Method for controlling coating gloss in a coil coating line - Patent application

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 prior to 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, in one continuous process, the coil is unwound, pre-cleaned, pre-treated, pre-primed, and pre-painted before being recoiled at the other end and packaged for shipment.

[0003] The product obtained by this process is prepainted metal, also called coil coated metal, prefinished metal, or precoated metal. It is commonly used in construction applications as well as in electrical appliances.

[0004] The paints traditionally used for coil coatings are solvent-based paints. Nevertheless, there has been recent interest in radiation curing, the curing of materials using ultraviolet light (UV process) or electron beam (EB curing process). The corresponding paints, known as radcure paints, are solvent-free and the curing process is triggered either by exposure to high-energy UV light or to accelerated electrons, possibly in conjunction with a suitable photoinitiator. The photoinitiator absorbs the UV light and generates free radicals. The latter 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 the polymerization to proceed spontaneously.

[0005] One of the peculiarities 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 reach the requirements of the painted market (usually 15-30GU gloss for the architectural market), paint suppliers add matting agents as compared to solvent-based paints. However, because Radcure paints are rather viscous due to the lack of solvent, only small amounts of matting agents 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 very limited due to the speed of the curing process of Radcure paints compared to solvent-based paints (1-2 seconds vs. 12-25 seconds).

[0006] One way to alleviate this problem is known from WO81 / 00683 which discloses a curing process in which the coating is first irradiated with curing radiation at a wavelength to which the coating is responsive but has substantially no distribution below about 300 nm (such as UV), followed by 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 the gloss in an efficient and reproducible way. 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 an organic coating formed by the application and curing of a wet film of a 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 coating onto a moving strip on a coil coating line comprising, in sequence along a path P of the moving strip, a coating applicator, a heating device comprising an infrared heater, an ultraviolet curing device, and an electron beam curing device, the method comprising the steps of: - Setting gloss value G of organic coating s , setting the gloss of the organic coating gloss range R 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 over 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 over at least a portion of the width 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 From Equation 1: T c =T+K(GG s ) (1) Set the gloss range R by calculating according to s 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 ? is a sub-step of the correction step. - The correction step is the calculated correction temperature T c and adjusting the coil coating line settings to take into account the. - the method further comprises an initial line setting step; Multiple process parameters and / or strip specifications are collected; At least one initial line condition of the following is set taking into account the collected process parameters and / or strip specifications: initial power PW0 of the infrared heater, initial UV dose D0 of the UV curing device, and initial length L0 between the UV curing device and the E-beam curing device. The correction step comprises: causing the wet film to reach a correction temperature T in at least a portion of the width 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 infrared heater to reach The coil coating line further comprises an inductor upstream of the coating applicator, and the correction step comprises: causing the wet film to reach a correction 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 the Radcure paint. max The method further includes 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 is at least at a certain width of the moving strip downstream of the infrared heater and upstream of the UV curing device above the modified temperature T c adjusting the power of the infrared heater 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 calculating according to: - The correction step is the calculated corrected UV dose D c adjusting coil coating line settings other than infrared heater power to take into account. 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 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 at least in a certain width portion of the moving strip does not exceed 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 =f2(L,G,G s ) (3) According to the modified 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 and adjusting the settings of the coil coating line other than the infrared heater power and the UV module power to take 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 such that a gloss of 0.01 mm is obtained on the organic coating at least in 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 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 Temperature 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 The method includes collecting measurements of: - The correction step is 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 in the - The correction step is the calculated correction temperature T c iand adjusting the coil coating line settings to take into account the. - The fix step is to wet the film and apply the infrared heater IR i and the width portion P of the moving strip upstream of the UV curing device. i At the correction 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 form a row substantially parallel to the width of the path P. i Equipped with. - The setting step is the maximum temperature T for the Radcure paint. max The method further includes 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 limit, 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 correction 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 UV 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 the coil coating line settings other than the power. - The correction step is the width portion P of the strip to be moved 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 a 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 The method further includes setting - The collection step is the distance between the UV module and the electron beam curing device, L, L', L''...L 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 Eq. 3 i : L c i =f2(L i ,Gi ,G s ) (3) According to the UV module UV i and the modified 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 In organic coatings, UV modules are obtained i and the electron beam curing device.

