curing device 4 covers the entire width of the path P of the moving strip. In that case, the surface of the wet film is hardened uniformly along the width of the strip when exposed to UV.

[0035] According to another variant, the UV curing device 4 comprises a plurality of UV modules distributed within the width of the path P. In other words, the UV modules form a row substantially parallel to the width of the path P, i.e. perpendicular to the direction of movement of the strip. For the sake of clarity, the UV modules described herein are independent of each other and positioned adjacent to each other, but they may be physically inseparable from each other. They may be individually controllable parts of a single UV curing device.

[0036] Due to this design, different width portions of the path / strip can be exposed to different UV doses, which helps to correct and minimize gloss variations across the strip width.

[0037] UVA and UVB are preferred. UVA is long-range UV radiation between 320-400 nm. UVB is short-wave UV radiation between 280-320 nm. They can be obtained using conventional arc UV lamps.

[0038] The UV curing device 4 is preferably movable along the path P of the moving strip, which allows the length between the UV curing device and the EB curing device to be adjusted, i.e., extended or shortened. Indeed, it has been observed that wrinkles or surface roughness induced during UV curing are further developed during the time interval between UV and EB curing, which affects the gloss of the organic coating.

[0039] In the case of multiple UV modules, each UV module is preferably movable along the path P independently of the others.

[0040] 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 radcure coating, i.e., through its entire thickness. It further freezes the surface roughness that appears on the surface of the wet film during UV curing and that further develops during the time interval between UV and EB curing. The EB device is typically operated under the following conditions: 100-200 kV, 20-50 kGy, and inerted with nitrogen with less than 200 ppm O2.

[0041] 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 may measure the temperature of the wet film along the entire width of the moving strip path P, or it may measure the temperature of only a portion of the width. Examples of wet film temperature measuring devices include pyrometers, thermal cameras, and thermocouples. The measured temperature is expressed in °C, o It can be expressed as F or K.

[0042] If the wet film temperature measuring device measures the temperature over only a portion of the width, the measurements of this portion may be considered sufficiently relevant to control gloss over the entire strip width.

[0043] Alternatively, a plurality of wet film temperature measuring devices are positioned downstream of the heating device 3 and upstream of the UV curing device so that the entire width of the path P of the moving strip is covered. They form a row substantially parallel to the width of the path P. The heating device therefore preferably comprises a plurality of infrared heaters forming a row substantially parallel to the width of the path P, each infrared heater being suitable for heating a portion of the width of the strip, the temperature of which is measured by one wet film temperature measuring device.

[0044] To further enhance temperature control of the wet film within 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 more than 1 meter, or the temperature of the wet film is not measured for more than 4 seconds, preferably more than 2 seconds, before the wet film is cured in the UV curing device. Alternatively, or in addition, the portion of the moving strip's path P between the wet film temperature measuring device and the UV curing device may be thermally insulated to keep the wet film at the measured temperature before the wet film is cured in the UV curing device.

[0045] The coil coating line 1 further comprises a gloss measuring device 7 positioned downstream of the electron beam curing device 5. This gloss measuring device measures the gloss of the organic coating after EB curing. It can measure the gloss of the organic coating along the entire width of the moving strip path P, or it can measure the gloss over only a portion of the width. An example of a gloss measuring device is a gloss meter. The measured gloss is preferably expressed in GU (Gloss Unit). The gloss is preferably measured in accordance with standards ISO 2813:2014 and EN 13523-2:2021. Preferably, the gloss is measured in 20° geometry, 60° geometry, or 85° geometry, i.e., the reflection angle is either 20°, 60°, or 85°. More preferably, the gloss is measured in 60° geometry.

[0046] If the gloss measuring device measures the gloss over only a portion of the width, the measurements over this portion may be considered sufficiently relevant to control the gloss over the entire strip width.

[0047] Alternatively, a plurality of gloss measuring devices are positioned downstream of the EB curing device so that the entire width of the path P of the moving strip is covered. They form a row substantially parallel to the width of the path P. The heating device therefore preferably comprises a plurality of infrared heaters forming a row substantially parallel to the width of the path P, each infrared heater being suitable for heating a portion of the width of the strip, the gloss of which is measured by one gloss measuring device.

[0048] The coil coating line 1 is preferably equipped with a strip speed measuring device, more preferably located at the level of the guide rolls. An example of a strip speed measuring device is a tachymeter integrated on the roll axis.

[0049] The coil coating line 1 may further comprise an inductor 8 upstream of the paint applicator 2, which may heat the strip before it reaches the paint applicator. Having a warm strip inside the paint applicator is advantageous for coating. Furthermore, the temperature reached by the strip in the inductor may be adjusted to correct potential gloss deviations, as will be explained in more detail later.

[0050] The coil coating line 1 may further comprise an entrance section with an uncoiler 9 for unwinding the strip to be coated on the line. The uncoiler may be combined with a welding or stitching machine so that the leading end of the strip to be coated can be attached to the trailing end of the previous strip.

[0051] Alternatively, the coil coating line may be coupled to a galvanizing line so that the strip to be coated with the metal alloy contained in the bath of the galvanizing line is directly coated with the organic coating without the need to first coil it and then uncoil it.

[0052] The coil coating line 1 may further include an inlet accumulator 10, if applicable, located in the entry section of the line, downstream of the uncoiler. The accumulator is a piece of equipment that "builds up" a quantity of strip. It is a set of upper and lower banks of rolls through which the metal strip is threaded in a serpentine fashion, storing lengths of metal as the two roll banks spread apart. The total stored length of metal depends on the design speed of the line, which is typically a steady-state metal processing time of 60 seconds. Once the entry section of the coil coating line is finished, the roll banks move toward each other, and the stored metal in the accumulator continues to feed the remainder of the coil coating line.

[0053] The coil coating line 1 may further include a cleaning section 11, if applicable, located downstream of the inlet section, particularly downstream of the inlet accumulator. In this section, the strip undergoes a surface conditioning step. This type of conditioning includes at least one step selected from rinsing, degreasing, and conversion treatment. The purpose of rinsing is to remove loose particles of dirt, potential residues of the conversion solution, and any soap that may have formed, and to achieve a clean and reactive surface. The purpose of degreasing is to clean the surface by removing all traces of organic soil, metal particles, and dirt from the surface. Preferably, degreasing is carried out in an alkaline environment. The conversion treatment involves applying a conversion solution to the strip that chemically reacts with the surface, thereby forming a conversion layer. The conversion layer increases the adhesion and corrosion resistance of the paint. 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.

