Method for controlling the gloss of the coating on a coil coating line

Abstract

The present invention relates to a method for controlling the gloss of an organic coating formed on a moving strip on a coil coating line, which sequentially comprises a paint applicator, a cooling device with a cooling module, an ultraviolet curing device, and an electron beam curing device, wherein the method controls the gloss within a set gloss range R s This includes correcting for deviations in the measured gloss G that exceed a certain value, and the correction is performed using a closed-loop controller, G s And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. P A sub-step to calculate the calculated correction C P The present invention relates to a method including a sub-step of adjusting the coil coating line settings with consideration to the following:

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 metal before manufacturing it into a final product. Steel or aluminum substrates are delivered from a rolling mill in coil form. The metal coil is placed at the beginning of the coil coating line, and in one continuous process, the coil is unwound, pre-cleaned, pre-treated, pre-primed, pre-painted, then wound around the other end and packaged for shipment.

[0003] The product obtained through this process is pre-coated metal, also known as coil-coated metal, pre-finished metal, or pre-coated metal. It is commonly used in building applications and fixtures.

[0004] The paints conventionally used for coil coatings are solvent-based paints. Nevertheless, recently, there has been growing interest in radiation curing, which involves curing materials using ultraviolet (UV) or electron beam (EB) curing processes. Corresponding paints, known as RadCure paints, are solvent-free, and the curing process is caused by either exposure to high-energy UV light, sometimes combined with a suitable photoinitiator, or exposure to accelerated electrons. Photoinitiators absorb UV light and generate free radicals. The latter react with the double bonds of monomers, causing chain reactions and polymerization. For UV-C and electron beam (EB) curing, initiators are not required. The high radiant energy generates enough reactive species (radicals) for polymerization to proceed spontaneously.

[0005] One of the unique characteristics of Radocure paint is that it produces an organic coating with high gloss due to the high tension of the coating surface. To reduce this gloss and meet the requirements of the pre-coating market (in the construction market, gloss is usually 15 GU to 30 GU), paint suppliers add a matting agent, as with solvent-based paints. However, because Radocure paint is very viscous due to the absence of a solvent, only a small amount of matting agent can be added, and it does not tolerate low gloss levels. Furthermore, the migration of the matting agent to the coating surface to achieve the desired gloss level is also very limited compared to solvent-based paints due to the speed of the curing process of Radocure paint (1 to 2 seconds vs. 12 to 25 seconds).

[0006] One method to mitigate this challenge is known from International Publication No. 81 / 00683, which discloses a curing process in which the coating is first irradiated with curing radiation (such as UV) at a wavelength to which the coating responds, substantially without a distribution below approximately 300 nm, and then irradiated with curing radiation (such as EB) at a wavelength to which the coating responds, substantially including wavelengths below 300 nm. This double curing is known as dual curing. Gloss control is achieved by adjusting online parameters including the spectral distribution, intensity, or dose of the initial radiation, or the time interval between the initial and subsequent irradiation steps.

[0007] Nevertheless, it has been observed that these online parameters are not sufficient to control gloss in an efficient and reproducible manner. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] International Publication No. 81 / 00683 [Overview of the project] [Problems that the invention aims to solve]

[0009] Therefore, an object of the present invention is to improve upon the shortcomings of 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 Radcure coating onto a wet film on a moving strip on a coil coating line. [Means for solving the problem]

[0010] For this purpose, the first subject of the present invention is a method for controlling the gloss of an organic coating formed by sequentially applying and curing a RadCure coating onto a wet film on a moving strip on a coil coating line, which comprises a coating applicator, a cooling device with a cooling module, an ultraviolet curing device, and an electron beam curing device, along a path P of the moving strip. - Gloss value G set for organic coating s and the set gloss range R of the organic coating s The process of setting up, - A step of collecting a measurement of the gloss G of the organic coating in at least one width portion downstream of the electron beam curing device, -Set gloss range R s A process for correcting the deviation of the measured gloss G that exceeds a certain value, wherein this correction process uses a closed-loop controller to correct the G s And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. P A sub-step to calculate the calculated correction C P A process including a sub-step of adjusting the coil coating line settings, taking into consideration, This comprises a method for controlling the gloss of an organic coating, including [specific component].

[0011] The method according to the present invention may also have the following optional features, which may be considered individually or in combination.

[0012] - The closed-loop controller is a proportional-integral-derivative controller, -Correction CP is a function of the difference between G s and the measured gloss G, and - the correction C applied to the output of the cooling module P is given by Equation 1:

[0013]

Equation

[0014] - The collection step further includes a step of collecting a measured value of the temperature T of the wet film in at least one width portion of the moving strip upstream of the ultraviolet curing device, - The correction step further includes a sub-step of calculating the corrected temperature T c reached by the wet film in at least one width portion downstream of the cooling module and upstream of the ultraviolet curing device, - The corrected temperature T c is given by Equation 2: T c = f1(T, G, G s ) (2) calculated according to, where the function f1 is a predetermined mathematical relationship between the temperature of the wet film before ultraviolet curing and the gloss of the organic coating after electron beam curing, - The corrected temperature T c is given by Equation 3: T c = T + K(G - G s ) (3) calculated according to, - The correction C P is a function of the difference between T c and the measured temperature T, - The correction C P applied to the output of the cooling module is calculated according to Equation 4,

[0015]

Equation

[0016] -This method further includes an initial line setup step, o Multiple process parameters and / or strip specifications are collected, At least one of the initial line conditions, including the initial output PW0 of the cooling module, the initial UV dose D0 of the UV curing device, and the initial length L0 between the UV curing device and the electron beam curing device, is set considering the process parameters and / or specifications of the collected strip. - The sub-process for adjusting the coil coating line settings is correction C P This includes adjusting the output of the cooling module, - The UV curing device is equipped with a UV module. - The setting process involves the minimum temperature T of the Radcure paint. min This further includes setting, - The collection process further includes the step of collecting the UV dose D of the UV module, - The sub-process for adjusting the coil coating line settings is, oT c is T min Evaluate whether it falls below this level, If it does not fall below, correct C p The output of the cooling module is adjusted accordingly. oT c is T min If it falls below: ·Formula 5: C D =f2(G,G s ) (5) Correction C is applied to the UV dose to which the wet film within at least one width portion in the UV module must be exposed. D Calculate, • Calculated correction CD Taking this into consideration, this includes adjusting the settings of the coil coating lines other than the cooling module output, - A sub-step to adjust the settings of the coil coating line other than the output of the cooling module is performed when the wet film of at least one width portion of the moving strip is corrected for UV dose D c =D+C D This includes adjusting the output of the UV module to expose it to light, - The UV module is movable along path P. - The setting process involves the minimum UV dose D to which the wet film can be exposed in the UV module. min The process further includes setting up - The collection step further includes a step of collecting the length L between the UV module and the electron beam curing device. - The sub-process of adjusting the coil coating line settings other than the output of the cooling device is, ·D+C D is D min Evaluate whether it falls below this level, If not below, the corrected UV dose D of the wet film within at least one width portion of the moving strip c =D+C D Adjust the output of the UV module so that it is exposed to the light. ·D+C D is D min If it falls below: ·Formula 6: C L =f3(G,G s ) (6) Correction C applied to the length between the UV module and the electron beam curing device according to the instructions. L Calculate, • Calculated correction C L Taking this into consideration, the process includes a sub-step to adjust the settings of the coil coating lines other than the output of the cooling module and the output of the UV module. - A sub-step adjusts the settings of the coil coating lines other than the output of the cooling module and the output of the UV module, correcting the length L between the UV module and the electron beam curing device.c =L+C L This includes adjusting to the value G s The gloss is obtained on the organic coating within at least one width portion of the moving strip downstream of the electron beam curing device. - The cooling module is selected from forced air coolers, water spray coolers, water-air spray coolers, and cooling rolls.