[0011] A second subject of the invention consists essentially of 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 on a moving strip on the coil coating line, the gloss control tool comprising: - Setting gloss value G of organic coating s , setting the gloss of the organic coating gloss range R 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 portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device, and to collect measurements of the gloss G of the organic coating in at least a portion of the width 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 From Equation 1: T c =T+K(GG s ) (1) Set the gloss range R by calculating according to s 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 provided solely for illustrative purposes and is not intended to be in any way limiting, with reference to the figures, in which: [Brief description of the drawings]

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

[0015] It should be noted that, as used in this application, spatially related terms such as "upstream," "downstream," "lower," "upper," "above," "below," "front," "rear," and the like, refer to the locations and orientations 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, the steel strips can be bare or coated with a metal coating, either on 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% by weight aluminum, steel coated with a zinc alloy (Aluzinc®, Galvalume®) containing 55% by weight aluminum, about 1.5% by weight silicon, the remainder consisting of zinc and unavoidable impurities resulting from processing, steel coated with an aluminum alloy (Alusi®) containing 8-11% by weight silicon and 2-4% by weight iron, 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, 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, the remainder consisting of zinc and unavoidable impurities resulting from processing.

[0017] The method according to the invention is also directed to radcure coatings. The term "radcure 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 usually contain liquid monomers and oligomers in which pigments, fillers, additives, photoinitiators can be dispersed, generally without the need for either solvents or water. They are therefore substantially solvent-free.

[0018] Referring to FIG. 1, a coil coating line 1 according to the present invention mainly comprises, in order along a moving strip path P, 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 that strip S follows from its entrance in the coil coating line to its exit. 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 invention, the paint applicator 2 is a paint roll coater. It is an automatic machine that coats one or both sides of the strip with 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. There are numerous designs of paint roll coaters, depending on the configuration of the coil coating line, the type of paint used, and the type of strip to be coated. The skilled person will know which design applies best in 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 that case, a curtain of paint is applied in a horizontal strip that usually traverses 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 paint applicators include knife coaters, dip or meniscus coaters, slot coaters, meter rod coaters, and slide coaters.

[0024] The paint is typically applied to the full 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 the paint and maintaining it at a set temperature. Heating the paint facilitates its application. It also minimizes the energy requirements at the level of the infrared heaters and therefore further facilitates gloss management since it minimizes their inertia. In the case of a paint roll coater, the paint heating device can be a pan heater, i.e. a heater located in or around the paint pan. It can also be a temperature-controlled roll, in particular a temperature-controlled pick-up roll, possibly in combination with a pan heater. In the case of a curtain coater, the paint heating device can be a heater located upstream of the curtain die. It can also be a temperature-controlled backing roll, possibly in combination 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 comprises a heating device 3 equipped with an infrared heater, positioned along the path P of the moving strip downstream of the paint applicator 2 and upstream of the ultraviolet (UV) curing device 4. Its purpose is to heat the wet film of radcure paint. The heating device further improves the temperature control of the wet film of paint before its surface is cured in the UV curing device. As the temperature of the strip leaving the paint applicator decreases at a rate that depends on several parameters (nature of the strip, width of the strip, thickness of the strip, line speed, etc.), the temperature of the wet film entering the UV curing device can sometimes vary significantly, which has a negative effect on the gloss. Thanks to the infrared rays 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. The wet film is then heated uniformly along its width as it passes (passes) the infrared heater.

[0029] According to another variant, the heating device 3 comprises a number 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 in the strip width can be corrected and minimized. Preferably, the temperature variation of the wet film in the strip width at the outlet of the heating device is less than 1°C. It improves the gloss uniformity of the coating in the strip width.

[0031] According to another variant, the heating device 3 comprises a base heater and a number of infrared heaters as described above, which in turn cover the entire width of the path P along the path of the moving strip. 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 infrared heaters provides the remaining part of the energy independently and can also regulate it as required.

[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 directly heated. 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 surface cure the wet film of the radcure paint. This surface cure has been observed to produce a very fine texturing in the film surface which, in combination with intercalants and possible other charges, 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. The surface of the wet film is then 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] By virtue of 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. It 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 caused 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 installation is to cure the wet film of the radcure coating, i.e. in 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, 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 represented by 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 the gloss over the entire strip width.