[0054] The coil coating line 1 may further include a primer section, if applicable, upstream of the paint roll coater and downstream of the cleaning section. In this section, a first layer of paint may be applied to the strip to form a primer coating. The primer section may include a primer paint applicator and curing equipment. Depending on the nature of the primer, the curing equipment may be an oven, such as a convection oven, an infrared (or near-infrared) oven, an induction oven, a UV curing device, and / or an EB curing device.

[0055] The coil coating line 1 may further comprise an outlet accumulator 12 located in the outlet section of the line downstream of the EB curing device. The outlet accumulator is similar to the inlet accumulator described above.

[0056] The coil coating line 1 may further comprise a recoiler 13 for recoiling the coated strip on the line. The recoiler may be combined with a cutter to separate the strip from the next strip processed on the line.

[0057] The present invention also relates to a gloss management tool for managing the gloss of an organic coating formed by application and curing of a wet film of radcure paint to a moving strip on a coil coating line comprising, in sequence along a path P of the moving strip S, a paint applicator 2, a heating device 3 comprising an infrared heater, an ultraviolet curing device 4, and an electron beam curing device 5.

[0058] The gloss management tool allows you to set gloss values ​​for organic coatings. s , setting the gloss range R of the organic coating s and a setting module for setting a proportionality constant K of a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing.

[0059] The gloss management tool further comprises an acquisition module configured to collect measurements of the temperature T of the wet film in at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and to collect measurements of the gloss G of the organic coating in at least a width portion downstream of the electron beam curing device.

[0060] The gloss management tool allows you to set the gloss range R s The correction module is configured to correct deviations of the measured gloss G beyond a corrected temperature T to be reached by the wet film downstream of the infrared heater and upstream of the UV curing device, at least in a width portion of the wet film downstream of the infrared heater and upstream of the UV curing device. c ,Equation 1: T c =T+K(GG s ) (1) This includes calculating in accordance with

[0061] The gloss management tool may include a processing unit, for example formed 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 of the setting module, the obtaining module, and the modifying module may be implemented as software executable by the processor.

[0062] The coil coating line is preferably equipped with gloss control tools to facilitate gloss control on the coil coating line.

[0063] From a processing perspective, controlling the gloss of organic coatings formed by the application and curing of a wet film of Radcure paint to a moving strip on a coil coating as described above is primarily based on the discovery that the temperature of the wet film before UV curing is important. In particular, the inventors have observed that in dual-cure coil coatings, a linear relationship exists between the temperature of the wet film before UV curing and the gloss of the organic coating after EB curing. As a result, any deviations in gloss after EB curing can be efficiently and reproducibly corrected by adjusting the temperature of the wet film before UV curing.

[0064] The method is applied to a moving strip. The strip can be a single coil unwound at the entrance of the coil coating line. More commonly, the strip consists of different coils attached end-to-end. The coils form one essentially continuous strip, the characteristics and technical specifications of which change over time to be reached at the exit of the coil coating line. The strip is moved along path P of the coil coating line so that a wet film of radcure paint is applied, preferably heated, and double-cured. In particular, the strip is moved along path P of the coil coating line so that a wet film of radcure paint is first applied to the strip by a paint applicator, then heated by an infrared heater, then exposed to UV in an ultraviolet curing device, and finally cured in an electron beam device. Optionally, the strip can be preheated by an inductor 8 located upstream of the paint applicator 2. Optionally, the radcure paint can be heated within the paint applicator.

[0065] A first embodiment of the method will be described with reference to FIG.

[0066] The first step 100 in the method for managing gloss is to set any settings required for correct adjustment.

[0067] Gloss value G of organic coating s is first set. This value corresponds to the gloss required by the customer or by the operator of the coil coating line. From a practical point of view, it can be entered manually into the gloss management tool, in particular into the settings module. Alternatively, it can be obtained automatically from the order book of the coil coating line, in particular from the scheduling tool.

[0068] Small deviations in gloss along the length of the strip are usually acceptable from a quality point of view, so the gloss of organic coatings is set within the gloss range R sIt can be entered as a range, thus with a minimum and maximum gloss, or it can be entered as a set gloss value G s Of course, if for some reason slight deviations need to be avoided, the set gloss value G s can be entered as minimum and maximum gloss, or the standard deviation can be set to zero. From a practical point of view, the set gloss range R s can be manually entered into the gloss management tool, in particular into the settings module. Alternatively, it can be obtained automatically from the management tool of the coil coating line or from the order book of the coil coating line, in particular from the scheduling tool. Gloss setting gloss range R s can also be obtained from standards such as EN10169:2013.

[0069] Also, because gloss control relies on a linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing, the proportionality constant K of this linear mathematical relationship needs to be set so that the adjustment is accurate.

[0070] The proportionality constant K can be obtained in a calibration step carried out before the setting step. During this calibration step, wet films of Radcure paint to be used on a coil coating line are heated at different temperatures and cured by double curing under standard curing conditions, and the gloss of the organic coating is measured. The proportionality constant K can then be deduced. It is preferably expressed as °C / GU, depending on the temperature unit. o It is expressed in F / GU, or K / GU. This calibration step can be performed only once and does not have to be performed each time the method according to the invention is carried out.

[0071] From a practical standpoint, the proportionality constant K is obtained from a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing, the predefined linear mathematical relationship being available to the coil coating line operator. "Predefined" means that a calibration step, as described above, has preferably been performed before the method is implemented in the coil coating line. The proportionality constant K can be manually entered into the gloss management tool, particularly into a settings module. Alternatively, it can be obtained automatically by matching the predefined linear mathematical relationship, possibly entered into the gloss management tool in the form of a table, with paint references from the coil coating line order book, particularly from a scheduling tool.

[0072] For example, it has been determined that for commercial radcure paints for steel coil coatings, K is typically comprised between 0.3 and 1.2.

[0073] In a second step 120 of the method for managing gloss, measurements of the temperature T of the wet film are collected over at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and measurements of the gloss G of the organic coating are collected over at least a width portion downstream of the electron beam curing device.