[0017] A second subject of the present invention is a coil coating line comprising, in sequence, a paint applicator, a cooling device with a cooling module, an ultraviolet curing device, and an electron beam curing device, wherein the coil coating line further comprises a gloss control tool for controlling the gloss of an organic coating formed by the application and curing of Radcure paint onto a wet film on a moving strip on the coil coating line, and the gloss control tool is - Gloss value G set for organic coating s and the set gloss range R of the organic coating s A configuration module for setting and - An acquisition module for collecting measurements of gloss G of an organic coating in at least one width portion downstream of an electron beam curing device, -Set gloss range R s A correction module for correcting deviations in measured gloss G that exceed a certain value, wherein the correction is performed using a closed-loop controller, G s And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. P A sub-step to calculate the calculated correction C P A correction module, which includes a sub-step for adjusting the coil coating line settings taking into consideration, It consists of a coil coating line equipped with [the following features].

[0018] Other features and advantages of the present invention will be described in more detail in the following description.

[0019] The present invention will be better understood by reading the following description. The following description is provided for illustrative purposes only and is not intended to be limiting in any way. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic diagram of the coil coating line. [Figure 2] This is a flowchart of a first embodiment of the method according to the present invention. [Figure 3] This is a flowchart of a second embodiment of the method according to the present invention. [Figure 4] This is a flowchart of a third embodiment of the method according to the present invention. [Modes for carrying out the invention]

[0021] Please note that spatially relative terms such as "upstream," "downstream," "lower," "upper," "upper," "lower," "before," "after," etc., used in this application refer to the position and orientation of different components of the coil coating line.

[0022] The method according to the present invention applies to strips such as metal strips. Examples of metal strips include steel, carbon steel, or stainless steel, as well as aluminum and copper. In particular, steel strips may be exposed or coated with a metal coating on one or both sides of the strip. Examples of possible metal-coated steels include galvanized steel, steel coated with a zinc alloy containing 5 wt% aluminum (Galfan®), steel coated with a residue consisting of 55 wt% aluminum, about 1.5 wt% silicon, zinc, and unavoidable impurities resulting from processing (Aluzinc®, Galvalume®), steel coated with aluminum containing 8-11 wt% silicon and 2-4 wt% iron, aluminum, and unavoidable impurities resulting from processing (Alusi®), steel coated with an aluminum layer (Alupur®), steel coated with a zinc alloy containing 0.5-20% aluminum and 0.5-10% magnesium, zinc, and unavoidable impurities resulting from processing, and steel coated with an alloy containing aluminum, magnesium, silicon, possible additional elements, zinc, and unavoidable impurities resulting from processing.

[0023] The methods according to the present invention also apply to Radocure coatings. The term “Radocure coating” refers to radiation-curable compositions that are “cured” or dried using short-wavelength ultraviolet (UV) light and / or high-energy electrons from an electron beam (EB) source. They typically contain liquid monomers and oligomers in which pigments, fillers, additives, and photoinitiators can be dispersed, generally without the need for a solvent or water. Therefore, they are substantially solvent-free. Radocure coatings for dual curing preferably contain acrylate or methacrylate monomers and a photoinitiator.

[0024] Referring to Figure 1, the coil coating line 1 according to the present invention mainly comprises, sequentially along the path P of a moving strip, a paint applicator 2, a cooling device 3 equipped with a cooling module, an ultraviolet curing device 4, and an electron beam curing device 5.

[0025] Path P is the path that the strip S follows within the coil coating line, from its entrance to its exit. It has a width and length. Equipment pieces are positioned along this path to perform operations on the strip.

[0026] The paint applicator 2 is a device that applies a wet film of paint to one or both sides of a strip with a set paint thickness. 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.

[0027] According to a modified embodiment of the present invention, the paint applicator 2 is a paint roll coater. This is an automated machine that coats one or both sides of a 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. Those skilled in the art will know which design best suits each case. Generally speaking, a paint roll coater comprises a paint pan, a steel or ceramic pickup roll, and a rubber-coated coating roll. The purpose of the paint pan is to contain, circulate, and preferably heat the paint. The pickup roll may be partially immersed in the paint and can rotate in either a clockwise or counterclockwise direction to pick up the paint and transfer it to the coating roll. The latter transfers the paint to the strip.

[0028] According to another variant of the present invention, the paint applicator 2 is a curtain coater. In this case, the curtain of paint is applied to horizontal strips perpendicular to the curtain. The paint falls from a height by gravity from the curtain type or cascade while the strips are supported on backing rollers. This method can achieve high line speeds and multi-layer coatings.

[0029] Other examples of paint applicators include knife coaters, dip or meniscus coaters, slot coaters, meter rod coaters, and slide coaters.

[0030] The paint is typically applied to the entire width of the strip using a paint applicator. By default, the width of the wetted film of the paint, and therefore the width of the organic coating, is the same as the width of the strip.

[0031] The paint applicator 2 preferably comprises at least one paint heating device suitable for heating the paint and maintaining it at a set temperature. Heating the paint facilitates its application. In the case of a paint roll coater, the paint heating device may be a pan heater, i.e., a heater located inside or around the paint pan. This may also be a temperature-controlled roll, particularly a temperature-controlled pickup roll, in combination with the pan heater. In the case of a curtain coater, the paint heating device may be a heater located upstream of the curtain die. It may also be a temperature-controlled backing roll, in combination with the heater.

[0032] The paint applicator 2 is preferably equipped with a temperature measuring device for measuring the paint temperature and / or wet film temperature at the paint applicator level. The temperature device may be, for example, a temperature sensor, a pyrometer, or a thermal camera.

[0033] The coil coating line 1 further comprises a cooling device 3, which includes a cooling module positioned downstream of the paint applicator 2 and upstream of the ultraviolet (UV) curing device 4 along the path P of the moving strip. Its purpose is to cool the wet film of the RadCure paint, especially when the wet film is applied onto a strip that is still warm from a previous process (e.g., curing of primer coating in an oven or galvanizing), or when the ambient temperature is warm, for example, during the summer. The cooling device further improves temperature control of the wet film of the paint before its surface is cured in the UV curing device by mitigating temperature fluctuations of the wet film entering the UV curing device that would otherwise result from line fluctuations. In fact, since the temperature of the strip leaving the paint applicator decreases at a rate that depends on numerous parameters (strip characteristics, strip width, strip thickness, line speed, ambient temperature, etc.), the temperature of the wet film entering the UV curing device can sometimes vary significantly, which negatively affects gloss. The cooling device allows the temperature of the wet film to be controlled.

[0034] The cooling device is preferably selected from a forced air cooler, a water spray cooler, a water-air spray cooler, and a cooling roll. In the case of a water-based cooler, since the wet film of the Radcure coating is applied to the upper surface of the strip, it is preferable that the water only contacts the back surface of the strip. The cooling device is not a water tank.

[0035] In one variant, the cooling device is made of a single cooling module that covers the entire width of the path P of the moving strip. In this case, as the wet film passes through the cooling device, it is cooled uniformly along its width.

[0036] In another variant, the cooling device 3 comprises multiple cooling modules distributed across the width of path P. In other words, the multiple cooling modules form rows substantially parallel to the width of path P, i.e., perpendicular to the direction of movement of the strip. For clarity, the cooling modules described herein are independent of each other and located adjacent to each other, but they may not be physically separable from one another. They may be individually controllable parts of a single cooling device.

[0037] The cooling module is preferably selected from a forced air cooler, a water spray cooler, a water-air spray cooler, and a cooling roll.

[0038] This design allows for compensation and minimization of temperature fluctuations across the strip width. Preferably, the temperature change of the wet film across the strip width at the outlet of the cooling device is less than 1°C. This improves the gloss uniformity of the coating across the strip width.

[0039] In another variant, the cooling device 3 comprises a base cooler and the aforementioned cooling modules sequentially along the path of the moving strip, covering the entire width of the path P. The base cooler can be a forced air cooler, a water spray cooler, a water-air spray cooler, and a cooling roll. Thanks to this design, part of the cooling required to reach the corrected temperature of the wet film at the outlet of the cooling device is provided by the base cooler. Each of the cooling modules independently provides the rest of the cooling, which can be adjusted as needed.

[0040] The cooling device 3 is preferably positioned above the path P so that the wet film applied to the upper surface of the strip is directly cooled. The cooling device may also be positioned above or below the path P to minimize the thermal gradient.

[0041] The coil coating line 1 further comprises an ultraviolet (UV) curing device 4. The purpose of this device is to cure the surface of the wetted film of the RadCure coating. This surface curing has been observed to produce a very fine texture on the film surface, which, in combination with a matting agent and possibly other charges, contributes to the gloss of the organic coating when the wetted film is fully cured by the electron beam.