[0043] Alternatively, multiple wet film temperature measuring devices are positioned downstream of the heating device 3 and upstream of the UV curing device such 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 thus preferably comprises multiple 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 and whose temperature 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, a 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 path P of the moving strip or it can measure the gloss only in a part 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 according to the standards ISO2813:2014 and EN13523-2:2021. 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, multiple gloss measuring devices are positioned downstream of the EB curing device such 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 multiple 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 in the paint applicator is convenient for paint application. 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 to unwind 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 comprise an inlet accumulator 10, if applicable, located at the inlet section of the line, downstream of the uncoiler. An accumulator is a piece of equipment that "accumulates" 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, which stores a length of metal as the two roll banks spread apart. The total stored length of metal depends on the design speed of the line, the steady state metal processing time, typically 60 seconds. Once the input section of the coil coating line is finished, the roll banks move towards 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 comprise a cleaning section 11, if applicable, located downstream of the inlet section, in particular downstream of the inlet accumulator. In this section, the strip is subjected to a surface conditioning step. This type of conditioning comprises at least one step selected among rinsing, degreasing and conversion treatment. The purpose of rinsing is to remove loose particles of dirt, potential residues of the conversion solution, soaps 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 dirt, metal particles and dirt from the surface. Preferably, degreasing is carried out in an alkaline environment. The conversion treatment comprises applying to the strip a conversion solution that makes it possible to chemically react with the surface and thus form 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 comprise 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 onto the strip to form a primer coating. The primer section may comprise a primer paint applicator and a curing facility. Depending on the nature of the primer, the curing facility may be an oven, such as a convection oven, an infrared (or near infrared) oven, or an induction oven, a UV curing device and / or an EB curing device.

[0055] The coil coating line 1 may further comprise an outlet accumulator 12 located at 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 cutoff 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 of the organic coating gloss range R 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 UV 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 further comprises a correction module configured to correct deviations of the measured gloss G beyond a correction 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 From Equation 1: T c =T+K(GG s ) (1) This includes calculating according to:

[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 standpoint, management of 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 as described above is based primarily 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 of 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 corrected in an efficient and reproducible manner by adjusting the temperature of the wet film before UV curing.

[0064] The method is applied to a moving strip. The strip can be one single coil that is unwound at the inlet of the coil coating line. More generally, the strip consists of different coils that are attached end to end to each other. The coils form one essentially continuous strip, the characteristics and technical specifications of which to be reached at the outlet of the coil coating line vary over time. The strip is moved along the path P of the coil coating line such that a wet film of radcure paint is applied, preferably heated and double cured. In particular, the strip is moved along the path P of the coil coating line such 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 in 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 the setting of any settings required for correct adjustment.

[0067] Set gloss value G of organic coating s is first set. This value corresponds to the gloss required by the customer or by the coil coating line operator. 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 setting of the organic coating is 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 a 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 Settings 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 e-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 at 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 units. o It is expressed as F / GU, or K / GU. This calibration step can be carried out only once and does not have to be carried out each time the method according to the invention is carried out.

[0071] From a practical point of view, 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 has been carried out, preferably as explained above, before the method is carried out in the coil coating line. The proportionality constant K can be manually entered into the gloss management tool, in particular into the setting 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 order book of the coil coating line, in particular from the scheduling tool.

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

[0073] In a second step 120 of the method for managing gloss, measurements are collected of the temperature T of the wet film over at least a width of the moving strip downstream of the infrared heater and upstream of the UV curing device, and measurements are collected of the gloss G of the organic coating over at least a width of the moving strip 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 a proper management of the 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, 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 a proper management of the gloss. Examples of time intervals are less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, less than every second. More preferably, both measurements are collected substantially 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" it is meant that the moving strip is conceptually divided into portions adjacent to each other within the strip width. There can be one single width portion or several. As a result, the wet film and the organic coating are also conceptually divided into the same width portion. By "at least some width portion" it is meant that the method is performed either on one width portion, or on several width portions, or on the entire width of the moving strip. If not performed on 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 over the entire strip width, or - The temperature of the wet film at multiple width portions so that the temperature at each width portion can be adjusted independently of the other portions. Likewise, it is therefore possible to measure and collect: - the gloss G of the organic coating over one single width, if the measurement over this width is considered to be 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 relative to the other sections. Details of how the gloss is controlled in that case are provided below with reference to FIG. 5.