[0074] Preferably, the temperature is measured using a wet film temperature measuring device as described above, and the gloss is measured using a gloss measuring device as described above.

[0075] Preferably, both measurements are taken at a time interval short enough to have proper management of gloss. Examples of time intervals are less than 30 seconds, less than 20 seconds, less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, or less than every second. More preferably, both measurements are substantially continuous or continuous. Preferably, both measurements are collected at a time interval short enough to have proper management of gloss. Examples of time intervals are less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, or less than every second. More preferably, both measurements are collected substantially continuous or continuous. Preferably, the measurements are collected automatically within the gloss management tool, in particular within the acquisition module, more preferably using a suitable interface.

[0076] By "width portion" is meant that the moving strip is conceptually divided into portions adjacent to each other within the width of the strip. There can be one single width portion or multiple width portions. As a result, the wet film and the organic coating are also conceptually divided into the same width portions. By "at least some width portion" is meant that the method is performed either over one width portion, or multiple width portions, or the entire width of the moving strip. If not performed over the entire width, it is possible to measure and collect: - the temperature T of the wet film in one single width section, if the measurement in this width section is considered to be sufficiently representative of the average temperature across the entire strip width, or - The temperature of the wet film in multiple width sections so that the temperature in each width section can be adjusted independently of the other sections. Likewise, it is therefore possible to measure and collect: - the gloss G of the organic coating in one single width section (if the measurement in this width section is considered sufficiently relevant to control the gloss over the entire strip width), or - The gloss of the organic coating in multiple width sections, so that the gloss in each width section can be controlled independently of the other sections. Details on how gloss is controlled in that case are provided below with reference to Figure 5.

[0077] In one variation, the collecting step is performed after the setting step.

[0078] In another variant, the collection step can be carried out in parallel with the setting step, especially during continuous operation of a coil coating line. In such continuous operation, changes in the strip characteristics and technical specifications often occur, since the strip consists of different coils attached end to end to each other. While the collection step is in progress, any one of the setting parameters, especially the set gloss value G s , setting gloss range R s , and / or any one of the constants K may need to be modified for some reason, such as a change in the specified gloss or a change in the radcure paint. As a result, a setting step is performed.

[0079] In a third step 130 of the method for managing gloss, a set gloss range R s Possible deviations of the measured gloss G beyond a set gloss value Gs and / or a set gloss range R are corrected. s The measured gloss G is evaluated by comparing it with the set gloss range R. s If the measured gloss G is within the set gloss range R, the setting is maintained. s If the deviation exceeds the corrected temperature T, the corrected temperature T should be reached by the wet film at least in a width portion of the moving strip downstream of the infrared heater and upstream of the UV curing device. c is Equation 1: T c =T+K(GG s ) (1) is calculated according to

[0080] The evaluation of gloss deviation can be performed at any time. Preferably, it is performed at a time interval short enough to have adequate control of gloss. Examples of time intervals are less than 30 seconds, less than 20 seconds, less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, or less than every second. More preferably, the evaluation is substantially continuous or continuous.

[0081] Once the corrected temperature is calculated, the result of the calculation, i.e., the corrected temperature T c is preferably made available to the line operator, who can make any necessary corrections.

[0082] Generally speaking, the line setting is the value G s is obtained on the organic coating at least in a width portion of the moving strip downstream of the electron beam curing device. c In particular, the line settings are adjusted to take into account the modified temperature T c is adjusted to reach

[0083] In a first variant shown in FIG. 2, once the corrected temperature is calculated, the wet film is heated to the corrected temperature T c The power of the infrared heater is adjusted to reach the gloss value G. Adjusting the power of the infrared heater includes turning the infrared heater on or off. By adjusting the infrared heater, the temperature of the wet film in the width portion downstream of the infrared heater and upstream of the UV curing device is corrected, and the gloss value G s is obtained for the organic coating in a width portion downstream of the electron beam curing device. The adjustment of the power of the infrared heater can be done manually by an operator or automatically with the assistance of gloss management tools, particularly the correction module.

[0084] Alternatively, if the coil coating line is equipped with an inductor upstream of the paint applicator, the corrected temperature is calculated so that the wet film reaches the corrected temperature T over at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device. c The power of the inductor is adjusted so that the temperature of the strip at the level of the paint applicator is adjusted to reach . This alternative method of gloss modification is particularly useful when the infrared heater is already at maximum capacity and the temperature of the wet film upstream of the UV curing device must be further increased. By further heating the strip in the inductor, the overheating that would otherwise be provided by the infrared heater is reduced.

[0085] In one variation, the modifying step 130 is performed after the collecting step 120 .

[0086] In another variant, the correction step can be performed in parallel with the collection step, especially during continuous operation of a coil coating line. In such continuous operation, changes in the strip characteristics and technical specifications often occur, since the strip consists of different coils attached end-to-end to each other. These can cause the gloss to deviate. While the collection step is ongoing, the correction step is performed to correct the measured gloss.

[0087] Optionally, the method further comprises step 10, during which an initial line condition is set. This step is referred to as an initial line setting step. As explained above, the method includes setting a gloss range R s Any deviation in the measured gloss beyond the set gloss value G is to be corrected. That is, at the start of a production run on a coil coating line, or after a significant change, for example, in strip format, paint thickness, paint color, or line speed, the line conditions may be such that the set gloss value G s In such cases, the infrared heater may not heat properly and / or may not reach the corrected temperature T cIt may take some time to reach a power corresponding to the gloss. As a result, a portion of the coated strip may have to be discarded due to an out-of-specification gloss. Furthermore, the UV dose to which the wet film is exposed may not be appropriate to cause surface roughness that results in the set gloss value. In such cases, the infrared heater must compensate for the shifted UV dose, possibly by heating more strongly, which takes time. Again, a portion of the coated strip may have to be discarded due to an out-of-specification gloss. It is advantageous to set initial line conditions to minimize the length of out-of-specification coated strip.