[0042] In one variant, the UV curing device 4 covers the entire width of the path P of the moving strip. In this case, the surface of the wet film is uniformly cured along the width of the strip when exposed to UV light.

[0043] In another variant, the UV curing device 4 comprises a plurality of UV modules distributed across the width of the path P. In other words, the plurality of 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 clarity, the UV modules described herein are independent of each other and are arranged adjacent to each other, but they may not be physically separable from one another. They may be individually controllable parts of a single UV curing device.

[0044] Thanks to this design, different width portions of the path / strip can be exposed to different UV doses. This helps to compensate for and minimize gloss variations across the strip width. Therefore, the cooling device preferably comprises multiple cooling modules forming rows substantially parallel to the width of the path P, with each cooling module then suitable for cooling the width portion of the strip exposed to the UV of one UV module. In other words, each width portion covered by a particular UV module corresponds to a width portion covered by a corresponding cooling module.

[0045] UVA and UVB are preferred. UVA is long-wavelength UV radiation in the range of 320 nm to 400 nm. UVB is short-wavelength UV radiation in the range of 280 nm to 320 nm. These can be obtained with conventional arc UV lamps.

[0046] The UV curing device 4 is preferably movable along the path P of the moving strip. This allows the length between the UV curing device and the EB curing device to be adjusted, i.e., extended or shortened. It has been observed that wrinkles or surface roughness initiated during UV curing are further generated during the time interval between UV curing and EB curing, affecting the gloss of the organic coating.

[0047] In the case of multiple UV modules, it is preferable that each UV module is able to move independently along path P.

[0048] The coil coating line 1 further comprises an electron beam curing device 5. The purpose of this device is to cure the wet film of the RadCure coating, i.e., its entire thickness. It further freezes any surface roughness that appears on the surface of the wet film during UV curing and further develops during the time interval between UV curing and EB curing. The EB device is generally operated under the following conditions: 100-200kV, 20-50kGy, and deactivated with nitrogen below 200ppm O2.

[0049] Preferably, the coil coating line 1 further comprises a wet film temperature measuring device 6 located downstream of the cooling device 3 and upstream of the UV curing device 4. This wet film temperature measuring device measures the temperature of the wet film before it enters the UV curing device. It can measure the temperature of the wet film along the entire width of the path P of the moving strip, or it can measure the temperature in only a portion of the width. Examples of wet film temperature measuring devices are pyrometers, thermal cameras, and thermocouples. The measured temperature may be expressed in °C, °F, or K.

[0050] If a wet film temperature measuring device measures the temperature of only a portion of the width, the measurement of this portion may be considered sufficiently relevant to manage the gloss of the entire strip width.

[0051] Alternatively, multiple wet film temperature measuring devices are positioned downstream of the cooling device 3 and upstream of the UV curing device so as to cover the entire width of the path P of the moving strip. They form a row substantially parallel to the width of the path P. Thus, the cooling device preferably comprises multiple cooling modules forming a row substantially parallel to the width of the path P, each cooling module being suitable for cooling a width portion of the strip, the temperature of which is measured by one wet film temperature measuring device.

[0052] 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 within the UV curing device. Alternatively or additionally, a portion of the path P of the moving strip between the wet film temperature measuring device and the UV curing device may be insulated to keep the wet film at the measurement temperature before it is cured within the UV curing device.

[0053] The coil coating line 1 further comprises a gloss measuring device 7 located 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 of only a portion of the width. An example of a gloss measuring device is a gloss meter. The measured gloss is preferably expressed in GU (gloss units). The gloss is preferably measured according to ISO 2813:2014 and EN 13523-2:2021 standards. Preferably, the gloss is measured in a 20° geometric shape, a 60° geometric shape, or an 85° geometric shape, i.e., the reflection angle is one of 20°, 60°, or 85°. More preferably, the gloss is measured in a 60° geometric shape.

[0054] If a gloss measuring device measures gloss over only a portion of the width, the measurement of this portion may be considered sufficiently relevant to manage the gloss over the entire strip width.

[0055] Alternatively, multiple gloss measuring devices are positioned downstream of the EB curing device so as to cover the entire width of the path P of the moving strip. They form a row substantially parallel to the width of the path P. Thus, the cooling device preferably comprises multiple cooling modules forming a row substantially parallel to the width of the path P, each cooling module being suitable for cooling a width portion of the strip, the gloss of which is measured by one gloss measuring device. Thus, the UV curing device preferably comprises multiple UV modules forming a row substantially parallel to the width of the path P, each UV module being suitable for exposing a width portion of the strip to UV, the gloss of which is then measured by one gloss measuring device.

[0056] The coil coating line 1 is preferably equipped with a strip speed measuring device, more preferably positioned at the height of the guide roll. An example of a strip speed measuring device is a tachymeter integrated on the roll axis.

[0057] The coil coating line 1 may further include an inductor 8 upstream of the paint applicator 2. The strip can be heated before reaching the paint applicator. Having a warm strip inside the paint applicator is advantageous for painting. Furthermore, the temperature reached by the strip in the inductor can be adjusted to compensate for any possible gloss deviations, as will be described in detail later.

[0058] The coil coating line 1 may further comprise an entry section having an uncoiler 9 for unwinding strips to be coated on the line. The uncoiler may be combined with a welding or stitching machine so that the front end of the strip to be coated can be attached to the rear end of the previous strip.

[0059] Alternatively, the coil coating line can be coupled to a zinc plating line, where strips coated with a metal alloy contained in the zinc plating line bath are directly coated with the organic coating without the need to first wind the coil and then unwind it.

[0060] The coil coating line 1 may further comprise an inlet accumulator 10 located downstream of the uncoiler, in the inlet section of the line, if applicable. The accumulator is a device that "stores" a certain amount of strip. It is a set of upper and lower banks of rolls through which the metal strip is passed in a meandering manner, storing the length of metal as the two roll banks move apart. The total stored length of metal depends on the design speed of the line and is typically equivalent to 60 seconds of metalworking time in a steady state. When the inlet section of the coil coating line stops, the roll banks move toward each other, and the stored metal in the accumulator continues to feed the rest of the coil coating line.

[0061] The coil coating line 1 may further comprise a cleaning section 11 located downstream of the inlet section, particularly downstream of the inlet accumulator, where applicable. In this section, the strip is subjected to a surface preparation process. This type of preparation includes at least one step selected from rinsing, degreasing, and chemical conversion treatment. The purpose of rinsing is to remove coarse dirt particles, potential residues of the conversion solution, and any soap that may have formed, thereby achieving a clean and reactive surface. The purpose of degreasing is to clean the surface by removing all trace organic contaminants, metal particles, and dust from the surface. Preferably, degreasing is carried out in an alkaline environment. The conversion treatment involves applying a conversion solution to the strip that chemically reacts with the surface, thereby enabling the formation of a conversion layer. The latter enhances the adhesion and corrosion resistance of the coating. The chemical conversion treatment is preferably a chromium-free acidic solution. More preferably, the chemical conversion treatment is based on hexafluorotitanium acid or hexafluorozirconate.

[0062] The coil coating line 1 may further include a primer section upstream of the paint applicator 2 and downstream of the cleaning section, if applicable. In this section, a first paint layer can be applied to the strip to form a primer coating. The primer section may include a primer paint applicator and a curing device. Depending on the properties of the primer, the curing device 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.

[0063] The coil coating line 1 may further include an outlet accumulator 12 located in the outlet section of the line downstream of the EB curing device. The outlet accumulator is similar to the inlet accumulator described above.

[0064] The coil coating line 1 may further include a recoiler 13 for winding up coated strips on the line. The recoiler, in combination with a cutoff, can separate a strip from the next strip processed on the line.

[0065] The coil coating line 1 may further include a heating device positioned adjacent to the cooling device and along the path P of the moving strip. The heating device may be positioned either upstream or downstream of the cooling device. Its purpose is to substitute for the function of the cooling device when the wet film of the coating has not reached a sufficient temperature before surface curing in the UV curing device, even when the cooling device is at minimum output or stopped. Thanks to the heating device, the temperature of the wet film can be controlled more precisely than with the cooling device alone.