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

[0078] In another variant, in particular during continuous operation of a coil coating line, the collection step can be carried out in parallel with the setting step. In the case of such continuous operation, changes in the strip characteristics and in the technical specifications of the strip often occur, since the strip consists of different coils that are attached end to end to each other. While the collection step is in progress, any one of the setting parameters, in particular 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 First, possible deviations of the measured gloss G that exceed the set gloss value Gs and / or the 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 100%, the correction temperature T to be reached by the wet film is determined 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 is Equation 1: T c =T+K(GG s ) (1) It is calculated according to:

[0080] The evaluation of gloss deviation can be performed at any time. Preferably, it is performed at a time interval that is 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, 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 so that the gloss value G reaches 100%. Adjusting the power of the infrared heater includes turning the infrared heater on or off. Thanks to the adjustment of 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 modified, and the gloss value G reaches 100%. s is obtained for the organic coating in a width portion downstream of the electron beam curing device. Adjustments to the infrared heater power can be made 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 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 especially 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 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, especially during continuous operation of a coil coating line, the correction step can be carried out in parallel with the collection step. In the case of such continuous operation, changes in the strip characteristics and in the technical specifications of the strip 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 carried out in order 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 type, paint thickness, paint color, or line speed, the line conditions are adjusted to a value greater than the set gloss value G. s In such a case, the infrared heater may not heat properly and / or may not reach the corrective temperature T cIt may take some time to reach the power corresponding to the set gloss value. As a result, a part of the coated strip may have to be discarded due to out-of-spec gloss. Furthermore, the UV dose to which the wet film is exposed may not be adequate to cause a surface roughness that would result in the set gloss value. In such a case, the infrared heater has to compensate for the shifted UV dose, possibly by heating more strongly, which takes time. Again, a part of the coated strip may have to be discarded due to out-of-spec gloss. It is advantageous to set the initial line conditions to minimize the length of out-of-spec coated strip.

[0088] To do so, in a first sub-step, a number of process parameters and / or specifications of the coated strip are collected. An example of a process parameter is the initial line speed LS0, which is preferably the one recommended for the next coil to be coated on the coil coating line. Another example is the initial thickness of the wet film applied to the strip by the paint applicator FTh0. 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, 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 point of view, the process parameters and / or specifications may be entered manually into the gloss management tool, in particular into the configuration module. Alternatively, they may be obtained automatically from the order book of the coil coating line, in particular from the scheduling tool, and / or may be 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 sub-step 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 constants K, helps to start production with line conditions that are already optimized for the first coil production run. During production, collection and correction steps can be performed to manage the gloss. Any one of the setting parameters, in particular 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 to a gloss range R. s 1. The method relies on execution of the collection step 120 and the correction step 130 to keep the metric within the range of 100 to 1300.

[0093] In another variant, an initial line setting step 110 is performed after the setting step 100, as shown in FIG. s The line conditions are therefore better optimized for the production run of the first coil. Furthermore, during production, any one of the setting parameters, in particular the setting gloss value G s , setting gloss range R s When any one of the constants K, , and / or the constants N needs to be modified for any reason, the initial line settings may be reconfigured 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 variant, especially during continuous operation of a coil coating line, the initial line setting step can be performed in parallel with the collection step. In the case of such continuous operation, changes in the strip characteristics and changes in the technical specifications of the strip often occur, since the strip consists of different coils that are attached end-to-end to each other. 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 modification step includes additional sub-steps to: - Calculated corrected temperature T c The maximum temperature T at which Radcure coating deteriorates max and - Correct the deviations in 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 is the maximum temperature T max This temperature may be the one recommended by the paint supplier. It may alternatively be identified by the coil coating line operator, inter alia, by measuring the emissivity of the paint monomers as a function of temperature, this measurement being performed off-line or, if possible, on-line, at the level of the infrared heaters. From a practical point of view, it is desirable to set a maximum temperature T max can be manually entered into the gloss management tool, particularly into 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 of 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. Thus, 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 of 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 are 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 is heated to 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 paint applicator, the corrected temperature is calculated so that the wet film reaches the corrected temperature T 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 it affects the gloss of organic coatings. The more the UV dose on the wet film increases, the less the gloss. As a result, 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) The method further includes calculating according to the following formula:

[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 paints to be used on a coil coating line are exposed to different UV doses and cured by 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 once and does not have to be performed every time the method according to the invention is performed.