[0088] To do so, in a first substep, multiple process parameters and / or specifications for the coated strip are collected. An example of a process parameter is the initial line speed LS0, which is preferably the recommended speed for the next coil to be coated on the coil coating line. Another example is the initial wet film thickness FTh0 applied to the strip by the paint applicator. The initial film thickness preferably 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 paint applicator, preferably before the inductor. Examples of specifications are the initial strip thickness STh0, the initial strip width SWd0, and the paint color. Preferably, the initial line speed LS0, the initial thickness FTh0, the initial strip thickness STh0, the initial strip width SWd0, and the paint color are collected. From a practical standpoint, the process parameters and / or specifications can be manually entered into the gloss management tool, particularly the configuration module. Alternatively, they can be automatically obtained from the coil coating line's order book, particularly from a scheduling tool, and / or inferred from the order book. For example, the initial film thickness FTh0 can be inferred from the thickness of the organic coating specified in the order book.

[0089] Once the process parameters and / or specifications have been collected, in a second substep, initial line conditions are set 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 may be set: - the initial power of the infrared heater PW0, - the initial UV dose D0 of the UV curing device or of the UV module, if applicable; - The initial length L0 between the UV curing device or UV module, if applicable, and the electron beam curing device.

[0090] The initial power PW0 can be set knowing the mass flow rate of the moving strip, the specific heat capacity of the strip, and the infrared yield. The initial UV dose D0 can be set based on data obtained in a calibration step performed before the initial line setup step. The initial length L0 can be set based on data obtained in a calibration step performed before the initial line setup step.

[0091] From a practical standpoint, the initial line conditions can be manually entered into the coil coating line management tool, or alternatively, they can be automatically populated by a gloss management tool within the coil coating line management tool.

[0092] In one variant, an initial line setting step 110 is performed before the setting step 100. It is performed by setting the gloss value G s , setting gloss range R s , and the initial combination of constant K, helps start production with line conditions already optimized for the first coil production run. During production, collection and correction steps can be performed to manage gloss. Any one of the setting parameters, particularly the set gloss value G s , setting gloss range R sWhen any one of the constants K and / or K needs to be modified for any reason, such as a change in the specified gloss or a change in the radcure paint, it sets the measured gloss within the gloss range R. s The method relies on the execution of the collection step 120 and the correction step 130 to keep the data within the range.

[0093] In another variant, an initial line setting step 110 is performed after the setting step 100, as shown in Figure 2. In this way, the setting of the initial line conditions is performed by setting the gloss value G s This can be done by taking into account the line conditions, which are therefore better optimized for the production run of the first coil. Furthermore, during production, any one of the setting parameters, in particular the set gloss value G s , setting gloss range R s When any one of the constants K, Λ, and / or the constants K needs to be modified for any reason, the initial line settings may be reset to help minimize the transition period.

[0094] In another variation, an initial line setup step 110 is performed before and after the setup step 100 to take advantage of both variations described above.

[0095] In another variation, the initial line setup step can be performed in parallel with the collection step, particularly during continuous operation of a coil coating line. In such continuous operation, changes in strip characteristics and technical specifications often occur because the strip consists of different coils that are attached end-to-end. Reinitializing the line conditions when one of these changes occurs helps to reach the set gloss value as quickly as possible.

[0096] A second embodiment of the method will now be described with reference to FIG.

[0097] This embodiment differs from the first embodiment mainly in that the modifying step includes additional sub-steps to: - calculated corrected temperature T c However, the maximum temperature T max and - Correct the deviation of the measured gloss G accordingly.

[0098] By virtue of this configuration, the method further prevents thermal degradation of the wet film when heated in the infrared heater.

[0099] The details provided when describing the first embodiment apply to the second embodiment. Additional steps and corresponding features will now be described in detail.

[0100] Setting step 100 sets the maximum temperature T max This temperature may be that recommended by the paint supplier. Alternatively, it may be identified by the coil coating line operator, inter alia, by measuring the radiation of the paint monomers as a function of temperature, this measurement being performed offline or, if possible, online at the level of the infrared heater. From a practical point of view, it is desirable to set the maximum temperature T max can be manually entered into the gloss management tool, particularly in the settings module. Alternatively, it can be obtained automatically by matching the different maximum temperatures entered into the gloss management tool with paint references from the coil coating line order book, particularly from the scheduling tool.

[0101] The collecting step 120 further includes collecting the UV dose D of the UV module. The power of the UV module is typically known from an operator, possibly from a control tool for the coil coating line, but for a given power, the actual UV dose to which the wet film is exposed varies with the line speed LS. Therefore, the UV dose is calculated and collected based on the power of the UV module and the line speed. The line speed itself is typically known from an operator, possibly from a control tool for the coil coating line.

[0102] Preferably, the UV dose is recalculated and collected each time the power of the UV module and / or the line speed is adjusted. More preferably, the collection of the UV dose is substantially continuous. Preferably, the UV dose is collected automatically within the gloss management tool, in particular within the acquisition module, more preferably using a suitable interface.

[0103] During the correction step 130, the correction temperature T c Once calculated, it is the maximum temperature T max Compared to T c T max If the temperature is below the corrected temperature T, as in the first embodiment, the wet film will reach a corrected temperature T in at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device. c Alternatively, if the coil coating line is equipped with an inductor upstream of the coating applicator, the corrected temperature is calculated so that the wet film reaches the corrected temperature T over at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device. c The power of the inductor is adjusted so that the temperature film of the strip at the level of the paint applicator is adjusted to reach

[0104] T c T max , the gloss needs to be modified without further increasing the infrared heater power or the inductor power. One way to do that is to adjust the power of the UV module. Indeed, it has been observed that this affects the gloss of organic coatings. The more the UV dose on the wet film increases, the less the gloss. Consequently, the modification step 130 determines the modified UV dose D to which the wet film in at least a certain width portion of the moving strip must be exposed in the UV module. c , Equation 2: D c =f1(D,G,G s ) (2) and further calculating according to:

[0105] Equation (2) can be obtained in a calibration step performed before the correction step, preferably before the setting step. During this calibration step, wet films of radcure paint to be used on a coil coating line are exposed to different UV doses, cured with EB at standard curing conditions, and the gloss of the organic coating is measured. Thus, the function f1 can be deduced for each radcure paint. This calibration step can be performed only once and does not need to be performed each time the method according to the present invention is performed.