[0066] The heating device is preferably selected from infrared heaters, induction heaters, convection heaters, forced air heaters, water spray heaters, water-air mist spray heaters, and heating rolls. Preferably, the heating device is an infrared heater. In the case of a water-based heater, since the wet film of the Radcure coating is applied to the upper surface of the strip, it is preferable that the water comes into contact only with the back surface of the strip.

[0067] In one variant, the heating device is made of a single heating module that covers the entire width of the path P of the moving strip. In this case, as the wet film passes through the heating device, it is heated uniformly along its width.

[0068] In another variant, the heating device comprises multiple heating modules distributed across the width of the path P. In other words, the multiple heating 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 clarity, the heating modules described herein are independent of each other and arranged adjacent to each other, but they may not be physically separable from one another. They may be individually controllable parts of a single heating device.

[0069] The heating module is preferably selected from among infrared heaters, induction heaters, convection heaters, forced air heaters, water spray heaters, water-air mist spray heaters, and width portions of the heating roll. More preferably, the heating module is an infrared heater.

[0070] This design allows for compensation and minimization of temperature fluctuations across the strip width. Preferably, the temperature change of the wet film across the strip width at the outlet of the heating device is less than 1°C. This improves the gloss uniformity of the coating across the strip width.

[0071] In another variant, the heating device comprises a base heater and the aforementioned heating modules sequentially along the path of the moving strip, covering the entire width of the path P. Thanks to this design, part of the energy required to reach the corrected temperature of the wet film at the outlet of the heating device is provided by the base heater. Each of the heating modules independently provides the remaining energy, which can be adjusted as needed.

[0072] The heating device is preferably positioned above path P so that the wet film applied to the upper surface of the strip is directly heated. The heating device may also be positioned above or below path P to minimize the heat gradient.

[0073] The present invention also relates to a gloss control tool for controlling the gloss of an organic coating formed by the application and curing of RadCure paint onto a wet film on a moving strip on a coil coating line 1, comprising a paint applicator 2, a cooling device 3 with a cooling module, an ultraviolet curing device 4, and an electron beam curing device 5, arranged sequentially along a path P of the moving strip S.

[0074] The gloss management tool sets the gloss value G for organic coatings. s and the set gloss range R of the organic coating s It includes a configuration module for setting the parameters.

[0075] The gloss control tool further comprises an acquisition module configured to collect measurements of gloss G of an organic coating in at least one width portion downstream of an electron beam curing device. Preferably, the acquisition module is further configured to collect measurements of the temperature T of a wet film in at least one width portion of a moving strip downstream of a cooling module and upstream of an ultraviolet curing device.

[0076] The gloss management tool controls the set gloss range R sIt further includes a correction module configured to correct deviations in the measured gloss G that exceed G, and the correction is G s And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. P A sub-process that calculates using a closed-loop controller, and the calculated correction C P This includes a sub-step of adjusting the coil coating line settings, taking that into consideration.

[0077] The gloss management tool may include, for example, a processing unit formed by memory and a processor coupled to that memory. The electronic monitoring device may also include a display screen, each connected to the processing unit, and input / output means such as a keyboard and mouse. Each of the setting module, acquisition module, and correction module may be implemented as software executable by the processor.

[0078] The coil coating line is preferably equipped with gloss control tools to facilitate gloss control on the coil coating line.

[0079] From a process perspective, controlling the gloss of organic coatings formed by the application and curing of Radcure coatings onto a wet film on a moving strip on the coil coating line described above is primarily based on the finding that the temperature of the wet film before UV curing is crucial. In particular, the inventors observed a relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after EB curing in a dual-cure system for coil coatings. As a result, deviations in gloss after EB curing can be efficiently and reproducibly corrected by adjusting the output of the cooling module, and therefore the temperature of the wet film before UV curing.

[0080] This method is applied to a moving strip. The strip can be a single coil that is not wound at the entrance of the coil coating line. More generally, the strip consists of different coils mounted end to end to end to one another. The coils form a single essentially continuous strip, and its characteristics and the technical specifications reached at the exit of the coil coating line change over time. The strip is moved along the path P of the coil coating line so that a wet film of Radcure paint is applied, preferably cooled, and double-cured. In particular, the strip is moved along the path P of the coil coating line so that a wet film of Radcure paint is first applied onto the strip by a paint applicator, then cooled by a cooling module, then exposed to UV in an ultraviolet curing device, and finally cured in an electron beam device. Optionally, the strip may be preheated in an inductor 8 located upstream of the paint applicator 2. Optionally, the Radcure paint may be heated in the paint applicator.

[0081] A first embodiment of this method will be described with reference to Figure 2.

[0082] The first step in managing gloss is setting several parameters necessary for correction adjustment.

[0083] First, the set gloss value G for the organic coating. s This value is set. This value corresponds to the gloss level requested by the customer or the operator of the coil coating line. From a practical standpoint, this can be entered manually into a gloss management tool, particularly the settings module. Alternatively, it can be automatically obtained from the coil coating line order book, particularly from the scheduling tool.

[0084] Slight deviations in gloss along the length of the strip are usually acceptable from a quality standpoint, therefore the set gloss range R of the organic coating sThis is also set. This is a gloss value G that can be entered or set as a range that has minimum gloss and maximum gloss. s It can be entered as the standard deviation. Of course, if for some reason a small deviation must be avoided, the set gloss value G s The minimum and maximum gloss values ​​can be entered, or the standard deviation can be set to 0. From a practical standpoint, the set gloss range R s This can be manually entered in the gloss management tool, particularly in the settings module. Alternatively, it can be automatically obtained from the coil coating line management tool, or from the coil coating line order book, particularly from the scheduling tool. The set gloss range R s This can also be obtained from standards such as EN10169:2013.

[0085] In the second step 120 of the method for controlling gloss, a measurement of the gloss G of the organic coating is collected in at least one width portion downstream of the electron beam curing device.

[0086] Preferably, a measurement of the wet film temperature T in at least one width portion of the moving strip downstream of the cooling module and upstream of the UV curing device is also collected. More 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.

[0087] Preferably, measurements are taken at time intervals short enough to adequately control gloss. Examples of time intervals include less than 30 seconds, less than 20 seconds, less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, and less than every 1 second. More preferably, measurements are substantially continuous or continuous. Preferably, measurements are collected at time intervals short enough to adequately control gloss. Examples of time intervals include less than every 10 seconds, less than every 5 seconds, less than every 2 seconds, and less than every 1 second. More preferably, measurements are collected substantially continuously or continuously. Preferably, the measurements are automatically collected in a gloss control tool, particularly in an acquisition module, using a more suitable interface.

[0088] The term "width portion" means that the moving strip is conceptually divided into portions adjacent to each other in the strip width. There may be a single width portion or multiple width portions. Thus, the wet film and the organic coating may also be conceptually divided into the same width portions. The term "at least one width portion" means that the method is carried out in one width portion, multiple width portions, or the entire width of the moving strip. Therefore, if it is not carried out in the entire width, -If a measurement in a single width section is considered sufficiently relevant to control the gloss of the entire strip width, then the gloss G of the organic coating in that width section, or - The gloss of the organic coating in multiple width sections can be controlled independently of the gloss of other sections. It is possible to measure and collect them.

[0089] Similarly, -If a measurement in one single width section is considered to adequately represent the average temperature across the entire strip width, then the wet film temperature T in that width section, or - The temperature of the wet film in multiple width sections can be adjusted independently of the temperature of other sections. It is possible to measure and collect them.

[0090] In one variant configuration, the data collection process is performed after the setup process.

[0091] In another variation, the collection process may be performed in parallel with the setting process, particularly during the continuous operation of a coil coating line. In such continuous operation, since the strip consists of different coils mounted to each other from end to end, changes in the characteristics and technical specifications of the strip often occur. While the collection process is underway, one of the set parameters, in particular the set gloss value G s and / or set gloss range R sOne of these may need to be changed for some reason, such as a change in the specified gloss or a change in the Radcure paint. This will then be performed in the setup process.

[0092] Preferably, in this second step 120 of the method for controlling gloss, the output PW of the cooling module is also collected.

[0093] In the third step 130 of the method for controlling gloss, the set gloss range R s Any possible deviations in the measured gloss G that exceed a certain value are corrected. First, the measured gloss G is set to a set gloss value G. s and / or set gloss range R s By comparing it with the set gloss range R, the possible deviations in gloss are evaluated. s If within the set range, the setting will be maintained. The measured gloss G is within the set gloss range R. s If the deviation exceeds G, a closed-loop controller is used. s And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. P This is calculated.