[0106] Preferably, the function f1 of the predefined mathematical relationship between the UV dose to which the wet film of the radcure paint is exposed and the gloss of the organic coating after electron beam curing is set during a setting step. By "predefined" we mean that a calibration step has been carried out before the method is carried out in the coil coating line, preferably as described above. The function f1 can be manually entered into the gloss management tool, in particular 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 order book of the coil coating line, in particular from the scheduling tool.

[0107] For example, for commercial radcure paints for steel coil coatings, it has been observed that f1 is typically associated with a gloss curve that decreases toward 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 power of the infrared heater and, if applicable, the power of the inductor, should be set to a value G sis obtained 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.

[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 exposed 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 modified and is adjusted to a value G s A gloss of 0.01 mm is obtained on the organic coating in the width section downstream of the electron beam curing device. The adjustment of the power of the UV modules 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 modification 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 deviations in 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. It may alternatively be identified by the coil coating line operator, inter alia, 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, or 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 comprises 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 within the gloss control tool, more preferably automatically using a suitable 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 10 ... c The power / settings of the UV module are adjusted so that the wet film is exposed to a UV dose in the width portion within the UV module, as in the second embodiment, is modified to a value G sA gloss of about 100 nm 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 it 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) The method further includes calculating according to the following formula:

[0120] Equation (3) can be obtained in a calibration step carried out 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 once and does not have to be performed every time the method according to the 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, preferably as described above, has been performed before the method is implemented in the coil coating line. The function f2 can be manually entered into the gloss management tool, in particular 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 order book of the coil coating line, in particular 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 toward 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, the line settings other than the power of the infrared heater, if applicable, other than the power of the inductor, and other than the power of the UV module should be set to the value G s The calculated modified length L is calculated so that a gloss of 0.01 mm is obtained 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 such that a gloss of 0.01 mm is obtained on the organic coating at least in a width portion of the moving strip downstream of the electron beam curing device. 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 the gloss is managed for each width portion of the moving strip independently of the other portions. Thanks to this configuration, the temperature deviation along the width of the strip, which gives rise to the gloss deviation 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 are explained in detail hereinafter.

[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).

[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. In that case, each width P, P', P''...P of the moving strip downstream of the infrared heater and upstream of the UV curing device is i is one measurement T, T', T''...T at each time t. i This allocation can be done with multiple wet film temperature measuring devices, or it can be done with a single wet film temperature measuring 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 measurements of the gloss of the organic coating at multiple widths downstream of the EB curing device, where each portion P, P', P'', ... P of the moving strip downstream of the EB curing device i At each time, one measurement G, G', G''...G i This allocation can be done by multiple gloss measuring devices, or it can be done by a single gloss measuring device, for example a vibration glossmeter, that can measure the gloss of the organic coating over 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 in the measured gloss are determined by the following equation: i Set the gloss value G s and / or setting gloss range R s It is analyzed by comparing with any width part P i The gloss G measured independently of other parts i Still set gloss range R s If it is within the range, the infrared heater IR i The setting is maintained. Measured gloss G i Set the gloss range R sIf the deviation exceeds the limit, 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 ) It is calculated according to:

[0132] Any width part P i Regarding the correction step S i In the calculation of the corrected temperature, i When the temperature is 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 based on 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 The power of the power supply is adjusted. As a result, 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 forming a row substantially parallel to the width of the path P. i and collecting 120 includes collecting 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 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 of the

[0137] T c i T max , and as described in the second embodiment, the correction step 130 is i The wet film in the UV module UV 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 ) The method further includes calculating according to the following formula:

[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 set to the value G 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 is 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 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 collection 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 the maximum UV dose D max Compared to D c i D max If the UV module UV i The power of is the width of the moving strip P i The wet film in the UV module UV i UV dose D c i The specimen is adjusted so that it is exposed to

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

[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 a coating thickness of 100 nm or more 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 of PW0, PW0', PW0''...PW0 i , - UV module UV, UV', UV''...UV i Initial UV doses D0, D0', D0''...D0 i , - UV module UV, UV', UV''...UV i and the initial lengths L0, L0', L0''...L0 i .