[0106] Preferably, a function f1 of a predefined mathematical relationship between the UV dose to which a wet film of Radcure paint is exposed and the gloss of the organic coating after electron beam curing is set during a setup step. "Predefined" means that a calibration step, as described above, is preferably performed before the method is implemented in the coil coating line. The function f1 can be manually entered into the gloss management tool, particularly into the setup module. Alternatively, it can be obtained automatically by matching the predefined mathematical relationship entered into the gloss management tool with paint references from the coil coating line's order book, particularly from the scheduling tool.

[0107] For example, for commercial Radcure paints for steel coil coatings, f1 has been observed to be related to a gloss curve that typically decreases towards an asymptote with increasing UV dose.

[0108] Once the corrected UV dose is calculated, the result of the calculation, i.e., the corrected UV dose D c is preferably made available to the line operator, who can make any necessary corrections.

[0109] Generally speaking, the line settings other than the infrared heater power and, if applicable, the inductor power, are sa calculated modified UV dose D such that a gloss of c is adjusted taking into account.

[0110] In the variant shown in FIG. 3, once the corrected UV dose is calculated, the wet film in at least a portion of the width of the moving strip is adjusted to a UV dose D c By adjusting the UV module, the UV dose to which the wet film is exposed in the width portion within the UV module is corrected and the value G s A gloss of 0.01 mm is obtained on the organic coating in the width portion downstream of the electron beam curing device. The adjustment of the power of the UV module can be done manually by the operator or automatically with the help of a gloss management tool.

[0111] A third embodiment of the method will now be described with reference to FIG.

[0112] This embodiment differs from the second embodiment mainly in that the modifying step includes additional sub-steps to: - Calculated corrected UV dose D c is the maximum UV dose D that the wet film can be exposed to. max Ensure that it does not exceed - Correct the deviation of the measured gloss G accordingly.

[0113] By virtue of this configuration, the method further prevents over-curing of the wet film in the UV curing device, which can adversely affect gloss.

[0114] The details provided when describing the first and second embodiments apply to the third embodiment. Additional steps and corresponding features will now be described in detail.

[0115] In this embodiment, the UV module of the ultraviolet curing device of the coil coating line is movable along a path P. Thus, the length L between the UV module and the electron beam curing device can be adjusted.

[0116] The setting step 100 determines the maximum UV dose D that the wet film can be exposed to in the UV module. max This UV dose may be that recommended by the paint supplier. Alternatively, it may be identified by the coil coating line operator, especially during a calibration step. From a practical point of view, the maximum UV dose D max can be entered manually into the gloss management tool, especially in the settings module. Alternatively, it can be obtained automatically by matching the different maximum UV doses entered into the gloss management tool with paint references from the coil coating line order book, especially from the scheduling tool.

[0117] The collecting step 120 further includes collecting the length L between the UV module and the electron beam curing device. This length is typically known from an operator, possibly from a control tool of the coil coating line. It can be collected manually. Preferably, it is collected automatically within the gloss control tool, more preferably using an appropriate interface. Preferably, it is collected only when the length L is modified.

[0118] During the correction step 130, the corrected UV dose D c Once calculated, it is the maximum UV dose D max Compared to D c D max If the UV dose is less than 1000 W, the wet film in at least a certain width portion of the moving strip will be exposed to the UV dose D c The power / settings of the UV module are adjusted so that the wet film is exposed to a value G. Thanks to the adjustment of the UV module, the UV dose to which the wet film is exposed in the width portion within the UV module is modified, as in the second embodiment, to a value G. sA gloss of 0.01% is obtained on the organic coating in the width portion downstream of the electron beam curing device.

[0119] D c D max , the gloss needs to be modified without further increasing the UV dose of the UV module. One way to do that is to adjust the length between the UV module and the electron beam curing device. Indeed, it has been observed that this affects the gloss of organic coatings. The longer the time between UV curing and EB curing, the lower the gloss. As a result, the modification step 130 adjusts the modified length L between the UV module and the electron beam curing device. c , Equation 3: L c =f2(L,G,G s ) (3) and further calculating according to:

[0120] Equation (3) can be obtained in a calibration step performed before the correction step, preferably before the setting step. During this calibration step, a wet film of a radcure paint to be used on a coil coating line is successively exposed to UV and EB curing at standard curing conditions, with varying times between the two cures, and the gloss of the organic coating is measured. Thus, the function f2 can be deduced for each radcure paint. This calibration step can be performed only once and does not need to be performed each time the method according to the present invention is performed.

[0121] 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 set during a setting step. "Predefined" means that a calibration step, as described above, is preferably performed before the method is implemented in the coil coating line. The function f2 can be manually entered into the gloss management tool, particularly into the setting module. Alternatively, it can be obtained automatically by matching the predefined mathematical relationship entered into the gloss management tool with paint references from the coil coating line's order book, particularly from the scheduling tool.

[0122] For example, for commercial radcure paints for steel coil coatings, it has been observed that f2 is typically associated with a gloss curve that decreases towards an asymptote as L increases.

[0123] Once the corrected length is calculated, the result of the calculation, i.e., the corrected length L c is preferably made available to the line operator, who can make any necessary corrections.

[0124] Generally speaking, all line settings other than the infrared heater power, the inductor power if applicable, and the UV module power should be within the range of the value G s The calculated modified length L is used to obtain a gloss of 0.01 mm on the organic coating at least in a width portion of the moving strip downstream of the electron beam curing device. c is adjusted taking into account.

[0125] In the variant shown in FIG. 4, once the corrected length is calculated, the value G sThe length between the UV module and the electron beam curing device is adjusted so that a gloss of 100% is obtained on the organic coating at least in a width portion of the moving strip downstream of the electron beam curing device, and the length adjustment can be performed manually by an operator or automatically with the aid of a gloss management tool.

[0126] Alternatively, the line speed can be adjusted, especially if the length between the UV module and the electron beam curing device cannot be further increased or decreased, in which case the initial line setup is performed again to adjust the new line speed, the initial power PW0 of the infrared heater, the initial UV dose D0 of the UV curing device, and the initial length L0 between the UV curing device and the electron beam curing device.

[0127] A fourth embodiment of the method will now be described with reference to FIG. 5. This embodiment differs from the first, second, and third embodiments mainly in that gloss is managed for each width portion of the moving strip independently of the other portions. Thanks to this configuration, temperature variations along the width of the strip, which result in gloss variations along the width, can be reduced by adjusting the power of each infrared heater of the heating device independently of the other infrared heaters. The details provided when describing the first, second, and third embodiments apply to the fourth embodiment; the differences will now be explained in more detail below.