[0094] The gloss deviation can be evaluated at any time. Preferably, it is done at time intervals short enough to adequately control 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, and less than every 1 second. More preferably, the evaluation is substantially continuous or sequential.

[0095] Correction C applied to the output of the cooling module PThe calculation is performed by a closed-loop controller. Preferably, this controller is a proportional-integral-derivative controller. In some cases, only one or two terms of the controller can provide adequate control, so some parameters of the controller can be set to 0 to disable some terms. In particular, at least one of the integral and derivative terms of the proportional-integral-derivative controller is active. "Active" means that the term is not set to 0 / is used in the calculation. That is, the proportional-integral-derivative controller is preferably a PI controller, PD controller, I controller, D controller, or PID controller.

[0096] Therefore, in particular, the general formula:

[0097]

number

[0098]

number

[0099] Correction C P In the first variant of the calculation, closed-loop control is directly based on the gloss of the organic coating. In other words, the measured process variable is the measured gloss, and the desired setpoint is G s In that case, correction C P G s This is a function of the difference between the measured gloss G and the gloss G.

[0100] In particular, the correction C applied to the output of the cooling module P Equation 1:

[0101]

Number

[0102] In particular, K i > 0 and / or K d > 0.

[0103] K p 、K i and K d Good practice rules for the initial selection of and their adjustment are well known to those skilled in the art. Therefore, K p 、K i and K d can be easily selected and adjusted as needed. The initial gains K p 、K i and K d can be manually input into the gloss management tool, particularly the setting module. These can be set during the setting process.

[0104] Alternatively, the correction C P applied to the output of the cooling module is given by the following equation:

[0105]

Number

[0106] In particular, 1 / T i > 0 and / or T d > 0.

[0107] K p 、T i and Td The rules of best practices for the initial selection and adjustment of these are well known to those skilled in the art. Therefore, K p , T i and T d These can be easily selected and adjusted as needed. Initial term K p , T i and T d These can be manually entered into the gloss management tool, particularly the settings module. They can also be configured during the setup process.

[0108] In a second variant, the collection step further includes collecting measurements of the wet film temperature T in at least one width portion of the moving strip downstream of the cooling module and upstream of the UV curing device, as it has been observed that there is a relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after EB curing, and closed-loop control of the output of the cooling module is based on the temperature of the wet film in at least one width portion downstream of the cooling module and upstream of the UV curing device. In other words, the measured process variable is the measured temperature, and the desired setpoint is a set gloss value G s To obtain this, a corrected temperature T is reached by the wet film in at least one width portion downstream of the cooling module and upstream of the UV curing device. c That is the case.

[0109] Therefore, in the first sub-step of the correction process, the corrected temperature T is reached by the wet film in at least one width portion downstream of the cooling module and upstream of the UV curing device. c This is calculated.

[0110] Generally speaking, the corrected temperature T c However, Equation 2: T c =f1(T,G,G s ) (2) The calculation is performed according to the formula, where the function f1 is a function of a predetermined mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing. "Predetermined" means that a calibration step, preferably as described below, has been performed before carrying out the method on the coil coating line.

[0111] The function f1 can be obtained in a calibration process performed before the setup process. During this calibration process, wet films of Radcure coatings used on the coil coating line are heated at different temperatures, cured by dual curing under standard curing conditions, and the gloss of the organic coating is measured. Thus, the function f1 can be derived. This calibration process only needs to be performed once and does not need to be performed each time the method according to the present invention is implemented. The function f1 can be manually entered into a gloss control tool, particularly the setup module. Alternatively, it can be obtained automatically by matching a predetermined mathematical relationship, possibly in the form of a table, entered into the gloss control tool with a coating reference from the coil coating line order book, particularly the scheduling tool. The function f1 can be set during the setup process.

[0112] In particular, some commercially available Radcure coatings for steel coil coatings use the following formula: T=T0-K G As shown by [equation], a linear mathematical relationship was observed between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing.

[0113] Here, K is the constant of proportionality.

[0114] In that case, the corrected temperature T c Equation 3: T c =T+K(GG s ) (3) It is calculated according to [the formula].

[0115] The proportionality constant K can be obtained in a calibration step performed before the setting step. During this calibration step, wet films of the Radcure coating used on the coil coating line are heated at different temperatures, cured by dual curing under standard curing conditions, and the gloss of the organic coating is measured. This allows the proportionality constant K to be derived, which is preferably expressed in °C / GU, °F / GU, or K / GU, depending on the temperature unit. This calibration step only needs to be performed once and does not need to be performed each time the method according to the present invention is implemented.

[0116] From a practical standpoint, during the correction process, the proportionality constant K is obtained from a predetermined linear mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing, and this predetermined linear mathematical relationship is available to the coil coating line operator. "Predefined" means that, preferably, the calibration process described above has been performed before implementing this method on the coil coating line. The proportionality constant K can be manually entered into a gloss control tool, particularly the setting module. Alternatively, it can be obtained automatically by matching a predetermined linear mathematical relationship, possibly in the form of a table, entered into the gloss control tool with a paint reference from the coil coating line order book, particularly the scheduling tool.

[0117] For example, in some commercially available Radcure coatings for steel coil coatings, K is typically observed to be in the range of 0.3 to 1.2. More generally, K > 0.

[0118] Corrected temperature T c Once calculated, a correction C is applied to the output of the cooling module. P is, T c It is calculated as a function of the difference between [the specified value] and the measured temperature T.

[0119] In particular, in the case of a parallel proportional-integral-derivative controller, correction C P Equation 4:

[0120]

number

[0121] In particular, K' i >0 and / or K' d >0

[0122] K' p , K' i and K' d The rules of best practices for the initial selection and adjustment of K' are well known to those skilled in the art. p , K' i and K' d This can be easily selected and adjusted as needed. Initial gain K' p , K' i and K' d These can be manually entered into the gloss management tool, particularly the settings module. They can also be configured during the setup process.

[0123] Alternatively, in the case of a standard proportional-integral-derivative controller, a correction C is applied to the output of the cooling module. P The formula is as follows:

[0124]

number

[0125] In particular, 1 / T' i >0 and / or T' d >0

[0126] K' p , T'i and T' d The rules of best practices for the initial selection and adjustment of K' are well known to those skilled in the art. p , T' i and T' d The initial term K' can be easily selected and adjusted as needed. p , T' i and T' d These can be manually entered into the gloss management tool, particularly the settings module. They can also be configured during the setup process.

[0127] Correction C P This second variation of the calculation, as will be explained in detail later, avoids the juxtaposition of interdependent closed-loop controls and ensures that the temperature of the wet film is at the lowest temperature T that will prevent the Radcure coating from reacting when exposed to UV. min It is very useful for controlling the level so that it does not fall below a certain point.

[0128] Correction C applied to the output of the cooling module P Once calculated, the correction C is applied so that the deviation of the measured gloss is corrected. P The line settings are adjusted taking this into consideration.

[0129] In particular, Correction C p Once calculated, the output of the cooling module is corrected C p This is adjusted by adjusting the output of the cooling module, which includes turning the cooling module on or off. By adjusting the cooling module, the temperature of the wet film in the width portion downstream of the cooling module and upstream of the UV curing device is corrected, and a value G is applied to the organic coating in the width portion downstream of the electron beam curing device. s This gloss is achieved. The output of the cooling module can be adjusted manually by the operator or automatically with the help of gloss management tools, especially the correction module.

[0130] Alternatively, if the coil coating line includes a heating module and is equipped with a heating device adjacent to the cooling device, then correction C pOnce calculated, the heating module is turned on, its power is adjusted, and the organic coating of at least one width portion of the moving flow downstream of the electron beam curing device is set to value G s This gloss is obtained. Correction C p The corrected temperature T before calculation c If calculated, the output of the heating module is adjusted so that the wet film reaches a corrected temperature Tc in at least the width portion of the moving strip downstream of the cooling / heating module and upstream of the UV curing device. This alternative method of correcting gloss is particularly useful when the cooling module is already at minimum capacity or off and the temperature of the wet film upstream of the UV curing device must be further increased.