[0147] The 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 coating to UV light 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 - Setting gloss value G of organic coating s , setting the gloss of the organic coating gloss range R 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 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; - Gloss range setting R s This correction step is managed by correcting the deviation of the measured gloss G beyond the corrected temperature T that the wet film should reach at least in a width portion downstream of the infrared heater and upstream of the UV curing device. c From 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 of 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 coating to UV light 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 - Setting gloss value G of organic coating s , setting the gloss of the organic coating gloss range R 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 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 From 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 on at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device, and collecting measurements of the gloss G of the organic coating on at least a portion of the width downstream of the electron beam curing device; - Gloss range setting R ｓ , which comprises a step of correcting the deviation of the measured gloss G beyond a 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 From equation 1: T ｃ =T+K(G-G ｓ ) (1) The method includes the sub-step of calculating according to

2. Further comprising an initial line setting step; A number of process parameters and / or strip specifications are collected; -Initial power of infrared heater PW ０ , the initial UV dose of the UV curing device D ０ , and the initial length L between the UV 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 correction step includes: causing the wet film to reach a correction temperature T in at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the ultraviolet curing device. ｃ The method of claim 1 or 2, further comprising adjusting the power of the infrared heater to reach

4. The coil coating line further includes an inductor upstream of the coating 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 The method of claim 1 or 2, further comprising adjusting the power of the inductor to reach

5. the UV curing device comprises a UV module, - The setting step is the maximum temperature T ｍａｘ and further comprising: the collecting step further comprises collecting a 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 is at 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 portion of the width of the wet film must be exposed in the UV module ｃ into 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 a 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 it exceeds , 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 determine the value G 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 moving strip downstream of the electron beam curing device on the organic coating. ｃ The method of claim 7, further comprising adjusting the

9. The heating device comprises 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 number of widths P, P', P''...P of the moving strip downstream of the infrared heater and upstream of the UV curing device. ｉ The temperatures 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 For 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 From the equation: T ｃ ｉ =T ｉ +K(G ｉ -G ｓ ) (1 ｉ ) A substep C of calculating according to ｉ The method of claim 1 , comprising:

10. The correction step is to heat the wet film by an infrared heater IR ｉ and the width portion P of the moving strip upstream of the UV curing device. ｉ At the correction temperature T ｃ ｉ In order to reach ｉ 10. The method of claim 9, further comprising adjusting the power of the

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 the radcure paint. ｍａｘ and further comprising: The collection step collects UV doses D, D', D''...D of the UV module. ｉ and collecting the - the correction step is ○ T ｃ ｉ T ｍａｘ the sub-step of evaluating whether If it does not exceed the limit, 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 correction temperature T ｃ ｉ In order to reach 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 Equation 2 ｉ : D ｃ ｉ =f １ (D ｉ ,G ｉ ,G ｓ ) (2 ｉ ) The method of claim 9 , further comprising the sub-step of calculating according to:

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

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 and collecting the - 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, the width portion P of the moving strip ｉ The wet film in the UV module UV ｉ In 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 Eq. 3 ｉ : L ｃ ｉ =f ２ (L ｉ ,G ｉ ,G ｓ ) (3) 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:

14. The correction step is to determine 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 an electron beam curing device.

15. In turn, 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 an organic coating formed by application and curing of a wet film of the 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 on at least a certain 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 on at least a certain 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 correction 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 From equation 1: T ｃ =T+K(G-G ｓ ) (1) The coil coating line includes a correction module, the correction module including:

16. The correction step is performed by calculating the calculated correction temperature T ｃ 2. 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 the calculated correction length L ｃ 8. The method of claim 7, further comprising the substep of adjusting coil coating line settings other than infrared heater power and UV module power to take into account.

19. The correction step is performed by calculating the calculated correction 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 account 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 a paint applicator; - heating a wet film of Radcure paint in an infrared heater; - exposing a wet film of Radcure coating to UV light in a UV curing device; - curing a wet film of the 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 on at least a portion of the width of the moving strip downstream of the infrared heater and upstream of the UV curing device, and collecting measurements of the gloss G of the organic coating on 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 From equation 1: T ｃ =T+K(G-G ｓ ) (1) The method includes the sub-step of calculating according to

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