[0128] To implement the fourth embodiment of the method, the coil coating lines form rows substantially parallel to the width of the path P, hereinafter IR, IR', IR'', . . . IR i (compared to the coil coating line used to carry out the first embodiment of the method) further comprises a heating device 3 comprising a plurality of infrared heaters identified as:

[0129] In that case, the second step 120 involves collecting measurements of the temperature of the wet film at multiple widths downstream of the infrared heater and upstream of the UV curing device, where each width P, P', P''...P of the moving strip downstream of the infrared heater and upstream of the UV curing device i is one measurement T, T', T''...T at each time t. i This assignment can be done by multiple wet film temperature measurement devices, or it can be done by a single wet film temperature measurement device, such as a thermal camera, that can measure the temperature of the wet film across the entire width of the wet film.

[0130] Similarly, the second step involves collecting gloss measurements of the organic coating at multiple width portions downstream of the EB curing device, where each portion P, P', P''...P of the moving strip downstream of the EB curing device i is one measurement G, G', G''...G at each time i This assignment can be done by multiple gloss measurement devices, or it can be done by a single gloss measurement device, such as a vibration glossmeter, that can measure the gloss of the organic coating across the entire width of the organic coating.

[0131] In this embodiment, the modifying step 130 modifies the set gloss range R for each width portion independently of the others. s First, the possible deviations of the measured gloss G, G', G'', ... G i Set the gloss value G s and / or setting gloss range R s It is analyzed by comparing with the arbitrary width portion P i The gloss G measured independently of other parts i Still set gloss range R s If it is within the range, use the infrared heater IR i The setting of Measured Gloss G i Set gloss range R sIf the deviation exceeds the value, the infrared heater IR i and a width portion P upstream of the UV curing device i The corrected temperature T to be reached by the wet film at c i is Equation 1 i : T c i =T i +K(G i -G s ) (1 i ) is calculated according to

[0132] Any width part P i Regarding the correction step S i In the calculation substep C, the corrected temperature is calculated. i When calculated at c i is preferably made available to the line operator, who can make any necessary corrections.

[0133] Generally speaking, the value G s The gloss of the moving strip downstream of the electron beam curing device is i The line setting is calculated as the corrected temperature T c i is adjusted taking into account.

[0134] In the first variant shown in FIG. 5, an arbitrary width portion P i Once the corrected temperature is calculated, the wet film is heated by the infrared heater IR i and the width portion P of the moving strip upstream of the UV curing device. i At the corrected temperature T c i The line settings are adjusted so that the wet film reaches the infrared heater IR. i and a width portion P upstream of the UV curing device i At the corrected temperature T c iInfrared heater IR i As a result, the power of the value G s The gloss of the width portion P downstream of the electron beam curing device i This is obtained on an organic coating in

[0135] According to a second variant of this embodiment, the UV curing device of the coil coating line comprises a plurality of independently controllable UV modules UV, UV', UV''...UV, which form rows substantially parallel to the width of the path P. i and collecting step 120 collects UV doses D, D', D''...D of the UV modules. i The method further includes collecting the

[0136] In this modification, the arbitrary width portion P i Regarding the correction temperature T c i Once calculated, it is possible to calculate the maximum temperature T max Compared to T c i T max If the temperature is lower than 100°C, the wet film is heated by the infrared heater IR as in the first variant. i and a width portion P upstream of the UV curing device i At the corrected temperature T c i Infrared heater IR i The power is adjusted.

[0137] T c i T max , and as explained in the second embodiment, the correction step 130 is performed by adjusting the width portion P of the moving strip. i The wet film in the UV module i The corrected UV dose D must be exposed within c i , Equation 2 i : D c i =f1(D i ,G i ,G s) (2 i ) and further calculating according to:

[0138] Once the corrected UV dose is calculated, the result of the calculation, i.e., the corrected UV dose D c i is preferably made available to the line operator, who can make any necessary corrections.

[0139] Generally speaking, infrared heaters IR i The line settings other than the power of the MOSFET and, if applicable, the power of the inductor are s The gloss of the moving strip downstream of the electron beam curing device is i The corrected UV dose D calculated as obtained on the organic coating in c i is adjusted taking into account.

[0140] In this variation of the embodiment, the corrected UV dose D c i Once calculated, the UV module UV i The power of the moving strip width part P i The wet film in the UV module UV i UV dose D c i UV module, so it is exposed to UV i As a result, a gloss of value Gs is applied to a width portion P downstream of the electron beam curing device. i This is obtained on an organic coating in

[0141] According to a third variant of this embodiment, and in comparison with the second variant, each UV module is movable along a path P independently of the others, and the collecting step is performed over a length L, L', L''...L between the UV module and the electron beam curing device. i The method further includes collecting the

[0142] In this modification, the arbitrary width portion P iRegarding the corrected UV dose D c i Once calculated, it is possible to calculate the maximum UV dose D max Compared to D c i D max If the UV module UV i The power of the moving strip width part P i The wet film in the UV module UV i UV dose D c i The specimen is adjusted to be exposed to

[0143] D c i D max , the correction step 130 is performed by adjusting the UV module UV i and the corrected length L between the electron beam curing device c i , Equation 3 i : L c i =f2(L i ,G i ,G s ) (3 i ) and further calculating according to:

[0144] Once the corrected length is calculated, the result of the calculation, i.e., the corrected length L c i is preferably made available to the line operator, who can make any necessary corrections.

[0145] In this variation of the embodiment, the modified length L c i Once calculated, the UV module UV i The length between the electrode and the electron beam curing device is G s The gloss of the width portion P downstream of the electron beam curing device i The coating is adjusted to obtain the desired coating on the organic coating.

[0146] Optionally, the initial line setting step 110 differs from that described in the first embodiment in that in its second sub-step, the following initial line conditions are set taking into account the process parameters and / or specifications collected in the first sub-step: - Infrared heater IR, IR', IR''...IR i Initial power PW0, PW0', PW0''...PW0 i , - UV modules UV, UV', UV''...UV i Initial UV doses D0, D0', D0''...D0 i , - UV modules UV, UV', UV''...UV i and the electron beam curing device. i .