[0131] Alternatively, if the coil coating line is equipped with an inductor upstream of the paint applicator, a correction C is applied. p Once calculated, the inductor output is adjusted to control the temperature of the strip at the level of the paint applicator, thereby controlling the value G. s The gloss is obtained on the organic coating of at least one width portion of the moving flow downstream of the electron beam curing device. Corrected temperature T c Correction C p If calculated beforehand, the inductor output is adjusted so that the wet film reaches a corrected temperature Tc in at least one width portion of the moving strip downstream of the cooling module / heating module and upstream of the UV curing device. This alternative method of correcting gloss is particularly useful when the cooling module is already at minimum capacity or off and the temperature of the wet film upstream of the UV curing device must be further increased.

[0132] In one variant, the correction step 130 is performed after the acquisition step 120.

[0133] In another variation, the correction process may be performed in parallel with the collection process, particularly during the continuous operation of a coil coating line. In such continuous operation, since the strip consists of different coils mounted to each other from end to end, changes in the characteristics and technical specifications of the strip often occur. This can result in deviations in gloss. While the collection process is underway, the correction process is performed to correct the measured gloss.

[0134] Optionally, the method further includes a step 110 in which initial line conditions are set. This step is called the initial line setting step. As described above, the method sets the gloss range R s The measured gloss deviation exceeding a certain value is corrected. However, at the start of manufacturing activity on the coil coating line, or after significant changes such as strip type, paint thickness, paint color, or line speed, the line conditions may change, resulting in a set gloss value G s The line conditions may shift from those appropriate to reach the target. In such cases, the cooling module may not cool properly, and / or correct C p It may take some time to reach the corresponding output, and / or the wet film is corrected to temperature T c The UV radiation may not be strong enough to allow the desired gloss level to be reached. As a result, some of the coated strips may have to be discarded because the gloss is outside the specifications. Furthermore, the amount of UV radiation to which the wet film must be exposed to initiate the surface roughness that yields the set gloss value may not be appropriate. In such cases, the cooling module may need to compensate for the shifted UV radiation by, in some cases, cooling more strongly, which takes time. Again, some of the coated strips may have to be discarded because the gloss is outside the specifications. It is advantageous to set initial line conditions to minimize the length of coated strips that are outside the specifications.

[0135] To do so, in a first sub-step, several process parameters and / or specifications of the coated strip are collected. An example of a process parameter is the initial line speed LS0, preferably the recommended speed for the next coil to be coated on the coil coating line. Another example is the initial thickness FTh0 of the wet film applied onto the strip by the paint applicator. The initial film thickness preferably corresponds to the organic coating thickness specified for the next coil to be coated on the coil coating line. Another example is the temperature of the moving strip before the paint applicator, preferably before the inductor. Examples of specifications are the initial strip thickness STh0, the initial strip width SWd0, and the paint color. Preferably, the initial line speed LS0, initial thickness FTh0, initial strip thickness STh0, initial strip width SWd0, and paint color are collected. From a practical standpoint, the process parameters and / or specifications can be manually entered into a gloss control tool, particularly a setting module. Alternatively, they can be automatically obtained from and / or derived from the order book of the coil coating line, particularly a scheduling tool. For example, the initial film thickness FTh0 can be derived from the organic coating thickness specified in the order book.

[0136] Once process parameters and / or specifications are collected, initial line conditions are set in a second sub-process, taking the collected process parameters and / or specifications into account. In particular, they are calculated from the collected process parameters and / or specifications. The following initial line conditions may be set:

[0137] - Initial output of the cooling module PW0, - Initial UV dose D0 of the UV curing device, or, if applicable, the UV module, - The initial length L0 between the ultraviolet curing device, or UV module if applicable, and the electron beam curing device.

[0138] The initial power output PW0 can be set by knowing the mass flow rate of the moving strip, the specific heat capacity of the strip, and the cooling yield. The initial UV dose D0 can be set based on data obtained in a calibration process performed before the initial line setup process. The initial length L0 can be set based on data obtained in a calibration process performed before the initial line setup process.

[0139] From a practical standpoint, initial line conditions can be manually entered into the coil coating line control tool. Alternatively, they can be automatically injected by the gloss control tool within the coil coating line control tool.

[0140] In one variant, the initial line setting process 110 is performed before the setting process 100. This is done to set the gloss value G s and the set gloss range R s In addition to the initial combination, it helps to start production with line conditions already optimized for the first coil of manufacturing activity. During manufacturing, collection and correction processes may be performed to control gloss. Any one of the set parameters, in particular the set gloss value G s and / or set gloss range R s If any one of the specified gloss levels must be changed for any reason, such as a change in gloss or a change in the Radcure paint, the measured gloss level will be changed to the set gloss range R. s Maintaining this depends on the performance of the acquisition process 120 and the correction process 130.

[0141] In another variant, the initial line setting step 110 is performed after the setting step 100, as shown in Figure 2. In this way, the initial line conditions are set to the set gloss value G s This can be done by taking this into consideration. Therefore, the line conditions are better optimized for the first coil of the manufacturing activity. Furthermore, during manufacturing, any one of the set parameters, in particular the set gloss value G s and / or set gloss range R sIf any one of these needs to be changed for any reason, the initial line settings may be reset to help minimize the transition period.

[0142] In another variant, the initial line setup step 110 is performed before or after the setup step 100 in order to obtain the advantages of both variants described above.

[0143] In another variation, particularly during the continuous operation of a coil coating line, the initial line setup process may be performed in parallel with the collection process. In such continuous operation, since the strip consists of different coils mounted to each other from end to end, changes in the characteristics and technical specifications of the strip often occur. Reinitializing the line conditions when one of these changes occurs helps to reach the set gloss value as quickly as possible.

[0144] Next, a second embodiment of the present method will be described with reference to Figure 3.

[0145] In this embodiment, the correction step is - The temperature of the wet film upstream of the UV curing device is the minimum temperature T at which diffusion and / or migration phenomena are inhibited. min We guarantee that it will not fall below that, - Correct the deviation of the measured gloss G accordingly. It differs from the first one primarily in that it includes additional sub-processes.

[0146] This configuration ensures that the wet film responds appropriately to UV exposure.

[0147] Details provided in describing the first embodiment apply to the second embodiment. Additional steps and corresponding features are described in detail here.

[0148] Setting step 100 is the minimum temperature T of the Radcure paint. minThe process further includes setting the temperature. This temperature can be a temperature recommended by the paint supplier, or it can be identified during a calibration process performed before the setting process. During this calibration process, wet films of Radcure paint used on the coil coating line are cooled at different temperatures, cured by dual curing under standard curing conditions, and the gloss of the organic coating is measured. The temperature at which the wet film does not react to UV exposure is set to T min This can be achieved. From a practical standpoint, the minimum temperature T min This can be manually entered in the gloss control tool, particularly in the settings module. Alternatively, different minimum temperatures entered in the gloss control tool can be automatically obtained by matching them with paint standards from the coil coating line order book, particularly the scheduling tool.

[0149] The collection step 120 includes collecting measurements of the temperature T of the wet film in at least one width portion of the moving strip downstream of the cooling module and upstream of the ultraviolet curing device.

[0150] The acquisition step 120 further includes acquiring the UV dose D of the UV module. The output of the UV module is generally known from the operator and, in some cases, from the control tools of the coil coating line, but for a given output, the actual UV dose to which the wetted film is exposed varies with the line speed LS. Therefore, the UV dose is calculated and acquired based on the output of the UV module and the line speed. The line speed itself is generally known from the operator and, in some cases, from the control tools of the coil coating line.

[0151] Preferably, the UV dose is recalculated and collected each time either the output of the UV module and / or the line speed is adjusted. More preferably, the UV dose collection is substantially continuous. Preferably, the UV dose is collected automatically in a gloss control tool, particularly in the acquisition module, using a more suitable interface.

[0152] During correction process 130, correction C p The corrected temperature T before calculation c If it is calculated, then it is the minimum temperature T min This is compared to the corrected temperature T reached by the wet film in at least one width portion downstream of the cooling module and upstream of the UV curing device. c This may include a sub-step for calculating the correction C. p This can be done after the calculation, or at any other appropriate time. Once this sub-step is complete, T c The minimum temperature T min It can be compared to the minimum temperature T. min It can be compared to this.