[0147] The present invention also relates to a method for forming an organic coating on a moving strip on a coil coating line comprising, in sequence along a path P of the moving strip, a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the method comprising: - applying a wet film of Radcure paint onto the moving strip by a paint applicator; - heating the wet film of Radcure paint in an infrared heater; - exposing the wet film of Radcure paint to UV radiation in a UV curing device; - curing the wet film of the radcure paint in an electron beam device to form an organic coating; The gloss of organic coatings is - Gloss value G of the organic coating s , setting the gloss range R of the organic coating s and setting a proportionality constant K of a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing; - collecting measurements of the temperature T of the wet film along at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and collecting measurements of the gloss G of the organic coating along at least a width portion downstream of the electron beam curing device; - Gloss range setting R s This correction step is carried out by correcting the deviation of the measured gloss G beyond the corrected temperature T that the wet film should reach downstream of the infrared heater and upstream of the UV curing device at least in a width portion thereof. c ,Equation 1: T c =T+K(GG s ) (1) The method includes the sub-step of calculating according to

[0148] All details provided in relation to the method for controlling gloss and all details provided in relation to the coil coating line apply to the method for forming the organic coating.

[0149] The method also relates to a method for producing a pre-painted metal comprising a metal strip and an organic coating on a coil coating line comprising, in sequence along a path P of the moving metal strip, a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the method comprising: - applying a wet film of Radcure paint onto the moving metal strip by a paint applicator; - heating the wet film of Radcure paint in an infrared heater; - exposing the wet film of Radcure paint to UV radiation in a UV curing device; - curing the wet film of the radcure paint in an electron beam device to form an organic coating; The gloss of organic coatings is - Gloss value G of the organic coating s , setting the gloss range R of the organic coating sand setting a proportionality constant K of a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing; - collecting measurements of the temperature T of the wet film downstream of the infrared heater and at least a width portion of the moving strip of the ultraviolet curing device, and collecting measurements of the gloss G of the organic coating downstream of the electron beam curing device; - Gloss range setting R s This correction step is carried out by correcting the deviation of the measured gloss G beyond the corrected temperature T to be reached by the wet film at least in a width portion downstream of the infrared heater and upstream of the UV curing device. c ,Equation 1: T c =T+K(GG s ) (1) The method includes the sub-step of calculating according to

[0150] All details provided in relation to the method for controlling gloss and all details provided in relation to the coil coating line apply to the method for producing pre-painted metal.

Claims

1. 1. A method for managing the gloss of an organic coating formed by application and curing of a wet film of radcure paint to a moving strip on a coil coating line comprising, in sequence along a path P of the moving strip, a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the method comprising: - set gloss value G of organic coating ｓ , the gloss setting range R of the organic coating ｓ and setting a proportionality constant K for a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing. - collecting measurements of the temperature T of the wet film in at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and collecting measurements of the gloss G of the organic coating in at least a portion of the width downstream of the electron beam curing device; - Gloss range setting R ｓ and correcting the deviation of the measured gloss G beyond a corrected temperature T to be reached by the wet film downstream of the infrared heater and upstream of the UV curing device, the correcting step comprising: ｃ , Equation 1: T ｃ =T+K(G-G ｓ ) (1) The method includes the substep of calculating according to

2. Further including an initial line setting step; A plurality of process parameters and / or strip specifications are collected; - Infrared heater initial power PW ０ , the initial UV dose of the UV curing device D ０ , and the initial length L between the ultraviolet curing device and the electron beam curing device ０ 2. The method of claim 1, wherein at least one of the initial line conditions is set taking into account collected process parameters and / or strip specifications.

3. The correcting step includes causing the wet film to reach a corrected temperature T in at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device. ｃ 3. The method of claim 1, further comprising adjusting the power of the infrared heater to reach

4. The coil coating line further includes an inductor upstream of the paint applicator, and the correcting step includes causing the wet film to reach a corrected temperature T in at least a width portion of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device. ｃ 3. The method of claim 1, further comprising adjusting the power of the inductor to reach

5. the ultraviolet curing device comprises a UV module, - The setting step is for the Radcure paint at the maximum temperature T ｍａｘ and further comprising: the collecting step further comprises collecting the UV dose D of the UV module; - The correction step is ○ T ｃ T ｍａｘ the sub-step of evaluating whether If not, the wet film reaches the corrected temperature T ｃ adjusting the power of the infrared heater to reach ○ T ｃ T ｍａｘ If it exceeds The corrected UV dose D to which at least a certain width of the wet film must be exposed in the UV module. ｃ to equation 2: D ｃ =f １ (D,G,G ｓ ) (2) The method of claim 1 or 2, further comprising the sub-step of calculating according to:

6. The correcting step comprises: applying a corrected UV dose D to the wet film at least in a width portion of the moving strip; ｃ The method of claim 5 further comprising adjusting the power of the UV module so that the UV light is exposed to

7. the UV module is movable along a path P, - the setting step determines the maximum UV dose D that the wet film can be exposed to in the UV module; ｍａｘ and further comprising: the collecting step further comprises collecting the length L between the UV module and the electron beam curing device; - The correction step is ○ T ｃ T ｍａｘ If it exceeds ・D ｃ D ｍａｘ the sub-step of evaluating whether If not, the wet film in at least a portion of the width of the moving strip is at least equal to the corrected UV dose D ｃ adjusting the power of the UV module so that the UV light is exposed to ・D ｃ D ｍａｘ If greater than , Equation 3: L ｃ =f ２ (L,G,G ｓ ) (3) According to the modified length L between the UV module and the electron beam curing device ｃ The method of claim 5 further comprising the substep of calculating:

8. The correction step is to ｓ The length between the UV module and the electron beam curing device is modified to obtain a gloss of at least a certain width portion of the organic coating on the moving strip downstream of the electron beam curing device. ｃ 8. The method of claim 7, further comprising adjusting to:

9. the heating device is a plurality of infrared heaters IR, IR', IR'', ... IR forming a row substantially parallel to the width of the path P; ｉ Equipped with The collecting step collects a plurality of width portions P, P', P''...P of the moving strip downstream of the infrared heater and upstream of the UV curing device. ｉ The temperatures of the wet film at T, T', T'', ... T ｉ and collecting measurements of a plurality of width portions P, P', P''...P downstream of the electron beam curing device. ｉ Gloss of organic coatings in G, G', G''...G ｉ collecting measurements of - The correction step is performed independently of any width portion P ｉ Regarding the setting gloss range R ｓ Measured gloss G exceeds ｉ This correction step S ｉ However, infrared heater IR ｉ and a width portion P upstream of the ultraviolet curing device ｉ The corrected temperature T to be reached by the wet film at ｃ ｉ The equation: T ｃ ｉ =T ｉ +K(G ｉ -G ｓ ) (1 ｉ ) Sub-step C of calculating according to ｉ The method of claim 1 , comprising:

10. The correction step involves heating the wet film with an infrared heater IR. ｉ and a width portion P of the moving strip upstream of the UV curing device. ｉ At the corrected temperature T ｃ ｉ Infrared heater IR ｉ 10. The method of claim 9, further comprising adjusting the power of

11. The UV curing device comprises a plurality of UV modules UV, UV', UV'', ... UV, which form a row substantially parallel to the width of the path P. ｉ Equipped with - The setting step is the maximum temperature T for Radcure paint. ｍａｘ and further comprising: The collection step involves measuring the UV doses D, D', D''...D of the UV module. ｉ further comprising collecting - The correction step is ○ T ｃ ｉ T ｍａｘ the sub-step of evaluating whether If not, the wet film is heated by the infrared heater IR. ｉ and a width portion P of the moving strip upstream of the UV curing device. ｉ At the corrected temperature T ｃ ｉ Infrared heater IR ｉ the sub-step of adjusting the power of ○ T ｃ ｉ T ｍａｘ If it exceeds ・Width part P ｉ Wet film in UV module UV ｉ The corrected UV dose D that must be exposed within ｃ ｉ , and then, Equation 2 ｉ : D ｃ ｉ =f １ (D ｉ ,G ｉ ,G ｓ ) (2 ｉ ) The method of claim 9 further comprising the substep of calculating according to:

12. The correction step is performed by dividing the width portion P of the moving strip. ｉ The wet film at the corrected UV dose D ｃ ｉ UV module UV ｉ The method of claim 11 , further comprising adjusting the power of

13. the UV modules are movable along a path P independently of one another, - the setting step determines the maximum UV dose D that the wet film can be exposed to in the UV module; ｍａｘ and further comprising: The collection step is performed over the length L, L', L''...L between the UV module and the electron beam curing device. ｉ further comprising collecting - The correction step is ○ T ｃ ｉ T ｍａｘ If it exceeds ・D ｃ ｉ D ｍａｘ the sub-step of evaluating whether If not exceeded, the width portion P of the moving strip ｉ The wet film in the UV module UV ｉ UV dose D ｃ ｉ UV module UV ｉ the sub-step of adjusting the power of ・D ｃ ｉ D ｍａｘ If it exceeds , Equation 3 ｉ : L ｃ ｉ =f ２ (L ｉ ,G ｉ ,G ｓ ) (3 i) According to UV module UV ｉ and the modified length L between the electron beam curing device ｃ ｉ The method of claim 11 further comprising the substep of calculating:

14. The correction step is to ｓ The gloss of the width portion P downstream of the electron beam curing device ｉ UV module UV ｉ The method of claim 13 , further comprising adjusting a length between the substrate and an electron beam curing device.

15. A coil coating line comprising, in order, a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the coil coating line further comprising a gloss control tool for controlling the gloss of an organic coating formed by the application and curing of a wet film of radcure paint to a moving strip on the coil coating line, the gloss control tool comprising: - set gloss value G of organic coating ｓ , the gloss setting range R of the organic coating ｓ and a setting module for setting a proportionality constant K of a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing. an acquisition module for collecting measurements of the temperature T of the wet film in at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device, and for collecting measurements of the gloss G of the organic coating in at least a portion of the width downstream of the electron beam curing device; - Gloss range setting R ｓ a correction module for correcting deviations of the measured gloss G beyond a corrected temperature T to be reached by the wet film downstream of the infrared heater and at least a certain width portion upstream of the UV curing device; ｃ , Equation 1: T ｃ =T+K(G-G ｓ ) (1) a correction module for calculating a value of the coating temperature in accordance with the formula:

16. The correction step is performed by calculating the corrected temperature T ｃ 10. The method of claim 1, further comprising the substep of adjusting coil coating line settings to take into account:

17. The correction step calculates the corrected UV dose D ｃ 6. The method of claim 5, further comprising the substep of adjusting coil coating line settings other than infrared heater power to take into account:

18. The correction step is performed by calculating the corrected length L ｃ 8. The method of claim 7, further comprising the substep of adjusting settings of the coil coating line other than the infrared heater power and the UV module power to take into account:

19. The correction step is performed by calculating the corrected temperature T ｃ ｉ 10. The method of claim 9, further comprising the substep of adjusting coil coating line settings to take into account:

20. The correction step calculates the corrected UV dose D ｃ ｉ Taking into consideration the above, the infrared heater IR ｉ 12. The method of claim 11, further comprising the substep of adjusting coil coating line settings other than power.

21. 1. A method for forming an organic coating on a moving strip on a coil coating line comprising, in sequence along a path P of the moving strip, a paint applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the method comprising: - applying a wet film of Radcure paint onto the moving strip by means of a paint applicator; - heating the wet film of Radcure paint in an infrared heater; - exposing a wet film of Radcure paint to UV light in a UV curing device; - curing a wet film of Radcure paint in an electron beam device to form an organic coating; The gloss of the organic coating - set gloss value G of organic coating ｓ , the gloss setting range R of the organic coating ｓ and setting a proportionality constant K of a predefined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing; collecting measurements of the temperature T of the wet film in at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device, and collecting measurements of the gloss G of the organic coating in at least a portion of the width downstream of the electron beam curing device; - Gloss range setting R ｓ This correction step is managed by correcting the deviation of the measured gloss G beyond the corrected temperature T to be reached by the wet film at least in a width portion downstream of the infrared heater and upstream of the UV curing device. ｃ , Equation 1: T ｃ =T+K(G-G ｓ ) (1) The method includes the substep of calculating according to

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