[0153] T c (or T) is T min If the value exceeds this, the output of the cooling module is adjusted as detailed in the first embodiment.

[0154] T c (or T) is T min If it is lower than , the gloss must be corrected without further increasing the output of the cooling module. One way to do this is to adjust, in particular, the output of the UV module. This has been observed to actually affect the gloss of organic coatings. The lower the UV dose on the wet film, the higher the gloss. As a result, the correction step 130 is given by Equation 5: C D =f2(G,G s ) (5) Correction C is applied to the UV dose to which the wet film within at least one width portion of the moving strip must be exposed within the UV module. D This further includes the process of calculating [the result].

[0155] Equation (5) can be obtained in a calibration step performed before the correction step, preferably before the setting step. During this calibration step, wet films of the RadCure coating used on the coil coating line are exposed to different UV doses, cured by EB under standard curing conditions, and the gloss of the organic coating is measured. Thus, the function f2 can be derived for each RadCure coating. This calibration step only needs to be performed once and does not need to be performed each time the method according to the present invention is implemented. Alternatively, the function f2 can be G s This can be expressed as the PID function of the difference between the measured gloss G and the actual gloss G.

[0156] Preferably, a function f2 of a predetermined mathematical relationship between the UV dose to which the wet film of the RadCure coating is exposed and the gloss of the organic coating after electron beam curing is set during the setting process. "Predefined" means that the calibration process, preferably as described above, has been performed before carrying out the method on the coil coating line. The function f2 may be manually entered into a gloss control tool, particularly the setting module. Alternatively, a predetermined mathematical relationship entered into the gloss control tool may be automatically obtained by matching it with a coating standard from the coil coating line's order book, particularly the scheduling tool.

[0157] For example, in commercially available Radcure coatings for steel coil coatings, it has been observed that f2 is typically associated with a gloss curve that decreases asymptote as the UV dose increases.

[0158] Correction C applied to UV dose D Once calculated, the calculated correction C D Taking this into consideration, the line settings other than the cooling module output, other than the heating module output, and other than the inductor output, if applicable, are adjusted, and as a result, the measured gloss deviation is corrected.

[0159] In the modified form shown in Figure 3, the correction C applied to the UV dose is DWhen calculated, the output of the UV module is adjusted, specifically reduced, thereby reducing the UV dose D in the UV module within the wet film in at least one width portion of the moving strip. c =D+C D The film is exposed to UV radiation. By adjusting the UV module, the amount of UV radiation the wet film is exposed to in the width portion of the UV module is corrected, resulting in a gloss value of Gs on the organic coating in the width portion downstream of the electron beam curing device. The output of the UV module can be adjusted manually by the operator or automatically using a gloss control tool.

[0160] Next, a third embodiment of this method will be described with reference to Figure 4.

[0161] In this embodiment, the correction process is mainly, - UV dose D is the minimum UV dose to which the wet film can be exposed. min We guarantee that it will not fall below this level. - Correct the deviation of the measured gloss G accordingly. It differs from the second in that it includes additional sub-processes.

[0162] Thanks to this configuration, this method further prevents uncured wet film within the UV curing device, which could negatively affect gloss.

[0163] Details provided in describing the first and second embodiments apply to the third embodiment, where additional steps and corresponding features are described in detail.

[0164] In this embodiment, the UV module of the UV curing device in the coil coating line is movable along path P. Therefore, the length L between the UV module and the electron beam curing device can be adjusted.

[0165] Setting step 100 is the minimum UV dose D to which the wet film can be exposed in the UV module. minThe process further includes setting the UV dose. This UV dose may be one recommended by the paint supplier, or it may be identified by the operator of the coil coating line, particularly during the calibration process. From a practical standpoint, the minimum UV dose D min This can be manually entered into a gloss control tool, particularly the settings module. Alternatively, the different minimum UV doses entered into the gloss control tool can be automatically obtained by matching them with paint standards from the coil coating line order book, particularly the scheduling tool.

[0166] The collection step 120 further includes the step of collecting the length L between the UV module and the electron beam curing device. This length is generally known from the operator, and possibly from a control tool on the coil coating line. This can be collected manually. Preferably, it is collected automatically using a gloss control tool, more preferably with a suitable interface. Preferably, it is collected only when the length L has changed.

[0167] During correction process 130, correction C is applied to the UV dose. D Once calculated, the total D+C D (Hereinafter, D c (called) the minimum UV dose D min It is compared to D. c is D min If it exceeds the UV dose D in the UV module, the wet film in at least one width portion of the moving strip c The output / settings of the UV module are adjusted to expose the film to a specific UV radiation. The adjustment of the UV module corrects the UV dose to which the wet film is exposed in the width portion of the UV module, as in the second embodiment, resulting in a gloss of value Gs on the organic coating in the width portion downstream of the electron beam curing device.

[0168] D c is D minIf the UV dose falls below a certain level, the gloss must be corrected without further reducing the UV dose of the UV module. One way to do this is to adjust, especially shorten, the length between the UV module and the electron beam curing device. This has been observed to actually affect the gloss of organic coatings. The shorter the time between UV curing and EB curing, the higher the gloss. As a result, the correction step 130 is given by Equation 6: C L =f3(G,G s ) (6) Correction C applied to the length L between the UV module and the electron beam curing device accordingly. L This further includes the process of calculating [the result].

[0169] Equation (6) can be obtained in a calibration step performed before the correction step, preferably before the setting step. During this calibration step, a wet film of the RadCure coating to be used on the coil coating line is continuously exposed to UV curing and EB curing under standard curing conditions, the time between the two curings varies, and the gloss of the organic coating is measured. Thus, the function f3 can be derived for each RadCure coating. This calibration step only needs to be performed once and does not need to be performed each time the method according to the present invention is carried out. Alternatively, the function f3 can be G s This can be expressed as the PID function of the difference between the measured gloss G and the actual gloss G.

[0170] Preferably, a function f3 of a predetermined 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 the setup process. "Predefined" means that a calibration process, preferably as described above, has been performed before carrying out the method on the coil coating line. The function f3 may be manually entered into a gloss control tool, particularly the setup module. Alternatively, a predetermined mathematical relationship entered into the gloss control tool may be automatically obtained by matching it with paint standards from the coil coating line order book, particularly the scheduling tool.

[0171] For example, in the case of commercially available Radcure paints for coil coating of steel, it has been observed that f3 is usually related to a gloss curve that decreases towards an asymptote as L increases.

[0172] Correction C applied to the length between the UV module and the electron beam curing device L Once the calculated correction C L is taken into account, line settings other than the output of the cooling module, if applicable the output of the heating module, if applicable the output of the inductor, and the output of the UV module are adjusted, and as a result, the measured gloss deviation is corrected.

[0173] In the deformation mode shown in FIG. 4, once the correction C L is calculated, the length between the UV module and the electron beam curing device is set to a value G on the organic coating of at least one width portion of the moving strip downstream of the electron beam curing device s such that the gloss of the corrected length L c [[ID=१८]]= L + C L is adjusted, particularly shortened. The adjustment of the length can be done manually by an operator or automatically using a gloss management tool.

[0174] Alternatively, particularly when the length between the UV module and the electron beam curing device cannot be further extended or shortened, the line speed can be adjusted. In that case, the initial line settings can be made again to adjust the initial output PW0 of the cooling module, the initial UV dose D0 of the ultraviolet curing device, and the initial length L0 between the ultraviolet curing device and the electron beam curing device to the new line speed.

[0175] The present invention also relates to a method for forming an organic coating on a moving strip on a coil coating line, comprising, in sequence along the path P of the moving strip, a paint applicator, a cooling device comprising a cooling module, an ultraviolet curing device, and an electron beam curing device. - Applying a wet film of a radiation-curable paint onto a moving strip using a paint applicator; - Cooling the wet film of the radiation-curable paint within a cooling module; - Exposing the wet film of the radiation-curable paint to UV within an ultraviolet curing device; - Curing the wet film of the radiation-curable paint within an electron beam device to form an organic coating; comprising: The gloss of the organic coating is - a set gloss value G of the organic coating s and a set gloss range R of the gloss of the organic coating s are set; - Collecting measured values of the gloss G of the organic coating at at least one width portion downstream of the electron beam curing device; - Correcting a deviation of the measured gloss G exceeding the set gloss range R, the correction step comprising, using a closed-loop controller, calculating a correction C applied to the output of the cooling module in consideration of G s and the measured gloss G, and a sub-step of adjusting the settings of the coil coating line in consideration of the calculated correction C; s and a sub-step of adjusting the settings of the coil coating line in consideration of the calculated correction C; P and a sub-step of adjusting the settings of the coil coating line in consideration of the calculated correction C; P and a sub-step of adjusting the settings of the coil coating line in consideration of the calculated correction C; A method, which is controlled thereby.

[0176] All details provided with respect to the method for managing gloss and all details provided with respect to the coil coating line apply to the method for forming an organic coating.

[0177] The present invention also relates to a method for manufacturing a pre-coated metal comprising a metal strip and an organic coating on a coil coating line sequentially comprising a paint applicator, a cooling device comprising a cooling module, an ultraviolet curing device, and an electron beam curing device along a path P of a moving metal strip; - A step of applying a wet film of Radcure paint onto a moving metal strip using a paint applicator, - A process of cooling the wet film of Radcure coating within a cooling module, -A process of exposing a wetted film of RadCure coating to UV light within an ultraviolet curing device, - A process of curing a wetted film of RadCure coating within an electron beam device to form an organic coating, Includes, The gloss of the organic coating is - Gloss value G set for organic coating s and the set gloss range R of the organic coating s The process of setting up, - A step of collecting a measurement of the gloss G of the organic coating in at least one width portion downstream of the electron beam curing device, -Set gloss range R s A process for correcting the deviation of the measured gloss G that exceeds a certain value, wherein this correction process uses a closed-loop controller to correct the G s And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. P A sub-step to calculate the calculated correction C P A process including a sub-step that adjusts the coil coating line settings taking into consideration, Regarding the method of management.

[0178] Optionally, the metal strip may be heated before applying the wetted film of the Radcure coating.

[0179] All details provided in relation to methods for controlling gloss and all details provided in relation to coil coating lines apply to methods for manufacturing pre-painted metals.

Claims

1. A method for controlling the gloss of an organic coating formed by sequentially applying and curing a RadCure coating onto a wet film on a moving strip on a coil coating line, which comprises a coating applicator, a cooling device with a cooling module, an ultraviolet curing device, and an electron beam curing device, along a path P of the moving strip, Set gloss value G for organic coating ｓ and the set gloss range R of the organic coating ｓ The process of setting up, A step of collecting measurements of the gloss G of an organic coating in at least one width portion downstream of an electron beam curing device, Set gloss range R ｓ A process for correcting the deviation of the measured gloss G that exceeds a certain value, wherein this correction process uses a closed-loop controller to correct the G ｓ And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. Ｐ A sub-process to calculate the calculated correction C Ｐ A process including a sub-step of adjusting the coil coating line settings, taking into consideration, A method for controlling the gloss of organic coatings, including

2. The method according to claim 1, wherein the closed-loop controller is a proportional-integral-derivative controller.

3. Correction C Ｐ However, G ｓ The method according to any one of claims 1 or 2, wherein the difference between the measured gloss G is a function of the difference between the two.

4. Correction C applied to the output of the cooling module Ｐ is given by Equation 1 [Math 1] It is calculated according to, where K ｐ K is a proportional gain. ｉ is the integral gain, K ｄ e is the differential gain. １ is G ｓ This is the difference between the measured gloss G and the measured gloss G. The method according to any one of claims 1 to 3.

5. The collection step further includes collecting measurements of the temperature T of the wet film in at least one width portion of the moving strip downstream of the cooling module and upstream of the UV curing device, and the correction step includes collecting the corrected temperature T reached by the wet film in at least one width portion downstream of the cooling module and upstream of the UV curing device. ｃ The method according to any one of claims 1 or 2, further comprising a sub-step for calculating .

6. Corrected temperature T ｃ However, Equation 2: T ｃ =f １ (T,G,G ｓ ) (2) It is calculated according to the formula, where the function f １ This is a function of a predetermined mathematical relationship between the temperature of the wet film before UV curing and the gloss of the organic coating after electron beam curing. The method according to claim 5.

7. Corrected temperature T ｃ Equation 3: T ｃ =T+K(G-G ｓ ) (3) The method according to claim 5, calculated according to the method described in claim 5.

8. Correction C Ｐ However, T ｃ The method according to any one of claims 5 to 7, wherein the method is a function of the difference between and the measured temperature T.

9. Correction C applied to the output of the cooling module Ｐ However, equation 4 [Math 2] It is calculated according to, where K' ｐ is proportional gain, K' ｉ is the integral gain, K' ｄ e is the differential gain. ２ is T ｃ This is the difference between and the measured temperature T. The method according to any one of claims 5 to 7.

10. The sub-process for adjusting the coil coating line settings is called Correction C. Ｐ The method according to any one of claims 1 to 9, comprising adjusting the output of the cooling module accordingly.

11. The UV curing device is equipped with a UV module. The setting process involves the minimum temperature T of the Radcure paint. ｍｉｎ This further includes setting, The collection process further includes the step of collecting the UV dose D of the UV module, The sub-process for adjusting the coil coating line settings is: T ｃ ga T ｍｉｎ Evaluate whether it falls below this level, If it does not fall below, apply correction C. ｐ The output of the cooling module is adjusted accordingly. T Ｃ ga T ｍｉｎ If it falls below: Formula 5: C Ｄ =f ２ (G,G ｓ ) (5) Correction C is applied to the UV dose to which the wet film within at least one width portion in the UV module must be exposed. Ｄ Calculate, Calculated correction C Ｄ Taking this into consideration, this includes adjusting the settings of the coil coating lines other than the cooling module output, The method according to any one of claims 5 to 9.

12. A sub-step adjusts the settings of the coil coating lines other than the output of the cooling module, and the wet film of at least one width portion of the moving strip is corrected for UV dose D ｃ = D + C Ｄ The method according to claim 11, comprising adjusting the output of a UV module so that it is exposed to light.

13. The UV module is movable along path P. The setting process involves determining the minimum UV dose D to which the wet film can be exposed in the UV module. ｍｉｎ The process further includes setting up The collection step further includes a step of collecting the length L between the UV module and the electron beam curing device, The sub-process for adjusting the coil coating line settings other than the output of the cooling device is: D+C Ｄ is D ｍｉｎ Evaluate whether it falls below this level, If it does not fall below, the corrected UV dose D of the wet film within at least one width portion of the moving strip ｃ = D + C Ｄ Adjust the output of the UV module so that it is exposed to light. D+C Ｄ is D ｍｉｎ If it falls below: Formula 6: C Ｌ =f ３ (G,G ｓ ) (6) Correction C applied to the length between the UV module and the electron beam curing device accordingly. Ｌ Calculate, Calculated correction C Ｌ Taking this into consideration, a sub-process is included to adjust the settings of the coil coating lines other than the output of the cooling module and the output of the UV module. The method according to claim 11.

14. A sub-step that adjusts the settings of the coil coating lines other than the output of the cooling module and the output of the UV module adjusts the length L between the UV module and the electron beam curing device to a corrected length L. ｃ = L + C Ｌ This includes adjusting to the value G ｓ The method according to claim 13, wherein the gloss is obtained on the organic coating within at least one width portion of the moving strip downstream of the electron beam curing device.

15. A coil coating line comprising, in sequence, a paint applicator, a cooling device with a cooling module, an ultraviolet curing device, and an electron beam curing device, wherein the coil coating line further comprises a gloss control tool for controlling the gloss of an organic coating formed by the application and curing of Radcure paint onto a wet film on a moving strip on the coil coating line, and the gloss control tool is Set gloss value G for organic coating ｓ and the set gloss range R of the organic coating ｓ A configuration module for setting and An acquisition module for collecting measurements of gloss G of an organic coating in at least one width portion downstream of an electron beam curing device, Set gloss range R ｓ A correction module for correcting the deviation of measured gloss G that exceeds a certain value, wherein the correction is performed using a closed-loop controller, G ｓ And taking into account the measured gloss G, a correction C is applied to the output of the cooling module. Ｐ A sub-process to calculate the calculated correction C Ｐ A correction module, which includes a sub-step for adjusting the coil coating line settings taking into consideration, A coil coating line equipped with this feature.

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